Objective and Impact Statement:High-intensity focused ultrasound(HIFU)therapy is a promising noninvasive method that induces coagulative necrosis in diseased tissues through thermal and cavitation effects,while avoidi...Objective and Impact Statement:High-intensity focused ultrasound(HIFU)therapy is a promising noninvasive method that induces coagulative necrosis in diseased tissues through thermal and cavitation effects,while avoiding surrounding damage to surrounding normal tissues.Introduction:Accurate and real-time acquisition of the focal region temperature field during HIFU treatment marked enhances therapeutic efficacy,holding paramount scientific and practical value in clinical cancer therapy.Methods:In this paper,we initially designed and assembled an integrated HIFU system incorporating diagnostic,therapeutic,and temperature measurement functionalities to collect ultrasound echo signals and temperature variations during HIFU therapy.Furthermore,we introduced a novel multimodal teacher-student model approach,which utilizes the shared self-expressive coefficients and the deep canonical correlation analysis layer to aggregate each modality data,then through knowledge distillation strategies,transfers the knowledge from the teacher model to the student model.Results:By investigating the relationship between the phantoms,in vitro,and in vivo ultrasound echo signals and temperatures,we successfully achieved real-time reconstruction of the HIFU focal 2D temperature field region with a maximum temperature error of less than 2.5℃.Conclusion:Our method effectively monitored the distribution of the HIFU temperature field in real time,providing scientifically precise predictive schemes for HIFU therapy,laying a theoretical foundation for subsequent personalized treatment dose planning,and providing efficient guidance for noninvasive,nonionizing cancer treatment.展开更多
A low specific on-resistance SO1 LDMOS with a novel junction field plate （JFP） is proposed and investigated theo- retically. The most significant feature of the JFP LDMOS is a PP-N junction field plate instead of a ...A low specific on-resistance SO1 LDMOS with a novel junction field plate （JFP） is proposed and investigated theo- retically. The most significant feature of the JFP LDMOS is a PP-N junction field plate instead of a metal field plate. The unique structure not only yields charge compensation between the JFP and the drift region, but also modulates the surface electric field. In addition, a trench gate extends to the buffed oxide layer （BOX） and thus widens the vertical conduction area. As a result, the breakdown voltage （BV） is improved and the specific on-resistance （Ron,sp） is decreased significantly. It is demonstrated that the BV of 306 V and the Ron,sp of 7.43 mΩ.cm2 are obtained for the JFP LDMOS. Compared with those of the conventional LDMOS with the same dimensional parameters, the BV is improved by 34.8%, and the Ron,sp is decreased by 56.6% simultaneously. The proposed JFP LDMOS exhibits significant superiority in terms of the trade-off between BV and Ron,sp. The novel JFP technique offers an alternative technique to achieve high blocking voltage and large current capacity for power devices.展开更多
Computer vision(CV)is widely expected to be the next big thing in emerging applications.So many heterogeneous architectures for computer vision emerge.However,plenty of data need to be transferred between different st...Computer vision(CV)is widely expected to be the next big thing in emerging applications.So many heterogeneous architectures for computer vision emerge.However,plenty of data need to be transferred between different structures for heterogeneous architecture.The long data transfer delay becomes the mainly problem to limit the processing speed for computer vision applications.For reducing data transfer delay and fasting computer vision applications,a clustered data-driven array processor is proposed.A three-level pipelining processing element is designed which supports two-buffer data flow interface and 8 bits,16 bits,32 bits subtext parallel computation.At the same time,for accelerating transcendental function computation,a four-way shared pipelining transcendental function accelerator is designed,which is based on Y-intercept adjusted piecewise linear segment algorithm.A distributed shared memory structure based on unified addressing is also employed.To verify efficiency of architecture,some image processing algorithms are implemented on proposed architecture.Simultaneously the proposed architecture has been implemented on Xilinx ZC 706 development board.The same circuitry has been synthesized using SMIC 130 nm CMOS technology.The circuitry is able to run at 100 MHz.Area is 26.58 mm2.展开更多
A uniform doping ultra-thin silicon-on-insulator（SOI） lateral-double-diffused metal-oxide-semiconductor（LDMOS）with low specific on-resistance（R_on,sp） and high breakdown voltage（BV） is proposed and its mechani...A uniform doping ultra-thin silicon-on-insulator（SOI） lateral-double-diffused metal-oxide-semiconductor（LDMOS）with low specific on-resistance（R_on,sp） and high breakdown voltage（BV） is proposed and its mechanism is investigated.The proposed LDMOS features an accumulation-mode extended gate（AG） and back-side etching（BE）. The extended gate consists of a P– region and two diodes in series. In the on-state with VGD〉 0, an electron accumulation layer is formed along the drift region surface under the AG. It provides an ultra-low resistance current path along the whole drift region surface and thus the novel device obtains a low temperature distribution. The R_on,sp is nearly independent of the doping concentration of the drift region. In the off-state, the AG not only modulates the surface electric field distribution and improves the BV, but also brings in a charge compensation effect to further reduce the R_on,sp. Moreover, the BE avoids vertical premature breakdown to obtain high BV and allows a uniform doping in the drift region, which avoids the variable lateral doping（VLD） and the ＂hot-spot＂ caused by the VLD. Compared with the VLD SOI LDMOS, the proposed device simultaneously reduces the R_on,sp by 70.2% and increases the BV from 776 V to 818 V.展开更多
Geant4 Monte Carlo simulation results of the single event upset(SEU)induced by protons with energy ranging from 0.3 MeV to 1 GeV are reported.The SEU cross section for planar and three-dimensional(3D)die-stacked SRAM ...Geant4 Monte Carlo simulation results of the single event upset(SEU)induced by protons with energy ranging from 0.3 MeV to 1 GeV are reported.The SEU cross section for planar and three-dimensional(3D)die-stacked SRAM are calculated.The results show that the SEU cross sections of the planar device and the 3D device are different from each other under low energy proton direct ionization mechanism,but almost the same for the high energy proton.Besides,the multi-bit upset(MBU)ratio and pattern are presented and analyzed.The results indicate that the MBU ratio of the 3D die-stacked device is higher than that of the planar device,and the MBU patterns are more complicated.Finally,the on-orbit upset rate for the 3D die-stacked device and the planar device are calculated by SPACE RADIATION software.The calculation results indicate that no matter what the orbital parameters and shielding conditions are,the on-orbit upset rate of planar device is higher than that of 3D die-stacked device.展开更多
A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is p...A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration （Am）. In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp. Especially, the two PNjunctions within the trench gate support a high gate--drain voltage in the off-state and on-state, re- spectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS （CSJ-VDMOS） at the same high breakdown voltage （BV）.展开更多
We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost indep...We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume.展开更多
It is understood that the sparse signal recovery with a standard compressive sensing（CS） strategy requires the measurement matrix known as a priori. The measurement matrix is, however, often perturbed in a practical...It is understood that the sparse signal recovery with a standard compressive sensing（CS） strategy requires the measurement matrix known as a priori. The measurement matrix is, however, often perturbed in a practical application.In order to handle such a case, an optimization problem by exploiting the sparsity characteristics of both the perturbations and signals is formulated. An algorithm named as the sparse perturbation signal recovery algorithm（SPSRA） is then proposed to solve the formulated optimization problem. The analytical results show that our SPSRA can simultaneously recover the signal and perturbation vectors by an alternative iteration way, while the convergence of the SPSRA is also analytically given and guaranteed. Moreover, the support patterns of the sparse signal and structured perturbation shown are the same and can be exploited to improve the estimation accuracy and reduce the computation complexity of the algorithm. The numerical simulation results verify the effectiveness of analytical ones.展开更多
Ni/Au Schottky contacts on A1N/GaN and A1GaN/GaN heterostructures are fabricated. Based on the measured current-voltage and capacitance-voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as...Ni/Au Schottky contacts on A1N/GaN and A1GaN/GaN heterostructures are fabricated. Based on the measured current-voltage and capacitance-voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as Schottky barrier height, turn-on voltage, reverse breakdown voltage, ideal factor, and the current-transport mechanism, are analyzed and then compared with those of an A1GaN/GaN diode by self-consistently solving Schrodinger＇s and Poisson＇s equations. It is found that the dislocation-governed tunneling is dominant for both AlN/GaN and AlGaN/GaN Schottky diodes. However, more dislocation defects and a thinner barrier layer for AlN/GaN heterostrncture results in a larger tunneling probability, and causes a larger leakage current and lower reverse breakdown voltage, even though the Schottky barrier height of AlN/GaN Schottky diode is calculated to be higher that of an A1GaN/GaN diode.展开更多
Using measured capacitance-voltage curves and current-voltage characteristics for the AlGaN/AlN/GaN heterostructure field-effect transistors with different gate lengths and drain-to-source distances, the influence of ...Using measured capacitance-voltage curves and current-voltage characteristics for the AlGaN/AlN/GaN heterostructure field-effect transistors with different gate lengths and drain-to-source distances, the influence of drain bias on the electron mobility is investigated. It is found that below the knee voltage the longitudinal optical （LO） phonon scattering and interface roughness scattering are dominant for the sample with a large ratio of gate length to drain-to-source distance （here 4/5）, and the polarization Coulomb field scattering is dominant for the sample with a small ratio （here 1/5）. However, the above polarization Coulomb field scattering is weakened in the sample with a small drain-to-source distance （here 20 μm） compared with the one with a large distance （here 100 μm）. This is due to the induced strain in the AlGaN layer caused by the drain bias.展开更多
A low specific on-resistance（Ron,sp） integrable silicon-on-insulator（SOI） metal-oxide semiconductor field-effect transistor（MOSFET） is proposed and investigated by simulation.The MOSFET features a recessed drain...A low specific on-resistance（Ron,sp） integrable silicon-on-insulator（SOI） metal-oxide semiconductor field-effect transistor（MOSFET） is proposed and investigated by simulation.The MOSFET features a recessed drain as well as dual gates,which consist of a planar gate and a trench gate extended to the buried oxide layer（BOX）（DGRD MOSFET）.First,the dual gates form dual conduction channels,and the extended trench gate also acts as a field plate to improve the electric field distribution.Second,the combination of the trench gate and the recessed drain widens the vertical conduction area and shortens the current path.Third,the P-type top layer not only enhances the drift doping concentration but also modulates the surface electric field distributions.All of these sharply reduce Ron,sp and maintain a high breakdown voltage（BV）.The BV of 233 V and Ron,sp of 4.151 mΩ·cm2（VGS = 15 V） are obtained for the DGRD MOSFET with 15-μm half-cell pitch.Compared with the trench gate SOI MOSFET and the conventional MOSFET,Ron,sp of the DGRD MOSFET decreases by 36% and 33% with the same BV,respectively.The trench gate extended to the BOX synchronously acts as a dielectric isolation trench,simplifying the fabrication processes.展开更多
A novel lateral double-diffused metal–oxide semiconductor（LDMOS） with a high breakdown voltage（BV） and low specific on-resistance（Ron.sp） is proposed and investigated by simulation. It features a junction field...A novel lateral double-diffused metal–oxide semiconductor（LDMOS） with a high breakdown voltage（BV） and low specific on-resistance（Ron.sp） is proposed and investigated by simulation. It features a junction field plate（JFP） over the drift region and a partial N-buried layer（PNB） in the P-substrate. The JFP not only smoothes the surface electric field（E-field）, but also brings in charge compensation between the JFP and the N-drift region, which increases the doping concentration of the N-drift region. The PNB reshapes the equipotential contours, and thus reduces the E-field peak on the drain side and increases that on the source side. Moreover, the PNB extends the depletion width in the substrate by introducing an additional vertical diode, resulting in a significant improvement on the vertical BV. Compared with the conventional LDMOS with the same dimensional parameters, the novel LDMOS has an increase in BV value by 67.4%,and a reduction in Ron.sp by 45.7% simultaneously.展开更多
The design strategy and efficiency optimization of a Ge-based n-type metal-oxide-semiconductor field-effect transistor(n-MOSFET)with a Si_(0.14)Ge_(0.72)Sn_(0.14)-Ge_(0.82)Sn_(0.18)-Ge quantum structure used for 2.45 ...The design strategy and efficiency optimization of a Ge-based n-type metal-oxide-semiconductor field-effect transistor(n-MOSFET)with a Si_(0.14)Ge_(0.72)Sn_(0.14)-Ge_(0.82)Sn_(0.18)-Ge quantum structure used for 2.45 GHz weak energy microwave wireless energy transmission is reported.The quantum structure combined withδ-doping technology is used to reduce the scattering of the device and improve its electron mobility;at the same time,the generation of surface channels is suppressed by the Si_(0.14)Ge_(0.72)Sn_(0.14) cap layer.By adjusting the threshold voltage of the device to 91 mV,setting the device aspect ratio to 1μm/0.4μm and adopting a novel diode connection method,the rectification efficiency of the device is improved.With simulation by Silvaco TCAD software,good performance is displayed in the transfer and output characteristics.For a simple half-wave rectifier circuit with a load of 1 pf and 20 kΩ,the rectification efficiency of the device can reach 7.14%at an input power of-10 dBm,which is 4.2 times that of a Si MOSFET(with a threshold voltage of 80 mV)under the same conditions;this device shows a better rectification effect than a Si MOSFET in the range of-30 dBm to 6.9 dBm.展开更多
Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and...Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and the data delay increases dramatically. With the advent of optical router, the traditional electrical interconnection mode has changed to optical interconnection mode. In the packet switched optical interconnection network, the data communication mechanism consists of 3 processes: link establishment, data transmission and link termination, but the circuit-switched data transmission method greatly limits the utilization of resources. The number of micro-ring resonators in the on-chip large-scale optical interconnect network is an important parameter affecting the insertion loss. The proposed λ-route, GWOR, Crossbar structure has a large overall network insertion loss due to the use of many micro-ring resonators. How to use the least micro-ring resonator to realize non-blocking communication between multiple cores has been a research hotspot. In order to improve bandwidth and reduce access latency, an optical interconnection structure called multilevel switching optical network on chip(MSONoC) is proposed in this paper. The broadband micro-ring resonators(BMRs) are employed to reduce the number of micro-ring resonators(MRs) in the network, and the structure can provide the service of non-blocking point to point communication with the wavelength division multiplexing(WDM) technology. The results show that compared to λ-route, GWOR, Crossbar and the new topology structure, the number of micro-ring resonators of MSONoC are reduced by 95.5%, 95.5%, 87.5%, and 60% respectively. The insertion loss of the minimum link of new topology, mesh and MSONoC structure is 0.73 dB, 0.725 dB and 0.38 dB.展开更多
The Rate Distortion Optimization(RDO)algorithm in High Efficiency Video Coding(HEVC)has many iterations and a large number of calculations.In order to decrease the calculation time and meet the requirements of fast sw...The Rate Distortion Optimization(RDO)algorithm in High Efficiency Video Coding(HEVC)has many iterations and a large number of calculations.In order to decrease the calculation time and meet the requirements of fast switching of RDO algorithms of different scales,an RDO dynamic reconfigurable structure is proposed.First,the Quantization Parameter(QP)and bit rate values were loaded through an H⁃tree Configurable Network(HCN),and the execution status of the array was detected in real time.When the switching request of the RDO algorithm was detected,the corresponding configuration information was delivered.This self⁃reconfiguration implementation method improved the flexibility and utilization of hardware.Experimental results show that when the control bit width was only increased by 31.25%,the designed configuration network could increase the number of controllable processing units by 32 times,and the execution cycle was 50%lower than the same type of design.Compared with previous RDO algorithm,the RDO algorithm implemented on the reconfigurable array based on the configuration network had an average operating frequency increase of 12.5%and an area reduction of 56.4%.展开更多
According to the international guidelines for proton single event effect ground test,the single event upset(SEU)cross-section induced by protons with energy levels around 200 MeV is widely recognized as the saturation...According to the international guidelines for proton single event effect ground test,the single event upset(SEU)cross-section induced by protons with energy levels around 200 MeV is widely recognized as the saturation SEU cross-section^([1,2]),which serves as the fundamental basis for predicting error rates of devices in realistic proton radiation environments.展开更多
Phosphor-in-glassfilm(PiF)based on sapphire substrate(SS)is a promising laser-driven color converter.Herein,by using an optimized silicon borate glass component,high-performance Y3Al5O12:Ce3þPiFs are successfully...Phosphor-in-glassfilm(PiF)based on sapphire substrate(SS)is a promising laser-driven color converter.Herein,by using an optimized silicon borate glass component,high-performance Y3Al5O12:Ce3þPiFs are successfully prepared on bothflat sapphire substrate(FSS)and patterned sapphire substrate(PSS)surfaces.Compared with planar structure of FSS,PSS has a periodic arrangement of conical structures on its surface,which effectively increases the contact area between the PiF and the substrate by approximately 56%,thereby forming a more robustfilm composite structure.The blue laser light is affected by the structure of PSS and produces a typical diffraction effect,which realizes the dispersion of the convergent beam.This significantly expands the laser spot on PSS-PiF and improves the uniformity of light.The saturation power density of PiF-PSS(6.29 W/mm^(2))is found to be 91%higher than that of PiF-FSS,while maintaining a high luminous efficiency(220 lm/W)and a low correlated color temperature(4500 K).Finally,the thermal quenching mechanism of PiF with different substrate surface morphologies is compared and analyzed.The present results provide important support for designing the interface structure between SSs and PiF to achieve higher efficiency and higher saturation threshold for warm white light.展开更多
To meet the growing demand for wearable smart electronic devices,the development of flexible lithium-ion batteries(LIBs)is essential.Silicon is an ideal candidate for the anode material of flexible lithium-ion batteri...To meet the growing demand for wearable smart electronic devices,the development of flexible lithium-ion batteries(LIBs)is essential.Silicon is an ideal candidate for the anode material of flexible lithium-ion batteries due to its high specific capacity,low working potential,and earth abundance.The largest challenge in developing a flexible silicon anode is how to maintain structural integrity and ensure stable electrochemical reactions during external deformation.In this work,we propose a novel design for fabricating core–shell electrodes based on a copper nanowire(CuNW)array core and magnetron sputtered Si/C shell.The nanowire array structure has characteristics of bending under longitudinal stress and twisting under transverse stress,which helps to maintain the mechanical stability of the structure during electrode bending and cycling.The low-temperature annealing generates a small amount of Cu3Si alloy,which enhances the connection strength between Si and the conductive network and solves the poor conductivity problem of Si,which is known as a semiconductor material.This unique configuration design of CuNW@Si@C-400℃ leads to stable long cycle performance of 1109 mAh∙g^(-1) after 1000 cycles and excellent rate performance of 500 mAh∙g^(-1) at a current density of 10 A∙g^(-1).Furthermore,the CuNW@Si@C-400℃||LiFePO_(4)(LFP)full battery demonstrates excellent flexibility,with a capacity retention of more than 96%after 100 bends.This study provides a promising strategy for the development of flexible lithium-ion batteries.展开更多
Single event irradiation-hardened power MOSFET is the most important device for DC/DC converter in space environment application. Single event gate rupture （SEGR） and single event burnout （SEB）, which will degrade...Single event irradiation-hardened power MOSFET is the most important device for DC/DC converter in space environment application. Single event gate rupture （SEGR） and single event burnout （SEB）, which will degrade the running safety and reliability of spacecraft, are the two typical failure modes in power MOSFETs. In this paper, based on recombination mechanism of interface between oxide and silicon, a novel hardened power MOS- FETs structure for SEGR and SEB is proposed. The structure comprises double stagger partial silicon-on-insulator （DSPSOI） layers. Results show that the safety operation area （SOA） of a 130 V N-channel power MOSFET in single event irradiation environment is enhanced by up to 50% when the linear-energy-transfer value of heavy ion is a constant of 98 MeV-cm2/mg in the whole incident track, and the other parameters are almost maintained at the same value. Thus this novel structure can be widely used in designing single event irradiation-hardened power MOSFETs.展开更多
The addition of a buffer layer can improve the device＇s secondary breakdown voltage, thus, improving the single event burnout （SEB） threshold voltage. In this paper, an N type linear doping buffer layer is proposed...The addition of a buffer layer can improve the device＇s secondary breakdown voltage, thus, improving the single event burnout （SEB） threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an op- timized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer ~ayer. So the linear buffer layer is more advantageous to improving the device＇s SEB performance.展开更多
基金supported in part by the Natural Science Foundation of China(No.U22A20259)the Shenzhen Basic Science Research(No.JCYJ20200109110006136)the Interdisciplinary Research Program of Hust 2023JCYJ043.
文摘Objective and Impact Statement:High-intensity focused ultrasound(HIFU)therapy is a promising noninvasive method that induces coagulative necrosis in diseased tissues through thermal and cavitation effects,while avoiding surrounding damage to surrounding normal tissues.Introduction:Accurate and real-time acquisition of the focal region temperature field during HIFU treatment marked enhances therapeutic efficacy,holding paramount scientific and practical value in clinical cancer therapy.Methods:In this paper,we initially designed and assembled an integrated HIFU system incorporating diagnostic,therapeutic,and temperature measurement functionalities to collect ultrasound echo signals and temperature variations during HIFU therapy.Furthermore,we introduced a novel multimodal teacher-student model approach,which utilizes the shared self-expressive coefficients and the deep canonical correlation analysis layer to aggregate each modality data,then through knowledge distillation strategies,transfers the knowledge from the teacher model to the student model.Results:By investigating the relationship between the phantoms,in vitro,and in vivo ultrasound echo signals and temperatures,we successfully achieved real-time reconstruction of the HIFU focal 2D temperature field region with a maximum temperature error of less than 2.5℃.Conclusion:Our method effectively monitored the distribution of the HIFU temperature field in real time,providing scientifically precise predictive schemes for HIFU therapy,laying a theoretical foundation for subsequent personalized treatment dose planning,and providing efficient guidance for noninvasive,nonionizing cancer treatment.
基金supported by the National Natural Science Foundation of China(Grant No.61376079)the Postdoctoral Science Foundation of China(GrantNo.2012T50771)the Postdoctoral Science Foundation of Chongqing City,China(Grant No.XM2012004)
文摘A low specific on-resistance SO1 LDMOS with a novel junction field plate （JFP） is proposed and investigated theo- retically. The most significant feature of the JFP LDMOS is a PP-N junction field plate instead of a metal field plate. The unique structure not only yields charge compensation between the JFP and the drift region, but also modulates the surface electric field. In addition, a trench gate extends to the buffed oxide layer （BOX） and thus widens the vertical conduction area. As a result, the breakdown voltage （BV） is improved and the specific on-resistance （Ron,sp） is decreased significantly. It is demonstrated that the BV of 306 V and the Ron,sp of 7.43 mΩ.cm2 are obtained for the JFP LDMOS. Compared with those of the conventional LDMOS with the same dimensional parameters, the BV is improved by 34.8%, and the Ron,sp is decreased by 56.6% simultaneously. The proposed JFP LDMOS exhibits significant superiority in terms of the trade-off between BV and Ron,sp. The novel JFP technique offers an alternative technique to achieve high blocking voltage and large current capacity for power devices.
基金the National Natural Science Foundation of China(No.61802304,61834005,61772417,61634004,61602377)Shaanxi Provincial Co-ordination Innovation Project of Science and Technology(No.2016KTZDGY02-04-02)+1 种基金Shaanxi Provincial Key R&D Plan(No.2017GY-060)Shaanxi International Science and Technology Cooperation Program(No.2018KW-006).
文摘Computer vision(CV)is widely expected to be the next big thing in emerging applications.So many heterogeneous architectures for computer vision emerge.However,plenty of data need to be transferred between different structures for heterogeneous architecture.The long data transfer delay becomes the mainly problem to limit the processing speed for computer vision applications.For reducing data transfer delay and fasting computer vision applications,a clustered data-driven array processor is proposed.A three-level pipelining processing element is designed which supports two-buffer data flow interface and 8 bits,16 bits,32 bits subtext parallel computation.At the same time,for accelerating transcendental function computation,a four-way shared pipelining transcendental function accelerator is designed,which is based on Y-intercept adjusted piecewise linear segment algorithm.A distributed shared memory structure based on unified addressing is also employed.To verify efficiency of architecture,some image processing algorithms are implemented on proposed architecture.Simultaneously the proposed architecture has been implemented on Xilinx ZC 706 development board.The same circuitry has been synthesized using SMIC 130 nm CMOS technology.The circuitry is able to run at 100 MHz.Area is 26.58 mm2.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61176069 and 61376079)
文摘A uniform doping ultra-thin silicon-on-insulator（SOI） lateral-double-diffused metal-oxide-semiconductor（LDMOS）with low specific on-resistance（R_on,sp） and high breakdown voltage（BV） is proposed and its mechanism is investigated.The proposed LDMOS features an accumulation-mode extended gate（AG） and back-side etching（BE）. The extended gate consists of a P– region and two diodes in series. In the on-state with VGD〉 0, an electron accumulation layer is formed along the drift region surface under the AG. It provides an ultra-low resistance current path along the whole drift region surface and thus the novel device obtains a low temperature distribution. The R_on,sp is nearly independent of the doping concentration of the drift region. In the off-state, the AG not only modulates the surface electric field distribution and improves the BV, but also brings in a charge compensation effect to further reduce the R_on,sp. Moreover, the BE avoids vertical premature breakdown to obtain high BV and allows a uniform doping in the drift region, which avoids the variable lateral doping（VLD） and the ＂hot-spot＂ caused by the VLD. Compared with the VLD SOI LDMOS, the proposed device simultaneously reduces the R_on,sp by 70.2% and increases the BV from 776 V to 818 V.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11690041 and 11675233)the Fund from the Science and Technology on Analog Integrated Circuit Laboratory,China(Grant No.JCKY2019210C054).
文摘Geant4 Monte Carlo simulation results of the single event upset(SEU)induced by protons with energy ranging from 0.3 MeV to 1 GeV are reported.The SEU cross section for planar and three-dimensional(3D)die-stacked SRAM are calculated.The results show that the SEU cross sections of the planar device and the 3D device are different from each other under low energy proton direct ionization mechanism,but almost the same for the high energy proton.Besides,the multi-bit upset(MBU)ratio and pattern are presented and analyzed.The results indicate that the MBU ratio of the 3D die-stacked device is higher than that of the planar device,and the MBU patterns are more complicated.Finally,the on-orbit upset rate for the 3D die-stacked device and the planar device are calculated by SPACE RADIATION software.The calculation results indicate that no matter what the orbital parameters and shielding conditions are,the on-orbit upset rate of planar device is higher than that of 3D die-stacked device.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176069 and 61376079)the Fundamental Research Funds for the Central Universities,China(Grant No.ZYGX2014Z006)
文摘A new ultra-low specific on-resistance （Ron,sp） vertical double diffusion metal-oxide-semiconductor field-effect tran- sistor （VDMOS） with continuous electron accumulation （CEA） layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the Ron,sp but also makes the Ron,sp almost independent of the n-pillar doping concentration （Am）. In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the Nn, and further reduces the Ron,sp. Especially, the two PNjunctions within the trench gate support a high gate--drain voltage in the off-state and on-state, re- spectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the Ron,sp by 80% compared with the conventional super-junction VDMOS （CSJ-VDMOS） at the same high breakdown voltage （BV）.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775167 and 12105252)the Natural Science Foundation of Chongqing,China(Grant No.cstc2021jcyj-bsh0246)。
文摘We investigate the angular dependence of proton-induced single event transient(SET) in silicon-germanium heterojunction bipolar transistors. Experimental results show that the overall SET cross section is almost independent of proton incident angle. However, the proportion of SET events with long duration and high integral charge collection grows significantly with the increasing angle. Monte Carlo simulations demonstrate that the integral cross section of proton incident events with high ionizing energy deposition in the sensitive volume tends to be higher at larger incident angles, which is associated with the angular distribution of proton-induced secondary particles and the geometry of sensitive volume.
基金supported by the National Natural Science Foundation of China(61171127)
文摘It is understood that the sparse signal recovery with a standard compressive sensing（CS） strategy requires the measurement matrix known as a priori. The measurement matrix is, however, often perturbed in a practical application.In order to handle such a case, an optimization problem by exploiting the sparsity characteristics of both the perturbations and signals is formulated. An algorithm named as the sparse perturbation signal recovery algorithm（SPSRA） is then proposed to solve the formulated optimization problem. The analytical results show that our SPSRA can simultaneously recover the signal and perturbation vectors by an alternative iteration way, while the convergence of the SPSRA is also analytically given and guaranteed. Moreover, the support patterns of the sparse signal and structured perturbation shown are the same and can be exploited to improve the estimation accuracy and reduce the computation complexity of the algorithm. The numerical simulation results verify the effectiveness of analytical ones.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.60890192,60876009,and 11174182)
文摘Ni/Au Schottky contacts on A1N/GaN and A1GaN/GaN heterostructures are fabricated. Based on the measured current-voltage and capacitance-voltage curves, the electrical characteristics of AlN/GaN Schottky diode, such as Schottky barrier height, turn-on voltage, reverse breakdown voltage, ideal factor, and the current-transport mechanism, are analyzed and then compared with those of an A1GaN/GaN diode by self-consistently solving Schrodinger＇s and Poisson＇s equations. It is found that the dislocation-governed tunneling is dominant for both AlN/GaN and AlGaN/GaN Schottky diodes. However, more dislocation defects and a thinner barrier layer for AlN/GaN heterostrncture results in a larger tunneling probability, and causes a larger leakage current and lower reverse breakdown voltage, even though the Schottky barrier height of AlN/GaN Schottky diode is calculated to be higher that of an A1GaN/GaN diode.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11174182 and 10774090)
文摘Using measured capacitance-voltage curves and current-voltage characteristics for the AlGaN/AlN/GaN heterostructure field-effect transistors with different gate lengths and drain-to-source distances, the influence of drain bias on the electron mobility is investigated. It is found that below the knee voltage the longitudinal optical （LO） phonon scattering and interface roughness scattering are dominant for the sample with a large ratio of gate length to drain-to-source distance （here 4/5）, and the polarization Coulomb field scattering is dominant for the sample with a small ratio （here 1/5）. However, the above polarization Coulomb field scattering is weakened in the sample with a small drain-to-source distance （here 20 μm） compared with the one with a large distance （here 100 μm）. This is due to the induced strain in the AlGaN layer caused by the drain bias.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61176069)the Science Foundation from the State Key Laboratory of Electronic Thin Films and Integrated Devices (Grant No. CXJJ201004)the Fund from the National Key Laboratory of Analog Integrated Circuit (Grant No. 9140C090304110C0905)
文摘A low specific on-resistance（Ron,sp） integrable silicon-on-insulator（SOI） metal-oxide semiconductor field-effect transistor（MOSFET） is proposed and investigated by simulation.The MOSFET features a recessed drain as well as dual gates,which consist of a planar gate and a trench gate extended to the buried oxide layer（BOX）（DGRD MOSFET）.First,the dual gates form dual conduction channels,and the extended trench gate also acts as a field plate to improve the electric field distribution.Second,the combination of the trench gate and the recessed drain widens the vertical conduction area and shortens the current path.Third,the P-type top layer not only enhances the drift doping concentration but also modulates the surface electric field distributions.All of these sharply reduce Ron,sp and maintain a high breakdown voltage（BV）.The BV of 233 V and Ron,sp of 4.151 mΩ·cm2（VGS = 15 V） are obtained for the DGRD MOSFET with 15-μm half-cell pitch.Compared with the trench gate SOI MOSFET and the conventional MOSFET,Ron,sp of the DGRD MOSFET decreases by 36% and 33% with the same BV,respectively.The trench gate extended to the BOX synchronously acts as a dielectric isolation trench,simplifying the fabrication processes.
基金Project supported by the National Natural Science Foundation of China(Grant No.61376079)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-11-0062)the Postdoctoral Science Foundation of China(Grant Nos.2012T50771 and XM2012004)
文摘A novel lateral double-diffused metal–oxide semiconductor（LDMOS） with a high breakdown voltage（BV） and low specific on-resistance（Ron.sp） is proposed and investigated by simulation. It features a junction field plate（JFP） over the drift region and a partial N-buried layer（PNB） in the P-substrate. The JFP not only smoothes the surface electric field（E-field）, but also brings in charge compensation between the JFP and the N-drift region, which increases the doping concentration of the N-drift region. The PNB reshapes the equipotential contours, and thus reduces the E-field peak on the drain side and increases that on the source side. Moreover, the PNB extends the depletion width in the substrate by introducing an additional vertical diode, resulting in a significant improvement on the vertical BV. Compared with the conventional LDMOS with the same dimensional parameters, the novel LDMOS has an increase in BV value by 67.4%,and a reduction in Ron.sp by 45.7% simultaneously.
基金supported by the National 111 Center(Grant No.B12026)Research on***Technology of Intelligent Reconfigurable General System(Grant No.F020250058)。
文摘The design strategy and efficiency optimization of a Ge-based n-type metal-oxide-semiconductor field-effect transistor(n-MOSFET)with a Si_(0.14)Ge_(0.72)Sn_(0.14)-Ge_(0.82)Sn_(0.18)-Ge quantum structure used for 2.45 GHz weak energy microwave wireless energy transmission is reported.The quantum structure combined withδ-doping technology is used to reduce the scattering of the device and improve its electron mobility;at the same time,the generation of surface channels is suppressed by the Si_(0.14)Ge_(0.72)Sn_(0.14) cap layer.By adjusting the threshold voltage of the device to 91 mV,setting the device aspect ratio to 1μm/0.4μm and adopting a novel diode connection method,the rectification efficiency of the device is improved.With simulation by Silvaco TCAD software,good performance is displayed in the transfer and output characteristics.For a simple half-wave rectifier circuit with a load of 1 pf and 20 kΩ,the rectification efficiency of the device can reach 7.14%at an input power of-10 dBm,which is 4.2 times that of a Si MOSFET(with a threshold voltage of 80 mV)under the same conditions;this device shows a better rectification effect than a Si MOSFET in the range of-30 dBm to 6.9 dBm.
基金Supported by the National Natural Science Foundation of China(No.61834005,61772417,61802304,61602377,61634004)Shaanxi Provincial Co-ordination Innovation Project of Science and Technology(No.2016KTZDGY02-04-02)+1 种基金Shaanxi Provincial Key R&D Plan(No.2017GY-060)Shaanxi International Science and Technology Cooperation Program(No.2018KW-006).
文摘Electric router is widely used for multi-core system to interconnect each other. However, with the increasing number of processor cores, the probability of communication conflict between processor cores increases, and the data delay increases dramatically. With the advent of optical router, the traditional electrical interconnection mode has changed to optical interconnection mode. In the packet switched optical interconnection network, the data communication mechanism consists of 3 processes: link establishment, data transmission and link termination, but the circuit-switched data transmission method greatly limits the utilization of resources. The number of micro-ring resonators in the on-chip large-scale optical interconnect network is an important parameter affecting the insertion loss. The proposed λ-route, GWOR, Crossbar structure has a large overall network insertion loss due to the use of many micro-ring resonators. How to use the least micro-ring resonator to realize non-blocking communication between multiple cores has been a research hotspot. In order to improve bandwidth and reduce access latency, an optical interconnection structure called multilevel switching optical network on chip(MSONoC) is proposed in this paper. The broadband micro-ring resonators(BMRs) are employed to reduce the number of micro-ring resonators(MRs) in the network, and the structure can provide the service of non-blocking point to point communication with the wavelength division multiplexing(WDM) technology. The results show that compared to λ-route, GWOR, Crossbar and the new topology structure, the number of micro-ring resonators of MSONoC are reduced by 95.5%, 95.5%, 87.5%, and 60% respectively. The insertion loss of the minimum link of new topology, mesh and MSONoC structure is 0.73 dB, 0.725 dB and 0.38 dB.
基金Sponsored by the National Natural Science Foundation of China(Grant Nos.61834005,61772417,61802304,61602377,and 61634004)the Shaanxi Province Coordination Innovation Project of Science and Technology(Grant No.2016KTZDGY02-04-02)+1 种基金the Shaanxi Provincial Key R&D Plan(Grant No.2017GY-060)the Shaanxi International Science and Technology Cooperation Program(Grant No.2018KW-006).
文摘The Rate Distortion Optimization(RDO)algorithm in High Efficiency Video Coding(HEVC)has many iterations and a large number of calculations.In order to decrease the calculation time and meet the requirements of fast switching of RDO algorithms of different scales,an RDO dynamic reconfigurable structure is proposed.First,the Quantization Parameter(QP)and bit rate values were loaded through an H⁃tree Configurable Network(HCN),and the execution status of the array was detected in real time.When the switching request of the RDO algorithm was detected,the corresponding configuration information was delivered.This self⁃reconfiguration implementation method improved the flexibility and utilization of hardware.Experimental results show that when the control bit width was only increased by 31.25%,the designed configuration network could increase the number of controllable processing units by 32 times,and the execution cycle was 50%lower than the same type of design.Compared with previous RDO algorithm,the RDO algorithm implemented on the reconfigurable array based on the configuration network had an average operating frequency increase of 12.5%and an area reduction of 56.4%.
基金National Natural Science Foundation of China(12105339,12035019,62174180)National Laboratory of Science and Technology on Analog Integrated Circuit(2021-JCJQ-LB-049-9)。
文摘According to the international guidelines for proton single event effect ground test,the single event upset(SEU)cross-section induced by protons with energy levels around 200 MeV is widely recognized as the saturation SEU cross-section^([1,2]),which serves as the fundamental basis for predicting error rates of devices in realistic proton radiation environments.
基金the National Natural Science Foundation of China(Nos.U21A20493,62234011 and 62104204)the President's Foundation of Xiamen University(No.20720220108).
文摘Phosphor-in-glassfilm(PiF)based on sapphire substrate(SS)is a promising laser-driven color converter.Herein,by using an optimized silicon borate glass component,high-performance Y3Al5O12:Ce3þPiFs are successfully prepared on bothflat sapphire substrate(FSS)and patterned sapphire substrate(PSS)surfaces.Compared with planar structure of FSS,PSS has a periodic arrangement of conical structures on its surface,which effectively increases the contact area between the PiF and the substrate by approximately 56%,thereby forming a more robustfilm composite structure.The blue laser light is affected by the structure of PSS and produces a typical diffraction effect,which realizes the dispersion of the convergent beam.This significantly expands the laser spot on PSS-PiF and improves the uniformity of light.The saturation power density of PiF-PSS(6.29 W/mm^(2))is found to be 91%higher than that of PiF-FSS,while maintaining a high luminous efficiency(220 lm/W)and a low correlated color temperature(4500 K).Finally,the thermal quenching mechanism of PiF with different substrate surface morphologies is compared and analyzed.The present results provide important support for designing the interface structure between SSs and PiF to achieve higher efficiency and higher saturation threshold for warm white light.
基金Financial supports from the National Natural Science Foundation of China(No.22209075)the Natural Science Foundation of Chongqing(No.2022NSCQ-MSX4268)+1 种基金the Postdoctoral Innovation Talents Support Plan of Chongqing(No.CQBX2021012)the Scientific Research Project of Fujian Provincial Department of Education(No.JAT220530)are acknowledged.
文摘To meet the growing demand for wearable smart electronic devices,the development of flexible lithium-ion batteries(LIBs)is essential.Silicon is an ideal candidate for the anode material of flexible lithium-ion batteries due to its high specific capacity,low working potential,and earth abundance.The largest challenge in developing a flexible silicon anode is how to maintain structural integrity and ensure stable electrochemical reactions during external deformation.In this work,we propose a novel design for fabricating core–shell electrodes based on a copper nanowire(CuNW)array core and magnetron sputtered Si/C shell.The nanowire array structure has characteristics of bending under longitudinal stress and twisting under transverse stress,which helps to maintain the mechanical stability of the structure during electrode bending and cycling.The low-temperature annealing generates a small amount of Cu3Si alloy,which enhances the connection strength between Si and the conductive network and solves the poor conductivity problem of Si,which is known as a semiconductor material.This unique configuration design of CuNW@Si@C-400℃ leads to stable long cycle performance of 1109 mAh∙g^(-1) after 1000 cycles and excellent rate performance of 500 mAh∙g^(-1) at a current density of 10 A∙g^(-1).Furthermore,the CuNW@Si@C-400℃||LiFePO_(4)(LFP)full battery demonstrates excellent flexibility,with a capacity retention of more than 96%after 100 bends.This study provides a promising strategy for the development of flexible lithium-ion batteries.
基金Project supported by the National Natural Science Foundation of China(No.61464002)the Grand Science and Technology Special Project in Guizhou Province of China(No.[2015]6006)the Ministry of Education Open Foundation for Semiconductor Power Device Reliability(No.010201)
文摘Single event irradiation-hardened power MOSFET is the most important device for DC/DC converter in space environment application. Single event gate rupture （SEGR） and single event burnout （SEB）, which will degrade the running safety and reliability of spacecraft, are the two typical failure modes in power MOSFETs. In this paper, based on recombination mechanism of interface between oxide and silicon, a novel hardened power MOS- FETs structure for SEGR and SEB is proposed. The structure comprises double stagger partial silicon-on-insulator （DSPSOI） layers. Results show that the safety operation area （SOA） of a 130 V N-channel power MOSFET in single event irradiation environment is enhanced by up to 50% when the linear-energy-transfer value of heavy ion is a constant of 98 MeV-cm2/mg in the whole incident track, and the other parameters are almost maintained at the same value. Thus this novel structure can be widely used in designing single event irradiation-hardened power MOSFETs.
基金supported by the National Natural Science Foundation of China(No.61176071)the Doctoral Fund of Ministry of Education of China(No.20111103120016)the Science and Technology Program of State Grid Corporation of China(No.SGRI-WD-71-13-006)
文摘The addition of a buffer layer can improve the device＇s secondary breakdown voltage, thus, improving the single event burnout （SEB） threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an op- timized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer ~ayer. So the linear buffer layer is more advantageous to improving the device＇s SEB performance.
