With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been...With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas sensors.However,it is limited by high operating temperature.The current research works are directed towards fabricating high-performance flexible room-temperature(FRT)gas sensors,which are effective in simplifying the structure of MOS-based sensors,reducing power consumption,and expanding the application of portable devices.This article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism,performance,flexibility characteristics,and applications.This review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors,including pristine MOS,noble metal nanoparticles modified MOS,organic polymers modified MOS,carbon-based materials(carbon nanotubes and graphene derivatives)modified MOS,and two-dimensional transition metal dichalcogenides materials modified MOS.The effect of light-illuminated to improve gas sensing performance is further discussed.Furthermore,the applications and future perspectives of FRT gas sensors are also discussed.展开更多
Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in ...Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in structural instability and thus degrade the performance of MOS. Hence, the basic insight into the structural evolutions of low-dimensional MOS is a prerequisite for extensive applications, which unfortunately remains largely unexplored. Herein, we review the recent progress regarding the mechanical deformation mechanisms in MOSs, such as CuO and ZnO nanowires(NWs). We report the phase transformation of CuO NWs resulting from oxygen vacancy migration under compressive stress and the tensile strain-induced phase transition in ZnO NWs. Moreover, the influence of electron beam irradiation on interpreting the mechanical behaviors is discussed.展开更多
Surface passivation with acidic （NH4）2S solution is shown to be effective in improving the interfacial and electrical properties of HfOE/GaSb metal oxide semiconductor devices. Compared with control samples, the sam...Surface passivation with acidic （NH4）2S solution is shown to be effective in improving the interfacial and electrical properties of HfOE/GaSb metal oxide semiconductor devices. Compared with control samples, the samples treated with acidic （NH4）2S solution show great improvements in gate leakage current, frequency dispersion, border trap density, and interface trap density. These improvements are attributed to the enhancing passivation of the substrates, according to analysis from the perspective of chemical mechanism, X-ray photoelectron spectroscopy, and high-resolution cross-sectional transmission electron microscopy.展开更多
The n-type ultrathin fully depleted silicon-on-insulator(FDSOI) metal-oxide-semiconductor field-effect transistors(MOSFETs),with a Hf_(0.5)Zr_(0.5)O_(2) high dielectric permittivity(high-k) dielectric as gate insulato...The n-type ultrathin fully depleted silicon-on-insulator(FDSOI) metal-oxide-semiconductor field-effect transistors(MOSFETs),with a Hf_(0.5)Zr_(0.5)O_(2) high dielectric permittivity(high-k) dielectric as gate insulator,were fabricated.The total ionizing dose effects were investigated,and an X-ray radiation dose up to 1500 krad(Si) was applied for both long-and short-channel devices.The short-channel devices(0.025-0.100 μm) exhibited less irradiation sensitivity compared with the long-channel devices(0.35-16 μm),leading to a 71% reduction in the irradiation-induced drain current growth and a 26% decrease in the shift of the threshold voltage.It was experimentally demonstrated that the OFF mode is the worst case among the three working conditions(OFF,ON and A110) for short-channel devices.Also,the determined effective electron mobility was enhanced by 38% after X-ray irradiation,attributed to the different compensations for charges triggered by radiation between the highk dielectric and buried oxide.By extracting the carrier mobility,gate length modulation,and source/drain(S/D)parasitic resistance,the degradation mechanism on X-ray irradiation was revealed.Finally,the split capacitance-voltage measurements were used to validate the analysis.展开更多
This work investigated the potential of metal oxide semiconductor(MOS)gas sensors for environmental monitoring of methane.Calibrations were performed under controlled conditions in the lab,and under semi-controlled co...This work investigated the potential of metal oxide semiconductor(MOS)gas sensors for environmental monitoring of methane.Calibrations were performed under controlled conditions in the lab,and under semi-controlled conditions in the field,using a modified head space chamber set-up.Concentrations up to±300 ppm methane were tested.The relationship between sensor conductance and methane concentrations could be very well described using principles from adsorption theory.The adjustable parameters were background conductance G_(0),a sensitivity constant S and a non-ideality coefficient n,where n has a non-rational value between 0 and 1.Sensor behaviour was very different in dry air than in humid air,with the background conductance increasing approximately tenfold and sensitivity decreasing between 20 fold and 80 fold,while the non-ideality coefficient increased from±0.4 to±0.6.Nevertheless,at high methane concentrations comparable conductance values were recorded in dry and humid air.The standard deviation of predicted values was 1.6μS.for the least well described dataset.Using the corresponding calibration curve,a detection limit of 11 ppm is calculated for humid ambient air.This values suggests that MOS sensor are adequately sensitive to be used for methane detection in an agricultural context.展开更多
As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and...As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and heavy carbon footprint.Alternatively,photoelectrocatalytic(PEC)production of H2O2 has shown great promises to make H2O2 a renewable fuel to store solar energy.Transition‐metal‐oxide(TMO)semiconductor based photoelectrocatalysts are among the most promising candidates for PEC H2O2 production.In this work,the fundamentals of H2O2 synthesis through PEC process are briefly introduced,followed by the state‐of‐the‐art of TMO semiconductor based photoelectrocatalysts for PEC production H2O2.Then,the progress on H2O2 fuel cells from on‐site PEC production is presented.Furthermore,the challenges and future perspectives of PEC H2O2 production are discussed.This review aims to provide inspiration for the PEC production of H2O2 as a renewable solar fuel.展开更多
The effect of nitric oxide（NO） annealing on charge traps in the oxide insulator and transition layer in n-type4H–Si C metal–oxide–semiconductor（MOS） devices has been investigated using the time-dependent bias s...The effect of nitric oxide（NO） annealing on charge traps in the oxide insulator and transition layer in n-type4H–Si C metal–oxide–semiconductor（MOS） devices has been investigated using the time-dependent bias stress（TDBS）,capacitance–voltage（C–V）,and secondary ion mass spectroscopy（SIMS）.It is revealed that two main categories of charge traps,near interface oxide traps（Nniot） and oxide traps（Not）,have different responses to the TDBS and C–V characteristics in NO-annealed and Ar-annealed samples.The Nniotare mainly responsible for the hysteresis occurring in the bidirectional C–V characteristics,which are very close to the semiconductor interface and can readily exchange charges with the inner semiconductor.However,Not is mainly responsible for the TDBS induced C–V shifts.Electrons tunneling into the Not are hardly released quickly when suffering TDBS,resulting in the problem of the threshold voltage stability.Compared with the Ar-annealed sample,Nniotcan be significantly suppressed by the NO annealing,but there is little improvement of Not.SIMS results demonstrate that the Nniotare distributed within the transition layer,which correlated with the existence of the excess silicon.During the NO annealing process,the excess Si atoms incorporate into nitrogen in the transition layer,allowing better relaxation of the interface strain and effectively reducing the width of the transition layer and the density of Nniot.展开更多
In this paper the trapping effects in Al2O3/In0.17Al0.83N/GaN MOS-HEMT（here, HEMT stands for high electron mobility transistor） are investigated by frequency-dependent capacitance and conductance analysis. The trap ...In this paper the trapping effects in Al2O3/In0.17Al0.83N/GaN MOS-HEMT（here, HEMT stands for high electron mobility transistor） are investigated by frequency-dependent capacitance and conductance analysis. The trap states are found at both the Al2O3/In AlN and InAlN/GaN interface. Trap states in InAlN/GaN heterostructure are determined to have mixed de-trapping mechanisms, emission, and tunneling. Part of the electrons captured in the trap states are likely to tunnel into the two-dimensional electron gas（2DEG） channel under serious band bending and stronger electric field peak caused by high Al content in the In AlN barrier, which explains the opposite voltage dependence of time constant and relation between the time constant and energy of the trap states.展开更多
Creating gas sensors that are highly selective and function at low temperatures based on semiconductor metal oxides(SMOs)is considered a difficult endeavor,and these sensors are extensively applied in medical diagnosi...Creating gas sensors that are highly selective and function at low temperatures based on semiconductor metal oxides(SMOs)is considered a difficult endeavor,and these sensors are extensively applied in medical diagnosis,industrial manufacturing,and in spacecraft within the aerospace sector.This review article delves into the emerging horizons of chemiresistive gas sensing,particularly focusing on the synergy between polyoxometalates(POMs)and block copolymers in self-assembly for the construction of ordered mesoporous metal oxides(MMOs).It highlights the advancements in gas sensing technology,emphasizing the role of POMs as precursors for MMOs,which offer high sensitivity and selectivity due to their unique physicochemical properties.The review covers various synthetic strategies and their impact on sensor performance,including low-temperature operation,high sensitivity,and selectivity towards specific gases.It also underscores the importance of nanostructure control,heteroatom doping,and the integration of noble metal catalysts in enhancing sensor capabilities.The article concludes with future research directions,suggesting the exploration of a broader range of detectable compounds and the integration of these materials into practical devices for real-world applications.展开更多
Pulsed metal organic chemical vapor deposition was employed to grow nearly polarization matched InAlGaN/GaN heterostructures.A relatively low sheet carrier density of 1.8×10^(12)cm^(-2),together with a high elect...Pulsed metal organic chemical vapor deposition was employed to grow nearly polarization matched InAlGaN/GaN heterostructures.A relatively low sheet carrier density of 1.8×10^(12)cm^(-2),together with a high electron mobility of 1229.5 cm^2/V·s,was obtained for the prepared heterostructures.The surface morphology of the heterostructures was also significantly improved,i.e.,with a root mean square roughness of 0.29 nm in a 2μm×2μm scan area.In addition to the improved properties,the enhancement-mode metal–oxide–semiconductor high electron mobility transistors(MOSHEMTs)processed on the heterostructures not only exhibited a high threshold voltage(VTH)of 3.1 V,but also demonstrated a significantly enhanced drain output current density of 669 m A/mm.These values probably represent the largest values obtained from the InAlGaN based enhancement-mode devices to the best of our knowledge.This study strongly indicates that the InAlGaN/GaN heterostructures grown by pulsed metal organic chemical vapor deposition could be promising for the applications of novel nitride-based electronic devices.展开更多
Two-dimensional(2D)transition metal dichalcogenides(TMDs),which allow atomic-scale manipulation,have supe-rior electrical and optical properties that challenge the limits of traditional bulk semiconductors like silico...Two-dimensional(2D)transition metal dichalcogenides(TMDs),which allow atomic-scale manipulation,have supe-rior electrical and optical properties that challenge the limits of traditional bulk semiconductors like silicon^([1,2]).As a repre-sentative TMD and a promising 2D channel material for high-performance,scalable p-type transistors,tungsten diselenide(WSe_(2))has attracted considerable academic and industrial interest for its potential in advanced complementary metal−oxide−semiconductor(CMOS)logic technology and in extending Moore’s Law^([3−7]).展开更多
This paper gives a statistical view about important contributions and advances on semiconductor metal oxide （SMO） compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas （...This paper gives a statistical view about important contributions and advances on semiconductor metal oxide （SMO） compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas （LPG）, H2S, NH3, CO2, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e., they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.展开更多
A 37. 5 MHz differential complementary metal oxide semiconductor （CMOS） crystal oscillator with low power and low phase noise for the radio frequency tuner of digital radio broadcasting digital radio mondiale （DRAM...A 37. 5 MHz differential complementary metal oxide semiconductor （CMOS） crystal oscillator with low power and low phase noise for the radio frequency tuner of digital radio broadcasting digital radio mondiale （DRAM） and digital audio broadcasting （DAB） systems is realized and characterized. The conventional cross-coupled n-type metal oxide semiconductor （NMOS） transistors are replaced by p-type metal oxide semiconductor （PMOS） transistors to decrease the phase noise in the core part of the crystal oscillator. A symmetry structure of the current mirror is adopted to increase the stability of direct current. The amplitude detecting circuit made up of a single- stage CMOS operational transconductance amplifier （OTA） and a simple amplitude detector is used to improve the current accuracy of the output signals. The chip is fabricated in a 0. 18- pxn CMOS process, and the total chip size is 0. 35 mm x 0. 3 mm. Under a supply voltage of 1.8 V, the measured power consumption is 3.6 mW including the output buffer for 50 testing loads. The proposed crystal oscillator exhibits a low phase noise of - 134. 7 dBc/Hz at 1-kHz offset from the center frequency of 37. 5 MHz.展开更多
A low noise, high conversion gain down-conversion mixer for WLAN 802.11a applications, which adopts the high intermediate frequency （IF） topology, is presented. The input radio frequency （RF）band, local oscillator...A low noise, high conversion gain down-conversion mixer for WLAN 802.11a applications, which adopts the high intermediate frequency （IF） topology, is presented. The input radio frequency （RF）band, local oscillator（LO）frequency band and output IF are 5.15 to 5.35, 4.15 to 4.35 and 1 GHz, respectively. Source resistive degeneration technique and pseudo-differential Gilbert topology are used to achieve high linearity, and, current bleeding technique and LC resonant loads are used to acquire a low noise figure. In addition, the mixer adopts a common-source transistor pair cross-stacked with a source follow pair（CSSF）circuit as an output buffer to enhance the mixer＇s conversion gain but not deteriorate the other performances. The mixer is implemented in 0.18 μm RF CMOS（complementary metal oxide semiconductor transistor）technology and the chip area of the mixer including all bonding pads is 580 μm×1 185 μm. The measured results show that under a 1.8 V supply, the conversion gain is 10.1 dB; the input 1 dB compression point and the input-referred third-order intercept point are-3.5 and 5.3 dBm, respectively; the single side band （SSB）noise figure （NF）is 8.65 dB, and the core current consumption is 3.8 mA.展开更多
Metal oxide semiconductors(MOSs) are ideal sensing materials for detecting volatile organic compounds due to their low cost, diversity, high stability, and ease of production. However, it remains a grand challenge to ...Metal oxide semiconductors(MOSs) are ideal sensing materials for detecting volatile organic compounds due to their low cost, diversity, high stability, and ease of production. However, it remains a grand challenge to develop the MOSs-based gas sensors for sensing isopropanol with desired performance via a simple, effective,and controllable method. Herein, we reported the preparation of the Al-doped Zn O(AZO)/WO_(3) heterostructure films by directly depositing the AZO coating onto the WO_(3) coating using a strategy of magnetron sputtering. The AZO/WO_(3) heterostructure films were constructed by numbers of irregular nanoparticles that were interconnected with each other. The AZO/WO_(3) heterostructure films-based gas sensors exhibited excellent isopropanolsensing performance with high response, promising selectivity, low detection limit, fast response rate, wide detection range, and ideal reproducibility. The promising isopropanol-sensing performance of the AZO/WO_(3) heterostructure films arises mainly from their high uniformity, unique microstructures with high surface roughness,and the construction of the heterostructure between the AZO and WO_(3) coatings. This work provides a versatile approach to prepare the MOSs-based heterostructure films for assembling the gas sensors.展开更多
Metal oxide ion-gated transistors(MOIGTs)have garnered significant attention within the sensing domain due to their potential for achieving heightened sensitivity while consuming minimal energy across diverse scenario...Metal oxide ion-gated transistors(MOIGTs)have garnered significant attention within the sensing domain due to their potential for achieving heightened sensitivity while consuming minimal energy across diverse scenarios.By harnessing the advantageous combination of metal oxides'high carrier mobility and facile surface customization,coupled with the potent signal amplification capabilities of ion-gated transistors,MOIGTs offer a promising avenue for discerning biomolecules,overseeing chemical reactions,p H levels,as well as facilitating gas or light determination.Over the past few decades,the MOIGT field has made remarkable strides in refining device physics,enhancing material properties,showcasing robust sensing capabilities,and broadening its application spectrum.These advancements have simultaneously unveiled new challenges and opportunities,necessitating interdisciplinary expertise to fully unlock the commercial potential of MOIGTs.In this comprehensive review,we offer a snapshot of this swiftly evolving technology,delve into its current applications,and provide insightful recommendations for future directions in the coming decade.展开更多
s:A detailed description of relaxation spectroscopy technique under direct tunneling stress is given.A double peak phenomena by applied relaxation spectroscopy on ultra thin (<3nm) gate oxide is found.It suggests ...s:A detailed description of relaxation spectroscopy technique under direct tunneling stress is given.A double peak phenomena by applied relaxation spectroscopy on ultra thin (<3nm) gate oxide is found.It suggests that two kinds of traps exist in the degradation of gate oxide.It is also observed that both the trap density and the generation/capture cross section of oxide trap and interface trap are smaller in ultra thin gate oxide (<3nm) under DT stress than those in the thicker oxide (>4nm) under FN stress,and the centroid of oxide trap is closer to anode interface than in the center of oxide.展开更多
A simple and new point contact tungsten trioxide （WO3） sensor, which can be prepared by the oxidation of tungsten filaments via in-situ induction heating, likely detects low concentration （ppm level） environmental...A simple and new point contact tungsten trioxide （WO3） sensor, which can be prepared by the oxidation of tungsten filaments via in-situ induction heating, likely detects low concentration （ppm level） environmental pollutants such as NO2. X-ray diffraction （XRD） and field emission scanning electron microscopy （FE-SEM） were applied to characterize the phase and the microstructure of the samples, respec-tively. It was found that the synthesized WO3 films exhibited a monoclinic phase and were composed of hierarchical microcrystals and nanocrystals. The point contact WO3 sensor （W-WO3-W） showed rectifying characteristics and an ideal sensing performance of about 110 C. A single semicircle in Nyquist plots was recorded by electrochemical impedance spectroscopy （EIS） at a relatively low temperature of 150 C but faded away above 200 C, which revealed that the sensing process was governed by a determining factor, i.e., grain boundaries at the contact site.展开更多
With targets of cost reduction per bit and high energy efficiency,5G and beyond call for innovation in the mmWave transmitter architecture and the power amplifier(PA)circuit.To illustrate these points,this paper first...With targets of cost reduction per bit and high energy efficiency,5G and beyond call for innovation in the mmWave transmitter architecture and the power amplifier(PA)circuit.To illustrate these points,this paper firstly explains the benefits and design implications of the hybrid beamforming structure in terms of the mmWave spectrum characteristics,energy efficiency,data rate,communication capacity,coverage and implementation technology choices.Then after reviewing the techniques to improve the power amplifier(PA)output power and efficiency,the design considerations and test results of 60 GHz and 90 GHz mmWave PAs in bulk complementary metal oxide semiconductor(CMOS)process are shown.展开更多
A 60 GHz phased array system for mm wave frequency in 5G is introduced and a 5 bit digitally controlled phase shifter in 40 nm CMOS technology is presented.In a phased array system,the signal to noise ratio(SNR)of the...A 60 GHz phased array system for mm wave frequency in 5G is introduced and a 5 bit digitally controlled phase shifter in 40 nm CMOS technology is presented.In a phased array system,the signal to noise ratio(SNR)of the receiver is improved with the beaming forming function.Therefore,the communication data rate and distance are improved accordingly.The phase shifter is the key component for achieving the beam forming function,and its resolution and power consumption are also very critical.In the second half of this paper,an analysis of phase shifter is introduced,and a 60 GHz 5 bit digitally controlled phase shifter in 40 nm complementary metal oxide semiconductor(CMOS)technology is presented.In this presented phase shifter,a hybrid structure is implemented for its advantage on lower phase deviation while keeping comparable loss.Meanwhile,this digitally controlled phase shifter is much more compact than other works.For all 32 states,the minimum phase error is 1.5°,and the maximum phase error is 6.8°.The measured insertion loss is-20.9±1 dB including pad loss at 60 GHz and the return loss is more than 10 dB over 57-64 GHz.The total chip size is 0.24 mm^2 with 0 mW DC power consumption.展开更多
基金This work is supported by This work was supported by the National Key R&D Program of China(Nos.2020YFB2008604 and 2021YFB3202500)the National Natural Science Foundation of China(Nos.61874034 and 51861135105)+1 种基金the International Science and Technology Cooperation Program of Shanghai Science and Technology Innovation Action Plan(No.21520713300)Fudan University-CIOMP Joint Fund(E02632Y7H0).
文摘With the rapid development of the Internet of Things,there is a great demand for portable gas sensors.Metal oxide semiconductors(MOS)are one of the most traditional and well-studied gas sensing materials and have been widely used to prepare various commercial gas sensors.However,it is limited by high operating temperature.The current research works are directed towards fabricating high-performance flexible room-temperature(FRT)gas sensors,which are effective in simplifying the structure of MOS-based sensors,reducing power consumption,and expanding the application of portable devices.This article presents the recent research progress of MOS-based FRT gas sensors in terms of sensing mechanism,performance,flexibility characteristics,and applications.This review comprehensively summarizes and discusses five types of MOS-based FRT gas sensors,including pristine MOS,noble metal nanoparticles modified MOS,organic polymers modified MOS,carbon-based materials(carbon nanotubes and graphene derivatives)modified MOS,and two-dimensional transition metal dichalcogenides materials modified MOS.The effect of light-illuminated to improve gas sensing performance is further discussed.Furthermore,the applications and future perspectives of FRT gas sensors are also discussed.
基金supported by the National Natural Science Foundation of China (52071237, 12074290, 51871169, 51671148, 11674251, 51601132, 52101021, and 12104345)the Natural Science Foundation of Jiangsu Province (BK20191187)+2 种基金the Fundamental Research Funds for the Central Universities (2042019kf0190)the Science and Technology Program of Shenzhen (JCYJ20190808150407522)the China Postdoctoral Science Foundation (2019M652685)。
文摘Metal oxide semiconductors(MOSs) are attractive candidates as functional parts and connections in nanodevices.Upon spatial dimensionality reduction, the ubiquitous strain encountered in physical reality may result in structural instability and thus degrade the performance of MOS. Hence, the basic insight into the structural evolutions of low-dimensional MOS is a prerequisite for extensive applications, which unfortunately remains largely unexplored. Herein, we review the recent progress regarding the mechanical deformation mechanisms in MOSs, such as CuO and ZnO nanowires(NWs). We report the phase transformation of CuO NWs resulting from oxygen vacancy migration under compressive stress and the tensile strain-induced phase transition in ZnO NWs. Moreover, the influence of electron beam irradiation on interpreting the mechanical behaviors is discussed.
基金supported by the State Key Development Program for Basic Research of China(Grant No.2011CBA00602)the Major Project of the NationalScience and Technology of China(Grant No.2011ZX02708-002)
文摘Surface passivation with acidic （NH4）2S solution is shown to be effective in improving the interfacial and electrical properties of HfOE/GaSb metal oxide semiconductor devices. Compared with control samples, the samples treated with acidic （NH4）2S solution show great improvements in gate leakage current, frequency dispersion, border trap density, and interface trap density. These improvements are attributed to the enhancing passivation of the substrates, according to analysis from the perspective of chemical mechanism, X-ray photoelectron spectroscopy, and high-resolution cross-sectional transmission electron microscopy.
基金financially supported by the National Natural Science Foundation of China (Nos.61874135,61904194 and 11905287)the National Major Project of Science and Technology of China (No.2017ZX02315001)+1 种基金the Youth Innovation Promotion Association,CAS (No.Y9YQ01R004)the Opening Project of Key Laboratory of Microelectronic Devices & Integrated Technology,Institute of Microelectronics,CAS (No.Y9YS05X002)。
文摘The n-type ultrathin fully depleted silicon-on-insulator(FDSOI) metal-oxide-semiconductor field-effect transistors(MOSFETs),with a Hf_(0.5)Zr_(0.5)O_(2) high dielectric permittivity(high-k) dielectric as gate insulator,were fabricated.The total ionizing dose effects were investigated,and an X-ray radiation dose up to 1500 krad(Si) was applied for both long-and short-channel devices.The short-channel devices(0.025-0.100 μm) exhibited less irradiation sensitivity compared with the long-channel devices(0.35-16 μm),leading to a 71% reduction in the irradiation-induced drain current growth and a 26% decrease in the shift of the threshold voltage.It was experimentally demonstrated that the OFF mode is the worst case among the three working conditions(OFF,ON and A110) for short-channel devices.Also,the determined effective electron mobility was enhanced by 38% after X-ray irradiation,attributed to the different compensations for charges triggered by radiation between the highk dielectric and buried oxide.By extracting the carrier mobility,gate length modulation,and source/drain(S/D)parasitic resistance,the degradation mechanism on X-ray irradiation was revealed.Finally,the split capacitance-voltage measurements were used to validate the analysis.
基金supported by the European Union’s Horizon 2020 research and innovation programme[grant agreement No.825325].
文摘This work investigated the potential of metal oxide semiconductor(MOS)gas sensors for environmental monitoring of methane.Calibrations were performed under controlled conditions in the lab,and under semi-controlled conditions in the field,using a modified head space chamber set-up.Concentrations up to±300 ppm methane were tested.The relationship between sensor conductance and methane concentrations could be very well described using principles from adsorption theory.The adjustable parameters were background conductance G_(0),a sensitivity constant S and a non-ideality coefficient n,where n has a non-rational value between 0 and 1.Sensor behaviour was very different in dry air than in humid air,with the background conductance increasing approximately tenfold and sensitivity decreasing between 20 fold and 80 fold,while the non-ideality coefficient increased from±0.4 to±0.6.Nevertheless,at high methane concentrations comparable conductance values were recorded in dry and humid air.The standard deviation of predicted values was 1.6μS.for the least well described dataset.Using the corresponding calibration curve,a detection limit of 11 ppm is calculated for humid ambient air.This values suggests that MOS sensor are adequately sensitive to be used for methane detection in an agricultural context.
基金support from the Australian Research Council through its DECRA(DE210100930)Discovery Project (DP200101900)+2 种基金Lau-reate Fellowship (FL190100139) schemesfinancial support from Research Donation Generic(2020003431) from the Faculty of EngineeringArchitecture and Information Technology,The University of Queensland
文摘As a kind of valuable chemicals,hydrogen peroxide(H2O2)has aroused growing attention in many fields.However,H2O2 production via traditional anthraquinone process suffers from challenges of large energy consumption and heavy carbon footprint.Alternatively,photoelectrocatalytic(PEC)production of H2O2 has shown great promises to make H2O2 a renewable fuel to store solar energy.Transition‐metal‐oxide(TMO)semiconductor based photoelectrocatalysts are among the most promising candidates for PEC H2O2 production.In this work,the fundamentals of H2O2 synthesis through PEC process are briefly introduced,followed by the state‐of‐the‐art of TMO semiconductor based photoelectrocatalysts for PEC production H2O2.Then,the progress on H2O2 fuel cells from on‐site PEC production is presented.Furthermore,the challenges and future perspectives of PEC H2O2 production are discussed.This review aims to provide inspiration for the PEC production of H2O2 as a renewable solar fuel.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61404098 and 61274079)the Doctoral Fund of Ministry of Education of China(Grant No.20130203120017)+2 种基金the National Key Basic Research Program of China(Grant No.2015CB759600)the National Grid Science&Technology Project,China(Grant No.SGRI-WD-71-14-018)the Key Specific Project in the National Science&Technology Program,China(Grant Nos.2013ZX02305002-002 and 2015CB759600)
文摘The effect of nitric oxide（NO） annealing on charge traps in the oxide insulator and transition layer in n-type4H–Si C metal–oxide–semiconductor（MOS） devices has been investigated using the time-dependent bias stress（TDBS）,capacitance–voltage（C–V）,and secondary ion mass spectroscopy（SIMS）.It is revealed that two main categories of charge traps,near interface oxide traps（Nniot） and oxide traps（Not）,have different responses to the TDBS and C–V characteristics in NO-annealed and Ar-annealed samples.The Nniotare mainly responsible for the hysteresis occurring in the bidirectional C–V characteristics,which are very close to the semiconductor interface and can readily exchange charges with the inner semiconductor.However,Not is mainly responsible for the TDBS induced C–V shifts.Electrons tunneling into the Not are hardly released quickly when suffering TDBS,resulting in the problem of the threshold voltage stability.Compared with the Ar-annealed sample,Nniotcan be significantly suppressed by the NO annealing,but there is little improvement of Not.SIMS results demonstrate that the Nniotare distributed within the transition layer,which correlated with the existence of the excess silicon.During the NO annealing process,the excess Si atoms incorporate into nitrogen in the transition layer,allowing better relaxation of the interface strain and effectively reducing the width of the transition layer and the density of Nniot.
基金Project supported by the Program for National Natural Science Foundation of China(Grant Nos.61404100 and 61306017)
文摘In this paper the trapping effects in Al2O3/In0.17Al0.83N/GaN MOS-HEMT（here, HEMT stands for high electron mobility transistor） are investigated by frequency-dependent capacitance and conductance analysis. The trap states are found at both the Al2O3/In AlN and InAlN/GaN interface. Trap states in InAlN/GaN heterostructure are determined to have mixed de-trapping mechanisms, emission, and tunneling. Part of the electrons captured in the trap states are likely to tunnel into the two-dimensional electron gas（2DEG） channel under serious band bending and stronger electric field peak caused by high Al content in the In AlN barrier, which explains the opposite voltage dependence of time constant and relation between the time constant and energy of the trap states.
基金financial support from the Program for the Development of Science and Technology of Jilin Province(YDZJ202401335ZYTS)the Fundamental Research Funds for the Central Universities
文摘Creating gas sensors that are highly selective and function at low temperatures based on semiconductor metal oxides(SMOs)is considered a difficult endeavor,and these sensors are extensively applied in medical diagnosis,industrial manufacturing,and in spacecraft within the aerospace sector.This review article delves into the emerging horizons of chemiresistive gas sensing,particularly focusing on the synergy between polyoxometalates(POMs)and block copolymers in self-assembly for the construction of ordered mesoporous metal oxides(MMOs).It highlights the advancements in gas sensing technology,emphasizing the role of POMs as precursors for MMOs,which offer high sensitivity and selectivity due to their unique physicochemical properties.The review covers various synthetic strategies and their impact on sensor performance,including low-temperature operation,high sensitivity,and selectivity towards specific gases.It also underscores the importance of nanostructure control,heteroatom doping,and the integration of noble metal catalysts in enhancing sensor capabilities.The article concludes with future research directions,suggesting the exploration of a broader range of detectable compounds and the integration of these materials into practical devices for real-world applications.
基金Project supported by the National Postdoctoral Program for Innovative Talents,China(Grant No.BX201700184)the National Key Research and Development Program of China(Grant Nos.2016YFB0400105 and 2017YFB0403102)
文摘Pulsed metal organic chemical vapor deposition was employed to grow nearly polarization matched InAlGaN/GaN heterostructures.A relatively low sheet carrier density of 1.8×10^(12)cm^(-2),together with a high electron mobility of 1229.5 cm^2/V·s,was obtained for the prepared heterostructures.The surface morphology of the heterostructures was also significantly improved,i.e.,with a root mean square roughness of 0.29 nm in a 2μm×2μm scan area.In addition to the improved properties,the enhancement-mode metal–oxide–semiconductor high electron mobility transistors(MOSHEMTs)processed on the heterostructures not only exhibited a high threshold voltage(VTH)of 3.1 V,but also demonstrated a significantly enhanced drain output current density of 669 m A/mm.These values probably represent the largest values obtained from the InAlGaN based enhancement-mode devices to the best of our knowledge.This study strongly indicates that the InAlGaN/GaN heterostructures grown by pulsed metal organic chemical vapor deposition could be promising for the applications of novel nitride-based electronic devices.
文摘Two-dimensional(2D)transition metal dichalcogenides(TMDs),which allow atomic-scale manipulation,have supe-rior electrical and optical properties that challenge the limits of traditional bulk semiconductors like silicon^([1,2]).As a repre-sentative TMD and a promising 2D channel material for high-performance,scalable p-type transistors,tungsten diselenide(WSe_(2))has attracted considerable academic and industrial interest for its potential in advanced complementary metal−oxide−semiconductor(CMOS)logic technology and in extending Moore’s Law^([3−7]).
文摘This paper gives a statistical view about important contributions and advances on semiconductor metal oxide （SMO） compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas （LPG）, H2S, NH3, CO2, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e., they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.
基金The National Natural Science Foundation of China(No. 61106024)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20090092120012)the Science and Technology Program of South east University (No. KJ2010402)
文摘A 37. 5 MHz differential complementary metal oxide semiconductor （CMOS） crystal oscillator with low power and low phase noise for the radio frequency tuner of digital radio broadcasting digital radio mondiale （DRAM） and digital audio broadcasting （DAB） systems is realized and characterized. The conventional cross-coupled n-type metal oxide semiconductor （NMOS） transistors are replaced by p-type metal oxide semiconductor （PMOS） transistors to decrease the phase noise in the core part of the crystal oscillator. A symmetry structure of the current mirror is adopted to increase the stability of direct current. The amplitude detecting circuit made up of a single- stage CMOS operational transconductance amplifier （OTA） and a simple amplitude detector is used to improve the current accuracy of the output signals. The chip is fabricated in a 0. 18- pxn CMOS process, and the total chip size is 0. 35 mm x 0. 3 mm. Under a supply voltage of 1.8 V, the measured power consumption is 3.6 mW including the output buffer for 50 testing loads. The proposed crystal oscillator exhibits a low phase noise of - 134. 7 dBc/Hz at 1-kHz offset from the center frequency of 37. 5 MHz.
基金The Science and Technology Program of Zhejiang Province (No.2008C16017)
文摘A low noise, high conversion gain down-conversion mixer for WLAN 802.11a applications, which adopts the high intermediate frequency （IF） topology, is presented. The input radio frequency （RF）band, local oscillator（LO）frequency band and output IF are 5.15 to 5.35, 4.15 to 4.35 and 1 GHz, respectively. Source resistive degeneration technique and pseudo-differential Gilbert topology are used to achieve high linearity, and, current bleeding technique and LC resonant loads are used to acquire a low noise figure. In addition, the mixer adopts a common-source transistor pair cross-stacked with a source follow pair（CSSF）circuit as an output buffer to enhance the mixer＇s conversion gain but not deteriorate the other performances. The mixer is implemented in 0.18 μm RF CMOS（complementary metal oxide semiconductor transistor）technology and the chip area of the mixer including all bonding pads is 580 μm×1 185 μm. The measured results show that under a 1.8 V supply, the conversion gain is 10.1 dB; the input 1 dB compression point and the input-referred third-order intercept point are-3.5 and 5.3 dBm, respectively; the single side band （SSB）noise figure （NF）is 8.65 dB, and the core current consumption is 3.8 mA.
基金financially supported by the National Natural Science Foundation of China (Nos.52172094 and 22209105)Shanghai Municipal Natural Science Foundation (No.21ZR1426700)the “Shuguang” Program of Shanghai Education Commission (No.19SG46)。
文摘Metal oxide semiconductors(MOSs) are ideal sensing materials for detecting volatile organic compounds due to their low cost, diversity, high stability, and ease of production. However, it remains a grand challenge to develop the MOSs-based gas sensors for sensing isopropanol with desired performance via a simple, effective,and controllable method. Herein, we reported the preparation of the Al-doped Zn O(AZO)/WO_(3) heterostructure films by directly depositing the AZO coating onto the WO_(3) coating using a strategy of magnetron sputtering. The AZO/WO_(3) heterostructure films were constructed by numbers of irregular nanoparticles that were interconnected with each other. The AZO/WO_(3) heterostructure films-based gas sensors exhibited excellent isopropanolsensing performance with high response, promising selectivity, low detection limit, fast response rate, wide detection range, and ideal reproducibility. The promising isopropanol-sensing performance of the AZO/WO_(3) heterostructure films arises mainly from their high uniformity, unique microstructures with high surface roughness,and the construction of the heterostructure between the AZO and WO_(3) coatings. This work provides a versatile approach to prepare the MOSs-based heterostructure films for assembling the gas sensors.
基金supported by the Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(Grant No.NY221111)the Natural Science Foundation of Jiangsu Province of China(Grant Nos.BK20220397,BK20230359)+2 种基金the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province(Grant Nos.22KJB430038,22KJB510010)the National Natural Science Foundation of China(Grant Nos.62204130,62288102,and62304112)the National Funds for Distinguished Young Scientists(Grant No.61825503)。
文摘Metal oxide ion-gated transistors(MOIGTs)have garnered significant attention within the sensing domain due to their potential for achieving heightened sensitivity while consuming minimal energy across diverse scenarios.By harnessing the advantageous combination of metal oxides'high carrier mobility and facile surface customization,coupled with the potent signal amplification capabilities of ion-gated transistors,MOIGTs offer a promising avenue for discerning biomolecules,overseeing chemical reactions,p H levels,as well as facilitating gas or light determination.Over the past few decades,the MOIGT field has made remarkable strides in refining device physics,enhancing material properties,showcasing robust sensing capabilities,and broadening its application spectrum.These advancements have simultaneously unveiled new challenges and opportunities,necessitating interdisciplinary expertise to fully unlock the commercial potential of MOIGTs.In this comprehensive review,we offer a snapshot of this swiftly evolving technology,delve into its current applications,and provide insightful recommendations for future directions in the coming decade.
文摘s:A detailed description of relaxation spectroscopy technique under direct tunneling stress is given.A double peak phenomena by applied relaxation spectroscopy on ultra thin (<3nm) gate oxide is found.It suggests that two kinds of traps exist in the degradation of gate oxide.It is also observed that both the trap density and the generation/capture cross section of oxide trap and interface trap are smaller in ultra thin gate oxide (<3nm) under DT stress than those in the thicker oxide (>4nm) under FN stress,and the centroid of oxide trap is closer to anode interface than in the center of oxide.
基金supported by the National Natural Science Foundation of China (Nos.NSAF10876017, NSAF10776017, and91023037)
文摘A simple and new point contact tungsten trioxide （WO3） sensor, which can be prepared by the oxidation of tungsten filaments via in-situ induction heating, likely detects low concentration （ppm level） environmental pollutants such as NO2. X-ray diffraction （XRD） and field emission scanning electron microscopy （FE-SEM） were applied to characterize the phase and the microstructure of the samples, respec-tively. It was found that the synthesized WO3 films exhibited a monoclinic phase and were composed of hierarchical microcrystals and nanocrystals. The point contact WO3 sensor （W-WO3-W） showed rectifying characteristics and an ideal sensing performance of about 110 C. A single semicircle in Nyquist plots was recorded by electrochemical impedance spectroscopy （EIS） at a relatively low temperature of 150 C but faded away above 200 C, which revealed that the sensing process was governed by a determining factor, i.e., grain boundaries at the contact site.
基金supported by the National Natural Science Foundations of China (Nos. 61306030, 61674037)the National Key R&D Program of China (Nos.2016YFC0800400, 2018YFE0205900)the National Science and Technology Major Project (No. 2018ZX03001008)
文摘With targets of cost reduction per bit and high energy efficiency,5G and beyond call for innovation in the mmWave transmitter architecture and the power amplifier(PA)circuit.To illustrate these points,this paper firstly explains the benefits and design implications of the hybrid beamforming structure in terms of the mmWave spectrum characteristics,energy efficiency,data rate,communication capacity,coverage and implementation technology choices.Then after reviewing the techniques to improve the power amplifier(PA)output power and efficiency,the design considerations and test results of 60 GHz and 90 GHz mmWave PAs in bulk complementary metal oxide semiconductor(CMOS)process are shown.
基金supported by the National Science Foundation of China (No. 61828401)
文摘A 60 GHz phased array system for mm wave frequency in 5G is introduced and a 5 bit digitally controlled phase shifter in 40 nm CMOS technology is presented.In a phased array system,the signal to noise ratio(SNR)of the receiver is improved with the beaming forming function.Therefore,the communication data rate and distance are improved accordingly.The phase shifter is the key component for achieving the beam forming function,and its resolution and power consumption are also very critical.In the second half of this paper,an analysis of phase shifter is introduced,and a 60 GHz 5 bit digitally controlled phase shifter in 40 nm complementary metal oxide semiconductor(CMOS)technology is presented.In this presented phase shifter,a hybrid structure is implemented for its advantage on lower phase deviation while keeping comparable loss.Meanwhile,this digitally controlled phase shifter is much more compact than other works.For all 32 states,the minimum phase error is 1.5°,and the maximum phase error is 6.8°.The measured insertion loss is-20.9±1 dB including pad loss at 60 GHz and the return loss is more than 10 dB over 57-64 GHz.The total chip size is 0.24 mm^2 with 0 mW DC power consumption.
