A macroscopic model of the magnetoresistance effect in fimited anisotropic semiconductors is built. This model allows us to solve the problem of measurement of physical magnetoresistance components of crystals and fil...A macroscopic model of the magnetoresistance effect in fimited anisotropic semiconductors is built. This model allows us to solve the problem of measurement of physical magnetoresistance components of crystals and films. Based on a unified mathematical model the method is worked out enabling us to measure tensor components of the specific electrical resistance and the relative magnetoresistance of anisotropic semiconductors simultaneously.展开更多
Physics equation-based semiconductor device modeling is accurate but time and money consuming.The need for studying new material and devices is increasing so that there has to be an efficient and accurate device model...Physics equation-based semiconductor device modeling is accurate but time and money consuming.The need for studying new material and devices is increasing so that there has to be an efficient and accurate device modeling method. In this paper, two methods based on multivariate rational regression（MRR） for device modeling are proposed. They are single-pole MRR and double-pole MRR. The two MRR methods are proved to be powerful in nonlinear curve fitting and have good numerical stability. Two methods are compared with OLS and LASSO by fitting the SMIC 40 nm MOS-FET I–V characteristic curve and the normalized mean square error of Single-pole MRR is 3.02 × 10^-8 which is 4 magnitudes less than an ordinary least square. The I–V characteristics of CNT-FET and performance indicators（noise factor, gain, power） of a low noise amplifier are also modeled by using MRR methods. The results show MRR methods are very powerful methods for semiconductor device modeling and have a strong nonlinear curve fitting ability.展开更多
In 2003, Gasser-Hsiao-Li [JDE(2003)] showed that the solution to the bipolar hydrodynamic model for semiconductors(HD model) without doping function time-asymptotically converges to the diffusion wave of the porous me...In 2003, Gasser-Hsiao-Li [JDE(2003)] showed that the solution to the bipolar hydrodynamic model for semiconductors(HD model) without doping function time-asymptotically converges to the diffusion wave of the porous media equation(PME) for the switch-off case. Motivated by the work of Huang-Wu[arXiv:2210.13157], we will confirm that the time-asymptotic expansion proposed by Geng-Huang-Jin-Wu [arXiv:2202.13385] around the diffusion wave is a better asymptotic profile for the HD model in this paper, where we mainly adopt the approximate Green function method and the energy method.展开更多
A complete and accurate surface potential based large-signal model for compound semiconductor HEMTs is presented. A surface potential equation resembling the one used in conventional MOSFET models is achieved. The ana...A complete and accurate surface potential based large-signal model for compound semiconductor HEMTs is presented. A surface potential equation resembling the one used in conventional MOSFET models is achieved. The analytic solutions from the traditional surface potential theory that developed in MOSFET models are inherited. For core model derivation, a novel method is used to realize a direct application of the standard surfacepotentialmodelofMOSFETsforHEMTmodeling,withoutbreakingthemathematicstructure.Thehigh-order derivatives of I–V /C–V remain continuous, making the model suitable for RF large-signal applications. Furthermore, the self-heating effects and the transconductance dispersion are also modelled. The model has been verified through comparison with measured DC IV, Gummel symmetry test, CV, minimum noise figure, small-signal Sparameters up to 66 GHz and single-tone input power sweep at 29 GHz for a 475 m0.1 m InGaAs/GaAs power pHEMT, fabricated at a commercial foundry.展开更多
The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and op...The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and optimization, it will be helpful if this bend loss can be estimated. In this letter, we have derived an analytical formula which can be used to get the bend-loss coefficient by fitting the P-I curves of the devices. It is proved that the formula is successful in estimating the loss coefficients from the P-I curves simulated from a complicated quantum-dot device model. We expect this method could also be valid in estimating bend losses of actual devices.展开更多
This work presents a self-consistent two-dimensional(2-D) simulation method with unified physical models for different operation regimes of charge trapping memory. The simulation carefully takes into consideration the...This work presents a self-consistent two-dimensional(2-D) simulation method with unified physical models for different operation regimes of charge trapping memory. The simulation carefully takes into consideration the tunneling process, charge trapping/de-trapping mechanisms, and 2-D drift-diffusion transport within the storage layer. A string of three memory cells has been simulated and evaluated for different gate stack compositions and temperatures. The simulator is able to describe the charge transport behavior along bitline and tunneling directions under different operations. Good agreement has been made with experimental data,which hence validates the implemented physical models and altogether confirms the simulation as a valuable tool for evaluating the characteristics of three-dimensional NAND flash memory.展开更多
A combined model of the transmission-line laser model （TLLM） and the digital filter approach is developed to simulate the shuttering characteristic of a semiconductor optical amplifier （SOA）, which is inte- grated...A combined model of the transmission-line laser model （TLLM） and the digital filter approach is developed to simulate the shuttering characteristic of a semiconductor optical amplifier （SOA）, which is inte- grated with a sampled grating distributed Bragg reflector （SGDBR） laser, to create a so called SOA-SGDBR laser. The SOA section acts as a shutter to blank the laser output during wavelength switching events. Simulated results show that the turn-on edge of the SOA blanking process will oscillate when the facet reflection of SOA is relatively high. This phenomenon is also observed by experiments.展开更多
文摘A macroscopic model of the magnetoresistance effect in fimited anisotropic semiconductors is built. This model allows us to solve the problem of measurement of physical magnetoresistance components of crystals and films. Based on a unified mathematical model the method is worked out enabling us to measure tensor components of the specific electrical resistance and the relative magnetoresistance of anisotropic semiconductors simultaneously.
文摘Physics equation-based semiconductor device modeling is accurate but time and money consuming.The need for studying new material and devices is increasing so that there has to be an efficient and accurate device modeling method. In this paper, two methods based on multivariate rational regression（MRR） for device modeling are proposed. They are single-pole MRR and double-pole MRR. The two MRR methods are proved to be powerful in nonlinear curve fitting and have good numerical stability. Two methods are compared with OLS and LASSO by fitting the SMIC 40 nm MOS-FET I–V characteristic curve and the normalized mean square error of Single-pole MRR is 3.02 × 10^-8 which is 4 magnitudes less than an ordinary least square. The I–V characteristics of CNT-FET and performance indicators（noise factor, gain, power） of a low noise amplifier are also modeled by using MRR methods. The results show MRR methods are very powerful methods for semiconductor device modeling and have a strong nonlinear curve fitting ability.
基金supported by the National Natural Science Foundation of China(No.12201649)。
文摘In 2003, Gasser-Hsiao-Li [JDE(2003)] showed that the solution to the bipolar hydrodynamic model for semiconductors(HD model) without doping function time-asymptotically converges to the diffusion wave of the porous media equation(PME) for the switch-off case. Motivated by the work of Huang-Wu[arXiv:2210.13157], we will confirm that the time-asymptotic expansion proposed by Geng-Huang-Jin-Wu [arXiv:2202.13385] around the diffusion wave is a better asymptotic profile for the HD model in this paper, where we mainly adopt the approximate Green function method and the energy method.
文摘A complete and accurate surface potential based large-signal model for compound semiconductor HEMTs is presented. A surface potential equation resembling the one used in conventional MOSFET models is achieved. The analytic solutions from the traditional surface potential theory that developed in MOSFET models are inherited. For core model derivation, a novel method is used to realize a direct application of the standard surfacepotentialmodelofMOSFETsforHEMTmodeling,withoutbreakingthemathematicstructure.Thehigh-order derivatives of I–V /C–V remain continuous, making the model suitable for RF large-signal applications. Furthermore, the self-heating effects and the transconductance dispersion are also modelled. The model has been verified through comparison with measured DC IV, Gummel symmetry test, CV, minimum noise figure, small-signal Sparameters up to 66 GHz and single-tone input power sweep at 29 GHz for a 475 m0.1 m InGaAs/GaAs power pHEMT, fabricated at a commercial foundry.
基金Project supported by the National Natural Science Foundation of China(Nos.61274072,60976057)
文摘The optical loss in the bent region is one of the key features for bent-waveguide superluminescent diodes that affects the device performance greatly under some conditions. For the purpose of device fabrication and optimization, it will be helpful if this bend loss can be estimated. In this letter, we have derived an analytical formula which can be used to get the bend-loss coefficient by fitting the P-I curves of the devices. It is proved that the formula is successful in estimating the loss coefficients from the P-I curves simulated from a complicated quantum-dot device model. We expect this method could also be valid in estimating bend losses of actual devices.
基金supported by National Natural Science Foundation of China (Grant No. 91230107)National Basic Research Program of China (973) (Grant No. 2013CBA01604)National High Technology Research and Development Program of China (863) (Grant No. 2015AA016501)
文摘This work presents a self-consistent two-dimensional(2-D) simulation method with unified physical models for different operation regimes of charge trapping memory. The simulation carefully takes into consideration the tunneling process, charge trapping/de-trapping mechanisms, and 2-D drift-diffusion transport within the storage layer. A string of three memory cells has been simulated and evaluated for different gate stack compositions and temperatures. The simulator is able to describe the charge transport behavior along bitline and tunneling directions under different operations. Good agreement has been made with experimental data,which hence validates the implemented physical models and altogether confirms the simulation as a valuable tool for evaluating the characteristics of three-dimensional NAND flash memory.
文摘A combined model of the transmission-line laser model （TLLM） and the digital filter approach is developed to simulate the shuttering characteristic of a semiconductor optical amplifier （SOA）, which is inte- grated with a sampled grating distributed Bragg reflector （SGDBR） laser, to create a so called SOA-SGDBR laser. The SOA section acts as a shutter to blank the laser output during wavelength switching events. Simulated results show that the turn-on edge of the SOA blanking process will oscillate when the facet reflection of SOA is relatively high. This phenomenon is also observed by experiments.
