This manual gives usage information for the Charon semiconductor device simulator. Charon was developed to meet the modeling needs of Sandia National Laboratories and to improve on the capabilities of the commercial TCAD simulators; in particular, the additional capabilities are running very large simulations on parallel computers and modeling displacement damage and other radiation effects in significant detail. The parallel capabilities are based around the MPI interface which allows the code to be ported to a large number of parallel systems, including linux clusters and proprietary “big iron” systems found at the national laboratories and in large industrial settings.
This manual gives usage information for the Charon semiconductor device simulator. Charon was developed to meet the modeling needs of Sandia National Laboratories and to improve on the capabilities of the commercial TCAD simulators; in particular, the additional capabilities are running very large simulations on parallel computers and modeling displacement damage and other radiation effects in significant detail. The parallel capabilities are based around the MPI interface which allows the code to be ported to a large number of parallel systems, including linux clusters and proprietary "big iron" systems found at the national laboratories and in large industrial settings.
We present a comprehensive physics investigation of electrothermal effects in III-V heterojunction bipolar transistors (HBTs) via extensive Technology Computer Aided Design (TCAD) simulation and modeling. We show for the first time that the negative differential resistances of the common-emitter output responses in InGaP/GaAs HBTs are caused not only by the well-known carrier mobility reduction, but more importantly also by the increased base-To-emitter hole back injection, as the device temperature increases from self-heating. Both self-heating and impact ionization can cause fly-backs in the output responses under constant base-emitter voltages. We find that the fly-back behavior is due to competing processes of carrier recombination and self-heating or impact ionization induced carrier generation. These findings will allow us to understand and potentially improve the safe operating areas and circuit compact models of InGaP/GaAs HBTs.
We present a comprehensive physics investigation of electrothermal effects in III-V heterojunction bipolar transistors (HBTs) via extensive Technology Computer Aided Design (TCAD) simulation and modeling. We show for the first time that the negative differential resistances of the common-emitter output responses in InGaP/GaAs HBTs are caused not only by the well-known carrier mobility reduction, but more importantly also by the increased base-To-emitter hole back injection, as the device temperature increases from self-heating. Both self-heating and impact ionization can cause fly-backs in the output responses under constant base-emitter voltages. We find that the fly-back behavior is due to competing processes of carrier recombination and self-heating or impact ionization induced carrier generation. These findings will allow us to understand and potentially improve the safe operating areas and circuit compact models of InGaP/GaAs HBTs.
We present an analytic band-to-trap tunneling model developed using the open boundary scattering approach. The new model explicitly includes the effect of heterojunction band offset, in addition to the well known electric field effect. Its analytic form enables straightforward implementation into TCAD device and circuit simulators. The model is capable of simulating both electric field and band offset enhanced carrier recombination due to the band-to-trap tunneling in the depletion region near a heterojunction. Simulation results of an InGaP/GaAs heterojunction bipolar transistor reveal that the proposed model predicts significantly increased base currents, because the hole-to-trap tunneling from the base to the emitter is greatly enhanced by the emitter base heterojunction band offset. The results compare favorably with experimental observations. The developed method can be applied to all one dimensional potentials which can be approximated to a good degree such that the approximated potentials lead to piecewise analytic wave functions with open boundary conditions.
We present an analytic band-to-trap tunneling model developed using the open boundary scattering approach. The new model explicitly includes the effect of heterojunction band offset, in addition to the well known electric field effect. Its analytic form enables straightforward implementation into TCAD device and circuit simulators. The model is capable of simulating both electric field and band offset enhanced carrier recombination due to the band-to-trap tunneling in the depletion region near a heterojunction. Simulation results of an InGaP/GaAs heterojunction bipolar transistor reveal that the proposed model predicts significantly increased base currents, because the hole-to-trap tunneling from the base to the emitter is greatly enhanced by the emitter base heterojunction band offset. The results compare favorably with experimental observations. The developed method can be applied to all one dimensional potentials which can be approximated to a good degree such that the approximated potentials lead to piecewise analytic wave functions with open boundary conditions.