Comparative calculations of electron transport properties in 6H–SiC using three and five valley models

Steady-state electron properties are investigated in 6H–SiC at various temperatures, using Monte Carlo simulation where the band structure model is a major part when dealing with high fields. The aim of this work is to optimize the number of valleys involved in the simulation program in order to obtain accurate results while improving the calculation efficiency. For high fields, a five valley model was found to be more accurate than a three valley model and as efficient as the full band method though much less computer time-consuming.

Ensemble Monte Carlo analysis of subpicosecond transient electron transport in cubic and hexagonal silicon carbide for high power SiC-MESFET devices

In a comparative framework, an ensemble Monte Carlo was used to elaborate the electron transport characteristics in two different silicon carbide (SiC) polytypes 3C-SiC and 4H-SiC. The simulation was performed using three-valley band structure model. These valleys are spherical and nonparabolic. The aim of this work is to forward the trajectory of 20,000 electrons under high-flied (from 50 kV to 600 kV) and high-temperature (from 200 K to 700 K). We note that this model has already been used in other studies of many Zincblende or Wurtzite semiconductors. The obtained results, compared with results found in many previous studies, show a notable drift velocity overshoot. This last appears in subpicoseconds transient regime and this overshoot is directly attached to the applied electric field and lattice temperature.

Investigation of Time Instability Factors in Ti-SbxTe Based Phase Change Memory

In this paper, the two time instability factors in phase change memory, amorphous resistance drift and spontaneous crystallization process, are studied based on Ti2.75(SbxTe)97.25 and Ti6.85(SbxTe)93.15. The drift coefficients of both components are calculated and compared under room temperature. The reason why the drift coefficient decreases with the Ti concentration increases is discussed based on the band structure model of amorphous phase change materials. And the data retention change trend is also presented. The experiment results and the physical explaination can also be extended to other metallic element doped SbxTe alloy phase change materials.