Modeling of Ionization Phenomena in SiC Diodes
Abstract
We have applied out drift-diffusion simulation to a 6H-SiC We have first looked at the influence of temperature on device performance, in particular concerning the degree of ionization of the deep levels present in the semiconductor. We have detected large variations in the ionization rate by going when the temperature goes from 300 to 800 K. The different behavior of acceptors and donors causes the diode depletion region to grow more rapidly on the n side than on the p one. The peak field increases with temperature, due to the higher level of fixed charge at the junction. In the examined structures, tunneling times our of shallow are in the femtosecond range for sufficiently high fields. Thus tunneling is the dominant ionization mechanism under high bias conditions. We have studied the diode response to a pulsed voltage, finding a significant influence of tunneling processes. None of the effects founds for SiC shows up in Si diodes. There, in fact, donors and acceptors are much shallower, and they result completely ionized under any standard operating condition.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 03, 1998
- Accession Number
- ADA349320
Entities
People
- Paolo Lugli
Organizations
- Sapienza University of Rome