Title :
Monte Carlo simulation of impact ionization in SiGe HBTs
Author :
Palestri, P. ; Pacelli, A. ; Mastrapasqua, M. ; Bude, J.D.
Author_Institution :
Agere Syst., Murray Hill, NJ, USA
Abstract :
Measurements and Monte Carlo simulations of impact ionization in the base-collector region of SiGe HBTs are presented. A device with low germanium concentration (graded from 0 to 12%) is considered and no differences are found between the experimental multiplication factor in that device and the corresponding silicon control. Because impact ionization (II) occurs inside the bulk-Si collector, phonon and II scattering rates for bulk silicon can be used in the Monte Carlo simulation, avoiding the need to model the strained SiGe layers. Full-Band Monte Carlo simulations are shown to reproduce the multiplication factors measured in SiGe devices featuring different collector profiles.
Keywords :
Ge-Si alloys; Monte Carlo methods; heterojunction bipolar transistors; impact ionisation; semiconductor device models; semiconductor materials; Monte Carlo simulation; SiGe; SiGe heterojunction bipolar transistor; impact ionization; multiplication factor; phonon scattering; Associate members; Cutoff frequency; Doping; Germanium silicon alloys; Heterojunction bipolar transistors; Impact ionization; Phonons; Scattering; Silicon germanium; Voltage;
Journal_Title :
Electron Device Letters, IEEE
