Title :
Energy transport simulation for graded HBT´s: Importance of setting adequate values for transport parameters
Author :
Horio, Kazushige ; Okada, Tadayuki ; Nakatani, Akio
Author_Institution :
Fac. of Syst. Eng., Shibaura Inst. of Technol., Omiya, Japan
fDate :
4/1/1999 12:00:00 AM
Abstract :
An energy transport simulation method for graded AlGaAs/GaAs heterojunction bipolar transistors (HBTs) is presented in which Al composition-, doping density-, and energy-dependences of transport parameters are considered. For several representative Al composition and doping densities, parameters such as electron mobility, energy relaxation time, and upper-valley fraction are evaluated as a function of electron energy by a Monte Carlo method. For the other Al composition, these are determined by a linear interpolation method. Calculated cutoff frequency characteristics and electron velocity profiles are compared with those obtained by using more simplified approaches, demonstrating the importance of giving adequate transport parameters, particularly in analyzing graded band-gap base HBTs
Keywords :
III-V semiconductors; Monte Carlo methods; aluminium compounds; carrier relaxation time; doping profiles; electron mobility; gallium arsenide; heterojunction bipolar transistors; interpolation; semiconductor device models; AlGaAs-GaAs; Monte Carlo method; cutoff frequency characteristics; doping density; electron mobility; energy relaxation time; energy transport simulation; graded HBT; graded band-gap base; linear interpolation method; transport parameters; upper-valley fraction; Doping; Electron mobility; Equations; Gallium arsenide; Heterojunction bipolar transistors; Hydrodynamics; Modeling; Photonic band gap; Power engineering and energy; Systems engineering and theory;
Journal_Title :
Electron Devices, IEEE Transactions on
