Title :
Modeling the temperature-dependent Early voltage of a silicon germanium heterojunction bipolar transistor
Author :
Wartenberg, Scott A. ; Westgate, Charles R.
Author_Institution :
Hewlett-Packard Co., Newark, CA, USA
fDate :
6/1/1999 12:00:00 AM
Abstract :
This paper compares the temperature-dependent Early voltage of a silicon germanium heterojunction bipolar transistor (HBT) to that of a silicon bipolar junction transistor (BJT) fabricated with identical geometry. Derived is an isothermal expression for the forward Early voltage specifically suited to the base composition of a SiGe HBT. The expression includes two fit factors, one for the Si1-xGex alloy and the other for the nonuniform doping density. The fit factors are functions of the device temperature and are determined through pulsed bias measurements
Keywords :
Ge-Si alloys; doping profiles; heterojunction bipolar transistors; semiconductor device models; semiconductor materials; Si1-xGex alloy; SiGe; SiGe HBT; device temperature; fit factors; forward Early voltage; heterojunction bipolar transistor; isothermal expression; modeling; nonuniform doping density; pulsed bias measurements; temperature-dependent Early voltage; Doping; Geometry; Germanium alloys; Germanium silicon alloys; Heterojunction bipolar transistors; Isothermal processes; Pulse measurements; Silicon alloys; Silicon germanium; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
