Title :
Anomalies in the output conductance of SiGe HBTs
Author :
Rein, H.-M. ; Friedrich, M.
Author_Institution :
Ruhr-Univ., Bochum, Germany
Abstract :
It is shown that the usual analytical modelling of the output conductance y/sub 22/ of SiGe HBTs can lead to drastic errors. This especially holds for high doping concentration in the base (usually correlated with high Ge content in the base and low-concentration emitter). However, if the analytical relations for y/sub 22/ are derived from a generalized version of the "Integral Charge Control Relation" (GICCR), a good agreement with the "exact" device simulation results is obtained. This is because now the (weighted) minority charge in the collector as well as an effective voltage drop across the low-concentration emitter are taken into account, which can become of dominating influence.<>
Keywords :
Ge-Si alloys; doping profiles; electric admittance; heterojunction bipolar transistors; semiconductor device models; semiconductor doping; semiconductor materials; HBTs; SiGe; analytical modelling; device simulation; doping concentration; integral charge control relation; low-concentration emitter; minority charge; output conductance; voltage drop; Analytical models; Current density; Doping profiles; Germanium silicon alloys; Heterojunction bipolar transistors; Niobium; Semiconductor process modeling; Silicon germanium; Tellurium; Voltage;
Conference_Titel :
Electron Devices Meeting, 1994. IEDM '94. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-2111-1
DOI :
10.1109/IEDM.1994.383283
