Title :
Some observations on the failure locus of npn transistors and its improvement using graded collector structures
Author :
Humphreys, M.J. ; Nuttall, K.I.
Author_Institution :
University of Liverpool, Department of Electrical Engineering and Electronics, Liverpool, UK
fDate :
8/1/1988 12:00:00 AM
Abstract :
An experimental study of the mechanisms that determine the second breakdown locus of bipolar transistors has been made and supported by a ID computer analysis. The work demonstrates the important contribution towards device ruggedness made by current gain reduction at high current densities and identifies a triggering mechanism linked to current gain restoration when high multiplication levels are present. In addition, the substantial beneficial effect on the resistance to electronically induced second breakdown of incorporating an impurity concentration gradient within the collector has been demonstrated.
Keywords :
bipolar transistors; electric breakdown of solids; failure analysis; semiconductor device models; 1D computer analysis; bipolar transistors; current gain reduction; current gain restoration; electronically induced second breakdown; failure locus; graded collector structures; high current densities; high multiplication levels; impurity concentration gradient; modelling; n-p-n type; second breakdown locus; triggering mechanism;
Journal_Title :
Solid-State and Electron Devices, IEE Proceedings I
DOI :
10.1049/ip-i-1.1988.0015
