Research Toward a Physics of Aging of Silicon P-N Junctions

As part of the Electronic Component Reliability Center at Battelle Memorial Institute an experimental program has been initiated, the goal of which is to develop an approach to reliability prediction based on an understanding of the physical processes responsible for degradation of performance characteristics of electronic component parts. A modification of the Eyring rate equation, accounting for the effects of nonthermal as well as thermal stresses, is used as the mathematical model. The part type used in the experimental program is the ZJ 218-M silicon controlled avalanche rectifier. Nominally identical devices are subjected to various levels of temperature and electric field (dc reverse bias across the p_n junction) and time rates of change of electrical parameters are determined. As sufficient data become available, the constants of the Eyring equation will be determined and its utility as a prediction mechanism will be evaluated. At the same time, an analytical program is being carried out to relate the observed electrical parameters to causitive physical mechanisms. Thus, the constants of the Eyring equation are given meaning in terms of activation energies and frequency factors associated with the physical mechanisms responsible for the deterioration or aging of observable electrical characteristics.