STUDY OF SOME COMMERCIALLY FABRICATED SEMICONDUCTOR P-N JUNCTION CHARACTERISTICS AND CHARACTERIZATION OF IMPURITY LEVELS PRESENT THEREIN

Abstract

The object of present work has been to study junction properties of some commercially available diodes and transistors. We studied over fifty samples out of which twenty were analyzed in details and are reported here. To study the property of depletion layer of p-n junction we carried out a detail C-V measurement. From this study junction capacitance, depletion width, contact potential etc. have been evaluated. From I-V studies (for forward bias and reverse bias conditions) efficiency factor r? has been estimated for large numbers of diodes. These studies indicate the presence of deep impurity centers in most of the samples. To confirm this we carried out detail investigation to detect defect states, if any, and characterized the defect states whenever found. We have observed the presence many and varied deep states both in Si and Ge. The methods used the states are TSCAP and TSC. for characterizing Ip carrying out the investigation we have to construct fixed and variable temperature system, a constant temperature bath and many electronic circuitry needed for our experiments