COMPUTER CONTROLLED SYSTEM FOR TRANSIENT CAPACITANCE MEASUREMENTS OF DEEP LEVELS IN SEMICONDUCTOR.

Abstract

A computer-controlled system was set up for the measurement of deep levels in semiconductors. It has a custom-designed interface card to establish communications between necessary instruments and a personal computer. The card enables the system to have a maximum sampling rate of 20,000 sample/s, much faster than some of the systems used by other workers recently. Comparisons were made between the present system and those of other workers. The system is very versatile as its function is solely determined by software programs; different techniques like DLTS and TSCAP can be used on the same setup by developing different programs. The system was applied to the study of deep traps in Si produced as a result of pulsed-laser irradiation. An electron deep trap level of 0. 22 eV below the conduction band was found.