Investigations on the effect of contacts on p-type CdTe DLTS-measurements

DLTS-Measurements are an important tool in investigating the defect structure within a Schottky barrier. In polar compound semiconductors like CdTe it cannot be ruled out that the original defect structure of the semiconductor material is changed by the contact formation process. We report for the first time on influences of processes both of the surface pretreatment and of the deposition of contact metals on the results of deep level transient spectroscopy. We report as well on the influence of the ohmic contact on the measured level parameters. We are able to divide the determined defect levels in surface relevant and bulk relevant types.