Effect of Partial Pressure and Temperature on Properties of Vacuum Deposited Chromium-Gold Thin Films

摘要

Chromium-gold thin films were deposited on alumina substrates over a pressure range of 0.0267 to 13.3 mPa, with substrate temperatures ranging from 313 to 523 exp 0 K. A quadrapole residual gas analyzer was used to record the bell jar gas spectrum before and during each run. Correlation of properties with oxygen and hydrogen partial pressure was observed. Adhesion of the chromium-gold films as determined by a 90-degree pull test of thermocompression bonded lead frames was shown to have a bimodal distribution of very low or high strength dependent on oxygen partial pressure and substrate temperature. A system pressure of 6.67 mPa with a substrate temperature of 473 exp 0 K resulted in the highest pull strengths and acceptable failure modes. (ERA citation 07:022291)