O'Mahony, D; Duane, R; Campagno, T; Lewis, L; Cordero, N; Maaskant, P; Waldron, F; Corbett, B

2011

January

Microelectronics Reliability

Thermal stability of SiC Schottky diode anode and cathode metalisations after 1000 h at 350 degrees C

Published

()

OHMIC CONTACTS DEVICES RELIABILITY TECHNOLOGY EVOLUTION

51

904

908

The thermal stability of two commercially available silicon carbide Schottky diode types has been evaluated following a 1000 h non-biased storage test under vacuum at 350 degrees C. The Ti-based Schottky (Anode) contact shows excellent stability over the duration of the test with less than 5% change in either extracted Schottky barrier height or ideality values. The Al die attach metalisation on the anode also shows no evidence of degradation after the test. However, a considerable change in series resistance was observed for both diode types, with up to a factor of 100 measured for one of the diodes. The primary early failure mode is related to degradation of the NiAg Ohmic (cathode) die attach metalisation. Demixing of the NiAg alloy, leading to Ag agglomeration is proposed to be the underlying degradation mechanism involved resulting in delamination of the die attach metalisation and the corresponding series resistance increase. (C) 2011 Elsevier Ltd. All rights reserved.

DOI 10.1016/j.microrel.2010.12.008