Analysis of metalized 4H-SiC for high-temperature electric weapon applications

Abstract

While silicon (Si) based electronic materials and devices continue to play a dominant role in much of the electrical power industry, novel high-power and high-temperature materials are of great interest to the electric combat systems community. The technical interest in silicon carbide (Sic) is mainly due to its ability to operate at greatly elevated power and temperature (>300° C) levels compared to its Si-based counterpart. High-power and temperature pulsed-power electronics can be exploited by future military combat systems, which could potentially provide significantly improved combat vehicle performance including increased lethality through extending the maximum obtainable gun performance using advanced electric weapon concepts such as electrothermal-chemical (ETC) and electromagnetic (EM) gun technologies.The results of recent experiments conducted at the U.S. Army Research Laboratory (ARL) and theUniversity of Delaware demonstrate the electrical behavior of Sic and metal ohmic-contact layers as a function of thermal stress. These experiments havedetermined that both titanium (Ti) and tantalum (Ta) metalization structures will provide a stable electrical ohmic-contact with n-type Sic at elevated temperatures for short bursts of time that are relevant for pulsed-powered electric weapon technologies. The Ti-Sic structure investigated exhibited a stable current-voltage (I-V) characteristic to as much as 800" C for a 10-min burst, while Ta metalizations provided a stable I-V characteristic on Sic even after a temperature burst of 1,000' C for as long as a 3-min interval.