Development of an Extreme High Temperature n-type Ohmic Contact to Silicon CarbideWe report on the initial demonstration of a tungsten-nickel (75:25 at. %) ohmic contact to silicon carbide (SiC) that performed for up to fifteen hours of heat treatment in argon at 1000 C. The transfer length method (TLM) test structure was used to evaluate the contacts. Samples showed consistent ohmic behavior with specific contact resistance values averaging 5 x 10-4 -cm2. The development of this contact metallization should allow silicon carbide devices to operate more reliably at the present maximum operating temperature of 600 C while potentially extending operations to 1000 C. Introduction Silicon Carbide (SiC) is widely recognized as one of the materials of choice for high temperature, harsh environment sensors and electronics due to its ability to survive and continue normal operation in such environments [1]. Sensors and electronics in SiC have been developed that are capable of operating at temperatures of 600 oC. However operating these devices at the upper reliability temperature threshold increases the potential for early degradation. Therefore, it is important to raise the reliability temperature ceiling higher, which would assure increased device reliability when operated at nominal temperature. There are also instances that require devices to operate and survive for prolonged periods of time above 600 oC [2, 3]. This is specifically needed in the area of hypersonic flight where robust sensors are needed to monitor vehicle performance at temperature greater than 1000 C, as well as for use in the thermomechanical characterization of high temperature materials (e.g. ceramic matrix composites). While SiC alone can withstand these temperatures, a major challenge is to develop reliable electrical contacts to the device itself in order to facilitate signal extraction
Document ID
20120000739
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Evans, Laura J. (NASA Glenn Research Center Cleveland, OH, United States)
Okojie, Robert S. (NASA Glenn Research Center Cleveland, OH, United States)
Lukco, Dorothy (ASRC Aerospace Corp. Cleveland, OH, United States)
Date Acquired
August 25, 2013
Publication Date
September 11, 2011
Subject Category
Electronics And Electrical Engineering
Report/Patent Number
E-18063
Meeting Information
Meeting: International Conference on Silicon Carbide and Related Materials (ICSCRM 2011)