Fabrication of In-situ SiC/C Thermocouples by Selective Area Laser Deposition

With the intrinsic nature to process relatively small features, selective area laser deposition (SALD) is a potential technique to fabricate complex shaped macro-components with in-situ high-resolution micro-devices. In this study, SALD was used to deposit in-situ silicon carbide/carbon (SiC/C) thermocouples on alumina and silicon carbide substrates with a C02 laser. Tetramethylsilane (TMS) and acetylene (C2H2) were chosen as precursors for deposition of the silicon carbide and carbon lines respectively. The electromotive force (emf) ofthe deposited thermocouple was measured and found to respond sensitively to temperature variations from room temperature to 800°C. The effect ofthe deposition parameters on the product morphology was also investigated.