Comparative thermal characterizations of GaAs and SiC devices

The thermal characteristics of S-band silicon carbide monolithic microwave integrated circuits (MMICs) have been investigated and compared with GaAs devices. It was found that high resolution atomic force thermal microscopy measurements and accurate finite element simulations show a much higher thermal response than that predicted by first order thermal calculations and infrared measurements which give generally better agreement for the GaAs devices. This difference may be explained by an increase in the lateral heat spreading on the device due to the improved thermal conductivity of the silicon carbide. These results can have a major effect on device reliability and packaging.