A thermal model of double‐drift IMPATT diodes on diamond heat sinks has been developed. The thermal model approximates the temperature‐dependent thermal conductivities of Si and diamond (Type II) by means of simple empirical formulae. The application of the thermal model to three IMPATT diode lots indicates that under life test, junction temperatures are greater than 700°C, and that the metal/Si interface temperatures exceed 500°C. An explanation of the failure mechanism is presented. Designs that result in a lower junction temperature are proposed.
A novel technique has been developed to measure temperatures with a spatial resolution less than 10 μm. This method uses the temperature-sensitive time decay fluorescence of a phosphor as a surface sensor. The spatial resolution is obtained by using an electron beam to excite individual phosphor grains deposited on the surface of interest. The phosphor selected for its dynamic range and chemical stability is the inorganic compound magnesium fluorogermanate activated with manganese. The time decay constant of its fluorescence decreases monotonically with temperature between −200 °C to 450 °C. This method was verified on a cross-sectioned Zener diode. A description of the technique and a temperature map of the sectioned area of an operating diode are presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.