Integrated Circuit Characteristics at 260°C for Aircraft Engine-Control Applications

Extensive characterizations of discrete devices and integrated circuits are reported over the temperature range from room temperature to 250°C and 300°C. These are the initial results of a Navy program for the evaluation and design of solid-state electronics to be operated uncooled in aircraft-engine control applications. Based on these results and results from earlier investigations, discrete semiconductor devices of essentially all generic types function with usable characteristics at junction temperatures up to at least 300°C. First-order device parameter changes result from increased leakage, reduced mobility, and increased resistivity. Both analog and digital integrated circuits were found to exhibit dc as well as useful dynamic characteristics up to temperatures near 250°C. Bipolar circuits with either junction or dielectric isolation degrade due to changes in device operating points and high leakage currents. In analog circuits the temperature capabiity is found to depend critically on the specific circuit design implemented. For a variety of CMOS devices tested a pnpn latchup mechanism between the p-channel transistor and the input protection network limits useful device operation to 260°C. Changes in device and circuit layout are needed to circumvent this failure mode. No fundamental barrier to 300°C functionality of integrated circuits (designed specifically for high-temperature application) was found.