Direct observation of localized high current effects in gallium arsenide field effect transistors

High power GaAs integrated circuits operated at elevated temperatures display failure mechanisms which result from the high current densities through the FETs. Evidence of material growths or material accumulations on the drain contacts of high current FETs has been observed after the GaAs substrate material has been removed by chemical etching. These observations support the conclusion that these growths are responsible for end-of-life failures in the high current FETs.