Reliability Evaluation of Plessey Low Noise Gallium Arsenide Field Effect Transistors

An evaluation programme carried out on the Plessey Low Noise Gallium Arsenide Field Effect Transistors GAT 5 and GAT 6 is described. The programme conformed to the European Space Agency (ESA) requirements defined in QRC50G, Guidelines for the Selection, Evaluation, Screening and Lot Acceptance of Non-Standard Electronic, Electric and Electromechanical Parts. The purpose of the evaluation programme was to establish the reliability of the devices and qualify them for use in Space applications. Results obtained for the various tests are given together with an analysis of the data and failure analysis performed on device failures. An MTTF of 3 × 107 hours was obtained for the GAT 5 manufactured with aluminium gate metallisation and gold wire bonding. An MTTF of 1 × 108 hours was obtained for the GAT 6 which used titanium/aluminium gate metallisation and aluminium wire bonding to the gate pads.