RELIABILITY LIFE-TESTING AND FAILURE-ANALYSIS OF GAAS MONOLITHIC KU-BAND DRIVER AMPLIFIERS

Gallium-arsenide monolithic microwave integrated-circuit (MMIC) Ku-ban d driver amplifiers were life tested under accelerated high temperatur e, DC, and RF, conditions until failure. These MMIC are used in variou s applications such as radar and satellite communication systems. The failure mechanisms controlling their reliability must be understood in order to improve the lifetime for these and other applications. This paper discusses the experimental procedures, statistical evaluation of the data, and failure analysis of the devices. To our knowledge this is the first report of RF life testing of dual-gate driver amplifiers. The majority of the devices failed catastrophically due to high drain current, while others failed parametrically due to low output power. Failure analysis indicates that degradation of the Si3N4 dielectric la yer to be the main failure mechanism in these MMIC. Statistical analys is revealed an activation energy of 0.87 eV and a median lifetime of 5 .8.10(4) hours at 140 degrees C channel temperature, which is consiste nt with surface-phenomena failure mechanisms.