Reliability Evaluation of GaAs Power FETs.

The devices chosen for this study were the TI MSX802 and laboratory devices, Dexcel 3615A-P100F, MSC 88002, and NEC 868196. All are hermetically packaged GaAs power FETs with approximately 0.5 W output power. The study includes device physical, electrical cw and pulsed, and environmental characterization, electrical cw and pulsed and environmental stress tests, and failure analysis. The device physical characterization has been completed and the data are presented. The cw electrical characterization is almost complete, and detailed data are shown for a typical device. No device had significant changes in electrical parameters following operation for 1000 hours at room temperature. The environmental characterization has just begun, and no results are available yet. The results from the cw electrical stress tests, which have been completed, are presented. There are some correlations between the various device structures and the results from different manufactures devices. The environmental stress tests have begun, and preliminary results are presented. Most of the effort for the remainder of the program will be spent on completing these tests. The pulse characterization and stress tests have not yet begun. The failure analyses are described along with the test causing the failure. Author