Reliability of a high performance monolithic IC fabricated using a production GaAs/AlGaAs HBT process

We report the world's first lifetest results of a monolithic integrated circuit fabricated using GaAs/AlGaAs Heterojunction Bipolar Transistor (HBT) technology. The Successive Detection Logarithmic Amplifier (SDLA) was used as the standard evaluation circuit (SEC) to evaluate the HBT process. Results of a three temperature constant stress lifetest projects a median-time-to-failure (MTF) of >10/sup 7/ hours at 125/spl deg/C junction temperature with an activation energy (Ea) of 1.4 eV and log-sigma (/spl sigma/) of 0.7. Failure criteria were based on RF and DC characteristics of the SDLA. Failure mode is also discussed. This study establishes GaAs/AlGaAs HBT technology as a mature and reliable process technology.