BIAS-TEMPERATURE LIFE TESTS FOR PLANAR-TYPE VPE-GROWN INGAAS/INP HETEROSTRUCTURE APD'S.

Following a discussion of device fabrication, bias-temperature life tests carried out at three temperature levels (80, 120, and 180 degree C) are described. Low-bias life tests (V//R equals 10 V) were tried at first for the diodes without a guard-ring structure for times exceeding 10,000 h. The heterostructure avalanche photodiodes (HAPDs) with the guard-ring have been tested under the condition of high electric field ( greater than 4 multiplied by 10**5 V/cm). The stable devices have been operating up to 6000 h under the high field condition even at 180 degree C. The HAPDs are still prototypes. Thus, the test results are considered to be encouraging as to achieving highly reliable photodiodes.