FABRICATION OF VERTICAL-CAVITY FRONT-SURFACE-EMITTING LASER DIODE (FSELD) USING A HETEROJUNCTION BIPOLAR-TRANSISTOR PROCESS

Abstract

We have investigated a front-surface-emitting laser diode (FSELD) which has both the n and p electrodes on the top surface and emits laser light from the front surface of the wafer. Since its structure is similar to that of HBT, it was fabricated using the conventional HBT process and mask sets. The current flows bypassing the high-series-resistance DBR stacks, and the active layer is surrounded by an oxygen-implanted semi-insulating layer. It showed a low series resistance and low threshold current of 6 mA, for a 25-mu-m-diameter laser.