摘要:
A method and apparatus for depositing self-aligned base contacts where over-etching the emitter sidewall to undercut the emitter contact is not needed. A semiconductor structure has a T-shaped emitter contact that comprises a T-top and T-foot. The T-top acts as a mask for depositing the base contacts. In forming the T-top, its dimensions may be varied, thereby allowing the spacing between the base contacts and emitter to be adjusted.
摘要:
A method is provided for improving edge terminations in a semiconductor device while maintaining breakdown voltage of said semiconductor device at or near its theoretical limit. The method comprises: employing ion-implantation to create a compensated region around the semiconductor device, followed by wet chemical etching to form a mesa on the order of 0.2 to 0.3 &mgr;m. The method provides a simple but novel approach to fabricate edge terminations in semiconductor devices in general and in devices employing p-n junctions such as in a GaAs heterojunction bipolar transistor (HBT) to achieve near-ideal electrical characteristics at the device edge. Instead of traditional edge beveling techniques such as those involving grinding, sandblasting, or mesa-etching using masks, the technique disclosed herein utilizes ion-implantation to create a compensated region around the device and wet chemical etching to make a shallow mesa.