METHOD FOR PREVENTING OVER ETCH OF BASE IN FABRICATION PROCESS OF TRANSFERRED-SUBSTRATE HETEROJUNCTION BIPOLAR TRANSISTOR

摘要

Purpose: a kind of method, for one transfer substrate heterojunction bipolar transistor a manufacturing process in a base corrosive agent on prevent be the etching process on the corrosive agent of bottom in collector layer during prevent. Construction: a Prevention method of a bottom includes the following steps:: forming a bar ditch in a selected region of a base object layer (20), is used to form the base region before forming a collector region; A photoresist mode is formed on base object layer around ditch; The metal layer being deposited in photoresist mode includes ditch; Take off photoresist jargon and covering metal layer, forms the index that can be felt in the depth by the etching in ditch exposure and the collector object layer (30) for being used to form collector region; Collector object layer is etched to form collector region, such base object layer is all without excessive erosion when feeling index.