TW357539B - Method for forming built-in layers in semiconductor substrates - Google Patents

Abstract

A method for forming built-in layers in semiconductor substrates by forming built-in polarities in a semiconductor substrate before making the base and emission polarity of the transistor in the semiconductor substrate on top of the integration polarity, including the method the following steps: (a) deposition padded oxide layer and silicon nitride layer on the surface of the semiconductor substrate; (b) etching the padded oxide layer and silicon nitride layer, for exposing part of the surface of the semiconductor substrate; (c) ion planting with dopant in said semiconductor substrate, with forming of built-in layer, for built-in integration of the transistor; (d) thermal oxidization for forming oxide layer on the surface of the semiconductor substrate; (e) removal of part of the silicon nitride layer, leaving the silicon nitride layer between the oxide layers, coating the surface of the semiconductor substrate, for defining the active region of the transistor; (f) heating with forming of field oxide layer in the area not coated by the silicon nitride layer and making the built-in layer area expand, for the bilt-in layer and the field oxide layer cover a part of the semiconductor substrate, as active region of the transistor; (g) continous transistor processing in the active region of the transistor.