Method for manufacturing a semiconductor integrated circuit.

摘要

A method for manufacturing a semiconductor integrated circuit includes diffusing an impurity of a second conductivity type into polycrystalline silicon layers (10) formed on a first conductivity region (5) in a substrate (1) to form second conductivity regions (13), the polycrystalline silicon layers (10) constituting first electrode wirings to the second conductivity regions (13); forming a thick oxidation film (11) on the polycrystalline silicon layers (10) and a thin oxidation film (12) on the exposed surface of the substrate by a heat oxidation treatment; and removing the thin oxidation film (12) to form a second electrode wiring to the first conductivity region (5), said second electrode wiring being insulated from the polycrystalline silicon layers (10) by the thick oxidation film (11). The method provides integrated circuits such as 12L circuits which are capable of high speed operation and a high packaging density.