Self-aligned wet etching process

Abstract

A self-aligned wet etching process comprises the steps of: etching a substrate having an etch protection layer on a surface thereof to form a plurality of trenches spaced from each other; and sequentially forming an insulating layer, an etch stop layer and a primary insulator in each trench, wherein the primary insulator is filled inside an accommodation space surrounded by the etch stop layer. During the wet etching process, the etch stop layer protects the primary insulator from being etched, whereby is achieved anisotropic wet etching. Further, the present invention expands the contact areas for electrically connecting with external circuits and exempts the electric contactors formed on the contact areas from short circuit caused by excessively etching the primary insulators.