FORMING METHOD OF TRENCH OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a trench of a semiconductor device is to prevent from oxidizing of an active region of a silicon substrate when an oxidation layer is deposited to form an oxidation layer spacer. CONSTITUTION: A trench forming method comprises the steps of: forming a pad oxidation layer(2) and a pad nitrification layer(3) serially on a silicon substrate(1), applying a photoresist(5) to the pad nitrification layer, and patterning the photoresist; etching the nitrification layer using the patterned photoresist as a mask to expose the pad oxidation layer, and removing the photoresist; depositing a nitrification layer(6) on the former layer, and etching the nitrification layer to form a nitrification layer spacer(7) such that a portion of the silicon substrate between the nitrification layer spacers is secured as an active region on which a trench(9) is formed; depositing an oxidation layer(4) on the former layer, and etching the oxidation layer and the exposed pad oxidation layer to form an oxidation layer spacer(8) and to expose the silicon substrate on which a trench is formed; etching the exposed silicon substrate to form the trench; and removing the oxidation layer spacer and pad oxidation layer under the same.