Method of forming trenches

摘要

The present invention provides a method for forming trenches. First, a mandrel layer is formed on a substrate, wherein the mandrel layer comprises a stop layer and a sacrificial layer. A spacer is formed on at least a sidewall of the mandrel layer, following by forming a material layer on the substrate for covering the spacer and the mandrel layer. After performing a removing process to remove apart of the material layer, apart of the spacer and the sacrificial layer; the spacer is removed to form at least one first trench in the remaining material layer and the mandrel.

主权项

1. A method of forming trenches, comprising:
forming a mandrel layer on a substrate, wherein the mandrel layer comprises a stop layer and a sacrificial layer; forming a spacer on at least a sidewall of the mandrel layer; forming a material layer on the spacer and the mandrel layer; performing a removing process to remove a part of the material layer, a part of the spacer and the sacrificial layer, wherein after the removing process, a top surface of the stop layer is leveled with a top surface of the spacer and a top surface of the material layer; and removing the spacer to form at least one first trench in the remaining material layer and the mandrel layer.