Methods for forming shallow trench isolation structures in semiconductor devices

摘要

Methods for forming STI structures in semiconductor devices are disclosed. A disclosed method comprises: forming a buffer oxide layer on a silicon substrate; implanting ions into the entire surface of the resulting structure and removing the buffer oxide layer; depositing a gate oxide layer, a polysilicon layer and a nitride layer, forming a photoresist pattern; forming the trench of the STI structure by perform an etching process using the photoresist pattern as an etching mask; forming a thin oxide layer inside the trench and on the nitride layer on the entire surface of the resulting structure; filling the trench with an insulating layer; planarizing the insulating layer by performing a CMP process using the nitride layer as an etching stop layer; performing a recessing process to etch the planarized insulating layer and the thin oxide layer on the trench to a predetermined depth; forming a photoresist pattern on the nitride layer; and forming the gate electrodes by performing an etching process using the photoresist pattern as a mask pattern.