Device and methods for forming partially self-aligned trenches

摘要

A semiconductor device and methods for small trench patterning are disclosed. The device includes a plurality of gate structures and sidewall spacers, an etch stop layer disposed over the sidewall spacers, an interlayer dielectric (ILD) layer disposed on a bottom portion of the etch stop layer, an etch buffer layer disposed on an upper portion of the etch stop layer, and a plurality of metal plugs between the gate structures. An upper portion of the metal plugs is adjacent to the etch buffer layer and a lower portion of the metal plugs is adjacent to the ILD layer.

主权项

1. A method of making a semiconductor device, the method comprising:
forming a gate structure over a semiconductor substrate; forming a sidewall spacer adjoining a sidewall of the gate structure; forming an etch stop layer over the sidewall spacer; forming a first interlayer dielectric (ILD) layer over the etch stop layer; planarizing the first ILD layer; forming an etch buffer layer over the planarized first ILD layer; forming a second ILD layer over the etch buffer layer; forming trenches in the second ILD layer and the etch buffer layer; filling the trenches with a conductive material; and planarizing the conductive material.