Patent ID: 8129235
Filing Date: 2012-03-06
Classification: H01L

Abstract:
1. A method of fabricating a two-step self-aligned contact, comprising: providing a substrate having a contact region thereon; forming a first dielectric layer on the substrate, wherein the first dielectric layer comprises an etch stop layer, an endpoint detection layer, and a stress layer, which are stacked from bottom to top, and cover from the contact region of the substrate to other region of the substrate; forming a lower hole corresponding to the contact region in the first dielectric layer to expose the endpoint detection layer at a bottom of the lower hole; after forming the lower hole, forming a second dielectric layer to directly contact the stress layer, wherein the lower hole is filled with the second dielectric layer to directly contact endpoint detection layer or the stress layer at the bottom of the lower hole; forming an upper hole self-aligned to and communicated with the lower hole in the second dielectric layer and removing the etch stop layer and the endpoint detection layer at the bottom of the lower hole to expose the contact region, wherein the upper hole and the lower hole constitute a self-aligned contact hole; and filling the self-aligned contact hole with a conductive layer.