Patent ID: 6180493
Filing Date: 2001-01-30
Classification: H01L

Abstract:
A method for forming shallow trench isolation region, comprising the steps of:providing a substrate;forming a pad oxide layer over the substrate;forming a mask layer over the pad oxide layer;patterning the mask layer and the pad oxide layer to form an opening;forming a trench in the substrate using the mask layer as a hard mask;oxidizing the exposed substrate surface of the trench to form a first liner layer;forming a second liner layer conformal to the surface profile of the substrate;forming a buffer layer conformal to the surface profile of the substrate;forming a first insulation layer within the trench and the opening such that the upper surface of the first insulation layer is at a level between the upper surface and the lower surface of the mask layer;removing a portion of the buffer layer that covers the second liner layer so that the upper ends of the buffer layer is at a level between the upper surface and the lower surface of the mask layer;forming a second insulation layer that fills the opening over the first insulation layer;removing a portion of the second liner layer above the mask layer;removing the mask layer; andremoving the pad oxide layer.