Patent ID: 6268264
Filing Date: 2001-07-31
Classification: H01L

Abstract:
A method of forming a shallow trench isolation, comprising:providing a substrate;forming a pad oxide layer on the substrate;forming a hard mask layer on the pad oxide layer;removing a part of the hard mask layer, the pad oxide layer, and the substrate to form a trench in the substrate;forming a liner oxide along the trench surface;forming an insulation layer on the hard mask layer to fill the trench;etching back the insulation layer with the hard mask layer as an etching stop;removing the hard mask layer without removing the pad oxide layer to form an insulation plug with an upper portion outstanding the substrate that is covered by the pad oxide layer;forming a silicon layer on the substrate, which is covered by the pad oxide layer, and the insulation plug;etching back the silicon layer to form a silicon spacer on a side wall of the outstanding upper portion of the insulation plug; andusing thermal oxidation to transform the silicon spacer into a silicon oxide spacer;after the silicon oxide spacer is formed, removing the pad oxide layer; andafter the pad oxide layer is removed, forming a gate oxide layer on the substrate.