Patent ID: 6482716
Filing Date: 2002-11-19
Classification: H01L

Abstract:
A method for forming uniform-depth recesses across areas of different trench density comprising the steps of:providing a substrate having trenches formed therein, the substrate including at least two regions, each of the at least two regions having a different trench density, blanketing a first filler material layer over the substrate to a depth effective in filling the trenches in the at least two regions with first filler material, the first filler material layer having a depth above the substrate that is a function of the different trench densities; etching the first filler material layer to substantially remove the first filler material from a surface of the substrate while leaving the trenches substantially filled with the first filler material while forming recesses in trenches in a region having a highest density of trenches; forming a second filler material over the substrate, and refilling the trenches in the at least two regions, the second filler material having a depth above the substrate that is substantially uniform across the different trench densities of the at least two regions; and etching the first and second filler materials to form recesses in the trenches, the recesses having a substantially same depth across the different trench densities of the at least two regions.