Method for fabricating VLSI devices having trench isolation regions
AssigneeMosel Vitelic, Inc.
InventorJacson Liu
Life of this patent
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Abstract
A process for fabricating a VLSI device comprising trench isolation regions. The trench isolation regions of a VLSI device is fabricated by a process comprising the following steps: Depositing and patterning pad layers on a substrate to form active regions separated from pad-layer-covered regions; forming side walls at each active region to cover portions of the active region other than its central portion; depositing a first oxide at the space surrounded by the side walls and the central portion of the active region; removing the side walls to form trenches at the active region; and depositing a second oxide on the substrate to fill the trenches and cover the first oxide, the second oxide and the first oxide together forming an oxide trench isolation region.
Claims19
A process of fabricating a plurality of oxide trench isolation regions on a substrate, comprising the steps of:
- depositing one or more pad layers on said substrate;
- removing portions of said pad layers and the surface regions of said substrate underneath said removed portions of said pad layers to pattern said pad layers and to form a plurality of active regions separated from a plurality of regions covered by said patterned pad layers;
- forming one or more side walls at each said active region to cover portions of said active region other than the central portion of said active region;
- depositing a first oxide at the space surrounded by said side walls and said central portion of said active region;
- removing said side walls and forming one or more trenches at said active region;
- and
- forming a second oxide to fill said trenches and cover said first oxide, said second oxide and said first oxide together forming one of said oxide trench isolation regions.
A process of fabricating a plurality of trench isolation regions on a substrate of a VLSI device, comprising the steps of:
- depositing one or more pad layers on said substrate;
- r emoving portions of said pad layers and the surface regions of said substrate underneath said removed portions of said pad layers to pattern said pad layers and to form a plurality of active regions separated from a plurality of regions covered by said patterned pad layers;
- forming one or more side walls at each said active region to cover portions of said active region other than the central portion of said active region;
- depositing a first oxide at the space surrounded by said side walls and said central portion of said active region;
- removing said side walls and forming one or more trenches at said active region;
- depositing a polysilicon to fill said trenches and cover said first oxide, said polysilicon comprising integrally a top portion and a bottom portion;
- and
- oxidizing said top portion of said polysilicon to form a second oxide, said second oxide and said first oxide together forming an oxide mass, said oxide mass and said bottom portions of said polysilicon together forming one of said trench isolation regions.
Dependencies are inferred from the claim text.