Process using poly-buffered STI
AssigneeInternational Business Machines Corporation
InventorChung Hon Lam
Life of this patent
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Abstract
A method of providing a substantially planar trench isolation region having substantially rounded corners, said method comprising the steps of: (a) forming a film stack on a surface of a substrate, said film stack comprising an oxide layer, a polysilicon layer and a nitride layer; (b) patterning said film stack to form at least one trench within said substrate, wherein said patterning exposes sidewalls of said oxide layer, polysilicon layer and nitride layer; (c) oxidizing the at least one trench and said exposed sidewalls of said oxide layer and said polysilicon layer so as to thermally grow a conformal oxide layer in said trench and on said exposed sidewalls of said oxide layer and said polysilicon layer; (d) filling said trench with a trench dielectric material; and (e) planarizing to said surface of said substrate.
Claims7
A semiconductor device comprising at least one substantially planarized trench isolation region formed within a substrate electrically isolating adjacent active device regions from each other, said at least one planarized trench isolation region containing a conformal oxide liner confined within and along sidewalls of said at least one planarized trench isolation region, wherein said conformal oxide liner has rounded corners extending beyond a top surface of said substrate and a trench dielectric filling said at least one substantially planarized trench isolation region.
A semiconductor device comprising at least one substantially planarized trench isolation region formed within a substrate electrically isolating adjacent active device regions from each other, said at least one planarized trench isolation region containing a dielectric fill and a conformal thermal oxide liner confined within and along sidewalls of said at least one planarized trench isolation region, wherein said conformal oxide liner has edges having rounded portions extending from a conformal oxide liner/substrate interface and a conformal oxide liner/dielectric fill interface, wherein said rounded portions extend beyond top surface is said substrate.
Dependencies are inferred from the claim text.