Method of making through wafer vias
AssigneeInternational Business Machines Corporation
InventorsPaul Stephen Andry, Edmund Juris Sprogis, Cornelia Kang-I Tsang
Life of this patent
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Abstract
A method of making a through wafer via. The method includes: forming a trench in a semiconductor substrate, the trench open to a top surface of the substrate; forming a polysilicon layer on sidewalls and a bottom of the trench; oxidizing the polysilicon layer to convert the polysilicon layer to a silicon oxide layer on the sidewalls and bottom of the trench, the silicon oxide layer not filling the trench; filling remaining space in the trench with an electrical conductor; and thinning the substrate from a bottom surface of the substrate and removing the silicon oxide layer from the bottom of the trench. The method may further include forming a metal layer on the silicon oxide layer before filling the trench.
Claims20
A method, comprising:
- forming a trench in a semiconductor substrate, said trench open to a top surface of said substrate;
- forming a polysilicon layer on sidewalls and a bottom of said trench;
- oxidizing said polysilicon layer to convert said polysilicon layer to a silicon oxide layer on said sidewalls and bottom of said trench, said silicon oxide layer not filling said trench;
- filling remaining space in said trench with an electrical conductor;
- and
- thinning said substrate from a bottom surface of said substrate and removing said silicon oxide layer from said bottom of said trench.
The method of 1, wherein said oxidizing said polysilicon layer is performed using a high pressure oxidation (HIPOX) process.
A method, comprising:
- forming a trench in a semiconductor substrate, said trench open to a top surface of said substrate;
- forming a polysilicon layer on sidewalls and a bottom of said trench;
- oxidizing said polysilicon layer to convert said polysilicon layer to a silicon oxide layer on said sidewalls and bottom of said trench, said silicon oxide layer not filling said trench;
- forming a metal layer on said silicon oxide layer, said metal layer not filling said trench;
- filling remaining space in said trench with a polysilicon fill;
- and
- thinning said substrate from a bottom surface of said substrate and removing said silicon oxide layer from said bottom of said trench.
The method of 12, wherein said oxidizing said polysilicon layer is performed using a high pressure oxidation (HIPOX) process.
Dependencies are inferred from the claim text.