Method of reducing the roughness of a gate insulator layer after exposure of the gate insulator layer to a threshold voltage implantation procedure
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChie-Chi Chen, Sheng-Liang Pan
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Abstract
A process for reducing the surface roughness of a silicon dioxide gate insulator layer, that has been subjected to a boron ion implantation procedure, has been developed. The process features the use of an ammonium hydroxide-hydrogen peroxide solution, applied to the gate insulator layer, to reduce the surface roughness of the gate insulator layer, created by the boron ion implantation procedure. The treatment of the gate insulator layer, in the ammonium hydroxide-hydrogen peroxide solution, results in a surface roughness equivalent to the surface roughness of the gate insulator layer, prior to the boron ion implantation procedure.
Claims15
A method of reducing the surface roughness of a gate insulator layer, on a semiconductor substrate, comprising the steps of:
- growing a first gate insulator layer, comprised with a first surface roughness, on said semiconductor substrate;
- performing an ion implantation procedure, thorough said first gate insulator layer, forming a threshold adjust region in said semiconductor substrate, and converting said first gate insulator layer to a second gate insulator layer, with said second gate insulator layer comprised with a second surface roughness;
- and
- performing a treatment in a solution comprised with an ammonium peroxide mixture, to convert said second gate insulator layer to a third gate insulator layer, with said third gate insulator layer comprised with a third surface roughness.
A method of reducing the surface roughness of a silicon dioxide gate insulator layer, on a semiconductor substrate, via treatment in a solution containing an ammonium peroxide mixture, comprising the steps of:
- growing a first silicon dioxide gate insulator layer, comprised with a first surface roughness, on said semiconductor substrate;
- performing a boron ion implantation procedure through said first silicon dioxide gate insulator layer, to form a threshold adjust region in said semiconductor substrate, and converting said first silicon dioxide gate insulator layer to a second silicon dioxide gate insulator layer, with said second silicon dioxide gate insulator layer comprised with a second surface roughness;
- performing said treatment, in said ammonium peroxide mixture, comprised of ammonium hydroxide and hydrogen peroxide, to convert said second silicon dioxide gate insulator layer to a third silicon dioxide gate insulator layer, with said third silicon dioxide gate insulator layer comprised with a third surface roughness.
Dependencies are inferred from the claim text.