Atomic layer etching of tungsten and other metals
First Claim
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1. A method comprising:
- (a) exposing a surface of a metal on a substrate to a halide chemistry to form a modified halide-containing surface layer, the metal being selected from the group consisting of tungsten (W) and cobalt (Co); and
(b) applying a bias voltage to the substrate while exposing the modified halide-containing surface layer to a plasma to thereby remove the modified halide-containing surface layer.
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Abstract
Provided herein are methods of atomic layer etching (ALE) of metals including tungsten (W) and cobalt (Co). The methods disclosed herein provide precise etch control down to the atomic level, with etching a low as 1 Å to 10 Å per cycle in some embodiments. In some embodiments, directional control is provided without damage to the surface of interest. The methods may include cycles of a modification operation to form a reactive layer, followed by a removal operation to etch only this modified layer. The modification is performed without spontaneously etching the surface of the metal.
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16 Claims
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1. A method comprising:
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(a) exposing a surface of a metal on a substrate to a halide chemistry to form a modified halide-containing surface layer, the metal being selected from the group consisting of tungsten (W) and cobalt (Co); and (b) applying a bias voltage to the substrate while exposing the modified halide-containing surface layer to a plasma to thereby remove the modified halide-containing surface layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method
(a) exposing a tungsten surface on a substrate to a chlorine-containing plasma to form a tungsten-containing and chlorine-containing surface layer at substrate temperature less than 150° - C.; and
(b) applying a bias voltage to the substrate while exposing the tungsten-containing and chlorine-containing surface layer to ions generated from an inert gas plasma to thereby remove tungsten-containing and chlorine-containing surface layer. - View Dependent Claims (15, 16)
- C.; and
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