Directional SiO2 etch using plasma pre-treatment and high-temperature etchant deposition
AssigneeApplied Materials, Inc.
InventorsDavid T. Or, Joshua Collins, Mei Chang
Life of this patent
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Abstract
Methods for processing a substrate are described herein. Methods can include positioning a substrate with an exposed surface comprising a silicon oxide layer in a processing chamber, biasing the substrate, treating the substrate to roughen a portion of the silicon oxide layer, heating the substrate to a first temperature, exposing the exposed surface of the substrate to a plasma comprising ammonium fluoride to form one or more volatile products while maintaining the first temperature, and heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.
Claims20
A method, comprising:
- positioning a substrate in a processing chamber, the substrate comprising:
- a patterned layer having an upper surface and one or more features formed in the patterned layer, the one or more features having a bottom surface and a side surface;
- and
- an oxide layer formed on the upper surface, the bottom surface, the side surface, or combinations thereof;
- while biasing the substrate, exposing the substrate to an inert plasma to selectively form a pretreated surface on the oxide layer formed over the upper surface and the bottom surface, wherein the oxide layer formed over the upper surface and the bottom surface is selectively roughened;
- after exposing the substrate to the inert plasma, heating the substrate to a first temperature;
- exposing the substrate to a processing gas comprising ammonium fluoride (NH4F) or NH4F(HF), wherein the processing gas reacts with the oxide layer to form one or more volatile products on the upper surface and the bottom surface, and wherein the processing gas reacts preferentially with the oxide layer on the upper surface and the bottom surface, the substrate being maintained at the first temperature;
- and
- heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the one or more volatile products.
A method, comprising:
- positioning a silicon-containing substrate in a processing chamber, the silicon-containing substrate comprising:
- a first surface;
- one or more features formed in the first surface, the features having a bottom surface and a side surface;
- and
- an oxide layer formed on the first surface, the bottom surface, the side surface or combinations thereof;
- biasing the substrate;
- exposing the substrate to an inert plasma to selectively form a roughened surface from the portions of the oxide layer of the first surface perpendicular to the flow of the inert plasma;
- heating the substrate to a first temperature;
- exposing the surface of the substrate to a plasma comprising ammonium fluoride (NH4F), wherein the NH4F reacts with the oxide layer to form one or more volatile products, and wherein the NH4F reacts preferentially with the oxide layer on the roughened surface of the first surface;
- and
- heating the substrate to a second temperature, which is higher than the first temperature, to sublimate the volatile products.
Dependencies are inferred from the claim text.