Conformal oxide dry etch
AssigneeApplied Materials, Inc.
InventorsAnchuan Wang, Jingchun Zhang, Nitin K. Ingle, Young S. Lee
Life of this patent
Estimating the term…
Abstract
A method of etching silicon oxide from a trench is described which allows more homogeneous etch rates up and down the sides of the trench. One disclosed method includes a sequential introduction of (1) a hydrogen-containing precursor and then (2) a fluorine-containing precursor into a substrate processing region. The temperature of the substrate is low during each of the two steps in order to allow the reaction to proceed and form solid residue by-product. A second disclosed method reverses the order of steps (1) and (2) but still forms solid residue by-product. The solid residue by-product is removed by raising the temperature in a subsequent sublimation step regardless of the order of the two steps.
Claims18
A method of etching silicon oxide from the walls of a trench on a surface of a patterned substrate in a substrate processing region of a substrate processing chamber, the method comprising
- at least four sequential steps comprising:
- (i) exposing the patterned substrate to hydrogen by flowing a hydrogen-containing precursor into the substrate processing region,
- (ii) removing process effluents including unadsorbed hydrogen-containing precursor from the substrate processing region,
- (iii) exposing the patterned substrate to fluorine by flowing a fluorine-containing precursor into the substrate processing region to form solid by-products on the patterned substrate, and
- (iv) removing process effluents including unreacted fluorine-containing precursor from the substrate processing region;
- and
- further comprising a sublimation operation of raising a temperature of the substrate above a sublimation temperature to remove the solid by-products, wherein the sublimation operation occurs after the step of exposing the patterned substrate to fluorine, and wherein the at least four sequential steps in combination with the sublimation operation are referred to collectively as an etch cycle.
A method of etching silicon oxide from the walls of a trench on a surface of a patterned substrate in a substrate processing region of a substrate processing chamber, the method comprising
- at least four sequential steps comprising:
- (i) exposing the patterned substrate to fluorine by flowing a fluorine-containing precursor into the substrate processing region,
- (ii) removing process effluents including unadsorbed fluorine-containing precursor from the substrate processing region,
- (iii) exposing the patterned substrate to hydrogen by flowing a hydrogen-containing precursor into the substrate processing region to form solid by-products on the patterned substrate, and
- (iv) removing process effluents including unreacted hydrogen-containing precursor from the substrate processing region;
- and
- further comprising a sublimation operation of raising a temperature of the substrate above a sublimation temperature to remove the solid by-products, wherein the sublimation operation occurs after the step of exposing the patterned substrate to hydrogen, and wherein the at least four sequential steps in combination with the sublimation operation are referred to collectively as an etch cycle.
Dependencies are inferred from the claim text.