METHOD OF ETCHING SHAPED FEATURES ON A SUBSTRATE
First Claim
1. A substrate etching method comprising:
- (a) providing a substrate in a process zone, the substrate having a pattern of features comprising dielectric covering semiconductor;
(b) in a first stage, providing in the process zone, an energized first etching gas having a first selectivity of etching dielectric to semiconductor of at least about 1.8;
1, wherein the dielectric is etched preferentially to the semiconductor to etch through the dielectric to at least partially expose the semiconductor; and
(c) in a second stage, providing in the process zone, an energized second etching gas having a second selectivity of etching dielectric to semiconductor of less than about 1;
1.8, wherein the semiconductor is etched preferentially to the dielectric.
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Abstract
In a method of etching a substrate, a substrate is provided in a process zone, the substrate having a pattern of features comprising dielectric covering semiconductor. In a first stage, an energized first etching gas is provided in the process zone, the energized first etching gas having a first selectivity of etching dielectric to semiconductor of at least about 1.8:1, wherein the dielectric is etched preferentially to the semiconductor to etch through the dielectric to at least partially expose the semiconductor. In a second stage, an energized second etching gas is provided in the process zone, the energized second etching gas having a second selectivity of etching dielectric to semiconductor of less than about 1:1.8, wherein the semiconductor is etched preferentially to the dielectric.
15 Citations
29 Claims
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1. A substrate etching method comprising:
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(a) providing a substrate in a process zone, the substrate having a pattern of features comprising dielectric covering semiconductor;
(b) in a first stage, providing in the process zone, an energized first etching gas having a first selectivity of etching dielectric to semiconductor of at least about 1.8;
1, wherein the dielectric is etched preferentially to the semiconductor to etch through the dielectric to at least partially expose the semiconductor; and
(c) in a second stage, providing in the process zone, an energized second etching gas having a second selectivity of etching dielectric to semiconductor of less than about 1;
1.8, wherein the semiconductor is etched preferentially to the dielectric. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of etching a substrate in a substrate processing chamber comprising an antenna and process electrodes, the method comprising:
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(a) providing a substrate in the chamber, the substrate having a pattern of features, the features comprising a semiconductor mesa with a dielectric sidewall;
(b) in a first plasma stage, providing a first etching gas in the chamber and applying a first bias RF power level to the process electrodes and a first source RF power level to the antenna, thereby energizing the first etching gas to etch the semiconductor mesa and the dielectric sidewall; and
(c) in a second plasma stage, providing an energized second etching gas in the chamber and applying a second bias RF power level to the process electrodes and a second source RF power level to the antenna, thereby energizing the second etching gas to etch the semiconductor mesa and a remaining portion of the dielectric sidewall. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A method of etching a substrate in a substrate processing chamber comprising an antenna and process electrodes:
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(a) providing a substrate in the chamber, the substrate having a pattern of features, the features comprising a semiconductor mesa covered by a dielectric top wall and dielectric sidewalls, (b) in a first etching stage, providing in the chamber, an energized first etching gas comprising a halogenated non-hydrogen-containing gas and a halogenated hydrogen-containing gas in a volumetric ratio selected to etch the dielectric top wall to expose the semiconductor mesa; and
(c) in a second etching stage, providing in the chamber, an energized second etching gas comprising the halogenated non-hydrogen-containing gas and a chlorine-containing gas in a volumetric ratio selected to etch the semiconductor mesa and the dielectric sidewalls;
(d) in a third etching stage, providing a third etching gas in the chamber and applying a first bias RF power level to the process electrodes and a first source RF power level to the antenna, thereby energizing the third etching gas to further etch the semiconductor mesa and the dielectric sidewalls; and
(e) in a fourth etching stage, providing an energized fourth etching gas in the chamber and applying a second bias RF power level to the process electrodes and a second source RF power level to the antenna, thereby energizing the second etching gas to etch the semiconductor mesa and a remaining portion of the dielectric sidewalls. - View Dependent Claims (17, 18, 19, 20, 21)
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22. A method of etching a substrate in a chamber comprising an antenna and process electrodes, the method comprising:
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(a) providing the substrate in the chamber;
(b) in a first stage, providing in the chamber, an energized first etching gas comprising CF4 and CHF3;
(c) in a second stage, providing in the chamber, an energized second etching gas comprising CF4 and C!2;
(d) in a third stage, providing in the chamber, a third etching gas comprising Ar, CF4 and O2, and applying a first bias RF power level to the process electrodes and a first source RF power level to the antenna;
(e) in a fourth stage, providing in the chamber, an energized fourth etching gas comprising Ar and CF4, and applying a second bias RF power level to the process electrodes and a second source RF power level to the antenna; and
(f) in a fifth stage, providing in the chamber, an energized fifth etching gas comprising HBr, Cl2 and HeO2. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A method of etching a pattern of features on a substrate in a chamber comprising an antenna and process electrodes, the method comprising:
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(a) providing a substrate in the chamber;
(b) in a first stage, providing in the chamber, an energized first etching gas comprising CF4 and CHF3 in a volumetric flow ratio of from about 4;
1 to about 1;
4;
(c) in a second stage, providing in the chamber, an energized second etching gas comprising CF4 and Cl2 in a volumetric flow ratio of from about 5;
1 to about 2;
1;
(d) in a third stage, providing in the chamber, a third etching gas comprising Ar, CF4 and O2, in a volumetric flow ratio of Ar to (CF4 and O2) of from about 1;
1 to about 2;
1, applying a first bias RF power level of from about 0 Watts to about 50 Watts to the process electrodes, and applying a first source RF power level of from about 800 to about 1500 Watts to the antenna to energize the third etching gas;
(e) in a fourth stage, providing in the chamber, an energized fourth etching gas comprising Ar and CF4 in a volumetric flow ratio of from about 8;
1 to about 20;
1, applying a second bias RF power level to the process electrodes of from about 150 Watts to about 300 Watts, and applying a second source RF power level to the antenna of from about 200 Watts to about 400 Watts to energize the second etching gas; and
(f) in a fifth stage, providing in the chamber, an energized fifth etching gas comprising HBr, Cl2 and HeO2.
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Specification