SYNCHRONIZED RADIO FREQUENCY PULSING FOR PLASMA ETCHING
First Claim
1. A method of etching a dielectric layer on a substrate, comprising:
- generating a plasma by pulsing a first RF source signal having a first duty cycle;
applying a second RF bias signal having a second duty cycle to the plasma;
applying a third RF bias signal having a third duty cycle to the plasma, wherein the first, second, and third signals are synchronized;
adjusting a phase variance between the first RF source signal and at least one of the second or third RF bias signals to control at least one of plasma ion density non-uniformity in the plasma or charge build-up on the dielectric layer; and
etching the dielectric layer with the plasma.
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Accused Products
Abstract
Methods for processing a substrate are provided herein. In some embodiments, a method of etching a dielectric layer includes generating a plasma by pulsing a first RF source signal having a first duty cycle; applying a second RF bias signal having a second duty cycle to the plasma; applying a third RF bias signal having a third duty cycle to the plasma, wherein the first, second, and third signals are synchronized; adjusting a phase variance between the first RF source signal and at least one of the second or third RF bias signals to control at least one of plasma ion density non-uniformity in the plasma or charge build-up on the dielectric layer; and etching the dielectric layer with the plasma.
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Citations
20 Claims
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1. A method of etching a dielectric layer on a substrate, comprising:
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generating a plasma by pulsing a first RF source signal having a first duty cycle; applying a second RF bias signal having a second duty cycle to the plasma; applying a third RF bias signal having a third duty cycle to the plasma, wherein the first, second, and third signals are synchronized; adjusting a phase variance between the first RF source signal and at least one of the second or third RF bias signals to control at least one of plasma ion density non-uniformity in the plasma or charge build-up on the dielectric layer; and etching the dielectric layer with the plasma. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20)
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18. A method of etching a dielectric layer on a substrate disposed on a substrate support of a capacitively coupled plasma etching reactor having an upper electrode disposed above the substrate and a lower electrode disposed in the substrate support, comprising:
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generating a plasma to etch the dielectric layer by pulsing a first RF source signal coupled to the upper electrode, the first RF source signal having a first duty cycle; applying a second RF bias signal having a second duty cycle to the lower electrode; applying a third RF bias signal having a third duty cycle to the lower electrode, wherein the first, second, and third signals have a common pulse frequency; and adjusting at least one of a phase variance or a duty cycle of the first RF source signal with respect to at least one of the second or third RF bias signals to control at least one of plasma ion density non-uniformity, charge build-up on the dielectric layer, or etch rate of the dielectric layer.
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Specification