Dry etching method
First Claim
1. A dry etching method for etching silicon material layers by using plasma of a gas mixture including oxygen and at least one halogen/halide, the method including the steps of:
- measuring intensities of a first emission from the plasma at a first wavelength and a second emission from the plasma at a second wavelength;
obtaining a ratio of the intensity of the first emission to that of the second emission;
measuring selectivity of silicon material layers to an oxide layer formed over a substrate for a condition of the plasma for which the emission intensity ratio is obtained;
obtaining a correlation between the emission intensity ratio and the selectivity; and
setting a plasma condition for a desired selectivity based on a measured emission intensity ratio by using the correlation.
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Accused Products
Abstract
Silicon material layers formed on an oxide underlayer are attached using a plasma including a gas mixture of a halogen and oxygen. Intensities of first emissions from the plasma at a first wavelength and second emissions from the plasma at a second wavelength are measured. A ratio of the first emissions intensity to the second emissions intensity is determined. The selectivity of silicon layers to oxide underlayers is measured for various conditions of the plasma under which the emissions intensity ratio is obtained. A correlation between the emissions intensity ratio and the selectivity is then established for various etching parameters. A plasma condition to obtain a desired selectivity may then be appropriately set using the established correlation.
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Citations
32 Claims
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1. A dry etching method for etching silicon material layers by using plasma of a gas mixture including oxygen and at least one halogen/halide, the method including the steps of:
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measuring intensities of a first emission from the plasma at a first wavelength and a second emission from the plasma at a second wavelength; obtaining a ratio of the intensity of the first emission to that of the second emission; measuring selectivity of silicon material layers to an oxide layer formed over a substrate for a condition of the plasma for which the emission intensity ratio is obtained; obtaining a correlation between the emission intensity ratio and the selectivity; and setting a plasma condition for a desired selectivity based on a measured emission intensity ratio by using the correlation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 11, 12, 13, 21)
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9. A dry etching method for etching silicon material layers formed on oxide underlayers by using organic resist masks in a plasma of a gas mixture including oxygen and at least one halogen/halide, the method including the steps of:
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measuring intensities of a first emission from the plasma at a first wavelength and a second emission from the plasma at a second wavelength; obtaining a ratio of the intensity of the first emission to that of the second emission, measuring selectivity of silicon material layers to an oxide layer formed over a substrate for a condition of the plasma for which the emission intensity ratio is obtained; obtaining a correlation between the emission intensity ratio and the selectivity; and controlling a condition of the plasma based on the emission intensity ratio. - View Dependent Claims (10, 14, 15, 16, 17, 18, 19, 20)
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22. A dry etching method for etching silicon material layers by using a gas mixture including halogen/halide gas and oxygen gas, the method including the steps of:
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generating a magnetic field and introducing microwaves for producing plasma of the gas mixture;
whereinthe oxygen gas is introduced into a first region of the magnetic field while the halogen/halide gas is introduced into a second region of the magnetic field which is different from the first region; the oxygen gas is excited into a first plasma in the first region having an plasma density higher than that of a second plasma of the second region wherein the halogen/halide gas excited into a second plasma. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A dry etching method for etching silicon material layers in a reaction chamber by using a gas mixture including halogen/halide gas and oxygen gas, the method including the steps of:
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exciting the oxygen gas in a first region to produce a first plasma; introducing the halogen/halide gas into a second region and exciting the halogen/halide gas to generate a second plasma, wherein the first region has a plasma density higher than the second region; and mixing the first plasma into the second plasma;
thereby increasing plasma density of oxygen radicals to halogen/radicals in the reaction chamber. - View Dependent Claims (30, 31, 32)
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Specification