SELECTIVE SUPPRESSION OF DRY-ETCH RATE OF MATERIALS CONTAINING BOTH SILICON AND OXYGEN
First Claim
1. A method of etching a patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned substrate has an exposed silicon-and-oxygen-containing region and an exposed region of a second material having a different chemical stoichiometry from the exposed silicon-and-oxygen-containing region, the method of etching the patterned substrate comprising sequential steps of:
- (1) a first dry etch stage comprising;
flowing each of a first fluorine-containing precursor and a hydrogen-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a first plasma in the remote plasma region to produce first plasma effluents, andforming protective solid by-product on the exposed silicon-and-oxygen-containing region to form a protected silicon-and-oxygen-containing region, wherein forming the protective solid by-product comprises flowing the first plasma effluents into the substrate processing region in a showerhead;
(2) a second dry etch stage comprisingflowing a second fluorine-containing precursor into the remote plasma region while forming a second plasma in the remote plasma region to produce second plasma effluents, andetching the exposed region of the second material faster than the protected silicon-and-oxygen-containing region by flowing the second plasma effluents into the substrate processing region through through-holes in the showerhead; and
(3) sublimating the protective solid by-product from the protected silicon-and-oxygen-containing region by raising a temperature of the patterned substrate.
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Abstract
A method of suppressing the etch rate for exposed silicon-and-oxygen-containing material on patterned heterogeneous structures is described and includes a two stage remote plasma etch. Examples of materials whose selectivity is increased using this technique include silicon nitride and silicon. The first stage of the remote plasma etch reacts plasma effluents with the patterned heterogeneous structures to form protective solid by-product on the silicon-and-oxygen-containing material. The plasma effluents of the first stage are formed from a remote plasma of a combination of precursors, including a nitrogen-containing precursor and a hydrogen-containing precursor. The second stage of the remote plasma etch also reacts plasma effluents with the patterned heterogeneous structures to selectively remove material which lacks the protective solid by-product. The plasma effluents of the second stage are formed from a remote plasma of a fluorine-containing precursor.
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Citations
20 Claims
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1. A method of etching a patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned substrate has an exposed silicon-and-oxygen-containing region and an exposed region of a second material having a different chemical stoichiometry from the exposed silicon-and-oxygen-containing region, the method of etching the patterned substrate comprising sequential steps of:
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(1) a first dry etch stage comprising; flowing each of a first fluorine-containing precursor and a hydrogen-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a first plasma in the remote plasma region to produce first plasma effluents, and forming protective solid by-product on the exposed silicon-and-oxygen-containing region to form a protected silicon-and-oxygen-containing region, wherein forming the protective solid by-product comprises flowing the first plasma effluents into the substrate processing region in a showerhead; (2) a second dry etch stage comprising flowing a second fluorine-containing precursor into the remote plasma region while forming a second plasma in the remote plasma region to produce second plasma effluents, and etching the exposed region of the second material faster than the protected silicon-and-oxygen-containing region by flowing the second plasma effluents into the substrate processing region through through-holes in the showerhead; and (3) sublimating the protective solid by-product from the protected silicon-and-oxygen-containing region by raising a temperature of the patterned substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification