Dry-etch selectivity
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 nitride region and an exposed second material region, the method comprising:
- flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a plasma in the plasma region to produce plasma effluents;
pulsing a power of the plasma at a plasma frequency with a plasma duty cycle;
flowing the plasma effluents through a showerhead separating the remote plasma region from the substrate processing region; and
etching the exposed silicon nitride region, wherein the substrate processing region is maintained substantially plasma free during the etching operation, and wherein the patterned substrate is maintained substantially unbiased during the etching operation.
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Abstract
A method of etching exposed patterned heterogeneous structures is described and includes a remote plasma etch formed from a reactive precursor. The plasma power is pulsed rather than left on continuously. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents selectively remove one material faster than another. The etch selectivity results from the pulsing of the plasma power to the remote plasma region, which has been found to suppress the number of ionically-charged species that reach the substrate. The etch selectivity may also result from the presence of an ion suppression element positioned between a portion of the remote plasma and the substrate processing region.
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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 nitride region and an exposed second material region, the method comprising:
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flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a plasma in the plasma region to produce plasma effluents; pulsing a power of the plasma at a plasma frequency with a plasma duty cycle; flowing the plasma effluents through a showerhead separating the remote plasma region from the substrate processing region; and etching the exposed silicon nitride region, wherein the substrate processing region is maintained substantially plasma free during the etching operation, and wherein the patterned substrate is maintained substantially unbiased during the etching operation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of etching a patterned substrate in a substrate processing region of a semiconductor processing chamber, the method comprising:
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flowing a first precursor into a remote plasma region of a semiconductor processing chamber separated from the substrate processing region by a showerhead; pulsing a power for a plasma generated within the remote plasma region; etching the patterned substrate with plasma effluents produced by the pulsed plasma, wherein the patterned substrate is maintained substantially unbiased during the etching operation. - View Dependent Claims (20)
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Specification