Quasi self-aligned source/drain FinFET process
First Claim
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1. A method of forming a semiconductor structure comprising:
- providing a structure including a plurality of patterned material stacks comprising a nitride layer on top of an oxide hardmask on a surface of semiconductor substrate and a plurality of patterned photomasks which cross over said plurality of patterned material stacks;
performing a chemical oxide removal step that laterally etches at least exposes sidewalls of said oxide hardmask of each material stack not protected by one of said patterned photomasks;
removing the plurality of patterned photomasks to expose patterned material stacks including a laterally etched oxide hardmask beneath said nitride layer;
performing an anisotropic etching process selective to the laterally etched oxide hardmask to remove said nitride layer and at least an upper portion of any semiconducting material of said semiconductor substrate not protected by said laterally etched oxide hardmask thereby forming Fins; and
forming a plurality of gate regions that cross over said Fins.
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Abstract
A method of forming a semiconductor structure including a plurality of finFFET devices in which crossing masks are employed in providing a rectangular patterns to define relatively thin Fins along with a chemical oxide removal (COR) process is provided. The present method further includes a step of merging adjacent Fins by the use of a selective silicon-containing material. The present invention also relates to the resultant semiconductor structure that is formed utilizing the method of the present invention.
145 Citations
11 Claims
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1. A method of forming a semiconductor structure comprising:
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providing a structure including a plurality of patterned material stacks comprising a nitride layer on top of an oxide hardmask on a surface of semiconductor substrate and a plurality of patterned photomasks which cross over said plurality of patterned material stacks; performing a chemical oxide removal step that laterally etches at least exposes sidewalls of said oxide hardmask of each material stack not protected by one of said patterned photomasks; removing the plurality of patterned photomasks to expose patterned material stacks including a laterally etched oxide hardmask beneath said nitride layer; performing an anisotropic etching process selective to the laterally etched oxide hardmask to remove said nitride layer and at least an upper portion of any semiconducting material of said semiconductor substrate not protected by said laterally etched oxide hardmask thereby forming Fins; and forming a plurality of gate regions that cross over said Fins. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of forming a semiconductor structure comprising:
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providing a plurality of patterned material stacks comprising a nitride layer on top of an oxide hardmask on a surface of top semiconducting layer of an SOI substrate and a plurality of patterned photomasks which cross over said plurality of patterned material stacks; performing a chemical oxide removal step which laterally etches at least exposes sidewalls said oxide hardmask of each material stack not protected by one of said patterned photomasks; removing the plurality of patterned photomasks to expose patterned material stacks including a laterally etched oxide hardmask beneath said nitride layer; performing an anisotropic etching process selective to the laterally etched oxide hardmask to remove said nitride layer and at least said top semiconducting layer of the SOI substrate not protected by said laterally etched oxide hardmask, stopping on a buried insulating layer of said SOI substrate; removing said laterally etched oxide hardmask exposing upper portions of the top semiconducting layer of the SOI substrate previously protected by said laterally etched oxide hardmask as well as exposed portions of the buried insulating layer, wherein portions of said exposed top semiconducting layer of the SOI substrate previously protected by said laterally etched oxide hardmask defines Fins; and forming a plurality of gate regions which cross over said Fins. - View Dependent Claims (10, 11)
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Specification