Forming semiconductor device by providing an amorphous silicon core with a hard mask layer
First Claim
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1. A method of forming a semiconductor device comprising:
- patterning a substrate, wherein patterning the substrate comprises;
providing a lower amorphous silicon layer on the substrate, wherein the lower amorphous silicon layer is provided with an anti-crystallization dopant;
forming an upper hard mask layer above the lower silicon layer;
forming openings in the upper hard mask layer, the openings exposing portions of the lower amorphous silicon layer;
anisotropically etching the lower amorphous silicon layer through the openings in the upper hard mask layer to define a patterned lower amorphous silicon layer;
removing the upper hard mask layer;
depositing a conformal layer on the patterned lower amorphous silicon layer;
anisotropically etching the second conformal layer to leave vertical portions of the second conformal layer along sidewalls of the patterned lower amorphous silicon layer; and
removing the lower amorphous silicon layer while retaining the vertical portions of the second conformal layer.
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Abstract
The invention relates to a method of forming a semiconductor device by patterning a substrate by providing an amorphous silicon layer on the substrate and forming a hard mask layer on the amorphous silicon layer. The amorphous silicon layer is provided with an anti-crystallization dopant to keep the layer amorphous at increased temperatures (relative to not providing the anti-crystallization dopant). The hard mask layer may comprise silicon and nitrogen.
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21 Claims
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1. A method of forming a semiconductor device comprising:
patterning a substrate, wherein patterning the substrate comprises; providing a lower amorphous silicon layer on the substrate, wherein the lower amorphous silicon layer is provided with an anti-crystallization dopant; forming an upper hard mask layer above the lower silicon layer; forming openings in the upper hard mask layer, the openings exposing portions of the lower amorphous silicon layer; anisotropically etching the lower amorphous silicon layer through the openings in the upper hard mask layer to define a patterned lower amorphous silicon layer; removing the upper hard mask layer; depositing a conformal layer on the patterned lower amorphous silicon layer; anisotropically etching the second conformal layer to leave vertical portions of the second conformal layer along sidewalls of the patterned lower amorphous silicon layer; and removing the lower amorphous silicon layer while retaining the vertical portions of the second conformal layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21)
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20. A method of forming a semiconductor device, comprising:
patterning a substrate, wherein patterning the substrate comprises, in order; forming a lower hard mask layer on the substrate; providing a lower amorphous silicon layer above the lower hard mask layer, the lower amorphous silicon layer comprising an anti-crystallization dopant; forming an upper hard mask layer above the lower amorphous silicon layer by a method comprising heating the substrate to a temperature above 550°
C.;providing an upper amorphous silicon layer above the upper hard mask layer; providing a photoresist film above the upper amorphous silicon layer; exposing and developing the photoresist film to form a photoresist pattern; anisotropically etching the photoresist pattern into the upper amorphous silicon layer; depositing a first conformal layer over exposed surfaces and over the substrate; anisotropically etching the first conformal layer to remove horizontal portions of the first conformal layer while leaving vertical portions of the first conformal layer at sidewalls of patterned features in the upper amorphous silicon layer; removing the upper amorphous silicon layer; anisotropically etching the upper hard mask through open portions between the vertical portions of the first conformal layer; removing remaining portions of the first conformal layer; anisotropically etching the lower amorphous silicon layer through open portions of the upper hard mask layer; removing the upper hard mask layer; depositing a second conformal layer over exposed surfaces at the surface of the substrate; anisotropically etching the second conformal layer to remove the horizontal portions of the second conformal layer while leaving the vertical portions of the second conformal layer; removing the lower amorphous silicon layer; anisotropically etching the lower hard mask through open portions between the vertical portions of the second conformal layer; removing remaining portions of the second conformal layer; and anisotropically etching the substrate through open portions of the lower hard mask layer.
Specification