Partial photoresist etching
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsMing-Ching Chang, Hun-Jan Tao
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Abstract
Partial photoresist etching is disclosed. A film on a semiconductor wafer includes a hard mask, doped polysilicon below the hard mask, undoped polysilicon below the doped polysilicon, and a stop layer below the undoped polysilicon. Photoresist etching is performed through the hard mask and the doped polysilicon by using a photoresist mask. After the photoresist mask is removed, photoresist-free etching is performed through the undoped polysilicon through to the stop layer by using the hard mask. A semiconductor device is disclosed that may be fabricated using this partial photoresist etching process.
Claims14
A method comprising:
- etching a hard mask layer and a doped polysilicon layer below the hard mask layer of a film on a semiconductor wafer also including an undoped polysilicon layer below the doped polysilicon layer, using a photoresist mask above the hard mask layer to impart a pattern through the hard mask layer and the doped polysilicon layer;
- removing the photoresist mask from above the hard mask layer of the film on the semiconductor wafer;
- and,
- etching the undoped polysilicon layer of the film on the semiconductor wafer, using the hard mask to impart the pattern through the undoped polysilicon layer.
A method comprising:
- photoresist dry etching of at least one but not all of a plurality of layers, including photoresist dry etching at least a first polysilicon layer, on a semiconductor wafer to impart a pattern through the at least one but not all of the plurality of layers;
- removing photoresist from the plurality of layers;
- and,
- photoresist-free dry etching of the plurality of layers remaining after the photoresist dry etching of the at least one but not all of the plurality of layers to impart the pattern through the plurality of layers remaining, including photoresist-free dry etching at least a second polysilicon layer under the first polysilicon layer.
Dependencies are inferred from the claim text.