Line edge roughness improvement with sidewall sputtering
AssigneeLam Research Corporation
InventorsZhongkui Tan, Hua Xiang, Yiting Zhang, Qian Fu, Qing Xu
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Abstract
A method for reducing sidewall roughness in an etch layer below a first mask with sidewall roughness in a processing chamber is provided. Sidewalls of the first mask are smoothed, comprising, flowing a processing gas into the processing chamber and forming the processing gas into an in situ plasma in the processing chamber with sufficient energy to sputter and smooth sidewall roughness of the first patterned mask. The etch layer is etched through the first patterned mask.
Claims18
A method for reducing sidewall roughness in an etch layer below a first mask with sidewall roughness in a processing chamber, wherein a second mask is over the first mask, comprising:
- transferring a pattern from the second mask to the first mask forming a sidewall roughness in the first mask, wherein the first mask has a first sputter threshold voltage (V1) and wherein the transferring the pattern from the second mask to the first mask creates a damaged sidewall surface on the first mask, wherein the damaged sidewall surface has a second sputter threshold voltage (V2), wherein V1>V2;
- smoothing sidewalls of the first mask, comprising:
- flowing a processing gas into the processing chamber;
- and
- forming the processing gas into an in situ plasma in the processing chamber with sufficient energy to sputter and smooth sidewall roughness of the first mask, wherein a bias voltage between about V1 and V2 is provided during the smoothing the sidewalls;
- and
- etching the etch layer through the first mask.
Dependencies are inferred from the claim text.