Method and system for reducing line edge roughness during pattern etching
AssigneeTokyo Electron Limited
InventorMasafumi URAKAWA
Life of this patent
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Abstract
A method of mitigating pattern defects, such as critical dimension (CD) bias and line-edge roughness (LER), during a pattern transfer process is described. The method comprises forming one or more layers on a substrate, forming a radiation sensitive mask layer on the one or more layers, and forming a pattern in the radiation sensitive mask layer using a lithographic process. Once the pattern is formed, the edges of the pattern are smoothed by exposing the pattern in the radiation sensitive mask layer to a fluorohydrocarbon-containing plasma. Thereafter, the smoothed pattern in the radiation sensitive mask layer is transferred to one or more of the one or more layers using one or more etching processes.
Claims20
A method of mitigating pattern defects in a pattern transfer process, comprising:
- forming one or more layers on a substrate;
- forming a radiation sensitive mask layer on said one or more layers;
- forming a pattern in said radiation sensitive mask layer using a lithographic process;
- smoothing edges of said pattern by exposing said pattern in said radiation sensitive mask layer to a fluorohydrocarbon-containing plasma;
- and
- transferring said smoothed pattern in said radiation sensitive mask layer to one or more of said one or more layers using one or more etching processes.
A method of performing a pattern transfer process, comprising:
- forming a film stack on a substrate, said film stack comprising a polysilicon layer, a hard mask layer formed on said polysilicon layer, and an anti-reflective coating (ARC) layer formed on said hard mask layer, and a radiation sensitive mask layer formed on said ARC layer;
- forming a pattern in said radiation sensitive mask layer using a lithographic process;
- trimming a lateral dimension of said pattern in said radiation sensitive layer;
- transferring said trimmed pattern to said ARC layer using a first etching process;
- smoothing the edges of said trimmed pattern by exposing said trimmed pattern in said radiation sensitive mask layer to a fluorohydrocarbon-containing plasma;
- transferring said smoothed pattern in said radiation sensitive mask layer and said ARC layer to said hard mask layer using a second etching process;
- and
- transferring said smoothed pattern in said hard mask layer to said polysilicon layer using a third etching process.
Dependencies are inferred from the claim text.