Lam Research Corporation

Sm Reza Sadjadi

Jisoo Kim

Sangheon Lee

Robert Charatan

Zhisong Huang

Peter Cirigliano

Dongho Heo

Binet A Worsham

Supriya Goyal

Dae-han Choi

A method for etching a dielectric layer is provided. A patterned mask with mask features is formed over a dielectric layer. The mask has isolated areas and dense areas of the mask features. The mask is trimmed by a plurality of cycles, where each cycle includes depositing a deposition layer, and selectively etching the deposition layer and the patterned mask. The selective etching selectively trims the isolated areas of the mask with respect to the dense areas of the mask. The dielectric layer is etched using the thus trimmed mask. The mask is removed.

Mask trimming

A method for forming a feature in an etch layer is provided. A photoresist layer is formed over the etch layer. The photoresist layer is patterned to form photoresist features with photoresist sidewalls. A control layer is formed over the photoresist layer and bottoms of the photoresist features. A conformal layer is deposited over the sidewalls of the photoresist features and control layer to reduce the critical dimensions of the photoresist features. Openings in the control layer are opened with a control layer breakthrough chemistry. Features are etched into the etch layer with an etch chemistry, which is different from the control layer break through chemistry, wherein the control layer is more etch resistant to the etch with the etch chemistry than the conformal layer.

Critical dimension reduction and roughness control

A method for etching a dielectric layer over a substrate is provided. A photoresist mask is formed over the dielectric layer. The substrate is placed in a plasma processing chamber. An etchant gas comprising NFis provided into the plasma chamber. A plasma is formed from the NFgas. The dielectric layer is etched through the photoresist mask with the plasma from the NFgas.

Etch with photoresist mask

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Saratoga, CA, United States of America

Sm Reza Sadjadi