Lam Research Corporation

Dongho Heo

S M Reza Sadjadi

Jisoo Kim

Supriya Goyal

Ji Soo Kim

Sangheon Lee

Peter Cirigliano

Daehan Choi

Sm Reza Sadjadi

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 etching features in a dielectric layer through a photoresist (PR) mask is provided. The PR mask is patterned using laser light having a wavelength not more than 193 nm. The PR mask is pre-treated with a noble gas plasma, and then a plurality of cycles of a plasma process is provided. Each cycle includes a deposition phase that deposits a deposition layer over the PR mask, the deposition layer covering a top and sidewalls of mask features of the PR mask, and a shaping phase that shapes the deposition layer deposited over the PR mask.

Plasma process with photoresist mask pretreatment

A feature in a layer is provided. A photoresist layer is formed over the layer. The photoresist layer is patterned to form photoresist features with photoresist sidewalls, where the photoresist features have a first critical dimension. A fluorine-containing conformal layer is deposited over the sidewalls of the photoresist features to reduce the critical dimensions of the photoresist features. Fluorine is removed from the conformal layer, while the remaining conformal layer is left in place. Features are etched into the layer, wherein the layer features have a second critical dimension, which is less than the first critical dimension.

De-fluoridation process

A method for etching features into an etch layer disposed below a photoresist mask without an intermediate hardmask is provided. A plurality of etch cycles are provided. Each etch cycle comprises providing a deposition etch phase that etches features into the etch layer and deposits polymer on sidewalls of the features and over the photoresist and providing a cleaning phase that removes polymer deposited on the sidewalls.

Infinitely selective photoresist mask etch

A method for etching a dielectric layer disposed below an antireflection layer (ARL) is provided. The method comprises (a) forming a patterned mask with mask features over the ARL, the mask having isolated areas and dense areas of the mask features, (b) trimming and opening, and (c) etching the dielectric layer using the trimmed mask. The trimming and opening comprises a plurality of cycles, where each cycle includes (b1) a trim-etch phase which etches the ARL in a bottom of the mask features and selectively trims the isolated areas of the mask with respect to the dense areas, and (b2) a deposition-etch phase which deposits a deposition layer on the mask while further etching the ARL in the bottom of the mask features. The trimming and opening result in a net trimming of the mask in the isolated areas.

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Fremont, CA, United States of America

Dongho Heo