Lam Research Corporation

Andrew Clark Serino

Eric A Hudson

Nerissa Sue Draeger

Leonid Belau

Youn-Jin Oh

Chia-Chun Wang

Yilun Li

Wonjae Lee

Zhonghao Zhang

Rui Takahashi

Various embodiments herein relate to methods and apparatus for etching recessed features on a semiconductor substrate. The techniques described herein can be used to form high quality recessed features with a substantially vertical profile, low bowing, low twisting, and highly circular features. These high quality results can be achieved with a high degree of selectivity and a relatively high etch rate. In various embodiments, etching involves exposing the substrate to plasma generated from a processing gas that includes a chlorine source, a carbon source, a hydrogen source, and a fluorine source. The chlorine source may have particular properties. In some cases, particular chlorine sources may be used. Etching typically occurs at low temperatures, for example at about 25 C or lower.

High aspect ratio dielectric etch with chlorine

A method for selectively etching a dielectric layer with respect to an epitaxial layer or metal-based hardmask is provided. The method comprises performing a plurality of cycles. Each cycle comprises a deposition phase and an activation phase. The deposition phase comprises flowing a deposition gas, wherein the deposition gas comprises helium and a hydrofluorocarbon or fluorocarbon, forming the deposition gas into a plasma to effect a fluorinated polymer deposition, and stopping the flow of the deposition gas. The activation phase comprises flowing an activation gas comprising an ion bombardment gas, forming the activation gas into a plasma, providing an activation bias to cause ion bombardment of the fluorinated polymer deposition, wherein the ion bombardment activates fluorine from the fluorinated polymer deposition to etch the dielectric layer, and stopping the flow of the activation gas.

Selective atomic layer etching

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Livermore, CA, United States of America

Andrew Clark Serino