Tokyo Electron Limited

Université D'orleans

Du Zhang

Mingmei Wang

Yu-Hao Tsai

Yoshihide Kihara

Masahiko Yokoi

Shigeru Tahara

Andrew W Metz

Jacques Faguet

Aelan Mosden

Kaoru Maekawa

Shihsheng Chang

Takatoshi Orui

Koki Tanaka

Yunho Kim

Matthew Flaugh

Hojin Kim

Remi Dussart

Thomas Tillocher

Philippe Lefaucheux

Gaëlle Antoun

Christophe Vallee

Motoi Takahashi

Embodiments of improved processes and methods that provide selective etching of silicon nitride are disclosed herein. More specifically, a cyclic, two-step dry etch process is provided to selectively etch silicon nitride layers formed on a substrate, while protecting oxide layers formed on the same substrate. The cyclic, two-step dry etch process sequentially exposes the substrate to: (1) a hydrogen plasma to modify exposed surfaces of the silicon nitride layer and the oxide layer to form a modified silicon nitride surface layer and a modified oxide surface layer, and (2) a halogen plasma to selectively etch silicon nitride by removing the modified silicon nitride surface layer without removing the modified oxide surface layer. The oxide layer is protected from etching during the removal step (i.e., step 2) by creating a crystallized water layer on the oxide layer during the surface modification step (i.e., step 1).

Method to selectively etch silicon nitride to silicon oxide using water crystallization

A method of processing a substrate includes patterning a mask over a dielectric layer and etching openings in the dielectric layer. The dielectric layer is disposed over the substrate. The etching includes flowing an etchant, a polar or H-containing gas, and a phosphorus-halide gas. The method may further include forming contacts by filling the openings with a conductive material.

Method for etching for semiconductor fabrication

A method of processing a substrate that includes: flowing dioxygen (O) and an adsorbate precursor into a plasma processing chamber that is configured to hold the substrate including an organic layer and a patterned etch mask; sustaining an oxygen-rich plasma while flowing the Oand the adsorbate precursor, oxygen species from the Oand the adsorbate precursor reacting under the oxygen-rich plasma to form an adsorbate; and exposing the substrate to the oxygen-rich plasma to form a recess in the organic layer, where the adsorbate forms a sidewall passivation layer in the recess.

In-situ adsorbate formation for plasma etch process

A method of processing a substrate that includes: loading the substrate in a plasma processing chamber, the substrate having a surface including an oxide, the oxide including an alkaline earth metal; flowing a process gas including CClinto the plasma processing chamber; in the plasma processing chamber, forming a fluorine-free plasma from the process gas by applying a source power to a source electrode of the plasma processing chamber; and exposing the substrate to the fluorine-free plasma to etch the oxide of the surface.

Etch process for oxide of alkaline earth metal

A method for processing a substrate that includes: loading the substrate in a plasma processing chamber; performing a cyclic plasma etch process including a plurality of cycles, where each cycle of the plurality of cycles includes: generating a first plasma from a first gas mixture including a fluorosilane and oxygen; performing a deposition step by exposing the substrate to the first plasma to form a passivation film including silicon and fluorine; generating a second plasma from a second gas mixture including a noble gas; and performing an etch step by exposing the substrate to the second plasma.

Selective etching with fluorine, oxygen and noble gas containing plasmas

A method of high-throughput dry etching of a film by proton-mediated catalyst formation. The method includes providing a substrate having a film thereon containing silicon-oxygen components, silicon-nitrogen components, or both, introducing an etching gas in the process chamber, plasma-exciting the etching gas, and exposing the film to the plasma-excited etching gas to etch the film. In one example, the etching gas contains at least three different gases that include a fluorine-containing gas, a hydrogen-containing gas, and a nitrogen-containing gas, plasma-exciting the etching gas. In another example, the etching gas contains at least four different gases that include a fluorine-containing gas, a hydrogen-containing gas, an oxygen-containing gas, and a silicon-containing gas.

High-throughput dry etching of films containing silicon-oxygen components or silicon-nitrogen components by proton-mediated catalyst formation

A method for processing a substrate includes performing a cyclic process including a plurality of cycles, where the cyclic process includes: forming, in a plasma processing chamber, a passivation layer over sidewalls of a recess in a carbon-containing layer, by exposing the substrate to a first gas including boron, silicon, or aluminum, the carbon-containing layer being disposed over a substrate, purging the plasma processing chamber with a second gas including a hydrogen-containing gas, an oxygen-containing gas, or molecular nitrogen, and exposing the substrate to a plasma generated from the second gas, where each cycle of the plurality of cycles extends the recess vertically into the carbon-containing layer.

Cyclic plasma etching of carbon-containing materials

Methods for the atomic layer etch (ALE) of tungsten or other metal layers are disclosed that use in part sequential oxidation and reduction of tungsten/metal layers to achieve target etch parameters. For one embodiment, a metal layer is first oxidized to form a metal oxide layer and an underlying metal layer. The metal oxide layer is then reduced to form a surface metal layer and an underlying metal oxide layer. The surface metal layer is then removed to leave the underlying metal oxide layer and the underlying metal layer. Further, the oxidizing, reducing, and removing processes can be repeated to achieve a target etch depth. In addition, a target etch rate can also achieved for each process cycle of oxidizing, reducing, and removing.

Atomic layer etch (ALE) of tungsten or other metal layers

A method for selective plasma etching of silicon oxide relative to silicon nitride. The method includes a) providing a substrate containing a silicon oxide film and a silicon nitride film, b) exposing the substrate to a plasma-excited treatment gas containing 1) Hand 2) HF, F, or both HF and F, to form a silicon oxide surface layer with reduced oxygen content on the silicon oxide film and form an ammonium salt layer on the silicon nitride film, c) exposing the substrate to a plasma-excited halogen-containing gas that reacts with and removes the silicon oxide surface layer from the silicon oxide film, and d) repeating steps b) and c) at least once to further selectively etch the silicon oxide film relative to the ammonium salt layer on the silicon nitride film. The ammonium salt layer may be removed when the desired etching has been achieved.

Selective plasma etching of silicon oxide relative to silicon nitride by gas pulsing

A method for selective etching of silicon oxide relative to silicon nitride includes exposing a substrate to a first gas that forms a first layer on the silicon oxide film and a second layer on the silicon nitride film, where the first gas contains boron, aluminum, or both boron and aluminum, exposing the substrate to a nitrogen-containing gas that reacts with the first layer to form a first nitride layer on the silicon oxide film and reacts with the second layer to form a second nitride layer on the silicon nitride film, where a thickness of the second nitride layer is greater than a thickness of the first nitride layer. The method further includes exposing the substrate to an etching gas that etches the first nitride layer and silicon oxide film, where the second nitride layer protects the silicon nitride film from etching by the etching gas.

Highly selective silicon oxide/silicon nitride etching by selective boron nitride or aluminum nitride deposition

A method for selective plasma etching of silicon oxide relative to silicon nitride is described. The method includes providing a substrate containing a silicon oxide film and a silicon nitride film, and selectively etching the silicon oxide film relative to the silicon nitride film by: a1) exposing the substrate to a plasma-excited passivation gas containing carbon, sulfur, or both carbon and sulfur, where the plasma-excited passivation gas does not contain fluorine or hydrogen, and b1) exposing the substrate to a plasma-excited etching gas containing a fluorine-containing gas. The method can further include, between a1) and b1), an additional step of a2) exposing the substrate to a plasma-excited additional passivation gas containing a fluorocarbon gas, hydrofluorocarbon gas, a hydrochlorocarbon gas, a hydrochlorofluorocarbon gas, or a hydrocarbon gas, or a combination thereof.

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Albany, NY, United States of America

Du Zhang