Tokyo Electron Limited

Yu-Hao Tsai

Mingmei Wang

Du Zhang

Yoshihide Kihara

Aelan Mosden

Hamed Hajibabaeinajafabadi

Matthew Flaugh

Masahiko Yokoi

Angelique Denise Raley

Akiteru Ko

Sergey Alexandrovich Voronin

Subhadeep Kal

Katie Lutker-Lee

Takatoshi Orui

Koki Tanaka

Pingshan Luan

Jonathan Hollin

Motoi Takahashi

Jake Kaminsky

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 includes receiving a substrate including a photoresist film including exposed and unexposed portions, etching parts of the unexposed portions of the photoresist film with a developing gas in a process chamber to leave a residual part of the unexposed portions, and purging the developing gas from the process chamber with a purging gas. After purging the developing gas, the residual part of the unexposed portions is etched with the developing gas. The substrate is etched using exposed portions of the photoresist film as a mask.

Cyclic method for reactive development of photoresists

Selective protection and etching is provided which can be utilized in etching of a silicon containing layer with respect to a Ge or SiGe layer. In an example, the layers are stacked, and an oxide is on a side surface of the layers. A treatment is utilized to provide a modified surface or termination surface on side surfaces of the Ge/SiGe layers, and a heat treatment is provided after the gas treatment to selectively sublimate layer portions on side surfaces of the Si containing layers. The gas treatment and heat treatment are preferably in non-plasma environments. Thereafter, a plasma process is performed to form a protective layer on the Ge containing layers, and the Si containing layers can be etched with the plasma.

Selective and isotropic etch of silicon over silicon-germanium alloys and dielectrics; via new chemistry and surface modification

A method of forming a semiconductor device includes depositing a first layer over a substrate and patterning the first layer using an extreme ultraviolet (EUV) lithography process to form a patterned layer and expose portions of the substrate. The method includes, in a plasma processing chamber, generating a first plasma from a gas mixture including SiCl4 and one or more of argon, helium, nitrogen, and hydrogen. The method includes exposing the substrate to the first plasma to deposit a second layer including silicon over the patterned layer.

Methods of patterning small features

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

Substrate processing techniques are described in which an etch protection layer that is formed as part of an etch process forms in a self-limiting nature. Thus, over deposition effects are minimized, particularly in the corners of etched polygonal holes. In one embodiment, the layer being etched contains silicon and the protective layer comprises a silicon oxide (SixOy). The process may include the use of a cyclical series of etch and protective layer formation steps. In the case of a silicon oxide based protective layer, a thin protective layer of silicon oxide may be formed in a limiting and controllable manner due to the nature of the oxygen atom interaction with silicon and newly formed silicon oxide protective layers. In this manner, a polygonal hole may be formed without detrimental over deposition of a protective layer in corners of the hole.

Sidewall protection layer formation for substrate processing

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

Yu-Hao Tsai