KR-20260066653-A - Systems and methods for selective removal of metal-containing hard masks

Abstract

Exemplary semiconductor processing methods may include the step of flowing an etching agent precursor into a processing area of a semiconductor processing chamber. A substrate may be accommodated within the processing area. The substrate may define an exposed area of a metal-containing hard mask material and an exposed area of a material characterized by a dielectric constant of about 4.0 or less. The methods may include the step of bringing the substrate into contact with the etching agent precursor. The methods may include the step of removing at least a portion of the metal-containing hard mask material.

Inventors

• 왕, 바이웨이
• 레디, 로한 풀리고루
• 천, 샤오린 씨.
• 쉬, 완싱
• 추이, 전장
• 왕, 안촨

Assignees

• 어플라이드 머티어리얼스, 인코포레이티드

Dates

Publication Date

20260512

Application Date

20240830

Priority Date

20230911

Claims (20)

1. As a semiconductor processing method, A step of flowing an etching agent precursor into a processing area of a semiconductor processing chamber—a substrate is accommodated within the processing area, wherein the substrate defines an exposed area of a metal-containing hard mask material and an exposed area of a material characterized by a dielectric constant of about 4.0 or less—; A step of contacting the substrate with the etching agent precursor; and A semiconductor processing method comprising the step of removing at least a portion of the metal-containing hard mask material.
2. A semiconductor processing method according to claim 1, wherein the etching agent precursor comprises a halogen-containing precursor.
3. A semiconductor processing method according to claim 1, wherein the etching agent precursor comprises nitrogen trifluoride ( NF₃ ), diatomic fluorine ( F₂ ), diatomic chlorine ( Cl₂ ), thionyl chloride ( SOCl₂ ), carbon tetrafluoride ( CF₄ ), hexafluoroethane ( C₂F₆ ), sulfur hexafluoride ( SF₆ ), carbon tetrachloride ( CCl₄ ), dichloromethane ( CH₂Cl₂ ), chloroform ( CHCl₃ ), or a combination thereof.
4. A semiconductor processing method according to claim 1, wherein the etching agent precursor comprises nitrogen trifluoride ( NF3 ).
5. In paragraph 1, A semiconductor processing method further comprising the step of flowing a hydrogen-containing precursor or an oxygen-containing precursor into a processing area of the semiconductor processing chamber together with the etching agent precursor.
6. A semiconductor processing method according to claim 1, wherein the step of removing a portion of the metal-containing hard mask material is performed without plasma.
7. A semiconductor processing method according to claim 1, wherein the step of removing a portion of the metal-containing hard mask material is performed at a temperature of about 350°C or higher.
8. A semiconductor processing method according to claim 1, wherein the step of removing a portion of the metal-containing hard mask material is performed at a pressure of about 2 Torr or more.
9. In paragraph 1, A semiconductor processing method further comprising the step of removing an oxidized portion of a metal-containing hard mask material before flowing the etching agent precursor into a processing area of the semiconductor processing chamber.
10. In paragraph 1, A semiconductor processing method comprising, following the step of removing a portion of the metal-containing hard mask material, further a step of contacting the substrate with a second etching agent precursor to remove a fluorine-containing residue from the substrate or the oxidized portion of the metal-containing hard mask material.
11. As a semiconductor processing method, A step of flowing a pre-etching precursor into a processing area of a semiconductor processing chamber—a substrate is accommodated within the processing area, said substrate defines an exposed area of a metal-containing hard mask material and an exposed area of a material characterized by a dielectric constant of about 4.0 or less—; A step of contacting the above substrate with the above pre-etching precursor; A step of stopping the delivery of the above-mentioned pre-etching precursor; A step of flowing an etching agent precursor into a processing area of the semiconductor processing chamber; A step of contacting the substrate with the etching agent precursor; and A semiconductor processing method comprising the step of selectively removing at least a portion of the metal-containing hard mask material relative to the material characterized by a dielectric constant of about 4.0 or less.
12. A semiconductor processing method according to claim 11, wherein the pre-etching precursor comprises nitrogen trifluoride ( NF₃ ), tungsten hexafluoride ( WF₆ ), or boron trichloride ( BCl₃ ).
13. In Paragraph 11, A semiconductor processing method further comprising the step of forming plasma effluents of the above-mentioned pre-etching precursor.
14. A semiconductor processing method according to claim 11, wherein the etching agent precursor comprises nitrogen trifluoride ( NF₃ ), diatomic fluorine ( F₂ ), diatomic chlorine ( Cl₂ ), thionyl chloride ( SOCl₂ ), carbon tetrafluoride ( CF₄ ), hexafluoroethane ( C₂F₆ ), sulfur hexafluoride ( SF₆ ), carbon tetrachloride ( CCl₄ ), dichloromethane ( CH₂Cl₂ ), chloroform ( CHCl₃ ), or a combination thereof.
15. A semiconductor processing method according to claim 11, wherein the step of removing a portion of the metal-containing hard mask material is performed without plasma.
16. In claim 11, the substrate comprises an exposed area of a metal material, and the method A semiconductor processing method comprising the step of oxidizing the metal material before flowing the above-mentioned pre-etching precursor into the processing area of the semiconductor processing chamber.
17. As a semiconductor processing method, A step of flowing an etching agent precursor into a processing area of a semiconductor processing chamber—a substrate is accommodated within the processing area, and the substrate defines an exposed area of a metal-containing hard mask material—; A step of contacting the above substrate with the above etching agent precursor; A step of removing at least a portion of the metal-containing hard mask material relative to one or more other materials on the substrate; A step of stopping the delivery of the above-mentioned etching agent precursor; A step of flowing a post-etching precursor into the processing area of the semiconductor processing chamber; A step of contacting the above substrate with the above post-etching precursor; and A semiconductor processing method comprising the step of removing an oxidized portion of the metal-containing hard mask material or a fluorine-containing residue from the substrate.
18. A semiconductor processing method according to claim 17, wherein the etching agent precursor comprises a halogen-containing precursor.
19. A semiconductor processing method according to claim 18, wherein one or more other materials on the substrate comprise a dielectric constant of about 4.0 or less, a metallic material, a silicon-containing material, or a metal-and-oxygen-containing material.
20. A semiconductor processing method according to claim 17, wherein the step of removing a portion of the metal-containing hard mask material is performed at a temperature of about 350°C or higher and a pressure of about 2 Torr or higher.

Description

Systems and methods for selective removal of metal-containing hard masks Cross-reference regarding related applications This application claims the benefit and priority of U.S. Patent Application No. 18/244,583, filed September 11, 2023, titled "SYSTEMS AND METHODS FOR SELECTIVE METAL-CONTAINING HARDMASK REMOVAL," the entirety of which is incorporated herein by reference. Technology field The present invention relates to semiconductor processes and equipment. More specifically, the present invention relates to selectively etching metal-containing hard masks. Integrated circuits can be manufactured by processes that create complexly patterned material layers on substrate surfaces. Creating patterned material on a substrate requires controlled methods to remove the exposed material. Chemical etching is used for various purposes, including transferring a photoresist pattern to underlying layers, thinning layers, or thinning the lateral dimensions of features already present on the surface. Often, it is desirable to have an etching process that etches one material faster than another, for example, to facilitate the pattern transfer process. Such an etching process is referred to as selective for the first material. As a result of the diversity of materials, circuits, and processes, etching processes that are selective for various materials have been developed. Etching processes can be referred to as wet or dry based on the materials used in the process. For example, wet etching can preferentially remove some oxide dielectrics over other dielectrics and materials. However, wet processes may have difficulty penetrating some constrained trenches and, in some cases, can deform the remaining material. Dry etchings, generated from local plasmas formed within the substrate processing area, can penetrate more constrained trenches and may exhibit less deformation of the delicate remaining structures. However, local plasmas can damage the substrate by generating electric arcs when discharged. Therefore, improved systems and methods that can be used to produce high-quality devices and structures are required. These and other needs are addressed by the present technology. Further understanding of the attributes and advantages of the disclosed technology can be realized by referring to the remainder of this specification and the drawings. FIG. 1 illustrates a plan view of one embodiment of an exemplary processing system according to some embodiments of the present technology. FIG. 2a illustrates a schematic cross-sectional view of an exemplary processing chamber according to some embodiments of the present technology. FIG. 2b shows a detailed view of a part of the processing chamber illustrated in FIG. 2a according to some embodiments of the present technology. FIG. 3 illustrates a bottom view of an exemplary shower head according to some embodiments of the present technology. FIG. 4 illustrates exemplary operations in a method according to some embodiments of the present technology. FIGS. 5A and 5B illustrate schematic cross-sectional views of etched materials according to some embodiments of the present technology. Some of the drawings are included as schematics. It should be understood that the drawings are for illustrative purposes only and are not scaled unless specifically stated otherwise. Additionally, as schematics, the drawings are provided for illustrative purposes and may not include all modes or information compared to realistic representations, and may include additional or exaggerated material for illustrative purposes. In the accompanying drawings, similar components and/or features may have the same reference numeral. Additionally, various components of the same type may be distinguished by a character following the reference numeral that distinguishes similar components. Where only the first reference numeral is used in this specification, the description is applicable to any of the similar components having the same first reference numeral, regardless of the character. Specific details for implementing the invention Diluted acids can be used in many different semiconductor processes to clean substrates and remove materials from them. For example, diluted hydrofluoric acid ("dHF") can be an effective etchant for silicon oxide, aluminum oxide, titanium oxide, and other materials, and can be used to remove these materials from substrate surfaces. After the etching or cleaning operation is completed, the acid can be dried from the wafer or substrate surface. Using dHF may be referred to as "wet" etching, and the diluent is often water. Additional etching processes utilizing precursors delivered to the substrate may be used. Additionally, for example, plasma-enhanced processes can selectively etch materials by performing dry etching through the enhancement of precursors via plasma. While wet etchants using aqueous solutions or water-based processes can operate effectively on specific substrate structures, wate