CN-115552572-B - System and method for removing tungsten-containing films

Abstract

An exemplary etching method may include flowing a halogen-containing precursor into a remote plasma region of a semiconductor processing chamber while igniting a plasma to generate plasma effluents. The method may include contacting a substrate contained in a processing region with a plasma effluent. The substrate may define exposed regions of tungsten oxide. Contact may produce tungsten oxyfluoride material. The method may include flowing an etchant precursor into a processing region. The method may include contacting a tungsten oxyfluoride material with an etchant precursor. The method may include removing tungsten oxyfluoride material.

Inventors

• CUI ZHENJIANG
• R.P. Reddy
• WANG ANCHUAN

Assignees

• 应用材料公司

Dates

Publication Date

20260505

Application Date

20211117

Priority Date

20201120

Claims (20)

1. 1. An etching method, comprising: Flowing a halogen-containing precursor into a remote plasma region of a semiconductor processing chamber while igniting a plasma to produce a plasma effluent; contacting a substrate contained in a processing region with the plasma effluent, wherein the substrate defines an exposed region of tungsten oxide, and wherein the contacting produces tungsten oxyfluoride material; Increasing a pressure in the semiconductor processing chamber; Flowing an etchant precursor into the processing region; contacting the tungsten oxyfluoride material with the etchant precursor, and And removing the tungsten oxyfluoride material.
2. 2. The etching method of claim 1, wherein the halogen-containing precursor comprises fluorine, and wherein the etchant precursor comprises a chlorine-containing precursor.
3. 3. The etching method of claim 2, wherein the halogen-containing precursor comprises nitrogen trifluoride, the method further comprising: hydrogen is flowed using the halogen-containing precursor.
4. 4. The etching method of claim 3, wherein the hydrogen flow rate is at least twice the halogen-containing precursor flow rate.
5. 5. The etching method of claim 1, wherein the semiconductor processing chamber is maintained plasma-free during the flow of the etchant precursor.
6. 6. The etching method of claim 1, wherein the etching method is performed at a temperature greater than or equal to 150 ℃.
7. 7. The etching method of claim 1, wherein a pressure in the semiconductor processing chamber is maintained at less than or equal to 15 torr while flowing the halogen-containing precursor.
8. 8. The etching method of claim 7, wherein a pressure in the semiconductor processing chamber is maintained at greater than or equal to 15 torr while flowing the etchant precursor.
9. 9. The etching method of claim 1, wherein the substrate further comprises an exposed region of silicon oxide.
10. 10. The etching method of claim 9, wherein a trench is formed through the silicon oxide to define an exposed region of the tungsten oxide.
11. 11. An etching method, comprising: Forming a plasma of the first halogen-containing precursor to generate a plasma effluent in a remote plasma region of the semiconductor processing chamber; flowing the plasma effluent into a processing region of the semiconductor processing chamber at a first pressure; Contacting a substrate contained in the processing region with the plasma effluent, wherein the substrate comprises an exposed region of tungsten oxide covering a tungsten region at a bottom of a trench defined in the substrate, and wherein the plasma effluent halogenations the tungsten oxide; Flowing a second halogen-containing precursor into the processing region of the semiconductor processing chamber at a second pressure, wherein the second pressure is greater than the first pressure, and The halogenated tungsten oxide is removed.
12. 12. The etching method of claim 11, wherein the first halogen-containing precursor comprises fluorine, and wherein the second halogen-containing precursor comprises boron trichloride.
13. 13. The etching method of claim 11, further comprising stopping plasma formation prior to flowing the second halogen-containing precursor.
14. 14. The etching method of claim 11, wherein the first halogen-containing precursor comprises nitrogen trifluoride, the method further comprising: Hydrogen is flowed using the first halogen-containing precursor.
15. 15. The etching method of claim 14, wherein the hydrogen flow rate is at least twice the flow rate of the first halogen-containing precursor.
16. 16. The etching method of claim 11, wherein a pressure in the semiconductor processing chamber is maintained at less than or equal to 15 torr while flowing the first halogen-containing precursor.
17. 17. The etching method of claim 16, wherein a pressure in the semiconductor processing chamber is maintained at greater than or equal to 15 torr while flowing the second halogen-containing precursor.
18. 18. An etching method, comprising: forming a plasma of the fluorine-containing precursor to generate a plasma effluent in a remote plasma region of the semiconductor processing chamber; flowing the plasma effluent into a processing region of the semiconductor processing chamber; contacting a substrate contained in the processing region with the plasma effluent, wherein the substrate comprises an exposed region of tungsten oxide covering a tungsten region, and wherein the plasma effluent fluorinates the tungsten oxide; Increasing a pressure in the semiconductor processing chamber; Flowing a chlorine-containing precursor into the processing region of the semiconductor processing chamber; contacting the substrate with the chlorine-containing precursor, and And removing the tungsten oxide.
19. 19. The etching method of claim 18, further comprising: Flowing hydrogen with the fluorine-containing precursor, wherein the flow rate of hydrogen is at least twice the flow rate of the fluorine-containing precursor.
20. 20. The etching method of claim 18, wherein a pressure in the semiconductor processing chamber is maintained at less than or equal to 10 torr while flowing the fluorine-containing precursor, and wherein a pressure in the semiconductor processing chamber is maintained at greater than or equal to 20 torr while flowing the chlorine-containing precursor.

Description

System and method for removing tungsten-containing films Cross Reference to Related Applications The present application claims the benefit and priority of U.S. non-provisional application No. 17/100,141, entitled "system and method for removing tungsten-containing films" filed on 11/20/2020, the contents of which are incorporated herein by reference in their entirety for all purposes. Technical Field The present technology relates to semiconductor processing and apparatus. More particularly, the present technology relates to selectively etching tungsten-containing structures. Background Integrated circuits are made possible by the process of creating a complex patterned layer of material on the substrate surface. Creating patterned material on a substrate requires a controlled method to remove the exposed material. Chemical etching is used for various purposes including transferring patterns in the photoresist into 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 material, facilitating, for example, a pattern transfer process. This etching process is referred to as selective to the first material. Due to the diversity of materials, circuits, and processes, etching processes have been developed that are selective to a wide variety of materials. The etching process may be referred to as wet or dry, depending on the materials used in the process. For example, wet etching may preferentially remove some oxide dielectrics over other dielectrics and materials. However, wet processing can have difficulty penetrating some limited trenches and can also sometimes deform the remaining material. The dry etch generated in the localized plasma formed within the substrate processing region may penetrate the more confined trenches and exhibit less deformation of the fine residual structure. However, by generating an arc upon discharge, the localized plasma may damage the substrate. Accordingly, there is a need for improved systems and methods that can be used to produce high quality devices and structures. The present technology addresses these and other needs. Disclosure of Invention An exemplary etching method may include flowing a halogen-containing precursor into a remote plasma region of a semiconductor processing chamber while igniting a plasma to generate plasma effluents. The method may include contacting a substrate contained in a processing region with a plasma effluent. The substrate may define exposed regions of tungsten oxide. Contact may produce tungsten oxyfluoride material. The method may include flowing an etchant precursor into a processing region. The method may include contacting a tungsten oxyfluoride material with an etchant precursor. The method may include removing tungsten oxyfluoride material. In some embodiments, the halogen-containing precursor may be or include fluorine. The etchant precursor may be or include a chlorine-containing precursor. The halogen-containing precursor may be or include nitrogen trifluoride. The method may include flowing hydrogen using a halogen-containing precursor. The flow rate of hydrogen may be at least twice the flow rate of the halogen-containing precursor. The semiconductor processing chamber may be maintained plasma-free during the flow of the etchant precursor. The etching process may be performed at a temperature greater than or about 150 ℃. The pressure in the semiconductor processing chamber may be maintained below or about 15 torr while the halogen-containing precursor is flowed. The pressure in the semiconductor processing chamber may be maintained above or about 15 torr while the etchant precursor is flowed. The substrate may include exposed regions of silicon oxide. Trenches may be formed through the silicon oxide to define exposed regions of tungsten oxide. Some embodiments of the present technology may cover etching methods. The method may include forming a plasma of a first halogen-containing precursor to generate a plasma effluent in a remote plasma region of a semiconductor processing chamber. The method may include flowing a plasma effluent into a processing region of a semiconductor processing chamber. The method may include contacting a substrate contained in a processing region with a plasma effluent. The substrate may include an exposed region of tungsten oxide that covers a tungsten region at the bottom of a trench defined in the substrate. The plasma effluent may halogenate the tungsten oxide. The method may include flowing a second halogen-containing precursor into a processing region of a semiconductor processing chamber. The method may include removing the halogenated tungsten oxide. In some embodiments, the first halogen-containing precursor may be or include fluorine. The second halogen-containing precursor may be or include boron trichloride. The method may include stopping plas