Catalyst-aided chemical processing method and apparatus

• US 20080073222A1
• Filed: 08/27/2007
• Published: 03/27/2008
• Est. Priority Date: 08/28/2006
• Status: Active Grant

• Current Assignee: Ebara Corporation
• Original Assignee: Ebara Corporation, Osaka University
• Inventors: Murata, Junji, Yagi, Keita, Yamauchi, Kazuto, Hara, Hideyuki, Sano, Yasuhisa
• Granted Patent: US 7,651,625 B2
• Time in Patent Office: Days
• US Class Current: 205/655
• CPC Class Codes: B01J 23/28 Molybdenum
• CPC Class Codes: C23C 18/145 Radiation by charged particles, e.g. electron beams or ion irradiation
• CPC Class Codes: C23C 8/40 using liquids, e.g. salt baths, liquid suspensions
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/26 for etching refractory metals
• CPC Class Codes: C23F 1/30 for etching other metallic material
• CPC Class Codes: C25B 11/00 Electrodes; Manufacture thereof not otherwise provided for
• CPC Class Codes: C25D 21/12 Process control or regulation controlling or regulating in general G05
• CPC Class Codes: C25D 5/06 Brush or pad plating
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/30612 Etching of AIIIBV compounds
• CPC Class Codes: H01L 21/31051 Planarisation of the insulating layers H01L21/31058 takes precedence
• CPC Class Codes: H01L 21/32115 Planarisation
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/32134 by liquid etching only

Abstract

A catalyst-aided chemical processing method can process hard-to-process materials, especially SiC, GaN, etc. whose importance as electronic device materials is increasing these days, with high processing efficiency and high precision even for a space wavelength range of not less than several tens of μm. The catalyst-aided chemical processing method comprises: putting a workpiece in a processing liquid in which halogen-containing molecules are dissolved; and moving the workpiece and a catalyst composed of molybdenum or a molybdenum compound relative to each other while keeping the catalyst in contact with or close proximity to a surface to be processed of the workpiece, thereby processing the surface of the workpiece.

Claims

1. A catalyst-aided chemical processing method comprising:

putting a workpiece in a processing liquid in which halogen-containing molecules are dissolved; and

moving the workpiece and a catalyst composed of molybdenum or a molybdenum compound relative to each other while keeping the catalyst in contact with or close proximity to a surface to be processed of the workpiece, thereby processing the surface of the workpiece.

2. The catalyst-aided chemical processing method according to claim 1, wherein the processing liquid is hydrofluoric acid.

3. The catalyst-aided chemical processing method according to claim 1, wherein the workpiece is composed of a material selected from Si, SiC, GaN, sapphire, ruby and diamond.

4. The catalyst-aided chemical processing method according to claim 1, wherein the surface to be processed of the workpiece is processed and flattened by moving the workpiece, held by a holder, and a flat platen having a surface comprised of the catalyst relative to each other while keeping the surface of the platen in contact with or close proximity to the surface to be processed of the workpiece in the presence of the processing liquid.

5. A catalyst-aided chemical processing method comprising:

putting a workpiece in a processing liquid in which halogen-containing molecules are dissolved; and

bringing a catalyst, composed of platinum, gold, a ceramic solid catalyst, molybdenum or a molybdenum compound, into contact with or close proximity to a surface to be processed of the workpiece, thereby processing the workpiece;

wherein at least one of a voltage application process for applying a voltage between the surface to be processed of the workpiece and the catalyst during the processing, a light irradiation process for irradiating the surface to be processed of the workpiece with light during or before the processing, a workpiece temperature control process for controlling the temperature of the workpiece during the processing, a processing liquid temperature control process for controlling the temperature of the processing liquid, and a catalyst temperature control process for controlling the temperature of the catalyst is carried out, either singly or in a combination of two or more, in the processing of the workpiece.

6. A catalyst-aided chemical processing apparatus comprising:

a platen having a surface comprised of a catalyst composed of molybdenum or a molybdenum compound;

a holder for holding a workpiece and bringing a surface to be processed of the workpiece into contact with the platen;

a processing liquid supply section for supplying a processing liquid, in which halogen-containing molecules are dissolved, between the platen and the workpiece held by the holder and kept in contact with the platen; and

a drive section for moving the platen and the workpiece, held by the holder and kept in contact with the platen, relative to each other.

7. A catalyst-aided chemical processing apparatus comprising:

a platen having a surface comprised of a catalyst composed of platinum, gold, a ceramic solid catalyst, molybdenum or a molybdenum compound;

a holder for holding a workpiece and bringing a surface to be processed of the workpiece into contact with the platen;

a processing liquid supply section for supplying a processing liquid, in which halogen-containing molecule are dissolved, between the platen and the workpiece held by the holder and kept in contact with the platen;

a drive section for moving the platen and the workpiece, held by the holder and kept in contact with the platen, relative to each other; and

at least one of a power source for applying a voltage between the surface to be processed of the workpiece and the catalyst, a light source for irradiating the surface to be processed of the workpiece with light, a workpiece temperature control mechanism for controlling the temperature of the workpiece during processing, a processing liquid temperature control mechanism for controlling the temperature of the processing liquid, and a catalyst temperature control mechanism for controlling the temperature of the catalyst.

8. A catalyst-aided chemical processing method comprising:

putting a workpiece in an oxidizing processing liquid;

bringing a solid catalyst, having an acidic or basic nature, into contact with or close proximity to a surface to be processed of the workpiece; and

dissolving surface atoms of the surface to be processed, which is in contact with or close proximity to the solid catalyst, in the oxidizing processing liquid, thereby processing the surface of the workpiece.

9. The catalyst-aided chemical processing method according to claim 8, wherein the oxidizing processing liquid is ozone water or a hydrogen peroxide solution.

10. The catalyst-aided chemical processing method according to claim 8, wherein the surface to be processed of the workpiece is irradiated with light during or before the processing of the workpiece.

11. The catalyst-aided chemical processing method according to claim 8, wherein at least one of the temperature of the workpiece, the temperature of the oxidizing processing liquid and the temperature of the solid catalyst is controlled during the processing of the workpiece.

12. The catalyst-aided chemical processing method according to claim 8, wherein a voltage is applied between the surface to be processed of the workpiece and the solid catalyst during the processing of the workpiece.

13. The catalyst-aided chemical processing method according to claim 8, wherein the solid catalyst has or forms a processing reference plane, and the configuration or pattern of the processing reference plane is transferred to the surface of the workpiece.

14. The catalyst-aided chemical processing method according to claim 8, wherein the solid catalyst is a non-woven fabric, a resin or a metal, having an ion exchange function.

15. The catalyst-aided chemical processing method according to claim 8, wherein the solid catalyst is a metal oxide having an acidic or basic nature.

16. The catalyst-aided chemical processing method according to claim 8, wherein the solid catalyst in a powdery form is dispersed in the oxidizing processing liquid, and the powder is supplied to the surface to be processed of the workpiece by a flow of the oxidizing processing liquid.

17. A catalyst-aided chemical processing method comprising:

irradiating with light a surface to be processed of a workpiece put in a processing liquid;

bringing a solid catalyst, having an acidic or basic nature, into contact with or close proximity to the surface to be processed of the workpiece; and

dissolving surface atoms of the surface to be processed, which is in contact with or close proximity to the solid catalyst, in the processing liquid, thereby processing the surface of the workpiece.

18. The catalyst-aided chemical processing method according to claim 17, wherein at least one of the temperature of the workpiece, the temperature of the processing liquid and the temperature of the solid catalyst is controlled during the processing of the workpiece.

19. The catalyst-aided chemical processing method according to claim 17, wherein a voltage is applied between the surface to be processed of the workpiece and the solid catalyst during the processing of the workpiece.

20. The catalyst-aided chemical processing method according to claim 17, wherein the solid catalyst has or forms a processing reference plane, and the configuration or pattern of the processing reference plane is transferred to the surface to be processed of the workpiece.

21. The catalyst-aided chemical processing method according to claim 17, wherein the solid catalyst is a non-woven fabric, a resin or a metal, having an ion exchange function.

22. The catalyst-aided chemical processing method according to claim 17, wherein the solid catalyst is a metal oxide having an acidic or basic nature.

23. The catalyst-aided chemical processing method according to claim 17, wherein the solid catalyst in a powdery form is dispersed in the oxidizing processing liquid, and the powder is supplied to the surface to be processed of the workpiece by a flow of the oxidizing processing liquid.

24. A catalyst-aided chemical processing apparatus comprising:

a platen having a surface comprised of a fixed solid catalyst having an acidic or basic nature;

a holder for holding a workpiece and bringing a surface to be processed of the workpiece into contact with or close proximity to the surface of the platen;

an oxidizing processing liquid supply section for supplying an oxidizing processing liquid between the platen and the workpiece held by the holder and kept in contact with or close proximity to the surface the platen; and

a drive section for moving the platen and the workpiece, held by the holder and kept in contact with or close proximity to the platen, relative to each other.

25. The catalyst-aided chemical processing apparatus according to claim 24 further comprising a light source for irradiating the surface to be processed of the workpiece with light.

26. The catalyst-aided chemical processing apparatus according to claim 24 further comprising a power source for applying a voltage between the surface to be processed of the workpiece and the solid catalyst.

27. The catalyst-aided chemical processing apparatus according to claim 24 further comprising a temperature control mechanism for controlling at least one of the temperature of the workpiece, the temperature of the processing liquid and the temperature of the solid catalyst during processing of the workpiece.

28. A catalyst-aided chemical processing apparatus comprising:

a platen having a surface comprised of a fixed solid catalyst having an acidic or basic nature;

a holder for holding a workpiece and bringing a surface to be processed of the workpiece into contact with or close proximity to the surface of the platen;

a processing liquid supply section for supplying a processing liquid between the platen and the workpiece held by the holder and kept in contact with or close proximity to the surface the platen;

a light source for irradiating the surface to be processed of the workpiece with light; and

a drive section for moving the platen and the workpiece, held by the holder and kept in contact with or close proximity to the platen, relative to each other.

29. The catalyst-aided chemical processing apparatus according to claim 28 further comprising a power source for applying a voltage between the surface to be processed of the workpiece and the solid catalyst.

30. The catalyst-aided chemical processing apparatus according to claim 28 further comprising a temperature control mechanism for controlling at least one of the temperature of the workpiece, the temperature of the processing liquid and the temperature of the solid catalyst during processing of the workpiece.

31. A catalyst-aided chemical processing method comprising:

putting a workpiece in a processing liquid containing an oxidizing agent;

bringing a solid catalyst, capable of decomposing the oxidizing agent, into contact with or close proximity to a surface to be processed of the workpiece; and

removing a compound from the workpiece or dissolving the compound in the processing liquid, said compound being formed by a chemical reaction between an active species having a strong oxidizing power, generated on the solid catalyst, and a surface atom of the workpiece, thereby processing the workpiece;

wherein at least one of a light irradiation means for irradiating the surface to be processed of the workpiece with light during the processing, a voltage application means for applying a voltage between the surface to be processed of the workpiece and the solid catalyst during the processing, a catalyst temperature control means for controlling the temperature of the catalyst, a workpiece temperature control means for controlling the temperature of the workpiece, and a processing liquid temperature control means for controlling the temperature of the processing liquid is applied, either singly or in a combination of two or more, to the processing of the surface.

32. The catalyst-aided chemical processing method according to claim 31, wherein a stabilizer for stabilizing the oxidizing agent is added to the processing liquid to control the decomposition rate of the oxidizing agent.

33. The catalyst-aided chemical processing method according to claim 31, wherein the oxidizing agent is H₂O₂ or O₃.

34. The catalyst-aided chemical processing method according to claim 31, wherein the solid catalyst is a transition metal selected from Fe, Ni, Co, Cu, Cr and Ti, a noble metal selected from platinum and gold, a metal oxide ceramic, a glass, or a basic solid catalyst, or a combination thereof.

35. The catalyst-aided chemical processing method according to claim 31, wherein the workpiece is composed of crystalline SiC, sintered SiC, GaN, sapphire, ruby or diamond.

36. The catalyst-aided chemical processing method according to claim 31, wherein the oxidizing agent is H₂O₂, the solid catalyst is Fe and the workpiece is composed of SiC, GaN or diamond, and the processing is carried out by utilizing the Fenton reaction.

37. The catalyst-aided chemical processing method according to claim 32, wherein the oxidizing agent is H₂O₂ and the stabilizer is sodium silicate.

38. The catalyst-aided chemical processing method according to claim 31, wherein the solid catalyst in a powdery form is dispersed in the processing liquid containing an oxidizing agent, and the powdery solid catalyst is supplied to the surface to be processed of the workpiece by a flow of the processing liquid.

39. A catalyst-aided chemical processing apparatus comprising:

a flat rotary platen having a surface comprised of a solid catalyst capable of decomposing an oxidizing agent; and

a holder having a rotating shaft eccentric to the rotating shaft of the platen;

wherein a surface to be processed of a workpiece is processed and flattened by supplying a processing liquid containing the oxidizing agent between the surface of the solid catalyst and the surface to be processed of the workpiece, and rotating the workpiece, held by the holder, and the rotary platen while pressing the workpiece against the platen at a predetermined pressure; and

wherein at least one of a light irradiation means for irradiating the surface to be processed of the workpiece with light during the processing, a voltage application means for applying a voltage between the surface to be processed of the workpiece and the solid catalyst during the processing, a solid catalyst temperature control means for controlling the temperature of the solid catalyst, a workpiece temperature control means for controlling the temperature of the workpiece, and a processing liquid temperature control means for controlling the temperature of the processing liquid is applied, either singly or in a combination of two or more, to the processing of the surface.

40. A catalyst-aided chemical processing apparatus comprising:

a processing liquid containing an oxidizing agent and dispersing a solid catalyst, capable of decomposing the oxidizing agent, in a powdery form therein; and

a processing liquid supply section for supplying the powdery solid catalyst to a surface to be processed of a workpiece by a flow of the processing liquid;

wherein at least one of a light irradiation section for irradiating the surface to be processed of the workpiece with light, a voltage application section for applying a voltage between the surface to be processed of the workpiece and the solid catalyst, a solid catalyst temperature control section for controlling the temperature of the solid catalyst, a workpiece temperature control section for controlling the temperature of the workpiece, and a processing liquid temperature control section for controlling the temperature of the processing liquid is applied, either singly or in a combination of two or more, to processing of the surface.