PROCESS CHAMBER SHIELDING SYSTEM AND METHOD

Abstract

A removable coating for protecting process chamber components from excess material resulting from operation of a process chamber. The removable coating including a sheet. A bonding surface of the sheet to be releasably bonded to a process chamber component to be protected. A deposition surface of the coating selected to receive and retain the excess material. In an aspect, the coating may further include a deposition layer bonded to a sheet surface in opposition to the bonding surface. The deposition layer providing the deposition surface. In some aspects the deposition surface may be provided of a different material from the process chamber component. In some aspects, and method and system are provided for protecting process chamber components.

Claims

1. A removable coating for protecting process chamber components from excess material, comprising: a sheet; a bonding surface of the sheet for removable bonding to a process chamber component; and, a deposition surface of the coating adapted to receive and retain the excess material.

2. The removable coating of claim 1, wherein the coating further comprises: a deposition layer bonded to a sheet surface of the sheet in opposition to the bonding surface, the deposition layer providing the deposition surface.

3. The removable coating of claim 1, wherein the deposition surface has been treated to improve capture and retention of the excess material.

4. The removable coating of claim 3, wherein the treatment comprises at least one of: rolling; pressing; and, machining.

5. The removable coating of claim 1, wherein the bonding surface has been treated to provide a bonding texture on the bonding surface for reducing a contact area between the sheet and the process chamber component.

6. The removable coating of claim 3, wherein the treatment comprises impressing a deposition texture into the deposition surface.

7. The removable coating of claim 5, wherein the treatment comprises rolling or pressing the coating to impress the bonding texture into the bonding surface.

8. The removable coating of claim 2 wherein the sheet is 30 m to 10 mm thick, and wherein the deposition layer is 5 nm to 1000 m thick.

9. The removable coating of claim 2, wherein the sheet and the deposition layer comprise a same material.

10. The removable coating of claim 2, wherein the sheet and the deposition layer comprise a different material.

11. The removable coating of claim 2, wherein the deposition layer comprises a metal.

12. The removable coating of claim 1, wherein the sheet comprises a metal sheet.

13. The removable coating of claim 1, wherein the removable bonding comprises spot welding the bonding surface to the process chamber component.

14. A process chamber comprising: walls, base, and cover defining a process chamber cavity; within the process chamber cavity, a pedestal and heater for supporting a substrate to receive a deposition material; and, a removable coating comprising: a sheet; a bonding surface of the sheet releasably bonded to at least one interior surface of the process chamber; and, a deposition surface of the sheet for capturing and retaining the excess material; wherein the bonding surface of the removable coating is releasably bonded to at least one interior surface of the process chamber, the removable coating adapted to receive, capture and retain excess material resulting from operation of the process chamber, and adapted to be removed from the at least one interior surface by breaking the releasable bond between the removable coating and the at least one interior surface while maintaining the bond between the deposition surface and the retained excess material to allow removal of the removable coating and retained excess material from the process chamber.

15. The process chamber of claim 13, wherein the at least one interior surface comprises a shielding component within the process chamber cavity located to shield an interior wall surface of the process chamber from the excess material.

16. The process of claim 13, wherein the sheet comprises a metal sheet.

17. A method for coating a process chamber component comprising: providing a removable coating for protecting the process chamber component from excess material, the removable coating comprising: a sheet; a bonding surface of the sheet for bonding to a process chamber component; and, a deposition surface of the coating adapted to receive and retain the excess material; and, releasably bonding the removable coating by conforming the removable coating to a surface of the process chamber component intended to be protected, and spot welding the removable coating to the process chamber component.

18. (canceled)

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

25. The method of claim 17, wherein the coating further comprises: a deposition layer bonded to a sheet surface of the sheet in opposition to the bonding surface, the deposition layer providing the deposition surface.

26. The method of claim 17, wherein the deposition surface has been treated to improve capture and retention of the excess material.

27. The method of claim 26, wherein the treatment comprises at least one of: rolling; pressing; and, machining.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Embodiments will now be described with reference to the appended drawings in which:

[0031] FIG. 1 is aside cross-section view of an exemplar prior art process chamber.

[0032] FIG. 2 is a side cross-section view of the process chamber of FIG. 1, further including an embodiment of a shield coating.

[0033] FIG. 3 A is a side section view of an embodiment of a coating.

[0034] FIG. 3 B is a side section view of an embodiment of a coating.

[0035] FIG. 4 A is a side section view of an embodiment of a coating.

[0036] FIG. 4 B is a side section view of an embodiment of a coating.

[0037] FIG. 4 C is a side section view of an embodiment of a coating.

[0038] FIG. 4 D is a side section view of an embodiment of a coating.

[0039] FIG. 4 E is a side section view of an embodiment of a coating.

[0040] FIG. 4 F is a side section view of an embodiment of a coating.

DETAILED DESCRIPTION

[0041] Referring to FIG. 1, a cross-section of an exemplar prior art process chamber 10 is illustrated. The process chamber 10 includes a chamber body defined by chamber walls 12, base 13 and cover 14. The chamber body defines a chamber cavity 15 in which the process is contained. The chamber walls 12 and base 13 are commonly constructed in fixed arrangement to one another with the cover 14 being removable. Typically, a sealing ring 16 and sealing gasket 17 are provided to assist with securing the cover 14 in sealing engagement with the walls 12. A magnet 18 is provided above the cover 14 to work in cooperation with a target 19 located on the inside of the cover 14 to generate material to be deposited on a substrate.

[0042] Below the target 19 a pedestal 22 is provided for supporting the wafer 20 to be coated in the process chamber 10. Typically, a heater is located beneath, or within, the pedestal 22 for heating the substrate (wafer 20) and the chamber cavity 15. As illustrated in FIG. 1, shielding components, i.e. process kit components, are provided to shield the walls 12, base 13, and pedestal 22 from deposition of excess material. In the exemplary FIG. 1, the shielding components include an inner shield 24 for shielding the walls 12. The inner shield 24 may further shield the base 13 when working in cooperation with the cover ring 26. A deposition ring 28 further seals edges of the pedestal 20 and the heater 22.

[0043] As will be appreciated, the illustrated shielding components are for illustrative purposes only, and other combinations of shielding components may be employed for a particular process chamber 10. As described above, the purpose of the shielding components is to block deposition of material onto parts of the process chamber 10. Standard semiconductor process chambers employ shielding components of a variety of materials including metals (such as stainless steel and aluminum), high purity ceramic parts, and quartz parts.

[0044] Referring to FIG. 2, the process chamber 10 is illustrated with the addition of a protective removable coating 30. The protective removable coating 30 may be applied to any surface within the process chamber 10 that may be exposed to excess material. In the illustration of FIG. 2, the protective removable coating 30 is applied to shielding components including the inner shield 24, the cover ring 26 and the deposition ring 28, a bonding surface of the removable coating 30 forming a releasable bond with the surface of the shielding components. As will be appreciated, these are the parts of the process chamber 10 that receives the bulk of the excess material, but other parts of the chamber may usefully be covered by the protective removable coating 30.

[0045] The protective removable coating 30 is a removable coating that may be applied over a surface exposed to excess material, such as the shielding components, and presenting a deposition surface to receive the excess material during a process run. In some aspects, the deposition surface may be specifically treated or formed to aid in reception, capture, and retention of the excess material. After completion of the process run, the removable coating 30 may be removed from the deposition surface 31 and, optionally, replaced with a fresh removable coating 30. As will be discussed below, the bond between the removable coating 30and the deposition surface 31 may be relatively weaker than either the bond between the excess material and the removable coating 30 and the bond between the excess material and the deposition surface 31.

[0046] Referring to FIG. 3A, the removable coating 30 may be produced from a suitable sheet 32, such as a metal sheet (for instance: Al, Ti/TiN, Ta/TaN, Cu, Ni, Cr, Zn, SST, Alloys, Alumina (Al2O3), Aluminum nitride (AlN), Yttira (Y203), Alumina-Titania (Al203/TiO2), Yittira-Alumina (Y203/Al03)), Silicon Carbide, Silicon nitride (Si3N4), Quartz (SiO2), and other ceramics, which are standard materials used for constructing process chambers. The sheet 32 may have a varying thickness depending on a shape and configuration of the component to be covered but typically will be between 30 m to 10 mm thick. In a first aspect, the removable coating 30 may comprise the sheet 32, a bonding surface 33 of the sheet 32 to be secured to the component by spot welding, presenting an exposed sheet surface 35 of the sheet 32 as a deposition surface 31 for receiving excess material. Preferably, the spot welding is selected to provide a minimal bond between the bonding surface 33 of the removable coating 30 and the component such that the removable coating 30 stays in place during light handling and operation of the process chamber, but is removable after the operational run life of the coated component. In some aspects, the sheet 32 may comprise a same material as the component. In other aspects, the sheet 32 may comprise a different material from the component.

[0047] In cases where the sheet is non-metallic, e.g. Quartz or ceramic, metal the non-metallic sheet may be formed around metal weld points that are exposed on the bonding surface 33 of the removable coating 30. The metal weld points provide attachment points for spot welding the non-metallic removable coating 30 to the component.

[0048] Referring to FIG. 3B, in a second aspect the removable coating 30 may further comprise a deposition layer 34 bonded to the sheet surface 35. The deposition layer 34 typically comprising a metal deposition onto the sheet surface 35, to improve retention and capture of excess material (for instance: Al, Ti, Ta, Cu, Ni, Cr, Zn, SST, and Alloys). In some aspects the deposition layer 34 may comprises a non-metallic material, to be bonded to the sheet surface 35. In some aspects, the coating may be comprised of a common material for each of the sheet 32 and the deposition layer 34.

[0049] The purpose of the deposition layer 34 is to provide a deposition surface 31 that is more receptive to receiving excess material than the sheet surface 35. The deposition layer 34 is fully bonded to the sheet 32, and of reduced thickness, typically ranging between 5 nm to 1000 m. The deposition layer 34 may be produced, for instance, by anodizing, plasma coating, or spray coating the sheet 32 with the coating material. In some aspects, the deposition layer 34 may comprise a same material as the sheet 32. In some aspects, the deposition layer 34 may comprise a different material as the sheet 32. The deposition layer 34 provides for improved bonding with excess material over the sheet 32 alone, as it has been found that coating the sheet 32 with a deposition layer 34 provides for improved bonding of excess material over the sheet 32 alone.

[0050] Accordingly, a removable coating 30 may be selected for improved bonding characteristics for a given set of process conditions, e.g. excess material, without changing the composition of the underlying component to be protected. Furthermore, a plurality of removable coatings 30, each presenting a different deposition surface 31 may be provided to a manufacturing location. An appropriate removable coating 30 may be applied to shielding components for a specific process chamber run. Provision of removable coatings 30 having different deposition surfaces 31 allows for matching of a particular deposition surface 31 to a specific process chamber operational cycle, while using shielding components of a same composition.

[0051] Referring to FIG. 4 A, in an aspect the removable coating 30 may further comprise a treatment or preparation applied to the deposition surface 31 to impart a deposition texture or desired surface roughness into the deposition surface 31. In the example of FIG. 4A, sheet surface 35 is treated to provide improved bonding for reception and retention of the excess material. The treatment may comprise, for instance, a treatment to provide a deposition texture exhibiting an increase in a roughness of the sheet surface 35 such as by bead blasting, etching, machining, or other means. In other aspects, where the removable coating 30 is ductile, the treatment may comprise a mechanical treatment applied to the sheet 32 to deform the sheet surface 35, for instance by rolling or pressing the sheet 32 with a patterned roller or press having a raised profile, to impress a pattern or irregular surface into the deposition surface 31 as the deposition texture.

[0052] Referring to FIG. 4B, the removable coating 30 comprises the sheet 32 and the deposition layer 34, with a treatment applied to the deposition surface 31 of the deposition layer 34. Depending upon the treatment applied, and the thickness of the deposition layer 34, the treatment may further deform the sheet surface 35, though it is not the deposition surface 31 in this embodiment. For example, where the sheet 32 and the deposition layer 34 are passed through a roller, one of the rollers may include a textured surface to impress a texture onto the deposition surface 31. Where the textured surface is of sufficient profile, both the deposition layer 34 and the sheet surface 35 of the sheet 32 may both be deformed to accommodate the profile.

[0053] Referring to FIGS. 4C and 4 D, in an aspect a similar treatment may be applied to the bonding surface 33 of the sheet 32 to impart a bonding texture in the bonding surface 33. In this case the treatment may be intended to provide reduced contact area between the bonding surface 33 and the shielding component. The reduced contact area may be useful, for instance, to provide a lower bonding force between the removable coating 30 and the component. The reduced contact area may also be useful to assist with temperature maintenance in the process chamber cavity 15 by providing a lower heat transfer rate between the removable coating 30 and the shielding component. In this fashion, the removable coating 30 may provide a measure of insulation to reduce a rate of heat transfer out of the process chamber cavity 15. For some processes the dynamics prefer a relatively slower heat transfer rate out of the process chamber cavity 15. For these processes, a removable coating 30 may be selected for both a material property to reduce heat transfer and/or a reduced coating contact area to reduce the contact between the removable coating 30 and an underlying shielding component. In cases where a relatively higher heat transfer rate is preferred, the bonding surface 33 may be relatively smooth, providing a relatively higher heat transfer rate.

[0054] The treatment may similarly comprise, for instance, a treatment to provide a bonding texture exhibiting an increase in a roughness of the bonding surface 33 such as by bead blasting, etching, or other means. In other aspects, the treatment may comprise a mechanical treatment applied to the sheet 32 to deform the bonding surface 33, for instance by rolling or pressing the sheet 32 with a patterned roller or press having a raised profile, to impress a pattern or irregular surface into the bonding surface 33 as the bonding texture. The bonding texture selected to affect at least one of a bonding between the bonding surface 33 and the shielding component to receive the coating, and a heat transfer rate between the removable coating 30 and the shielding component.

[0055] Referring to FIGS. 4 E and 4F, in an aspect a treatment may be applied to both the deposition surface 31 (and potentially the sheet surface 35), and the bonding surface 33. In this aspect, the treatment may comprise a same treatment applied to both of the opposed surfaces of the removable coating 30. In this aspect, the treating may alternately comprise a different treatment applied to both of the opposed surfaces of the coating.

[0056] According to another aspect of the invention, there is provided a process kit component comprising a base dimensioned to be positioned within a semiconductor process chamber with respect to an intended deposition substrate; and a removable coating 30 for shielding the base, the sheet comprising a metal sheet layer conforming to at least a portion of the base; and a coating layer affixed to and conforming to the metal sheet, the coating having a enhanced bonding strength between metal sheet layer and deposition material there across, wherein the removable coating 30 is selectively removable from the base.

[0057] Because the removable coating 30 is conformable, it can be selectively conformed to various shapes and configurations of an underlying shielding component. The removable coating 30 providing a deposition surface 31 receptive to excess material that can be relied upon to uniformly receive and hold the excess material, and the resultant deposition film build-up without immediate flaking of the film. Furthermore, a coated shielding component may be cleaned by simply removing and discarding the removable coating 30. A fresh coating 30 may be applied, providing a fresh deposition surface 31 for receiving excess material. Furthermore, the make-up of the deposition surface 31 may be tailored to a particular process. For instance, a process chamber running a copper process (i.e. using a copper target) can be shielded by a coating having a copper deposition surface 31. Conveniently, while a soft copper deposition surface 31 may be receptive to capturing copper excess material, the shielding components may be formed from another material, such as steel or titanium for durability. As compared with prior art methods for cleaning a process kit component whose actual surface is deposition surface that receives surface treatment by bead blasting or aluminum arc spraying, simply encapsulating the shielding component or a portion thereof, with a replacement coating 30 takes far less time to complete. As such, the coated shielding component can be quickly cleaned and put back into service. Furthermore, the removable coating 30 may optionally be applied to structural components of the process chamber 10 that may be partially exposed to excess material and require cleaning from time to time.

[0058] As explained above, a removable coating 30 may be provided with a deposition surface 31 matched to an intended excess material. Accordingly, a replacement coating 30 may have a similar roughness as the removable coating 30 it is replacing, or may have a different roughness depending on the type and thickness of an intended excess material. Various replacement removable coatings 30 may be made available in order to provide a selection of roughness levels for use in various stages of deposition where higher or lower stress excess material deposition films are being deposited. In embodiments where the deposition surface 31 comprises a treated surface, the extent of the roughness of a particular removable coating 30 can be tightly controlled, particularly where a mechanical process such as rolling or pressing is employed.

[0059] The removable coating 30 can be applied to any of the exposed surfaces within a process chamber 10.Shielding components comprising ceramic process kit components are typically manufactured with near-mirror smoothness surfaces. In an aspect where the removable coating 30 presents a ceramic deposition surface, the surface may be treated by modifying, for example by machining or bead blasting, at least a portion of the deposition surface to have an enhanced, generally-uniform roughness to improve bonding of excess material to the removable coating 30.

[0060] Although embodiments have been described with reference to the drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the spirit, scope and purpose of the invention as defined by the appended claims.