PVD target having self-retained low friction pads
Embodiments of target assemblies for use in substrate processing chambers are provided herein. In some embodiments, a target assembly includes a plate comprising a first side including a central portion and a support portion, a target disposed on the central portion, a plurality of recesses formed in the support portion; and a plurality of self-retained low-friction pads partially disposed in the plurality of recesses, wherein each of the plurality of low-friction pads includes a solid body portion, and a self-retaining stem that extends outward from a bottom of the solid body portion, wherein the self-retaining stem includes a first stem portion disposed in the first through-hole portion, and a second stem portion disposed within the second through-hole portion.
1. A target assembly for a substrate processing chamber, comprising:
a plate comprising a first side including a central portion and a support portion, wherein the central portion is configured to support target source material; a plurality of recesses formed in the support portion, wherein each of the plurality of recesses includes a first through-hole portion having a first diameter, and a second through-hole portion having a second diameter that is larger than the first diameter of the first through-hole; and
a plurality of low-friction pads partially disposed in the plurality of recesses, wherein each of the plurality of low-friction pads includes:
a solid body portion; and
a self-retaining stem that extends outward from a bottom of the solid body portion, wherein the self-retaining stem includes a first stem portion disposed in the first through-hole portion, and a second stem portion disposed within the second through-hole portion.
2. The target assembly of claim 1 , wherein the plurality of recesses are circumferentially spaced around the plate.
3. The target assembly of claim 1 , wherein the plurality of recesses are similarly sized.
4. The target assembly of claim 1 , wherein the second stem portion includes a claw portion that is wider than the first diameter of the first stem portion along a first direction.
5. The target assembly of claim 4 , wherein the claw portion is flat on two sides in a second direction perpendicular to the first direction, such that a width of the flat sides is narrower than the first diameter of the of the first stem portion.
6. The target assembly of claim 4 , wherein the self-retaining stem includes at least two slots configured to allow the self-retaining stem to be compressed to allow the second stem portion to fit though the second through-hole portion.
7. The target assembly of claim 6 , wherein the claw portion comes in contact with a retaining surface withing the second through-hole portion configured to retain the pad within the recess.
8. The target assembly of claim 1 , wherein each of the plurality of low-friction pads includes a bearing surface.
9. The target assembly of claim 8 , wherein a surface area of the bearing surface of each of the plurality of low-friction pads is about 0.20 square inches to about 0.35 square inches.
10. The target assembly of claim 1 , wherein each of the plurality of low-friction pads are chamfered at the corners of the solid body portion.
11. The target assembly of claim 1 , wherein each of the plurality of low-friction pads comprise a seating surface and a bearing surface, wherein, when the seating surface is supported on a bottom surface of a recess, the bearing surface is spaced above the first side of the plate.
12. The target assembly of claim 11 , wherein the bearing surface is spaced about 0.05 mm to about 1 mm above the first side.
13. The target assembly of claim 1 , wherein the plate includes a groove separating the support portion into an atmospheric side radially outward from the groove and a vacuum side radially inward from the groove.
14. The target assembly of claim 13 , wherein the plurality of recesses are formed in the atmospheric side.
15. The target assembly of claim 1 , wherein the plurality of low-friction pads are replaceable low-friction pads.
16. The target assembly of claim 1 , wherein the plurality of low-friction pads are formed from one or more of ultra-high-molecular-weight polyethylene or polyether ether ketone.
17. A substrate processing apparatus, comprising:
a chamber body;
a lid disposed atop the chamber body;
a target assembly coupled to the lid, the target assembly including
a backing plate having a first side and an opposing second side, wherein the first side of the backing plate is configured to support target source material;
a plurality of recesses formed in the backing plate, wherein each of the plurality of recesses includes a first through-hole portion having a first diameter, and a second through-hole portion having a second diameter; and
a plurality of self-retained low-friction pads partially disposed in the plurality of recesses, wherein each of the plurality of self-retained low-friction pads includes:
a solid body portion; and
a self-retaining stem that extends outward from a bottom of the solid body portion, wherein the self-retaining stem includes a first stem portion disposed in the first through-hole portion, and a second stem portion disposed within the second through-hole portion;
a support member coupled to the lid proximate an outer end of the support member and extending radially inward; and
a seal ring disposed between the backing plate and the support member wherein the seal ring is supported by the support member along a bottom surface of the seal ring, and wherein a top surface of the seal ring contacts the target assembly along the bearing surfaces of the plurality of self-retained low-friction pads.