Cylindrical magnetron target and apparatus for affixing the target to a rotatable spindle assembly

• US 6,375,815 B1
• Filed: 02/17/2001
• Issued: 04/23/2002
• Est. Priority Date: 02/17/2001
• Status: Expired due to Fees

• Current Assignee: David Mark Lynn
• Original Assignee: David Mark Lynn
• Inventors: Lynn, David Mark, Clarkson, Melvin Marion
• Primary Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US09/788,060
• Time in Patent Office: 430 Days
• Field of Search: 204/298.21, 204/298.22
• US Class Current: 204/298.22
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: H01J 37/3435 Target holders (includes backing plates and endblocks)

Abstract

An improved interconnection system for attaching an improved cylindrical magnetron target to a rotatable flanged spindle incorporates an annular extension on the target, which fits over the edge of the spindle flange, facilitates centering the target on the spindle, and helps shield target sealing surfaces. The annular extension terminates in an inwardly-angled circumferential step. The target-spindle interconnection system includes a split clamping collar and generally annular retainer ring that slidable over the spindle shaft and rotatable against the spindle flange, the retainer ring having external circumferential threads that are angled away from the flange. The split clamping collar has, at one end, an inwardly-angled lip that engages the overhanging step and, at the other end, inwardly-angled, internal, circumferential threads that engage the threads of the retainer ring to draw the target and spindle together as a unified assembly as the retainer ring is rotated.

Claims

1. An apparatus for affixing a cylindrical magnetron target to a rotatable support spindle, said apparatus comprising:

a support spindle structure including a target attachment flange, said target attachment flange having a rear face and front face which incorporates a circumferential groove into which an O-ring seal is inserted;

a cylindrical target structure having a circumferential shoulder at a spindle attachment end thereof, said shoulder terminating in an inwardly-angled, overhanging circumferential step that faces away from said spindle attachment end;

a clamping collar comprised of arcuate segments, which are collectively sized to generally and coaxially surround said cylindrical target structure, said clamping collar incorporating, both an inwardly-angled clamping ledge that engages the overhanging circumferential step of the cylindrical target structure and at least one internal, inwardly-angled, spiral, circumferential thread spaced apart from said inwardly-angled clamping ledge; and

a retainer ring sized so as to be slidable over the support spindle structure, and rotatable against the rear face of the target attachment flange, said retainer ring incorporating external, spiral, circumferential threads that are angled away from the spindle flange, the external, spiral, circumferential threads of said retainer ring engaging the at least one internal, inwardly-angled, spiral, circumferential thread of said clamping collar to draw the inwardly-angled clamping ledge and engaged cylindrical target structure toward the target attachment flange as the retainer ring is rotated in a thread engaging direction.

2. The apparatus of claim 1, wherein the external, spiral, circumferential threads of said retainer ring and the at least one internal, inwardly-angled, spiral, circumferential thread of said clamping collar are generally of parallelogram cross section.

3. The apparatus of claim 1, wherein said clamping collar is comprised of a pair of generally 180-degree arcuate segments.

4. The apparatus of claim 1, wherein the external, spiral, circumferential threads of said retainer ring and the at least one internal, inwardly-angled, spiral, circumferential thread of said clamping collar are of a left-handed spiral configuration.

5. The apparatus of claim 1, wherein said cylindrical target structure further comprises a circumferential lip at a spindle attachment end thereof, said lip fitting over a front edge of said target attachment flange.

6. The apparatus of claim 1, wherein said retainer ring is equipped with a plurality of spanner wrench engagement recesses about its periphery.

7. The apparatus of claim 1, wherein said cylindrical target structure further comprises an inner circumferential sealing surface which mates with said O-ring seal.

8. The apparatus of claim 7, wherein a circumferential lip is proximate said inner circumferential sealing surface in order to afford the latter protection against mechanical damage.