Keyed wafer carrier

Patent metadata

Field	Value
Publication number	US-9816184-B2
Application number	US-201213424821-A
Country	US
Kind code	B2
Filing date	Mar 20, 2012
Priority date	Mar 20, 2012
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

A structure for a chemical vapor deposition reactor desirably includes a reaction chamber having an interior, a spindle mounted in the reaction chamber, and a wafer carrier releasably mounted onto the spindle for rotation therewith. The spindle desirably has a shaft extending along a vertical rotational axis and a key projecting outwardly from the shaft. The wafer carrier preferably has a body defining oppositely-facing top and bottom surfaces and at least one wafer-holding feature configured so that a wafer can be held therein with a surface of the wafer exposed at the top surface of the body. The wafer carrier desirably further has a recess extending into the body from the bottom surface of the body and a keyway projecting outwardly from a periphery of the recess along a first transverse axis. The shaft preferably is engaged in the recess and the key preferably is engaged into the keyway.

First claim

The invention claimed is:

1. A wafer carrier comprising:
a body defining oppositely-facing top and bottom surfaces, a peripheral surface extending between the top and bottom surfaces, and a vertical rotational axis substantially perpendicular to the top and bottom surfaces, the body having reference indicia defined in at least one of the top surface, the bottom surface, or the peripheral surface, the reference indicia being visible to an imaging device;
a plurality of pockets defined in the top surface of the body, each pocket configured so that a wafer is holdable therein with a surface of the wafer exposed at the top surface of the body, each said pocket having a center;
a recess extending into the body from the bottom surface of the body, the recess defining a periphery; and
a keyway projecting outwardly from the periphery of the recess away from the rotational axis along a first transverse axis, the reference indicia being disposed at a predetermined location relative to the keyway in a circumferential direction around the vertical rotational axis,
wherein at least some of the pockets are disposed adjacent the rotational axis and arranged in a circular pattern distributed around the rotational axis with spaces between centers of adjacent pockets in the pattern, and wherein the keyway is aligned with one said space such that the first transverse axis bisects the one said space.

2. The wafer carrier as claimed in claim 1 , wherein the at least some of the pockets that are arranged in the circular pattern are distributed symmetrically around the vertical rotational axis.

3. The wafer carrier as claimed in claim 1 , wherein a plane parallel to the bottom surface of the wafer carrier and containing the first transverse axis extends through the reference indicia.

4. The wafer carrier as claimed in claim 1 , wherein the wafer carrier is substantially disc-shaped.

5. A structure for a chemical vapor deposition reactor, the structure comprising the wafer carrier as claimed in claim 1 , the structure further comprising:
a reaction chamber having an interior; and
a spindle mounted in the reaction chamber, the spindle having a shaft extending along the vertical rotational axis and a key projecting outwardly from the shaft along the first transverse axis, wherein the wafer carrier is releasably mounted onto the spindle for rotation therewith about the vertical rotational axis, the shaft being engaged in the recess and the key being engaged into the keyway.

6. The structure as claimed in claim 5 , wherein the key has a tip portion engaged into the keyway, the tip portion having an upper surface confronting and spaced apart from a downward-facing surface of the body exposed within the keyway so that the key does not constrain the body against downward movement relative to the shaft.

7. The structure as claimed in claim 5 , wherein the shaft has a top end and a tapered contact surface having progressively increasing diameter in the downward direction away from the top end.

8. The structure as claimed in claim 7 , wherein the shaft has a main portion below the tapered contact surface and the key is engaged with the main portion of the shaft.

9. The structure as claimed in claim 7 , wherein the body has a downward-facing recess end surface and a tapered contact surface within the recess extending downwardly from the recess end surface, the tapered contact surface of the body being at least partially in contact with the tapered contact surface of the shaft, and wherein the end surface is spaced apart from the top end of the spindle.

10. The structure as claimed in claim 9 , wherein a centroid of the surface contact between the tapered contact surfaces of the body and the shaft is located above the center of gravity of the body.

11. The structure as claimed in claim 5 , wherein the spindle has an aperture extending through the shaft along the first transverse axis and the key includes a shank engaged in the aperture.

12. The structure as claimed in claim 11 , wherein the spindle further defines a recess extending from the top end of the shaft along the vertical rotational axis, wherein the spindle further includes a fork removably engaged in the recess, the fork having a pair of tines, the shank of the key being engaged between the tines of the fork.

13. The structure as claimed in claim 12 , wherein the shank of the key has a central portion located between the two tines of the fork and end portions adjacent the central portion, the central portion having a width that is less than a separation distance between the tines of the fork, each end portion having a width that is greater than the separation distance, such that the key is interlocked between the two tines and retained by the fork against movement relative to the shaft along the first transverse axis.

14. The structure as claimed in claim 13 , wherein the central portion of the key includes oppositely-facing substantially planar side surfaces, each side surface disposed adjacent a surface of one of the tines, such that the key is rotationally fixed by the fork against rotation about the first transverse axis.

15. The structure as claimed in claim 12 , wherein the key and the fork each consist essentially of a first material, and wherein the shaft consists essentially of a second material different than the first material.

16. The structure as claimed in claim 12 , wherein the fork includes a threaded aperture and the threaded aperture is exposed at the top end of the shaft.

17. The structure as claimed in claim 11 , wherein the key has a tip portion disposed outside of the shaft, the tip portion having a height in a longitudinal direction parallel to the vertical rotational axis that is greater than a diameter of the aperture.

18. The structure as claimed in claim 17 , wherein the tip portion of the key has a rounded upper surface that faces toward the top end of the shaft.

19. The structure as claimed in claim 5 , wherein the at least some of the pockets that are arranged in the circular pattern are distributed symmetrically around the vertical rotational axis.

20. The structure as claimed in claim 5 , wherein a plane parallel to the bottom surface of the wafer carrier and containing the first transverse axis extends through the reference indicia.

21. The structure as claimed in claim 5 , further comprising an encoder connected to the spindle and arranged to provide a signal representing the rotational orientation of the spindle, an automated vision system adapted to detect the rotational location of the reference indicia, and a robotic control system arranged to rotate at least one of the wafer carrier and the spindle to align the rotational locations of the key and the keyway to one another.

22. The structure as claimed in claim 5 , wherein the wafer carrier is substantially disc-shaped.

23. The wafer carrier as claimed in claim 1 , wherein the body has a downward-facing recess end surface and a tapered contact surface within the recess extending downwardly from the recess end surface.

24. The structure as claimed in claim 5 , further comprising a control system configured to determine the rotational location of the keyway relative to the rotational axis from the observation of the rotational orientation of the reference indicia relative to the rotational axis.

25. The wafer carrier as claimed in claim 1 , wherein the body of the wafer carrier defines a downward-facing surface ex

Assignees

• Krishnan Sandeep
• Moy Keng
• Gurary Alexander I
• King Matthew
• Boguslavskiy Vadim
• Krommenhoek Steven
• Veeco Instr Inc

Inventors

• Krishnan Sandeep
• Moy Keng
• Gurary Alexander I
• King Matthew
• Boguslavskiy Vadim
• Krommenhoek Steven

Classifications

• H10P72/7626

  characterised by the construction of the shaft · CPC title

• H10P72/7621 Primary

  characterised by supporting two or more semiconductor substrates · CPC title

• H10P72/7618

  characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating carrousel · CPC title

• H10P72/0462

  characterised by the construction of the processing chambers, e.g. modular processing chambers · CPC title

• H01L21/6719

  Electricity · mapped topic