Method and apparatus for minimizing contamination in semiconductor processing chamber

• US 8,287,648 B2
• Filed: 02/09/2009
• Issued: 10/16/2012
• Est. Priority Date: 02/09/2009
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Shero, Eric J, Reed, Joseph C
• Primary Examiner(s): Yuan, Dah-Wei
• Assistant Examiner(s): Thomas, Binu
• Application Number:
  US12/368,081
• Publication Number:
  US 20100202860A1
• Time in Patent Office: 1,345 Days
• Field of Search: 118/719, 118/729, 118/733, 118/663, 414/222.02, 414/805
• US Class Current: 118/719
• CPC Class Codes: H01L 21/68742 characterised by a lifting arrangement, e.g. lift pins
• CPC Class Codes: H01L 21/68764 characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating caroussel

Abstract

A semiconductor processing apparatus includes a reaction chamber, a loading chamber, a movable support, a drive mechanism, and a control system. The reaction chamber includes a baseplate. The baseplate includes an opening. The movable support is configured to hold a workpiece. The drive mechanism is configured to move a workpiece held on the support towards the opening of the baseplate into a processing position. The control system is configured to create a positive pressure gradient between the reaction chamber and the loading chamber while the workpiece support is in motion. Purge gases flow from the reaction chamber into the loading chamber while the workpiece support is in motion. The control system is configured to create a negative pressure gradient between the reaction chamber and the loading chamber while the workpiece is being processed. Purge gases can flow from the loading chamber into the reaction chamber while the workpiece support is in the processing position, unless the reaction chamber is sealed from the loading chamber in the processing position.

Claims

1. A semiconductor processing apparatus comprising:

a cross-flow reaction chamber located above a loading chamber, separated by a baseplate including an opening;

a movable workpiece support configured to hold a semiconductor workpiece;

a drive mechanism configured to move the workpiece support between a loading position and a processing position;

a reaction chamber inlet;

a reaction chamber outlet, wherein the reaction gas inlet is located opposite to the reaction gas outlet, such that reaction gas that flows from the inlet to the outlet travels approximately parallel to a face of the workpiece;

a loading chamber inlet;

a loading chamber outlet; and

a control system configured to control flow through the reaction chamber inlet and outlet and the loading chamber inlet and outlet such that the pressure of the reaction chamber is higher than that of the loading chamber while the workpiece support is moving, and lower than that of the loading chamber while the workpiece support is in the processing position.

2. The apparatus of claim 1, further comprising two or more independently controlled valves configured to allow the regulation of relative pressure and/or the direction of flow between the reaction chamber and the loading chamber.

3. The apparatus of claim 1, wherein the control system is further configured to:

maintain a purge gas flow through the reaction chamber inlet while the workpiece support is moving; and

maintain gas flow through the loading chamber outlet while the workpiece support is moving.

4. The apparatus of claim 1, wherein the control system is further configured to:

maintain a purge gas flow through the loading chamber inlet while the workpiece support is in the processing position; and

maintain gas flow through the reaction chamber outlet while the workpiece support is in the processing position.

5. The apparatus of claim 1, wherein the workpiece support engages the baseplate opening when the workpiece support is in the processing position.

6. The apparatus of claim 5, wherein a gap exists between the baseplate and the workpiece support when the workpiece support engages the baseplate opening in the processing position.

7. The apparatus of claim 5, wherein a seal exists between the baseplate and the workpiece support when the workpiece support engages the baseplate opening in the processing position.

8. The apparatus of claim 6, wherein the gap provides horizontal spacing between parts of the baseplate and the workpiece support.

9. The apparatus of claim 8, wherein the gap further provides vertical spacing between parts of the support and the baseplate.

10. The apparatus of claim 8, wherein the gap comprises an annular horizontal space substantially surrounding the support.

11. The apparatus of claim 6, further comprising one or more pads configured to space the support from the baseplate.

12. The apparatus of claim 6, wherein the gap is configured to create a substantial barrier to fluid communication between the reaction chamber and the loading chamber.

13. The apparatus of claim 7, wherein the seal comprises a metal-on-metal seal between the baseplate and the support.

14. The apparatus of claim 7, wherein the seal comprises a soft seal between the baseplate and the support.

15. The apparatus of claim 3, wherein the control system is further configured to:

maintain gas flow through the reaction chamber outlet while the workpiece support is moving; and

stop gas flow through the loading chamber inlet while the workpiece support is moving.

16. The apparatus of claim 15, wherein the control system is further configured to:

control the amount of gas pumped from the reaction chamber outlet and the loading chamber outlet, such that the amount of gas pumped from the reaction chamber outlet is less than the amount of gas pumped from the loading chamber outlet while the workpiece support is moving.

17. The apparatus of claim 16, further comprising at least one vacuum pump connected to the reaction chamber outlet, wherein the control system is further configured to isolate the reaction chamber from the vacuum pump while the workpiece support is moving.

18. The apparatus of claim 4, wherein the control system is further configured to:

maintain gas flow through the loading chamber outlet while the workpiece support is in the processing position; and

maintain gas flow through the reaction chamber inlet while the workpiece support is in the processing position.

19. The apparatus of claim 18, wherein the control system is further configured to:

control the amount of gas pumped from the reaction chamber outlet and the loading chamber outlet, such that the amount of gas pumped from the loading chamber outlet is less than the amount of gas pumped from the reaction chamber outlet while the workpiece support is in the processing position.