SYSTEM AND METHOD FOR SUBSTRATE TRANSPORT

• US 20090324369A1
• Filed: 06/30/2009
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Intevac
• Original Assignee: Intevac
• Inventors: SCOLLAY, Stuart, Bluck, Terry, Chen, Xiang
• Granted Patent: US 8,992,153 B2
• Time in Patent Office: Days
• US Class Current: 414/222.01
• CPC Class Codes: H01L 21/67173 in-line arrangement
• CPC Class Codes: H01L 21/67313 Horizontal boat type carrier whereby the substrates are vertically supported, e.g. comprising rod-shaped elements
• CPC Class Codes: H01L 21/67775 Docking arrangements
• CPC Class Codes: H01L 21/67781 Batch transfer of wafers
• CPC Class Codes: Y10S 414/14 Wafer cassette transporting

Abstract

Introduction of substrates into vacuum environment is accomplish by gradually reducing the number of substrates being transferred simultaneously as the clean and evacuated environment is progressed. Cassettes are maintained in clean atmospheric environment and do not enter the vacuum environment. Several vacuum locks are linearly staggered so as to introduce progressively higher level of vacuum environment. The number of substrates transported through this arrangement is a portion of the number of substrates present in each cassette. The staggered vacuum locks lead to a series of processing chambers, wherein a yet smaller number of substrates, e.g., one or two, are transported.

Claims

1. A substrate processing system comprising:

a front end module having tracks for transporting cassettes, each cassette holding a preset number of substrates therein;

a staggered vacuum lock module coupled to the front end module and having tracks for transporting transport carriers, each transport carrier capable of supporting a second preset number of substrates, the second preset number being smaller than the first preset number;

a plurality of processing chambers coupled to the vacuum lock module and having tracks for transporting processing carriers, each processing carrier capable of supporting a third preset number of substrates, the third preset number being smaller than the second preset number.

2. The substrate processing system of claim 1, wherein the staggered vacuum lock module comprises a load module and an unload module.

3. The substrate processing system of claim 2, wherein the front end module further comprises a loading robot arm, an unloading robot arm, and a turntable positioned between the loading and unloading robot arms.

4. The substrate processing system of claim 3, further comprising a buffer station positioned between the staggered vacuum lock module and the plurality of processing chambers.

5. The substrate processing system of claim 4, wherein buffer station is maintained in vacuum and comprises a second turntable for transferring transport carriers from the load module to the unload module.

6. The substrate processing system of claim 5, wherein the buffer station further comprises an elevator for removing substrates from the transport carriers.

7. The substrate processing system of claim 6, wherein the transport carrier comprises a base and a removable substrate supporting part, and wherein the elevator is structured to engage and lift the substrate supporting part from the base.

8. The substrate processing system of claim 1, wherein each of the processing carriers is structured to support two substrates held back-to-back, such that only one surface of each substrate is exposed for processing.

9. The substrate processing system of claim 1, wherein each of the processing carriers is structured to support two substrates held in tandem, such that both surfaces of each substrate are exposed for processing.

10. The substrate processing system of claim 1, wherein the front end module is maintained at an atmospheric environment.

11. The substrate processing system of claim 1, wherein the first present number is selected from 15 to 25;

the second preset number is selected from 3 to 6; and

the third preset number is selected from 1 to 4.

12. A method for processing substrates, comprising:

loading a preset number of substrate onto a cassette;

transporting the cassette in an atmospheric environment;

repeatedly removing groups of substrates from the cassette and transferring each group from an atmospheric environment into a vacuum environment, each of the groups having a smaller number of substrates than the preset number; and

,

repeatedly loading a subset of substrates from the group of substrates onto a processing carrier and transporting the carrier through a plurality of processing chambers, wherein the each subset comprising a number of substrates smaller than the number of substrates in the group of substrates.

13. The method of claim 12, wherein transferring each group from an atmospheric environment into a vacuum environment comprises loading each group onto a transport carrier and transporting the transport carrier through a vacuum chambers, each maintaining a higher level of vacuum.

14. The method of claim 13, further comprising, prior to repeatedly loading a subset of substrates, removing the group of substrates from the transport carrier and placing the group of substrates onto a buffer station.

15. The method of claim 14, further comprising after removing the group of substrates, removing the transport carrier from the vacuum environment into an atmospheric environment.

16. A substrate processing system comprising:

an array of a plurality of processing chambers, each chamber having tracks for transporting processing carriers;

a buffer station coupled to the array and maintained under vacuum environment;

a loading vacuum lock module coupled to the buffer station and having tracks for transporting transport carriers from an atmospheric environment into the buffer station;

an unloading vacuum lock module coupled to the buffer station and having tracks for transporting transport carriers from the buffer station and out to an atmospheric environment;

a front end module having tracks for transporting cassettes in an atmospheric environment, wherein each cassette holding a preset number of substrates therein.

17. The substrate processing system of claim 16, further comprising a turntable positioned to receive transport carriers from the unloading vacuum lock module and for transporting transport carriers into the loading vacuum lock module.

18. The substrate processing system of claim 16, wherein the transport carriers are structured to support a number of substrates that is smaller than the number of substrates in the cassettes and wherein the processing carriers are structured to support a number of substrates that is smaller than the number of substrates in the transport carriers.

19. The substrate processing system of claim 16, further comprising a loading arm structured to remove substrates from the cassettes and place them onto the transport carriers;

and an unloading arm structured to remove substrates from the transport carriers and place them into the cassettes.

20. The substrate processing system of claim 16, further comprising a transport mechanism structured to relay transport carriers between the loading vacuum lock module to the unloading vacuum lock module.