Staged-vacuum wafer processing system and method

• US 5,186,718 A
• Filed: 04/15/1991
• Issued: 02/16/1993
• Est. Priority Date: 05/19/1989
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Maydan, Dan, Somekh, Sasson, Tepman, Avi, Grunes, Howard
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Graybill, David E.
• Application Number:
  US07/685,976
• Time in Patent Office: 673 Days
• Field of Search: 148/DIG. 6, 148/21, 148/25, 148/22, 148/169, 118/715, 118/719, 118/50.1, 118/620, 29/25.01, 29/25.02, 29/25.03, 437/81, 437/105-107, 437/926, 437/925, 204/192, 204/12, 204/298
• US Class Current: 29/25.01
• CPC Class Codes: H01L 21/67167 surrounding a central transfer chamber
• CPC Class Codes: H01L 21/67184 characterized by the presence of more than one transfer chamber
• CPC Class Codes: H01L 21/67742 Mechanical parts of transfer devices robots in general in B25J
• CPC Class Codes: Y10S 148/006 Apparatus
• CPC Class Codes: Y10S 148/169 Vacuum deposition, e.g. including molecular beam epitaxy

Abstract

A processing system for workpieces such as semiconductor wafers is disclosed which incorporates multiple, isolated vacuum stages between the cassette load lock station and the main vacuum processing chambers. A vacuum gradient is applied between the cassette load lock and the main processing chambers to facilitate the use of a very high degree of vacuum in the processing chambers without lengthy pump down times. Separate robot chambers are associated with the vacuum processing chambers and the load lock(s). In addition, separate transport paths are provided between the two robot chambers to facilitate loading and unloading of workpieces. Pre-treatment and post-treatment chambers may be incorporated in the two transport paths.

Claims

1. A staged vacuum-isolation processing system comprising:

a multiplicity of isolatable communicating regions including at least a vacuum load lock chamber;

a vacuum workpiece-processing chamber and an intermediate workpiece transport region; and

vacuum means communicating with the isolatable regions for establishing a vacuum gradient of decreasing pressure across the system from load lock chamber to workpiece-processing chamber.

23. The system of claim 1, wherein the intermediate workpiece transport region comprises:

first and second vacuum, workpiece transfer chambers connecting with one another along a first path between the first workpiece transfer chamber and the second workpiece transfer chamber via a first intermediate vacuum processing chamber and along a second path between the first workpiece transfer chamber and the second workpiece transfer chamber via a second vacuum intermediate processing chamber;

the load lock chamber communicating with the first workpiece transfer chamber; and

the workpiece-processing chamber communicating with the second workpiece transfer chamber.

2. A workpiece transport system comprising first and second vacuum chambers and a pair of vacuum passageways interconnecting the first and second vacuum chambers and providing selectable isolation of, and separate workpiece transport paths between, the first and second vacuum chambers.

3. A workpiece transport system comprising first and second vacuum chambers, including respective first and second robot means therein for loading and unloading workpieces;

and first and second vacuum passageways interconnecting the first and second robot-containing vacuum chambers for providing separate transport paths between said vacuum chambers.

4. The workpiece transport system of claim 3, further comprising valve means for isolating the first and second robot-containing vacuum chambers and the first and second vacuum passageways, one from the other.

5. The workpiece transport system of claim 4, further comprising vacuum load lock means including at least a first vacuum load lock chamber in communication with the first robot-containing vacuum chamber for supplying wafers to and receiving wagers from said first vacuum chamber;

and at least one vacuum processing chamber connected to the second robot-containing vacuum chamber.

6. The workpiece transport system of claim 3 or 5, at least one of the first and second vacuum passageway further including a treatment chamber therein for treating workpieces prior to transfer from one of the first and second robot-containing vacuum chambers to the other.

7. The workpiece transport system of claim 6, further comprising at least a first and a second workpiece process chamber in communication, respectively, with the first and second robot-containing vacuum chambers;

and valve means for isolating the first and second vacuum process chambers from their associated robot-containing chambers, whereby the atmosphere in the first vacuum processing chamber is isolated from the atmosphere in the second vacuum processing chamber via the intervening chambers and passageways.

8. A multiple chamber staged-vacuum semiconductor wafer processing system, comprising:

a plurality of semiconductor wafer processing chambers;

a wafer load/unload chamber for supplying and receiving wafers;

a plurality of chambers interposed between and providing a pair of transfer paths between the load/unload chamber and the processing chambers;

valve means situated along said transfer paths and interposed between adjacent chambers and selectively sealing said adjacent chambers to selectively isolate said adjacent chambers one from the other; and

vacuum means communicating with the isolatable vacuum chambers for establishing a vacuum gradient of decreasing pressure across the system from load lock chamber to semiconductor wafer-processing chamber.

9. The staged vacuum semiconductor wafer processing system of claim 8, wherein the semiconductor wafer processing chambers are selected from deposition and etching chambers.

10. The staged vacuum semiconductor wafer processing system of claim 9, the semiconductor wafer processing chambers including at least a physical vapor deposition chamber.

11. A multiple chamber staged vacuum semiconductor wafer processing system, comprising:

at least a plurality of semiconductor wafer processing chambers;

a wafer load/unload station supplying wafers for processing in the processing chambers and receiving wafers from the processing chambers; and

a chamber housing including first and second wafer transfer chambers communicating with one another along a first path from the first wafer transfer chamber to the second wafer transfer chamber via a first intermediate processing chamber and along a second path from the second wafer transfer chamber via a second intermediate processing chamber to the first wafer transfer chamber, the load/unload station being mounted to and communicating with the first wafer transfer chamber and the semiconductor wafer processing chambers being mounted to and communicating with the second wafer transfer chamber.

12. The multiple chamber staged vacuum semiconductor wafer processing system of claim 11, wherein the first intermediate chamber is adapted for semiconductor wafer cleaning.

13. The multiple chamber staged vacuum semiconductor wafer processing system of claim 11, wherein the first intermediate chamber is a wafer cool down chamber.

14. The multiple chamber staged vacuum semiconductor wafer processing system of claim 11, wherein the intermediate chambers are adapted for treating a wafer prior of subsequent to processing in the processing chambers.

15. The multiple chamber stage vacuum semiconductor wafer processing system of claim 11, the first and second wafer transfer chambers each having a robot mounted therein for respectively (1) reciprocally transferring wafers between the loading and unloading station and the intermediate chambers and (2) for reciprocally transferring wafers between individual ones of the processing chambers, and between the processing chambers and the intermediate chambers.

16. The multiple chamber staged vacuum semiconductor wafer processing system of claim 15, wherein the robot in the second or transfer station comprises a slide mounted within the chamber for horizontal reciprocal rotation;

a wafer holding arm mounted on the slide for reciprocal sliding movement;

a pair of co-axial shafts, a first one of the shafts connected to the slide for imparting reciprocal θ

rotation to the slide and the second shaft being connected via link means to the wafer arm for translating reciprocal rotational movement of said shaft into reversible R translation of said wafer arm.

17. A staged vacuum semiconductor wafer processing system comprising:

(1) a multiplicity of vacuum processing chambers;

(2) wafer queuing load lock chamber means for imputing wafers to and retrieving wafers from the system;

(3) a multiplicity of vacuum processing and transfer stations interposed between and providing a serial transfer path between the load lock chamber means and the processing chambers;

(4) valve means situated along said transfer path and interposed between adjacent chambers and selectively sealing said chambers to isolate said adjacent chambers one from the other and thereby form a serial array of isolated vacuum stations of said chambers; and

(5) vacuum means for establishing a selected base vacuum level in the separate isolated vacuum stages and a vacuum gradient of decreasing pressure across the system from load lock chamber means to the vacuum processing chambers, thereby reducing the time required to pump down each chamber to its selected base vacuum level.

18. A staged-vacuum semiconductor wafer processing system, comprising:

(1) a chamber housing including a first relatively small robot chamber and a second relatively large robot chamber, the robot chambers communicating with one another via a pair of intermediate chambers, along a first path from the first robot via a first intermediate chamber to the second robot chamber and along a second path from the second robot chamber via a second intermediate chamber to the first robot chamber;

(2) load lock means mounted on the first robot chamber;

(3) at least a plurality of vacuum processing chambers mounted on the second robot chamber;

(4) the first robot chamber having a robot mounted therein for reciprocally transferring wafers between the load lock means and said intermediate chambers;

(5) the second robot chamber having a robot mounted therein for reciprocally transferring wafers between the processing chambers and between the processing chambers and the intermediate chambers;

(6) access ports between and for providing communication between (a) the individual process chambers and the second robot chamber, (b) the second robot chamber and the two intermediate chambers, (c) the two intermediate chambers and the first robot chamber, and (d) the first robot chamber and the load lock means;

(7) valve means for selectively opening and closing said access ports;

(8) vacuum means for selectively providing a staged vacuum in the system with a relatively low degree of vacuum in the load lock means and a relatively high degree of vacuum in the processing chambers; and

(9) computer means for controlling processing within the vacuum processing chambers and selectively transferring wafers from said load lock means via the first path to selected vacuum processing chambers and from selected vacuum processing chambers via the second path to the load lock means.

19. The staged-vacuum semiconductor wafer processing system of claim 18, wherein the valve means selectively isolated the vacuum chamber or stages, and wherein the vacuum means establishes a selected base vacuum level in each chamber and a vacuum gradient across the system from chamber-to-chamber, thereby reducing the time required to pump down each chamber to its selected base level.

20. A method of transporting workpieces in vacuo, comprising transferring selected workpieces from a first vacuum chamber to a second vacuum chamber along a first passageway interconnecting the chambers and returning selected wafers from the second to the first chamber via a second passageway interconnecting the chambers.

21. The transporting method of claim 20, wherein the first and second vacuum chambers are robotic workpiece transfer chambers each of which is in communication with one or more vacuum processing or treatment chambers.

22. A method of transporting a workpiece through a vacuum system comprising loading a workpiece at a vacuum load lock chamber means;

sequentially transferring the workpiece within the system through isolated regions of increasing vacuum levels to a vacuum processing chamber for selected processing of the workpiece; and

upon completion of the selected processing, returning the workpiece to the load lock chamber means.