METHOD AND APPARATUS FOR PRODUCING A GAS CURTAIN OF PURGE GAS IN A SLIT VALVE TUNNEL

Abstract

Contamination of semiconductor wafers during coating and other operations is mitigated by passing the wafer through a tunnel with a slit providing a gas curtain which impinges upon the wafer as the wafer is transported from one station to the next station in the processing apparatus.

Claims

1.-7. (canceled)

8. An apparatus for treating a semiconductor wafer comprising: a tunnel having a first portion and a second portion opposite the first portion, the tunnel having an opening defining a transport path for transporting a semiconductor wafer from a first side to a second side of the tunnel or vice versa, the opening being between the first portion and a second portion and in communication with a channel via a slit, the channel extending from a first end to a second end of the first portion and the slit being laterally defined by a wall; and a cover configured to be removably fastened to the tunnel along the channel; wherein, during operation, a gas is directed through the channel forming a gas curtain from the first portion towards the second portion such that it impinges a surface of the semiconductor wafer that is transported along the transport path from the first side through the opening to the second side.

9. The apparatus of claim 8, wherein the channel is configured to receive the gas from the first and second ends.

10. The apparatus of claim 9, wherein the tunnel defines a first hole configured to feed the gas to the first end of the channel and a second hole configured to feed the gas to the second end of the channel.

11. The apparatus of claim 10, wherein the first and second holes are defined in the first side.

12. The apparatus of claim 8, wherein the tunnel includes a recess on an exterior of the first portion for receiving the cover.

13. The apparatus of claim 12, wherein the channel is disposed in the recess.

14. The apparatus of claim 8, wherein the wall is perpendicular to the transport path.

15. The apparatus of claim 8, wherein at least a portion of the wall is beveled.

16. The apparatus of claim 8, wherein the channel extends transversely to the transport path.

17. The apparatus of claim 8, further comprising a first module adjacent the first side of the tunnel, and a second module adjacent the second side of the tunnel such that when the semiconductor wafer is transported through the opening it travels from the first module to the second module.

18. The apparatus of claim 17, wherein the first module is a process chamber, or a lock camber and the second module is transfer chamber.

19. The apparatus of claim 18, wherein the wall is beveled opposite the process chamber or lock chamber such that the gas curtain directs particles away from the process chamber or lock chamber.

20. The apparatus of claim 8, further comprising a door to close the opening.

21. The apparatus of claim 8, wherein the first portion is a top portion, and the second portion is a bottom portion such that when gas is directed through the channel to form the gas curtain the gas curtain travels from the top portion towards the bottom portion.

22. A method for protecting a semiconductor wafer from contamination comprising: directing a purge gas through the channel of the apparatus of claim 8 to form the gas curtain; and transporting the semiconductor wafer along transport path such that the gas curtain impinges the surface of the semiconductor wafer.

23. The method of claim 22, wherein the cover is removed before or after the gas curtain is formed and the tunnel is cleaned along the channel.

24. The method of claim 22, wherein the gas curtain impinges the surface of the semiconductor wafer at an angle of 90°.

25. The method of claim 22, wherein the gas curtain impinges the surface of the semiconductor wafer at an angle not equal to 90°.

26. The method of claim 25, wherein the gas curtain is directed counter to a direction the semiconductor wafer is being transported along.

27. The method of claim 22, wherein the semiconductor wafer is transported from a transfer chamber adjacent the tunnel to a process chamber or a lock chamber adjacent the tunnel.

28. The method of claim 27, wherein the gas curtain is directed in a direction away from the process chamber or the lock chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 shows an embodiment of a slit valve tunnel in a perspective view.

[0029] FIG. 2 shows the slit valve tunnel according to FIG. 1 with the cover removed.

[0030] FIG. 3 is a view of the rear side of the slit valve tunnel according to FIG. 1 with an active gas curtain.

[0031] FIG. 4 is a cross-sectional schematic diagram of the slit valve tunnel according to FIG. 1 from the side.

[0032] FIG. 5 is a diagram of a cross-section of the slit valve tunnel according to FIG. 1 in a first embodiment.

[0033] FIG. 6 is a diagram of a cross-section of the slit valve tunnel according to FIG. 1 in a second embodiment.

LIST OF REFERENCE NUMERALS USED

[0034] 1 slit valve tunnel [0035] 2 top portion [0036] 3 bottom portion [0037] 4 through-opening [0038] 5 rear side [0039] 6 cover [0040] 7 holes [0041] 8 recess [0042] 9 channel [0043] 10 ends [0044] 11 gas curtain [0045] 12 transport path [0046] 13 wall [0047] A first module [0048] B second module

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] FIG. 1 shows a preferred embodiment of the slit valve tunnel 1 in a perspective view. The slit valve tunnel 1 comprises a top portion 2, a bottom portion 3 and a through-opening 4 between the top portion and the bottom portion. In this view, the rear side 5 of the slit valve tunnel 1 can be seen. A removable cover 6 is fastened to the upper side of the top portion by means of screws. In the region of two rounded upper corners of the rear side 5 of the slit valve tunnel 1 there are provided two holes 7 through which purge gas is directed to the two ends of a channel which is covered by the cover 6. Arrows symbolize the direction of flow of the purge gas.

[0050] FIG. 2 shows the slit valve tunnel 1 according to FIG. 1 with the cover 6 removed. On the upper side of the top portion 2 there is provided a recess 8 into which the cover 6 fits positively. A channel 9 having two ends 10 is incorporated in the recess, which channel extends almost over the width of the through-opening 4 and is open at the bottom to a slit (not shown).

[0051] FIG. 3 is a view of the rear side 3 of the slit valve tunnel according to FIG. 1 with an active gas curtain 11 of purge gas.

[0052] FIG. 4 is a schematic diagram of the slit valve tunnel according to FIG. 1 from the side, wherein the rear side 5 of the slit valve tunnel 1 is adjacent to a module A of the apparatus for treating a semiconductor wafer and the front side of the slit valve tunnel 1 is adjacent to a module B of the apparatus. The arrow symbolizes the direction of movement of a door (not shown) for closing the through-opening 4. The module A is, for example, a process chamber or a lock chamber and module B is a transfer chamber.

[0053] FIG. 5 is a diagram of a section of the slit valve tunnel in a preferred embodiment, in which the slit in the bottom of the channel is delimited by a vertical wall 13. The gas curtain impinges on the wafer at an angle of 90°.

[0054] FIG. 6 is a diagram of a section of the slit valve tunnel in another preferred embodiment, in which the slit in the bottom of the channel is delimited by a wall 13 which is beveled. Owing to the wall, the gas curtain is diverted into the direction in which the arrow points.

[0055] The above description of exemplary embodiments is to be understood as being by way of example. The disclosure made thereby on the one hand makes it possible for the skilled person to understand the present invention and the advantages associated therewith and on the other hand also includes variations and modifications of the described structures and method that are obvious in the understanding of the skilled person. All such variations and modifications as well as equivalents are therefore to be covered by the scope of protection of the claims.