Thermal process station with heated lid

• US 6,884,066 B2
• Filed: 08/01/2003
• Issued: 04/26/2005
• Est. Priority Date: 09/10/2002
• Status: Active Grant

• Current Assignee: TEL Manufacturing and Engineering of America, Inc.
• Original Assignee: FSI International, Inc. (Tokyo Electron Limited)
• Inventors: Zhu, Xiaoguang, Sims, Richard E., Nguyen, Vuong P.
• Primary Examiner(s): WILSON, GREGORY A
• Application Number:
  US10/633,124
• Publication Number:
  US 20040048220A1
• Time in Patent Office: 634 Days
• Field of Search: 432/253, 432/258, 432/247, 432/237, 432/250, 392/416, 392/418, 118/725, 118/728, 219/444.1, 219/390, 219/405, 219/443.1, 219/457
• US Class Current: 432/250
• CPC Class Codes: F27B 17/0025 Especially adapted for treating semiconductor wafers
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67126 Apparatus for sealing, encapsulating, glassing, decapsulating or the like processes H01L23/02, H01L23/28

Abstract

Methods and apparatuses to improve the temperature uniformity of a workpiece being processed on a heated platen of a thermal processing station. A heated platen is enclosed in a housing incorporating an additional heat source that uniformly outputs thermal energy into the process chamber in which the heated platen is positioned. In preferred embodiments, this heat source is positioned in the lid of the housing. It is additionally preferred that the heated lid includes features that provide a gas flow path to introduce to and/or purge gas from the process chamber. In terms of photoresist performance, the improved thermal uniformity provided by using such an additional heat source in the housing, e.g., in the lid, offers improved line width control and line uniformity across a wafer.

Claims

1. A thermal process station for thermally processing a workpiece, the station comprising:

an enclosed process chamber in which a heated platen is positioned, the heated platen having a face over which the workpiece is positioned during a thermal treatment; and

a lid assembly comprising;

a first stage comprising an additional heat source, the additional heat source being in thermally conductive contact with the process chamber; and

a second stage comprising at least a portion of an inlet plenum system through which a gas is supplied to the process chamber and at least a portion of an exhaust plenum system through which a gas is exhausted from the process chamber, wherein at least one of the inlet and exhaust plenum systems comprises a plurality of radial flow channels.

2. The thermal process station of claim 1, wherein the inlet plenum system comprises a plurality of radial flow channels.

3. The thermal process station of claim 1, wherein the additional heat source comprises a planar heating device, and wherein the first stage further comprises a headspace above a top surface of the planar heating device.

4. The thermal process station of claim 3, wherein the planar heating device is adjacent a floor of the first stage.

5. The thermal process station of claim 1, wherein the first stage comprises a lid chamber in which the additional heat source is positioned.

6. The thermal process station of claim 1, wherein the additional heat source is spaced apart from the enclosed process chamber.

7. The thermal process station of claim 1, wherein the additional heat source is thermally coupled to the enclosed process chamber by a plurality of radial walls.

8. The thermal process station of claim 1, wherein a heating face of the additional heat source is opposed to the heated platen face.

9. The thermal process station of claim 1, further comprising:

a first gap between a major surface of the heated platen and a first major surface of the workpiece such that a heat flux from the heated platen to the first major surface of the workpiece flows across the first gap; and

a second gap between the additional heat source and a second major surface of the workpiece such that a heat flux from the additional heat source to the second major surface of the workpiece flows across the second gap.

10. A thermal process station for thermally processing a workpiece, the station comprising:

a housing comprising a heated lid assembly and a bottom housing assembly that closably engages the heated lid assembly;

a process chamber inside the housing defined at least in part by the heated lid assembly and the bottom housing assembly;

a lid chamber inside the heated lid assembly;

a heat source positioned inside the lid chamber in a manner such that the heat source is in thermal contact with the process chamber; and

a heated platen inside the process chamber on which the workpiece is supported during a thermal treatment.

11. The thermal process station of claim 10, wherein the heated lid assembly further comprises:

a first stage comprising the lid chamber; and

a second stage positioned between the first stage and the process chamber, the second stage comprising at least a portion of an inlet plenum system and at least a portion of an exhaust plenum system.

12. The thermal process station of claim 10, wherein the heated lid assembly further comprises:

an upper stage comprising the lid chamber, wherein the heat source positioned in the lid chamber is thermally coupled to a floor of the lid chamber; and

a lower stage comprising one or more walls that help to thermally couple the upper stage to the process chamber.

13. The thermal process station of claim 10, wherein the heat source is spaced apart from the process chamber.

14. The thermal process station of claim 13, wherein the heat source is thermally coupled to the process chamber by a plurality of radial walls.

15. The thermal process station of claim 10, further comprising:

a first gap between a major surface of the heated platen and a first major surface of the workpiece such that a heat flux from the heated platen to the first major surface of the workpiece flows across the first gap; and

a second gap between the heat source and a second major surface of the workpiece such that a heat flux from the heat source to the second major surface of the workpiece flows across the second gap.

16. A thermal process station for thermally processing a workpiece, the station comprising:

a heated lid assembly closeably engaging a bottom housing assembly;

a processing chamber defined at least in part by the bottom housing assembly;

at least a portion of an inlet plenum system in the heated lid assembly comprising a gas flow path in fluid communication with the processing chamber; and

at least a portion of an exhaust plenum system in the heated lid assembly comprising a gas flow path in fluid communication with the process chamber, wherein at least one of the inlet and exhaust plenum systems comprises a plurality of radial flow channels.

17. The thermal process station of claim 16, wherein at least a portion of the radial flow channels differ dimensionally from each other.

18. The thermal process station of claim 16, wherein the heated lid assembly further comprises:

a lid chamber comprising;

a heat source positioned in the lid chamber; and

a headspace above a top surface of the heat source.

19. The thermal process station of claim 18, further comprising:

a heated platen inside the processing chamber on which the workpiece is supported during a thermal treatment;

a first gap between a major surface of the heated platen and a first major surface of the workpiece such that a heat flux from the heated platen to the first major surface of the workpiece is across the first gap; and

a second gap between the heat source and a second major surface of the workpiece such that a heat flux from the heat source to the second major surface of the workpiece flows across the second gap.

20. A method of improving the thermal uniformity of a workpiece during a thermal treatment, comprising the steps of:

providing a first heat source having a first heating face;

providing a second heat source having a second heating face, wherein the first and second heating faces are opposed to each other such that at least part of the space between the first and second heat source define a process chamber;

providing an inlet plenum system comprising a gas flow path in fluid communication with the process chamber and an exhaust plenum system comprising a gas flow path in fluid communication with the process chamber, wherein at least one of the inlet and exhaust plenum systems comprises a plurality of radial flow channels; and

positioning the workpiece between the first and second, opposed heating faces during at least a portion of the thermal treatment.

21. A thermal process station for thermally processing a workpiece, the station comprising:

an enclosed process chamber in which a heated platen is positioned, the heated platen having a face over which the workpiece is positioned during a thermal treatment; and

a lid assembly comprising;

a first stage comprising a lid chamber in which an additional heat source is positioned, the additional heat source being in thermally conductive contact with the process chamber; and

a second stage comprising at least a portion of an inlet plenum system through which a gas is supplied to the process chamber and at least a portion of an exhaust plenum system through which a gas is exhausted from the process chamber, wherein the second stage is positioned between the first stage and the enclosed process chamber, wherein at least one of the inlet and exhaust plenum systems comprises a plurality of radial flow channels, and wherein the radial flow channels differ dimensionally from each other.