Method and apparatus for controlling the spatial temperature distribution across the surface of a workpiece support

• US 7,274,004 B2
• Filed: 11/30/2004
• Issued: 09/25/2007
• Est. Priority Date: 04/30/2001
• Status: Expired due to Term

• Current Assignee: Lam Research Corporation, Yokowo Company Limited
• Original Assignee: Lam Research Corporation
• Inventors: Steger, Robert, Benjamin, Neil
• Primary Examiner(s): PAIK, SANG YEOP
• Application Number:
  US11/001,218
• Publication Number:
  US 20050173403A1
• Time in Patent Office: 1,029 Days
• Field of Search: 219/443.1, 219/444.1, 219/390, 118/724, 118/725, 427/240, 156/345.51, 156/345.52, 156/345.53
• US Class Current: 219/444.1
• CPC Class Codes: H01J 2237/2001 Maintaining constant desired temperature
• CPC Class Codes: H01J 37/20 Means for supporting or positioning the object or the material; Means for adjusting diaphragms or lenses associated with the support
• CPC Class Codes: H01L 21/67103 mainly by conduction
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

A chuck for a plasma processor comprises a temperature-controlled base, a thermal insulator, a flat support, and a heater. The temperature-controlled base has a temperature below the desired temperature of a workpiece. The thermal insulator is disposed over the temperature-controlled base. The flat-support holds a workpiece and is disposed over the thermal insulator. A heater is embedded within the flat support and/or disposed on an underside of the flat support. The heater includes a plurality of heating elements that heat a plurality of corresponding heating zones. The power supplied and/or temperature of each heating element is controlled independently.

Claims

1. A chuck assembly for a plasma processor, the chuck assembly comprising:

a support element for supporting a workpiece; and

a single-piece base element disposed below the support element and thermally coupled thereto, the base element having a continuous layer of thermal insulator disposed upon a surface thereof, the base element thermally separated by at least one lateral thermal break into at least two temperature controlled portions, wherein one portion is disk-shaped, and a peripheral portion extends beyond the support element, each portion independently thermally controllable by circulating a temperature controlled fluid through a fluid loop associated with each portion.

2. The chuck assembly of claim 1, further comprising a thermally conductive medium disposed over the support element.

3. The chuck assembly of claim 1, wherein the wafer support element further comprises a first temperature sensor disposed above a first portion of the base element and a second temperature sensor disposed above a second portion of the base element.

4. The chuck assembly of claim 3, further comprising a controller responsive to said first and second temperature sensors and configured to control temperature in the first and second portions of the base element.

5. The chuck assembly of claim 1 wherein the lateral thermal break comprises a thermally insulating material.

6. The chuck assembly of claim 1 wherein the independently thermally controllable portions control the temperature of the support element.

7. The chuck assembly of claim 1 wherein the insulator has a thermal conductivity range of 0.05 W/mK to 0.20 W/mK.

8. A method comprising:

determining a fluid temperature corresponding to each of two or more portions of a single-piece base element of a chuck assembly, the base element having a continuous layer of thermal insulator disposed upon a surface thereof, the base element thermally separated by at least one lateral thermal break into at least two temperature controlled portions, wherein one portion is disk-shaped, and a peripheral portion extends beyond the support element, each portion independently thermally controllable by circulating a temperature controlled fluid through a fluid loop associated with each portion;

circulating a fluid of the determined fluid temperature through a fluid loop associated with each of the corresponding portions to control the temperature of a workpiece disposed upon a support element of the chuck assembly, the support element disposed above the base element and thermally coupled thereto.