High temperature chuck for plasma processing systems

Patent metadata

Field	Value
Publication number	US-9728437-B2
Application number	US-201514612472-A
Country	US
Kind code	B2
Filing date	Feb 3, 2015
Priority date	Feb 3, 2015
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A wafer chuck assembly includes a puck, a shaft and a base. An insulating material defines a top surface of the puck, a heater element is embedded within the insulating material, and a conductive plate lies beneath the insulating material. The shaft includes a housing coupled with the plate, and electrical connectors for the heater elements and the electrodes. A conductive base housing couples with the shaft housing, and the connectors pass through a terminal block within the base housing. A method of plasma processing includes loading a workpiece onto a chuck having an insulating top surface, providing a DC voltage differential across two electrodes within the top surface, heating the chuck by passing current through heater elements, providing process gases in a chamber surrounding the chuck, and providing an RF voltage between a conductive plate beneath the chuck, and one or more walls of the chamber.

First claim

We claim:

1. A wafer chuck assembly, comprising:
a puck comprising:
an electrically insulating material defining a top surface of the puck;
a heater element embedded within the electrically insulating material;
a plurality of electrodes embedded within the electrically insulating material and disposed between the heater element and the top surface; and
an electrically conductive plate disposed proximate to the electrically insulating material;
a shaft comprising:
an electrically conductive shaft housing that is electrically coupled with the plate; and
a plurality of connectors, comprising electrical connectors for the heater element and electrical connectors for the electrodes; each of the electrical connectors for the plurality of electrodes comprising:
an inner conductor
an insulating layer about the inner conductor,
a ground tube about the insulating layer, and
a ceramic tube about the ground tube; and

a base comprising:
an electrically conductive base housing that is electrically coupled with the shaft housing; and
an electrically insulating terminal block disposed within the base housing, the plurality of connectors passing through the terminal block.

2. The wafer chuck assembly of claim 1 , the terminal block comprising polyether ether ketone.

3. The wafer chuck assembly of claim 1 , the connectors further comprising one or more connectors for a thermocouple or a resistance temperature detector.

4. The wafer chuck assembly of claim 1 , the connectors further comprising one or more fluid conduits.

5. The wafer chuck assembly of claim 4 , at least one of the one or more fluid conduits being configured to provide a heat transfer gas, the top surface defining channels for the heat transfer gas to spread between the top surface and a bottom surface of a wafer.

6. The wafer chuck assembly of claim 1 , further comprising a wafer processing system in which the wafer chuck assembly is disposed.

7. The wafer chuck assembly of claim 6 , wherein the wafer processing system comprises:
a process chamber bounded by one or more chamber walls, and
one or more power supplies;
wherein the wafer chuck assembly is disposed such that at least the puck is within the process chamber; and
the one or more power supplies couple with the plurality of electrodes and at least one of the one or more chamber walls to provide:
an RF voltage between the electrodes and the at least one of the one or more chamber walls; and
a DC voltage differential across the electrodes, for electrostatically clamping a wafer to the top surface.

8. The wafer chuck assembly of claim 6 , wherein the electrically conductive plate is separated from the electrically insulating material by a gap of 0.5 to 1.5 millimeters, and wherein the wafer processing system is configured to provide a purge gas within the gap.

9. The wafer chuck assembly of claim 8 , wherein the purge gas is one of helium and hydrogen, and the purge gas provides a positive pressure within the gap with respect to a surrounding process chamber.

10. The wafer chuck assembly of claim 1 , wherein the electrically conductive base housing defines one or more channels for a cooling fluid.

11. The wafer chuck assembly of claim 10 , the electrically conductive shaft housing comprising metal of at least 1.5 mm thickness, for removal of heat from the electrically conductive plate, through the shaft housing, to the base housing.

12. The wafer chuck assembly of claim 1 , wherein the ceramic tube extends continuously from the terminal block to a bottom surface of the puck.

13. A wafer chuck assembly, comprising:
a puck comprising:
an electrically insulating material defining a top surface of the puck;
a DC probe that extends through the top surface of the puck;
a heater element embedded within the electrically insulating material;
a plurality of electrodes embedded within the electrically insulating material and disposed between the heater element and the top surface; and
an electrically conductive plate disposed proximate to the electrically insulating material;
a shaft comprising:
an electrically conductive shaft housing that is electrically coupled with the plate; and
a plurality of connectors comprising:
electrical connectors for the heater element,
electrical connectors for the electrodes; and
a connector for the DC probe;

a base comprising:
an electrically conductive base housing that is electrically coupled with the shaft housing; and
an electrically insulating terminal block disposed within the base housing, the plurality of connectors passing through the terminal block;
and further comprising:
a wafer processing system in which the wafer chuck assembly is disposed, the wafer processing system comprising:
a process chamber bounded by one or more chamber walls, and
one or more power supplies;
wherein the wafer chuck assembly is disposed such that at least the puck is within the process chamber; and
the one or more power supplies couple with the plurality of electrodes and at least one of the one or more chamber walls to provide:
an RF voltage between the electrodes and the at least one of the one or more chamber walls; and
a DC voltage differential across the electrodes, for electrostatically clamping a wafer to the top surface.

14. The wafer chuck assembly of claim 13 , wherein a power supply of the one or more power supplies adjusts a DC offset between at least one of the electrodes and the at least one of the one or more chamber walls in response to a signal from the DC probe.

Assignees

• Applied Materials Inc

Inventors

• Tran Toan Q
• Malik Sultan
• Lubomirsky Dmitry
• Roy Shambhu N
• Kobayashi Satoru
• Cho Tae Seung
• Park Soonam
• Venkataraman Shankar

Classifications

• H10P72/0432 Primary

  mainly by conduction · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H01L21/3065

  Electricity · mapped topic

• H01L21/6833 Primary

  Electricity · mapped topic