ESC assembly including an electrically conductive gasket for uniform RF power delivery therethrough

Patent metadata

Field	Value
Publication number	US-10002782-B2
Application number	US-201414517095-A
Country	US
Kind code	B2
Filing date	Oct 17, 2014
Priority date	Oct 17, 2014
Publication date	Jun 19, 2018
Grant date	Jun 19, 2018

Abstract

A substrate processing apparatus for processing substrates comprises a processing chamber in which a substrate is processed. A process gas source is adapted to supply process gas into the processing chamber. A RF energy source is adapted to energize the process gas into a plasma state in the processing chamber. A vacuum source is adapted to exhaust byproducts of the processing from the processing chamber. The processing chamber includes an electrostatic chuck assembly having a layer of ceramic material that includes an upper electrostatic clamping electrode and at least one RF electrode, a temperature controlled RF powered baseplate, and at least one annular electrically conductive gasket extending along an outer portion of an upper surface of the temperature controlled RF powered baseplate. The at least one annular electrically conductive gasket electrically couples the upper surface of the temperature controlled RF powered baseplate to the at least one RF electrode.

First claim

What is claimed is:

1. A processing apparatus for processing a semiconductor substrate, the processing apparatus comprising:
a processing chamber in which the semiconductor substrate is processed;
a process gas source in fluid communication with the processing chamber and adapted to supply process gas into the processing chamber;
a RF energy source adapted to energize the process gas into a plasma state in the processing chamber;
a vacuum source adapted to exhaust process gas and byproducts from the processing chamber during the processing of the semiconductor substrates; and
an electrostatic chuck assembly comprising
a layer of ceramic material including an electrostatic clamping (ESC) electrode and at least one RF electrode below the ESC electrode, wherein the at least one RF electrode and the ESC electrode are embedded in the layer of ceramic material,
a temperature controlled RF powered baseplate,
a bond layer disposed between the layer of ceramic material and the temperature controlled RF powered baseplate, wherein the bond layer bonds the temperature controlled RF powered baseplate to the layer of ceramic material, and
at least one annular electrically conductive gasket extending along an upper surface of the temperature controlled RF powered baseplate and through the bond layer, wherein the at least one annular electrically conductive gasket electrically couples the upper surface of the temperature controlled RF powered baseplate to the RF electrode, wherein the layer of ceramic material includes a support surface adapted to electrostatically clamp a semiconductor substrate during processing of the semiconductor substrate, and
wherein RF power is provided from the temperature controlled RF powered baseplate to the at least one RF electrode by the at least one annular electrically conductive gasket.

2. The processing apparatus of claim 1 , wherein:
the at least one annular electrically conductive gasket comprises an outer annular electrically conductive gasket and an inner annular electrically conductive gasket both of which extend in the bond layer; and
the inner annular electrically conductive gasket is disposed radially inward of the outer annular electrically conductive gasket.

3. The processing apparatus of claim 2 , wherein the inner annular electrically conductive gasket and the outer annular electrically conductive gasket are disposed in the bond layer and between the temperature controlled RF powered baseplate and the layer of ceramic material.

4. The processing apparatus of claim 2 , wherein the at least one annular electrically conductive gasket comprises one or more intermediate annular electrically conductive gaskets disposed between the outer annular electrically conductive gasket and the inner annular electrically conductive gasket.

5. The processing apparatus of claim 1 , wherein the layer of ceramic material includes a stepped portion extending along a circumference of the layer of ceramic material.

6. The processing apparatus of claim 5 , wherein the at least one RF electrode comprises:
an inner RF electrode disposed below the ESC electrode and electrically coupled to the upper surface of the temperature controlled RF powered baseplate by a first annular electrically conductive gasket; and
an outer annular RF electrode disposed underneath the stepped portion and electrically coupled to the upper surface of the temperature controlled RF powered baseplate by a second outer annular electrically conductive gasket.

7. The processing apparatus of claim 6 , wherein:
the inner RF electrode is electrically coupled to the upper surface of the temperature controlled RF powered baseplate by a first plurality of vertical electrically conductive vias; and
a second plurality of vertical electrically conductive vias electrically couple the outer annular RF electrode to the inner RF electrode.

8. The processing apparatus of claim 1 , wherein:
the layer of ceramic material includes a plurality of vertical electrically conductive vias; and
the vertical electrically conductive vias electrically connect the at least one RF electrode to the at least one annular electrically conductive gasket or an annular electrical contact in the layer of ceramic material.

9. The processing apparatus of claim 1 , wherein the at least one annular electrically conductive gasket is a spiral gasket.

10. The processing apparatus of claim 1 , wherein:
(a) the electrostatic chuck assembly further comprises
at least one outlet in the support surface, which delivers a heat transfer gas to an underside of the semiconductor substrate, and
at least one gas passage in the layer of ceramic material connected to a source of the heat transfer gas and operable to supply the heat transfer gas at a predetermined pressure to the at least one gas passage;

(b) the bond layer is formed by an elastomeric material;
(c) the electrostatic chuck assembly further comprises lift pins operable to lower the semiconductor substrate onto the support surface of the electrostatic chuck assembly and to raise the semiconductor substrate from the support surface of the electrostatic chuck assembly;
(d) the ESC electrode is a monopolar or bipolar ESC electrode;
(e) the layer of ceramic material includes a plurality independently controlled heaters operable to heat independently controllable zones;
(f) the at least one annular electrically conductive gasket comprises a segmented gasket;
(g) the ESC electrode includes a pattern of an electrically conductive material;
(h) the at least one RF electrode includes a pattern of an electrically conductive material;
(i) a lower surface of the layer of ceramic material includes at least one circumferentially extending channel;
(j) an upper portion of each of the at least one annular electrically conductive gasket is disposed in a respective channel of the at least one circumferentially extending channel;
(k) the lower surface of the layer of ceramic material includes an outer peripheral step;
(l) the outer peripheral step extends around an outer periphery of the lower surface of the layer of ceramic material; and
(m) an upper portion of an annular electrically conductive gasket of the at least one annular electrically conductive gasket is disposed in the outer peripheral step.

11. The processing apparatus of claim 1 , further comprising:
a control system configured to control processes performed by the processing apparatus; and
a non-transitory computer machine-readable medium comprising program instructions for controlling the processing apparatus.

12. The processing apparatus of claim 1 , wherein:
the temperature controlled RF powered baseplate includes an upper layer of dielectric insulating material and an outer layer of dielectric insulating material;
the dielectric insulating material is disposed on the upper surface of the temperature controlled RF powered baseplate and is adapted to reduce arcing between the semiconductor substrate and the temperature controlled RF powered baseplate; and
the outer layer of dielectric insulating material is disposed on an outer surface of the temperature controlled RF powered baseplate and is adapted to reduce arcing between the semiconductor substrate and the temperature controlled RF powered baseplate, wherein regions of the upper surface of the temperature controlled RF powered baseplate which contact the at least one annular electrically conductive gasket do not include the dielectric insulating material.

13. A method of processing the semiconductor substrate in the processing apparatus of claim 1 , the method comprising:
supporting the semiconductor substrate on the supp

Assignees

• Lam Res Corp

Inventors

• Kimball Christopher
• Gaff Keith
• Matyushkin Alexander
• Chen Iii Zhigang
• Comendant Keith

Classifications

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H01J37/32715

  Workpiece holder · CPC title

• H01J37/32724

  Temperature · CPC title

• H01J37/32568

  Relative arrangement or disposition of electrodes; moving means · CPC title

• H01L21/6833 Primary

  Electricity · mapped topic