Semiconductor Processing System With Integrated Showerhead Distance Measuring Device

• US 20080246493A1
• Filed: 03/26/2008
• Published: 10/09/2008
• Est. Priority Date: 04/05/2007
• Status: Abandoned Application

• Current Assignee: CyberOptics Semiconductor, Inc. (Nordson Corporation)
• Original Assignee: CyberOptics Semiconductor, Inc. (Nordson Corporation)
• Inventors: Gardner, DelRae H.
• Application Number:
  US12/055,744
• Publication Number:
  US 20080246493A1
• Time in Patent Office: Days
• US Class Current: 324/662
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45589 Movable means, e.g. fans
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection

Abstract

A system for determining a distance between a showerhead of a semiconductor processing system and a substrate-supporting pedestal is provided. The system includes a showerhead having a showerhead surface from which reactive gas is expelled and a pedestal having a pedestal surface that faces the showerhead surface. A first capacitive plate is disposed on the pedestal surface. A second capacitive plate is disposed on the showerhead surface. A third capacitive plate disposed on one of the showerhead surface and the pedestal surface, but spaced from the first and second capacitive plates. Capacitance measurement circuitry is operably coupled to the first, second and third capacitive plates.

Claims

1. A system for determining a distance between a showerhead of a semiconductor processing system and a substrate-supporting pedestal, the system comprising:

a showerhead having a showerhead surface from which reactive gas is expelled;

a pedestal having a pedestal surface that faces the showerhead surface;

a first capacitive plate disposed on the pedestal surface;

a second capacitive plate disposed on the showerhead surface;

a third capacitive plate disposed on one of the showerhead surface and the pedestal surface, but spaced from the first and second capacitive plates; and

capacitance measurement circuitry operably coupled to the first, second and third capacitive plates.

2. The system of claim 1, wherein the third capacitive plate is disposed on the showerhead surface.

3. The system of claim 1, wherein the showerhead is circular, and wherein at least one of the second and third plates is also circular.

4. The system of claim 1, wherein the capacitive measurement circuitry provides an indication of capacitance between the first and second plates and between the first and third plates.

5. The system of claim 1, and further comprising:

a controller;

a source of RF energy;

a first switch coupling the source of RF energy to one of the substrate-supporting pedestal and the showerhead;

a second switch coupling the capacitance measurement circuitry to one of the substrate supporting pedestal and the showerhead; and

wherein the controller is coupled to the source of RF energy, the capacitance measurement circuitry and the first and second switches to engage the RF energy source and close the first switch during a normal operating mode, and to engage the capacitance measurement circuitry and close the second switch during a measurement mode.

6. The system of claim 5, wherein the first and second switches are operated opposite of each other, such that when the first switch is closed, the second switch is open, and when the second switch is closed, the first switch is open.

7. The system of claim 5 and further comprising a third switch operably coupling the second capacitive plate to the first and second switches.

8. The system of claim 7 and further comprising a fourth switch operably coupling the third capacitance plate to the first and second switches.

9. A method of measuring electrode separation in a semiconductor processing chamber having a first and second surfaces between which a semiconductor is processed, the method comprising:

providing first and second capacitive plates on one of the first and second surfaces, which first and second capacitive plates are spaced and isolated from one another;

providing a third capacitive plate on the other of the first and second surfaces; and

measuring the capacitance between the first and third capacitive plate and measuring the capacitances between the second and third capacitive plate, and providing an indication of separation based upon the measured capacitances.

10. The method of claim 9, wherein the indication of separation is an overall indication of separation between the first and second surfaces.

11. The method of claim 10, wherein the indication of separation is used to adjust the separation.

12. The method of claim 9, wherein the indication of separation is used to provide an indication of parallelism.

13. The method of claim 12 and further comprising adjusting parallelism of the surfaces relative to one another based upon the parallelism indication.

14. The method of claim 9, wherein the indication of the separation is used to provide a measure of electrode shape.

15. A showerhead for use in a semiconductor processing system, the showerhead comprising:

a plurality of conductive regions, in which each region is electrically isolated from other regions.

16. The showerhead of claim 15, wherein the plurality of conductive regions are substantially co-planar.

17. The showerhead of claim 15 and further comprising a capacitance measurement circuit operably coupled to each conductive region.