APPARATUS TO DETECT FAULT CONDITIONS OF A PLASMA PROCESSING REACTOR

• US 20110022215A1
• Filed: 10/05/2010
• Published: 01/27/2011
• Est. Priority Date: 06/07/2006
• Status: Abandoned Application

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Kimball, Chris, Hudson, Eric, Fischer, Andreas, Keil, Douglas
• Application Number:
  US12/898,342
• Publication Number:
  US 20110022215A1
• Time in Patent Office: Days
• US Class Current: 700/110
• CPC Class Codes: C23C 16/509 using internal electrodes
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A method of fault detection for use in a plasma processing chamber is provided. The method comprises monitoring plasma parameters within a plasma chamber and analyzing the resulting information. Such analysis enables detection of failures and the diagnosis of failure modes in a plasma processing reactor during the course of wafer processing. The method comprises measuring the plasma parameters as a function of time and analyzing the resulting data. The data can be observed, characterized, compared with reference data, digitized, processed, or analyzed in any way to reveal a specific fault. Monitoring can be done with a detector such as a probe, which is preferably maintained within the plasma chamber substantively coplanar with a surface within the chamber, and directly measures net ion flux and other plasma parameters. The detector is preferably positioned at a grounded surface within the reactor such as a grounded showerhead electrode, and can be of a planar ion flux probe (PIF) type or a non-capacitive type. Chamber faults that can be detected include a build-up of process by-products in the process chamber, a helium leak, a match re-tuning event, a poor stabilization rate, and a loss of plasma confinement. If the detector is a probe, the probe can be embedded in a part of a plasma processing chamber and can comprises one or more gas feed-through holes.

Claims

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16. An apparatus for monitoring a plasma process wherein a plasma process is initiated within a plasma chamber, plasma parameter data on the plasma process is obtained by use of a planar ion flux (PIF) probe wherein a sensing surface of the probe is exposed to the plasma and is coextensive with a wall or component surface within the plasma chamber, and the plasma parameter data is evaluated for indications of a fault condition, wherein (a) the probe is embedded in the wall or in any of the following components of a plasma processing chamber:

a showerhead electrode, a liner, a confinement ring, a focus ring, an electrode without gas outlets, a gas distribution plate and a substrate support, (b) the probe is heated by use of a temperature control component, (c) the probe is capable of compensating for differential wear rate between a sensing surface of the probe and an adjacent and surrounding surface of a chamber component in which the probe is embedded and/or (d) the probe is embedded in any of a capacitively coupled plasma processing chamber, an inductively-coupled plasma processing chamber and an electron cyclotron resonance plasma processing chamber.

17. The apparatus of claim 16, wherein the PIF probe is embedded in the inner or outer electrode part of a multi-piece showerhead electrode assembly.

18. The apparatus of claim 16, wherein the probe is located in a showerhead electrode and the probe comprises one or more gas feed-through holes creating a gas passage from the sensing surface, through, to the back surface of the probe and (a) the gas feed-through holes are positioned to approximate the overall gas distribution pattern that would exist in the absence of the probe or (b) the gas feed-through holes are positioned in the probe where they would otherwise be located in the showerhead electrode in the absence of the probe.

21. The apparatus of claim 16, further comprising a detection system which stores the plasma parameter data on a computer-readable storage medium system, filters the plasma parameter data, subjects the plasma parameter data to an algorithm, subjects the plasma parameter data to a mathematical operation, and compares the plasma parameter data to existing reference data, which results in an interpretation;

and, the issuance of a status report and/or warning based on the interpretation.

22. The apparatus of claim 16, wherein the probe is positioned in a recess extending into a radio frequency biased surface or at a grounded surface.

23. The apparatus of claim 16, wherein the probe includes a temperature control component operable to heat or cool the probe.

24. The apparatus of claim 16, wherein (a) the probe is operable to collect the plasma parameter data as a series of measurements during the course of processing a wafer, (b) collect post-RF ramp plasma density data and/or (c) identify a random retuning of an RF matching system of the plasma chamber.

25. The apparatus of claim 16, wherein the probe is operable to detect (a) a change in the slope of the post-RF ramp plasma density data is used to indicate the plasma chamber fault condition is a build-up of process by-products in the process chamber, (b) an oscillation of the plasma density after an RF ramp of between about 5% and about 20% of the absolute value of the plasma density is used to indicate that the plasma chamber fault condition is a helium leak and/or (c) an oscillation of the plasma density of amplitude less than 5% of the absolute value of the plasma density and of duration less than 5 seconds, occurring after the RF ramp, is used to indicate that the plasma chamber fault condition is a random re-tuning of the matching system.

26. The apparatus of claim 21, wherein (a) the status report and/or warning initiates a corrective step in the system, (b) the status report and/or warning records the interpretation in a log containing wafer history and/or (c) the status report and/or warning stops the processing of a wafer in the plasma chamber.

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