Ozone system for multi-chamber tools

• US 8,480,862 B2
• Filed: 01/18/2011
• Issued: 07/09/2013
• Est. Priority Date: 07/07/2005
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Berkman, Vitaly J., Ryan, Thomas J.
• Primary Examiner(s): Mayekar, Kishor
• Application Number:
  US13/008,641
• Publication Number:
  US 20110108122A1
• Time in Patent Office: 903 Days
• Field of Search: 204/176, 116/264
• US Class Current: 204/176
• CPC Class Codes: C01B 13/11 by electric discharge
• CPC Class Codes: C01B 2201/40 using several dischargers in series
• CPC Class Codes: C01B 2201/64 Oxygen
• CPC Class Codes: C01B 2201/90 Control of the process
• CPC Class Codes: G05D 11/138 by sensing the concentration of the mixture, e.g. measuring pH value
• CPC Class Codes: Y10T 137/0318 Processes

Abstract

An improved system and method for controlling ozone concentration in connection with a multi-chamber tool. The system and method involve a first and a second concentration controller in combination with an ozone generator. The first concentration controller detects an EVENT (i.e., one of the chambers in the multi-chamber tool coming on-line or off-line) and in response provides a power instruction to the ozone generator in accordance with a predictive control algorithm. The first concentration controller has a fast (i.e, about 1 second) response time. The second concentration controller is masked from the ozone generator during the EVENT, but otherwise controls the generator after an interval of time has lapsed after the EVENT. The second concentration controller has a slower response time than the first concentration controller, however the second concentration controller provides the system with long-term stability and can be used to provide updated data to the predictive control algorithm.

Claims

1. A method of controlling a flow of a gas comprising:

introducing a flow of the gas to a first chamber at a concentration;

introducing the flow of the gas to a second chamber; and

using a predetermined value to adjust production of the gas such that the concentration of the gas in the first chamber remains substantially unchanged and the second chamber receives a concentration of the gas substantially the same as the concentration delivered to the first chamber after an interval of time, the interval of time being less than about 15 seconds.

2. The method of claim 1, wherein the interval of time is less than about 10 seconds.

3. The method of claim 1, wherein the gas is ozone produced in an ozone generator.

4. The method of claim 3 further comprising using the predetermined value to change power delivered to the ozone generator used to produce the flow of ozone.

5. The method of claim 1 further comprising determining the predetermined value using a predictive control algorithm.

6. A method of controlling a flow of ozone, comprising:

introducing a flow of ozone to a first chamber at a concentration;

introducing the flow of ozone to a second chamber;

adjusting a power level delivered to an ozone generator to change a rate of production of ozone to maintain a concentration of ozone in the second chamber at a value substantially the same as the concentration of ozone in the first chamber after an interval of time;

storing in memory the power level delivered; and

using the power level as a reference during a subsequent adjustment.