Manufacturing Process End Point Detection

• US 20080221720A1
• Filed: 03/07/2007
• Published: 09/11/2008
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Hendler, Lawrence, Richter, Matthew
• Granted Patent: US 7,630,786 B2
• Time in Patent Office: Days
• US Class Current: 700/109
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

A method for identifying a predetermined state of a manufacturing process by monitoring the process which involves, monitoring a plurality of variables that vary in value during the manufacturing process. The method also involves mapping as points in a hyperspace the values of each variable at a plurality of times, where the hyperspace has a number of dimensions equal to the number of variables and the number of points is equal to the plurality of times. The method also involves identifying that a manufacturing process has reached the predetermined state when one of the points reaches a closed volume in the hyperspace that is located within a predefined distance from a predefined location in the hyperspace.

Claims

1. A method for identifying a predetermined state of a manufacturing process by monitoring the process, comprising:

monitoring a plurality of variables that vary in value during the manufacturing process;

mapping as points in a hyperspace the values of each variable at a plurality of times, where the hyperspace has a number of dimensions equal to the number of variables and the number of points is equal to the plurality of times; and

identifying that the manufacturing process has reached the predetermined state when one of the points reaches a closed volume in the hyperspace that is located within a predefined distance from a predefined location in the hyperspace.

2. The method of claim 1, wherein the predetermined state represents that the manufacturing process has completed the manufacturing of the product.

3. The method of claim 1, wherein the predetermined state represents that the manufacturing process has reached an intermediate state.

4. The method of claim 1, comprising calculating the distance of each point relative to the predefined location.

5. The method of claim 1, comprising using a transformation method to transform a model of the manufacturing process in hyperspace into a line, the predefined location in the hyperspace onto the line, and the points in hyperspace onto the line, wherein the manufacturing process has reached the predetermined state when one of the transformed points reaches a location on the line that is located within a second predefined distance from the predefined location on the line.

6. The method of claim 1, comprising using a multivariate analysis method to project the points in the hyperspace in to a lower order hyperspace and the predefined location in the hyperspace in to the lower order hyperspace, wherein the manufacturing process has reached the predetermined state when one of the points reaches a location in the lower order hyperspace that is located within a second predefined distance from the predefined location in the lower order hyperspace.

7. The method of claim 6, comprising using a transformation method to transform the dimensions of the lower order hyperspace into a line, transform the predefined location in the lower order hyperspace onto the line, and transform the points in the lower order hyperspace onto the line, wherein the manufacturing process has reached the predetermined state when one of the transformed points in the lower order hyperspace reaches a location on the line that is located within a second predefined distance from the predefined location on the line.

8. The method of claim 1, comprising modifying a location of the closed volume in the hyperspace based on testing a completed product.

9. The method of claim 1, comprising modifying the predefined distance based on testing a completed product.

10. The method of claim 1, comprising acquiring sensor data regarding the at least one variable.

11. The method of claim 9, wherein the sensor data is acquired using at least one of a Fourier transform infrared spectrometer, a pressure sensor or a temperature sensor.

12. The method of claim 1, comprising controlling the manufacturing process based on a location of at least one of the points in hyperspace.

13. A system for identifying a predetermined state of a manufacturing process by monitoring the process, comprising:

means for monitoring a plurality of steps for manufacturing a product wherein each step is defined by at least one variable that varies in value during the manufacturing process;

means for mapping as points in a hyperspace the values of each variable at a plurality of times, where the hyperspace has a number of dimensions equal to the number of variables and the number of points is equal to the plurality of times; and

means for identifying that the manufacturing process has reached a predetermined state when one of the points reaches a closed volume in the hyperspace that is located within the predefined distance from a predefined location in the hyperspace.

14. A computer program product, tangibly embodied in an information carrier, the computer program product including instructions being operable to cause data processing apparatus to:

monitor a plurality of steps for manufacturing a product wherein each step is defined by at least one variable that varies in value during the manufacturing process;

map as points in a hyperspace the values of each variable at a plurality of times, where the hyperspace has a number of dimensions equal to the number of variables and the number of points is equal to the plurality of times; and

identify that the manufacturing process has reached a predetermined state when one of the points reaches a closed volume in the hyperspace that is located within a predefined distance from a predefined location in the hyperspace.