Monitoring method of processing state and processing unit

• US 20040197938A1
• Filed: 06/01/2004
• Published: 10/07/2004
• Est. Priority Date: 09/02/2002
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Saito, Susumu
• Granted Patent: US 7,329,549 B2
• Time in Patent Office: Days
• US Class Current: 438/9
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/31116 by dry-etching

Abstract

The present invention is a monitoring method of monitoring a change of a processing state of an object to be processed when a predetermined process is conducted to the object to be processed by using a processing unit. The method includes: a step of respectively setting constant response variables for two states before and after a processing state changes, the response variables being different from each other; and a step of conducting a multiple regression analysis about the response variables in order to produce a model expression, predictor variables of the multiple regression analysis being a plurality of detected data from a plurality of detectors provided in the processing unit. Then, the method includes: a step of actually obtaining a plurality of detected data from the plurality of detectors when the predetermined process is conducted to the object to be processed; and a step of estimating or monitoring a processing state by applying the obtained plurality of detected data to the model expression.

Claims

1. A monitoring method of monitoring a change of a processing state of an object to be processed when a predetermined process is conducted to the object to be processed by using a processing unit, the monitoring method comprising:

a step of respectively setting constant response variables for two states before and after a processing state changes, the response variables being different from each other;

a step of conducting a multiple regression analysis about the response variables in order to produce a model expression, predictor variables of the multiple regression analysis being a plurality of detected data from a plurality of detectors provided in the processing unit;

a step of actually obtaining a plurality of detected data from the plurality of detectors when the predetermined process is conducted to the object to be processed; and

a step of estimating or monitoring a processing state by applying the obtained plurality of detected data to the model expression.

2. A method according to claim 1, wherein

the processing unit is a plasma processing unit.

3. A method according to claim 2, wherein

the plurality of detected data are emission intensities of a plurality of component wavelengths of plasma.

4. A method according to claim 3, wherein

the emission intensities of a plurality of component wavelengths of plasma change depending on the two states.

5. A method according to claim 2, wherein

the two states are a state on the way of an etching process and a state after a completion of the etching process.

6. A processing unit for conducting a predetermined process to an object to be processed, the processing unit comprising:

a plurality of detectors; and

a controlling unit that estimates or monitors a processing state based on a plurality of detected data from the plurality of detectors,

wherein the controlling unit includes;

a first storage unit that stores the plurality of detected data;

a second storage unit that stores constant response variables respectively set for two states before and after the processing state changes, the response variables being different from each other;

a third storage unit that stores a multivariate analysis program, according to which a multiple regression analysis about the response variables is conducted in order to produce a model expression, predictor variables of the multiple regression analysis being the plurality of detected data;

a first computing unit that executes the multivariate analysis program to produce the model expression;

a fourth storage unit that stores the produced model expression;

a second computing unit that applies the plurality of detected data to the model expression in order to estimate or monitor the processing state, the plurality of detected data being detected when the predetermined process is conducted to the object to be processed.

7. A processing unit according to claim 6, wherein

the processing unit is a plasma processing unit.

8. A processing unit according to claim 7, wherein

the plurality of detectors are optical detectors that detect emission intensities of a plurality of component wavelengths of plasma.