Plasma processing apparatus and plasma processing method

• US 20040173309A1
• Filed: 03/04/2003
• Published: 09/09/2004
• Est. Priority Date: 03/04/2003
• Status: Active Grant

• Current Assignee: Go Miya, Hideyuki Yamamoto, Hiroyuki Kitsunai, Junichi Tanaka, Toshio Masuda
• Original Assignee: Go Miya, Hideyuki Yamamoto, Hiroyuki Kitsunai, Junichi Tanaka, Toshio Masuda
• Inventors: Tanaka, Junichi, Miya, Go, Yamamoto, Hideyuki, Kitsunai, Hiroyuki, Masuda, Toshio
• Granted Patent: US 7,147,747 B2
• Time in Patent Office: Days
• US Class Current: 156/345.24
• CPC Class Codes: G01N 21/73 using plasma burners or torches
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H05H 1/0037 by spectrometry

Abstract

In a plasma processing apparatus including: a process chamber 3; a light-receiving part 11 for receiving a plasma emission; a spectrometer unit 13 for performing a spectrometry on the plasma emission to convert the same into a multi-channel signal; a signal converting unit 14 for converting the multi-channel signal into one signal using a filter vector stored in a database 15; and a processing unit 16 for determining a condition in the process chamber based on the resulting signal, the condition in the process chamber is determined in such a manner that differences between principal component scores derived from plasma emission data on a lot of substrates by multivariate analysis and principal component scores for the preceding lot of substrates are found, an average value of the differences in one lot, a difference between a maximum and a minimum of the differences in one lot and a standard deviation of the differences in one lot are determined, and the values are compared with a preset threshold.

Claims

1. A plasma processing apparatus having a process chamber in which an object to be processed is subjected to a plasma processing, comprising:

a light-receiving part for monitoring a plasma emission in said process chamber;

a spectrometer unit for performing a spectrometry on said plasma emission to convert the same into a multi-channel signal;

an arithmetic unit for converting said multi-channel signal into one or more output signals and performing an arithmetic operation on the output signals;

a database for storing a filter vector;

a determination unit for determining a condition in the process chamber based on a result of said arithmetic operation; and

an apparatus controller for controlling an operation of said plasma processing apparatus in response to a signal from said determination unit.

2. The plasma processing apparatus according to claim 1, wherein the conversion of said multi-channel signal into one or more signals by said arithmetic unit is performed using a multivariate analysis.

3. The plasma processing apparatus according to claim 1, wherein the conversion by said arithmetic unit is performed using the filter vector.

4. The plasma processing apparatus according to any one of claims 1 to 3, wherein the determination of the condition in the process chamber by said arithmetic unit is performed in such a manner that one or more differences between said one or more output signals derived from a batch of plasma emission data by multivariate analysis and one or more output signals derived from the preceding batch of plasma emission data are found, an average value of the differences in one batch, a difference between a maximum and a minimum of the differences in one batch and a standard deviation of the differences in one batch are determined, and the values are compared with a preset threshold.

5. The plasma processing apparatus according to any one of claims 1 to 3, wherein the determination of the condition in the process chamber by said arithmetic unit is performed in such a manner that one or more differences between said one or more output signals derived from a batch of plasma emission data by multivariate analysis and one or more output signals derived from the preceding batch of plasma emission data are found, an average value of the differences in one batch, a difference between a maximum and a minimum of the differences in one batch and a standard deviation of the differences in one batch are determined, the values are compared with a plurality of preset thresholds to calculate a point for each of the values, and the sum of the points is compared with a preset threshold.

6. The plasma processing apparatus according to any one of claims 1 to 5, wherein the determination of the condition in said process chamber is determination that an end point of the seasoning is reached.

7. The plasma processing apparatus according to any one of claims 1 to 6, wherein the conversion of said multi-channel signal into one or more signals by said arithmetic unit is performed using a principal component analysis.

8. A plasma processing method using a plasma processing apparatus having:

a process chamber in which a substrate is subjected to a plasma processing;

a light-receiving part for monitoring a plasma emission in the process chamber;

a spectrometer unit for performing a spectrometry on the received plasma emission to convert the same into a multi-channel signal;

an arithmetic unit for converting the multi-channel signal into one or more output signals and performing an arithmetic operation on the output signals;

a database for storing a filter vector;

a determination unit for determining a condition in the process chamber based on a result of the arithmetic operation; and

an apparatus controller for controlling an operation of the plasma processing apparatus in response to a signal from the determination unit,

the method comprising;

a step of converting the multi-channel signal output from the spectrometer unit into a batch of output signals;

a step of finding differences between the output signals and output signals of the preceding batch; and

a step of comparing an average value of the differences in one batch, a difference between a maximum and a minimum of the differences in one batch and a standard deviation of the differences in one batch with a preset threshold.

9. A plasma processing method using a plasma processing apparatus having:

a process chamber in which a substrate is subjected to a plasma processing;

a light-receiving part for monitoring a plasma emission in the process chamber;

a spectrometer unit for performing a spectrometry on the received plasma emission to convert the same into a multi-channel signal;

an arithmetic unit for converting the multi-channel signal into one or more output signals and performing an arithmetic operation on the output signals;

a database for storing a filter vector;

a determination unit for determining a condition in the process chamber based on a result of the arithmetic operation; and

an apparatus controller for controlling an operation of the plasma processing apparatus in response to a signal from the determination unit,

the method comprising;

a step of performing evacuation after a wet cleaning;

a step of automatically determining whether a degree of vacuum is adequate or not;

a step of automatically determining whether there is an apparatus abnormality or not;

a step of converting the multi-channel signal output from the spectrometer unit into a batch of output signals;

a step of finding differences between the output signals and output signals of the preceding batch; and

a step of comparing an average value of the differences in one batch, a difference between a maximum and a minimum of the differences in one batch and a standard deviation of the differences in one batch with a preset threshold.