JP2002313729A - Method of monitoring plasma processor, plasma processing method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the impedance change of a high frequency power line for a plasma processor is detected from the reduction of a film forming rate/etching rate requiring much time for detecting the condition change of the processor. SOLUTION: A voltage measuring terminal 6 is disposed on the processor and the change of a measured voltage waveform is monitored, using a means 7 for connecting with the measuring terminal 6, a means 8 for measuring the voltage waveform, and a means 9 for storing the measured voltage waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for monitoring the state of a plasma processing apparatus, a plasma processing method and a plasma processing apparatus.

[0002]

2. Description of the Related Art An example of a conventional state monitoring method for a plasma processing apparatus will be described below with reference to FIG.
In FIG. 5, 1 is a vacuum chamber, 2 is a ground side electrode, 3 is a high frequency application side electrode, 4 is a high frequency matching device, 5 is a high frequency power supply,
In this plasma processing apparatus, a method of monitoring an output signal from a Vdc / Vpp detection circuit mounted on the high-frequency matching device 4 for monitoring a state, and using a high voltage probe to measure the voltage of the portion shown in FIG. And a method of measuring a film thickness after film formation and calculating a film formation rate, a method of monitoring a time until completion of etching, and calculating an etching rate, and the like.

[0003]

SUMMARY OF THE INVENTION A vacuum chamber, a door, a cover,
The conductive path of high-frequency power composed of ducts, etc., is designed to have a large contact area in order to minimize impedance, but the state changes due to deterioration due to opening and closing of the door, aging, and improper mounting of parts, etc. I do.

[0004] However, the resistance value cannot be detected by measuring the resistance value using a tester, and it has been difficult to confirm the impedance with respect to the high-frequency power used in the device.

In the above conventional method, the film forming rate /
In order to detect a decrease in the etching rate, it takes time to detect a change in the state of the apparatus. Also, rate, Vdc / Vp
Even if a change in the state of the plasma processing apparatus can be detected by monitoring p, it is difficult to identify the cause of the change in the state, and it takes time to solve the problem.

[0006]

According to the present invention, there is provided a plasma processing apparatus comprising:
The voltage waveform of the part installed from the voltage measurement terminal installed in the plasma processing apparatus is measured, the measured voltage waveform is stored, and the stored voltage waveform and the measured voltage waveform are compared and determined. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a state monitoring method according to the present invention will be described below with reference to FIG.

FIG. 1 shows a configuration of a plasma processing apparatus according to an embodiment of the present invention, wherein 1 is a vacuum chamber, 2 is a ground electrode, 3 is a high frequency application electrode, 4 is a high frequency matching device, and 5 is a high frequency Power supply.

In order to monitor the state of the device, a voltage measuring terminal 6 disposed on the ground potential side of the device, a means 7 for connecting to the voltage measuring terminal 6, a voltage waveform measuring means 8 for measuring a voltage waveform,
A voltage waveform storage means 9 for storing the measured voltage waveform is provided, and a means 10 for displaying the measured voltage waveform is provided.

In an initial state of the apparatus, high-frequency power is applied under predetermined recipe conditions. At this time, since an impedance is generated between the voltage measuring terminals 6 on the ground side disposed on the vacuum chamber 1, a potential difference is generated. This is measured using a means 7 for connecting to a voltage measuring terminal 6 and a voltage waveform measuring means 8,
This voltage waveform is stored in the voltage waveform storage means 9. Then, before the start of production, at the time of maintenance, or the like, high-frequency power is applied under the same conditions as when measuring in the initial state of the apparatus, and the same voltage waveform between the voltage measuring terminals 6 is measured. A means 10 for displaying a voltage waveform in an initial state of the apparatus which has been measured and stored in advance;
By comparing the measured waveform with the measured waveform, the change in the impedance of the device can be grasped. And a function of calculating a difference between the two displayed voltage waveforms,
It is also possible to provide a means for issuing an alarm when the amplitude of the difference voltage waveform exceeds a preset range.

Examples of the voltage waveform and the difference waveform are shown in FIGS.
Shown in 2 shows a case where there is no change in the voltage waveform, FIG. 3 shows a case where there is a change in voltage due to a change in impedance, and FIG. 4 shows a case where there is a change in voltage and phase.

It is also possible to store a plurality of voltage waveforms and compare the stored voltage waveforms with the measured voltage waveforms for monitoring.

Then, the voltage waveforms at a plurality of portions of the plasma processing apparatus are measured, the stored waveforms are compared with the measured waveforms at each portion, and the portion where the amplitude of the difference voltage waveform is large is specified. , It is possible to identify a changed part of the device. Increasing the number of terminal arrangements makes it easier to identify a changed portion.

[0014]

As described above, according to the present invention, a change in the film formation rate / etching rate appears, and before affecting the actual work, the impedance of the conductive path is changed by applying a short confirmation power in advance. There is an advantageous effect that the detected portion can be detected and a precautionary measure can be taken.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a measured voltage waveform according to the embodiment of the present invention.

FIG. 3 is a diagram showing an example of a measured voltage waveform according to the embodiment of the present invention.

FIG. 4 is a diagram showing an example of a measured voltage waveform according to the embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum tank 5 High frequency power supply 6 Voltage measuring terminal 8 Voltage waveform measuring means 9 Voltage waveform storing means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/3065 H01L 21/302 EF term (Reference) 4G075 AA24 AA30 AA61 BC06 BD14 CA47 CA65 EB41 EC21 FC13 4K030 FA03 JA17 JA19 KA30 5F004 AA01 BA04 CB07 5F045 AA08 BB20 EH13 GB08

Claims (6)

[Claims] A step of applying high-frequency power to the plasma processing apparatus; a step of measuring a voltage waveform of a portion installed from a voltage measurement terminal installed in the plasma processing apparatus; and a step of storing the measured voltage waveform. And a step of comparing and judging the stored voltage waveform with the measured voltage waveform. 2. The method according to claim 1, wherein the step of comparing and determining the stored voltage waveform and the measured voltage waveform is performed with a plurality of stored voltage waveforms. 3. The monitoring method for a plasma processing apparatus according to claim 1, wherein a voltage waveform in an initial state of the plasma processing apparatus is stored. 4. The plasma processing apparatus according to claim 1, wherein voltage waveforms at a plurality of portions of the plasma processing apparatus are measured, a stored waveform is compared with the measured waveform at each portion, and a portion having the largest change is detected. A monitoring method for the plasma processing apparatus according to any one of the above. 5. A plasma processing method, wherein plasma processing is performed while monitoring with the plasma processing apparatus monitoring method according to claim 1. 6. A high-frequency power supply for applying high-frequency power to the plasma processing apparatus, a voltage measuring terminal installed in the plasma processing apparatus, a means for measuring a voltage waveform of a portion installed from the voltage measuring terminal, and the measurement. A plasma processing apparatus comprising: means for storing a voltage waveform; and means for comparing and judging the stored voltage waveform with a measured voltage waveform.