Plasma measurement method

Patent metadata

Field	Value
Publication number	US-12237157-B2
Application number	US-202217893621-A
Country	US
Kind code	B2
Filing date	Aug 23, 2022
Priority date	Sep 1, 2021
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

Measuring a plasma state using a probe device in the case of performing plasma processing on a substrate by introducing process gas into a processing container accommodating the substrate and by producing pulsed plasma using an electromagnetic wave pulse obtained by processing an electromagnetic wave generated from an electromagnetic wave oscillator using a pulsing device. An AC voltage to the pulsed plasma is applied via the probe device; transmitting a signal from the pulsed plasma based on the AC voltage via the probe device and measuring data including a current value; and obtaining a state of the pulsed plasma by analyzing the measured data. The frequency of the AC voltage deviates from a frequency of the electromagnetic wave pulse so that the number of data required for the measurement of the pulsed plasma within one cycle of the electromagnetic wave pulse is obtained within allowable time.

First claim

What is claimed is:

1. A plasma measurement method for measuring a plasma state using a probe device in the case of performing plasma processing on a substrate by introducing process gas into a processing container accommodating the substrate and by producing pulsed plasma using an electromagnetic wave pulse, wherein the electromagnetic wave pulse is obtained by processing an electromagnetic wave generated from an electromagnetic wave oscillator using a pulsing device, the method comprising:
Applying an AC voltage to the pulsed plasma using the probe device;
transmitting a signal from the pulsed plasma based on the AC voltage using the probe device and measuring data including a current value; and
obtaining a state of the pulsed plasma by analyzing the measured data;
wherein a frequency of the AC voltage is deviated from a frequency of the electromagnetic wave pulse so that the number of data required for the measurement of the pulsed plasma within one cycle of the electromagnetic wave pulse is obtained within allowable time,
wherein when the frequency of the AC voltage is f probe and the frequency of the electromagnetic wave pulse is f pulse , the conditions shown in the following Eqs. (1), (2), and (3) are satisfied:

0
≤

max
⁡
(

f

p
⁢
r
⁢
obe

,

f
pulse

)

min
⁡
(

f

p
⁢
r
⁢
obe

,

f
pulse

)

-

n
m

≤

1

max
⁡
(

f

p
⁢
r
⁢
obe

,

f
pulse

)

⁢

T
max

Eq
.

(
1
)

max
⁡
(

m
,
n

)

≥
10

Eq
.

(
2
)

max
⁡
(

m
,
n

)

max
⁡
(

f

p
⁢
r
⁢
obe

,

f
pulse

)

<

T
max

,

Eq
.

(
3
)

wherein m and n represent a set of minimum positive integers satisfying the Eq. (1), and T max represents an upper limit of the allowable time for measuring the data.

2. The plasma measurement method of claim 1 , wherein the AC voltage is continuously applied for a period of a plurality of electromagnetic wave pulses, and data of different points of the plurality of electromagnetic wave pulses are superimposed, so that the number of data within one cycle of the electromagnetic wave pulse is obtained.

3. The plasma measurement method of claim 1 , wherein T max is 10 sec or less.

4. The plasma measurement method of claim 1 , wherein the data including the current value is a current value as a two-variable function with voltage and time as variables.

5. The plasma measurement method of claim 1 , wherein the frequency of the AC voltage is within a range of 500

Assignees

• Tokyo Electron Ltd

Inventors

• Kamata Eiki
• Sato Mikio
• Ikeda Taro
• Ashida Mitsutoshi

Classifications

• H01J37/32926

  Software, data control or modelling · CPC title

• H01J37/32146 Primary

  Amplitude modulation, includes pulsing · CPC title

• H05H1/0062

  by using microwaves · CPC title

• H01J37/32935 Primary

  Monitoring and controlling tubes by information coming from the object and/or discharge · CPC title