Method of determining correction function

Patent metadata

Field	Value
Publication number	US-11249126-B2
Application number	US-202016848483-A
Country	US
Kind code	B2
Filing date	Apr 14, 2020
Priority date	Apr 23, 2019
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A method includes measuring first travelling wave power of a microwave having a single frequency peak and second travelling wave power having a single frequency peak, acquiring duty ratios of the first travelling wave power and the second travelling wave power based on measured values and a first determination threshold value, measuring third travelling wave power of a microwave having a bandwidth and fourth travelling wave power having a bandwidth, acquiring duty ratios of the third travelling wave power and the fourth travelling wave power based on measured values and a second determination threshold value, approximating a pulse width error between the first travelling wave power and the third travelling wave power and a pulse width error between the second travelling wave power and the fourth travelling wave power with linear functions, and determining the correction function based on the linear functions.

First claim

What is claimed is:

1. A method of determining a correction function for correcting a measurement result from a wave detector detecting a microwave which is pulse-modulated such that power of the microwave is turned on and off, the method comprising:
measuring first travelling wave power of a microwave of which power is pulse-modulated such that an ON level corresponds to first setting power and which has a single frequency peak and second travelling wave power of a microwave of which power is pulse-modulated such that an ON level corresponds to second setting power and which has a single frequency peak, by using a calibration measuring device;
acquiring a duty ratio of the first travelling wave power and a duty ratio of the second travelling wave power on the basis of measured values in the measuring by using the calibration measuring device and a first determination threshold value for determining an ON level of power;
measuring third travelling wave power of a microwave of which power is pulse-modulated such that an ON level corresponds to the first setting power and which has a center frequency and a bandwidth and fourth travelling wave power of a microwave of which power is pulse-modulated such that an ON level corresponds to the second setting power and which has a center frequency and a bandwidth, by using the wave detector;
acquiring a duty ratio of the third travelling wave power and a duty ratio of the fourth travelling wave power on the basis of measured values in the measuring by using the wave detector and a second determination threshold value, set in advance in a range more than 0% of the setting power and less than 50% of the setting power, for determining an ON level of power;
approximating a pulse width error between the first travelling wave power and the third travelling wave power corresponding to the first setting power and a pulse width error between the second travelling wave power and the fourth travelling wave power corresponding to the second setting power with linear functions by setting, as coordinate axes, the setting power, and a pulse width error which is an error between a pulse width based on a duty ratio obtained by using a measured value in the calibration measuring device and a pulse width based on a duty ratio obtained by using a measured value in the wave detector; and
determining the correction function on the basis of the linear functions.

2. The method of determining a correction function according to claim 1 , wherein the first setting power and the second setting power are equal to or more than 1000 W.

Assignees

• Tokyo Electron Ltd

Inventors

• Kaneko Kazushi
• Ishida Yohei

Classifications

• G01R29/023 Primary

  Measuring pulse width · CPC title

• G01R21/01 Primary

  in circuits having distributed constants (G01R21/04, G01R21/07, G01R21/09, G01R21/12 take precedence) · CPC title

• G01R35/005

  Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R33/0035, G01R35/002 take precedence) · CPC title

• H01J37/32311 Primary

  Circuits specially adapted for controlling the microwave discharge · CPC title

• H03K3/017

  Adjustment of width or dutycycle of pulses (pulse width modulation H03K7/08 {; to maintain energy constant H03K3/015}) · CPC title