Conductive Choke Portion for Microwave Leakage Suppression

Solution Overview

Problem

Plasma processing apparatuses using microwaves face issues with microwave leakage through components near the power feeder, leading to potential malfunctions and interference with measurement devices.

Innovation Solution

A plasma processing apparatus design incorporating a rod-shaped power feeder connected through an insulating tubular portion with a conductive choke portion, where the choke portion's second portion is approximately ¼ of the microwave wavelength in length, to attenuate or cancel the microwave propagation, and a conductive surrounding portion with an insulation member like zirconium to further suppress leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coating portion made of insulating material is used for the power feeder, then the power feeder is electrically insulated, but the microwave propagates through the coating portion causing leakage

Engineering Contradiction:

Improveelectrical insulationVSAvoidmicrowave leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The insulating tubular portion has an inner hole through which the rod-shaped power feeder extends, and the conductive surrounding portion is provided along an outer periphery of the insulating tubular portion, creating a nested configuration that addresses both insulation and microwave leakage issues simultaneously

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The conductive surrounding portion is provided along an outer periphery of the insulating tubular portion to suppress microwave propagating through the insulating tubular portion, serving as a mediator that blocks microwave leakage without compromising the insulation function

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the conductive surrounding portion is provided close to the insulating tubular portion, then microwave suppression is improved, but the risk of electrical discharge between them increases

Engineering Contradiction:

Improvemicrowave suppressionVSAvoidelectrical discharge

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The insulating tubular portion has an inner hole through which the rod-shaped power feeder extends, and the conductive surrounding portion is provided along an outer periphery of the insulating tubular portion, creating a nested configuration that addresses both insulation and microwave leakage issues simultaneously

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The insulating tubular portion is a cylindrical insulating structure that surrounds the power feeder and provides electrical insulation while allowing the conductive surrounding portion to be positioned along its outer periphery for microwave suppression

Inventive Principle:

Principle #30Flexible shells and thin films

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Effectively suppresses microwave propagation through components near the power feeder, reducing the risk of malfunctions and ensuring stable operation by minimizing microwave leakage.

Implementation Method 1

the microwave propagating through the tubular portion, i.e., a part of the incident wave, propagates through a region between the second portion of the choke portion and the power feeder and then is reflected by the first portion. The reflection wave thus generated interferes with the incident wave, so that the incident wave is attenuated or cancelled.

Methodology Applied

Scientific EffectElectromagnetic interference: Interference

Implementation Method 2

the microwave propagating through the tubular portion, i.e., a part of the incident wave, propagates through a region between the second portion of the choke portion and the power feeder and then is reflected by the first portion

Methodology Applied

Scientific EffectElectromagnetic reflection: Reflection

Implementation Method 3

an insulating tubular portion having an inner hole through which the rod-shaped power feeder extends

Methodology Applied

Scientific EffectElectrical insulation: Dielectric

Implementation Method 4

a plasma processing apparatus for exciting a processing gas by using a microwave

Methodology Applied

Scientific EffectMicrowave plasma generation: Plasma

Data Source

PatentUS9646867B2Plasma processing apparatus, power supply unit and mounting table system

Publication Date: 2017.05.09 TOKYO ELECTRON LTD

AI summary

A plasma processing apparatus includes a mounting table including a lower electrode and an electrostatic chuck, a high frequency power supply electrically connected to the lower electrode, a heater provided in the electrostatic chuck, a heater power supply for supplying a power to the heater, a filter unit including a filter connected to the heater power supply, a rod-shaped power feeder connecting the heater power supply and the heater via the filter, an insulating tubular portion having an inner hole through which the power feeder extends, and a conductive choke portion serving to suppress a microwave propagating through the tubular portion. The choke portion includes a first portion extending from the power feeder in a direction intersecting with a longitudinal direction of the power feeder and a cylindrical second portion extending, between the tubular portion and the power feeder, from a peripheral portion of the first portion.