Microwave Window Vertical Stepped Areas for Pressure Sealing

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Solution Overview

Problem

Microwave pressure windows used in semiconductor processing are prone to failure in high pressure differential environments and require costly replacement due to limited duty cycles.

Innovation Solution

A microwave transmission window apparatus comprising a dielectric plate sandwiched between two metal plates with O-rings, designed to reduce reflected power and impedance, allowing for increased duty cycles and easy serviceability by permitting replacement of the dielectric plate, O-rings, or other components without replacing the entire assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a microwave pressure window is used in high pressure differential environments, then microwaves can be transmitted into the chamber, but the pressure window is prone to failure after a given amount of pressure cycles

Engineering Contradiction:

Improvepressure cycle durabilityVSAvoidduty cycle

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The microwave pressure window is divided into separate replaceable components: a first plate, a second plate, and a dielectric plate positioned between them. This segmentation allows individual components to be replaced without replacing the entire assembly, extending the overall duty cycle and reliability of the system.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention introduces vertical step areas on the first and second plates that can be dynamically adjusted or reconfigured. These stepped areas reduce reflected power and minimize impedance during pressure cycling, allowing the system to adapt to varying pressure conditions and extend its operational life.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the microwave pressure window fails, then the entire assembly must be replaced, but this results in substantial replacement costs

Engineering Contradiction:

ImproveserviceabilityVSAvoidreplacement cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

By segmenting the pressure window into separate plates and a dielectric plate, the invention enables selective replacement of only the failed component rather than the entire assembly, significantly reducing replacement costs and improving serviceability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The design allows the dielectric plate and seals to be easily removed and replaced while retaining the metal plates, effectively discarding only the worn components and recovering the reusable structural elements, thereby reducing overall replacement costs.

Inventive Principle:

Principle #34Discarding and recovering

3Power

If vertical step areas are added to reduce reflected power and minimize impedance, then microwave transmission is improved, but the structural complexity increases

Engineering Contradiction:

Improvemicrowave transmission efficiencyVSAvoidplate structure complexity

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The vertical step areas are introduced only at specific locations on the first and second plates where they are needed to reduce reflected power and minimize impedance, rather than complicating the entire plate structure. This localized approach improves microwave transmission without excessive structural complexity.

Inventive Principle:

Principle #3Local quality

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

The solution extends the life span of microwave transmission windows, reduces manufacturing costs, and maintains vacuum integrity while transmitting high microwave power with minimal reflected power, offering a long duty cycle and easy maintenance.

Implementation Method 1

a dielectric plate configured to transmit microwaves and interposed between the first plate and the second plate

Methodology Applied

Scientific EffectDielectric transmission: Dielectric

Implementation Method 2

the first vertical step area and the second vertical step area each extends inwards into the first aperture and are configured to reduce reflected power and minimize impedance for microwaves transmitted through the apparatus

Methodology Applied

Scientific EffectImpedance matching:

Data Source

PatentUS11362404B2Microwave window including first and second plates with vertical stepped areas configured for pressure sealing a dielectric plate between the first and second plates

Publication Date: 2022.06.14 APPLIED MATERIALS INC

AI summary

Apparatus for transmitting microwaves into a process chamber using a microwave pressure window assembly. The microwave pressure window assembly may include a first plate with a first aperture surrounded by a first recess for a first pressure seal, a second plate with a second aperture surrounded by a second recess for a second pressure seal, a dielectric plate configured to transmit microwaves and interposed between the first plate and the second plate and between the first pressure seal and the second pressure seal. The apertures include a first vertical step area on a first vertical side of the apertures and a second vertical step area on a second vertical side of the apertures opposite of the first vertical side. The first vertical step areas and the second vertical step areas may have a thickness of approximately 50% of a thickness of the plates that includes a dielectric plate recess.