SiC Plasma Shroud Fabrication via Partial Net Shape CVD

Solution Overview

Problem

Existing substrate processing systems face challenges in fabricating complex plasma confinement shrouds and edge rings with intricate shapes without damaging the surfaces or incurring significant material loss due to extensive machining, which can lead to reduced yield and increased risk of cracking.

Innovation Solution

A partial net shape or near net shape process is employed, where a sacrificial substrate is pre-machined into a complementary shape, and a semiconductor material like silicon carbide is deposited and machined only on non-plasma-facing surfaces, minimizing machining on plasma-facing surfaces, thereby reducing damage and material loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If extensive machining is performed to fabricate complex-shaped plasma confinement shrouds and edge rings, then the desired intricate shapes can be achieved, but surface damage increases and material loss occurs

Engineering Contradiction:

Improvecomplex shapeVSAvoidsurface quality

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The sacrificial substrate is pre-machined into the desired complex shape before deposition. This preliminary action allows the final component to inherit the precise shape from the substrate while requiring minimal post-deposition machining, thus preserving surface quality on plasma-facing surfaces.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The fabrication process is segmented into distinct phases: substrate preparation, deposition on selected surfaces, and selective machining. This segmentation allows different surfaces to be treated differently - plasma-facing surfaces are deposited without machining while non-plasma-facing surfaces undergo minimal machining as needed.

Inventive Principle:

Principle #1Segmentation

2Shape

If extensive machining is performed to achieve complex shapes, then the desired geometry can be obtained, but material loss increases reducing yield

Engineering Contradiction:

Improvecomplex shapeVSAvoidmaterial loss

Core Design Contradiction:

ShapeVSLoss of substance

Solution Approach 1:

The sacrificial substrate is pre-machined into the desired complex shape before deposition. This preliminary action allows the final component to inherit the precise shape from the substrate while requiring minimal post-deposition machining, thus preserving surface quality on plasma-facing surfaces.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sacrificial substrate is discarded after serving its purpose of providing the complex shape and supporting deposition. This approach allows the valuable semiconductor material to be deposited only where needed on the final component, minimizing material loss while achieving complex geometries.

Inventive Principle:

Principle #34Discarding and recovering

3Shape

If extensive machining is performed on plasma-facing surfaces, then complex shapes can be achieved, but the risk of cracking increases

Engineering Contradiction:

Improvecomplex shapeVSAvoidcracking risk

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The sacrificial substrate is pre-machined into the desired complex shape before deposition. This preliminary action allows the final component to inherit the precise shape from the substrate while requiring minimal post-deposition machining, thus preserving surface quality on plasma-facing surfaces.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Different surfaces are treated with different levels of machining based on their function. Plasma-facing surfaces are protected from machining to avoid cracking, while non-plasma-facing surfaces undergo minimal machining as needed. This localized quality approach optimizes reliability for critical surfaces.

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

This method reduces machining requirements, minimizes surface damage, and enhances the yield of complex-shaped plasma confinement shrouds and edge rings, allowing for more precise fabrication without extensive cutting or grinding, thus improving the overall efficiency and reliability of substrate processing systems.

Implementation Method 1

depositing a layer of material on the substrate

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS10096471B2Partial net shape and partial near net shape silicon carbide chemical vapor deposition

Publication Date: 2018.10.09 LAM RES CORP

AI summary

A method for fabricating a structure having surfaces exposed to plasma in a substrate processing system includes providing a sacrificial substrate having a first shape, machining the substrate into a second shape, the second shape having dimensions corresponding to a desired final shape of the structure, depositing a layer of material on the substrate, machining first selected portions of the layer of material to expose the substrate within the layer of material, removing remaining portions of the substrate, and machining second selected portions of the layer of material into the structure having the desired final shape without machining the surfaces of the structure that are exposed to plasma during processing.