Roughened Substrate Support for Flat Panel Display ESD Reduction

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Solution Overview

Problem

Large area substrate processing in flat panel display fabrication faces issues such as film thickness variations, electro-static discharge (ESD) metal line arcing, and particle attraction due to static charge, which are exacerbated by the size and properties of the substrates, leading to defects and increased costs in semiconductor processing.

Innovation Solution

A substrate support with an electrically conductive body and an electrically insulative coating having a surface finish between 200 to 2000 micro-inches, which reduces capacitance variations and charge transfer, thereby enhancing deposition uniformity and minimizing arcing and particle attraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a smooth substrate support surface (about 50 micro-inches) is used, then good processing performance is achieved, but local capacitance variations occur creating plasma non-uniformities and film thickness spots

Engineering Contradiction:

Improveprocessing performanceVSAvoidfilm thickness uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The substrate support surface is modified to have non-uniform roughness characteristics - specifically engineered to reduce capacitance variations in certain locations across the glass substrate. This localized surface modification creates more uniform electrical properties across the support surface, eliminating plasma non-uniformities and resulting in uniform film thickness deposition without requiring time-consuming aging processes.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If substrate support aging and extended vacuum purge are performed, then thin spot formation is mitigated, but time and material expenditures increase reducing throughput and increasing cost

Engineering Contradiction:

Improvefilm thickness uniformityVSAvoidsystem throughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The substrate support surface is pre-modified with controlled roughness characteristics before substrate processing begins. This preliminary surface engineering eliminates the need for time-consuming aging processes and extended vacuum purges that were previously required to achieve uniform film deposition. The pre-configured surface properties ensure consistent plasma distribution and uniform film thickness from the first substrate processed, significantly improving system throughput while maintaining manufacturing precision.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If large area substrates are processed, then production capacity increases, but electro-static discharge arcing and particle attraction defects increase

Engineering Contradiction:

Improveproduction capacityVSAvoidarcing and particle attraction

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The electrical properties of the substrate support surface are modified through controlled roughness engineering. This parameter change reduces electro-static charge accumulation and minimizes charge transfer between the substrate and support during processing. The modified surface characteristics prevent electro-static discharge arcing and reduce particle attraction defects, enabling reliable processing of large area substrates without the defects that would otherwise limit production capacity.

Inventive Principle:

Principle #35Parameter changes

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 improves film thickness uniformity, reduces the occurrence of arcing and particle attraction, and decreases the need for costly aging processes, resulting in increased system throughput and reduced costs.

Implementation Method 1

creates a local capacitance variation in certain locations across the glass substrate, thereby creating local plasma non-uniformities

Methodology Applied

Scientific EffectCapacitance variation: Capacitance

Implementation Method 2

reduces capacitance variations and charge transfer, thereby enhancing deposition uniformity and minimizing arcing and particle attraction

Methodology Applied

Scientific EffectElectrostatic charge: Electrostatics

Data Source

PatentUS8372205B2Reducing electrostatic charge by roughening the susceptor

Publication Date: 2013.02.12 APPLIED MATERIALS INC

AI summary

A substrate support and method for fabricating the same are provided. In one embodiment of the invention, a substrate support includes an electrically conductive body having a substrate support surface that is covered by an electrically insulative coating. At least a portion of the coating centered on the substrate support surface has a surface finish of between about 200 to about 2000 micro-inches. In another embodiment, a substrate support includes an anodized aluminum body having a surface finish on the portion of the body adapted to support a substrate thereon of between about 200 to about 2000 micro-inches. In one embodiment, a substrate support assembly includes an electrically conductive body having a substrate support surface, a substrate support structure that is adapted to support the conductive body and the conductive body is covered by an electrically insulative coating.