Stepped Electrostatic Chuck for Backside Plasma Processing

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Solution Overview

Problem

Existing substrate processing methods face challenges in effectively performing plasma processing on the lower surface of a substrate while minimizing stress and preventing particle generation during post-processing, particularly in back side deposition techniques.

Innovation Solution

A substrate processing apparatus is designed with a chamber, an upper cover, an electrostatic chuck, and a plasma unit that generates plasma below the upper cover and electrostatic chuck, utilizing a parallel plate structure to perform plasma processing on the lower surface of the substrate, preventing contact with the upper cover and thus avoiding film formation on the upper surface, and using an electrostatic chuck to retain the substrate and control the plasma processing area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plasma processing is performed on the lower surface of the substrate using a conventional setup, then plasma processing can be achieved, but the substrate may contact the upper cover causing film formation on the upper surface and particle generation

Engineering Contradiction:

Improveplasma processing effectivenessVSAvoidfilm formation on upper surface and particle generation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The electrostatic chuck is designed with a stepped structure featuring a first upper surface and a second upper surface at a different height. This dimensional change creates a multi-level platform that enables plasma processing on the lower surface while preventing substrate contact with the upper cover, thereby avoiding film formation and particle generation on the upper surface.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The electrostatic chuck provides different surface heights at different locations: the first upper surface is positioned at one height for plasma processing, while the second upper surface is positioned at a different height to prevent contact with the upper cover. This local quality differentiation resolves the contradiction between enabling plasma processing and preventing harmful film formation.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If the substrate is retained using a simple electrostatic chuck structure, then substrate retention is achieved, but precise control over plasma processing area is difficult

Engineering Contradiction:

Improvesubstrate retentionVSAvoidplasma processing area control

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The electrostatic chuck is segmented into distinct surfaces at different heights: a first upper surface for plasma processing and a second upper surface for preventing contact. This segmentation allows independent control of plasma processing area while maintaining substrate retention, resolving the contradiction between ease of operation and manufacturing precision.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If deposition is performed on the front surface only, then the process is simple, but stress is introduced causing wafer warpage

Engineering Contradiction:

Improvedeposition process simplicityVSAvoidwafer stress and warpage

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The stepped electrostatic chuck enables deposition on both the front surface and back surface of the wafer by providing different height levels. This dimensional configuration allows stress compensation through back surface deposition while maintaining process simplicity, resolving the contradiction between device complexity and stability.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 solution enables efficient plasma processing on the lower surface of the substrate, reducing stress and particle generation, while effectively preventing film formation on the upper surface, thereby alleviating warpage and ensuring precise control over the plasma processing area.

Implementation Method 1

an electrostatic chuck which includes an annular portion of a dielectric body and an embedded electrode embedded into the annular portion

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

a plasma unit configured to generate plasma in a region below the upper cover and the electrostatic chuck

Methodology Applied

Scientific EffectPlasma generation: Plasma

Data Source

PatentUS11929251B2Substrate processing apparatus having electrostatic chuck and substrate processing method

Publication Date: 2024.03.12 ASM IP HLDG BV

AI summary

Examples of a substrate processing apparatus includes a chamber, an upper cover provided inside the chamber, an electrostatic chuck which includes an annular portion of a dielectric body and an embedded electrode embedded into the annular portion, the electrostatic chuck being provided inside the chamber, and a plasma unit configured to generate plasma in a region below the upper cover and the electrostatic chuck, wherein the annular portion includes an annular first upper surface located immediately below the upper cover, and a second upper surface located immediately below the upper cover and surrounding the first upper surface, the second upper surface having a height higher than a height of the first upper surface.