Substrate Holder Shielding Part Corner Discontinuity

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Solution Overview

Problem

The challenge is to improve the in-plane uniformity of a rectangular substrate during the electrolytic plating process, as shielding the electric field over the entire periphery can lead to reduced film thickness and non-uniformity, especially at the corners, due to excessive shielding.

Innovation Solution

A substrate holder with a frame-shaped shielding part and discontinuous corners is used, along with a regulation plate having corner masks, to adjust the electric field and prevent over-shielding, ensuring uniform film thickness across the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a frame-shaped shielding part with uniform shielding width is used, then the terminal effect is suppressed, but the corner regions experience excessive shielding from overlapping electric field shielding of two adjacent sides

Engineering Contradiction:

Improveterminal effect suppressionVSAvoidcorner film thickness

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The shielding part transitions from a uniform frame shape to a differentiated frame shape where corner portions have reduced shielding width. This allows the side portions to maintain effective terminal effect suppression while corner portions with smaller shielding width avoid the overlapping shielding problem, ensuring adequate film thickness at corners.

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 configuration enhances the in-plane uniformity of the substrate by attenuating excessive electric field shielding at the corners, resulting in a more uniform film thickness and improved plating results.

Implementation Method 1

a shielding part which protrudes closer to an inner side than the opening and shields the peripheral part of a surface of the substrate

Methodology Applied

Scientific EffectElectric field shielding: Electric Field

Implementation Method 2

the shielding part has, at a corner part of the shielding part, a discontinuous part which has a smaller shielding width than surroundings

Methodology Applied

Scientific EffectElectric field control: Electric Field

Implementation Method 3

the substrate is clamped between the first holding member and the second holding member

Methodology Applied

Scientific EffectMechanical clamping: Mechanical Force

Implementation Method 4

a contact which contacts a peripheral part of the substrate and supplies an electric current to the substrate

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11280020B2Substrate holder and plating device

Publication Date: 2022.03.22 EBARA CORP

AI summary

According to an embodiment, a substrate holder holds a rectangular substrate and performs electrolytic plating on the substrate. The substrate holder includes a first holding member and a second holding member clamping the substrate between the first holding member and it and having a contact which contacts a peripheral part of the substrate and supplies an electric current to the substrate. The second holding member includes an opening defining a region where an electric field is formed and, at a position farther from the substrate than the opening, a shielding part protruding closer to an inner side than the opening and shielding the peripheral part of a surface of the substrate. The shielding part has a frame shape having a predetermined shielding width in the peripheral part of the substrate, and has, at a corner part thereof, a discontinuous part having a smaller shielding width than surroundings.