Wafer Chuck Vacuum Barrier Protrusions
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Solution Overview
Problem
Wafer chucks fail to precisely adsorb wafers under vacuum pressure, leading to slipping, bending, and warping during semiconductor chip manufacturing, and also contaminate the wafer's back surface.
Innovation Solution
A wafer chuck design featuring a body portion with a vacuum barrier structure, protrusions, and strategically arranged vacuum holes to enhance chucking force and minimize contact area, reducing contamination and preventing slipping, bending, and warping by distributing stress evenly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum pressure is applied to adsorb the wafer, then the wafer can be held on the chuck, but the wafer may slip, bend, or warp due to insufficient adsorption precision
Solution Approach 1:
The chuck surface is segmented into multiple protrusions distributed across the vacuum barrier portion, creating multiple discrete adsorption points. This segmentation allows precise localization of the wafer through coordinated vacuum action at multiple points, preventing slipping and positioning the wafer accurately at the center.
Solution Approach 2:
The vacuum barrier portion is positioned at a specific distance from the center point, creating a localized vacuum zone with optimized pressure distribution. The protrusions are strategically arranged within this zone to provide enhanced local adsorption force where needed, ensuring precise wafer positioning and preventing warping.
2Force
If the wafer chuck contacts the back side of the wafer to provide chucking force, then slipping is prevented, but contamination of the wafer back surface occurs
Solution Approach 1:
The harmful contact between the chuck body and the wafer back surface is extracted and replaced by a non-contact vacuum field. The vacuum barrier portion creates a vacuum zone that adsorbs the wafer without physical contact, eliminating contamination while maintaining sufficient chucking force through the protrusions.
Solution Approach 2:
A vacuum field is introduced as the primary mechanism for holding the wafer. The vacuum holes penetrate the body portion to create negative pressure that adsorbs the wafer on the protrusions, providing chucking force without mechanical contact and thus preventing contamination of the wafer back surface.
3Force
If vacuum holes are positioned to maximize adsorption, then chucking force is strengthened, but stress distribution becomes uneven causing wafer warping
Solution Approach 1:
The vacuum holes are asymmetrically positioned with one hole at the center portion and another at the inner peripheral portion of the vacuum barrier. This asymmetric arrangement creates a optimized stress distribution pattern that maintains wafer flatness while providing sufficient chucking force, preventing warping.
Solution Approach 2:
The vacuum barrier portion is arranged at the same distance from the center point, creating a uniform vacuum field distribution. This equipotential arrangement ensures even stress distribution across the wafer surface, preventing warping while maintaining effective chucking force through the protrusions.
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 design effectively suppresses wafer slipping, bending, and warping while minimizing contamination of the wafer's back surface by strengthening the chucking force and optimizing vacuum pressure distribution.
Implementation Method 1
The wafer chuck may adsorb the wafer seated on the wafer chuck under vacuum pressure
Implementation Method 2
protrusions inside and outside the vacuum barrier portion, protruding from a top surface of the body portion
Data Source
AI summary
A wafer chuck includes a body portion; a vacuum barrier portion including a wall structure arranged at the same distance from a center point of the body portion; f protrusions arranged inside and outside the vacuum barrier portion, protruding from a top surface of the body portion and spaced apart from each other; and a vacuum portion including vacuum holes spaced apart from each other penetrating the body portion inside the vacuum barrier portion.