Wafer Bonding Apparatus with Segmented Vacuum Mounting
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving precise alignment and avoiding contamination during the bonding of thin, polished wafers, particularly due to increased adhesion and topography, which complicates detachment and leads to alignment inaccuracies and scrap.
Innovation Solution
The solution involves pretensioning at least one substrate radially to influence the contact-making process, using deformation means to control the bonding, reducing the active mounting surface, and employing a geometrical arrangement with negative pressure channels and adjustable ring sections to facilitate controlled attachment and detachment with minimal force and distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the contact surface area between wafer and mounting apparatus is reduced to minimize adhesion, then ease of detachment is improved, but mounting stability deteriorates
Solution Approach 1:
The mounting surface is segmented into two distinct zones: a large peripheral mounting contour area for stable vacuum fixation, and a small central active mounting surface for minimal adhesion during detachment. This spatial segmentation allows the wafer to be firmly held at the edges while maintaining easy release from the center bonding area.
Solution Approach 2:
Different regions of the mounting apparatus are assigned different functional qualities: the peripheral mounting contour provides strong adhesion through vacuum pressure for stability, while the central active mounting surface provides minimal adhesion for easy detachment. This local differentiation of adhesive properties resolves the contradiction between stable mounting and easy release.
2Reliability
If vacuum pressure is increased to improve wafer fixation, then mounting stability is improved, but detachment force required increases
Solution Approach 1:
The vacuum pressure is applied selectively to different zones: high vacuum pressure acts on the peripheral mounting contour to ensure stable fixation, while the central active mounting surface experiences minimal or no vacuum pressure, allowing easy detachment without requiring high detachment forces.
Solution Approach 2:
The vacuum pressure distribution is made non-uniform: strong vacuum pressure at the periphery for stable fixation, and weak or zero vacuum pressure at the center for easy detachment. This local differentiation of pressure conditions resolves the contradiction between strong fixation and low detachment force.
3Manufacturing precision
If alignment precision is increased to below 250 nm, then bonding quality is improved, but susceptibility to contamination and faults increases
Solution Approach 1:
The wafer surfaces undergo preliminary hydrophilization treatment and are maintained in a controlled environment before bonding. The mounting apparatus maintains precise positioning and cleanliness protocols in advance, reducing the risk of contamination during the high-precision alignment and bonding process.
Solution Approach 2:
A controlled atmosphere or protective environment acts as an intermediary between the precision alignment system and external contamination sources. This protective medium allows high-precision alignment to be maintained while shielding the substrates from dust and contaminants that could compromise bonding 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 achieves high alignment accuracy with minimal distortion and contamination, enabling reliable and precise bonding of substrates while allowing for easy detachment, thus reducing scrap and maintaining cleanliness.
Implementation Method 1
fixing taking place by applying a vacuum between the wafer and the mounting apparatus
Implementation Method 2
The pretensioning is achieved by a deformation of the first substrate by deformation means
Implementation Method 3
The prebonds between the molecule-wetted substrates arise mainly due to the van-der-Waals interactions between the molecules of the different sides of the wafers
Data Source
AI summary
This invention relates to a method and a device for temporary bonding of a first substrate with a second substrate. The device is comprised of a mounting apparatus for mounting of the first substrate on a mounting contour with an active mounting surface. The mounting apparatus has an outer ring section for controllable fixing of the first substrate. Deformation means are provided for controllable deformation of the first substrate. The deformation means act within the outer ring section. Bonding means are provided for bonding of the first substrate with the second substrate.