Donor Substrate Residue Reconditioning for Flat Bonding Surfaces
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Solution Overview
Problem
The existing methods for preparing donor substrates using Smart Cut technology face issues with bonding defects due to thermal expansion coefficient differences between the thick layer and the final support, leading to curvature and irregularities, which increase with recycling cycles, causing defects in the transferred thin layer and limiting its reuse.
Innovation Solution
A process involving grinding to remove the peripheral crown, mechanical-chemical polishing to smooth the main surface, and ionic rectification to conform the peripheral zone to a flat profile, ensuring the residue can be reused multiple times without significant quality degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the donor substrate is reused multiple times through reconditioning, then productivity increases, but manufacturing precision deteriorates due to accumulating bonding defects and surface irregularities
Solution Approach 1:
The invention applies preliminary actions by performing surface treatment (grinding, polishing, or chemical etching) and curvature correction on the donor substrate residue before it is reused. This prevents bonding defects and surface irregularities from accumulating, thereby maintaining thin layer quality across multiple substrate reuse cycles and resolving the contradiction between productivity and manufacturing precision.
2Ease of manufacture
If the peripheral crown is eliminated through aggressive removal methods, then ease of manufacture improves, but manufacturing precision deteriorates due to damage to the main surface
Solution Approach 1:
The invention applies local quality by using selective removal methods that target only the peripheral crown region while preserving the main surface. Grinding, polishing, or chemical etching is applied locally to the peripheral zone with controlled parameters, eliminating the crown without damaging the central area that will be used for subsequent bonding and thin layer transfer, thus resolving the contradiction between ease of manufacture and manufacturing precision.
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 process effectively reduces bonding defects and allows for the reuse of donor substrates multiple times, maintaining the quality of the transferred thin layer by ensuring a flat and smooth surface for molecular adhesion, thereby extending the substrate's lifespan.
Implementation Method 1
the donor substrate is brought into contact with the final support at the apex of the convexity... A bonding wave is then initiated tending to bring the two surfaces facing each other into contact
Data Source
Figure 1a~2b
Figure 2c~3D
AI summary
The invention relates to a method for preparing the residue (1') of a donor substrate, the residue (1') comprising, on a peripheral zone (13) of a main face (10), a peripheral ring. The method comprises: a first step of removing at least one portion of the peripheral ring; a second step of treating the main face (10) of the residue (1') aiming to remove a surface layer; a third step, after the second step, of grinding the peripheral zone (13) of the main face (10) of the residue (1'), the grinding third step aiming to reduce the height of the peripheral zone (13).