Auxiliary Layer Removal for Residue-Free Hybrid Bonding Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor processing, it is challenging to remove temporary polymer layers such as photoresists and temporary bonding materials without leaving residues on the surface, which can lead to micro-voids during hybrid bonding and surface corrosion.
Innovation Solution
A method is introduced where a temporary polymer layer is applied on an auxiliary layer that is removable without leaving residues, allowing for the selective removal of the polymer layer and subsequently the auxiliary layer, resulting in a residue-free surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If organic solvents or aqueous chemicals are used to strip polymer layers, then the polymer can be removed, but polymer residues remain on the surface
Solution Approach 1:
The patent introduces an auxiliary layer as an intermediary between the substrate surface and the temporary polymer layer. This auxiliary layer serves as a sacrificial interface that captures polymer residues during stripping, preventing them from contaminating the final substrate surface. The auxiliary layer is selectively removed in a final cleaning step, leaving the substrate surface residue-free.
Solution Approach 2:
The patent segments the surface protection function into two separate layers: the auxiliary layer that handles residue capture and the temporary polymer layer that provides the primary protective or bonding function. This segmentation allows each layer to be optimized independently - the auxiliary layer for easy residue release and the polymer layer for its specific application requirements.
2Quantity of substance
If stripping chemicals are applied to remove temporary bonding material, then the polymer layer is removed, but surface corrosion occurs
Solution Approach 1:
The auxiliary layer acts as a protective intermediary between the stripping chemicals and the substrate surface. It absorbs the chemical attack and residue deposition, shielding the metal and dielectric surfaces from corrosion while still allowing effective polymer removal through the auxiliary layer.
Solution Approach 2:
The auxiliary layer is designed as a sacrificial, disposable layer that is intentionally consumed during the stripping process. It is removed along with the polymer residues in the final cleaning step, eliminating the need for gentle stripping conditions that would protect the substrate but fail to remove residues effectively.
3Ease of manufacture
If polymer residues remain on the bonding surface, then the surface is easier to maintain, but micro-voids are created during hybrid bonding
Solution Approach 1:
The auxiliary layer is prepared in advance as a residue-trapping interface before the temporary polymer layer is applied. This preliminary action ensures that when stripping occurs, residues are captured by the auxiliary layer rather than contaminating the bonding surface, preventing micro-void formation in future hybrid bonding operations.
Data Source
Figure 1a~1c
Figure 2~4
Figure 5~6
AI summary
A temporary polymer layer (16) required on a substrate (1) in a semiconductor processing sequence is produced on an auxiliary layer (15) produced on the substrate prior to forming the temporary polymer layer. The auxiliary layer (15) is removable from the surface of the substrate essentially without leaving residues on said surface. The polymer layer (16) and the auxiliary layer (15) are removed after a number of processing steps performed on the substrate. The removal of the polymer layer (16) may leave residue on the auxiliary layer (15), but removing the latter leaves the surface essentially residue-free. The invention thereby enables the removal of temporary bonding material from a hybrid bonding surface without leaving polymer residue, so that the appearance of voids during hybrid bonding is avoided. The invention is however applicable also to the formation of other temporary polymer layers, such as a photoresist layer and a protective layer for singulation.