Stacked Wafer Edge Structure for Better Coating Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable devices at smaller sizes due to the complexity of processing and manufacturing ICs, where coating materials adhere poorly to steep wafer edges, leading to defects and contamination.
Innovation Solution
A multi-trimming process is applied to the underlying wafer to create a stepped sidewall structure, improving adhesion of coating materials and minimizing contamination, thereby enhancing production efficiency and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a steep wafer edge structure is used, then the wafer can be processed with standard equipment, but coating materials adhere poorly leading to defects and contamination
Solution Approach 1:
The wafer edge is segmented into multiple levels through the multi-trimming process, creating a stepped structure with first, second, and third levels. This segmentation transforms the single steep edge into multiple gentler slopes, allowing coating materials to adhere properly at each level while maintaining the overall edge structure needed for standard equipment processing.
Solution Approach 2:
The invention applies local quality modification by creating different geometric configurations at different portions of the wafer edge. The stepped structure provides varying surface angles and areas at different levels, with each level optimized for specific functions: the first level maintains equipment compatibility, while the second and third levels provide enhanced coating adhesion surfaces.
2Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency increases and costs decrease, but processing complexity and manufacturing difficulty increase
Solution Approach 1:
The multi-trimming process is performed as a preliminary action before coating operations. By pre-forming the stepped wafer edge structure with controlled levels and surfaces, the subsequent coating process can proceed smoothly without the complexity of dealing with steep edges, thereby maintaining high production efficiency while reducing processing difficulties.
Data Source
AI summary
A method includes bonding a front side surface of a first wafer to a front side of a second wafer; forming a bonding material on a periphery of the first wafer and a periphery of the second wafer; performing a thinning process on the first wafer from a back side surface of the first wafer; after performing the thinning process, performing a trimming process from the back side surface of the first wafer to remove a first portion of the bonding material and partially trim down the periphery of the second wafer from a front side surface of the second wafer.