Bonded Wafer Edge Trimming to Remove Stress-Damaged Regions
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Solution Overview
Problem
The semiconductor wafers are prone to breakage during transportation and subsequent processes due to residual stress in the damaged regions formed after edge trimming.
Innovation Solution
A manufacturing method that includes forming a photoresist layer to mask and remove the damaged regions, followed by etching processes to expose clean surfaces, and applying a dielectric layer to stabilize the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an edge trimming process is performed on the wafer, then breakage prevention during bonding is improved, but damaged regions with residual stress are formed causing subsequent breakage
Solution Approach 1:
The damaged region is selectively removed from the wafer substrate through etching processes. The photoresist layer serves as a mask to define the removal area, extracting only the harmful damaged portion while preserving the healthy substrate material, thereby eliminating the source of residual stress without compromising the bonded structure
Solution Approach 2:
The photoresist layer is formed on the wafer surface before the etching process to predefine the area that needs to be removed. This preliminary masking action prepares the wafer for selective damaged region removal, ensuring that only the appropriate areas are etched while protecting the rest of the structure
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
Effectively prevents wafer breakage during transportation and subsequent processes by removing the damaged regions and stabilizing the structure.
Implementation Method 1
A first photoresist layer is formed. The first photoresist layer is located on the second wafer and the second upper surface and exposes the first upper surface and the damaged region
Implementation Method 2
The damaged region is removed by using the first photoresist layer as a mask. The method of removing the damaged region may include performing an etching process on the damaged region
Data Source
AI summary
A manufacturing method of a semiconductor structure includes the following steps. A first wafer is provided. The first wafer includes a first substrate and a first device layer. A second wafer is provided. The second wafer includes a second substrate and a second device layer. The second device layer is bonded to the first device layer. An edge trimming process is performed on the first wafer and the second wafer to expose a first upper surface of the first substrate and a second upper surface of the first substrate and to form a damaged region in the first substrate below the first upper surface and the second upper surface. The second upper surface is higher than the first upper surface. A first photoresist layer is formed. The first photoresist layer is located on the second wafer and the second upper surface and exposes the first upper surface and the damaged region. The damaged region is removed by using the first photoresist layer as a mask. The first photoresist layer is removed.