Combined Substrate Edge Trimming with Laser-Formed Non-Bonding Regions
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Solution Overview
Problem
Conventional edge trimming methods for semiconductor wafers often result in incomplete removal of peripheral portions, leading to flaws or apparatus breakdowns due to the formation of sharp knife-edge shapes and inadequate peeling, which complicates the thinning process of combined substrates.
Innovation Solution
A substrate processing method involving the formation of a peripheral modification layer and a non-bonding region to reduce bonding strength, allowing for controlled crack development and stable peeling of the peripheral portion, using laser modification to create a non-bonding region and peripheral modification layers that facilitate appropriate removal of the peripheral portion during edge trimming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional edge trimming methods are used to remove the peripheral portion of the wafer, then the peripheral portion can be removed, but incomplete removal occurs leading to knife-edge shapes and chipping
Solution Approach 1:
The method forms a peripheral modification layer and a non-bonding region before the actual removal process. The peripheral modification layer is created by laser irradiation to weaken the structure, and the non-bonding region is formed by reducing bonding strength between substrates in the peripheral area. These preliminary modifications enable complete and clean removal without knife-edge shapes or chipping.
Solution Approach 2:
The invention applies different treatments to different regions: the peripheral modification layer is formed only in the peripheral portion to be removed, while the non-bonding region is created specifically at the bonding interface in the peripheral area. This localized modification ensures that only the intended peripheral portion is affected, maintaining precision and preventing damage to the central portion.
2Ease of manufacture
If the peripheral portion is removed from combined substrates, then edge trimming is achieved, but inadequate peeling occurs causing apparatus breakdown
Solution Approach 1:
Before removing the peripheral portion, the method preliminarily forms a non-bonding region by laser irradiation to reduce bonding strength between the first and second substrates in the peripheral area. This preliminary action ensures that when the peripheral portion is removed, clean peeling occurs without inadequate separation that could damage the apparatus.
Solution Approach 2:
The invention changes the bonding strength parameter in the peripheral region by using laser irradiation to create a non-bonding region. This parameter change reduces the bonding strength from its original strong state to a weakened state, enabling easy and complete peeling of the peripheral portion without damaging the apparatus.
3Manufacturing precision
If laser modification is used to form peripheral modification layer and non-bonding region, then stable and complete removal is achieved, but process complexity increases
Solution Approach 1:
The method combines the formation of the peripheral modification layer and the non-bonding region into a single integrated process using laser irradiation. By merging these two modifications into one step, the process achieves stable and complete removal while minimizing the increase in process complexity.
Solution Approach 2:
The invention replaces complex mechanical removal methods with laser-based modification. Instead of using mechanical tools that may cause knife-edge shapes and chipping, the method uses laser irradiation to create the peripheral modification layer and non-bonding region, achieving cleaner and more stable removal with reduced mechanical complexity.
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
Enables stable and complete removal of the peripheral portion, preventing chipping and damage to the wafer and processing apparatus, ensuring a smooth thinning process and improved quality of the semiconductor substrate.
Implementation Method 1
radiating a laser beam along an edge of the wafer
Implementation Method 2
forming a peripheral modification layer along a boundary between a peripheral portion of the first substrate as a removing target
Data Source
AI summary
A substrate processing method of processing a combined substrate in which a first substrate and a second substrate are bonded to each other includes forming a peripheral modification layer along a boundary between a peripheral portion of the first substrate as a removing target and a central portion of the first substrate; forming a non-bonding region in which bonding strength between the first substrate and the second substrate in the peripheral portion is reduced; and removing the peripheral portion starting from the peripheral modification layer. A first crack is developed from the peripheral modification layer toward the second substrate. The peripheral modification layer is formed such that a lower end of the first crack is located above the non-bonding region and an inner end of the non-bonding region is located at a diametrically outer side than the first crack.