Bonded Substrate Groove Formation via Water Jet Guided Laser
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Solution Overview
Problem
Existing methods for manufacturing bonded substrates, such as SOI substrates, face issues with breakage, cracks, particle generation, and irregularities during film thickness reduction due to unbonded portions, which complicate processes and reduce yield.
Innovation Solution
A method involving the creation of a groove on the active layer wafer using a water jet guided laser along the outer peripheral portion, allowing for precise bonding and subsequent film thickness reduction without grinding, thereby simplifying processes and ensuring excellent edge shape management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional grinding methods are used to reduce film thickness, then film thickness can be reduced, but unbonded portions cause delamination and particle generation
Solution Approach 1:
The groove is formed on the active layer wafer before bonding to the support substrate wafer. This preliminary action defines the bonding area and prevents unbonded portions from forming in the first place, eliminating the source of delamination and particle generation during subsequent film thickness reduction processes
Solution Approach 2:
The wafer surface is segmented into a bonding area (inside the groove) and a non-bonding area (outside the groove) by forming a groove structure. This segmentation ensures that only the intended area bonds to the support substrate, preventing peripheral unbonded portions that cause delamination
2Reliability
If additional etching steps are added to remove unbonded portions, then delamination can be prevented, but process complexity increases
Solution Approach 1:
The groove is formed in advance before bonding, preliminarily defining the bonding perimeter. This preliminary action eliminates the need for subsequent etching steps to remove unbonded portions, as the groove structure itself prevents unbonded portion formation from the outset
Solution Approach 2:
The problematic unbonded portions are extracted from the system by forming a groove that prevents their formation. Instead of adding steps to remove them after bonding, the groove structure extracts the issue at the design stage, simplifying the overall process
3Manufacturing precision
If water jet guided laser is used to form groove, then edge shape precision is improved, but equipment complexity increases
Solution Approach 1:
The conventional mechanical groove formation methods (such as mechanical machining or abrasion) are replaced with a water jet guided laser system. This substitution provides superior edge shape precision and groove quality while enabling precise control of the groove geometry through laser guidance
Solution Approach 2:
A water jet is utilized as the machining medium instead of conventional mechanical cutting tools. The high-pressure water jet, guided by laser positioning, achieves precise groove formation with excellent edge quality, combining hydraulic power with optical guidance for superior 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
This approach eliminates the need for additional etching steps, reduces particle generation, and ensures a high-quality bonded substrate with a consistent diameter and excellent edge shape, enhancing manufacturing efficiency and yield.
Implementation Method 1
the groove provided on the inner side on the surface of the active layer wafer along the outer peripheral portion is machined by using a water jet guided laser
Data Source
Figure 1(a)~1(f)
Figure 2
Figure 3(a)~3(g)
AI summary
The present invention provides a method for manufacturing a bonded substrate that is a method for manufacturing a bonded substrate where an active layer wafer is bonded to a support substrate wafer, comprising: a first step of providing a groove on an inner side on a surface of the active layer wafer along an outer peripheral portion over an entire circumference; a second step of determining a surface where the groove is formed as a bonding surface and bonding the active layer wafer to the support substrate wafer; and a third step of reducing a film thickness of the active layer wafer and removing an unbonded portion on an outer side of the groove of the active layer wafer. As a result, there is provided the method for manufacturing a bonded substrate that can simplify processes, avoid breakage, cracks, or particle generation, and manage a shape of an edge portion of an active layer wafer when reducing a film thickness of the active layer wafer.