GaN Wafer Division via Offset Cutting Start Point
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Solution Overview
Problem
The misalignment of cutting start points during the division of GaN-based semiconductor wafers on sapphire substrates leads to poor appearance and reduced output of light emitting elements due to oblique breaking, which affects the mechanical strength and active layer damage, and the prior methods fail to consider the relationship between cutting positions and N-electrodes.
Innovation Solution
A light emitting element manufacturing method that involves dividing the semiconductor wafer with a narrower horizontal dividing region parallel to the A-plane and a vertical dividing region perpendicular to it, with N-electrodes disposed on both sides of the vertical dividing region, and shifting the cutting start point from the center line to reduce damage and increase the number of obtainable elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the width of the dividing region is narrowed to increase the number of light emitting elements, then the productivity is improved, but the mechanical strength deteriorates due to misalignment between cutting start point and cut position
Solution Approach 1:
The invention performs preliminary action by pre-calculating and pre-positioning the cutting start point offset from the center line of the dividing region, taking into account the misalignment that occurs during the cutting process. This preliminary positioning ensures that even with misalignment, the cut position remains at a safe distance from the light emitting element, thereby maintaining mechanical strength while enabling narrower dividing regions for higher productivity.
2Strength
If the cutting start point is offset to account for misalignment, then the mechanical strength is improved, but the relationship with N-electrode position is not considered leading to potential damage
Solution Approach 1:
The invention applies local quality by making the N-electrode width asymmetric with respect to the dividing region. Specifically, the N-electrode is designed to extend further toward one dividing region than the other, creating a buffer zone that provides different safety margins on each side. This asymmetric design ensures that even with cutting misalignment, the active layer is protected from damage while maintaining proper electrical connection.
3Productivity
If the horizontal dividing region width is minimized to increase element count, then the productivity is improved, but the appearance quality deteriorates due to cut proximity to light emitting element
Solution Approach 1:
The invention performs preliminary action by pre-calculating the optimal cutting start point position that compensates for misalignment and ensures adequate clearance from the light emitting element. By positioning the cutting start point offset from the center line and considering the N-electrode asymmetric extension, the invention ensures that the final cut position maintains proper spacing, thereby preserving appearance quality even with minimized dividing region width for higher productivity.
Data Source
AI summary
A light emitting element manufacturing method includes a wafer preparing process of preparing the semiconductor wafer, and a wafer dividing process of dividing the semiconductor wafer. In the wafer dividing process, in a vertical dividing region, a line position shifted by a predetermined distance from a center line of the vertical dividing region in a width direction to one side in the width direction is taken as the cutting start point to divide the semiconductor wafer.