Nitride Semiconductor Wafer Laser Dicing Damage Reduction
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Solution Overview
Problem
The existing methods for manufacturing nitride semiconductor elements using laser dicing technology often result in damage to the nitride semiconductor layer due to laser beam irradiation, leading to issues like leakage, low-voltage breakdown, and reduced yield, especially as the wafer thickness increases.
Innovation Solution
A method involving the preparation of a wafer with a nitride semiconductor layer containing p-type dopants, where a laser beam is focused to form an altered portion, followed by annealing to reduce damage and enhance the p-type nitride semiconductor layer formation, thereby minimizing laser-induced damage during the dicing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser beam output is increased to divide thicker wafers, then dividing capability is improved, but damage to the nitride semiconductor layer increases
Solution Approach 1:
The patent applies preliminary action by forming the altered portion (division starting point) in the substrate before applying external force for wafer division. This pre-formed altered portion serves as a controlled initiation point that reduces the need for high laser output during the division process, thereby preventing damage to the nitride semiconductor layer while maintaining the ability to divide thicker wafers.
2Object-affected harmful factors
If laser beam irradiation is reduced to minimize damage, then semiconductor layer damage is reduced, but yield decreases due to undivided portions
Solution Approach 1:
The patent forms the altered portion as a division starting point before the actual division process. This preliminary formation ensures that when external force is applied, the wafer will reliably divide along the predetermined path through the altered portion, eliminating undivided portions and ensuring high yield without requiring excessive laser irradiation that would damage the semiconductor layer.
3Productivity
If high laser output is used to ensure complete division, then dividing efficiency is improved, but the number of irradiation increases causing more damage
Solution Approach 1:
The patent pre-forms the altered portion in the substrate at the exact location where division is needed. This preliminary action creates a focused, localized modification that requires minimal subsequent laser irradiation (or no additional irradiation) to complete the division, thereby maintaining high dividing efficiency while minimizing the total number of laser irradiations and preventing cumulative damage to the nitride semiconductor layer.
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 effectively reduces damage to the nitride semiconductor layer, improving the yield and output power of nitride semiconductor elements by allowing for more precise control over the laser scribing process and reducing the risk of undivided portions and ununiform shapes during wafer division.
Implementation Method 1
a laser beam is focused on a surface or an inner portion of an objective material (for example, a wafer) to form an altered portion which is to serve as a division starting point
Implementation Method 2
forming a p-type nitride semiconductor layer by subjecting the wafer to annealing
Data Source
AI summary
A method of manufacturing a nitride semiconductor element includes preparing a wafer having a nitride semiconductor layer which includes p-type dopants, forming an altered portion by condensing laser beam on the wafer, and after the forming an altered portion, forming a p-type nitride semiconductor layer by subjecting the wafer to annealing.