Two-Stage Groove Formation for Semiconductor Laser Chip Separation
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Solution Overview
Problem
Conventional methods for dividing semiconductor wafers into chips face inefficiencies due to the difficulty in forming deep grooves, especially with laser scribing, which generates debris and limits groove depth, making chip separation challenging.
Innovation Solution
A method involving the formation of a first shallow groove on the wafer, followed by a second narrower groove on the laser bars, allowing for efficient separation of semiconductor lasers into individual chips with reduced contamination and improved yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser scribing is used to form grooves for chip separation, then the grooves can be formed, but debris is generated and groove depth is limited
Solution Approach 1:
The groove formation process is segmented into two distinct stages: first forming a shallow groove across the entire wafer, then forming a deeper groove in the laser bar after separation. This segmentation allows each stage to be optimized independently, achieving deep grooves without excessive debris generation in a single step.
Solution Approach 2:
A shallow groove is formed preliminarily on the wafer before laser bar separation. This preliminary groove formation reduces the subsequent workload and allows the final deep groove to be formed more efficiently with less debris generation, as the preliminary groove provides a starting point for the deeper etching.
2Ease of operation
If deep grooves are required to facilitate chip separation, then separation becomes easier, but conventional methods cannot form considerably deep grooves
Solution Approach 1:
The groove formation is divided into two stages: first a shallow groove is formed on the wafer, then after laser bar separation, a second deeper groove is formed in the laser bar. This segmentation enables achieving considerably deep grooves that facilitate easy chip separation, overcoming the depth limitations of conventional single-stage methods.
Solution Approach 2:
The shallow groove is formed as a preliminary step before laser bar separation. This preliminary action creates an initial groove structure that makes subsequent deep groove formation easier and more precise, ultimately enabling considerably deep grooves that facilitate chip separation.
3Productivity
If grooves and break lines are formed on respective laser bars using conventional methods, then separation can be achieved, but manufacturing efficiency is low
Solution Approach 1:
The groove formation process is merged into a unified two-stage approach: first forming grooves on the entire wafer simultaneously, then forming final grooves on separated laser bars. This merging eliminates the need for repeated groove formation on each individual laser bar, significantly improving manufacturing efficiency.
Solution Approach 2:
Grooves are formed preliminarily on the wafer before laser bar separation. This preliminary groove formation eliminates the need to form grooves on each individual laser bar separately, reducing process complexity and improving manufacturing efficiency by performing the operation in bulk.
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 enhances manufacturing efficiency by enabling deeper groove formation in two stages, improving chip separation performance and yield while minimizing debris and heat-related damages.
Implementation Method 1
laser scribing generates debris
Implementation Method 2
break lines are formed by laser irradiation in the groove
Data Source
AI summary
A method for manufacturing a semiconductor device includes forming a semiconductor laminated structure on a substrate as a wafer including semiconductor laser structures; forming a first groove between the semiconductor laser structures on a major surface of the wafer; separating the wafer to laser bars including at least two of the semiconductor laser structures arrayed in a bar shape, after forming the first groove; forming a second groove in the first groove of the laser bars, the second groove having a width no wider than the first groove; and separating one of the laser bars into respective semiconductor lasers along the second groove.