InGaAs Epitaxial Layer Crack Control in Semiconductor Laser Scribing
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Solution Overview
Problem
Existing semiconductor wafer and bar manufacturing techniques fail to consistently form suitable cracks perpendicular to the substrate surface during scribing, leading to irregular chip configurations and potential defects in optical semiconductor devices.
Innovation Solution
Incorporating an epitaxially grown InGaAs layer or specific insulating films like SiO2 or SiN, which have openings that expose underlying layers, to prevent vertical cracks and facilitate the formation of vertically extending cracks during scribing, allowing for accurate cleavage and chip separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional scribing is performed on semiconductor wafers without special layer structures, then the scribing process is simple, but the cracks do not extend straight perpendicular to the substrate surface, resulting in irregular chip configurations
Solution Approach 1:
An InGaAs epitaxial layer is formed on the semiconductor substrate before the scribing process. This preliminary layer structure modification enables cracks to extend straight perpendicular to the substrate surface during subsequent scribing, achieving accurate chip configurations without complicating the overall wafer structure
Solution Approach 2:
The introduction of an InGaAs epitaxial layer changes the physical and mechanical parameters of the wafer surface. This parameter change affects crack propagation behavior during scribing, enabling vertical crack extension and improving manufacturing precision without requiring complex structural modifications
2Manufacturing precision
If additional epitaxial layers are added to control crack formation, then chip separation accuracy improves, but manufacturing process complexity increases
Solution Approach 1:
The InGaAs epitaxial layer is formed selectively in regions where crack control is needed, rather than uniformly across the entire wafer. This local modification achieves improved chip separation accuracy while minimizing the impact on overall manufacturing process complexity
Solution Approach 2:
The semiconductor wafer is constructed as a composite structure with an InGaAs epitaxial layer on top of the base semiconductor substrate. This composite material approach enables precise crack propagation control during scribing, achieving accurate chip separation while maintaining relatively simple manufacturing processes
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 ensures the formation of vertically extending cracks, enhancing the accuracy and quality of chip configurations, reducing production costs, and improving manufacturing productivity by eliminating the need for additional wafer regions for accommodating cleavage variations.
Implementation Method 1
a semiconductor layer which is provided on the substrate layer and includes one or more layers epitaxially grown on the substrate layer
Data Source
AI summary
A semiconductor wafer has a plurality of optical semiconductor devices (namely, semiconductor lasers) which are formed from epitaxially grown layers and arranged across the surface of the semiconductor wafer. The InGaAs epitaxial layer of the semiconductor wafer has an opening (or groove) which continuously extends along and between the plurality of optical semiconductor devices, and which exposes the layer underlying the InGaAs epitaxial layer to at least the layer overlying the InGaAs epitaxial layer. The semiconductor wafer may be scribed along this opening to form a vertically extending crack therein.