GaN Laser Diode Transfer to Carrier Wafer
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Solution Overview
Problem
Current blue and green laser diode technologies face challenges due to high costs, inefficiencies, and sensitivity to temperature, limiting their broader deployment beyond specialty applications, and the manufacturing of high-quality substrates is costly and inefficient.
Innovation Solution
A method for fabricating gallium and nitrogen-containing laser diodes using epitaxial deposition and transfer to a carrier wafer, allowing for the expansion of epitaxial material and reducing costs by using a carrier wafer as a submount, enabling the production of blue-light emitting GaN-based laser devices at a competitive price with LEDs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If heteroepitaxial growth of GaN on foreign substrates (Si, SiC, sapphire) is used, then manufacturing cost is reduced and productivity is improved, but crystalline defects increase making the substrate unacceptable for laser diode operation
Solution Approach 1:
The invention separates the growth substrate from the final device substrate. GaN is grown on inexpensive foreign substrates (segment 1), then transferred to suitable laser diode substrates (segment 2). This segmentation allows each substrate to serve its optimal purpose: foreign substrates for cost-effective growth, and appropriate substrates for defect-free device operation.
Solution Approach 2:
The invention uses an intermediary transfer process to move GaN from the growth substrate to the final substrate. This intermediary step allows the GaN layer to be decoupled from its growth substrate, enabling the use of inexpensive foreign substrates for manufacturing while achieving high crystalline quality on appropriate final substrates.
2Reliability
If free-standing GaN substrates are used, then crystalline quality is improved, but manufacturing cost increases and productivity decreases
Solution Approach 1:
The manufacturing process is segmented into growth on foreign substrates and transfer to final substrates. This allows mass production on inexpensive substrates followed by efficient transfer processes, achieving both high crystalline quality and manufacturing scalability.
Solution Approach 2:
The GaN layer is prepared in advance on foreign substrates using established heteroepitaxial growth techniques. This preliminary action on inexpensive substrates allows subsequent transfer to final substrates without compromising crystalline quality, improving overall manufacturing efficiency.
3Adaptability or versatility
If blue and green laser diodes are developed for general lighting applications, then market penetration is improved, but temperature sensitivity and manufacturing challenges increase
Solution Approach 1:
The invention changes the substrate parameter from foreign substrates to suitable substrates (GaN, GaAs, InP, or their alloys) that better match the thermal and crystallographic requirements of laser diode operation. This parameter change reduces temperature sensitivity while enabling general lighting applications.
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 reduces the cost of blue-light emitting laser diodes to below $0.50 per optical Watt, making them competitive with LEDs and enabling widespread penetration into general lighting markets, while also simplifying the integration and packaging process.
Implementation Method 1
forming epitaxial material overlying the surface region, the epitaxial material comprising an n-type cladding region, an active region comprising at least one active layer overlying the n-type cladding region, and a p-type cladding region overlying the active region
Data Source
AI summary
A method for manufacturing a laser diode device includes providing a substrate having a surface region and forming epitaxial material overlying the surface region, the epitaxial material comprising an n-type cladding region, an active region comprising at least one active layer overlying the n-type cladding region, and a p-type cladding region overlying the active layer region. The epitaxial material is patterned to form a plurality of dice, each of the dice corresponding to at least one laser device, characterized by a first pitch between a pair of dice, the first pitch being less than a design width. Each of the plurality of dice are transferred to a carrier wafer such that each pair of dice is configured with a second pitch between each pair of dice, the second pitch being larger than the first pitch.