Spalling Layer Stress Engineering for III-V Substrate Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing III-V semiconductor devices are inefficient in recovering and reusing expensive substrates, leading to material waste and increased costs.
Innovation Solution
A method involving the deposition of a spalling layer with balanced compressive and tensile stresses, allowing for precise separation of semiconductor devices from substrates, enabling recycling and reuse by inducing fracture at a specific plane within the spalling layer using mechanical force or stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional manufacturing methods are used without engineered stress layers, then device fabrication is simpler, but substrate recovery and reuse become inefficient leading to material waste
Solution Approach 1:
The spalling layer is segmented into multiple thin layers (first layer, second layer, third layer) with alternating stress functions. This segmentation allows the structure to achieve both simplicity in individual layer deposition and complexity in overall functionality for precise fracture control at the interface between layers.
Solution Approach 2:
The spalling layer employs composite material structure with alternating layers of materials having different stress characteristics. The first layer (e.g., GaInAs) provides compressive stress while the second layer (e.g., GaAsP) provides tensile stress, creating a composite structure that enables controlled fracture for substrate recovery.
2Manufacturing precision
If strain-balanced spalling layer is implemented, then precise fracture control is achieved, but manufacturing process becomes more complex
Solution Approach 1:
The invention controls fracture precision by changing parameters of the deposited layers including thickness (2-20 nm per layer), material composition (GaInAs, GaAsP, GaInP), and stress state (compressive vs tensile). These parameter changes enable precise control of the fracture plane location while maintaining manufacturability through standard deposition techniques.
Solution Approach 2:
The spalling layer with engineered stresses is deposited in advance during the device fabrication process, before the actual device operation. This preliminary action of creating the stress-balanced structure ensures that when fracture is needed, it occurs precisely at the predetermined interface without requiring additional complex manufacturing steps later.
3Reliability
If multiple pairs of stress-balanced layers are used, then fracture control is improved, but device structure becomes more complex
Solution Approach 1:
Different regions of the spalling layer structure have different local qualities - the first layer has compressive stress characteristics, the second layer has tensile stress characteristics, and the third layer has tensile stress characteristics. This local quality differentiation within the spalling layer enables reliable fracture control at specific interfaces while maintaining overall structural integrity.
Solution Approach 2:
The compressive stress in the first layer acts as a counterweight to the tensile stress in the second layer, creating a strain-balanced structure. This counterbalancing of stresses ensures that the total strain within the spalling layer is approximately zero, improving fracture control reliability while limiting the number of layer pairs needed.
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 allows for the efficient separation and recycling of substrates and devices, reducing material waste and costs, while maintaining the quality of subsequent device growth.
Implementation Method 1
the spalling layer includes a first layer configured to provide a compressive stress and a second layer configured to provide a tensile stress
Implementation Method 2
dividing the stack substantially at a plane positioned within the spalling layer... the dividing occurs as result of the interface
Implementation Method 3
depositing a spalling layer onto a surface that includes a substrate, depositing a device comprising a III-V material onto the spalling layer
Data Source
AI summary
The present disclosure relates to a method that includes depositing a spalling layer onto a surface that includes a substrate, depositing a device comprising a III-V material onto the spalling layer, resulting in the forming of a stack, and dividing the stack substantially at a plane positioned within the spalling layer to form a first portion that includes the substrate and a second portion that includes the PV device, where the spalling layer includes a first layer configured to provide a compressive stress and a second layer configured to provide a tensile stress, the first layer and the second layer form an interface, the dividing occurs as result of the interface, and the compressive stress and the tensile stress are strain-balanced so that a total strain within the spalling layer is approximately zero.