Vertical GaN Epitaxy Delamination for Reusable Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing vertical semiconductor devices using gallium nitride epitaxy result in significant substrate destruction and wastage, making the process unsustainable and costly due to the need for frequent substrate replacement.
Innovation Solution
A method involving the use of laser radiation with a wavelength greater than the optical band gap of gallium nitride to non-destructively separate the substrate from the semiconductor layer structure, allowing for substrate reuse and reducing material consumption by ensuring mechanical stability through carrier material attachment and controlled laser irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the substrate is removed or partially removed to form the rear electrode, then the semiconductor device can be completed with proper electrode formation, but the substrate is destroyed and cannot be reused, leading to high material consumption and cost
Solution Approach 1:
The substrate is separated from the semiconductor layer structure through laser-induced delamination, dividing the substrate-substrate layer system into separable components. This allows the substrate to be detached and reused while the semiconductor layer structure is transferred to a new substrate for electrode formation.
Solution Approach 2:
Instead of destroying the substrate to form the rear electrode, the substrate is recovered through laser separation and reused for subsequent semiconductor layer growth. The electrode formation is achieved by transferring the semiconductor layer structure to a new substrate, thus recovering the expensive substrate material.
2Loss of substance
If laser radiation is used to separate the substrate from the semiconductor layer structure, then the substrate can be reused reducing material consumption, but the process complexity increases due to the need for carrier material attachment and laser irradiation control
Solution Approach 1:
A carrier material is introduced as an intermediary element to attach to the semiconductor layer structure before laser separation. This carrier material facilitates the controlled delamination process and provides mechanical support during substrate separation, simplifying the overall process control.
Solution Approach 2:
The carrier material is attached to the semiconductor layer structure in advance before the laser separation process. This preliminary action prepares the structure for controlled delamination, ensuring that the separation can be performed cleanly and that the semiconductor layer remains intact during the substrate removal process.
3Loss of substance
If the substrate is reused multiple times for semiconductor layer growth, then material cost and sustainability improve, but the mechanical stability of the substrate may be compromised over repeated processing cycles
Solution Approach 1:
The carrier material serves as a cushioning element that protects the semiconductor layer structure during the laser separation process and subsequent handling. This beforehand cushioning ensures that mechanical stresses during substrate reuse do not compromise the integrity of the separated layers.
Solution Approach 2:
The laser radiation parameters (wavelength, power, pulse duration) are optimized to achieve separation at the substrate-semiconductor layer interface without damaging the substrate or the semiconductor layers. By controlling the laser parameters, the substrate can be separated cleanly and reused without degradation of its mechanical properties.
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 enables a more sustainable and resource-efficient production process, allowing the substrate to be reused multiple times, thereby reducing costs and environmental impact while maintaining device performance.
Implementation Method 1
laser radiation is introduced into the semiconductor layer structure or the substrate, wherein the wavelength of the laser radiation is greater than the optical band gap of gallium nitride, so that the laser radiation causes at least the substrate to separate from at least part of the semiconductor layer structure
Implementation Method 2
laser radiation is introduced into the semiconductor layer structure or the substrate, wherein the wavelength of the laser radiation is greater than the optical band gap of gallium nitride, so that the laser radiation causes at least the substrate to separate from at least part of the semiconductor layer structure
Data Source
AI summary
A method for producing a vertical semiconductor device, in particular a transistor. The device has a semiconductor layer structure for forming a semiconductor device based on gallium nitride and at least two, preferably three, electrodes arranged vertically one above the other, wherein the semiconductor layer structure is applied, in particular grown, on a substrate. The method includes forming a semiconductor layer structure comprising at least one layer based on gallium nitride on the substrate, in particular a foreign substrate. The method includes the introduction of laser radiation into the semiconductor layer structure or the substrate, wherein the wavelength of the laser radiation is greater than the optical band gap of gallium nitride, so that the laser radiation causes at least the substrate to separate from at least part of the semiconductor layer structure.