Optoelectronic Component Thermal Stress Reduction via Buffer Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of highly efficient optoelectronic components, particularly light-emitting diodes emitting in the green or blue spectrum, faces challenges due to high manufacturing complexity and scalability issues, leading to reduced efficiency and yield, with existing methods using sapphire growth substrates that require complex processes and generate stresses within the components.
Innovation Solution
A method utilizing a silicon-based growth substrate with a multilayer buffer layer sequence to reduce thermal stresses, allowing for epitaxial deposition of a nitride compound semiconductor layer sequence, which is then contacted directly without severing the buffer layer, enabling efficient light extraction and electrical contacting while avoiding mechanical stress and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sapphire growth substrate is used for producing optoelectronic components, then the components can be manufactured, but the manufacturing complexity increases and scalability is reduced
Solution Approach 1:
The patent changes the substrate material parameter from sapphire to silicon, which has different thermal and mechanical properties. This parameter change simplifies the manufacturing process by eliminating the need for complex laser lift-off procedures and reduces manufacturing complexity while maintaining component efficiency
Solution Approach 2:
The patent extracts and removes the sapphire growth substrate from the final component structure through dissolution or laser lift-off, leaving only the necessary functional layers. This extraction eliminates the harmful sapphire substrate while preserving the optoelectronic functionality, reducing manufacturing complexity
2Ease of operation
If a sapphire growth substrate is dissolved or removed through laser lift-off, then the optoelectronic component can be released, but stresses are generated within the component reducing efficiency and yield
Solution Approach 1:
The patent introduces a buffer layer sequence as an intermediary between the silicon substrate and the optoelectronic layers. This buffer layer acts as a stress-absorbing mediator that compensates for thermal expansion differences, preventing stress generation during substrate removal and maintaining component efficiency
Solution Approach 2:
The buffer layer sequence is deposited beforehand on the silicon substrate to provide mechanical cushioning and stress compensation before the optoelectronic layers are grown. This prior cushioning prevents stress-induced defects and maintains component yield during the substrate removal process
3Ease of manufacture
If the multilayer buffer layer sequence is severed to contact the epitaxially grown layer sequence, then electrical contacting is achieved, but light extraction efficiency is reduced
Solution Approach 1:
The patent transitions from planar contacting to three-dimensional contacting by forming contact holes through the buffer layer sequence. This dimensional change allows electrical contact to be established without severing the buffer layer, maintaining both manufacturability and light extraction efficiency through vertical contact paths
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 the large-scale production of optoelectronic components with low forward voltage and efficient light decoupling, reducing thermal stresses and maintaining component efficiency, while allowing for scalable and cost-effective manufacturing.
Implementation Method 1
A growth substrate is provided which contains silicon or even consists of it in one embodiment. Material containing silicon as a growth substrate has a first coefficient of thermal expansion. A multilayer buffer layer sequence is then applied to the growth substrate. A layer sequence with a second thermal expansion coefficient that differs from the first thermal expansion coefficient is then epitaxially deposited on the multilayer buffer layer sequence.
Implementation Method 2
The layer sequence also includes an active layer suitable for emitting electromagnetic radiation.
Implementation Method 3
A layer sequence with a second thermal expansion coefficient that differs from the first thermal expansion coefficient is then epitaxially deposited on the multilayer buffer layer sequence.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for producing an optoelectronic component. According to said method, an epitaxial growth substrate (10) having a first coefficient of thermal expansion is made available. A multi-layer buffer layer sequence (11) is applied to the substrate. A layer sequence (2) which has a second coefficient of thermal expansion different from the first coefficient of thermal expansion is epitaxially deposited. The layer sequence further comprises an active layer for emitting electromagnetic radiation. A carrier substrate (15) is then applied to the epitaxially deposited layer sequence (2). The epitaxial growth substrate (10) is removed and the multi-layer buffer layer sequence (11) is structured (17) to increase a coupling out of electromagnetic radiation. The epitaxially deposited layer sequence (2) is then contacted.