AlInGaP Semiconductor Chip Buffer Layer Lattice Mismatch
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Solution Overview
Problem
The production of semiconductor chips with high crystal quality and economic viability is challenging due to issues with lattice mismatch and strain in AlInGaP semiconductor layer sequences grown on GaAs or GaP substrates, leading to inefficient LEDs with shallow potential wells and high internal losses.
Innovation Solution
A method involving a silicon growth substrate with a compressively relaxed buffer layer stack and metamorphic epitaxial growth of the semiconductor layer stack, using a nucleation layer and intermediate layers to manage lattice mismatch and strain, resulting in high-quality AlInGaP semiconductor layers with improved radiation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If AlInGaP semiconductor layer sequence is grown pseudomorphically on GaAs growth substrate, then production cost is reduced, but crystal quality deteriorates due to tensile strains
Solution Approach 1:
The patent introduces an intermediate buffer layer stack between the GaAs growth substrate and the AlInGaP semiconductor layer sequence. This buffer layer stack acts as a mediator that gradually transitions the lattice constant from the GaAs substrate to the AlInGaP layer, thereby reducing tensile strains and improving crystal quality without increasing production cost significantly
Solution Approach 2:
The patent changes the lattice constant parameter gradually through the buffer layer stack, which has a lattice constant that increases from the GaAs substrate value to the AlInGaP layer value. This gradual parameter change allows the semiconductor layer to be grown with high crystal quality while maintaining cost-effectiveness
2Manufacturing precision
If GaP substrates are used to achieve high crystal quality, then crystal quality improves, but production cost increases and wafer size is limited
Solution Approach 1:
The buffer layer stack serves as an intermediary that enables the use of inexpensive GaAs substrates to achieve crystal quality comparable to expensive GaP substrates. This mediator layer eliminates the need to use costly GaP substrates while maintaining high crystal quality standards
Solution Approach 2:
The patent uses inexpensive GaAs substrates instead of expensive GaP substrates, achieving the same crystal quality outcome through the buffer layer approach. The GaAs substrates can be used in large sizes and are much more cost-effective, making mass production economically viable
3Ease of manufacture
If AlInGaP semiconductor layer sequence is grown on GaAs substrate, then production is economical, but radiation efficiency deteriorates due to shallow potential well depth
Solution Approach 1:
The buffer layer stack acts as a mediator that enables the growth of AlInGaP layers with appropriate thickness and composition control. This results in deeper potential wells that improve charge carrier confinement and reduce internal efficiency losses, while maintaining the economic advantage of using GaAs substrates
Solution Approach 2:
The patent optimizes the thickness and composition parameters of the AlInGaP semiconductor layer sequence grown on the buffer layer stack. By controlling these parameters, deeper potential wells are achieved, improving radiation efficiency and reducing internal losses while maintaining production economy
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 production of semiconductor chips with high crystal quality and improved radiation efficiency, while being economically viable and scalable for mass production using large-diameter silicon substrates.
Implementation Method 1
metamorphically, epitaxially growing the semiconductor layer stack on the buffer layer stack
Implementation Method 2
arranging a compressively relaxed buffer layer stack on the growth substrate
Data Source
AI summary
A method of producing an optoelectronic semiconductor chip having a semiconductor layer stack based on a material system AlInGaP includes preparing a growth substrate having a silicon surface, arranging a compressively relaxed buffer layer stack on the growth substrate, and metamorphically, epitaxially growing the semiconductor layer stack on the buffer layer stack, the semiconductor layer stack having an active layer that generates radiation.