FinFET LED Displays with GaN-Si Buffer Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of light-emitting diodes (LEDs) using finFET structures faces challenges such as lattice and thermal mismatches between gallium-nitride (GaN) and silicon (Si), leading to structural stresses, warping, cracks, and growth defects due to low solid solubility of indium (In) in GaN, which affects the efficiency and reliability of LED displays.
Innovation Solution
The method involves forming doped fin structures with a doped core region, quantum wells, and alternating cladding layers, using quantum dots or spin-on phosphors to create color-emitting regions, which reduces defects and allows for the growth of non-polar facets on conventional substrates, enabling efficient color conversion and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GaN is used on Si substrate, then LED display performance is improved, but lattice mismatch and thermal mismatch cause structural stresses, warping, and cracks
Solution Approach 1:
A multi-layer buffer structure (ALD alumina, sputtered aluminum, and GaN buffer layers) is introduced as an intermediary between the Si substrate and the InGaN quantum wells. This buffer structure acts as a stress-absorbing interface that accommodates the lattice and thermal mismatch between GaN and Si, preventing warping and cracks while enabling high-performance LED operation.
Solution Approach 2:
The patent employs composite material structures including alternating layers of InGaN quantum wells and GaN barrier layers, combined with a multi-component buffer system (alumina/aluminum/GaN). This composite approach allows each layer to contribute specific properties: InGaN for light emission, GaN for structural stability, and the buffer layers for stress management, collectively resolving the contradiction between performance and structural integrity.
2Productivity
If indium (In) concentration is increased, then color emission efficiency is improved, but lattice mismatch between GaN and Si increases
Solution Approach 1:
The patent implements local quality by creating spatially varying In concentration profiles within the quantum well structure. The In concentration is optimized locally in each quantum well layer to achieve desired emission wavelengths, while the overall structure maintains lattice compatibility through the buffer layers. This allows high In concentration (and thus high color emission efficiency) in specific regions without compromising the overall lattice matching of the heterostructure.
3Illumination intensity
If indium (In) concentration is increased, then color emission is enhanced, but solid solubility limitations cause growth defects
Solution Approach 1:
The patent applies preliminary action by forming a complete multi-layer buffer structure (ALD alumina, sputtered aluminum, and GaN buffer layers) before introducing any InGaN quantum wells. This pre-prepared buffer structure creates a defect-tolerant foundation that can accommodate high In concentrations in subsequent layers without propagating growth defects, thereby enabling enhanced color emission while maintaining reliability.
4Ease of manufacture
If conventional substrates are used, then manufacturing cost is reduced, but non-polar facet growth is challenging
Solution Approach 1:
The patent changes the growth parameters by utilizing the specific crystallographic properties of the Si substrate to grow non-polar GaN facets. By controlling the buffer layer composition and growth conditions, the patent enables non-polar facet formation on conventional Si substrates, thereby reducing manufacturing costs while managing the inherent complexity of facet growth through parameter optimization.
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 results in finFET structures with minimal defects, zero dislocation, and efficient color emission, reducing efficiency droop at high current operations while using low-cost substrates, and integrating quantum dots or phosphors for high-efficiency color conversion.
Implementation Method 1
Light-emitting diodes (LEDs) are used in displays for many different types of devices
Implementation Method 2
forming quantum wells over the replacement fin structures
Implementation Method 3
forming a first color emitting region by doping at least one of the quantum wells over at least a first replacement fin structure
Implementation Method 4
the first and second materials are composed of one of quantum dots or spin on phosphors to produce a green color and a red color
Implementation Method 5
forming doped fin structures with a doped core region
Data Source
AI summary
The present disclosure generally relates to semiconductor structures and, more particularly, to finFETs for light emitting diode displays and methods of manufacture. The method includes: forming replacement fin structures with a doped core region, on doped substrate material; forming quantum wells over the replacement fin structures; forming a first color emitting region by doping at least one of the quantum wells over at least a first replacement fin structure of the replacement fin structures, while protecting at least a second replacement fin structure of the replacement fin structures; and forming a second color emitting region by doping another one of the quantum wells over the at least second replacement fin structure of the replacement fin structures, while protecting the first replacement fin structure and other replacement fin structures which are not to be doped.