Segmented LED Structure With Embedded Transistors and Trench Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Manufacturing small LED pixel systems with control electronics is costly and difficult due to the need for complex processing and high associated costs, especially with monolithic segmented LEDs constructed using etched gallium nitride mesas.
Innovation Solution
The integration of embedded transistors and transparent conductors to form monolithic segmented LEDs without etched individual mesas, using a substrate with trenches to incorporate control electronics and reduce edge losses, allowing for a more cost-effective combination of transistors and LED structures at the wafer scale.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If etched gallium nitride mesas are used to construct monolithic segmented LEDs, then precise control and mechanical soundness are achieved, but manufacturing complexity and cost increase significantly
Solution Approach 1:
The device is divided into discrete pixel regions separated by trenches, with each pixel containing its own embedded transistor and LED structure. This segmentation allows independent control of each pixel while maintaining a simplified monolithic fabrication process, resolving the contradiction between precise control and manufacturing complexity
Solution Approach 2:
Transistors are embedded within the substrate beneath the LED structures, with the transistor gate positioned under the active region. This nesting approach integrates control electronics directly into the device architecture, achieving precise pixel control without requiring separate control circuits, thereby reducing overall device complexity
2Measurement precision
If etched gallium nitride mesas are used to construct monolithic segmented LEDs, then precise control is achieved, but manufacturing cost increases
Solution Approach 1:
The fabrication process merges LED growth and transistor formation into a single epitaxial growth sequence on the substrate. Both the LED active regions and transistor structures are created simultaneously using standard MOCVD or MBE techniques, eliminating the need for separate processing steps and reducing manufacturing cost while maintaining precise control
Solution Approach 2:
Transistors are formed preliminarily during the epitaxial growth process before the LED structures are completed. The transistor regions are prepared in advance within the substrate, allowing subsequent LED growth to proceed without additional complex processing, thereby reducing manufacturing cost while ensuring precise control architecture
3Loss of energy
If trenches are introduced to separate pixel regions, then edge losses are reduced, but device structure becomes more complex
Solution Approach 1:
Trenches are introduced to extract and remove the harmful edge effects from the active pixel regions. The trenches create physical separation between adjacent pixels, preventing edge-related energy losses and interference, while the simple trench geometry minimizes the addition of structural complexity
Data Source
AI summary
A device may include a substrate having a first embedded transistor in a first region and a second embedded transistor in a second region. The first region and the second region may be separated by trench extending through at least a portion of an epitaxial layer formed on the substrate. The first embedded transistor may be connected to a first light emitting diode (LED) and the second embedded transistor may be connected to a second LED. A first optical isolation layer may be between the epitaxial layer and the first region of the substrate. A second optical isolation layer may be between the epitaxial layer and the second region of the substrate.