GaN Epitaxial Layer Transfer with Protection Layer Planarization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the fabrication of GaN-based power semiconductor devices, the detachment process using laser lift-off technology often damages the epitaxial structure, leading to increased leakage current and reduced breakdown voltage due to the formation of a rough detaching surface.
Innovation Solution
A method involving the formation of an epitaxial layer with a first transition layer, a protection layer, and an active structure layer, where the protection layer is formed to cover the active structure layer partially, and the first transition layer is etched to create a planarization surface, reducing structural damage during detachment and enhancing the semiconductor's performance by minimizing leakage current and increasing breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser lift-off process is used to detach the growth substrate, then the epitaxial layer can be transferred to the transfer substrate, but the epitaxial structure is damaged causing increased leakage current and reduced breakdown voltage
Solution Approach 1:
A protection layer is formed on the epitaxial structure before the laser lift-off process. This protective measure is taken in advance to prevent damage to the active structure layer during the subsequent detachment process, thereby maintaining the integrity of the epitaxial structure while enabling successful transfer to the transfer substrate
Solution Approach 2:
The protection layer acts as an intermediary between the laser lift-off process and the active structure layer. It absorbs the laser energy and provides mechanical protection during detachment, preventing direct damage to the active structure layer while allowing the transfer process to proceed
2Reliability
If the protection layer is formed to protect the active structure layer, then structural damage is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The epitaxial structure is segmented into functional layers: the active structure layer, the protection layer, and the first transition layer. This segmentation allows the protection layer to be formed as a separate component that can be independently optimized for its protective function while maintaining the overall structure's functionality
Solution Approach 2:
The first transition layer is designed with specific material parameters (laser energy absorption characteristics) that allow it to be selectively removed during the laser lift-off process. This parameter optimization enables the protection layer to remain intact while facilitating the detachment process
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
The method effectively reduces the damage to the epitaxial structure during detachment, thereby decreasing leakage current and increasing breakdown voltage, improving the performance of GaN-based power semiconductor devices.
Implementation Method 1
detaching the growth substrate by a laser lift-off process
Implementation Method 2
a laser energy of the laser lift-off process is greater than a band gap energy of the first transition layer
Data Source
AI summary
Disclosed are a semiconductor structure and a method for manufacturing a semiconductor structure, the method includes: forming a first transition layer, a protection layer and an active structure layer sequentially epitaxially on a side of a growth substrate, where a surface, away from the growth substrate, of the first transition layer is a two-dimensional flat surface; on a first plane, an orthographic projection of the active structure layer is at least partially covered by an orthographic projection of the protection layer, and the first plane is perpendicular to an arrangement direction of the protection layer and the active structure layer; detaching the growth substrate by a laser lift-off process, to make the epitaxial layer transferred to a transfer substrate; etching the first transition layer up to the protection layer, to make a surface, away from the active structure layer, of the protection layer to be a planarization surface.