GaN Semiconductor Layer Etching for Low-Resistance Contacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Over-etching occurs during the manufacturing of contact electrodes on P-type and N-type GaN-based semiconductor layers, leading to reduced performance and reliability in GaN-based semiconductor devices.
Innovation Solution
A semiconductor structure and manufacturing method involving the controlled formation of GaN-based layers with specific surface orientations, using wet etching to avoid over-etching and dry etching to reduce contact resistance, along with optional steps like activating P-type doped ions and polarity inversion to enhance layer quality and electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet etching is used to remove semiconductor layers, then over-etching is prevented and manufacturing precision is improved, but contact resistance increases
Solution Approach 1:
The patent divides the etching process into two distinct segments: wet etching for selective layer removal to achieve precise exposure, and dry etching for contact hole formation to ensure low contact resistance. This segmentation allows each etching method to be optimized for its specific function, resolving the contradiction between precision and electrical performance
Solution Approach 2:
The patent applies different etching methods to different regions and purposes: wet etching is used where precision exposure is critical (collecting electrode region), while dry etching is used where low contact resistance is critical (emitter electrode region). This local differentiation of etching quality resolves the contradiction by matching the right etching method to the right functional requirement
2Reliability
If dry etching is used to remove semiconductor layers, then contact resistance is reduced, but over-etching occurs and manufacturing precision deteriorates
Solution Approach 1:
The patent segments the etching process into wet etching for precision-critical areas and dry etching for resistance-critical areas, preventing over-etching in regions where layer thickness control is essential while still achieving low contact resistance in electrode contact regions
Solution Approach 2:
The patent implements local quality by applying wet etching selectively in the collecting electrode region where precision is paramount, and dry etching in the emitter electrode region where low resistance is paramount, thus resolving the contradiction locally rather than globally
3Manufacturing precision
If P-type doped ions are activated before forming N-type layer, then layer quality is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent applies preliminary action by activating P-type doped ions in the first P-type semiconductor layer before forming the N-type semiconductor layer. This pre-activation ensures optimal doping efficiency and layer quality from the outset, preventing defects that would require additional corrective process steps later, thus justifying the added complexity through improved overall process efficiency
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 prevents over-etching and surface inversion, improving the quality of electrical connections and reducing contact resistance, thereby enhancing the performance of GaN-based semiconductor devices.
Implementation Method 1
removing the second P-type semiconductor layer in a collector electrode region and the N-type semiconductor layer in the collector electrode region by wet etching to expose a part of the first P-type semiconductor layer
Implementation Method 2
removing the second P-type semiconductor layer in a base electrode region by dry etching to expose a part of the N-type semiconductor layer
Data Source
AI summary
The present disclosure provides a semiconductor structure and a manufacturing method thereof. In the manufacturing method, a first P-type semiconductor layer is provided, and an N-type semiconductor layer and a second P-type semiconductor layer are formed in sequence on the first P-type semiconductor layer. The first P-type semiconductor layer, the N-type semiconductor layer and the second P-type semiconductor layer all include a GaN-based material. When the first P-type semiconductor layer is provided, its upper surface is controlled to be a Ga surface; when the N-type semiconductor layer is formed, its upper surface is controlled to be an N surface; when the second P-type semiconductor layer is formed, its upper surface is controlled to be an N surface.