GaN PN Junction Structure Using Wet Etching for P-Type Contact
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Solution Overview
Problem
The challenge in manufacturing GaN-based semiconductor devices lies in the difficulty of creating effective contact electrodes for P-type GaN-based semiconductor layers, particularly due to issues with over-etching and passivation of dopant ions during the etching process.
Innovation Solution
A semiconductor structure and manufacturing method involving a P-type semiconductor layer with a Ga surface and a first N-type semiconductor layer with an N surface, where wet etching is used to expose the P-type layer, avoiding over-etching and passivation problems, and optionally activating P-type doped ions to improve junction quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dry etching is used to remove the first N-type semiconductor layer, then the etching process can be controlled, but over-etching occurs and P-type doped ions are passivated, degrading the PN junction quality
Solution Approach 1:
The patent replaces dry etching (physical/chemical vapor process) with wet etching (liquid chemical process) to remove the first N-type semiconductor layer. This substitution eliminates the passivation of P-type doped ions that occurs with dry etching, thereby maintaining PN junction quality while achieving sufficient etching control through the liquid etchant's selective action on the N-type layer.
2Reliability
If the first N-type semiconductor layer is removed to expose the P-type layer, then electrical connection is improved, but over-etching damages the P-type layer and reduces hole carrier concentration
Solution Approach 1:
The patent uses wet etching instead of dry etching to remove the first N-type semiconductor layer. The liquid etchant provides selective removal of the N-type layer without attacking the P-type layer, thus exposing the P-type layer for electrical connection while preventing over-etching damage and maintaining hole carrier concentration.
Solution Approach 2:
The patent introduces a second N-type semiconductor layer as an intermediary between the P-type layer and the first N-type layer. This intermediate layer acts as a protective buffer during etching processes, allowing selective removal of the first N-type layer while preserving the P-type layer integrity, and can be selectively removed later in specific regions to enable electrical connections.
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 prevents over-etching and maintains hole carrier concentration, ensuring accurate electrical connections and improved PN junction quality by using wet etching instead of dry etching and activating P-type doped ions to enhance the semiconductor device performance.
Implementation Method 1
removing a part of the first N-type semiconductor layer by wet etching to expose a part of the P-type semiconductor layer
Implementation Method 2
before the first N-type semiconductor layer is formed on the P-type semiconductor layer, a P-type doped ion in the P-type semiconductor layer is activated
Data Source
AI summary
The present disclosure provides a semiconductor structure and a manufacturing method thereof. In the manufacturing method, a P-type semiconductor layer is provided, where the P-type semiconductor layer includes a GaN-based material and an upper surface of the P-type semiconductor layer is a Ga surface. A first N-type semiconductor layer is formed on the P-type semiconductor layer, where the first N-type semiconductor layer comprises a GaN-based material. An upper surface of the first N-type semiconductor layer is an N surface. A part of the first N-type semiconductor layer is removed by wet etching to expose a part of the P-type semiconductor layer.