GaN Light-Emitting Element Uniform Micro-Cones

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for forming semiconductor light-emitting elements with GaN-based materials face challenges in creating uniform and regularly arranged micro-cones on the surface of n-type semiconductor layers, leading to issues with light extraction efficiency and reliability due to uneven etching and potential electrode material diffusion.

Innovation Solution

A method involving plasma treatment of the C-plane of GaN followed by wet-etching with an alkaline solution, using a mask layer with openings arranged at equal intervals, to form hexagonal pyramid protrusions that delay etching and ensure uniform micro-cone formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If dry etching is used to form recessed portions, then the etching process can be performed, but the shape and depth of the recessed portions cannot be controlled uniformly

Engineering Contradiction:
Improveuniformity of recessed portionsVSAvoiddifficulty in controlling shape and depth
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by forming a mask layer with a specific pattern before etching. The mask layer pre-defines the shape and arrangement of recessed portions, allowing uniform control during the subsequent etching process. This preliminary patterning step ensures that all recessed portions have consistent shapes and depths, resolving the control issues with direct dry etching.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mask layer serves as an intermediary between the etching process and the semiconductor layer. It mediates the etching action by selectively protecting certain areas while exposing others, thereby controlling the shape and depth of recessed portions. This intermediary element enables precise and uniform formation of etching control points without directly etching the semiconductor material in an uncontrolled manner.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If recessed portions with many C-[-1010] crystal planes are formed, then light extraction efficiency is improved, but etching uniformity and control become difficult

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidetching uniformity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating recessed portions with specific crystal plane orientations in localized areas of the semiconductor layer. By controlling the mask pattern and etching conditions, the recessed portions are formed with predominant C-[-1010] crystal planes that enhance light extraction, while maintaining uniformity across the entire surface. This localized control of crystal plane orientation achieves both high light extraction efficiency and etching uniformity.

Inventive Principle:
Principle #3Local quality

3Device complexity

If wet etching is performed without preliminary treatment, then the process is simple, but the etching rate varies across different surface portions

Engineering Contradiction:
Improveprocess simplicityVSAvoidetching rate consistency
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by performing plasma treatment on the semiconductor layer surface before wet etching. This preliminary plasma treatment modifies the surface properties uniformly, ensuring consistent etching rates across different surface portions during the subsequent wet etching process. The plasma treatment activates the surface and removes contaminants, creating uniform conditions for the wet etchant to act, thereby achieving both process simplicity and etching rate consistency.

Inventive Principle:
Principle #10Preliminary action

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 enables the formation of highly reliable semiconductor light-emitting elements with improved light extraction efficiency by ensuring uniform micro-cone size and arrangement, preventing excessive etching and leakage current.

Implementation Method 1

performing a plasma treatment on a C -

Methodology Applied
Scientific EffectPlasma treatment: Plasma

Implementation Method 2

wet-etching the surface of the semiconductor structure layer to form a plurality of protrusions

Methodology Applied
Scientific EffectWet-etching:

Data Source

PatentEP2975653B1Method for manufacturing semiconductor light-emitting element
Publication Date: 2020.04.08 STANLEY ELECTRIC CO LTD
  • EP2975653B1 patent drawingFigure 1
  • EP2975653B1 patent drawingFigure 2A~2D
  • EP2975653B1 patent drawingFigure 3A~3B

AI summary

Provided are a highly reliable semiconductor light-emitting element having uniform protrusions that are arranged regularly and have the same size and a method of producing the same. The method of producing a semiconductor light-emitting element according to the present invention includes: forming a mask layer having a plurality of openings that are arranged at equal intervals along a crystal axis of a semiconductor structure layer on the surface of the semiconductor structure layer; performing a plasma treatment on the surface of the semiconductor structure layer exposed from the openings in the mask layer; removing the mask layer; and wet-etching the surface of the semiconductor structure layer to form protrusions on the surface of the semiconductor structure layer.