GaN Schottky Diode Integration for Antistatic LED Efficiency

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional antistatic GaN-based light emitting devices have complex fabrication processes and degraded luminous efficiency due to the integration of a Schottky diode within the LED structure, which increases manufacturing costs and reduces the effective emitting area.

Innovation Solution

A GaN Schottky diode is formed directly on a p-type GaN-based epitaxial layer, simplifying the fabrication process while maintaining antistatic ability and maximizing the emitting area, by using wet chemical etching to pattern the undoped GaN-based epitaxial layer and ensuring electrical isolation between the epitaxial layers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a Schottky diode is integrated within the LED structure to provide electrostatic protection, then antistatic ability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improveantistatic abilityVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the LED and Schottky diode into a single integrated structure where the Schottky diode is formed directly on the p-type GaN epitaxial layer of the LED. This combination eliminates the need for separate protection components and simplifies the overall device structure while maintaining electrostatic protection functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The p-type GaN epitaxial layer serves dual functions: as the active layer for light emission in the LED and as the substrate for forming the Schottky diode for electrostatic protection. This multi-functionality reduces the number of required layers and simplifies the fabrication process.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a Schottky diode is integrated within the LED structure to provide electrostatic protection, then antistatic ability is improved, but manufacturing cost increases

Engineering Contradiction:

Improveantistatic abilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a Schottky diode is integrated within the LED structure to provide electrostatic protection, then antistatic ability is improved, but the effective emitting area is reduced

Engineering Contradiction:

Improveantistatic abilityVSAvoidemitting area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies local quality by forming the Schottky diode only in a specific region of the p-type GaN epitaxial layer, leaving the majority of the epitaxial layer available for light emission. This localized approach ensures that the protection function is provided without significantly compromising the emitting area.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent transitions from a planar integration approach to a vertical stacking approach, where the Schottky diode is formed in the vertical dimension on the p-type GaN layer. This dimensional change allows both the LED active area and the Schottky diode to coexist with minimal interference, preserving the emitting area while providing electrostatic protection.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 simplifies the fabrication process, reduces manufacturing costs, and maintains the original luminous efficiency of the GaN-based LED by maximizing the emitting area and providing effective electrostatic protection.

Implementation Method 1

a GaN Schottky diode on a part of the p-type GaN-based epitaxial layer, the GaN Schottky diode including an undoped GaN-based epitaxial layer on said part of the p-type GaN-based epitaxial layer

Methodology Applied

Scientific EffectSchottky barrier:

Implementation Method 2

an ohmic contact electrode on a part of the undoped GaN-based epitaxial layer and a Schottky contact electrode on another part of the undoped GaN-based epitaxial layer

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS8217417B2Antistatic gallium nitride based light emitting device and method for fabricating the same

Publication Date: 2012.07.10 QUANZHOU SANAN SEMICON TECH CO LTD

AI summary

The invention provides an antistatic gallium nitride based light emitting device and a method for fabricating the same. The method includes: growing an n-type GaN-based epitaxial layer, an active layer, a p-type GaN-based epitaxial layer and an undoped GaN-based epitaxial layer sequentially on a substrate; etching to remove parts of the layers above, to expose a part of the n-type GaN-based epitaxial layer, with the unetched part defined as an emitting area; etching to remove a part of the undoped GaN-based epitaxial layer; forming an ohmic contact electrode on an exposed part of p-type GaN-based epitaxial layer, and forming a Schottky contact electrode on another part; forming a p-electrode on a transparent conducting layer such that the p-electrode is electrically connected with the ohmic contact electrode; forming an n-electrode on the exposed n-type GaN-based epitaxial layer; and forming a connecting conductor on an insulation layer such that the connecting conductor is electrically connected with the n-electrode and the Schottky contact electrode. By forming a GaN Schottky diode directly on a p-type GaN-based epitaxial layer, the fabrication process is simplified while providing antistatic ability at the same time, and the emitting area is made the maximum use of so as to avoid the drop in the luminous efficiency of the GaN-based LED.