Nitride Semiconductor P-Contact Layer Interface Design

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Solution Overview

Problem

Optoelectronic semiconductor components based on nitride compound semiconductors often experience undesirably high voltage drops at the interface between the p-doped region and the connection layer, leading to reduced efficiency.

Innovation Solution

The p-contact layer of the optoelectronic semiconductor component is designed with a combination of Ga-face and N-face domains at the interface with the connection layer, where the Ga-face domains facilitate p-dopant activation and the N-face domains enable low or no voltage drop during electrical connection, with a preferred ratio of Ga-face domains to N-face domains being at least 10% to 90% and 30% to 60% respectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a p-doped nitride compound semiconductor layer is connected to a connection layer, then electrical connection is achieved, but undesirably high voltage drops occur at the interface

Engineering Contradiction:
Improveelectrical connection qualityVSAvoidvoltage drop
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The p-contact layer is divided into different domains with distinct crystallographic orientations (Ga-face and N-face domains) at the interface with the connection layer. Each domain provides different local properties: Ga-face domains facilitate p-dopant activation while N-face domains enable low voltage drop electrical connection. This local differentiation resolves the contradiction by allowing both good electrical connection and low voltage drop at different locations within the same interface.

Inventive Principle:
Principle #3Local quality

2Reliability

If a p-contact layer is used to connect p-doped region to connection layer, then electrical connection is established, but p-dopant activation is insufficient

Engineering Contradiction:
Improveelectrical connectionVSAvoidp-dopant activation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Different domains within the p-contact layer interface are assigned different crystallographic orientations to perform different functions. Ga-face domains are optimized for p-dopant activation through their specific surface properties, while N-face domains are optimized for electrical connection with minimal voltage drop. This local functional differentiation ensures both adequate dopant activation and reliable electrical connection simultaneously.

Inventive Principle:
Principle #3Local quality

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 configuration reduces the voltage drop at the interface to less than 0.2 V, ensuring efficient electrical connection and effective p-dopant activation while allowing for improved radiation coupling and reduced total reflection of radiation.

Implementation Method 1

The p-contact layer has first domains with a Ga-face alignment and second domains with an N-face alignment at the interface to the connection layer

Methodology Applied
Scientific EffectCrystallographic orientation effect:

Implementation Method 2

the Ga-face domains facilitate p-dopant activation and the N-face domains enable low or no voltage drop during electrical connection

Methodology Applied
Scientific EffectDopant activation through crystallographic orientation:

Data Source

PatentEP2338182B1Optoelectronic semiconductor component
Publication Date: 2018.11.07 OSRAM OPTO SEMICON GMBH & CO OHG
  • EP2338182B1 patent drawingFigure 1~2
  • EP2338182B1 patent drawingFigure 3

AI summary

The invention relates to an optoelectronic semiconductor component, comprising a semiconductor layer sequence (3) which is based on a nitride compound semiconductor and comprises an n-doped region (4), a p-doped region (8), and an active zone (5) disposed between the n-doped region (4) and the p-doped region (8). The p-doped region (8) includes a p-contact layer (7) comprising InxAlyGa1-x-yN, where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, and x + y ≤ 1. The p-contact layer (7) adjoins a connecting layer (9) made of a metal, a metal alloy, or a transparent conductive oxide, wherein on an interface to the connecting layer (9) the p-contact layer (7) comprises first domains (1) having a Ga-face orientation and second domains (2) having an N-face orientation.