Optoelectronic Semiconductor Chip Reflection-Enhancing Dielectric Layer

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Solution Overview

Problem

Optoelectronic semiconductor chips, such as LED chips, face absorption losses due to metallic connection layers, which reduce the efficiency of radiation emission.

Innovation Solution

Incorporating a reflection-enhancing dielectric layer sequence with alternating layers of different refractive indices between the semiconductor layers and metallic connection layers, along with transparent conductive layers, to reflect emitted radiation back into the semiconductor chip and reduce absorption losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metallic connection layers are applied to the semiconductor layers for electrical contacting, then good electrical contact is achieved, but radiation absorption increases and efficiency decreases

Engineering Contradiction:

Improveelectrical contact qualityVSAvoidradiation absorption loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

A transparent dielectric layer is introduced as an intermediary between the metallic connection layer and the semiconductor layer. This intermediate layer has low absorption coefficient for the emitted radiation wavelength, allowing radiation to pass through with minimal absorption while still enabling electrical contact through the metallic layer.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection structure uses a composite of multiple materials: a metallic layer for electrical contact, a transparent dielectric layer for radiation transmission, and potentially a reflection-enhancing layer. This composite structure combines the advantages of each material while mitigating their individual disadvantages.

Inventive Principle:

Principle #40Composite materials

2Loss of energy

If a transparent dielectric layer is introduced between the metallic connection layer and semiconductor layer, then radiation absorption is reduced, but device structure becomes more complex

Engineering Contradiction:

Improveradiation absorption lossVSAvoidlayer structure complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The transparent dielectric layer serves multiple functions simultaneously: it acts as a radiation transmission layer with low absorption, provides electrical insulation between the metallic connection layer and semiconductor, and can serve as an adhesion layer or stress relief layer. This multi-functionality reduces the need for additional separate layers.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of energy

If the metallic connection layer is made thinner to reduce absorption, then radiation transmission improves, but electrical contact quality deteriorates

Engineering Contradiction:

Improveradiation absorption lossVSAvoidelectrical contact quality

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The transparent dielectric layer acts as a mediator that allows the metallic connection layer to be optimized for electrical contact (adequate thickness for low contact resistance) while the dielectric layer ensures radiation transmission with minimal absorption. The dielectric layer compensates for the increased metallic layer thickness by providing a low-absorption path for radiation.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the efficiency of the optoelectronic semiconductor chip by minimizing radiation absorption in the metallic connection layers while maintaining good current spreading and electrical contact.

Implementation Method 1

a reflection-enhancing dielectric layer sequence is advantageously arranged between the p-doped semiconductor layer and the first metallic connection layer, which dielectric layer sequence includes a plurality of dielectric layers with different refractive indices. Radiation emitted from the active layer in the direction of the first metallic connection layer is advantageously reflected back at least in part by the reflection-enhancing dielectric layer sequence

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

a reflection-enhancing dielectric layer sequence, which dielectric layer sequence includes a plurality of dielectric layers with different refractive indices

Methodology Applied

Scientific EffectOptical interference: Interference

Data Source

PatentUS10079329B2Optoelectronic semiconductor chip

Publication Date: 2018.09.18 OSRAM OLED

AI summary

According to the present disclosure, optoelectronic semiconductor chip includes at least one n-doped semiconductor layer, at least one p-doped semiconductor layer and one active layer arranged between the at least one n-doped semiconductor layer and the at least one p-doped semiconductor layer. The p-doped semiconductor layer is electrically contacted by means of a first metallic connection layer, and a reflection-enhancing dielectric layer sequence is arranged between the p-doped semiconductor layer and the first connection layer, which dielectric layer sequence includes a plurality of dielectric layers with different refractive indices.