Optoelectronic Semiconductor Chip Layers for Low-Loss Light Extraction

Solution Overview

Problem

Existing optoelectronic semiconductor chips face challenges in achieving high radiation output coupling efficiency due to limitations in current spreading and output coupling layers, which result in significant absorption and reflection of primary radiation.

Innovation Solution

The semiconductor chip design includes a semiconductor layer sequence with an active layer, a doped current spreading layer, and an output coupling layer, where the output coupling layer is structured with lower absorption coefficients and defect densities, and features output coupling structures to enhance radiation coupling efficiency, while the current spreading layer has higher conductivity for efficient lateral current distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a doped current spreading layer is used to improve lateral current distribution, then electrical conductivity is improved, but absorption of primary radiation increases

Engineering Contradiction:

Improvecurrent spreading efficiencyVSAvoidradiation absorption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by creating distinct layers with different doping concentrations and material compositions at different positions in the semiconductor structure. The current spreading layer has high doping for electrical conductivity, while the output coupling layer has low doping and optimized composition to minimize radiation absorption, allowing each layer to perform its specific function optimally

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining different semiconductor compounds (such as AlInGaP, AlInP, GaInP) with varying band gaps and optical properties in a layered structure. This composite approach allows the current spreading layer to provide electrical functionality while the output coupling layer provides optimized optical transmission with minimal absorption

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If conventional output coupling layers are used, then manufacturing is simplified, but radiation output coupling efficiency is reduced due to high absorption coefficients and defect densities

Engineering Contradiction:

Improvelayer fabrication simplicityVSAvoidradiation coupling loss

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by optimizing the doping concentration, thickness, and material composition of the output coupling layer. By reducing the doping concentration and carefully controlling the band gap energy relative to the emitted radiation, the absorption coefficient is minimized while maintaining adequate electrical properties and manufacturability

Inventive Principle:

Principle #35Parameter changes

3Loss of energy

If the semiconductor layer sequence is optimized for radiation coupling, then output coupling efficiency is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveradiation absorption lossVSAvoidlayer composition and thickness control

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating distinct layers with different doping concentrations and material compositions at different positions in the semiconductor structure. The current spreading layer has high doping for electrical conductivity, while the output coupling layer has low doping and optimized composition to minimize radiation absorption, allowing each layer to perform its specific function optimally

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies parameter changes by optimizing the doping concentration, thickness, and material composition of the output coupling layer. By reducing the doping concentration and carefully controlling the band gap energy relative to the emitted radiation, the absorption coefficient is minimized while maintaining adequate electrical properties and manufacturability

Inventive Principle:

Principle #35Parameter changes

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 design significantly improves radiation output coupling efficiency by minimizing absorption and maximizing the exit of primary radiation, achieving higher conductivity and reduced defect densities in the output coupling layer, thereby enhancing the overall performance of the semiconductor chip.

Implementation Method 1

The active layer generates primary electromagnetic radiation during intended operation. This occurs by recombination of electrons and holes in the region of the active layer.

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

The output coupling layer comprises a lower absorption coefficient for the primary radiation than the current spreading layer

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 3

The current spreading layer comprises a larger lateral electrical conductivity than the output coupling layer

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS12159956B2Optoelectronic semiconductor chip and method for producing an optoelectronic semiconductor chip

Publication Date: 2024.12.03 AMS OSRAM INT GMBH

AI summary

Provided is an optoelectronic semiconductor chip including a semiconductor layer sequence having an active layer, a doped current spreading layer and an output coupling layer, which are arranged one above the other in this order. The active layer generates primary radiation during intended operation. The current spreading layer includes a larger lateral electrical conductivity than the output coupling layer. The output coupling layer includes output coupling structures for coupling out radiation on an exit side facing away from the active layer. The output coupling layer includes a lower absorption coefficient for primary radiation than the current spreading layer.