Semiconductor Chip Mirror Structure for Radiation Extraction

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Solution Overview

Problem

Semiconductor chips face low decoupling efficiency due to internal radiation absorption, with most generated photons being lost within the chip rather than emerging effectively.

Innovation Solution

A semiconductor chip design featuring a mirror structure with a metallic mirror layer and a dielectric layer structure, which reflects radiation back into the chip, preventing absorption and enhancing decoupling efficiency by ensuring a high proportion of radiation is reflected and exits the chip.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If radiation is generated in the active region, then light emission is achieved, but most photons are absorbed within the semiconductor chip due to total internal reflection at interfaces

Engineering Contradiction:
Improveradiation lossVSAvoidoutput efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies total internal reflection, which normally causes harmful photon loss, as a beneficial mechanism by directing reflected radiation toward a mirror structure. The mirror then reflects the radiation back into the active region, converting the harmful reflection into a useful mechanism for enhancing light extraction efficiency.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The mirror structure acts as an intermediary element between the active region and the substrate. It intercepts radiation that would otherwise be lost through absorption in downstream regions and redirects it back into the active region, mediating the interaction between generated photons and the semiconductor structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If a mirror structure is added to reflect radiation back into the semiconductor body, then extraction efficiency is increased, but device complexity increases

Engineering Contradiction:
Improveextraction efficiencyVSAvoidstructure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The mirror is implemented as a thin film structure deposited on the substrate, rather than a bulky mechanical component. This thin-film approach achieves the required optical function while minimizing structural complexity and maintaining compatibility with standard semiconductor manufacturing processes.

Inventive Principle:
Principle #30Flexible shells and thin films

3Productivity

If radiation is reflected back into the semiconductor body multiple times, then more radiation can escape, but absorption in downstream regions increases

Engineering Contradiction:
Improveradiation extractionVSAvoidabsorption loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

Instead of allowing radiation to propagate forward and be absorbed, the mirror inverts the propagation direction by reflecting radiation back toward the active region. This reversal prevents downstream absorption and gives radiation multiple opportunities to escape through the top interface.

Inventive Principle:
Principle #13The other way round (Inversion)

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

The combination of a metallic mirror layer and dielectric layer structure achieves a reflectivity of 80% or more, significantly increasing the decoupling efficiency of the semiconductor chip by minimizing absorption and maximizing radiation output.

Implementation Method 1

During operation of the semiconductor chip, radiation generated in the active region can be reflected back into the semiconductor body by the mirror structure

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the dielectric layer structure comprises a plurality of dielectric layers. These dielectric layers can form a dielectric mirror structure. In particular, the dielectric mirror structure can be configured as a Bragg mirror

Methodology Applied
Scientific EffectOptical interference: Interference

Data Source

PatentEP3200247B1Semiconductor chip and method for manufacturing the same
Publication Date: 2019.06.05 OSRAM OPTO SEMICON GMBH & CO OHG
  • EP3200247B1 patent drawingFigure 1A~1B
  • EP3200247B1 patent drawingFigure 2
  • EP3200247B1 patent drawingFigure 3

AI summary

A semiconductor chip (1) is described, comprising a semiconductor body (2) with a sequence of semiconductor layers including an active region (25) for generating radiation. A mirror structure (3) is arranged on the semiconductor body (2), the mirror structure having a mirror layer (4) and a dielectric layer structure (5) located at least partially between the mirror layer and the semiconductor body. A method for manufacturing a semiconductor chip is also described.