Optoelectronic Substrate Nanovoids for Surface Defect Reduction

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Solution Overview

Problem

Existing substrates for optoelectronic devices made of costly bulk materials like germanium have lattice constant mismatches that lead to undesirable crystalline defects, which hinder the growth of semiconductor components.

Innovation Solution

A multi-layer substrate is formed with a first layer of a crystalline material lattice-matched to the semiconductor components and a second supporting layer of a less expensive material, where crystalline defects are etched to form pores that transform into nanovoids upon heating, reducing defect density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a multi-layer substrate with different crystalline materials is used to reduce cost, then manufacturing cost is reduced, but crystalline defects appear at the surface

Engineering Contradiction:

Improvecrystalline defect densityVSAvoidsubstrate cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent converts harmful crystalline defects into beneficial nanovoids through a two-step process: first etching the first layer to expand defects into pores, then heating to transform pores into nanovoids that attract and sequester defects away from the semiconductor growth surface. This transforms the harmful lattice mismatch defects into useful defect sinks.

Inventive Principle:

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

Solution Approach 2:

The patent utilizes a porous intermediate structure (pores) that forms during etching, which is then transformed into nanovoids. This porous/nanovoid structure serves as a defect sink that attracts crystalline defects away from the surface, reducing defect density in the semiconductor growth region.

Inventive Principle:

Principle #31Porous materials

2Reliability

If etching is performed to expand crystalline defects into pores, then defect density at surface is reduced, but manufacturing process complexity increases

Engineering Contradiction:

Improvecrystalline defect densityVSAvoidmanufacturing process steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs parameter changes in the form of controlled thermal treatment (heating to specific temperatures for specific durations) to transform the physical state of pores into nanovoids. This thermal parameter change drives the defect migration and nanovoid formation process, achieving defect reduction through controlled physical transformation rather than complex mechanical or chemical processes.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If heating is performed to transform pores into nanovoids, then defect attraction increases, but energy consumption increases

Engineering Contradiction:

Improvedefect attraction capabilityVSAvoidheating energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent utilizes a phase transition process where pores transform into nanovoids through thermal heating. This phase transition creates a defect-attracting force that draws crystalline defects into the nanovoids, sequestering them away from the semiconductor growth surface. The phase transition is a fundamental physical process that drives defect migration without requiring additional chemical agents or complex equipment.

Inventive Principle:

Principle #36Phase transitions

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 method significantly reduces the surface crystalline defect density, providing an improved substrate for optoelectronic devices by attracting defects away from the surface, thereby enhancing growth quality.

Implementation Method 1

etching the first layer using first etching conditions thereby causing at least some of the crystalline defects to expand into pores running from the surface of the first layer towards the second layer

Methodology Applied

Scientific EffectEtching:

Implementation Method 2

the first and second layers are heated up to a first temperature for a first period of time within a given environment. This latter step transforms the pores into nanovoids which attract at least some of the undesirable crystalline defects away from the surface

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

the multi-layer substrate is cooled down for a given period of time after which it is reheated at a second temperature for a second period of time within a given environment

Methodology Applied

Scientific EffectCooling: Cooling

Data Source

PatentUS12509798B2Substrates for optoelectronic devices and methods of manufacturing same

Publication Date: 2025.12.30 SCOPRA SCI & GENIE SEC

AI summary

There is described a method of manufacturing a substrate for an optoelectronic device. The method has the steps of: supporting a first layer of a first crystalline material on a second layer of a second crystalline material different from said first crystalline material thereby exposing crystalline defects at a surface of said first layer; etching said first layer using first etching conditions, at least some of said crystalline defects expanding into pores running from said surface of the first layer towards said second layer; and heating said first and second layers up to a first temperature for a first period of time within a given environment, said heating transforming said pores into nanovoids attracting at least some of said crystalline defects away from said surface. In some embodiments, the method has a step of reheating the layers or a step of forming a pore containing region within the first layer.