VCSEL Oxide Confinement Layer Aperture Control via Hole Patterning

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Solution Overview

Problem

Existing methods for oxidizing layers in semiconductor devices, such as VCSELs, are ineffective for materials with low oxygen mobility, like InAlGaAs and InAlAs, and lack precise control over the shape and location of apertures in the confinement layer.

Innovation Solution

A method involving the formation of a pattern of holes through an exposed layer to facilitate oxidation of a to-be-oxidized layer, allowing for controlled formation of apertures in the confinement layer, even in materials with low oxygen mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oxidation is performed from the outer edge of the layer toward the middle portion, then lateral electrical and optical confinement is provided, but oxygen cannot penetrate sufficiently deep into materials with low oxygen mobility such as InAlGaAs and InAlAs

Engineering Contradiction:

Improveoxidation completenessVSAvoidoxidation process feasibility

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the oxidation process into two distinct stages: first oxidizing from the outer edges toward the middle, then performing a second oxidation from the middle outward. This segmentation allows complete oxidation of materials with low oxygen mobility by addressing the penetration limitation through sequential opposite-direction oxidation cycles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic alternation between edge-to-middle oxidation and middle-to-edge oxidation. This periodic action ensures that oxygen has multiple opportunities to penetrate the low-mobility materials from different directions, achieving complete oxidation that would be impossible with a single unidirectional process.

Inventive Principle:

Principle #19Periodic action

2Manufacturing precision

If oxidation is performed from the outer edge toward the middle portion, then lateral confinement is achieved, but precise control over the shape and location of apertures in the confinement layer cannot be obtained

Engineering Contradiction:

Improveaperture shape and location controlVSAvoidoxidation process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary oxidation from the outer edges toward the middle portion before completing the oxidation from the middle outward. This preliminary action allows precise control over where oxidation stops and apertures form, enabling accurate positioning and shaping while managing process complexity through staged execution.

Inventive Principle:

Principle #10Preliminary action

3Length of stationary object

If materials such as InAlGaAs and InAlAs are oxidized from the outer edge, then the oxidation process cannot penetrate sufficiently deep to form a complete confinement layer

Engineering Contradiction:

Improveoxidation penetration depthVSAvoidconfinement layer formation

Core Design Contradiction:

Length of stationary objectVSReliability

Solution Approach 1:

The patent inverts the conventional oxidation approach by performing oxidation from the middle of the layer outward after the initial edge-to-middle oxidation. This inversion allows oxygen to penetrate from the center toward the edges, achieving complete penetration depth in low-mobility materials and ensuring reliable confinement layer formation that unidirectional oxidation cannot achieve.

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

This method enables effective lateral electrical and optical confinement in semiconductor devices by ensuring complete oxidation of the confinement layer, even in materials with low oxygen mobility, and allows for precise control over the shape and location of apertures.

Implementation Method 1

The partial and/or in-process semiconductor, comprising the substrate, the to-be-oxidized layer, the exposed layer having the pattern of holes formed therethrough, and possibly other layers between the substrate and the to-be-oxidized layer, is then exposed to an oxidizing gas (e.g., a gas comprising water vapor). The oxidizing gas oxidizes a portion of the to-be-oxidized layer to form a confinement layer having one or more apertures defined therein

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS12334711B2Fabricating semiconductor devices, such as VCSELs, with an oxide confinement layer

Publication Date: 2025.06.17 MELLANOX TECHNOLOGIES LTD(IL)

AI summary

Methods for forming an at least partially oxidized confinement layer of a semiconductor device and corresponding semiconductor devices are provided. The method comprises forming two or more layers of a semiconductor device on a substrate. The layers include an exposed layer and a to-be-oxidized layer. The to-be-oxidized layer is disposed between the substrate and the exposed layer. The method further comprises etching, using a masking process, a pattern of holes that extend through the exposed layer at least to a first surface of the to-be-oxidized layer. Each hole of the pattern of holes extends in a direction that is transverse to a level plane that is parallel to the first surface of the to-be-oxidized layer. The method further comprises oxidizing the to-be-oxidized layer through the pattern of holes by exposing the two or more layers of the semiconductor device to an oxidizing gas to form a confinement layer.