Photonic Device Monolithic Integration with Buried Semi-Insulating Layers

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Solution Overview

Problem

The integration of active and passive components in photonic devices is complex due to high coupling losses and optical losses from absorption, particularly in semiconductor ridge technologies, which also lead to poor electrical properties and optical mode deformation.

Innovation Solution

A photonic device structure featuring a doped semiconductor substrate with active components laterally and vertically buried by a semi-insulating semiconductor and a doped semiconductor cladding layer, and passive components fully buried in semi-insulating semiconductor, allowing for monolithic integration and reduced optical losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If semiconductor ridge technologies (Ridge or BRS) are used for monolithic integration of active and passive components, then device complexity is reduced and manufacturing is simplified, but optical losses by absorption increase and electrical properties deteriorate

Engineering Contradiction:
Improveintegration complexityVSAvoidoptical absorption loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent segments the semiconductor structure into distinct functional regions: active components with P-type doped cladding layers and passive waveguide components with semi-insulating cladding layers. This segmentation allows each region to be optimized independently - active regions use P-type doping for electrical functionality while passive regions use semi-insulating material to minimize optical absorption losses in the cladding layers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different material properties to different locations within the device. Specifically, P-type doped semiconductor cladding layers are used locally around active components where electrical conductivity is needed, while semi-insulating semiconductor cladding layers are used locally around passive waveguide components where low optical absorption is critical. This local differentiation resolves the contradiction between electrical performance and optical loss.

Inventive Principle:
Principle #3Local quality

2Reliability

If P-type doped semiconductor layers are used in waveguide structures, then electrical properties are improved, but optical losses from absorption increase

Engineering Contradiction:
Improveelectrical propertiesVSAvoidoptical absorption loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent divides the device into electrically-active regions and optically-passive regions. P-type doped layers are segmented to appear only in active components (lasers, modulators, photodetectors) where electrical functionality is required, while semi-insulating layers are segmented to appear only in passive waveguide regions where optical transmission is critical, thus eliminating unnecessary absorption losses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different doping characteristics are applied locally: P-type doping is applied locally to active component cladding layers to ensure proper electrical operation, while semi-insulating material is applied locally to passive waveguide cladding layers to minimize optical absorption. This local quality differentiation allows simultaneous optimization of electrical and optical properties in different device regions.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If hybrid solutions with discrete components and spot size converters are used, then coupling losses between active and passive components are reduced, but manufacturing complexity and assembly cost increase significantly

Engineering Contradiction:
Improvecoupling lossVSAvoidassembly complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent merges the active and passive components into a single monolithic semiconductor structure using integrated growth techniques. The active components and passive waveguides are formed in the same semiconductor substrate with continuous cladding layers, eliminating the need for separate discrete components and external coupling mechanisms like spot size converters. This integration maintains low coupling losses while dramatically simplifying manufacturing and assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal semiconductor platform that can accommodate both active and passive photonic components within the same structure. The monolithic integration approach allows the device to perform multiple functions (generation, modulation, detection, and transmission of optical signals) in a single integrated component, eliminating the need for separate discrete components and complex interconnection assemblies.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach results in reduced coupling and absorption losses, improved optical confinement, and cost-effective production with enhanced electrical insulation between components, enabling efficient optical signal routing and flexible passive waveguide designs.

Implementation Method 1

laterally buried by means of a semi-insulating semiconductor

Methodology Applied
Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 2

vertically buried by means of a doped semiconductor cladding layer, thereby forming a heterojunction structure

Methodology Applied
Scientific EffectHeterojunction: Chemical Bonding

Implementation Method 3

passive component being laterally and vertically buried by means of said semi-insulating semiconductor

Methodology Applied
Scientific EffectOptical absorption reduction: Absorption (EM radiation)

Implementation Method 4

improved optical confinement

Methodology Applied
Scientific EffectOptical confinement: Waveguide (optics)

Data Source

PatentEP2403077B1A photonic device and a method of manufacturing a photonic device
Publication Date: 2017.11.22 ALCATEL LUCENT SA
  • EP2403077B1 patent drawingFigure 1~2B
  • EP2403077B1 patent drawingFigure 3~4B
  • EP2403077B1 patent drawingFigure 5~6B

AI summary

A photonic device and a method of manufacturing a photonic device, wherein on a doped semiconductor substrate (DSS), by monolithic integration, at least one active component (AC1) and at least one passive component (PC) coupled together are produced, each active component (AC1) being laterally buried by means of a semi-insulating semiconductor (SIS) and vertically buried by means of a doped semiconductor cladding layer (CL), in order to have a heterojunction structure, and each passive component (PC) being laterally and vertically buried by means of this semi-insulating semiconductor (SIS). The active components (AC1,AC2) comprise an intrinsic layer (IL) in addition to the layers of the passive components (PC).