Butt-Joint Semiconductor Laser With Disordered Interface Region

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The integration of semiconductor laser and optical modulator or waveguide devices on a single substrate using butt joint growth results in deteriorated crystal quality due to differences in crystal compositions and lattice constants, leading to reliability issues and carrier concentration at the butt joint interface.

Innovation Solution

A semiconductor device is manufactured by forming a semiconductor laser part with an active layer and an adjacent optical modulator or waveguide part, where a disordering process is applied to the contact portions to create a disordered region that is transparent to laser oscillation light, thereby improving crystal quality and reducing carrier concentration at the interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If butt joint growth is performed on a complex lateral surface with different crystal compositions and lattice constants, then integration of different optical devices is achieved, but crystal quality of the butt joint growth layer deteriorates

Engineering Contradiction:

Improveintegration of different optical devicesVSAvoidcrystal quality

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The active layer is segmented into a first active layer portion and a second active layer portion with different crystal compositions and lattice constants. This segmentation allows each portion to be optimized for its specific function while reducing the negative effects of lattice mismatch at the butt joint interface, thereby maintaining crystal quality during integration of different optical devices.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the active layer are assigned different crystal compositions and lattice constants according to their specific functional requirements. The first active layer portion has composition optimized for laser operation, while the second active layer portion has composition optimized for modulation or waveguide functions. This local optimization maintains high crystal quality in each region while enabling device integration.

Inventive Principle:

Principle #3Local quality

2Reliability

If strained active layer is used to improve device performance, then optical characteristics are enhanced, but crystal quality at the butt joint interface significantly deteriorates

Engineering Contradiction:

Improveoptical characteristicsVSAvoidcrystal quality at butt joint interface

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The strained active layer is divided into multiple portions with different strain characteristics. The first active layer portion maintains the strained structure for enhanced optical performance, while the second active layer portion has adjusted strain characteristics to reduce lattice mismatch at the butt joint interface, preventing crystal quality deterioration.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The crystal composition parameters and lattice constants are locally adjusted in different active layer portions. By changing these parameters in the second active layer portion near the butt joint interface, the lattice mismatch is reduced, preventing crystal quality deterioration while maintaining the strained structure's optical benefits in the first active layer portion.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If carriers are injected into the active layer for operation, then device functionality is achieved, but carriers concentrate at the butt joint interface decreasing reliability

Engineering Contradiction:

Improvedevice functionalityVSAvoidcarrier concentration at butt joint interface

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The active layer is designed with different crystal compositions in different portions, creating variations in carrier concentration and mobility characteristics. The second active layer portion near the butt joint interface has composition optimized to reduce carrier concentration, preventing harmful carrier accumulation while the first active layer portion maintains composition optimized for device operation and functionality.

Inventive Principle:

Principle #3Local quality

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 disordered region suppresses the deterioration of device characteristics and enhances the reliability of the semiconductor device by improving crystal quality and reducing carrier concentration at the butt joint interface.

Implementation Method 1

a disordering process is applied to the contact portions to create a disordered region

Methodology Applied

Scientific EffectDisordering:

Data Source

PatentUS10903620B2Semiconductor device, and method for manufacturing semiconductor device

Publication Date: 2021.01.26 MITSUBISHI ELECTRIC CORP

AI summary

There are included: a substrate; a semiconductor laser part formed on the substrate by stacking a plurality of layers including an active layer; and an adjacent part formed on the substrate by stacking a plurality of layers including a core layer, and being an optical modulator or an optical waveguide in contact with the semiconductor laser part through butt joint joining thereto. In a semiconductor device including the semiconductor laser part and the adjacent part which are joined in a butt joint manner, at least a portion, of the semiconductor laser part, that is contact with the adjacent part is disordered.