Semiconductor Mesa Burial Structure for Laser-Modulator Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor integrated devices face challenges in achieving optimal properties for both semiconductor lasers and optical modulators, with issues such as increased optical loss, high threshold current, low emission efficiency, and low relaxation oscillation frequency due to the use of semi-insulating semiconductors for burial, and difficulties in achieving wide-bandwidth optical modulators.
Innovation Solution
The semiconductor integrated device employs a structure where the lower mesas of both the light-emitting and optical modulator portions are buried with semi-insulating semiconductor material to suppress non-radiative recombination, while the upper mesas are buried with resin material of low refractive index, enhancing optical confinement and reducing capacitance in the optical modulator portion, and includes an isolation groove filled with resin for electrical isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the semiconductor mesa is buried by a semi-insulating semiconductor, then the properties of the semiconductor laser are ensured, but the degree of optical confinement in the optical modulator is reduced and optical loss increases
Solution Approach 1:
The patent divides the burial structure into two distinct segments: a lower burial layer made of semi-insulating semiconductor and an upper burial layer made of resin material. This segmentation allows each layer to fulfill different functional requirements - the lower layer ensures laser properties while the upper layer provides optical confinement for the modulator, thereby resolving the contradiction between laser reliability and modulator optical loss
Solution Approach 2:
The patent applies different material properties to different spatial locations: the lower burial layer uses semi-insulating semiconductor with specific electrical properties to protect the laser, while the upper burial layer uses resin material with appropriate optical properties to confine light in the modulator. This local differentiation of material quality enables simultaneous optimization of both laser and modulator performance
2Reliability
If the semiconductor mesa is buried by a resin, then the properties of the optical modulator are improved, but non-radiative recombination is increased in the semiconductor laser
Solution Approach 1:
The dual-layer burial structure segments the protective function: the lower semi-insulating semiconductor layer prevents non-radiative recombination in the laser by providing proper electrical isolation, while the upper resin layer improves modulator properties. This segmentation resolves the contradiction by assigning different materials to different functional roles
Solution Approach 2:
The patent applies different burial materials at different vertical positions: the lower layer uses semi-insulating semiconductor where electrical isolation is critical for laser operation, while the upper layer uses resin where optical properties are more important for modulator performance. This local quality differentiation simultaneously addresses both concerns
3Device complexity
If the semiconductor laser has a ridge structure, then the device complexity is reduced, but the threshold current increases and emission efficiency decreases
Solution Approach 1:
The patent segments the waveguide structure into a mesa portion and a ridge portion, with the mesa providing the active light-emitting region and the ridge providing the waveguide function. This segmentation allows the laser to maintain low threshold current through the mesa structure while still achieving proper light guidance through the ridge, thus resolving the contradiction between structural simplicity and energy efficiency
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 ensures improved properties for both the light-emitting and optical modulator portions, reducing non-radiative recombination and enhancing optical confinement, while maintaining electrical isolation, thereby achieving balanced performance.
Implementation Method 1
the lower mesas including the core layers are buried by the semi-insulating semiconductor, thereby suppressing an increase in non-radiative recombination in the light-emitting portion
Implementation Method 2
the upper mesas are buried by the resin material having a relatively low refractive index (dielectric constant). As a result, the optical modulator portion has a low capacitance and an optical confinement in the optical modulator portion is improved
Data Source
AI summary
A semiconductor integrated device includes a light-emitting portion including a first lower mesa, a first lower buried layer provided on a side surface of the first lower mesa, a first upper mesa provided above the first lower mesa, and a first upper buried layer provided on a side surface of the first upper mesa; and an optical modulator portion including a second lower mesa, a second lower buried layer provided on a side surface of the second lower mesa, a second upper mesa provided above the second lower mesa, and a second upper buried layer provided on a side surface of the second upper mesa. The first and second lower mesas include first and second core layers optically coupled to each other. The first and second lower buried layers are composed of a semi-insulating semiconductor. The first and second upper buried layers are composed of a resin material.