Semiconductor Optical Element With Bent Upper Clad Layer
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Solution Overview
Problem
Conventional capacitor-loaded Mach-Zehnder (MZ) type modulators face issues with uneven film thickness distribution of the clad layer, leading to increased optical loss and manufacturing difficulties due to selective growth effects during the regrowth of i type InP clad layer portions.
Innovation Solution
The integrated semiconductor optical element features a waveguide with a multilayer structure where the upper clad layer has alternating conductivity type portions separated in the direction of the waveguide, with an i type upper clad layer connecting these portions, and a manufacturing method that involves depositing conductivity type layers on a semiconductor substrate, using insulating film masks to control the growth and etching of clad layers, ensuring uniform thickness and reducing selective growth effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If i type InP clad layer portions are regrown after removing portions of the p type InP clad layer, then electrical isolation between electrode portions is achieved, but selective growth effects cause uneven film thickness and increased optical loss
Solution Approach 1:
The patent forms the i type InP clad layer portions in advance, before creating the p type InP clad layer portions. This preliminary formation eliminates the need for regrowth operations that cause selective growth effects, thereby maintaining uniform film thickness and reducing optical loss while still achieving the required electrical isolation between electrode portions.
2Reliability
If the clad layer thickness is uneven due to selective growth effects, then manufacturing becomes more difficult, but the electrical isolation function is maintained
Solution Approach 1:
By forming the i type InP clad layer portions before the p type layers, the patent eliminates the need for complex regrowth operations. This preliminary action simplifies the manufacturing process while maintaining the electrical isolation function, as the i type layers are already in place to provide isolation between the electrode portions.
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 a stable and uniform film thickness, reducing optical loss and manufacturing complexity by preventing unevenness in the clad layer, thus enhancing the precision and reliability of the semiconductor optical element.
Implementation Method 1
the clad layer between the portions of the electrode formed so as to be divided along the waveguide is an i type semiconductor layer having high resistance, which prevents leakage between the electrode portions through the clad layer
Implementation Method 2
depositing conductivity type layers on a semiconductor substrate
Implementation Method 3
depositing conductivity type layers on a semiconductor substrate
Implementation Method 4
using insulating film masks to control the growth and etching of clad layers
Data Source
AI summary
The present invention relates to an optical semiconductor integrated element and manufacturing method for same solves difficulty in element manufacture, and reduces optical transmission loss. The present invention is provided with a stripe-shaped waveguide configured from a multilayer structure wherein at least a first conductivity-type lower cladding layer, a waveguide core layer, and an upper cladding layer are layered, and the upper cladding layer is formed using a second conductivity-type upper cladding layer, and an i-type upper cladding layer, which has a bent portion by being shifted in the perpendicular direction with respect to the main extending direction of the waveguide.