Suspended Membrane Thinned Zone for Direct Bandgap
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Solution Overview
Problem
Existing semiconductor structures with suspended membranes made of crystalline semiconductor compounds face challenges in achieving improved optical and electronic properties due to nonuniform energy-band structures caused by biaxial tensile deformation, leading to decreased emission efficiency and wavelength broadening in optoelectronic devices.
Innovation Solution
A semiconductor structure with a central segment under tensile stress, featuring a thinned zone and lateral segments that maintain the central segment suspended along multiple deformation axes, where the thinned zone has a direct energy-band structure and potential barriers, enhancing optical and electronic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a suspended membrane structure with biaxial tensile deformation is used, then the energy-band structure becomes indirect, but emission efficiency decreases and wavelength broadening occurs
Solution Approach 1:
The patent introduces a thinned zone in the central segment of the suspended membrane, creating a local region with different thickness properties. This local modification allows the thinned zone to maintain a direct energy-band structure while the rest of the membrane provides mechanical support and tensile stress, thereby resolving the contradiction between emission efficiency and energy-band structure uniformity
Solution Approach 2:
The suspended membrane is divided into distinct segments: a central segment containing the thinned zone and lateral segments forming tensioning arms. This segmentation allows different regions to serve different functions - the thinned zone optimizes optical properties while the lateral segments maintain mechanical stability and tensile stress
2Reliability
If the membrane thickness is reduced to create a thinned zone, then direct energy-band structure is achieved, but mechanical strength may be compromised
Solution Approach 1:
The thinned zone is created only in the central segment where optical emission is required, while the lateral segments and peripheral regions maintain their original thickness to provide mechanical support. This localized thinning achieves the desired direct energy-band structure without compromising overall membrane strength
Solution Approach 2:
The membrane is first formed with uniform thickness and then selectively thinned in the central zone through controlled removal processes. This preliminary formation followed by selective modification ensures that the structural integrity is established before creating the optically active thinned region
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 structure improves emission efficiency and reduces electron coupling between direct and indirect valleys, resulting in enhanced optical and electronic performance by maintaining a direct band structure and confining electrons within potential barriers.
Implementation Method 1
The thinned zone has a direct energy-band structure and potential barriers, enhancing optical and electronic properties
Implementation Method 2
a central segment that is tensilely stressed in a plane parallel to the carrier layer; and a plurality of lateral segments that are opposite one another with respect to the central segment and arranged so as to keep the central segment suspended and tensilely stressed along at least two separate deformation axes
Data Source
AI summary
A semiconductor structure including a semiconductor layer made of a crystalline semiconductor compound, a portion of the semiconductor layer which forms a suspended membrane above a carrier layer, the suspended membrane being formed from a tensilely stressed central segment and a plurality of lateral segments forming tensioning arms. The central segment includes at least one zone of thinned thickness.