Suspended Channel Field-Effect Transistor for Mobility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional field-effect transistors face challenges in charge carrier mobility due to substrate interactions and limited control over channel conductance, especially with the gate electrode positioned on top, which affects the on/off ratio and capacitance.
Innovation Solution
The apparatus suspends a portion of the channel member to expose opposing surfaces, allowing for different functional coatings and positioning of electrodes to enhance charge carrier mobility and control channel conductance using ion gel dielectrics and reversible deformation materials, facilitating greater on/off ratios and simplified fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the gate electrode is positioned on top of the channel member, then the device structure is simplified, but the charge carrier mobility and on/off ratio are limited due to substrate interactions
Solution Approach 1:
The patent transitions from a conventional planar top-gate configuration to a three-dimensional suspended channel structure. The channel member is suspended above the substrate, exposing both top and bottom surfaces to gate control. This dimensional change allows the gate electrode to control charge carriers throughout the entire channel volume, significantly improving mobility and on/off ratio while eliminating substrate interactions that limit performance in conventional devices.
Solution Approach 2:
The channel member is divided into suspended and supported portions, with only the suspended portion exposed to gate control. This segmentation allows selective control of charge carriers in the suspended region while isolating it from substrate effects. The channel is effectively segmented into regions with different electrical characteristics, enabling improved device performance.
2Reliability
If the channel member is fully suspended to expose opposing surfaces, then charge carrier mobility and on/off ratio are improved, but the fabrication process becomes more complex
Solution Approach 1:
The fabrication process employs preliminary patterning and release hole formation before final channel release. sacrificial layers are deposited and patterned in advance, creating predefined release pathways. This preliminary action simplifies the subsequent channel release process by providing pre-established access points, reducing the complexity of creating fully suspended structures compared to conventional sequential fabrication approaches.
Solution Approach 2:
Sacrificial layers serve as intermediary materials during fabrication. These temporary structures facilitate channel release and suspension by providing a controlled mechanism to remove substrate material. The sacrificial layers are deposited, patterned, and then removed through the pre-formed release holes, enabling channel suspension without requiring complex direct etching or release processes.
3Adaptability or versatility
If functional coatings are applied to both top and bottom surfaces of the suspended channel, then device functionality is enhanced, but manufacturing precision requirements increase
Solution Approach 1:
The suspended channel structure enables self-service coating application through capillary action and surface tension effects. When the channel is suspended, functional coatings can be applied to both surfaces simultaneously through dip-coating or spray methods, with the coating material naturally distributing itself across the exposed surfaces. The geometry of the suspended structure facilitates uniform coating without requiring complex precision alignment or sequential coating processes.
Solution Approach 2:
The suspended channel configuration provides universal access to both top and bottom surfaces, enabling a single coating process to functionalize both surfaces. This multi-functional approach allows simultaneous application of gate dielectric, functional, or sensing coatings to both surfaces, reducing the need for separate precision coating operations and lowering manufacturing precision requirements compared to conventional planar structures.
4Reliability
If ion gel dielectrics are used for gate control, then capacitance and control efficiency are improved, but the device becomes sensitive to reversible deformation
Solution Approach 1:
The patent embraces the dynamic nature of ion gel dielectrics by designing the suspended channel structure to accommodate reversible deformation. The suspended configuration allows the channel to flex and deform in response to ion gel volume changes without compromising structural integrity. This dynamic design converts the potential stability issue into a functional feature, enabling devices that can respond to mechanical stimuli while maintaining electrical performance.
Solution Approach 2:
The suspended channel member acts as a flexible element that can accommodate the mechanical properties of ion gel dielectrics. The thin, suspended structure allows for reversible deformation when ion gel expands or contracts, maintaining electrical connectivity and gate control functionality. This flexible design approach integrates the mechanical compliance of ion gel with the electrical performance requirements of the field-effect device.
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 configuration increases charge carrier mobility, improves the on/off ratio, and simplifies the fabrication process by reducing substrate effects and enabling efficient control of channel conductance with ion gel dielectrics, while allowing for reversible deformation in electronic devices.
Implementation Method 1
positioning of electrodes to enhance charge carrier mobility and control channel conductance using ion gel dielectrics
Implementation Method 2
enhance charge carrier mobility and control channel conductance
Implementation Method 3
field-effect devices, associated methods and apparatus, and specifically concerns an apparatus comprising a channel member having a portion which is suspended to expose opposing surfaces
Implementation Method 4
positioning of electrodes to enhance charge carrier mobility and control channel conductance using ion gel dielectrics and reversible deformation materials
Data Source
Figure 1~2b
Figure 2c~3
Figure 4a~4d
AI summary
An apparatus comprising a channel member, first and second electrodes configured to enable a flow of electrical current from the first electrode through the channel member to the second electrode, and a supporting substrate configured to support the channel member and the first and second electrodes, wherein one or more of the supporting substrate and electrodes are configured such that a portion of the channel member is suspended to expose opposing surfaces of the portion, the exposed opposing surfaces comprising respective functional coatings thereon configured to facilitate variation of the flow of electrical current through the channel member.