Gate-All-Around Semiconductor Device Channel Control
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Solution Overview
Problem
Conventional semiconductor devices face challenges in controlling channel current due to the short-channel effect, leading to leakage current and inconsistent electrical performance, which affects device performance and integration levels.
Innovation Solution
A method involving the formation of sacrificial layers, liner layers, and a hard mask layer on a substrate, followed by etching to create fins and a dummy gate structure, which is then replaced by a metal gate structure to form a gate-all-around structure, ensuring consistent electrical performance by isolating the top channel and utilizing the non-top channel for electrical operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional planar semiconductor devices are used, then manufacturing process is simple, but channel current control is weak and short-channel effect occurs
Solution Approach 1:
The patent transitions from conventional planar (2D) gate structures to three-dimensional gate-all-around structures that wrap around the channel from all directions. This dimensional change enables the gate to control carrier flow at the channel interface from top, bottom, and sidewalls, dramatically improving channel current control and suppressing short-channel effects while maintaining manufacturing feasibility through advanced fabrication techniques.
2Productivity
If device size is shrunk to increase integration density, then component density increases, but short-channel effect worsens and leakage current increases
Solution Approach 1:
By implementing gate structures that extend vertically and wrap around channel sidewalls in three dimensions, the invention achieves effective channel control even at reduced device dimensions. The gate-all-around configuration provides superior electrostatic control that suppresses leakage current while enabling continued device scaling and increased integration density.
Solution Approach 2:
The gate structure is nested around the channel region, with the gate material conformally coating the channel sidewalls and extending over the channel top and bottom surfaces. This nested configuration ensures the gate is in close proximity to the channel interface from all directions, maximizing control efficiency at scaled dimensions.
3Reliability
If gate-all-around structure is formed, then channel current control is improved and short-channel effect is suppressed, but device complexity increases
Solution Approach 1:
The gate-all-around structure is formed through segmented fabrication steps, including separate processes for creating the gate material layer, forming sidewall spacers, and defining gate regions. This segmentation allows complex three-dimensional gate structures to be built incrementally using established manufacturing techniques, managing process complexity while achieving superior device performance.
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 enhances the effective length and control ability of the metal gate structure, improving the overall electrical performance and quality of the semiconductor device by ensuring consistent electrical performance across channels.
Implementation Method 1
A device channel formed by a thin silicon film in a gate-all-around structure may be surrounded by a gate of the device, and may be controlled only by the gate
Implementation Method 2
sequentially etching the hard mask layer, the at least two sacrificial layers, the liner layer, and a portion of the substrate
Data Source
AI summary
A semiconductor device and a method for forming the semiconductor device are provided. The method includes providing a substrate, sequentially forming at least two sacrificial layers on the substrate, and forming a liner layer between any adjacent sacrificial layers of the at least two sacrificial layers. The method also includes forming a hard mask layer on a top layer of the at least two sacrificial layers, and sequentially etching the hard mask layer, the at least two sacrificial layers, the liner layer, and a portion of the substrate, thereby forming a plurality of fins that are discretely arranged on a remaining portion of the substrate. The method also includes forming a dummy gate structure across the plurality of fins on the remaining portion of the substrate, and removing a portion of the at least two sacrificial layers under the dummy gate structure, thereby forming tunnels.