Enlarged Gate Electrode Structure for Low-Resistance Semiconductor Gates
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Solution Overview
Problem
Existing semiconductor manufacturing processes are inadequate for further miniaturization of device sizes on a chip, as they fail to effectively enlarge the space for forming gate electrode structures, leading to increased resistance and reduced performance.
Innovation Solution
A method involving the formation of a gate stack structure with a conductive layer and a gate electrode structure, where the space for the gate electrode is enlarged by etching back the conductive layer, resulting in a gate electrode with a wide upper portion and a narrow lower portion, reducing resistance and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device sizes are miniaturized to increase integration levels, then higher levels of integration are achieved, but the space for forming gate electrode structures becomes insufficient leading to increased resistance
Solution Approach 1:
The gate electrode structure employs an asymmetric geometry with a wider upper portion and a narrower lower portion. This asymmetric design allows the gate electrode to fit within constrained vertical space while maintaining a larger effective gate area at the upper portion, thereby reducing resistance without increasing the overall device footprint.
Solution Approach 2:
The invention transitions from a conventional planar gate structure to a three-dimensional enlarged gate electrode structure. By utilizing vertical dimension and creating an enlarged gate electrode that extends upward with a wider upper portion, the effective gate area is increased without proportionally increasing the lateral device dimensions, thus reducing resistance while maintaining miniaturization.
2Ease of manufacture
If conventional manufacturing processes are used for miniaturization, then existing process compatibility is maintained, but the space for gate electrode structures cannot be effectively enlarged
Solution Approach 1:
The method performs preliminary etching of the conductive layer to create an enlarged space for the gate electrode structure before depositing the gate electrode material. This preliminary action of removing portions of the conductive layer allows subsequent gate electrode deposition to form the desired enlarged structure with wider upper portion, achieving both process compatibility and increased gate space.
Solution Approach 2:
The gate electrode structure is segmented into different portions with different cross-sectional dimensions - a narrower lower portion and a wider upper portion. This segmentation is achieved through selective etching and deposition processes, allowing the structure to occupy optimized space while maintaining manufacturing compatibility with existing processes.
3Reliability
If gate electrode space is enlarged to reduce resistance, then performance is improved, but device size miniaturization becomes more difficult
Solution Approach 1:
The invention resolves the contradiction by utilizing the vertical dimension to enlarge the gate electrode. The enlarged gate electrode structure extends upward from the substrate with a wider upper portion, increasing the effective gate area and reducing resistance without proportionally increasing the lateral device dimensions. This allows performance improvement while maintaining compact device footprint.
Solution Approach 2:
The gate electrode structure exhibits local quality variation with a narrower lower portion near the substrate and a wider upper portion extending upward. This local variation in cross-sectional dimensions allows the structure to achieve reduced resistance through increased effective area while maintaining compatibility with miniaturized device dimensions through optimized spatial distribution.
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 enlarged space for the gate electrode structure reduces the resistance of the gate stack, enabling improved performance and higher levels of integration in semiconductor devices.
Implementation Method 1
Before the gate electrode structure is formed, some portions of the conductive layer are etched back, so that the space for forming the gate electrode structure can be enlarged
Data Source
AI summary
A semiconductor structure and a method for forming the same are provided. The semiconductor structure includes a gate stack structure formed over a substrate. The gate stack structure includes a gate electrode structure having a first portion and a second portion and a first conductive layer below the gate electrode structure. In addition, the first portion of the gate electrode structure is located over the second portion of the gate electrode structure, and a width of a top surface of the first portion of the gate electrode structure is greater than a width of a bottom surface of the second portion of the gate electrode structure.