FinFET Gate Structure Acute Angle Sidewall Design
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Solution Overview
Problem
The semiconductor industry faces challenges in fabricating finFET transistors with precise control over fin formation and gate structure, which affects the electrical performance and density of semiconductor devices.
Innovation Solution
A method for manufacturing finFET transistors involves forming semiconductor fins on a substrate, using epitaxial growth and patterning techniques, followed by the formation of isolation structures, interlayer dielectrics, dummy gates, and metal gates, with a replacement gate process to improve electrical performance by ensuring accurate fin geometry and gate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication methods are used for finFET transistors, then manufacturing process is simpler, but manufacturing precision of fin geometry and gate alignment deteriorates
Solution Approach 1:
The method performs preliminary patterning of the fin structure before gate formation, establishing precise fin geometry upfront. The gate is then formed using a separate patterning step that aligns to the pre-formed fins, allowing each structure to be optimized independently for precision while managing overall process complexity.
Solution Approach 2:
The fabrication process is segmented into distinct stages: fin formation through epitaxial growth and patterning, followed by gate formation through separate patterning and deposition steps. This segmentation allows independent optimization of each structure's precision while controlling overall process complexity.
2Productivity
If higher device density is pursued, then performance improves, but fabrication control difficulty increases
Solution Approach 1:
The epitaxial growth process self-aligns to form fins with precise geometry controlled by the mask pattern, reducing the need for additional alignment steps. The conformal gate dielectric deposition automatically follows the fin contours, ensuring uniform thickness and precise gate alignment across high-density structures.
Solution Approach 2:
The method controls fin dimensions and gate characteristics by adjusting epitaxial growth parameters (temperature, pressure, gas flow rates) and deposition parameters, enabling precise control of fin geometry and gate structure to achieve high device density while maintaining fabrication control.
3Reliability
If replacement gate process is used, then electrical performance improves, but manufacturing steps increase
Solution Approach 1:
A dummy gate structure is formed preliminarily during the initial patterning stage to guide subsequent processing steps. The actual metal gate is then deposited and formed in a replacement step, allowing precise gate alignment and electrical performance optimization while integrating into the overall fabrication flow.
Solution Approach 2:
The dummy gate structure serves as an intermediary element that facilitates precise alignment and processing during fabrication. It is temporarily formed to guide subsequent steps, then replaced by the final metal gate structure, enabling complex gate formation while managing process complexity through a systematic intermediary approach.
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 method enhances the electrical performance and density of semiconductor devices by allowing precise control over fin and gate structures, reducing short channel effects and improving metal gate filling, thereby increasing device performance and efficiency.
Implementation Method 1
forming semiconductor fins on a substrate, using epitaxial growth and patterning techniques
Data Source
AI summary
A semiconductor device includes a substrate, at least one active region, at least one gate structure, and an insulating structure. The active region is present at least partially in the substrate. The gate structure is present on the active region. The gate structure has at least one end sidewall and a top surface intersecting to form a top interior angle. The top interior angle is an acute angle. The insulating structure is present adjacent to the end sidewall of the gate structure and on the substrate.