Semiconductor Fin Air Spacer Structure for Lower Capacitance
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Solution Overview
Problem
The challenge in semiconductor manufacturing is forming reliable devices at smaller sizes due to increased complexity and difficulty in fabrication processes as feature sizes decrease, leading to higher capacitance and RC delay.
Innovation Solution
The use of air spacers surrounding semiconductor features in integrated circuits to reduce overall capacitance by employing a dielectric constant of 1, thereby improving device performance and reducing RC delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes are decreased to increase functional density, then production efficiency is improved and costs are lowered, but fabrication complexity and difficulty increase
Solution Approach 1:
The patent introduces a sacrificial layer as an intermediary component that facilitates the formation of air gaps between adjacent fins. This sacrificial layer is deposited conformally and then selectively removed to create the desired air gap structure, thereby simplifying the overall fabrication process while enabling reduced feature sizes and improved functional density
2Productivity
If feature sizes are decreased to increase functional density, then production efficiency is improved and costs are lowered, but manufacturing reliability deteriorates
Solution Approach 1:
The sacrificial layer serves as a temporary mediator that enables precise control over air gap formation. By using this intermediary structure, the manufacturing process achieves better reliability in creating consistent, small-featured devices with controlled dimensions, while maintaining high production efficiency through standardized deposition and removal steps
3Strength
If conventional dielectric materials are used between fins, then structural support is provided, but capacitance and RC delay increase
Solution Approach 1:
The patent extracts the dielectric material from between adjacent fins by using a sacrificial layer removal process. This creates air gaps (vacuum or air-filled spaces) between the fins, eliminating the parasitic capacitance that would otherwise be present with conventional dielectric materials, while the fins maintain their structural integrity through the fabrication process design
Solution Approach 2:
The patent creates a porous structure with air gaps between fins by removing the sacrificial layer. These air-filled porous regions provide electrical isolation between adjacent fins with minimal parasitic capacitance, thereby reducing RC delay while maintaining the necessary structural support through the overall device architecture
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 implementation of air spacers effectively lowers the overall capacitance of integrated circuits, enhancing device performance by minimizing RC delay and improving manufacturing reliability.
Implementation Method 1
The use of air spacers surrounding semiconductor features in integrated circuits to reduce overall capacitance by employing a dielectric constant of 1
Data Source
AI summary
A semiconductor device includes a substrate, a semiconductor fin, a shallow trench isolation (STI) structure, an air spacer, and a gate structure. The semiconductor fin extends upwardly from the substrate. The STI structure laterally surrounds a lower portion of the semiconductor fin. The air spacer is interposed the STI structure and the semiconductor fin. The gate structure extends across the semiconductor fin.