Air Spacer and Cap Structures for Semiconductor Parasitic Capacitance Reduction
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Solution Overview
Problem
The scaling down of semiconductor devices has resulted in smaller electrical isolation regions, leading to inadequate reduction of parasitic capacitance and increased current leakage between gate structures and source/drain contact structures, as well as between gate structures and interconnect structures, which negatively impacts device reliability and performance.
Innovation Solution
The implementation of air spacers and air caps with low dielectric constant materials between the sidewalls of gate structures and source/drain contact structures, and between conductive interconnect structures and gate structures, providing improved electrical isolation and reducing parasitic capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device dimensions are scaled down to increase storage capacity and processing speed, then productivity and performance are improved, but electrical isolation regions become smaller leading to increased parasitic capacitance and current leakage
Solution Approach 1:
The patent introduces air spacers and air caps as intermediary structures between conductive elements (gate structures, source/drain contact structures, and interconnect structures). These air-filled spaces act as mediators that provide electrical isolation with significantly lower parasitic capacitance compared to traditional dielectric materials, thereby resolving the contradiction between miniaturization and electrical isolation effectiveness.
Solution Approach 2:
The patent changes the dielectric parameter by replacing conventional dielectric materials with air-filled spaces. Air has a dielectric constant of approximately 1.0, which is significantly lower than traditional dielectric materials, thereby reducing parasitic capacitance and improving electrical isolation in scaled-down device configurations.
2Quantity of substance
If electrical isolation regions are reduced in size to enable further scaling, then device density is improved, but parasitic capacitance reduction becomes inadequate and current leakage increases
Solution Approach 1:
Air spacers and air caps serve as intermediary structures that maintain effective electrical isolation even when isolation region dimensions are reduced. The air-filled spaces provide a low-capacitance pathway that prevents harmful parasitic effects while allowing for higher device density through further scaling.
Solution Approach 2:
By changing the dielectric parameter from conventional materials to air (dielectric constant ≈1.0), the patent achieves superior parasitic capacitance reduction in smaller isolation regions, enabling higher device density without suffering from increased parasitic effects or current leakage.
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 reduces parasitic capacitance by 20% to 50% and minimizes current leakage, thereby enhancing the reliability and performance of semiconductor devices.
Implementation Method 1
air spacers and air caps with low dielectric constant materials between the sidewalls of gate structures and source/drain contact structures
Data Source
AI summary
A semiconductor device with air spacers and air caps and a method of fabricating the same are disclosed. The semiconductor device includes a substrate and a fin structure disposed on the substrate. The fin structure includes a first fin portion and a second fin portion. The semiconductor device further includes a source/drain (S/D) region disposed on the first fin portion, a contact structure disposed on the S/D region, a gate structure disposed on the second fin portion, an air spacer disposed between a sidewall of the gate structure and the contact structure, a cap seal disposed on the gate structure, and an air cap disposed between a top surface of the gate structure and the cap seal.