Confined Air Gap Interconnects for Parasitic Capacitance Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration density of electronic components in semiconductor devices is limited by increasing parasitic capacitance due to reduced feature sizes, which leads to higher power consumption and RC time delays, and current low-k dielectric materials face processing challenges that hinder further improvement.
Innovation Solution
The method involves forming air gaps using chemical vapor deposition and a series of processing steps, including patterning, deposition, and etching, to create a semiconductor structure with controlled air gaps that reduce parasitic capacitance by using dielectric spacers and sacrificial features to define trenches and form air gaps, allowing for precise control of air gap height and width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If feature sizes are reduced to improve integration density, then integration density is improved, but parasitic capacitance between metal features increases
Solution Approach 1:
The patent extracts the dielectric material between metal features and replaces it with air gaps. By removing the solid dielectric material and creating void spaces filled with air (k=1), the parasitic capacitance between adjacent metal features is significantly reduced while maintaining the miniaturized feature sizes needed for high integration density
Solution Approach 2:
The patent introduces porous air gap structures between metal features. These air gaps are created by forming sacrificial mandrels and then removing them, leaving controlled porous spaces that reduce dielectric constant and parasitic capacitance while allowing the metal features to remain closely spaced for high integration density
2Object-generated harmful factors
If low-k dielectric materials are used to reduce parasitic capacitance, then parasitic capacitance is reduced, but processing problems increase
Solution Approach 1:
The patent uses sacrificial mandrels made of temporary materials that are deposited, patterned, and then completely removed to create air gaps. These disposable mandrels simplify the manufacturing process compared to low-k materials, as they can be easily deposited using standard CVD techniques and removed through selective etching or burn-off, avoiding the complex processing issues associated with low-k dielectric materials
Solution Approach 2:
The patent changes the dielectric constant parameter by replacing solid dielectric materials with air (k=1). This fundamental parameter change achieves lower parasitic capacitance without the processing complexity of low-k materials, as air gaps can be created using standard semiconductor fabrication techniques without requiring specialized low-k material deposition and handling processes
3Object-generated harmful factors
If air gaps are introduced to reduce parasitic capacitance, then parasitic capacitance is reduced, but manufacturing complexity increases
Solution Approach 1:
The patent performs preliminary actions by depositing sacrificial mandrels and forming preliminary structures before creating the final air gaps. The mandrels are deposited conformally, patterned, and used as templates to define the air gap locations, simplifying the overall process by establishing a clear sequence of operations that integrates well with existing fabrication workflows
Solution Approach 2:
The patent uses sacrificial mandrels as intermediary structures that facilitate air gap creation. These temporary mandrels serve as mediators between the deposition process and the final air gap structure, allowing standard CVD equipment to create precise air gaps without requiring direct air introduction or complex vacuum processes
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 effectively reduces parasitic capacitance and enhances RC performance by creating well-controlled air gaps that improve isolation between metal features, thereby reducing power consumption and RC time delays.
Implementation Method 1
chemical vapor deposition
Data Source
AI summary
A method for manufacturing a semiconductor structure includes forming a plurality of dummy structures spaced apart from each other, forming a plurality of dielectric spacers laterally covering the dummy structures to form a plurality of trenches defined by the dielectric spacers, filling a conductive material into the trenches to form electrically conductive features, selectively depositing a capping material on the electrically conductive features to form a capping layer, removing the dummy structures to form a plurality of recesses defined by the dielectric spacers, filling a sacrificial material into the recesses so as to form sacrificial features, depositing a sustaining layer on the sacrificial features, and removing the sacrificial features to form air gaps confined by the sustaining layer and the dielectric spacers.