Low-k Dielectric Films via Cyclic Silicon Precursors
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Solution Overview
Problem
Conventional silica-based dielectric films with lower dielectric constants suffer from reduced mechanical strength, leading to defects such as delamination, buckling, and electromigration, and increased carbon depletion issues, which affect the reliability and integration of electronic devices.
Innovation Solution
The use of alkoxysilacyclic or acyloxysilacyclic compounds like 1,1-dimethoxysilacyclopentane as silicon precursors in chemical vapor deposition methods to form low-k dielectric films with higher carbon content, which can be further treated with thermal, plasma, or UV energy to enhance mechanical strength without compromising the dielectric constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If carbon content of organosilica glass is increased to reduce dielectric constant, then dielectric constant is reduced, but mechanical strength decreases rapidly
Solution Approach 1:
The patent changes the chemical parameters of the precursor molecule by introducing a cyclic structure with specific Si-O-Si bond angles and incorporating carbon-containing groups. This parameter change allows the film to achieve lower dielectric constant (k ≤ 3.2) while maintaining mechanical strength through the unique cyclic precursor architecture that controls carbon distribution and network connectivity.
Solution Approach 2:
The patent creates a composite organosilica glass material combining silicon oxide network with organic carbon-containing groups from the cyclic precursor. This composite structure achieves low dielectric constant through carbon incorporation while the silicon oxide framework maintains mechanical integrity, resolving the contradiction between electrical and mechanical properties.
2Ease of manufacture
If conventional silica CVD dielectric films are produced from SiH4 or TEOS, then films are deposited, but dielectric constant is greater than 4.0
Solution Approach 1:
The patent changes the precursor material from conventional SiH4 or TEOS to a cyclic organosilica precursor containing carbon groups. This parameter change in the precursor chemistry enables the deposition process to produce films with dielectric constant ≤ 3.2 while maintaining CVD manufacturing compatibility, thus resolving the contradiction between ease of manufacture and dielectric constant requirement.
3Quantity of substance
If bridged precursors with two silicon groups are used to increase carbon content, then carbon content increases, but boiling point increases making delivery difficult
Solution Approach 1:
The patent optimizes the molecular weight and structural parameters of the cyclic precursor to achieve a balance between carbon content and volatility. The cyclic structure with specific ring size and carbon group configuration provides sufficient carbon content for low dielectric constant while maintaining a boiling point suitable for CVD delivery, resolving the contradiction between carbon content and ease of operation.
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 approach results in low-k dielectric films with improved mechanical properties, increased carbon content, and enhanced integration capabilities, reducing defects and maintaining a dielectric constant of 2.3 to 3.2, while being more convenient to process due to lower molecular weight and boiling points compared to traditional precursors.
Implementation Method 1
a chemical vapor deposition method for producing a dielectric film, comprising: providing a substrate into a reaction chamber; introducing gaseous reagents into the reaction chamber wherein the gaseous reagents comprise a silicon precursor comprising an silicon compound
Implementation Method 2
applying energy to the gaseous reagents in the reaction chamber to induce reaction of the gaseous reagents to deposit a film on the substrate
Implementation Method 3
The film as deposited can be subsequently treated with thermal, plasma or UV energy sources to change the film properties to for example provide chemical crosslinking to enhance mechanical strength
Implementation Method 4
The film as deposited can be subsequently treated with thermal, plasma or UV energy sources to change the film properties to for example provide chemical crosslinking to enhance mechanical strength
Data Source
AI summary
A chemical vapor deposition method for producing a dielectric film, the method comprising: providing a substrate into a reaction chamber; introducing gaseous reagents into the reaction chamber wherein the gaseous reagents comprise a silicon precursor comprising an silicon compound having Formula I as defined herein and applying energy to the gaseous reagents in the reaction chamber to induce reaction of the gaseous reagents to deposit a film on the substrate. The film as deposited is suitable for its intended use without an optional additional cure step applied to the as-deposited film.