Flowable Low-k Dielectric Gapfill via Ammonia Treatment
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Solution Overview
Problem
Conventional chemical vapor deposition techniques face challenges in filling tall, narrow gaps between semiconductor circuit elements with low-k dielectric materials, often resulting in voids or weak seams due to overgrowth and material sticking issues, which are difficult to address effectively.
Innovation Solution
The development of flowable CVD techniques using silicon-and-carbon containing precursors combined with radical-oxygen precursors in a remote plasma region, followed by treatment with hydrogen-and-nitrogen-containing precursors like ammonia, to form a silicon-carbon-oxygen layer that reduces shrinkage and enhances filling capabilities of low-k dielectric films in narrow trenches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CVD techniques are used to fill tall, narrow gaps, then dielectric material can be deposited, but the material gets stuck and creates voids or weak seams due to overgrowth at the top of the gap
Solution Approach 1:
The patent changes the physical and chemical parameters of the dielectric material by incorporating organic precursors (silicon-and-carbon-containing precursors) to create a flowable low-k dielectric material. This parameter change enables the material to flow into high-aspect-ratio gaps without sticking, preventing voids and weak seams while maintaining film continuity.
Solution Approach 2:
The patent uses composite material composition by combining silicon precursors, carbon precursors, and oxygen precursors to form a silicon-carbon-oxygen (SiCO) flowable dielectric material. This composite approach provides both the flowability needed to fill tall narrow gaps and the dielectric properties required for electrical isolation.
2Productivity
If the gap width between circuit elements is reduced to achieve miniaturization, then device density increases, but the gap becomes taller and narrower making it difficult to fill without creating voids
Solution Approach 1:
The patent modifies the material parameters by using flowable precursors with appropriate viscosity and reactivity characteristics. The silicon-and-carbon-containing precursors create a material that can flow into high-aspect-ratio gaps (tall and narrow) formed by miniaturized circuit elements, ensuring complete filling without voids even as device density increases.
3Reliability
If flowable CVD techniques are used to fill high-aspect-ratio gaps, then void formation is reduced, but shrinkage occurs during subsequent processing
Solution Approach 1:
The patent applies a treatment with hydrogen-and-nitrogen-containing precursor (such as ammonia) before curing to preliminarily stabilize the SiCO film structure. This preliminary action reduces subsequent shrinkage during processing while maintaining the complete gap filling achieved by the flowable deposition technique.
Solution Approach 2:
The patent changes the chemical composition parameters of the dielectric film by incorporating hydrogen and nitrogen from the treatment precursor. This compositional modification enhances the film's dimensional stability and reduces shrinkage during subsequent processing steps.
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 effectively reduces shrinkage and improves the physical stability of low-k dielectric films, minimizing electrical cross-talk and increasing production yield by enabling seamless filling of high-aspect ratio gaps with low-k dielectric materials.
Implementation Method 1
flowing an oxygen-containing precursor into a remote plasma region while igniting a remote plasma to form a radical-oxygen precursor
Implementation Method 2
combining the silicon-and-carbon-containing precursor and the radical-oxygen precursor in the substrate processing region to form a low-k dielectric film on the patterned substrate
Implementation Method 3
The treatment may remove residual moisture from the silicon-carbon-oxygen layer and may make the lattice more resilient during curing and subsequent processing
Implementation Method 4
exposing the silicon-carbon-oxygen film to at least one of UV-light or an electron beam after exposing the silicon-carbon-oxygen film to the atmosphere comprising the hydrogen-and-nitrogen-containing precursor
Data Source
AI summary
Methods are described for forming a flowable low-k dielectric film on a patterned substrate. The film may be a silicon-carbon-oxygen (Si—C—O) layer in which the silicon and carbon constituents come from a silicon and carbon containing precursor while the oxygen may come from an oxygen-containing precursor activated in a remote plasma region. Shortly after deposition, the silicon-carbon-oxygen layer is treated by exposure to a hydrogen-and-nitrogen-containing precursor such as ammonia prior to curing. The treatment may remove residual moisture from the silicon-carbon-oxygen layer and may make the lattice more resilient during curing and subsequent processing. The treatment may reduce shrinkage of the silicon-carbon-oxygen layer during subsequent processing.