Flowable Dielectric Deposition for Void-Free Gate Gap Filling
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Solution Overview
Problem
The scaling down of semiconductor integrated circuits has increased the complexity of processing and manufacturing, particularly in filling high aspect ratio gaps between device features, leading to voids and seams in insulating materials, which affect device performance and wafer acceptance testing.
Innovation Solution
A flowable chemical vapor deposition (FCVD) process is employed to form high-quality interlayer dielectric layers, involving ultraviolet curing and low-temperature annealing to fill high aspect ratio gaps between gate structures, followed by planarization to optimize gap filling and reduce void formation, while maintaining electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition processes are used to fill high aspect ratio gaps, then the gaps can be filled with insulating material, but voids and seams form in the deposited material
Solution Approach 1:
The patent changes the physical and chemical parameters of the deposition process by using flowable dielectric material with specific viscosity characteristics and controlling deposition temperature and pressure parameters to enable void-free filling of high aspect ratio gaps
Solution Approach 2:
The patent employs composite processing combining flowable chemical vapor deposition with subsequent ultraviolet curing and annealing treatments to transform the flowable material into a solid dielectric layer without voids or seams
2Manufacturing precision
If high temperature annealing is used to process the dielectric layer, then the material properties improve, but oxygen and germanium diffusion increases
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperature annealing to low temperature annealing (below 500°C), and compensates by adjusting UV curing power (greater than 80%) to achieve the desired dielectric layer quality without causing harmful diffusion
Solution Approach 2:
The patent substitutes thermal processing with ultraviolet curing as the primary mechanism to solidify and densify the dielectric material, replacing the need for high temperature thermal annealing that causes diffusion
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 FCVD process effectively fills high aspect ratio gaps with minimal voids, improving device performance and wafer acceptance testing by reducing oxygen and germanium diffusion, thereby enhancing the reliability and efficiency of semiconductor manufacturing.
Implementation Method 1
A flowable chemical vapor deposition (FCVD) process is employed to form high-quality interlayer dielectric layers
Implementation Method 2
involving ultraviolet curing and low-temperature annealing to fill high aspect ratio gaps between gate structures
Implementation Method 3
annealing the ultraviolet cured, flowable dielectric material
Data Source
AI summary
An exemplary flowable chemical vapor deposition method includes depositing a flowable dielectric material over a substrate, ultraviolet curing the flowable dielectric material, and annealing the ultraviolet cured, flowable dielectric material. The flowable dielectric material fills a space between a first gate structure and a second gate structure. An ultraviolet power of the ultraviolet curing is greater than about 80%, and an annealing temperature of the annealing is less than about 500° C. A thickness of the flowable dielectric material deposited over tops of the first gate structure and the second gate structure is less than about 200 nm. The ultraviolet power, the temperature, and an as-deposited thickness may be selected based on germanium pile up characteristics expected at an inner spacer/source/drain interface.