Spin-Coat Planarization Model for 3D Substrate Topography
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Solution Overview
Problem
Current technologies lack the ability to effectively predict and address non-uniformity in spin-on coatings on substrates with complex topography, leading to challenges in achieving planarization during micro- and nano-scale device fabrication, especially as devices transition to three-dimensional structures.
Innovation Solution
A method is developed to calibrate a film thickness model over patterned topography, predicting film thickness outcomes and recommending adjustments in materials, application processes, or hardware solutions to enhance planarization, including mechanical and chemical smoothing, and redesigning feature topographies, which can be integrated into electronic design automation for process corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If spin coating is performed on substrates with complex topography, then film coverage is achieved, but film uniformity and planarization deteriorate
Solution Approach 1:
The system performs preliminary characterization of substrate topography using optical or physical profilometry before spin coating. This advance knowledge allows the system to predict film thickness distribution and adjust processing parameters beforehand, ensuring uniform film formation on complex topographies while maintaining good coverage
Solution Approach 2:
The system modifies spin coating parameters (speed, acceleration, coating amount) based on measured substrate topography characteristics. By dynamically adjusting these parameters according to the specific topography, the system achieves both complete coverage and uniform film thickness even on complex 3D structures
2Productivity
If scaling efforts increase transistor density in 2D circuits, then number of transistors per unit area improves, but device fabrication complexity increases
Solution Approach 1:
The system implements self-service through automated feedback loops where film thickness measurements automatically trigger process adjustments. The system characterizes its own output and corrects deviations without external intervention, managing fabrication complexity through autonomous control while enabling high transistor density
Solution Approach 2:
The system employs real-time feedback by measuring film thickness after spin coating and using this information to adjust subsequent processing steps. This closed-loop control handles the increased fabrication complexity by automatically compensating for variations, enabling continued scaling of transistor density
3Adaptability or versatility
If devices transition to three-dimensional structures, then device functionality improves, but film planarization becomes more difficult
Solution Approach 1:
The system performs preliminary topography measurement and film thickness prediction before spin coating on 3D structures. This advance characterization allows optimization of coating parameters specifically for the measured topography, achieving planarization on complex three-dimensional device structures
Solution Approach 2:
The system dynamically adjusts spin coating parameters based on the specific three-dimensional topography characteristics. By modifying coating amount, spin speed, and acceleration profiles according to measured topography, the system achieves uniform film formation and planarization on vertically structured devices
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 enables precise control of film thickness across multiple length scales, improving product yield by correcting deviations in downstream processes and ensuring stringent film thickness control, particularly in 3D applications like finfets and through silicon vias.
Implementation Method 1
The substrate is then rotated at high speed in order to spread the coating material by centrifugal force
Implementation Method 2
The applied solvent is usually volatile, and simultaneously evaporates
Data Source
AI summary
Described herein are technologies to facilitate device fabrication, especially those that involve spin-on coatings of a substrate (e.g., wafer). More particularly, technologies described herein facilitate the planarization (i.e., flatness) of spin-on coatings during the device fabrication to form a uniformly planar film or layer on the substrate. This abstract itself is not intended to limit the scope of this patent. The scope of the present invention is pointed out in the appending claims.