Stimulus-Responsive Polymer Coatings for Feature Collapse Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor fabrication faces challenges due to airborne molecular contaminants and capillary forces during drying processes, leading to feature collapse and stiction in high aspect ratio structures, which degrade device yield and are costly to mitigate.
Innovation Solution
The use of stimulus-responsive polymers (SRPs) with a ceiling temperature between -80°C and 400°C, combined with organic weak acids, to form protective layers on semiconductor substrates. These layers can be degraded by exposure to stimuli such as light, heat, or chemistry, allowing for the removal of volatile monomers and fragments, thus protecting sensitive surfaces and preventing feature collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional wet processes are used for high aspect ratio structures, then material removal and cleaning are achieved, but capillary forces during drying cause feature collapse and stiction
Solution Approach 1:
A sacrificial polymer layer is deposited as an intermediary substance within the high aspect ratio features. This layer acts as a temporary mediator that prevents capillary forces from acting directly on the features during drying. After the wet process is complete, the polymer is removed through thermal decomposition or chemical etching, leaving the features intact without collapse or stiction.
Solution Approach 2:
The sacrificial polymer layer is applied beforehand to cushion and protect the high aspect ratio features from the harmful capillary forces that will occur during subsequent drying. This pre-positioned protective layer absorbs the mechanical stress of drying, preventing feature collapse before it can occur.
2Object-affected harmful factors
If nitrogen-filled storage cassettes or rooms are used to protect substrates from airborne molecular contaminants, then substrate protection is improved, but implementation complexity and cost increase
Solution Approach 1:
A thin, disposable sacrificial polymer coating is applied to the substrate surface to provide temporary protection against airborne molecular contaminants during queue time. This single-use protective layer is much simpler and cheaper than implementing nitrogen-filled storage infrastructure, and can be removed easily when no longer needed.
Solution Approach 2:
The protective function is achieved by changing the surface chemistry of the substrate through polymer deposition, rather than changing the environmental parameters (such as implementing nitrogen atmosphere). This parameter change at the material level provides protection without requiring complex environmental control systems.
3Object-affected harmful factors
If vacuum environments are maintained in integrated tools to prevent AMC exposure, then substrate protection is improved, but tool complexity and processing flexibility deteriorate
Solution Approach 1:
A disposable sacrificial polymer layer provides temporary protection against oxidation and corrosion during queue time, eliminating the need to maintain vacuum environments in integrated tools. This simple material-based solution replaces complex vacuum system requirements while allowing full processing flexibility.
Solution Approach 2:
The protective polymer layer is applied in advance before the substrate is exposed to ambient conditions. This preliminary protective action prevents oxidation and corrosion from occurring, allowing the substrate to be processed in ambient air without requiring vacuum environments in the tooling.
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 SRP layers provide accelerated degradation characteristics compared to neat SRP, effectively protecting sensitive substrates from environmental contaminants and capillary forces, thereby enhancing device yield and reducing processing costs.
Implementation Method 1
the SRP characterized by a ceiling temperature (Tc) at which the SRP is in thermal equilibrium with its monomers
Implementation Method 2
Formulations for forming stimulus responsive polymers (SRPs) on semiconductor substrates including organic weak acids are described. SRP layers formed from the formulations exhibit accelerated degradation characteristics compared to neat SRP.
Implementation Method 3
In some embodiments, the one or more cap layers are removed by peeling.
Implementation Method 4
In some embodiments, the one or more cap layers are removed by exposure to a solvent or plasma.
Implementation Method 5
In some embodiments, the one or more cap layers are removed by exposure to a solvent or plasma.
Data Source
AI summary
Formulations for forming stimulus responsive polymers (SRPs) on semiconductor substrates include organic weak acids. Methods of protecting sensitive substrates including forming an SRP layer on sensitive substrates and forming one or more cap layers on the SRP layer.