Semiconductor Pattern Coating for High-Aspect-Ratio Collapse Prevention
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Solution Overview
Problem
Fine patterns in semiconductor manufacturing with high aspect ratios experience collapse during cleaning processes due to surface tension forces, which conventional methods like using alcohols or surfactants cannot effectively mitigate, especially as aspect ratios increase.
Innovation Solution
A coating composition comprising an amide compound and a phosphorus compound forms a self-assembly monolayer on the pattern interface, adjusting the contact angle of water to 80° to 100°, thereby reducing the capillary force and preventing pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the aspect ratio of patterns is increased to achieve finer patterns and higher integration density, then manufacturing precision and integration density are improved, but pattern collapse occurs during cleaning processes
Solution Approach 1:
The patent applies preliminary action by forming a coating layer on the pattern surface before the cleaning process. This coating layer, created through spin-coating or dip-coating methods, pre-establishes a protective barrier that prevents capillary forces during subsequent cleaning from causing pattern collapse. The coating is applied in advance to modify the surface properties before the harmful cleaning step occurs.
Solution Approach 2:
The patent introduces an intermediary substance (coating material) between the pattern and the cleaning liquid. This coating layer acts as a mediator that interacts with the cleaning liquid to reduce surface tension effects and capillary forces. The coating material serves as a buffer interface that protects the underlying high aspect ratio pattern from direct exposure to destabilizing forces during cleaning.
2Ease of manufacture
If conventional cleaning methods using distilled water or low surface tension agents like alcohols are used, then cleaning effectiveness is maintained, but they fail to prevent pattern collapse in high aspect ratio patterns
Solution Approach 1:
The patent applies parameter changes by modifying the surface energy characteristics of the pattern through coating application. Rather than changing the cleaning liquid parameters, the invention changes the pattern surface parameters by adding a coating layer with specific surface tension properties. This coating modifies the contact angle and surface energy to reduce capillary forces while maintaining cleaning effectiveness.
Solution Approach 2:
The patent uses composite materials by combining the pattern material with a coating material to create a composite structure. This composite consists of the original pattern (polysilicon, silicon oxide, silicon nitride, or metal) combined with a coating layer that has complementary properties for reducing surface tension effects. The composite structure leverages the strengths of both materials to achieve both pattern stability and cleaning effectiveness.
3Force
If the contact angle between water and pattern is not optimized, then cleaning liquid drainage during spin-drying creates high capillary forces, but optimizing the contact angle to close to 90° requires specialized coating materials and processes
Solution Approach 1:
The patent systematically changes the contact angle parameter to optimize it close to 90 degrees. By selecting coating materials with appropriate surface energy characteristics and controlling coating thickness, the invention achieves a contact angle that minimizes capillary forces during spin-drying. This parameter optimization balances the complexity of the coating process with the benefit of reduced pattern collapse.
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 coating composition enables uniform coating and prevents pattern collapse during drying, enhancing yield and reducing manufacturing costs and time by minimizing defects in memory semiconductor devices.
Implementation Method 1
a self-assembly monolayer (SAM) is formed on an interface of a pattern by mixing the coating composition with an organic solvent
Implementation Method 2
The force that causes a fine pattern formed on a substrate to collapse increases in proportion to the surface tension of a material used during the patterning process
Implementation Method 3
The force that causes a fine pattern formed on a substrate to collapse increases in proportion to the surface tension of a material used during the patterning process, as well as cleaning, with respect to the fine pattern and to the cosine θ (cosθ) value of the contact angle
Data Source
Figure 1~2
AI summary
The objective of the present invention is to provide a coating composition capable of preventing pattern collapse by causing the contact angle between a semiconductor device pattern and water to be close to 90°, and to provide a pattern coated with the coating composition, and the coating composition capable of preventing pattern collapse comprises: a coating material for preventing pattern collapse, comprising an amide compound represented by chemical formula (1) or a phosphorus compound represented by chemical formula (2); and an organic solvent.