Hydrophobic Coating Prevents Pattern Collapse During Semiconductor Drying
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Solution Overview
Problem
In semiconductor manufacturing, the miniaturization of critical dimensions leads to resist pattern collapse due to capillary phenomena during the drying process after lithography, and existing methods such as hydrophobic surface treatments and supercritical CO2 drying face challenges in preventing pattern collapse, especially in mass production and maintaining cleanliness.
Innovation Solution
A method involving the formation of a hydrophobic functional surface on semiconductor substrates through chemical treatments, followed by rinsing and drying, which reduces the surface tension's impact on pattern collapse by increasing the contact angle, thereby preventing pattern collapse during drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydrophobic surface treatment is applied to resist patterns to reduce capillary force, then pattern collapse is prevented, but the organic material is removed together with the resist pattern in subsequent dry etching processes
Solution Approach 1:
The patent uses a silane-based hydrophobic material as an intermediary substance that forms a protective coating on the resist pattern surface. This intermediary layer reduces capillary force during drying while being designed to withstand subsequent dry etching processes, thus preventing both pattern collapse and organic material loss.
Solution Approach 2:
The hydrophobic surface treatment is applied in advance before the dry etching process. By preliminarily forming the hydrophobic coating on the resist pattern, the patent ensures that the pattern is protected from capillary collapse during drying, and the coating remains intact through the subsequent etching process.
2Manufacturing precision
If IPA is used to substitute pure water on the wafer during drying treatment, then the wafer is dried, but the pattern formed on the wafer collapses due to surface tension of the solution
Solution Approach 1:
The patent changes the surface energy parameters of the resist pattern by applying a hydrophobic coating. This parameter change increases the contact angle of drying solutions, reducing capillary force and preventing pattern collapse while maintaining effective drying.
3Reliability
If supercritical CO2 drying is used to eliminate surface tension, then pattern collapse is prevented, but the method is difficult to apply to mass production and cannot prevent collapse when water content enters the chamber
Solution Approach 1:
The patent employs a silane-based hydrophobic coating that can be applied using conventional semiconductor manufacturing equipment. This disposable-like coating is applied to each wafer, provides immediate protection against capillary collapse, and can be removed or degraded after serving its protective function, enabling mass production compatibility.
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 method effectively prevents pattern collapse during drying treatments, especially for high-aspect-ratio patterns, while maintaining the cleanliness of the substrate surface, even in mass production settings.
Implementation Method 1
forming a hydrophobic functional surface on the modified surface of the convex patterns
Implementation Method 2
the miniaturization of critical dimensions leads to resist pattern collapse due to capillary phenomena upon developing and drying the resist pattern
Implementation Method 3
cleaning and modifying a surface of the convex patterns by using chemical
Implementation Method 4
drying the semiconductor substrate
Data Source
AI summary
A method of treating a semiconductor substrate has forming convex patterns over the semiconductor substrate by dry etching, cleaning and modifying a surface of the convex patterns by using chemical, forming a hydrophobic functional surface on the modified surface of the convex patterns, after forming the hydrophobic functional surface, rinsing the semiconductor substrate by using water, drying the semiconductor substrate, and removing the hydrophobic functional group from the hydrophobic functional surface of the convex patterns.