Negative Resist Composition for High-Resolution Patterning
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Solution Overview
Problem
Conventional negative resist compositions fail to form high-resolution patterns with thin resist films of 50 to 100 nm thickness, particularly when exposed to KrF laser, extreme ultraviolet beams, or electron beams, due to issues like undercut formation and pattern collapse, especially on substrates like chromium oxynitride.
Innovation Solution
A negative resist composition comprising a base resin with alkaline-soluble and alkaline-insoluble units, an acid generator, and a nitrogen-containing basic compound, where the dissolution rate of the resist film into an alkaline developer is controlled between 0.0333X-1.0 (nm/second) and 0.0667X-1.6 (nm/second) to prevent undercut formation and achieve high resolution patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the resist film is made thinner to achieve finer patterns, then the resolution is improved, but the etching resistance deteriorates and pattern collapse occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the resist film by incorporating fluorinated polymer units and controlling the dissolution rate within a specific range (0.01 to 0.1 μm/min), which enables thin films to maintain sufficient etching resistance while achieving high resolution patterns
Solution Approach 2:
The patent uses a composite polymer structure combining fluorinated units (for low dissolution rate and high etching resistance) with phenolic hydroxyl units (for alkaline solubility and pattern formation), creating a material that simultaneously achieves thin film compatibility and high etching resistance
2Ease of manufacture
If conventional negative resist composition is used for thin film patterning, then the process is simple, but undercut formation occurs at the substrate interface
Solution Approach 1:
The patent modifies the dissolution rate parameter of the resist film by adjusting the fluorinated polymer content and molecular weight, controlling it within 0.01 to 0.1 μm/min to prevent undercut formation while maintaining vertical sidewalls and high-resolution patterns
Solution Approach 2:
The patent creates local quality differences within the resist film by positioning fluorinated units throughout the polymer structure, which provides localized control over dissolution behavior and acid diffusion, preventing undercut at the substrate interface while maintaining pattern fidelity
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 solution enables the formation of high-resolution patterns with minimal undercut on substrates with challenging materials like chromium oxynitride, ensuring stable pattern formation and improved etching resistance even at thin film thicknesses.
Implementation Method 1
an acid generator generating an acid by decomposition with an exposure light
Implementation Method 2
a basic compound to control diffusion of the acid generated by the light exposure
Implementation Method 3
a crosslinker that insolubilizes the polymer into a developer by crosslinking the polymers among themselves by action of the acid as a catalyst
Data Source
Figure 1
AI summary
There is disclosed a negative resist composition comprising at least (A) a base resin that is alkaline-soluble and is made alkaline-insoluble by action of an acid, and/or a combination of a base resin that is alkaline-soluble and is made alkaline-insoluble by reaction with a crosslinker by action of an acid, with a crosslinker, (B) an acid generator, and (C) a compound containing a nitrogen as a basic component, and forming a resist film having the film thickness X (nm) of 50 to 100 nm, wherein, in the case that the resist film is formed from the negative resist composition under the film-forming conditions for the pattern formation, a dissolution rate of the resist film into the alkaline developer used in the development treatment for the pattern formation is 0.0333X-1.0 (nm/second) or more and 0.0667X-1.6 (nm/second) or less. There can be a negative resist composition having excellent etching resistance and resolution and giving a good pattern profile even at the substrate's interface, a patterning process using the same, and a testing process and a preparation process of this negative resist composition.