Low-Sulfur Naphthol Novolak Resin for Semiconductor Pattern Stability
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Solution Overview
Problem
Current techniques for forming organic films as hard masks in semiconductor manufacturing face challenges in achieving high pattern-curving resistance and preventing line collapse and twisting, especially for high-aspect line patterns finer than 40 nm, due to insufficient planarization and twisting resistance.
Innovation Solution
A composition comprising a condensate of dihydroxynaphthalene and a condensation agent, with a sulfur content of 100 ppm or less, is used to form an organic film that provides high filterability and resistance to pattern-curving, preventing line collapse and twisting after dry etching through precise filtration and crosslinking reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an organic underlayer film is formed by spin coating to fill steps and planarize the substrate, then the substrate surface can be planarized and depth of focus in lithography increases, but the anti-twisting property is insufficient compared to CVD-C film
Solution Approach 1:
The patent uses a composite organic resin system combining a naphthol novolak resin (providing planarization and filling properties) with a phenolic resin or resinoid (providing anti-twisting property). This composite material approach allows the organic underlayer film to simultaneously achieve both planarization quality and anti-twisting resistance that were previously conflicting requirements.
2Reliability
If a CVD-C film is used as underlayer film, then the anti-twisting property is excellent, but the film cannot fill steps effectively to achieve planarization on stepped substrates
Solution Approach 1:
The patent creates a composite organic resin system where the naphthol novolak resin component provides excellent filling and planarization capabilities on stepped substrates, while the phenolic resin or resinoid component contributes anti-twisting properties. This composite approach replaces the CVD-C film's anti-twisting function while maintaining its planarization advantages.
Solution Approach 2:
The patent modifies the chemical composition parameters of the organic underlayer film by controlling the ratio of naphthol novolak resin to phenolic resin/resinoid, and by controlling molecular weight and sulfur content. These parameter changes enable the film to simultaneously achieve filling, planarization, and anti-twisting properties.
3Reliability
If the sulfur content in the condensate is reduced to 100 ppm or less, then the filterability and pattern-curving resistance improve, but the manufacturing process becomes more complex requiring precise filtration
Solution Approach 1:
The patent performs preliminary filtration of the condensate to remove particles and impurities before the condensation reaction. This preliminary action ensures that the sulfur content is reduced to 100 ppm or less and prevents particle contamination that would cause pattern defects, thereby achieving high pattern-curving resistance while managing filtration complexity through advance preparation.
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 organic film effectively prevents line collapse and twisting in high-aspect line patterns finer than 40 nm, enhancing manufacturing yield and pattern transfer precision in semiconductor devices.
Implementation Method 1
a composition for forming an organic film, comprising a condensate (A), which is a condensation product of dihydroxynaphthalene shown by the following formula (1) and a condensation agent, or a derivative of the condensate (A)
Data Source
AI summary
The invention provides: a composition for forming an organic film, the composition having high filterability and enabling formation of an organic film which has high pattern-curving resistance, and which prevents a high-aspect line pattern particularly finer than 40 nm from line collapse and twisting after dry etching; a method for forming an organic film and a patterning process which use the composition; and a substrate for manufacturing a semiconductor device, including the organic film formed on the substrate. The composition for forming an organic film includes a condensate (A), which is a condensation product of dihydroxynaphthalene shown by the following formula (1) and a condensation agent, or a derivative of the condensate (A). A sulfur content among constituent elements contained in the condensate (A) or the derivative of the condensate (A) is 100 ppm or less in terms of mass.