Silicon Antireflective Film Stack for Fine Pattern Edge Control
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Solution Overview
Problem
The challenge is to develop a patterning process that can form fine patterns without edge roughness while maintaining high precision and dry etching resistance, especially under advanced ArF immersion and high-NA exposure conditions.
Innovation Solution
The process involves a multilayer resist method with a specific layering of an organic underlayer film, a silicon-containing hard mask, a silicon-containing antireflective film, and a photoresist film. The silicon-containing antireflective film is formed using a composition containing a crosslinking agent and a polysiloxane with specific repeating units, which enhances both antireflective and dry etching resistance properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the photoresist film thickness is reduced to maintain resolution at finer pattern sizes, then the resolution performance is improved, but the dry etching resistance is reduced
Solution Approach 1:
The patent divides the single photoresist film into multiple functional layers: a thin photoresist film for high-resolution patterning and a separate organic underlayer film for dry etching resistance. This segmentation allows each layer to be optimized independently - the photoresist film can be made very thin for fine pattern resolution while the underlayer provides the necessary etching protection during substrate processing.
2Measurement precision
If a resin with low light absorption is used to improve resolution at shorter exposure wavelengths, then the resolution is improved, but the etching rate under dry etching conditions increases
Solution Approach 1:
The patent separates the optical function (low light absorption for resolution) from the etching function (resistance to dry etching). The photoresist film uses resins optimized for light transmission at exposure wavelengths, while the organic underlayer film provides the etching resistance that would be compromised if the same material were used for the photoresist.
Solution Approach 2:
The organic underlayer film acts as an intermediary between the photoresist film and the substrate. It receives the transferred pattern from the photoresist and protects the substrate during dry etching, while also providing poisoning suppression to prevent damage to the photoresist film during underlayer processing.
3Manufacturing precision
If a silicon-containing antireflective film with high refraction is used to suppress edge roughness, then the antireflective performance is improved, but the dry etching resistance may be compromised
Solution Approach 1:
The organic underlayer film serves as a mediator between the silicon-containing antireflective film and the substrate. It receives the pattern transfer from the resist and provides the necessary dry etching resistance and poisoning suppression, allowing the antireflective film to focus on its primary function of reducing edge roughness without compromising etching performance.
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
This approach allows for the precise transfer of resist patterns to the substrate with reduced edge roughness and improved antireflective performance, even at the 15 nm or less pattern rule, thereby addressing the limitations of existing technologies.
Implementation Method 1
a silicon-containing antireflective film which is formed using a composition containing a crosslinking agent and a polysiloxane
Implementation Method 2
the silane-modified polyhydroxystyrene and a crosslinking agent, and the silane crosslinked structure formed by these
Data Source
AI summary
The present invention is a patterning process including the steps of: providing an organic underlayer film, a silicon-containing hard mask, a silicon-containing antireflective film, and a photoresist film in this order on a substrate to be processed; forming a resist pattern in the photoresist film; forming a hard mask middle layer film pattern; forming an organic underlayer film pattern; and forming a pattern in the substrate to be processed, where the silicon-containing antireflective film is formed using a composition for forming a silicon-containing antireflective film containing a crosslinking agent and a polysiloxane containing any one or more of a repeating unit represented by the following general formula (Sx-1), a repeating unit represented by the following general formula (Sx-2), and a partial structure represented by the following general formula (Sx-3). This provides a patterning process according to which it is possible to form a fine pattern without edge roughness.