Negative Development Resist Film for Immersion Lithography
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Solution Overview
Problem
In semiconductor manufacturing, existing methods face challenges in forming high-quality patterns with reduced scum, improved line edge roughness, and enhanced in-plane uniformity during immersion lithography, particularly due to issues with resist degradation and immersion liquid compatibility.
Innovation Solution
A pattern formation method involving a resist composition with a resin that increases polarity upon acid action, combined with a negative developer and organic solvent, forming a resist film with a receding contact angle of 70 degrees or more, and using a negative developer comprising organic solvents like ketones, esters, or ethers, to achieve selective dissolution and improved liquid mobility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If immersion lithography is used to improve resolution, then manufacturing precision is improved, but resist degradation occurs and scum formation increases
Solution Approach 1:
The patent changes the chemical parameters of the resist composition by incorporating specific resins with carboxyl groups and controlling the ratio of polar to non-polar groups. This modifies the resist's interaction with the immersion liquid, reducing scum formation while maintaining the resolution benefits of immersion lithography.
Solution Approach 2:
The patent uses a composite resist composition containing multiple resin types (aromatic ring-containing resin, alicyclic hydrocarbon resin, and resin with carboxyl groups) in specific ratios. This composite structure balances hydrophobicity for following capability and hydrophilicity for reduced scum, resolving the contradiction between resolution and scum formation.
2Manufacturing precision
If immersion lithography is used to improve resolution, then manufacturing precision is improved, but line edge roughness increases
Solution Approach 1:
The patent optimizes the chemical composition parameters of the resist, specifically controlling the content of resins with carboxyl groups (0.1-10 mass%) and the overall polarity ratio. These parameter changes improve the uniformity of resist dissolution, resulting in smoother line edges while preserving the high resolution achieved through immersion lithography.
3Speed
If resist film is made hydrophobic to improve following capability of immersion liquid, then speed is improved, but scum formation increases
Solution Approach 1:
The patent applies local quality by creating different hydrophobic/hydrophilic characteristics in different parts of the resist molecular structure. The resist contains both hydrophobic components (for following capability) and hydrophilic components (carboxyl groups, for reduced scum), with each serving its function in the appropriate local context of the resist film.
Solution Approach 2:
The resist composition is designed as a composite material combining hydrophobic resins (aromatic ring-containing and alicyclic hydrocarbon resins) with hydrophilic resins (containing carboxyl groups). This composite structure enables the resist to simultaneously achieve good following capability and reduced scum formation by balancing opposing properties within the same material system.
Data Source
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Figure 3(a)~3(b)
AI summary
A method of forming patterns includes (a) coating a substrate with a resist composition for negative development to form a resist film having a receding contact angle of 70 degrees or above with respect to water, wherein the resist composition for negative development contains a resin capable of increasing the polarity by the action of an acid and becomes more soluble in a positive developer which is an alkaline developer and less soluble in a negative developer comprising an organic solvent upon irradiation with an actinic ray or radiation, (b) exposing the resist film via an immersion medium, and (c) performing development with a negative developer comprising an organic solvent.