Radiation-Sensitive Resist Composition for Fin-FET Lithography Scum Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithography methods face challenges in forming fine patterns of less than 0.3 μm with high accuracy, especially in three-dimensional structures like Fin-FETs, due to insufficient light exposure leading to resist scum and difficulties with antireflection films, which affects the solubility and patterning of resist materials.
Innovation Solution
A radiation-sensitive composition comprising a polymer blend of partially protected polyhydroxystyrene and partially protected (meth)acrylic resins, combined with a non-ionic radiation-sensitive acid generator, which enhances development dissolution rates and reduces scum formation even in areas with low exposure, such as the foot of steps and intersections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional resist materials are used in lithography processes for three-dimensional structures, then the lithography process can be performed, but insufficient light reaches the foot of steps causing low solubility and scum formation
Solution Approach 1:
The patent changes the chemical composition parameters of the resist material by using a polymer with specific repeating units containing acid-labile groups (formula 1) combined with a radiation-sensitive acid generator. This parameter change enables the resist to achieve both high-resolution patterning and reliable solubility even in low-light exposure areas like step feet, eliminating scum formation while maintaining manufacturing precision.
Solution Approach 2:
The patent creates a composite resist system combining a specific polymer (formula 1) with a radiation-sensitive acid generator. This composite material approach allows the resist to simultaneously achieve high pattern formation accuracy and reliable solubility by leveraging the complementary properties of both components, solving the contradiction between precision and reliability.
2Manufacturing precision
If deep ultraviolet rays are used for lithography to achieve higher integration, then manufacturing precision improves, but the complexity of the lithography process increases
Solution Approach 1:
The patent adapts the resist material parameters to work effectively with deep ultraviolet lithography by incorporating radiation-sensitive acid generators and acid-labile groups that are specifically responsive to deep UV radiation. This parameter optimization enables high manufacturing precision with deep UV while managing process complexity through targeted material chemistry rather than requiring complex process adjustments.
3Manufacturing precision
If standing wave effects and reflection from substrate are considered, then accurate patterning becomes difficult, but using conventional resist materials fails to prevent scum
Solution Approach 1:
The patent converts the harmful effect of standing waves and reflection into a beneficial outcome by using a resist material (polymer formula 1 with acid generator) that is specifically designed to respond to these optical effects. The acid-labile groups and radiation-sensitive acid generator work together to ensure complete dissolution even in areas affected by standing waves, transforming what would normally cause scum into a controlled chemical reaction that eliminates scum formation while maintaining pattern accuracy.
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 composition achieves high scum margin and favorable resist pattern shapes, improving the lithography process for complex integrated circuit structures by ensuring effective development and reducing residue issues.
Implementation Method 1
a radiation-sensitive acid generator which generates an acid by irradiation of radiation
Data Source
AI summary
A radiation-sensitive composition includes a polymer composition and a radiation-sensitive acid generator. The polymer composition includes a first polymer and a second polymer. The first polymer includes a repeating unit shown by a following formula (1). The second polymer includes a repeating unit shown by a following formula (2) and does not include a repeating unit shown by the formula (1).