Radiation-Sensitive Resin Composition for Lithography
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Solution Overview
Problem
Current radiation-sensitive resin compositions for microfabrication face challenges in achieving favorable sensitivity to exposure light and superior Critical Dimension Uniformity (CDU) and Line Width Roughness (LWR) performance, particularly at line widths of 40 nm or less.
Innovation Solution
A radiation-sensitive resin composition incorporating a polymer with an acid-labile group and a specific compound represented by formula (1), which includes a sulfonic acid anion and a group capable of generating acid upon irradiation, enhancing the sensitivity and performance of resist patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional radiation-sensitive resin compositions are used, then basic resist pattern formation is achieved, but sensitivity to exposure light and CDU/LWR performance are insufficient at line widths of 40 nm or less
Solution Approach 1:
The patent employs a composite resin composition comprising multiple polymer components (polymer A with acid-labile group, polymer B without acid-labile group) and a specific onium salt compound. This composite approach allows optimization of both sensitivity and CDU/LWR performance by combining materials with complementary properties, where polymer A provides acid generation and polymer B provides structural stability for improved line width control.
Solution Approach 2:
The patent systematically optimizes compositional parameters including the ratio of polymer A to polymer B (0.1-10 mass ratio), concentration of onium salt (1-50 mass%), and molecular weight characteristics (polystyrene-equivalent weight average molecular weight). These parameter adjustments enable fine-tuning of resist performance to achieve both high sensitivity and superior CDU/LWR at 40 nm line widths.
2Productivity
If sensitivity to exposure light is increased, then resist pattern formation becomes more efficient, but CDU and LWR performance deteriorates
Solution Approach 1:
The patent introduces spatial differentiation in material properties through the use of acid-labile groups that selectively react in exposed regions. Polymer A contains these acid-labile groups that undergo chemical change only in irradiated areas, creating local property variations that enable high sensitivity while maintaining overall pattern uniformity and controlling line width roughness through differential solubility changes.
Solution Approach 2:
The onium salt compound acts as an intermediary that mediates between the exposure light and the polymer matrix. It serves as an acid generating agent that converts optical energy into chemical energy (acid), which then triggers the solubility change in polymer A. This intermediary mechanism enables efficient energy transfer while maintaining precise control over the chemical reaction, thereby achieving both high sensitivity and good CDU/LWR 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
The composition enables the formation of resist patterns with improved sensitivity to exposure light and superior CDU and LWR performance, suitable for advanced microfabrication processes such as semiconductor device manufacturing.
Implementation Method 1
a radiation-sensitive resin composition for use in microfabrication by lithography generates an acid at light-exposed regions upon an irradiation with a radioactive ray
Implementation Method 2
A chemical reaction in which the acid serves as a catalyst causes a difference between the light-exposed regions and light-unexposed regions in rates of dissolution in a developer solution
Data Source
AI summary
A radiation-sensitive resin composition includes: a polymer including a structural unit including an acid-labile group; and a compound represented by formula (1). R1, R2, and R3 each independently represent a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms; X1, X2, and X3 each independently represent a group represented by formula (2); a sum of d, e, and f is no less than 1; R4 represents a hydrocarbon group having 1 to 20 carbon atoms and R5 represents a hydrocarbon group having 1 to 20 carbon atoms, or R4 and R5 taken together represent a heterocyclic structure having 4 to 20 ring atoms, together with the sulfur atom to which R4 and R5 bond; n is 0 or 1; A− represents a monovalent sulfonic acid anion; and Y represents —COO—, —OCO—, or —N(R7)CO—.