Positive Resist Composition for Line Width Roughness Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional chemically amplified positive resist compositions are unable to satisfactorily reduce line width roughness (LWR) in semiconductor and liquid crystal display element production, which is critical for achieving higher resolution and pattern miniaturization.
Innovation Solution
A positive resist composition incorporating a polymer compound with specific structural units that exhibit increased alkali solubility upon acid exposure, including structural units derived from (α-lower alkyl) acrylate esters with acid-dissociable, dissolution-inhibiting groups, and an acid generator, which enhances alkali solubility and reduces LWR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional chemically amplified positive resist compositions are used, then the resist can be applied for pattern formation, but the line width roughness (LWR) cannot be satisfactorily reduced
Solution Approach 1:
The patent modifies the chemical structure of the base resin by incorporating specific structural units (a0 and a1) with defined molecular characteristics. The structural unit (a0) contains an alkoxyalkyl group that dissociates upon acid exposure, while structural unit (a1) provides dissolution inhibition. By changing the molecular parameters of the resin and controlling the ratio of these structural units, the patent achieves reduced LWR and improved pattern uniformity while maintaining the chemically amplified positive resist functionality.
Solution Approach 2:
The patent creates a composite resin structure by combining polymer compounds with different functional structural units ((a0) and (a1)) within the same base resin. This composite approach allows the resin to simultaneously exhibit acid-dissociable properties for solubility change and dissolution-inhibiting properties for pattern definition, resolving the contradiction between achieving low LWR and maintaining pattern uniformity in chemically amplified positive resists.
2Measurement precision
If the wavelength of exposure light source is shortened for miniaturization, then higher resolution is achieved, but the control of LWR becomes more difficult
Solution Approach 1:
The patent addresses the LWR control difficulty at shorter wavelengths by changing the chemical parameters of the base resin. The specific structural units (a0) and (a1) are designed to provide controlled solubility changes and dissolution inhibition that are less sensitive to wavelength variations, enabling consistent LWR reduction across different exposure wavelengths including ArF excimer laser (193 nm) and shorter wavelengths.
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 proposed resist composition effectively reduces LWR, improves the rectangular formability of resist patterns, and maintains favorable resolution and dry etching resistance.
Implementation Method 1
an acid generator component (B), wherein the component (A) includes a polymer compound (A1) having a structural unit (a0) represented by a general formula (a0)
Implementation Method 2
a structural unit (a1), which is derived from an (α-lower alkyl) acrylate ester containing an acid-dissociable, dissolution-inhibiting group
Data Source
AI summary
A positive resist composition that includes a resin component (A) and an acid generator component (B), wherein the component (A) includes a polymer compound (A1) having a structural unit (a0) represented by a general formula (a0) shown below, and a structural unit (a1), which is derived from an (α-lower alkyl) acrylate ester containing an acid-dissociable, dissolution-inhibiting group and is not classified as the structural unit (a0):(wherein, R represents a hydrogen atom or a lower alkyl group; Y1 represents an aliphatic cyclic group; Z represents an alkoxyalkyl group; a represents an integer from 1 to 3, and b represents either 0 or an integer from 1 to 2, provided that a+b=1 to 3).