Novolak Resin with Hexafluoroisopropanol Group for Heat Resistance and Alkali Dissolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Novolak resins used in photolithography and semiconductor sealing materials face challenges in achieving a balance between heat resistance, moisture resistance, transparency, and alkali dissolution rate, with existing solutions either compromising on sensitivity or suffering from yellowing and poor storage stability.
Innovation Solution
A novolak resin containing a hexafluoroisopropanol group is developed, which enhances alkali dissolution rate and maintains heat resistance and transparency by introducing the HFIP group into the polymer structure, allowing it to function as an effective hardening agent for epoxy resins while preventing yellowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the molecular weight of novolak resin is raised to improve heat resisting property, then heat resistance is improved, but sensitivity of resist decreases
Solution Approach 1:
The patent introduces a fluorinated isopropanol group (HFIP group) containing fluorine atoms into the novolak resin structure. This chemical modification changes the physical and chemical parameters of the resin, enabling it to achieve both high heat resistance and high sensitivity without the trade-off that occurs with simple molecular weight increase. The fluorine atoms provide thermal stability while maintaining the resin's solubility and reactive properties needed for sensitivity.
Solution Approach 2:
The patent creates a composite structure by combining novolak resin with fluorinated isopropanol groups. This composite approach integrates the heat-resistant characteristics of fluorinated compounds with the photolithographic properties of novolak resin, achieving a material that simultaneously possesses high heat resistance and high sensitivity for photolithography applications.
2Temperature
If alkylphenol such as xyleneol and trimethylphenol is used to improve heat resisting property, then heat resistance is improved, but the improvement of heat resisting property was small
Solution Approach 1:
The patent employs fluorinated isopropanol groups containing multiple fluorine atoms, which fundamentally changes the thermal stability parameters compared to conventional alkylphenols. The C-F bonds provide superior thermal stability, resulting in significantly higher heat resistance improvement rather than the marginal improvements seen with alkylphenols like xyleneol and trimethylphenol.
3Temperature
If epoxy resin using phenolic resin as hardening agent is used to achieve heat resisting property and moisture resistant property, then heat resistance and moisture resistance are improved, but coloring by oxidation occurs deteriorating transparency
Solution Approach 1:
The patent uses the fluorinated isopropanol group to convert the harmful oxidation process into a beneficial outcome. The HFIP group contains fluorine atoms that resist oxidation, preventing the coloring that would normally occur in epoxy-phenolic resin systems. This transforms the potential harm of oxidation into a benefit by providing oxidation resistance and maintaining transparency while still achieving heat and moisture resistance.
4Reliability
If conventional novolak resin is used to achieve high resolving power and good sensitivity, then photolithography performance is improved, but alkali dissolution rate is insufficient
Solution Approach 1:
The patent modifies the novolak resin by introducing fluorinated isopropanol groups, which changes the chemical parameters to enhance alkali dissolution rate while preserving the resolving power and sensitivity. The fluorine atoms alter the resin's interaction with alkaline development solutions, accelerating dissolution without compromising the pattern definition capabilities.
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 HFIP group-containing novolak resin exhibits a high alkali dissolution rate, maintaining heat resistance and transparency even at high temperatures, and prevents yellowing when used as a hardening agent for epoxy resins, improving the performance in photolithography and semiconductor applications.
Implementation Method 1
the rate of dissolution in the alkaline development solution (hereinafter it may be referred to as 'Alkali Dissolution Rate') is large
Implementation Method 2
it is also an important property that dissolution in the alkaline development solution is fast... having heat resisting property
Implementation Method 3
this epoxy resin has problems like coloring by oxidation in preservation of transparency
Data Source
AI summary
Disclosed is a novolak resin containing a repeating unit represented by the general formula (1). R1is a hydrogen atom or an alkyl group which is C1-4 straight-chain or C3-4 branched-chain, and some or all hydrogen atoms in the alkyl group may be replaced with a fluorine atom; R2 is a hydrogen atom, a phenyl group, an alkyl group which is C1-10 straight-chain or C3-10 branched-chain, or an alkyl group having a C3-10 cyclic structure, and some or all hydrogen atoms in the phenyl group and the alkyl group may be replaced with fluorine atoms; each of a and b is independently an integer of 1-3, and these are defined as 2≦a+b≦4; and d is an integer of 0-2. This novolak resin has high dissolution rate in the alkaline development solution in addition to the heat resisting property which is a property of phenolic resin.