Biphenyl Derivative Resist Bottom Layer for Lithography
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Solution Overview
Problem
Current resist bottom layer materials for lithography face challenges in achieving optimal refractive indices, etch resistance, heat resistance, and solvent resistance while maintaining pattern integrity and preventing twist during substrate etching, especially when exposed to high temperatures and etching processes.
Innovation Solution
A biphenyl derivative-based resist bottom layer material is developed, comprising specific chemical structures that can be used to form a multilayer resist film, which includes a biphenyl derivative with benzene or naphthalene rings, capable of reducing reflectance, providing etch resistance, heat resistance, and solvent resistance, and is suitable for use in lithography processes involving high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resist bottom layer materials are used, then the lithography process can proceed, but the materials cannot achieve optimal refractive indices, etch resistance, heat resistance, and solvent resistance simultaneously, leading to pattern twist during substrate etching
Solution Approach 1:
The patent employs a composite material system consisting of a biphenyl derivative polymer matrix combined with specific additives and modifiers. The biphenyl derivative provides the base structure with inherent thermal stability, while the composite formulation achieves optimal refractive index, etch resistance, heat resistance, and solvent resistance properties that cannot be obtained with conventional single materials.
2Productivity
If high temperatures are applied during substrate etching, then the etching process can be effective, but conventional resist bottom layer materials undergo degradation and twist, compromising pattern precision
Solution Approach 1:
The patent modifies the chemical structure parameters of the resist bottom layer material by using a biphenyl derivative with specific molecular weight, functional groups, and structural characteristics. These parameter changes enable the material to maintain compositional stability at high etching temperatures while conventional materials degrade and twist.
3Loss of energy
If the refractive index of the resist bottom layer is adjusted to reduce reflectance, then antireflective coating function is improved, but etch resistance and heat resistance are compromised
Solution Approach 1:
The patent applies local quality by creating a resist bottom layer material with spatially differentiated functional properties. The biphenyl derivative structure provides localized regions with optimized refractive index for antireflective function, while other regions maintain etch resistance and heat resistance, allowing all properties to coexist without mutual compromise.
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 biphenyl derivative-based resist bottom layer material achieves optimal refractive indices, improved etch resistance, and solvent resistance, preventing pattern twist during substrate etching and withstanding high temperatures, thus enhancing the reliability and precision of lithography processes.
Implementation Method 1
the reflectance from the resist bottom layer back into the resist top layer must be reduced to or below 1%
Implementation Method 2
withstanding high temperatures, thus enhancing the reliability and precision of lithography processes
Implementation Method 3
must have high etch resistance since it serves as a mask when the underlying substrate is subsequently etched
Implementation Method 4
preventing pattern twist during substrate etching
Data Source
AI summary
A biphenyl derivative having formula (1) is provided wherein Ar1 and Ar2 denote a benzene or naphthalene ring, and x and z each are 0 or 1. A material comprising the biphenyl derivative or a polymer comprising recurring units of the biphenyl derivative is spin coated and heat treated to form a resist bottom layer having improved properties, optimum values of n and k, step coverage, etch resistance, heat resistance, solvent resistance, and minimized outgassing.