Metal-Containing Top Coat for EUV Lithography Sensitivity
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Solution Overview
Problem
Current EUV lithography processes face challenges in patterning features at sub-10 nm production nodes due to limited EUV radiation source output power, resulting in lengthy wafer exposure times and high power requirements.
Innovation Solution
A metal-containing top coat is applied over a resist layer in a multi-layer patterning material film stack to increase EUV sensitivity, reducing exposure times and power requirements by enhancing the absorption of EUV radiation, which can be formed through deposition or self-segregation techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If EUV lithography is used for sub-10 nm patterning, then patterning precision is improved, but exposure time increases due to limited source output power
Solution Approach 1:
A metal-containing top coat layer is introduced as an intermediary between the EUV radiation source and the resist layer. This top coat has high absorption coefficient for EUV radiation, acting as a mediator that converts EUV photons into secondary electrons that then expose the resist, thereby reducing the required exposure time while maintaining patterning precision
Solution Approach 2:
The invention changes the physical and chemical parameters of the patterning material film stack by incorporating a metal-containing top coat with specific properties (high atomic number, high EUV absorption coefficient). This parameter change enhances the overall sensitivity of the resist system to EUV radiation, allowing faster exposure times without sacrificing patterning quality
2Productivity
If EUV source output power is increased to reduce exposure time, then wafer throughput is improved, but power requirements and manufacturing costs increase
Solution Approach 1:
The metal-containing top coat serves as an efficient intermediary that enhances the coupling between EUV radiation and the resist material. By using a top coat with high absorption coefficient, the system achieves better utilization of the available EUV source power, reducing the need to increase source output power to improve wafer throughput
Solution Approach 2:
The invention uses a composite patterning material film stack consisting of the metal-containing top coat combined with the resist layer. This composite structure leverages the high absorption properties of the metal top coat and the pattern-forming capabilities of the resist, achieving high productivity without requiring excessive source power
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
This approach significantly increases wafer throughput rates and reduces manufacturing costs by improving EUV sensitivity without compromising pattern resolution or quality metrics like line edge roughness and line width roughness.
Implementation Method 1
increasing the EUV sensitivity of a patterning material film stack so as to reduce required wafer exposure times and/or power requirements of EUV radiation sources
Implementation Method 2
The metal-containing top coat can be formed, for example, by atomic layer deposition or spin-on deposition over the resist layer, or by self-segregation from the resist layer
Data Source
AI summary
A lithographic patterning method includes forming a multi-layer patterning material film stack on a semiconductor substrate, the patterning material film stack including a resist layer formed over one or more additional layers, and forming a metal-containing top coat over the resist layer. The method further includes exposing the multi-layer patterning material film stack to patterning radiation through the metal-containing top coat to form a desired pattern in the resist layer, removing the metal-containing top coat, developing the pattern formed in the resist layer, etching at least one underlying layer in accordance with the developed pattern, and removing remaining portions of the resist layer. The metal-containing top coat can be formed, for example, by atomic layer deposition or spin-on deposition over the resist layer, or by self-segregation from the resist layer.