In-Situ Dry Development for EUV Hard Mask Pattern Transfer
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Solution Overview
Problem
EUV photoresists face challenges with pattern distortion and etch transfer issues due to thin film thickness and low EUV absorption, leading to defects in high aspect ratio areas, especially with critical dimensions less than 30 nm, and conventional development processes suffer from capillary forces.
Innovation Solution
Implementing etching tools and methods for in-situ dry development and etching of EUV photoresist patterns into hard mask material, using integrated or sequential dry develop and hard mask etching chambers, and hybrid wet/dry development processes to mitigate pattern distortion and residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet development process is used, then photoresist development is achieved, but pattern distortion and defects occur due to capillary forces
Solution Approach 1:
The patent changes the physical state of the development process from liquid (wet) to gaseous (dry), eliminating capillary forces that cause pattern distortion. The dry development process uses vapor-phase chemicals to develop the photoresist pattern without liquid contact, thereby preventing the harmful capillary effects during development.
Solution Approach 2:
The patent replaces the mechanical/chemical wet development process with a plasma-based dry development process. Instead of using liquid developers that create capillary forces, the invention uses controlled plasma chemistry to achieve pattern development, substituting a physical-chemical mechanism that avoids mechanical distortion forces.
2Reliability
If conventional wet development is used, then photoresist is developed, but etch resistance is insufficient for high aspect ratio patterns
Solution Approach 1:
The patent merges the development and etching processes into a single integrated dry development/etch chamber. The dry development process is performed in-situ within the same chamber that subsequently performs the etch process, allowing the developed photoresist pattern to immediately receive etch protection without transfer to another chamber, thereby enhancing etch resistance for high aspect ratio patterns.
Solution Approach 2:
The patent implements continuous processing where the photoresist pattern development and subsequent etching occur in continuous sequence within the same chamber environment. The dry developed pattern remains in the chamber and is immediately subjected to the etch process, maintaining continuous protective action without interruption or transfer that would compromise pattern integrity.
3Ease of manufacture
If separate development and etching chambers are used, then process modularity is achieved, but in-situ dry development and etching cannot be performed
Solution Approach 1:
The patent designs the processing chamber to serve multiple functions: it can perform dry development, etching, and potentially other semiconductor processing operations. The chamber is equipped with gas delivery systems and plasma generation capabilities that enable it to switch between different process modes, making it a universal processing platform rather than a single-function chamber.
Solution Approach 2:
The patent implements a dynamic chamber configuration where the chamber can transition between different process modes (development, etching, cleaning) through programmable gas flow control and plasma parameter adjustment. The system dynamically adapts its chemistry and physical conditions based on the required process step, enabling flexible in-situ processing sequences.
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
Reduces cycle time and manufacturing costs while improving pattern integrity and reducing defects in EUV photoresist patterns, especially for critical dimensions below 30 nm, by avoiding capillary forces and enhancing etch resistance.
Implementation Method 1
an etch chamber for plasma etching a first wafer to be processed
Implementation Method 2
a dry develop chamber to dry develop a photo resist layer on the first wafer
Data Source
AI summary
An embodiment etching tool includes an etch chamber for plasma etching a first wafer to be processed; a transfer chamber coupled to the etch chamber; a first run path between the transfer chamber and the etch chamber, the first run path including a path for moving the first wafer to be processed from the transfer chamber to the etch chamber, where the etching tool is configured to dry develop the first wafer to be processed before etching a hard mask on the first wafer in the etch chamber.