Thermal probe maskless lithography for 27.5 nm half-pitch Si technology
Lin Lee Cheong1, Philip Paul, Felix Holzner
1IBM Research-Zurich , Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland.
Nano Letters
|August 23, 2013
Summary
Thermal scanning probe lithography achieves 27.5 nm half-pitch density using a novel resist process. This maskless lithography technique yields high-aspect ratio patterns with excellent line-edge roughness, suitable for advanced applications like extreme ultraviolet mask fabrication.
Area of Science:
- Materials Science
- Nanotechnology
- Lithography
Background:
- Advanced lithography is crucial for microelectronics fabrication.
- Current methods face limitations in feature density and precision.
- Maskless lithography offers a flexible alternative for pattern generation.
Purpose of the Study:
- To demonstrate thermal scanning probe lithography for high-density pattern creation.
- To achieve high-aspect ratio binary patterns with minimal line-edge roughness.
- To evaluate the process for applications such as extreme ultraviolet mask manufacturing.
Main Methods:
- Utilized thermal scanning probe lithography on a high carbon content organic resist.
- Employed a thin silicon dioxide hard mask and reactive ion etching for pattern transfer.
- Transferred patterns into both the resist and the silicon substrate.
Main Results:
- Achieved a 27.5 nm half-pitch line density in the resist.
- Generated high-aspect ratio binary patterns with 8 nm initial depth.
- Obtained a line-edge roughness of 2.7 nm (3σ) after pattern transfer.
- Successfully transferred patterns into 50 nm deep silicon structures with conformal accuracy.
Conclusions:
- Thermal scanning probe lithography is a viable maskless technique for high-resolution patterning.
- The developed process meets critical requirements for feature density and line-edge roughness.
- This method shows promise for fabricating components like extreme ultraviolet masks.
