Acid Amplifiers for EUV Photoresists

An acid amplifier system that improves the capabilities of extreme ultraviolet imaging (13.5 nm) and electron-beam lithography. 

Background:
Extreme ultraviolet (EUV) imaging is an optical technology that enables smaller feature sizes in semiconductor chips, which pushes device performance forward. It works by first producing a pattern by exposing a reflective photomask to UV light. The UV light is then reflected onto a substrate covered by a photoresist. Applications for this process include semiconductor device fabrication. However, EUV photoresist performance remains one of the largest barriers to EUV technology implementation, because it is difficult to simultaneously meet performance targets for resolution, line width roughness (LWR) and sensitivity. For example, low concentrations of acid during imaging will yield rough lines (high LWR), but good sensitivity; while high concentrations of acid will give smoother lines, but poor sensitivity.

Technology Overview: 
This technology is a new design for acid amplifiers for use in photoresists at many different wavelengths, especially EUV. These acid amplifiers can also be used for 193 nm shrink technology. These new compounds enable the formulation of photoresists that are capable of generating large concentrations of acid per photon, essentially increasing the quantum yield of the resist system. The acid amplifiers (a) decompose rapidly in the presence of catalytic acid, (b) generate strong acid capable of transforming EUV resist polymers, and (c) are thermally stable in the absence of catalytic acid. These new compounds enable the development of EUV photoresists capable of providing the resolution, line width roughness, and sensitivity required for the 32 and 22 nm nodes.  

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Advantages: 

• Better optimization among resolution, line width roughness, and sensitivity
• Fulfills performance requirements for 32 and 22 nm nodes
• Enables the use of shorter EUV wavelengths, allowing the lithographic fabrication of smaller circuits.
• Can also be used for electron beam lithography and 193 nm shrink technology.

Applications: 

• Extreme Ultraviolet (EUV) lithography.
• Electron Beam lithography.
• Semiconductor device fabrication.

Intellectual Property Summary:
Issued patent: US8501382B1, “Acid Amplifiers.”

Stage of Development:
TRL 3 - Experimental proof of concept

Licensing Status:
This technology is available for licensing.

Licensing Potential:
This technology would be of interest to manufacturers of electronic components that use EUV fabrication, including:

• Photoresist manufacturers
• Semiconductor manufacturers
• Electronic components and instruments manufacturers.
• Research institutions