In situ SU-8 silver nanocomposites

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Nanocomposite materials with metal nanoparticles are crucial for photonics and optoelectronics.
• Incorporating preformed nanoparticles into photoresists presents fabrication challenges.

Purpose of the Study:

• To develop an easy, in situ method for fabricating silver nanocomposites within an epoxy-based photoresist (SU-8).
• To enable the creation of structured thin films for optoelectronic applications.

Main Methods:

• In situ reduction of silver nitrate (AgNO3) within SU-8 photoresist.
• Utilizing pre- and post-exposure soft bake steps at 95 °C and a high-temperature treatment at 300 °C.
• Spin coating for thin film formation and UV lithography for structuring.

Main Results:

• Homogeneously distributed silver nanoparticles formed within the SU-8 matrix without agglomeration.
• Successfully fabricated thin films structured using UV lithography with a 5 µm resolution.
• UV exposure time was independent of nanoparticle concentration.
• Achieved high plasmonic responses in the fabricated silver nanocomposites.

Conclusions:

• The developed in situ method simplifies the fabrication of silver-SU-8 nanocomposites.
• These nanocomposites are suitable for creating novel optoelectronic and optical sensing devices.
• The process offers a viable route for integrating plasmonic nanoparticles into micro/nanofabrication workflows.