Atomic Force Microscopy-Based Static Plowing Lithography Using CaCO3 Nanoparticle Resist Layers as a Substrate-Flexible Selective Metal Deposition Resist

• Published in: Journal of physical chemistry. C 2021-10, Vol.125 (42), p.23490-23500
• Main Authors: Ulapane, Sasanka B, Doolin, Jennifer L, Okeowo, Monisola K, Berrie, Cindy L
• Format: Article
• Language: English
• Subjects: C: Physical Properties of Materials and Interfaces
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.1c07239

Atomic force microscopy (AFM) tip-based fabrication has gained attention due to its unparalleled precision and control for designing nano- and microscale features. Such features have utility in applications including miniaturized electronics, biological sensing, and plasmonics. Herein, we discuss an AFM tip-based plowing approach to create patterns on the micron scale in a thin CaCO3 nanoparticle (NP) film, deposited over a wide range of substrates. The CaCO3 NP layer’s high thermal stability allows it to be used as a resist film during high vacuum thermal evaporation of gold. After metal deposition, the NP resist film is selectively removed in aqueous solutions either by complexing with ethylenediaminetetraacetic acid or by dissolution with dilute HCl. The resulting gold metal features on surfaces were characterized by AFM and optical microscopy. The metal features were commensurate with the patterns created in the NP film. This fabrication approach was demonstrated on glass, Si, and mica, and the metal features show reasonable adhesion and stability. This patterning approach is unique in that it allows for the deposition of precisely placed metal microstructures with a defined size, shape, placement, and orientation on various substrates while using simple, easily removable resists. Salt-based resists can be removed in aqueous solutions with minimal contamination or damage to the metal features. This versatile method could be used to deposit fixed metal features on any desired substrate for applications from sensors to electronics. This is particularly useful for applications with conductive structures on optically transparent substrates, which are more challenging to fabricate with other approaches.