Research Information System
10th International Conference on Materials Science and Nanotechnology for Next Generation, MSNG2023, Kayseri, Turkey, 27 - 29 September 2023, pp.35-36, (Summary Text)
Counterfeit
products and identity violations pose an increasing threat to the world
economy, national security, and human health. The importance of ensuring the
security of critical documents, information, and objects is increasing.
Therefore, a new generation of encoding approaches is needed. An approach that
has attracted increasing interest in recent years is the use of physical
systems instead of mathematical functions. The basis of this approach, known as
"Physically Unclonable Functions (PUFs)," is the use of a physical
system based on stochastic processes to obtain random features that are
inherently resistant to imitation. In this study, we propose a new approach to
fabricating hidden codes with high thermal and mechanical stability. To achieve
this, we fabricated surface-embedded PUF systems by generating nanometer-deep
cavities directly on a substrate surface. This is achieved by fabricating
polymeric structures by electrospraying on a negative tone photoresist.
Electrohydrodynamic instability processes ensure randomness, while polymeric
structures act as masks in the subsequent light exposure step. During exposure
to UV light, the photoresist film has been cross-linked, except for the area
under the polymer structures produced by electrospraying. By removing the
electrosprayed polymer structures and the underlying uncrosslinked photoresist
with a solvent, cavities have been formed at random locations. With the
reactive ion etching process, random patterns embedded in the surface have been
obtained by transferring the cavities opened in the negative tone photoresist
to the substrate below. The integration of the cavities into the substrate has
enabled the PUFs to have mechanical and thermal stability similar to the
substrate. The embedded PUF system showed excellent uniformity and uniqueness.