Nonvolatile phase change memory nanocell fabrication by femtosecond laser writing assisted with near-field optical microscopy
The phase change memory cells were developed by using a combination system of a femtosecond laser with near-field scanning optical microscopy. The memory cells with feature size varying from 800nm down to 90nm were achieved. The cell functional performances were tested, and the scalability of the programming current as a function of the memory cell features was investigated. The optical near-field distance which is one of the critical factors to achieve high resolution nanostructures was studied experimentally with the consideration of the whole fabrication process for functional devices. The Bethe-Bouwkamp model was employed to study the effects of the optical near-field distance to the nanostructure geometry. The programming current of 0.8mA was observed for the memory nanocell at a feature size of 90nm.
Adopting a nonlinear dynamical system analysis point of view, we discuss the design of a low-complexity CMOS electronic circuit implementing a Physically Unclonable Function core module based on a two-neurons Cellular Neural Network. The study follows a theoretical approach investigating the circuit topology, aiming at proposing a methodological engineering approach for the design of this class of systems.