A Poly‐Crystalline Silicon Nanowire Transistor with Independently Controlled Double‐Gate for Physically Unclonable Function by Multi‐States and Self‐Destruction

Abstract

AbstractWith the advance of internet of things, numerous electronic devices are being connected to each other through the internet. As the number of connections has increased, security has become increasingly important. Physically unclonable function (PUF) is one of the essential approaches that can be used to secure data in device. In this work, an independently controlled double‐gate (ICDG) transistor composed of a poly‐crystalline silicon (poly‐Si) nanowire channel for PUF is first demonstrated. Simply fabricated using CMOS processes, the so‐called PUF transistor harnesses multi‐states and self‐destruction for advanced security. The randomness in the poly‐Si nanowire channel is established by the randomly distributed poly‐Si grains. This random distribution means each transistor has a different threshold voltage (Vth). Moreover, multi‐states composed of a primary bit and a secondary bit, can be distinguished by gate‐biasing. The primary bit is identified by applying the same gate voltage to an electrically tied double‐gate. The secondary bit is discerned by applying a different gate voltage to the ICDG. Security key capacity is doubled using the multi‐states, without increasing footprint. Based on reinforced randomness, the PUF transistor exhibits enhanced uniqueness and unpredictability. In addition, this PUF transistor is untraceable by electrical self‐destructibility when external hacking is attempted.