Physical Random-Number Generator Using Schottky MOSFET

A new physical random-number generator using a metal oxide semiconductor field-effect transistor (MOSFET) whose source and drain are made of Schottky contacts is proposed. MOSFETs, which have PtSi source and drain contacts, are fabricated on a silicon-on-insulator. It was found that large noise appears in the drain current of the PtSi Schottky-source/drain MOSFET when it is operated as an n-channel transistor. The noise spectrum in the frequency range up to 400 kHz shows that the noise is frequency-dependent, which is similar to the noise of a conventional pn-junction MOSFET. A circuit in which an inverter consisting of two Schottky MOSFETs is used as the noise source is proposed to create a random binary signal. The circuit is demonstrated to be able to create a binary signal array whose characteristic is close to a quasi-random number generated by a computer.