Stacked transistor physically unclonable function

Abstract

An IC device includes a first and second stacked transistor structures including respective first and second and third and fourth transistors in a semiconductor substrate, first and second bit lines and a word line on one of a front or back side of the semiconductor substrate, and a power supply line on the other of the front or back side. The first transistor includes a source/drain (S/D) terminal electrically connected to the first bit line, a S/D terminal electrically connected to a S/D terminal of the second transistor, and a gate electrically connected to the word line, the third transistor includes a S/D terminal electrically connected to the second bit line, a S/D terminal electrically connected to a S/D terminal of the fourth transistor, and a gate electrically connected to the word line, and the second and fourth transistors include S/D terminals electrically connected to the power supply line.