Synopsys, Inc.
Using threading dislocations in GaN/Si systems to generate physically unclonable functions

Abstract:

The independent claims of this patent signify a concise description of embodiments. Roughly described, a physically unclonable function (PUF) device includes a crystalline substrate and a stack of crystalline layers on top. The stack is grown epitaxially such that lattice mismatch causes threading dislocations from the substrate to the top surface of the stack. Diodes are formed on the top surface by forming anode material on the top surface of the stack, thereby forming a diode junction with a cathode region below. A diode which includes a threading dislocation has a higher leakage current than one that does not. Circuitry connected to the diodes interrogates the array and outputs binary values indicating, for each of the diodes, whether the diode includes a threading dislocation. Such binary values can be used as the PUF of the chip. This Abstract is not intended to limit the scope of the claims.