Using a time invariant statistical process variable of a semiconductor chip as the chip identifier

Abstract

A method for providing an identifier for a semiconductor chip after the manufacture of the semiconductor chip using a fabrication process includes selecting one or more circuit elements formed on the semiconductor chip where each of the circuit elements having an electrical parameter that has a time-invariant statistical process variation, measuring data values of the electrical parameter of the one or more circuit elements, processing the data values, and deriving the identifier for the semiconductor chip using the processed data values. The identifier identifies the semiconductor chip from other semiconductor chips manufactured using the fabrication process. The circuit elements can be selected from the group of bipolar transistors, MOS transistors, light detecting pixel elements, and memory cells. The chip identification method is particularly useful for identifying image sensor chips where the dark current values or the defective pixel locations can be used as the chip identifier.