Secure chip identification using random threshold voltage variation in a field effect transistor structure as a physically unclonable function

A semiconductor structure comprising:

• one or more gate regions of one or more field effect transistors, the one or more gate regions is above one or more channels;
• a metal gate, the metal gate is separated from the one or more channels by a gate dielectric layer;
• a first high-k material and a second high-k material embedded in the gate dielectric layer, wherein the first high-k material, the second high-k material, and the gate dielectric layer are in direct contact with the one or more channels;
• and
• an interlayer dielectric, the interlayer dielectric surrounding the one or more gate regions.

A semiconductor structure comprising:

• one or more metal gates;
• one or more channels below the one or more metal gates;
• a gate dielectric layer separating the one or more metal gates from the one or more channels;
• and
• a first high-k material and a second high-k material embedded in the gate dielectric layer, wherein the first high-k material, the second high-k material, and the gate dielectric layer are in direct contact with the one or more channels, and wherein the high-k material partially covers a surface of the one or more channels such that at least a portion of the one or more channels remains exposed.