Researchers at NIST have developed a new method to electronically authenticate products before they leave the factory, using a technique called doping. By implanting small clusters of “foreign” atoms just beneath the surface of electronic devices, they create a unique electronic label that can be read by an electronic scanner. This method is simpler, less costly, and requires less equipment than other doping techniques using lasers or ion beams.
The implanted atoms alter the electrical properties of the topmost layer without harming it, creating a unique label that can be read by an electronic scanner. The technique involves using the sharp tip of an atomic force microscope (AFM) probe to implant atoms, which is simpler and less damaging than other methods. The resulting electronic ID is a nanometer-scale version of a QR code for the wafer, with each dopant-modified lattice having a unique impedance depending on the amount and type of dopant.
The study refines the AFM method for inserting dopant atoms, making it easier to test the electronic ID system under real-life conditions. The researchers consider their technique a prototype that will need modification before it can be used in mass production. One possibility is to use the sharp probes of several AFMs working side by side or employ high-pressure rollers to rapidly push dopant atoms coating a computer chip or other device a few nanometers into the device.
Keywords: Atomic Force Microscope, Dopant, Impedance
