Implanted atoms create unique ID to authenticate electronics

Researchers at the National Institute of Standards and Technology (NIST) in the US have developed a method that could be used to authenticate electronic components at any point in the supply chain.

The low-cost process relies on creating unique and non-duplicable identification tags by altering the electronic structure of silicon.

These tags could be embedded into a device during the manufacturing process and easily authenticated by anyone receiving the device, ensuring a secure supply chain for components in critical systems, according to the team.

The scientists employed a well-known technique called doping, in which small clusters of 'foreign' atoms of a different element from those in the device to be labelled are implanted just beneath the surface – in this case aluminium atoms embedded in a silicon lattice in a random pattern.

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.

Using doping to create electronic tags for devices is not a new idea. However, the NIST technique – which uses the sharp tip of an atomic force microscope (AFM) probe to implant atoms – is simpler, less costly and requires less equipment than other doping techniques using lasers or a beam of ions, according to NIST researcher Yaw Obeng.

"We're putting a sticker on every device, except that the sticker is electronic and no two are identical because in each case the amount and pattern of the dopant atoms is different," said Obeng, who also noted that the technology is less damaging than other methods.

When a scanner directs a beam of radio waves at the device, the electrically altered lattices respond by emitting a unique radio frequency corresponding to their impedance.

Counterfeit devices could be easily identified because they would not respond to the scanner in the same way, although the researchers not the technique needs refinement before it will be ready for use at scale.

The work was presented at International Conference on IC Design and Technology in Dresden, Germany, last week.