Guaranteeing that computer chips — which can consist of billions of interconnected transistors — are manufactured without defects is a challenge. It’s also a challenge to determine if a chip is compromised. A new technique would allow companies and other organizations to non-destructively scan chips to ensure that they haven’t been altered and that they are manufactured to design specifications without error.
The new method validates the integrity of computer chips using x-rays. Called ptychographic x-ray laminography, the technique utilizes x-rays from a synchrotron to illuminate a small region of a rotating chip at an angle of 61 degrees (with respect to the normal of the chip plane). The resulting diffraction patterns are measured with a photon-counting detector array. The data are then used to generate high-resolution slice images of the chip, from which 3D renderings are created. Once the 3D image is generated, it can be compared with the original design as a type of forensics to help ensure that chips are manufactured correctly and meet design specifications. The chips have signature features, so it is possible to tell how and where they were manufactured.
The process also allows for reverse-engineering of circuit designs without destroying the chip. Viewing a chip in detail enables non-destructive determination of the chip’s purpose.
The technology could contribute to a certification process to ensure the integrity of chips that are inserted into a computer or in communication hardware used by global businesses and governments.