Anti-Tamper Technology for Missile Defense

Period of Performance: 01/25/2013 - 07/26/2013


Phase 1 SBIR

Recipient Firm

Nanohmics, Inc.
6201 E. Oltorf Street Suite 400
Austin, TX 78741
Principal Investigator


Anti-Tamper systems are designed to prevent and/or delay the exploitation of critical technologies. One of the major tools for reverse engineering is x-ray imaging, often used with computer-aided tomography to enable 3-dimensional information gathering of an IC structure. Thus, a device which can be built into the IC, and/or placed on the circuit board, that detects x-rays due to attempts at reverse-engineering is needed. The device would need to be function while in an unpowered state, consuming no or very little power. Nanohmics proposes to design and build a Buried Gate Hafnium oxide threshold X-ray detector (X-AlarmTM) that provides precision dosimetric detection of X-ray fluence with zero power consumption in a micro scale that is compatible with existing semiconductor fabrication techniques. The X-Alarm device will be fabricated similarly to a flash memory bit with a buried charge-storing gate, a control gate, and the drain and source electrodes used for reading out the state. The device will consist of two similar transistors, one using standard silicon dioxide as the gate dielectric and the other using hafnium oxide, which provides not only extremely low leakage current, but also high X-ray interaction cross section, increasing X-ray sensitivity. When sufficient X-ray fluence is incident on the device, electrons liberated by ionization will be recaptured on the buried gate, altering its charge state and shifting the threshold voltage across the readout electrodes, similar to a FET. Due to the higher interaction cross section of the halfnium oxide, that device will undergo a more marked shift in the gate threshold voltage. Comparing the threshold voltage between the reference (SiO2 dielectric) and the active (HfO2 dielectric) will give a measure of the historical total X-ray dose that is independent of temperature. This device will always be operational, independent of the power state of the device and will consume zero power.