IETS in MIS Contacts: Towards a Quantum Biomimetic Electronic Nose

Inelastic electron tunneling spectroscopy (IETS) has been used to detect the vibrational modes of molecules and has been proposed as the mechanism of olfaction according to the so-called Vibration Theory. Motivated by the promise of an electronic nose that will be biomimetic - in the sense of the Vibration Theory - we demonstrate here IET spectroscopy of vibrational modes in metal-insulator-semiconductor (MIS) devices consisting of ultrathin HfO
₂
deposited on silicon by Atomic Layer Deposition (ALD). Low-noise IETS measurements at 10K are carried out using second harmonic detection by a standard lock-in procedure. Parallely, a filtering algorithm is applied to the measured I-V data to compute its second derivative. The IETS peaks in the filtered data and experimentally measured lock-in data are compared and are found to be in agreement with each other; as well as with other experimental vibrational energy data measured through IETS or other techniques.