Radiation tolerance and defect dynamics of ALD-grown HfTiO (x) -based MOS capacitors

The study of radiation response and reliability of high-k dielectric materials plays a prominent role in Complementary Metal Oxide Semiconductor (CMOS) technology for device applications in nuclear and space electronics. In the present work, radiation effects on Atomic Layer Deposition (ALD)-grown Hafnium Titanium Oxide (HfTiO (x) )-based MOS capacitors have been investigated. HfTiO (x) thin films grown on Si substrates were irradiated with Co-60 gamma radiation across a wide range of doses (100-3 Mrad). The defects in the pristine and gamma-irradiated thin films were examined by Photoluminescence spectroscopy. By using Poole-Frenkel tunnelling mechanisms, the effects of defects on the I-V characteristics of devices have been studied, as a function of radiation dose. Furthermore, the C-V measurements exhibit notable changes in the density of oxide and interface traps in the films. These devices survived gamma irradiation doses of up to 3 Mrad despite minor variations in their electrical properties. Hence, this work demonstrates the radiation tolerance and suitability of HfTiO (x) -based MOS capacitors for applications in radiation environments.