Analysis of HfO2 Charge Trapping Layer Characteristics After UV Treatment

The improvement in the charge storage characteristics in a non-volatile memory (NVM) device employing an ultraviolet (UV)-treated hafnium oxide (HfO 2 ) layer as the charge-trapping layer is reported. X-ray photoelectron spectroscopy analysis was performed to characterize the Hf 4f and O 1s peaks. The defect densities corresponding to Hf and O after short-term UV treatment are 24.74% and 14.16%, respectively. The electrical characteristics, such as the interface trap density (D it ), dielectric constant, and flat band voltage (V FB ), of single HfO 2 thin films were determined via capacitance vs voltage (C–V) measurements of the fabricated metal–oxide–semiconductor (MOS) capacitors. Notably, this memory device has a maximum ΔVth of 4.10 V at 15 V, which corresponds to a 33.4% improvement in memory storage characteristics compared to those of an as-deposited HfO 2 thin film-based memory. In addition, the charge retention after 10 years is 80.22%, which is superior to that of the as-deposited case. These results demonstrate the possibility of realizing high-efficiency TFT NVM devices using high-K materials, and are expected to enable further research on semiconductor devices using high-K materials as well as next-generation memory semiconductors using UV treatment.