Influence of XeCl excimer laser annealing on the ferroelectric nondoped HfO₂ formation deposited on a Si(100) substrate

Abstract

In this research, we have investigated the effect of excimer laser annealing (ELA) on the ferroelectric nondoped HfO2 (FeND-HfO2) formation deposited on Si(100) substrate. The XeCl (λ: 308 nm) ELA was irradiated as post-deposition annealing (PDA) in the N2 ambient to the 10 nm thick HfO2 deposited by RF-magnetron sputtering without substrate heating. The C-V characteristics of Al/HfO2/p-Si(100) metal/ferroelectrics/Si (MFS) diodes were gradually improved with the energy density of ELS from 170 mJ/cm2 to 270 mJ/cm2 irradiated at 200 Hz for 200 shots although charge-injection type hysteresis of 0.2-0.3 V was remained. The post-metallization annealing (PMA) at 400oC/5 min in N2/4.9%H2 ambient for Al/HfO2/p-Si(100) MFS diodes markedly improved the C-V characteristics, and negligible hysteresis with ideal flat-band voltage (VFB) was realized. The memory window (MW) of 0.42 V was achieved by the program/erase (P/E) operation with the input pulses of +3 V/100 ms and -8 V/100 ms for the MFS diode with ELA energy density of 270 mJ/cm2 at 200 Hz for 200 shots followed by the PMA..