In situ infrared spectroscopy of hafnium oxide growth on hydrogen-terminated silicon surfaces by atomic layer deposition

Abstract

The interface formation between HfO2 and H-terminated Si(111) and Si(100) is studied by in situ infrared absorption spectroscopy during atomic layer deposition using alternating tetrakis-ethylmethylamino hafnium (TEMAH) and deuterium oxide (D2O) pulses. The HfO2 growth is initiated by the reaction of TEMAH with Si–H rather than D2O, and there is no evidence for SiO2 formation at moderate growth temperatures (∼100°C). Although Rutherford backscattering shows a linear increase of Hf coverage, direct observations of Si–H, Si–O–Hf, and HfO2 phonons indicate that five cycles are needed to reach the steady state interface composition of ∼50% reacted sites. The formation of interfacial SiO2 (∼0.7nm) is observed after postdeposition annealing at 700°C in ultrapure nitrogen.

Chemical Bonding, Interfaces, and Defects in Hafnium Oxide∕Germanium Oxynitride Gate Stacks on Ge(100)

“…A shoulder on the O 1s feature of the as-deposited sample (~531.5 eV) can be attributed to either a GeO 2 surface region on the air-exposed oxynitride layer or residual -OH groups incorporated in the ALD-HfO 2 film as a result of the use of the H 2 O oxidant precursor during ALD 16 .…”

Non‐Aqueous Routes to Metal Oxide Thin Films by Atomic Layer Deposition

“…[8] Similar problems occur in other common ALD processes that employ stronger oxidizing agents, such as ozone.…”

Comparison of microstructure and electrical characteristics of sputtering-derived HfGdO/HfTiO and HfTiO/HfGdO gate stacks

“…7(a) shows the FTIR spectra of the as-deposited HfGdO/ HfTiO sample and the HfGdO/HfTiO sample after annealing at 300 1C. Bands observed at 400-650 cm À 1 were assigned to HfO 2 phonons modes [25], and the peaks at around 1108, 1048 and 1033 cm À 1 are assigned to Si-O and M-O-Si (M¼ Hf, Gd) stretching vibrations formed at the high-k/Si interface [26]. It is worth noting that, for the FTIR spectra of the as-deposited HfTiO/ HfGdO sample and the annealed one at 300 1C, two peaks located at around 837 and 936 cm À 1 corresponding to M-O-Si stretching vibrations can be seen clearly.…”