Ozone Based Atomic Layer Deposition of Hafnium Oxide and Impact of Nitrogen Oxide Species

Abstract

It has recently been reported that nitrogen oxide species (e.g., N2O5, NO2, NO3, and/or N2O) can have an impact on ozone based atomic layer deposition (ALD) of metal oxides when ozone is generated by dielectric barrier discharge (DBD) in O2/N2 mixtures. In this work, we further investigate the effect of the O2/N2 ratio in the DBD for HfO2 ALD using HfCl4 as metal precursor. Using O3 in the absence of nitrogen oxides, uniform HfO2 layers are obtained between 200 and 250 C in a hot wall cross flow reactor. The self-limiting nature of the O3 and HfCl4 reaction is demonstrated at 225 C and the growth-per-cycle is 0.12 nm. At higher temperature, O3 decomposes at the HfO2 coated reactor walls, resulting in a decreasing HfO2 thickness over Si substrates in the direction of the gas flow. Using O3 in combination with nitrogen oxides by DBD in N2/O2 mixtures, we obtained uniform HfO2 layers in the 200–300C temperature range. At 300C, the GPC is 0.14 nm and the HfO2 films show a low impurity content. Both processes produce high quality dielectric layers in Pt gated capacitors. VC 2011 The Electrochemical Society. [DOI: 10.1149/1.3561423] All rights reserved. Manuscript submitted November 18, 2010; revised manuscript received February 1, 2011. Published March 17, 2011. Atomic Layer Deposition (ALD) is a thin film deposition tech-nique with a number of unique capabilities, such as growth contro

Hafnium oxide passivation of InGaAs/InP heterostructure bipolar transistors by electron beam evaporation

“…Moreover, the XRR fitted dielectric total thickness of ~ 13 nm is quite similar to the value previously measured by ellipsometry. Furthermore, the calculated film density of 10.3 g/cm 3 for HfO 2 film is in agreement with values reported in literature [13,[21][22][23]. The effects of the HfO 2 passivation are shown by comparing the electrical characteristics of large area InGaAs/InP HBTs before and after e-beam evaporation.…”

TiO2 thin film patterns prepared by chemical vapor deposition and atomic layer deposition using an atmospheric pressure microplasma printer

“…At low temperatures (<100°C), the GPC of TTIP/O 3 process was reported to be 0.01 nm, and hence we can infer that the role of O 3 during ALD with the microplasma printer at 60°C is negligible. Nitrogen oxides such as NO 2 and NO 3 have been reported to have impact on the growth of different metal oxides during O 3 ‐based ALD when O 3 is generated by DBD; addition of N 2 to the O 2 supply of the DBD (as O 3 generator for ALD) and generation of N x O y species has shown to yield a higher GPC in HfO 2 , ZrO 2 , La 2 O 3 , and a lower GPC in Al 2 O 3 , O 3 ‐based ALD processes . To our knowledge, nitrogen oxides have not been explored as oxidants in ALD of TiO 2 and hence their impact on the ALD growth of TiO 2 is not known.…”

Metal‐Insulator Transition in ALD VO2 Ultrathin Films and Nanoparticles: Morphological Control

“…In TEMAV, V is already present in the desired V 4+ oxidation state, which may facilitate the direct formation of VO 2 during ALD . Furthermore, the choice of the oxidizer is important to obtain uniform, conformal, and high quality ALD films of the desired phase with the right V valence . Previous work using O 3 as oxidizer led to the formation of V 5+ in the as‐deposited films, which required subsequent annealing under reducing conditions to obtain VO 2 …”