Atomic-layer deposition of Lu2O3

Abstract

Rare earth oxides could represent a valuable alternative to SiO2 in complementary metal–oxide–semiconductor devices. Lu2O3 is proposed because of its predicted thermodynamical stability on silicon and large conduction band offset. We report on the growth by atomic-layer deposition of lutetium oxide films using the dimeric {[C5H4(SiMe3)]2LuCl}2 complex, which has been synthesized for this purpose, and H2O. The films were found to be stoichiometric, with Lu2O3 composition, and amorphous. Annealing in nitrogen at 950°C leads to crystallization in the cubic bixbyite structure. The dielectric constant of the as-grown Lu2O3 layers is 12±1.

X‐ray photoelectron spectroscopy study of energy‐band alignments of Lu2O3 on Ge

“…Two different O 1s components are clearly present: the first one at ¾530 eV is attributed to oxygen in Lu 2 O 3 form, while the second one at ¾533 eV is usually related to the OH groups at the film surface. 10 The Lu 4f spectrum was therefore fitted using a couple of 3 : 4 doublets after Shirley background correction. The Lu 4f doublets related to Lu 2 O 3 (solid lines) and to Lu(OH) 3 (dashed lines) for the 10-nm and for the 3-nm thick samples are reported in Fig.…”

“…All the details about the growth parameters can be found in Ref. 10. A Ge reference sample was prepared by HF cleaning followed by rinsing in deionized water in order to remove the native GeO 2 .…”

Rare-earth oxide thin films for gate dielectrics in microelectronics

“…The list of ALD rare-earth oxide processes (Table 3) [34,81,[85][86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103] already covers all the rare-earth elements [104]. The oxygen precursor most common in ALD processes, H 2 O, does not show chemical activity sufficient for the reaction with ␤-diketonates and films could thus not be obtained using water as the precursor.…”

Atomic Layer Deposition of Praseodymium Aluminum Oxide for Electrical Applications

“…Using ALD, Kukli et 3 and H 2 O. [7] As with other ALD processes developed for lanthanide-based high-k oxides, including lanthanum oxide, yttrium oxide, and lutetium oxide, [8] the ALD of Pr 2 O 3 presented some difficulties in achieving the excellent electrical properties of films made via physical vapor deposition methods. Though ALD was achieved using Pr[N(SiMe 3 ) 2 ] 3 and H 2 O, the ligand removal was not complete.…”