Ozone‐Based Atomic Layer Deposition of Gd₂O₃ from Tris(isopropyl‐cyclopentadienyl)gadolinium: Growth Characteristics and Surface Chemistry

Abstract

The atomic layer deposition (ALD) of Gd 2 O 3 from tris(isopropyl-cyclopentadienyl) gadolinium (Gd( i PrCp) 3 ) and O 3 is studied as a function of the O 2 /N 2 ratio used to generate O 3 . ALD using O 3 with low N 2 content leads to the formation of a hydroxyl-terminated surface after combustion reactions during O 3 exposure followed by proton transfer and ligand release during the Gd( i PrCp) 3 half cycle. This condition leads to the presence of parasitic chemical vapor deposition (CVD) due to the hygroscopicity of Gd 2 O 3 . By contrast, long O 3 pulses with high N 2 content lead to the dehydroxylation of the surface and to the suppression of both the proton transfer during the Gd( i PrCp) 3 half cycle as well as the parasitic CVD reactions.

Substrate-Dependent Growth Behavior of Atomic-Layer-Deposited Zinc Oxide and Zinc Tin Oxide Thin Films for Thin-Film Transistor Applications

“…They claimed that the molecular oxygen could have an even higher activity toward such a combustion-like reaction than the −OH groups. O 3 is known to have a high combustion-like reaction activity in oxide ALD by producing active O* radical on the oxide film surface. − Therefore, perhaps the higher concentration of the O* radicals on the growing ZnO film surface than −OH species resulted in a highly active ALD reaction and such an exceptionally high GPC. The higher GPC on the Si substrate than that on the SnO 2 substrate might be due to the difference in the film density, as discussed later.…”

Atomic Layer Deposition of Ruthenium Thin Films from (Ethylbenzyl) (1-Ethyl-1,4-cyclohexadienyl) Ru: Process Characteristics, Surface Chemistry, and Film Properties

“…For longer pulses, there was also a clear delay of 2 to 3 s between the beginning of the EBECHRu pulse and the observation of ethylbenzene and/or ethylcyclohexadiene in the gas phase. Since such a delay was not observed for other reaction products using the same setup (see, e.g., Figure a and refs and ), it cannot be ascribed to the limited time response of the QMS system. This indicates that the surface reactions of EBECHRu by ligand release occurred after the activated oxygen had been exhausted by combustion processes.…”

Fabrication of GdxFeyOz films using an atomic layer deposition-type approach

“…Similar growth rates are reported when combined Gd(thd) 3 /O 3 36 although higher growth rates have been reported when using Nbonded Gd precursors and water (1 Å/cycle). 27 It is very likely that the use of O 3 and N-containing ligands can form intermediate NO x and C−O species 37 resulting in a more complex surface reaction mechanism affecting the growth rate. 31 According to this study, the selected Gd 2 O 3 deposition conditions for further studies were selected: T Gd-subl = 135 • C and pressure boost, T dep = 250 • C, 70 sccm N 2 carrier gas flow and ozone as co-reactant.…”