Effects of Processing Parameters in the MOCVD Growth of Nanostructured Lanthanum Trifluoride and Oxyfluoride Thin Films

Abstract

Using metal-organic (MO)CVD, lanthanum trifluoride (LaF 3 ) and oxyfluoride (LaOF) films are deposited on Si(100), glass, and quartz from a La(hfa) 3 diglyme single-source precursor. The films are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). They are found to be crystalline with a high degree of fiber texture even when deposited on glass or quartz substrates. The SEM indicates very homogeneous surfaces with grain dimensions decreasing upon increasing the deposition temperature and the oxygen flow. The AFM data indicate a very smooth surface with a root mean square (rms) roughness of 0.96 nm for films deposited at high temperature/high oxygen flow.

MOCVD Fabrication of Magnesium Fluoride Films: Effects of Deposition Parameters on Structure and Morphology

“…They slightly grow and give rise to coalesced grains that, at the highest oxygen flow, form very smooth and homogeneous surfaces. [33] In regard to the crystalline quality, this is actually slightly affected by the oxygen flow, being the XRD patterns (Fig. 8) similar to those obtained under lower oxygen flow (Fig.…”

“…This is due to the different origin of grain formation; in the former case the grains are large because the growth prevails over a poor nucleation, while in the latter case the homogeneous formation of large grains may be related to the high mobility of atoms on the surface due to the high deposition temperature. [33] Finally, the effect of the O 2 reactive gas flow has been explored, upon keeping constant the deposition tempera- ture at 400 8C, at two different vaporization temperatures (T vap ¼ 75 8C and T vap ¼ 100 8C). There is evidence that oxygen flow plays a crucial role in determining the film morphology.…”

Atomic Layer Deposition of LaF3 Thin Films using La(thd)3 and TiF4 as Precursors

“…[14,15] The most often used techniques for depositing LaF 3 thin films have been physical vapor deposition (PVD) methods, e.g., electron-beam evaporation (EBE), [4,11,[16][17][18][19][20][21][22] ion-assisted deposition, [5,7,13,23] thermal evaporation, [3,[6][7][8]12,16,18,[24][25][26][27][28][29][30][31][32][33][34] ionbeam sputtering, [7,18,28] radio frequency magnetron sputtering, [35,36] and molecular beam epitaxy. [37][38][39][40][41] Only a few CVD methods have been used for depositing LaF 3 thin films, i.e., pyrolysis of a single source precursor La(hfa) 3 diglyme complex (hfa ¼ hexafluoroacetylacetonate), [42] or by using HF or NF 3 as a fluorinating agent. [43] Atomic layer deposition (ALD), a special variant of the CVD method, is based on the film growth through alternate saturative surface reactions.…”

Synthesis and characterization of highly luminescent EuOF nanoceramics by using prepared Eu(FOD)3 nanoparticles via sublimation method as precursor

“…The various methods have been developed for the synthesis of lanthanium oxyfluorides (LnOF) such as: sol-gel [13], chemical vapor deposition (CVD) [14], co-decomposing the lanthanide trifluoroacetate precursors (Ln(CF3COO) 3 ) in oleic acid/oleylamine [15], precipitation [16], and solid-state reaction [17].…”