The solid source MOCVD technique1,2, employing a single powder vaporization source composed of mixed beta-diketonate metalorganic compounds, has been used to grow thin films of a variety of electro-optic materials, including lithium niobate, strontium barium niobate, and potassium niobate. Results for potassium niobate films are quite preliminary, but indicate that a volatile potassium organometallic source can be synthesized which is useful for growing potassium niobate by MOCVD. High quality single phase (001) oriented strontium barium niobate films have been deposited which exhibit waveguiding behavior. The most extensive work has been done on lithium niobate, which has been deposited epitaxially on a variety of substrates. Oriented z-axis (001) films have been grown on c-axis sapphire with and without a (111) oriented platinum base electrode and on a bulk grown lithium niobate substrate. Films grown directly on c-axis sapphire at 700 C exhibit x-ray rocking curve linewidths as low as.044 degrees, nearly perfect in-plane orientation as determined by x-ray phi scans, and peak-to-peak surface roughness less than 40 Å. Optical waveguiding has been demonstrated by a single prism coupling technique on similar films 1175 – 2000 Å thick grown at 500 C, with optical losses of approximately 2 db/cm at 632.8 nm measured over 3.5 cm long films. Polarization vs. electric field measurements on 1100 Å thick films grown on platinum show a hysteresis loop indicating ferroelectric behavior.

Bismuth-substituted yttrium iron garnet, BixY1−xFe5O12 thin films have been epitaxially grown on a Gd3Ga5O12 (111) substrate at 750°C under reduced pressure (6 Torr), with a deposition rate of 20∼50nm·min−1 by MOCVD. The maximum value of Faraday rotation was −7.5×104deg·cm−1at a Bi-content of 2.5 atoms per formula unit. The Figure of unit was 14.30 deg., which is significantly larger than that obtained by sputtering. On the other hand, cerium-substituted films could not be obtained even at elevated temperatures, 900°C.

A review is presented of recent advances in the metal-organic chemical vapor deposition (MOCVD) of thin films of group III-chalcogenides. The deposition of thermodynamic phases of composition ME and M2E3 (M = Ga, In; E = S, Se. Te) will be presented. Also included is a discussion of the development of molecular control over the structure of deposited films and the atmospheric pressure MOCVD growth of the high pressure phase of InS and a meta-stable cubic phase of GaS.

Vanadium oxide thin films were grown on glass substrates by atmospheric pressure chemical vapor deposition (APCVD) from the reaction of vanadium(IV) chloride with isopropanol and t-butanol. Films were deposited in the temperature range 250 to 450°C. The as-deposited films were a dark greenish color consistent with formation of a lower oxide of vanadium. Annealing a film deposited on Corning 7059 glass in air converted the material to a yellow film. X-ray diffraction of the yellow film revealed the presence of V2O5. Optical spectra of the films are presented. Glass substrates previously coated with conductive fluorine doped tin oxide were coated with V2O5 and evaluated for electrochromic activity.

Sequential surface chemical reactions for the controlled deposition of Al2O3 films were studied using transmission Fourier transform infrared spectroscopy (FTIR). Experiments were performed in situ in an ultrahigh vacuum UHV chamber using high surface area alumina membranes. Trimethylaluminum [Al(CH3)3] (TMA) and H2O vapor were employed sequentially in an ABAB... binary fashion to achieve atomic layer controlled growth. An optimal Al2O3 growth procedure was established that employed TMA/H2O exposures at .3 Torr and 500 K. The experiments revealed that each reaction was self-terminating and atomic layer controlled growth was dictated by the surface chemistry. The controlled deposition of Al2O3 may be employed on silicon surfaces for the formation of high dielectric gate and passivation layers.

CeO2 overlayers up to 360 nm thick were deposited on Si(100) substrates in a flowtype ALE reactor from Ce(thd)4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedione) precursor and ozone. The growth rate was studied as a function of deposition and source temperatures, reactor pressure and pulse durations. The films were characterized for crystallinity, thickness and composition by using XRD, profilometry, XRF, RBS, XPS and SIMS techniques. Films deposited at 375 °C showed a preferential (110) orientation while at 425 °C they were (111) preferentially oriented. Due to the steric hindrance caused by the bulky precursor the growth rate was only 0.4 Å/cycle.

Coordination compounds of alkaline-earth metals with simple monodentate ligands were mentioned in the literature as early as 1820, when Faraday reported ‘metal-ammonias’.[1] The number of heavy alkaline earth element coordination compounds remained limited for many years, however, as it was thought to be unlikely for the large earth alkaline cations to form such complexes. In 1967 Pedersen discovered that cyclic oligoethers (crown ethers) can serve as suitable ligands for divalent alkaline earth cations.[2] His findings were extended a few years later by Lehn who found that macrobicyclic multidentate ligands (cryptands) are efficient ligands for alkaline earth cations.[3] In each of these examples, the primary mode of metal-ligand interaction is electrostatic in origin. These examples demonstrate the lack of well-defined covalent bonding for Ca, Sr and Ba compounds. In the 25 years which have passed since Pedersen's seminal discovery, a large number of coordination compounds containing alkaline earth metals have been synthesized. In recent years, the emphasis has shifted towards the preparation of group 2 element-containing compounds which potentially can be used as precursors in the preparation of metal oxides by chemical vapor deposition [4–8]. In light of the general agreement that no “perfect” barium source presently exists for OMVPE purposes, this article will focus on general themes in group 2 element chemistry and, where relevant, correlate those themes within an integrated approach to design of new compounds of greater potential utilization for the preparation of electronic materials in thin film form.