The first monomeric, volatile bis‐azide single‐source precursor to Gallium nitride thin films

Abstract

gas-phase precursor reaction, have been reported. ["] In our experiments, relatively high substrate temperatures were chosen (600-650 "C) to accommodate the higher decomposition temperature of the other precursors. These results indicated that, although the films were depleted in Ce, empirical relationships may be established to allow control of deposit composition by the solution composition. Such relationships are very complex, however, and much more experimental work will be needed before definitive predictive relationships can be given.For use as practical 02-selective membranes, CVD deposits such as the one depicted in Figure 3 must be defect free, in addition to possessing desirable oxygen transport properties. The oxygen transport properties may be characterized by conductivity measurements or by direct oxygen permeation measurements at high temperature. The membrane layer must be essentially leak (defect) free before meaningful oxygen permeation measurements can be done. The doped, stabilized ZrOz membranes fabricated thus far have had rather high leakage rates. We believe this is partially due to the relatively large pore size and nonuniform surface of the porous substrates, which may make complete pore blockage difficult to achieve. Unfortunately, there are very limited choices for porous supports available commercially. We are therefore investigating support surface modifications to make the surface more planar and reduce the pore size, as well as investigating reducedpressure deposition more closely.In summary, CeOz-doped Y203.stabilized Zr02 films have been deposited onto porous substrates at atmospheric and reduced pressures by AACVD using a single precursor solution of metal tmhd precursors. Single-phase CeOzdoped stabilized cubic ZrOz was obtained as-deposited over a range of compositions. Reduced-pressure deposition (-10 torr) resulted in a more uniform deposit morphology, and lower C incorporation due to higher relative 0 2 content in the vapor mixture. Preliminary characterization indicates that the deposit and precursor solution compositions differ, but that empirical relationships between solution and film compositions can be employed to control the composition of the deposit. Leak-tight layers for membrane applications have not yet been produced. This is a challenging task requiring good control of the support structure, as well as the CVD process. In general, AACVD is a useful technique for deposition of multicomponent metal oxide films, particularly when precursors with poor volatility or thermal stability are involved.The group-I11 nitrides AlN, GaN, and InN are candidates for applications as light-emitting diodes and semiconductor lasers operating at short wavelengths of the optical spectrum. These materials have several advantages, including direct bandgaps for high efficiency in optoelectronic devices, high radiation hardness, and complete solubility among the binary compounds. Hexagonal CaN is of particular interest because of its potential as a wide-bandgap (3.45 eV) electroluminesc...

A Study of Bisazido(dimethylamino-propyl)gallium as a Precursor for the OMVPE of Gallium Nitride Thin Films in a Cold-Wall Reactor System under Reduced Pressure

“…Our previously reported PL data on GaN films showed only the low energy defect luminescence, not the band edge luminescence. [25] These films were grown in a simple hot-wall system in vacuo, without nitridated sapphire or the aid of GaN buffer layers, using a batch of relatively impure BAZIGA (melting point of ±28 C, as compared to 35 C for the BAZIGA used for the experiments described in this paper). To the best of our knowledge, there is no other report in the literature on a GaN material grown with any SMP in the absence of additional N sources (e.g., ammonia) giving reference to PL data of the GaN film.…”

Materials Chemistry of Group 13 Nitrides

“…However, the compounds M(N 3 ) 3 are extremely dangerous, energetic, and explosive materials (temperature and shock sensitive), as well as being non-volatile solids [119]. In 1989 Beach et al [120] and Gladfelter et al [121] [122,123], Kouvetakis et al [124][125][126] and ourselves [127][128][129][130][131][132][133][134][135] who have independently start to study the coordination chemistry of group 13 azides in more detail, with the aim of developing a suitable chemistry for azide precursors for OMVPE of the group 13 nitrides. A significant problem associated with SMPs such as…”

“…Single molecule precursors for group 13 nitrides have been designed and developed by many research groups on the basis of volatile group 13 amide, azide and hydrazide compounds, and these have been investigated in MOCVD studies [151,152] [155]. Solution synthesis of colloidal GaN at low temperatures using azide-based precursors was reported [156].…”

An Efficient Chemical Solution Deposition Method for Epitaxial Gallium Nitride Layers Using a Single-Molecule Precursor

“…[14] The effective and easier synthesis of the ligand Li[(CH 2 ) 3 N(C 2 H 5 ) 2 ] (overall yield 72 % for 1) compared to the ligand Li[(CH 2 ) 3 N(CH 3 ) 2 ] (overall yield 55 % for 2) encouraged us to select 1 rather than 2 for the reported CSD studies. Compound 1 crystallizes at room temperature (20 C) (m.p.…”

“…Most of the recent research work on SMPs for group-13 nitrides has concentrated on azide derivatives. [9] Nanocrystalline powders, [10] colloidal quantum dots, [11] nanowhiskers, [12] photonic composites, [13] and OMVPE [14] of nitrides have all been reported employing SMPs.…”