PREPARATION AND PROPERTIES OF ALANE DIMETHYLETHYLAMINE, A LIQUID PRECURSOR FOR MOCVD

The properties of AlH3.NMe2Et, DMEAl, have been examined particularly with respect to use as a precursor for the metalorganic chemical vapor deposition (MOCVD) of aluminum-containing layers. An optimal synthesis of DMEAl not involving ether solvents is also described. At ambient temperatures DMEAl is a colorless volatile liquid but has limited thermal stability, slowly decomposition to generate potentially high pressures of hydrogen. No dissociation of the adduct was observed in the infrared spectrum of the vapor at room temperature, but DMEAl does undergo some degree of dissociation during distillation in vacuo, thereby leaving a residue of involatile AlH3. Analysis by differential scanning calorimetry showed that DMEAl should not decompose explosively at elevated temperatures. It does not spontaneously inflame in air unless dropped onto vermiculite. The H-1 NMR spectrum is highly dependent upon concentration.