Boron Nitride Films Prepared by MOCVD

In this article, the results obtained on films deposited by the metalorganic chemical vapor deposition (MOCVD) method using monomethylhydrazine (CH3N2H3, MMH) as a nitrogen source are described. A general atmospheric CVD apparatus with a fused quartz reaction tube and an external heating furnace are used. Experimental conditions are as follows: growth temperature range, 400-1200?C; MMH flow rate range, 0.1-8.0 ml/min; triethylboron (TEB) flow rate, 1.0 ml/min; MMH/TEB range, 0.1-8.0. Boron nitride characteristic spectra are observed in the temperature range 400 to 1100?C. The composition (N/B) of the films deposited at 1000?C increases steeply from N/B=0.01 at MMH/TEB=0.1 to 0.69 at 0.2, and then stoichiometric boron nitride deposits over 1.0 of MMH/TEB. The crystal structure of the films is interesting at present, but the crystallinity is inferior to that obtained when ammonia is used as a nitrogen source. It will be influenced considerably by the electronic configuration based on the molecular structure of methylhydrazine. When methylhydrazine is used, we expect to grow the films at a lower deposition temperature. Until now, however, no particular change in the deposition temperature has been recognized