CHEMICAL-VAPOR-DEPOSITION OF ALUMINUM FROM DIMETHYLALUMINUMHYDRIDE (DMAH) - CHARACTERISTICS OF DMAH VAPORIZATION AND AL GROWTH-KINETICS

The metallization process for the chemical vapor deposition of aluminum from dimethylaluminumhydride [(Al(CH3)(2)H, DMAH)] has received considerable attention. In this article, the authors discuss the vaporization of DMAH, Al deposition kinetics, selective growth, and film properties. Although DMAH has extremely high viscosity (about 4000 cP), it was found by metering the DMAH flow rate that DMAH can be vaporized while maintaining a high efficiency of 80%-100% of the theoretical flow rate, even with the conventional bubbling method. The film growth rate followed the Arrhenius law at lower temperatures (<250-270 degrees C, depending on the partial pressure of DMAH). The maximum growth rate attained was about 1160 nm/min at 350 degrees C. In the surface-reactian-controlled region, Al was deposited selectively on metal substrates. The origin of selectivity is discussed from the viewpoint of surface chemical conditions. The Al deposition rate was independent of the deposition area, which is discussed in terms of the supply and consumption balance of Al. (C) 1995 American Vacuum Society.