Ion composition of a multicomponent beam plasma formed by electron‐beam evaporation of a boron‐containing target in medium vacuum

Thin boron and boron nitride films are applied in microelectronics due to their high hardness and strength, and low electrical conductivity. However, methods for fabrication of such films are limited. One promising method is electron‐beam evaporation of a boron‐containing target to form a boron‐containing plasma. In this study, we describe our investigations of the ion mass‐to‐charge composition of the multicomponent plasma generated by heating and evaporation of boron or boron nitride targets by a continuous electron beam in a helium or nitrogen atmosphere at medium vacuum pressure (about 10 Pa). We show that at beam power sufficient for intense evaporation of the boron target, there is an increase in the mass fraction of boron ions in the plasma. For the case of evaporation of a boron nitride target, the deposited coating contains both boron and nitrogen, implying incomplete dissociation of boron nitride molecules in the evaporation process. The results of our study demonstrate the utility of electron‐beam evaporation of high melting point binary compounds in medium vacuum for coating deposition. The fraction of the boron isotopes ions in a multi‐component plasma, formed by an electron‐beam evaporation of boron target in nitrogen at medium (5 Pa) vacuum, increases with the growth of e‐beam power. This fact clearly demonstrates the flexibility of the e‐beam method to provide the control of the coating composition by means of the electron beam power, gas pressure and gas composition.