Abstract: A method of fabricating semiconductor devices including the steps of forming a silicon-based dielectric layer containing nitrogen having a concentration that is in a range of a fraction of a percent up to stoichiometric Si.sub.3 N.sub.4 ; and annealing the dielectric layer in a water vapor atmosphere.

Abstract: A method of fabricating a semiconductor structure involving the steps of providing a SiC substrate, treating the SiC substrate with an N.sub.2 O-containing plasma, and forming a dielectric layer on the surface of the pretreated SiC substrate. A semiconductor structure produced by the method above. An apparatus for forming a dielectric layer on a SiC substrate including a deposition chamber in which the SiC substrate is placed, a first valve that connects a first source providing N.sub.2 O to the deposition chamber, a second valve that connects a second source providing reactants that form the dielectric layer to the deposition chamber, an energy source for producing an N.sub.2 O-containing plasma from N.sub.2 O released from the first source by the first valve, and a controller that programs providing power to the energy source and opening and closing the first and second valves into two phases.