The mechanism of dehydrogenation of SiNx:H films

We have developed a novel remote plasma enhanced chemical vapour deposition (RPECVD) process for the deposition of SiNx:H films from hexamethylcyclotrisilazane [SiNH(CH3)(2)](3) in which not all gases are plasma excited. The films grown in this manner do not have any carbon-bonded species. The films contain hydrogen in N-H bonds only. The hydrogen evolution kinetics was studied. It was shown that the rate of dehydrogenation does not depend on the film thickness and depends only on the initial concentration of bonded hydrogen in the film. It was established that the dissociation of N-H bonds is the limiting stage of the dehydrogenation process. An activation energy equal to 60 kJ mol(-1) was determined. This value is lower than the energy of dissociation of N-H bonds. It indicates that the hydrogen evolution process is governed by a cooperative phenomenon proceeding in the network.