An excess heat from an exothermic reaction of metastable Ar (43P0) and Ar (43P2) atoms with N2molecules at low contents of N2in Ar was found to be responsible for an enhanced thermionic emission, an enhanced production of Ti target vapor, an increased ionization, and consequently for an enhanced deposition rate of TiN films in the radio frequency hollow cathode plasma jet (RHCPJ). This finding emphasizes favorable geometry of hollow cathodes, as well as an important role of metastables in plasma‐assisted processes. ©1995 American Institute of Physics.