As the first step in investigating the selective area chemical vapor deposition of titanium compounds, which are of considerable interest in semiconductor technology, a thermodynamic analysis has been performed for the selective area chemical vapor deposition of titanium nitride, over an extensive temperature, pressure, and composition range, using the alternating cyclic (A.C.) process. In this approach TiN deposition via the hydrogen reduction of TiCl4 is followed cyclically by the etching of spurious nuclei from mask regions via an embedded disproportionation reaction. The thermodynamic calculations have been set up using a first principles anal is, and carried out via the computer program, SOLGASMIX, which is based on the minimization of the system’s Gibbs free energy. The first principles constraining conditions and the equilibrium constant constraining equations have then been employed as integrity checks of the outputs of the computer program. In addition, using the first principles approach, solid-vapor solubility curves have been derived for the cases examined. These calculations have indicated that the selective deposition of TiN by this novel method is feasible and have defined the parameter space in which to conduct the selective area deposition in A.C. fashion.