A THERMODYNAMIC ANALYSIS OF SELECTIVE-AREA CVD OF TITANIUM NITRIDE COMPOUND BY THE ALTERNATING CYCLIC METHOD

As the first step in investigating the selective area chemical vapor d eposition 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 depositio n via the hydrogen reduction of TiCl4 is followed cyclically by the et ching of spurious nuclei from mask regions via an embedded disproporti onation reaction. The thermodynamic calculations have been set up usin g 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 equi librium constant constraining equations have then been employed as int egrity checks of the outputs of the computer program. In addition, usi ng the first principles approach, solid-vapor solubility curves have b een 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.