We have succeeded in simultaneously conducting two chemical reactions resulting in the formation of titanium nitride and titanium silicide in well-shaped clearly separated layers as an effect of multipulse excimer laser treatment of a Si wafer with a thin Ti coating in an ambient N2 gas. We demonstrate by a numerical analysis that the parallel evolution of the two reactions in a one-step process is a consequence of the melting of both the Ti coating and of a thick layer of Si bulk in conditions that completely avoided substance expulsion.