In this study, a vertical thermal radio frequency (RF)-PECVD reactor is modeled to investigate thermal flow and the deposition rates with various shapes of the showerhead. The showerhead in the chemical vapor deposition (CVD) reactor has the shape of a ring and gases are injected in parallel with the susceptor, which is a rotating disk. In order to achieve the high deposition rates, we have simulated the thermal flow fields in the reactor with several showerhead models. Especially the effects of the number of injection holes and the rotating speed of the susceptor are studied. Using a commercial code, CFD-ACE, which uses finite-volume method (FVM) and SIMPLE algorithm, governing equations have been solved for the pressure, mass-flow rates and temperature distributions in the CVD reactor. With the help of the Nusselt number and Sherwood number, the heat and mass transfers on the susceptor are investigated.