A new simple transport model is used to describe the dependence of the electrical characteristics of the epitaxial layer on the growth parameters in low‐pressure metalorganic chemical vapor deposition. The important parameters of this model are the mean velocity of the gases and the [V]/[III] ratio. Undoped GaAs epitaxial layers are prepared at various operating pressures. A semi‐empirical correlation relating the reactor pressure and flow rate is established that dictates the operating conditions for a single set of film properties. This enables growth of a material with constant characteristics while pressure can be varied. ©1995 American Institute of Physics.