Abstract: A method of controlling the relative amounts of silicon dopant inside and outside of an enhanced growth region on an indium phosphide substrate using a metalorganic chemical vapor deposition (MOCVD) process. The method includes the steps of positioning the indium phosphide substrate in a reactor chamber, and defining an enhanced growth region on the substrate by depositing a dielectric mask on the substrate. The indium phosphide substrate is heated to a growth temperature of between about 600 and 630° C., and the pressure in the reactor chamber is adjusted to between about 40 and 80 Torr. A first gas contains a metalorganic compound comprising indium and a hydrogen carrier gas flow of between about 12 and 16 liters/minute, and a second gas containing a phosphide and a doping gas containing a silicon dopant at a flow rate of between are introduced into the reactor chamber.