Growth Mechanism of ZnS and ZnSe Films in Low-Pressure MOCVD

The growth mechanism of ZnS and ZnSe films in low-pressure MOCVD has been studied by observing the effects of the growth conditions on the growth rate of the films. The substrate temperature, flow rate of source materials, pressure in reactor, and [VI]/[II] molar ratio were varied, and the growth rate was found to be strongly affected by the pressure in the reactor as well as other growth conditions. The increase of the growth rate with pressure is attributed to an increase in the sticking coefficient of DMZn (or its complexes) with pressure. Furthermore, a decrease in growth rate at higher substrate temperatures was also attributed to a change in the sticking coefficient. It is shown that the sticking coefficient of DMZn (or its complexes) is an important factor in the MOCVD growth of II-VI compounds.