A simple and reproducible process for the open‐tube diffusion of zinc from (ZnO)x(SiO2)1−xsource films into GaAs, Al0.2Ga0.8As and GaAs0.6P0.4is reported. (ZnO)x(SiO2)1−xfilms were deposited onto compound semiconductor substrates by metalorganic chemical vapor deposition. A capping layer of SiO2was deposited on top of the source films. The diffusions were performed in flowing nitrogen at 650 °C. Diffusion depths from 0.2 &mgr;m to several micrometers were readily achieved. The diffusion front inn‐type substrates is abrupt and the average hole concentration for diffused layers in GaAs is approximately 8 × 1019/cm3. The dependence of the diffusion depth on the source film composition (x=0.04–x=1.00) is presented. The dependence of the diffusion depth on the source film thickness and the SiO2cap layer thickness is also reported.