High concentration Zn doping in InP grown by low-pressure metalorganic chemical vapor deposition

High concentration Zn doping in InP grown by low-pressure metalorganic chemical vapor deposition (MOCVD) was investigated in terms of saturated Zn and hole concentrations. A hole concentration of 4.5×10^{1 8} cm^-3 was obtained using the conventional doping source (dimethylzinc). The saturated Zn and hole concentrations were almost independent of growth temperature and PH₃ flow rate. However, the saturated concentrations increased with increasing growth rate. Zn in the epilayer was essentially electrically active. The Zn incorporation saturation and the accompanying rapid diffusion were thought to have originated from the increase of Zn in interstitial sites. A possibility of achieving a heavily Zn-doped layer was demonstrated in terms of the nonequilibrium nature of the MOCVD growth.