Preparation of ZnSe thin films by metalorganic chemical vapor deposition using NF3

The growth of ZnSe films was performed at 672 similar to 723 K by metalorganic chemical vapor deposition using an atmospheric-pressure, rf-heated and horizontal reactor. Diethylzinc (DEZn) and diethylselenide (DESe) as source materials were fed by H-2 gas with the [VI]/[II] ratio on a semi-insulation GaAs(100) substrate. Nitrogen trifluoride (NF3) was used as co-reactant. The growth rate estimated by the profile meter indicates that NF3 drastically enhanced the growth rate at the flux (f(NF3)) of about 0.3 mu mol/s. The increased growth rate might be due to some chain reaction of dealkylation from DESe with NF3. Photoluminescence of the ZnSe films was measured at 77 K by using a He-Cd laser for excitation. For all the films grown at f(NF3) < 0.3 mu mol/s, the donor-acceptor (D-A) pair emission was observed in the spectra, which corresponds to that reported on the nitrogen-doped p-type ZnSe. The result indicates that the nitrogen atoms from NF3 might be incorporated into the grown films. At f(NF3) >0.3 mu mol/s, the emission peak broadened in the region of 2.4-2.6 eV.