Photoluminescence and growth of ZnSe : N using radical species from microwave excited N plasma

We have developed a new epitaxial growth method of ZnSe : N semiconductor films using radical species generated from microwave-excited nitrogen plasma. Excited species in the N plasma have been identified to be N atoms and N_2 molecular radicals using high-resolution optical emission spectroscopies. The growth was carried out onto ZnSe (100) substrates at a temperature of 350℃ under N pressure of 4 Torr. The obtained ZnSe homoepitaxial film shows that the predominant emission at 4.2K is due to the recombination of excitons bound to neutral acceptors (I_1^d line), whereas a donor-acceptor pair emission encompassing N acceptor seems to be extremely weak. Doping process of N acceptors during growth is discussed.