Efficient doping of nitrogen with high activation ratio into ZnSe using a high-power plasma source

We have developed a high-power (5 kW) rf plasma source for nitrogen doping in ZnSe molecular beam epitaxy. Optical emission spectroscopy shows dominant atomiclike emissions around 800 nm due to excited neutral nitrogen atoms in the high power region and their intensities rapidly increase with increasing the rf power from 1 to 3 kW. The high net acceptor concentration $({\mathrm{N}}_A–{\mathrm{N}}_D)$ of ${\text{1.2×10}}^{18}\hspace{0.5em}{\mathrm{cm}}^{\mathrm{-3}}$ was achieved at the growth temperature of 220 °C and the activation ratio $\mathrm{[(}{\mathrm{N}}_A–{\mathrm{N}}_D\mathrm{)/}\mathrm{N}]$ as high as 60%, which is the highest value so far obtained for ${\mathrm{N}}_A–{\mathrm{N}}_D{\text{∼10}}^{18}\hspace{0.5em}{\mathrm{cm}}^{\mathrm{-3}}.$ Consequently, the PL spectrum showed well-resolved deep donor-acceptor pair emissions even with high ${\mathrm{N}}_A–{\mathrm{N}}_D.$