Low-temperature growth of nitrogen-doped BeTe and ZnSe/BeTe:N superlattices for delta doping

We propose ZnSe/BeTe:N superlattice (SL) as a new p-type cladding layer with improved p-type dopability, in which nitrogen-doped BeTe (N-doped) layers are inserted into undoped ZnSe layers. We have optimized the growth temperature for ZnSe/BeTe:N SLs. Both equivalent beam pressure (BEP) ratio and growth rate are further optimized in low-temperature growth of BeTe:N layers. The structural properties of BeTe:N layers were analyzed by reflection high-energy electron diffraction and high-resolution X-ray diffraction. Electrical properties were evaluated by the van der Pauw method and capacitance-voltage (C-V) measurements. We achieve the net acceptor concentrations of 1.2 x 10(19) cm(-3) at the growth temperature of 350degreesC, BEP ratio of around 6, and growth rafts of 35 nm/h. (C) 2003 Elsevier Ltd. All rights reserved.