Nitrogen-doped ZnSe with selenium-rich growth by low-pressure organometallic chemical vapor deposition

Abstract

A high-quality nitrogen-doped p-type ZnSe epilayer on (100) GaAs substrate was obtained under selenium-rich growth conditions by low-pressure organometallic chemical vapor deposition. Ammonia was used as the dopant source. The resistivity (0.5 Ω cm) and the free-carrier concentration (p=8.8×1017 cm−3) of as-grown ZnSe:N were derived from Hall measurements. With selenium-rich growth conditions, we can reduce the concentration of compensation defects (VSe-Zn-NSe which acts as a donor in ZnSe). Nitrogen is found to incorporate in ZnSe as a shallow level, which is examined by the dependence of free-to-acceptor emission on the NH3/H2Se molar ratio. The carrier concentration of as-grown ZnSe:N seems to change insignificantly within a wide range of growth temperatures. That is thought to be useful for device fabrication due to uniformity considerations.

Behaviors of group Va elements in ZnSe

“…The experimental process and estimating method in detail can be found in Refs. [6,15,16]. Table 1 summarizes the ionization energies of N, P, Sb and Bi as substitution acceptors and the deep donor complexes in ZnSe.…”