The effect of thermal annealing on nitrogen-doped ZnSe grown by molecu
lar beam epitaxy has been investigated as a function of nitrogen conce
ntration. It was found that thermal stability of the nitrogen accepter
s in highly nitrogen-doped ZnSe markedly degraded. Furthermore, in ord
er to avoid significant decreases in net acceptor concentration by the
rmal annealing, the nitrogen concentration should be kept within the r
egion of high electrical activity, that is below 1x10(18) cm(-3).