ANOMALOUS DIFFUSION OF ISOELECTRONIC ANTIMONY IMPLANT INDUCED DEFECTSIN GAAS-ALGAAS MULTIQUANTUM-WELL STRUCTURES

We present here evidence on the deep diffusion of isoelectronic Sb imp lant induced defects in thick GaAs-AlGaAs multiquantum well structures (MQW) to depths as far as approximately 30 times the implant projecte d range (R(p). This observation has been confirmed by performing low t emperature photoluminescence depth scanning measurements and cross-sec tional transmission electron microscopy (XTEM) analysis on room temper ature Sb implanted thick MQW samples. An explanation based on the isoe lectronic nature of Sb and its substitution on As site (Sb(As)) has be en proposed to understand the anomalous diffusion of defects during im plant and their contribution to Al/Ga disordering during post-implant annealing.