Semi-insulating cobalt doped indium phosphide grown by MOCVD

Abstract

Cobalt-doped semi-insulating epitaxial InP layers have been grown for the first time by low pressure metalorganic chemical vapor deposition (LPMOCVD). Cobaltnitrosyltricarbonyl (CNT) was used as the dopant source. LPMOCVD process variables have been identified which produce semi-insulating InP:Co (ϱ≈105ωcm) with featureless surface morphology and layer thickness uniformity better than ±5% over 9 cm2 substrates. SIMS depth profiles for InP:Co and similarly grown InP:Fe indicate variation of the transition metal impurity concentration with depth and for the particular growth conditions examined, an order of magnitude less average Co concentration than Fe. Finally, performance characteristics of early V-groove buried crescent (BC) lasers incorporating such LPMOCVD grown semi-insulating InP:Co as current blocking layers are summarized. These lasers exhibit CW threshold current as low as 8 ma at room temperature and high temperature operation up to 100 ° C.