Structure and formation mechanisms of AlGaAs Vhyphen;groove vertical quantum wells grown by low pressure organometallic chemical vapor deposition

摘要

The structure of AlGaAs vertical quantum well (VQW) structures grown by lowhyphen;pressure organometallic chemical vapor deposition on Vhyphen;grooved GaAs substrates was analyzed as a function of growth temperature and Al mole fraction using transmission electron microscopy and atomic force microscopy (AFM). The lowhyphen;pressure growth yields several, extremely narrow (a few nm wide) branches of Gahyphen;enriched VQWs at the bottom of the grooves. The variation in Al content across the VQW was evaluated by measuring the AlGaAs oxide thickness on a cleaved edge of the structure using AFM in air. The transmission electron microscopy analysis demonstrates that the different VQW branches originate from distinct nanofacets that selfhyphen;order at the bottom of the Vhyphen;groove, probably due to facethyphen;induced segregation of group III species. copy;1996 American Institute of Physics.