LIQUID-PHASE EPITAXIAL-GROWTH OF ALGAASSB ON GASB

Quaternary AlxGa1-xAsySb1-y (x almost-equal-to 0.37 and 0.47) alloy has been grown on GaSb substrate by liquid phase epitaxy from melts containing X(l)(Al) = 0.02 and 0.03. Satisfactory layers could be obtained at T(G) = 605-degrees-C using small supercooling (DELTAT = 1 - 4-degrees-C) and small As content in the melt (X(l)(As) = 10(-4)). The conditions of growing lattice-matched structures have been theoretically evaluated and experimentally determined. Growth kinetics obey the law: d = K DELTATt 1/2, which is characteristic of a diffusion-limited growth, with K = 0.054 mum degrees-C- 1 s-1/2 for (100) orientation and K = 0.036 mum-degrees-C-1 s-1/2 for the (111)B. Undoped layers are p-type with a residual carrier concentration p almost-equal-to 10(16) cm-3. Photoluminescence measurements at 2 K show excitonic and phonon assisted lines, characteristic of good quality indirect gap material. High doping levels were achieved by Ge doping (p = 10(19) CM-3) and Te doping (n = 2 x 10(18) cm-3).