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Effect of Substrate Orientation on Phase Separation in Epitaxial GaInAsSb.

DE2004822095

Publication Date	2001
Personal Author	Wang, C. A.; Calawa, D. R.; Vineis, C. J.
Page Count	22
Abstract	The effect of substrate misorientation on phase separation in Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) nominally lattice-matched to GaSb is reported. The layers were grown at 575 C by organometallic vapor phase epitaxy on vicinal (001) GaSb substrates, miscut 2(sup o)(yields) (-111)A, (1-11)B, or (101). Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) (x(approx) 0.1, y(approx) 0.09) layers, which have 300-K photoluminescence (PL) peak emission at(approx)2.1(micro)m, grow step-bunched and exhibit minimal phase separation. The full width at half maximum of 4-K PL spectra is slightly smaller at 7 meV for layers grown on substrates miscut toward (1-11)B compared to 9 meV for layers grown on substrates miscut toward (-1-11)A and (101). Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) layers with higher alloy composition (0.16(le) x(le) 0.19, 0.14(ge) y(le) 0.17), which have 300-K PL peak emission at(approx)2.4(micro)m, have significant phase separation. These layers are characterized by increased lattice constant variations and epitaxial tilt, broad PL spectra with significant band tailing, and strong contrast modulation in transmission electron microscopy. The degree of decomposition depends on substrate miscut direction: Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) layers grown on (001) 2(sup o)(yields) (1-11)B substrates are more homogeneous than those grown on (001) 2(sup o)(yields) (-1-11)A and (001) 2(sup o)(yields) (101) substrates. The results are attributed to the smaller adatom diffusion length on substrates miscut toward (1-11)B.
Keywords	Phase separation(Materials) Substrates Alloys Decomposition Electron microscopy Transmission electron microscopy Vapor phase epitaxy Modulation Photoluminescence Diffusion lenght Orientation Spectra
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lockheed Martin Electronics Labs., Syracuse, NY.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200418

Effect of Substrate Orientation on Phase Separation in Epitaxial GaInAsSb.

Effect of Substrate Orientation on Phase Separation in Epitaxial GaInAsSb.
DE2004822095

Publication Date	2001
Personal Author	Wang, C. A.; Calawa, D. R.; Vineis, C. J.
Page Count	22
Abstract	The effect of substrate misorientation on phase separation in Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) nominally lattice-matched to GaSb is reported. The layers were grown at 575 C by organometallic vapor phase epitaxy on vicinal (001) GaSb substrates, miscut 2(sup o)(yields) (-111)A, (1-11)B, or (101). Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) (x(approx) 0.1, y(approx) 0.09) layers, which have 300-K photoluminescence (PL) peak emission at(approx)2.1(micro)m, grow step-bunched and exhibit minimal phase separation. The full width at half maximum of 4-K PL spectra is slightly smaller at 7 meV for layers grown on substrates miscut toward (1-11)B compared to 9 meV for layers grown on substrates miscut toward (-1-11)A and (101). Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) layers with higher alloy composition (0.16(le) x(le) 0.19, 0.14(ge) y(le) 0.17), which have 300-K PL peak emission at(approx)2.4(micro)m, have significant phase separation. These layers are characterized by increased lattice constant variations and epitaxial tilt, broad PL spectra with significant band tailing, and strong contrast modulation in transmission electron microscopy. The degree of decomposition depends on substrate miscut direction: Ga(sub 1-x)In(sub x)As(sub y)Sb(sub 1-y) layers grown on (001) 2(sup o)(yields) (1-11)B substrates are more homogeneous than those grown on (001) 2(sup o)(yields) (-1-11)A and (001) 2(sup o)(yields) (101) substrates. The results are attributed to the smaller adatom diffusion length on substrates miscut toward (1-11)B.
Keywords	Phase separation(Materials) Substrates Alloys Decomposition Electron microscopy Transmission electron microscopy Vapor phase epitaxy Modulation Photoluminescence Diffusion lenght Orientation Spectra
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lockheed Martin Electronics Labs., Syracuse, NY.; Department of Energy, Washington, DC.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200418