TY - JOUR

T1 - Lattice parameter determination of a strained area of an InAs layer on a GaAs substrate using CBED

AU - Akaogi, Takayuki

AU - Tsuda, Kenji

AU - Terauchi, Masami

AU - Tanaka, Michiyoshi

PY - 2004

Y1 - 2004

N2 - All the six lattice parameters (a, b, c, α, β and γ) of a strained area of an InAs layer grown on a GaAs substrate were determined without any assumption of the crystal lattice symmetry from the higher-order Laue zone (HOLZ) lines appearing in one convergent-beam electron diffraction (CBED) pattern. The analysis was performed with three steps. Firstly, the parameters a and β were determined from the deviations of the HOLZ lines from the mirror symmetry perpendicular to the [001] direction. Secondly, the parameter c was determined from the distance between the intersections of the HOLZ lines, which have the same h and k indices but different l indices. Finally, the parameters a, b and γ were determined simultaneously from several distances between the intersections of the HOLZ lines. The lattice parameters determined for the strained area were a = 0.611(2) nm, b = 0.615(1) nm, c = 0.6119(7) nm, α = 89.5(1)°, β = 89.0(2)° and γ = 89.1(2)°. This result implies that the cubic lattice of InAs is elongated approximately in the [111] direction and the exact lattice symmetry is triclinic. The same analysis procedure was applied to another two specimen areas. It was found that the areas have orthorhombic distortions with lattice parameters a = 0.607(2) nm, b = 0.604(1) nm and c = 0.6085(7) nm for one area, and with a = 0.607(2) nm, b = 0.605(1) nm and c = 0.6065(7) nm for the other area. It is should be emphasized that the present analysis of lattice distortions is immediately applicable to the other semiconductors, such as Si, SiGe or GaAs layers, without assuming any crystal system.

AB - All the six lattice parameters (a, b, c, α, β and γ) of a strained area of an InAs layer grown on a GaAs substrate were determined without any assumption of the crystal lattice symmetry from the higher-order Laue zone (HOLZ) lines appearing in one convergent-beam electron diffraction (CBED) pattern. The analysis was performed with three steps. Firstly, the parameters a and β were determined from the deviations of the HOLZ lines from the mirror symmetry perpendicular to the [001] direction. Secondly, the parameter c was determined from the distance between the intersections of the HOLZ lines, which have the same h and k indices but different l indices. Finally, the parameters a, b and γ were determined simultaneously from several distances between the intersections of the HOLZ lines. The lattice parameters determined for the strained area were a = 0.611(2) nm, b = 0.615(1) nm, c = 0.6119(7) nm, α = 89.5(1)°, β = 89.0(2)° and γ = 89.1(2)°. This result implies that the cubic lattice of InAs is elongated approximately in the [111] direction and the exact lattice symmetry is triclinic. The same analysis procedure was applied to another two specimen areas. It was found that the areas have orthorhombic distortions with lattice parameters a = 0.607(2) nm, b = 0.604(1) nm and c = 0.6085(7) nm for one area, and with a = 0.607(2) nm, b = 0.605(1) nm and c = 0.6065(7) nm for the other area. It is should be emphasized that the present analysis of lattice distortions is immediately applicable to the other semiconductors, such as Si, SiGe or GaAs layers, without assuming any crystal system.

KW - Convergent-beam electron diffraction

KW - InAs

KW - Lattice parameter determination

KW - Lattice strain

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U2 - 10.1093/jmicro/53.1.11

DO - 10.1093/jmicro/53.1.11

M3 - Article

C2 - 15077894

AN - SCOPUS:1642405491

SN - 0022-0744

VL - 53

SP - 11

EP - 19

JO - Journal of Electron Microscopy

JF - Journal of Electron Microscopy

IS - 1

ER -