Analysis of twin defects in GaAs(111)B molecular beam epitaxy growth

Abstract

The formation of twin is common during GaAs(111) and GaN(0001) molecular beam epitaxy (MBE) metalorganic chemical vapor deposition growth. A stacking fault in the zinc-blende (ZB)(111) direction can be described as an insertion of one monolayer of wurtzite structure, sandwiched between two ZB structures that have been rotated 60° along the growth direction. GaAs(111)A/B MBE growth within typical growth temperature regimes is complicated by the formation of pyramidal structures and 60° rotated twins, which are caused by faceting and stacking fault formation. Although previous studies have revealed much about the structure of these twins, a well-established simple nondestructive characterization method which allows the measurement of total aerial density of the twins does not exist at present. In this article, the twin density of AlGaAs layers grown on 1° miscut GaAs(111)B substrates has been measured using high resolution x-ray diffraction, and characterized with a combination of Nomarski microscopy, atomic force microscopy, and transmission electron microscopy. These comparisons permit the relationship between the aerial twin density and the growth condition to be determined quantitatively.

Structure ofGaAs(1¯1¯1¯)under Ga-rich cond

“…Interestingly, the faults become less prevalent in films grown under the Garich conditions that stabilize the ͱ 19ϫ ͱ 19 reconstruction. [13][14][15] A similar trend is found for the initial structures of GaAs nanowires grown by using masks ͑selective-area growth͒. 16 The reconstruction may thus be a key to controlling stacking faults in GaAs films and nanowires.…”

“…This is qualitatively consistent with the experimentally observed trends. [13][14][15][16] Although this simple argument neglects detailed growth processes and the distinction between nanowires and films, it illustrates how the reconstruction may suppress stacking faults in GaAs.…”

Laterally Overgrown GaN on Patterned GaAs (001) Substrates by MOVPE

“…These relationships are the same as those between hexagonal and cubic structures that differ only in the stacking sequence of the close-packed planes. Due to the structural similarities [18] between the c-GaN (111) Conclusions In summary, the lateral overgrowth of both h-GaN and c-GaN films was successfully performed on stripe-patterned GaAs (001) substrates using SiO 2 mask as well as SiN x mask by MOVPE. The conventional TEM images and SAD patterns showed that h-GaN was considerably constructed along only (111) B facets in all samples, regardless of the different mask stripe orientations ([110] and [1 1 10] directions).…”

Effect of rapid thermal annealing on Zn1‐xCdxO layers grown by radio‐frequency magnetron co‐sputtering

“…Also, the x=0.13 peak showed the mixed crystalline as well as a wide FWHM value. It suggests that this cause is related to the stacking faults due to the excess insertion of the cubic CdO (111) in the hexagonal ZnO (0002) at the growth temperature of 400 o C. Due to the structural similarity between the cubic (111) and hexagonal (0001) surfaces, the hexagonal ZnO can be easily reconstructed along the (111) facet of the cubic CdO with increasing the Cd flux [21]. Therefore, it is suggested that it can act as the cause of deterioration of the crystallinity of x=0.13 specimens.…”