Structural Properties of Bi Containing InP Films Explored by Cross-Sectional Scanning

Krammel, C. M.; Koenraad, P. M.; Roy, Mervyn; Maksym, P. A.; Wang, Shumin

doi:10.1007/978-981-13-8078-5_10

Cited by 1 publication

(1 citation statement)

References 35 publications

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“…Various works on bismuthcontaining alloys have also reported the benefits of the bismuth surfactant. [11][12][13][14][15][16][17][18][19][20] However, there are no studies on the use of Bi surfactant in homoepitaxial GaSb thin films. 21,22,51 There are currently two major theories on the microscopic mechanism of this surfactant's suppression 3D-islanding effect.…”

Section: Introductionmentioning

confidence: 99%

Bismuth surfactant enhancement of surface morphology and film quality of MBE-grown GaSb(100) thin films over a wide range of growth temperatures

Menasuta,

Grossklaus,

McElearney

et al. 2024

Journal of Vacuum Science &Amp; Technology A

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We investigate the surface morphologies of two series of homoepitaxial GaSb(100) thin films grown on GaSb(100) substrates by molecular beam epitaxy in a Veeco GENxplor system. The first series was grown at temperatures ranging from 290 to 490°C and serves as a control. The second series was grown using the same growth parameters with bismuth used as a surfactant during growth. We compared the two series to examine the impacts of bismuth over the range of growth temperatures on the GaSb surface morphologies using atomic force microscopy and the film properties using Raman spectroscopy and scanning electron microscopy. High-resolution x-ray diffraction was performed to confirm that bismuth was not incorporated into the films. We found that the morphological evolution of the GaSb series grown without bismuth is consistent with the standard surface nucleation theory and identified the 2D-3D transition temperature as close to 290° C. In contrast, the presence of a Bi surfactant during growth was found to significantly alter the surface morphology and prevent undesired 3D islands at low temperatures. We also observed a preference for hillocks over step morphology at high growth temperatures, antistep bunching effects at intermediate temperatures, and the evolution from step-meandering to mound morphologies at low temperatures. This morphological divergence from the first series indicates that bismuth significantly increases in the 2D Erlich–Schwöebel potential barrier of the atomic terraces, inducing an uphill adatom flux that can smoothen the surface. Our findings demonstrate that bismuth surfactant can improve the surface morphology and film structure of low-temperature grown GaSb. Bismuth surfactant may also improve other homoepitaxial III-V systems grown in nonideal conditions.

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