The Effect of Growth Temperature and V/III Flux Ratio of MOCVD Antimony Based Semiconductors on Growth Rate and Surface Morphology

Ari Handono Ramelan,Sayekti Wahyuningsih,Ewa M Goldys

doi:10.1051/matecconf/20179501005

Abstract

Epitaxial Al x Ga 1-x Sb layers on GaSb and GaAs substrates have been grown by atmospheric pressure metalorganic chemical vapor deposition using TMAl, TMGa and TMSb. Nomarski microscope and a profiler were employed to examine the surface morphology and growth rate of the samples. We report the effect of growth temperature and V/III flux ratio on growth rate and surface morphology. Growth temperatures in the range of 520°C and 680°C and V/III ratios from 1 to 5 have been investigated. A growth rate activation energy of 0.73 eV was found. At low growth temperatures between 520 and 540°C, the surface morphology is poor due to antimonide precipitates associated with incomplete decomposition of the TMSb. For layers grown on GaAs at 580°C and 600°C with a V/III ratio of 3 a high quality surface morphology is typical, with a mirror-like surface and good composition control. It was found that a suitable growth temperature and V/III flux ratio was beneficial for producing good AlGaSb layers. Undoped AlGaSb grown at 580°C with a V/III flux ratio of 3 at the rate of 3.5 μm/hour shows p-type conductivity with smooth surface morphology

Highlights

Because of the corresponding wavelengths of the alloys of Gallium antimonide (GaSb) based compound semiconductors cover a wide spectral range from 1.24 Pm (AlGaSb or AlGaAsSb) to 4.3 Pm (InGaAsSb), they have received increasing attention recently
There is a strong interest in growing superlattices (SLs) on GaAs substrates
GaAs substrates were prepared by degreasing in trichloroethylene (TCE), rinsing in acetone and methanol

Summary

Introduction

Because of the corresponding wavelengths of the alloys of Gallium antimonide (GaSb) based compound semiconductors cover a wide spectral range from 1.24 Pm (AlGaSb or AlGaAsSb) to 4.3 Pm (InGaAsSb), they have received increasing attention recently. They became promising candidates for applications in long wavelength lasers and photodetectors for fibre optic communication systems [1]. Growth of the SLs by metalorganic chemical vapor deposition (MOCVD) is more challenging than that by MBE [6], [7] especially for the growth on GaAs substrates due to the 7.8% lattice mismatch between GaAs and GaSb

Methods

Results

Conclusion