There has been sustained interesting in the area of band-gap III-V compound semiconductors for 3~5 μm infrared device applications.InSb is an attractive material because of its potential use for large area detector arrays

high frequency devices and magnetoresistive sonsors for position sensing.Unfortunately

InSb itself cannot be used as a substrate due to its very large parallel conduction.Semi-insulating GaAs has been widely employed as the substrate for InSb growth

because of its electrical isolation

low-cost and mechanical strength.The main obstacle to acquiring high quality InSb comes from the large lattice mismatch of 14.6%

between InSb and GaAs

which is particularly detrimental to thin films.In the experiments

obtaining high quality InSb by two-step growth process had been reported in the high mismatch systems.In this study

all the InSb epitaxial thin films were grown on SI-GaAs by VG solid source MBE.Reflection high-energy electron diffraction(RHEED) was used for

in-situ

monitoring InSb surface morphology

the effect of the buffer on quality of heteroepitaxial InSb films was systematically studied.Including a serious of samples

a GaAs buffer was not required

as it shows no apparent improvement for the quality of InSb.Optimized of the low-temperature(LT) layer was performed at maintaining binary growth

which in the cases was 350℃

and the folllowing high-temperature(HT) growth at 450℃.The epitaxial thin films characterization was presented and analyzed

including surface morphology

interface inspection and crystalline quality by atomic force microscopy(AFM)

transmission electron microscopy(TEM) and X-ray diffraction(XRD) etc.We also described the problem between the different thickness InSb epilayer and Hall-mobility.In conclusion

high quality InSb epilayers strongly depends on LT InSb buffer layer.The InSb films were grown directly onto semi-insulating GaAs substrate

for our typical InSb samples with optimized buffer layer

room temperature DCXRD FWHM of 172″ and mobility of 64300 cm

2

·V

-1

·s

-1

at 77 K

were obtained.