InAsSbBi and InSbBi: Potential Material Systems for Infrared Detection
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InAsSbBi and InSbBi: POTENTIAL MATERIAL SYSTEMS FOR INFRARED DETECTION S. M. BEDAIR, T.P. HUMPHREYS, P. K. CHAING, and T. KATSUYAMA Electrical and Computer Engineering Department North Carolina State University Raleigh, North Carolina 27695-7911 ABSTRACT InSb1_x Bix (0.01 < x < 0.14) and InAsSbBi quaternary alloys are potentially attractive materials for the development of semiconductor infrared detectors covering the 8-14 *m range [1,2,3]. We report for the first time, MOCVD growth of InSoI_x Bix (0.01 < x < 0.14) and InAs1_x_y Sbx Biy with 0.5 < x < 0.7 and 0.01 < y < 0.04 on both GaAs and InSb substrates using AsH3 , TMSb TEI and TMBi. Electrical measurements of the undoped InSbo0 Bi0 .0 1 shows a background carrier concentration of approximately IO1b/cm3 and a room temperature mobility of 20,215 cm2 /V.sec. To-date, these are the best reported electrical measurements for this ternary alloy. The formation of a secondary Bi phase and single crystal growth of metallic bismuth-antimony at the surface of InSblx Bix which results in deterioration of morphology with increasing values of x is also investigated. A wide range of analytic techniques, including SEM, EDX, electron microprobe and AES have been employed in our surface analysis.
Introduction This paper reports the first results on the epitaxially growth of thin film InSb1_x Bix (0.01 < x < 0.14) and InAs1_x_y Sbx Biy with 0.5 < x < 0.7 and 0.01 < y < 0.04 semiconducting alloys by MOCVD. Present results include growth parameters, electrical, and crystal characterizations. Surface derived features for InSbix Bix were also investigated by SEM (scanning electron microscopy) with supplemental element identifications by EDX (energy dispersive X-ray analysis), electron microprobe analysis and AES (Auger electron spectroscopy).
Mat. Res. Soc. Symp. Proc. Vol. 90. - 1987 Materials Research Society
448
Results and Discussion Epitaxial layers were grown in a vertical quartz reactor operating at atmospheric pressure. Arsine (AsH 3 ), Triethylindium (TEI) (Alfa), trim thylantimony (TMSb) (Alfa) and trimethylbismuth (TMBi) (Alfa) were used as arsenic indiu4 antimony and bismuth sources, respectively. The TiviBi bubbler was maintained at approximately -12 , thus keeping the partial pressure of the TMBi vapor in the gas phase low enough to deposit a few percent of Bi in the solid phase. Epilayers were grown on both (100) InSb and Cr doped semi-insulating GaAs at a growth temperature of 445 'C. Compiled in Table I is a summary of the growth parameters, solid composition, carrier concentration and carrier mobility for several InSb._xBix and InAsSbBi samples. In the absence of a high resistivity InSb substrate all Hall measurements were conducted on InSbD_x Bix and InAsSbBi epilayers deposited on semi-insulating (100) GaAs. All grown InSb1 _Y Bix epilayers were n-type with carrier concentrations in the low 1016/cm-n to 3 the 101 7 /cm range. The sane range of carrier concentration was also observed for the deposition of epilayers of InSb under similar conditions (without Bi
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