Liquid phase epitaxial growth and characterization of In(Sb,Bi)

The growth of In(Bi,Sb) epilayers using liquid phase epitaxy (LPE) has been discussed. The layers were grown on a (III)B side of InSb substrate using Bi-rich solution in horizontal slider type boat. The growth conditions for high-quality planar epitaxial layers were determined. Mirrorlike surface morphology was observed using a Normarski differential interference contrast microscope. Hall and resistivity measurements performed at 300K and 77K showed an impurity contamination of the epitaxial layers. A capacitance-voltage technique has been established to determine the distribution of doping levels on the surface of InBiSb epilayers. The results indicate that the epitaxial layers of In(Sb,Bi) are n-type at room temperature, however, the time of baking solutions (before crystallisation) determined type of conductivity and the concentration of free carriers in epilayers, at 77K. For short-time-baked solution (from 5 to 20 hours), samples were p-type (carrier concentration approximately 3.10(15) cm(-3)) when for long- time-baked solutions (40-100 hours), samples were n-type (carrier concentration approximately 5.10(15) cm(-3)). We have observed that type of conductivity depends on surface morphology of the epilayers. The type of doping and the segregation coefficient k for tin for different solutions were established. For In rich solutions tin was an acceptor with k=0.0012 and for Bi-rich ones tin was a donor with k=0.0039 at 400 degrees C.