Diffusion of Zinc and Tin in Indium Antimonide

The diffusion of zinc and tin in single-crystal and polycrystalline InSb has been studied with the radio-tracer technique. The temperature dependence of the diffusion coefficients can be represented by: $D\left(\mathrm{Zn}\right)=1.4\mathrm{}\times {10}^{-7\mathrm{}}\exp (-\frac{0.86}{\mathrm{kT}})$ c${\mathrm{m}}^2$/sec and $D\left(\mathrm{Sn}\right)=5.5\mathrm{}\times {10}^{-8\mathrm{}}\exp (-\frac{0.75}{\mathrm{kT}})$ ${\mathrm{cm}}^2$/sec in single-crystal InSb; and $D\left(\mathrm{Zn}\right)=1.1\mathrm{}\times {10}^{-6\mathrm{}}\exp (-\frac{0.85}{\mathrm{kT}})$ ${\mathrm{cm}}^2$/sec in polycrystalline InSb, the activation energies being in electron volts. From the penetration curves, it appears that in polycrystalline InSb the zinc diffusion is a volume diffusion while the tin diffusion is mainly a grain boundary diffusion. The different behaviors of zinc and tin in InSb are discussed on the basis of one-type and two-type vacancy mechanisms.