Diffusion coefficients and activation energies for Zn diffusion into undoped and S-doped InP

We present results of open tube Zn diffusion into undoped and S-doped n-type InP over the temperature range 550–675 °C. The process yields reproducible results which are consistent with an interstitial-substitutional diffusion model. For the undoped samples, an activation energy of 1.52 eV and a diffusion constant of 4.9×10−2 cm2/s are obtained. For heavily S-doped samples, values of 2.34 eV and 1.4×103 cm2/s, respectively, result. The difference in activation energy which is comparable to the Fermi level difference in the two substrate types is consistent with the different diffusion mechanisms which occur in these two types of InP.