Zinc diffusion in n-type indium phosphide

Profiles of Zn in n‐type InP〈100〉 wafers after ampoule diffusion were measured by secondary‐ion mass spectrometry, Auger electron spectrometry, differential Hall‐effect measurements, capacitance measurements, and scanning electron microscopy. The results can be explained by an interstitial‐substitutional mechanism, in which Zn diffuses as a singly ionized interstitial and is incorporated in the In sublattice as an electrically active substitutional acceptor or as an electrically inactive complex. At Zn concentrations lower than the background donor concentration the profile is cut off, as interstitial diffusion breaks down. The acceptor solubility increases with background donor concentration. Activation energies for diffusion and solubility were found to be 1.40 and 1.0 eV, respectively.