Investigation of helium implantation induced blistering in InP

Four-inch InP wafers were implanted with 100 keV helium ions with a dose of 5×1016 cm−2 and subsequently annealed in air in the temperature range of 225–400°C in order to determine the blistering kinetics of these wafers. An Arrhenius plot of the blistering time as a function of reciprocal temperature revealed two different activation energies for the formation of surface blisters in InP. The activation energy was found to be 0.30 eV in the higher temperature regime of 300–400 °C and 0.74 eV in the lower temperature regime of 225–300 °C. The implantation induced damage was analyzed by cross-sectional transmission electron microscopy, which revealed a band of defects extending from 400–700 nm from the surface of InP. The damage band was found to be decorated with a large number of nanovoids having diameters between 2 and 5 nm. These nanovoids served as precursors for the formation of microcracks inside InP upon annealing, which led to the formation of surface blisters.