Effect of Kinetics on the Morphology of Hydrogen Exfoliated Layers

Abstract

The effect of different heat treatments during the exfoliation of a thin InP layer onto a GaAs substrate is investigated. Hydrogen implantation was carried out by implanting the InP with 5 x 1016 H2+/cm2 at 150 keV. Exfoliation occurred at either 150 {degree sign}C or 300 {degree sign}C. The extended annealing at lower temperature produced smoother surfaces, 2.8 nm, compared to the sample exfoliated at 300 {degree sign}C, 8.5 nm. This change in surface morphology exhibits a much larger impact than the effect of implantation energy (i.e. straggle) on the surface morphology. The difference is attributed to the ability to trap hydrogen and form extended defects parallel to the surface at the lower temperature. Additionally, the exfoliation depth of the lower temperature specimen is slightly deeper than the specimen exfoliated at 300 {degree sign}C, indicating that the hydrogen diffuses towards the peak damage region at the higher temperatures.