Hydrogen-implantation induced silicon surface layer exfoliation

The physical mechanisms of hydrogen-induced silicon surface cleavage were i nvestigated using the combination of cross section transmission electron mi croscopy (XTEM) and Rutherford back-scattering spectrometry (RBS) channelli ng analysis. A [100]-oriented silicon wafer was implanted with 175 keV prot ons to a dose of 5 x 10(16) cm(-2). The implanted wafer was bonded to a SiO 2-capped [100]-oriented silicon wafer and then heated to an elevated temper ature of 600 degreesC to produce exfoliation. The damage region of the impl anted silicon was examined by XTEM, which revealed the presence of hydrogen -filled platelets. The depth distribution of the implantation damage was al so monitored by RES in the channelling condition in the as-implanted state as well as after the cleavage of the silicon wafer. A comparison of the RES and XTEM indicates that the nucleation of hydrogen-filled microcavities an d the cleavage of the silicon wafer take place above the hydrogen concentra tion peak near the implantation damage peak, revealing the crucial role of the implantation damage in the crystal in terms of hydrogen-induced silicon surface layer exfoliation.