Twist-type silicon bicrystals and compliant substrates prepared from silicon-on-insulator wafers

A new approach for preparing twist-type silicon bicrystals and compliant su bstrates is reported. Thin single-crystal silicon films prepared from a sil icon-on-insulator wafer can be bonded to each other or to silicon substrate s. Thousands of silicon bicrystals bonded at different twist angles can be obtained in a single preparation process and are ready for transmission ele ctron microscopy (TEM) examination. Plan-view and high resolution cross-sec tional TEM images of the silicon bicrystals are presented. Dislocation netw ork and moire fringes of small-angle twist-type silicon boundaries are show n. This technique facilitates the systematic study of small- and large-angl e grain-boundary structures of silicon. A possible application to fabricati ng compliant substrates for heteroepitaxial growth of Si1-xGex is discussed .