ABSTRACT
The effect of substrate and annealing in crystallization of Si/SiO2 structures was studied with a transmission electron microscope (TEM). Samples were grown both on silicon and quartz substrates and the 20 × 2 nm samples were annealed with rapid thermal annealing (RTA) and furnace annealing (FA) methods. The 20 × 5 nm sample was annealed only with RTA. The annealing time for RTA was 5 s and for FA one hour. Annealing temperature was 1200 °C for RTA and 1000 °C for the FA method. In the case of quartz and silicon substrates, the separate layers of Si and SiO2 could not be observed in a bright field image. In the case of quartz, electron diffraction studies showed more amorphous structure, whereas for silicon it showed some evidence of crystallinity. In the silicon substrate, from the 20 × 2 nm sample separate Si and S1O2 layers were seen along with small crystallites and their presence was confirmed with selected area diffraction patterns (SADP). Generally, the size of crystallites was approximately the same as the layer spacing (about 5nm) but in a few cases crystallites grew through the Si02 layer as well. With different annealing methods, no remarkable difference in layer structure was observed.
