The observation of c-Si ELO on both Si(111) and Si(100) wafer orientations by TED despite Al island formation and film separation provides evidence of adequate seed formation along the oxide wall base (e.g. Fig. 3.9c). The total concentration of Si diffusors in the Al mediator film over seed regions is nearly zero since the SMME growth front provides a constant sink for Si atoms. As diffused Si atoms are incorporated into the buried Si/Al interface, they no longer contribute to the net Si diffusor concentration in the Al mediator film.

Si diffusors over oxide regions are confronted with an aluminum oxide interface (Figs. 3.8 and 3.7). The Si diffusors are reflected by this interface back into the Al mediator bulk. This heightens the total Si diffusor concentration in the Al mediator over oxide regions. After a short period of time, the Si diffusor concentration difference between the seed and oxide regions becomes very large. This concentration gradient promotes the lateral diffusion of Si into the seed region (Fig. 3.9b). However, in the case of SMM-SOI on Si(100), there is no Al mediator film near the oxide edge over the oxide region to mediate the Si diffusors. In the case of narrow oxide patterns, such as the 2/2 $\mu$m region, however, the Al islands may have been large enough over oxide to mediate lateral Si diffusion.