Preferred crystallographic directions of pore propagation in porous silicon layers

Results are presented that demonstrate that pores propagate along preferred crystallographic directions within both n- and p-type silicon substrates. In addition to this, pores were surprisingly found not to have a round shape. Instead, they are confined by well-defined crystallographic planes. The results from plane-view TEM technique provide quantitative information on the pore size and pore-to-pore distance distributions. These indicate that morphologies are most sensitive to the silicon substrate characteristics.<>