Fabrication of highly ordered nanoporous Si with high aspect ratio through prepatterning of Si using porous alumina mask

Abstract

Highly ordered nanoporous Si was prepared through the prepatterning of Si using an anodic porous alumina mask. A highly ordered array of shallow nanoconcaves was formed on Si(100) by dry etching through the nanopores of the anodic porous alumina. During electrochemical etching of the prepatterned Si, nanopores were generated at the shallow concaves. Consequently, highly ordered arrays of deep nanopores with intervals of 200 and 100 nm were obtained. This result demonstrated that the shallow concave features on Si act as initiation sites for the development of nanopores. This process is useful for the preparation of highly ordered porous Si of nanometer scale.

InAlGaAs/InAlAs MQWs on Si Substrate

“…One drawback of using the trench pattern growth is the lack of capability to trap (111)-orientated stacking faults along the parallel direction of the trenches, which can be resolved by high aspect ratio nano-porous pattern, introduced by Ref. [19]. Besides, by adopting V-grooved Si substrates [20], defect generation can be further reduced because Si (111) is easier for III-V to nucleate compared to Si (001) and antiphasedomains can be avoided for III-V epitaxy on Si {111} planes.…”