3D micro- and nano-machining of hydrogenated amorphous silicon films on SiO₂/Si and glass substrates

Abstract

We report on the hydrogen-assisted deep reactive ion etching of hydrogenated amorphous silicon (a-Si:H) films deposited using radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD). High aspect-ratio vertical and 3D amorphous silicon features, with the desired control over the shaping of the sidewalls, in micro and nano scales, were fabricated in ordered arrays. The suitable adhesion of amorphous Si film to the underlayer allows one to apply deep micro- and nano-machining to these layers. By means of a second deposition of amorphous silicon on highly curved 3D structures and subsequent etching, the fabrication of amorphous silicon rings is feasible. In addition to photolithography, nanosphere colloidal lithography and electron beam lithography were exploited to realize ultra-small features of amorphous silicon. We have also investigated the optical properties of fabricated hexagonally patterned a-Si nanowire arrays on glass substrates and demonstrated their high potential as active layers for solar cells. This etching process presents an inexpensive method for the formation of highly featured arrays of vertical and 3D amorphous silicon rods on both glass and silicon substrates, suitable for large-area applications.

Adjustable optical response of amorphous silicon nanowires integrated with thin films

“…Top-down etching techniques based on reactive ion etching (RIE) for ordered [33] as well as disordered [30,33] arrangements of nanowires have been reported previously. We use inductively coupled plasma reactive ion etching (ICP-RIE) instead for better control of the diameter and length of the nanowires.…”

Nitrogen-doped amorphous carbon-silicon core-shell structures for high-power supercapacitor electrodes

“…This image reveals that despite the considerable thickness of a -C:N film (800 nm), the layer has followed the scallops on the walls of the initial microrods in a conformal fashion. The evolution of scallops is an inevitable result of sequential etching in DRIE processes 29 as shown in the inset of Fig. 3(a) .…”

White paper on the future of plasma science and technology in plastics and textiles

“…three‐dimensional nanopatterning is the most promising development for Plasma nanopatterning. Through a sequential passivation reactive ion etching (SPRIE) 2D CC arrangements were transcribed into well‐ordered three‐dimensional architectures . The deep reactive ion etching (DRIE) process is convenient to prepare ultra‐high aspect ratio (ASR) Si nanowires (SiNWs) .…”