Pillar structures with a sub-micron space fabricated by macroporous-based micromachining

Abstract

Abstract This paper reports a new macroporous-based micromachining technique. Macroporous silicon is formed by electrochemical etching in hydrofluoric acid. This etching technique produces straight pores with a high aspect ratio. In this work, the technique is extended to create oxide pillars. The pillars are made by thermal oxidation, followed by an etch-back of the silicon. The SiO 2 pillar structures have a 200 nm space in a channel formed on a silicon substrate. The space between the SiO 2 pillars is less than the lithographic resolution. These structures can be used for DNA separation.