Nanomachining of (110)-oriented silicon by scanning probe lithography and anisotropic wet etching

Abstract

We have demonstrated that silicon nanostructures with high aspect ratios, having ϳ400 nm structural height and ϳ55 nm lateral dimension, may be fabricated by scanning probe lithography and aqueous KOH orientation-dependent etching on the H-passivated ͑110͒ Si wafer. The high spatial resolution of fabricated features is achieved by using the atomic force microscope based nano-oxidation process in ambient. Due to the large ͑110͒/͑111͒ anisotropic ratio of etch rate and the large Si/SiO 2 etch selectivity at a relatively low etching temperature and an optimal KOH concentration, high-aspect-ratio gratings with ͑111͒-oriented structural sidewalls as well as hexagonal etch pit structures determined by the terminal etch geometry can be obtained.

A MEMS fabricated cell electrophysiology biochip for in silico calcium measurements

“…TMAH has the advantage that it has high selectivity for etching SiO 2 as compared to Si, less than 5 nm/h for the same conditions as mentioned before which enables usage of thin oxide layers as mask for etching relatively deep silicon surfaces. However, KOH has a much higher selectivity for the silicon crystal planes as compared to TMAH, approximately 600:400:1 for {1 1 0}:{1 0 0}:{1 1 1} planes [16]. Also a properly controlled KOH etch tends to produce a smoother surface finish as compared to TMAH.…”

Nano-chemistry and scanning probe nanolithographies

“…The combination of those elements allows the fabrication of a wide range of electronic and mechanical devices with nanometer-scale features. [22][23][24][25][26][27][28][29] In some cases LON is used in combination with other methods such as photolithography, electron beam lithography or chemical wet etching to fabricate the desired device. In those cases, the critical or most relevant features of the device are fabricated by local oxidation.…”

Growth and characterization of axially periodic Zn2SnO4 (ZTO) nanostructures

“…Organizing nanoscale building blocks into complex nanostructures especially periodic ones, is always a target for researchers [23][24][25][26]. Although the ''top-down'' approach for the fabricating nanostructures has made great progress in the past few years, the fabrication of complex structure in nanoscale is still a challenge [27,28]. Self-organized growth provides an effective approach for fabrication of these structures.…”