Fabrication of silicon nanostructures with a scanning tunneling microscope

Abstract

A technique is presented for fabricating Si nanostructures with a scanning tunneling microscope operated in air. The process involves the direct chemical modification of a H-passivated Si(100) surface and a subsequent liquid etch. The chemically modified portions of the surface can withstand a deep (≳100 nm) liquid etch of the unmodified regions with no etch degradation of the modified surface. At a write speed of 1–10 μm/s, large-area (50 μm×50 μm) patterns with lateral feature sizes ∼25 nm are reliably fabricated.

Dissociation of a Surface Bond by Direct Optical Excitation: H-Si(100)

“…The creation of reactive surface sites by direct photodesorption may be used for further selective growth or reaction. This scheme has been demonstrated in previous STM writing experiments [31,32]. While patterning by laser induced local heating [33] or hot carrier mediated excitations is limited by the scale of thermal or carrier diffusion, the direct photodesorption mechanism can provide much better selectivity and spatial resolution.…”

Metal point contacts and metal-oxide tunnel barriers fabricated with an AFM

“…These oxide patterns have been used for a variety of purposes that include etch masks [3], templates for metalization [4] and insulating layers used to pattern thin metal films [5]. With the aid of in situ electrical measurements this last process can be used to fabricate sub-10 nm metal/oxide devices with precisely controlled electrical properties [6].…”

Field induced oxidation of silicon by SPM: study of the mechanism at negative sample voltage by STM, ESTM and AFM

“…Sugimura's group produced local oxidation at both polarities [5], observing that the oxidation rate was higher at positive sample bias (anodization). In addition, breakthroughs towards the practical application of the technique were introduced in 1993 by Day and Allee [6], who used AFM with a metallized tip instead of STM to oxidize silicon surfaces locally, and by Snow et al [7], who locally oxidized H-passivated silicon surfaces using AFM. Other relevant results that should be mentioned are those of Fay et al [8], who demonstrated that the STM-oxidized regions appear as depressed areas when imaged with STM but as raised areas when imaged with AFM, and the dependence of the oxidation on the air humidity as * Corresponding author found by several authors [9].…”