Improved electron-beam patterning of Si with self-assembled monolayers

Abstract

A set of processes has been explored that enhances the utility of self-assembled-monolayer electron-beam resists for patterning silicon. A self-assembled monolayer resist of octadecylsiloxane was exposed using a scanning electron microscope with a 20 keV beam energy and dose of 320 μC/cm2. After the patterned monolayer was developed using ultraviolet light and ozone, it served as a wet etch mask for the underlying native oxide. Linewidths of ∼30 nm were etched in silicon using the patterned oxide as a reactive ion etch mask. The maximum etch depth achieved in silicon was 90 nm using this process.

Multiple Ink Nanolithography: Toward a Multiple-Pen Nano-Plotter

“…At present, stamping procedures do not have the resolution capabilities of scanning probe lithographic methods or electron-beam (e-beam) methods, and with respect to nlultiple inks; they pose significant aliglnnellt problems (4). Moreover, traditional high-resolution techniques (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24); such as electron and ion beam lithography and many scanlling probe methods; rely on resist layers and the backfilling of etched areas with colnponent molecules. These indirect patterning approaches can compromise the chemical purity of the structures generated and pose limitations on the types of materials and number of different materials that can be patterned.…”

Electron-beam directed materials assembly

“…33 In order to make use of the exposed areas as etch masks, an all-dry UV/ozone development step was used to remove this residual carbon material. 31,32 Because the polar surface energy plays an important role in PS-b-PMMA lamellar orientation, 16 we have investigated the effect of UV/ozone exposure on an n-butylsiloxane-modified surface. A plot of polar surface energy as a function of UV/ozone exposure time for an n-butylsiloxane-modified silicon wafer is shown in Figure 1a.…”

“…18 Previous research has shown that alkyl-and arylsiloxane self-assembled monolayers can be patterned upon exposure to 157-nm irradiation, [16][17][19][20][21] as well as other exposure techniques including 193-nm irradiation, [22][23][24][25][26][27][28] and e-beam patterning. [29][30][31][32][33] In many cases, photopatterning occurs through the cleavage of the Si-C bond. The degree of Si-C bond cleavage was proportional to the exposure dose applied.…”

Electrochemical metallization of self-assembled porphyrin monolayers

“…Many assiduous efforts, both post-assembly methods [1,2,3,4,5,6] and direct patterning methods [7,8], have been made to produce micropatterned self-assembled monolayer arrays. This investigation is an example of a post-assembly method with direct patterning -the pre-assembled porphyrin monolayer is directly and locally modified (i.e.…”