Time-dependent exposure dose of hydrogen silsesquioxane when used as a negative electron-beam resist

Abstract

Articles you may be interested inFabrication of nanodot array molds by using an inorganic electron-beam resist and a postexposure bake Electron beam lithography patterning of sub-10 nm line using hydrogen silsesquioxane for nanoscale device applications J.Hydrogen silsesquioxane ͑HSQ͒ is used as a high-resolution, negative-tone, inorganic electron-beam resist for use in nanoimprint lithography. Previous studies show that 1 week long exposure delay in air decreases sensitivity and enhances the contrast of HSQ ͓F. C. M. J. M. van Delft, J. Vac. Sci. Technol. B 20, 2932 ͑2002͔͒. In this work, the authors report that the electron-beam dose required for high-resolution ͑sub-50-nm͒ HSQ patterning is shown to be very sensitive to the time the sample has been at room temperature. For example, a sample written with nanoscale features at constant e-beam dose will increase in size approximately 66% per hour of time at room temperature. The minimum feature size for a given dose depends on the ambient conditions the sample was stored in ͑air, nitrogen, vacuum͒. Samples stored in vacuum are not exempt from the feature broadening. Long e-beam writing times for large-area patterning of nanoscale features will likely suffer from this time dependence unless the exposure dose is varied during the e-beam writing. The experiments relating the various ambient conditions and the minimum feature size under dose control are presented.

A General Approach to Semimetallic, Ultra‐High‐Resolution, Electron‐Beam Resists

“…nanoparticles were prepared via the reduction of Pd(acac) 2 (acac ¼ acetylacetonate; 97%, CH 3 COCHCOCH 3 ) by 1,2-hexadecanediol (90%, HOCH 2 HOCH(CH 2 ) 13 CH 3 ) and thermal decomposition of M x (CO) y [such as Fe(CO) 5 , Co 2 (CO) 8 . Fluka Chemie AG, Buchs, Switzerland] in a high-temperature solution ($310 8C) of dioctylether [98%, (CH 3 (CH 2 ) 7 ) 2 O] under Ar protection in a vacuum line.…”

“…After this synthesis, the surfaces of the fine PtM nanoparticles adsorbed the surfactants, www.afm-journal.de which led to bifunctional PtM nanoparticles surface-functionalized with hydrophilic -NH 2 , -COOH and hydrophobic CH 3 (CH 2 ) 7 CH:CH(CH 2 ) 7 -groups. In addition, the PtM nanoparticles were controlled at a fine size scale of 1-3 nm by optimizing the synthesis parameters, such as in situ reaction at high temperature (310 8C) and high stirring speed (!3000 rpm) for the reaction solution, and optimized ratio of components [the molar feed ratio of Fe(CO) 5 or Co 2 (CO) 8 to Pd(acac) 2 (acac: acetylacetonate) was 4:1 and 2:1, respectively]. By this synthesis procedure, the surface-functionalized fine PtM colloidal nanoparticles were easily and stably doped into the negative and positive resists with strong molecular interaction forces through the functional groups.…”

“…[1,2,5] Thus, despite many kinds of positive and negative resists being developed and available commercially, only a few of them can achieve fine resist nanopatterns (<50 nm) through critical control of the procedures in the e-beam lithography process. [8][9][10] In addition, because of the poor ion-beam etching (IBE) resistance of resists, the resist nanopatterns can only be transferred onto some single-layer, nonferrous metal film or semiconductor substrates by using a lift-off method or chemical reactive-ion etching (RIE). [8][9][10] It is known that the lift-off method for resist-pattern transferring is not suitable for the fabrication of very fine or high-density nanosensors because of problems such as pattern sidewalls.…”

“…[8][9][10] In addition, because of the poor ion-beam etching (IBE) resistance of resists, the resist nanopatterns can only be transferred onto some single-layer, nonferrous metal film or semiconductor substrates by using a lift-off method or chemical reactive-ion etching (RIE). [8][9][10] It is known that the lift-off method for resist-pattern transferring is not suitable for the fabrication of very fine or high-density nanosensors because of problems such as pattern sidewalls. [11] As an approach to solving the issues of fine pattern transferring, some inorganic resists [e.g., LiF(AlF 3 ), Ge x Se 1-x ] are developed.…”

Comparison of EB Exposure Characteristics between HSQ and Calix Arene of High Resolution Negative Resist

“…3) In fact, we performed the following experiment to investigate EB exposure stability using both resists. Each resist films were exposed under two different kinds of condition.…”