Proximity effect correction for 20nm dimension patterning

Electron Beam Direct Writing (EBDW) has been applied to various applications such as prototyping or small amount production of electronic devices. Originally, proximity effect in EBDW is considered as the problem of the background energy difference caused by the pattern density distribution. However, the critical dimensions of target patterns are getting smaller, we cannot ignore influences of the forward scattering. Theoretically, when the critical dimension is close to 3 or 4 times of forward scattering range, influence cannot be ignored. For example, in case ofthat corresponds, fabricating 20 nm dimension patterns by Nano Imprint Lithography (NIL) which is significant candidate of next generation lithography technology. Because it requires original dimension (1:1) mold. Therefore proximity effect correction (PEC) system which considers the forward scattering must be important. We developed simulation-based proximity effect correction system combined with data format conversion, works on Linux PC cluster. And we exposed the patterns which are dose compensated by this system. Firstly, we have speculated parameters about backward scattering parameters by exposing 100 nm line and space patterns. We got following parameters, beta (backward scattering range) = 32 urn, eta (backward scattering coefficient) = 2.5. Secondary, we have exposed Line and Space patterns whose dimensions are from 20 nm to 100 nm. We found that smaller and dense patterns have trend to be over exposed and bigger. Experimental specification is following, EB Direct Writing system is JBX-9300FS (lOOkeV ace. Voltage) by JEOL co.ltd, (Japan) , resist is HSQ (FOx 12) by Dow Coming co. (United States), substrate is Si

Algoriphagus sanaruensis sp. nov., a member of the family Cyclobacteriaceae, isolated from a brackish lake in Hamamatsu, Japan

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Single-molecule imaging analysis of elementary reaction steps of <i>Trichoderma reesei</i> cellobiohydrolase I (Cel7A) hydrolyzing crystalline cellulose I_a and III_I

Trichoderma reesei cellobiohydrolase I (TrCel7A) is a molecular motor that directly hydrolyzes crystalline celluloses into water-soluble cellobioses. It has recently drawn attention as a tool that could be used to convert cellulosic materials into biofuel. However, detailed mechanisms of action, including elementary reaction steps such as binding, processive hydrolysis, and dissociation, have not been thoroughly explored because of the inherent challenges associated with monitoring reactions occurring at the solid/liquid interface. The crystalline cellulose I(α) and III(I) were previously reported as substrates with different crystalline forms and different susceptibilities to hydrolysis by TrCel7A. In this study, we observed that different susceptibilities of cellulose I(α) and III(I) are highly dependent on enzyme concentration, and at nanomolar enzyme concentration, TrCel7A shows similar rates of hydrolysis against cellulose I(α) and III(I). Using single-molecule fluorescence microscopy and high speed atomic force microscopy, we also determined kinetic constants of the elementary reaction steps for TrCel7A against cellulose I(α) and III(I). These measurements were performed at picomolar enzyme concentration in which density of TrCel7A on crystalline cellulose was very low. Under this condition, TrCel7A displayed similar binding and dissociation rate constants for cellulose I(α) and III(I) and similar fractions of productive binding on cellulose I(α) and III(I). Furthermore, once productively bound, TrCel7A processively hydrolyzes and moves along cellulose I(α) and III(I) with similar translational rates. With structural models of cellulose I(α) and III(I), we propose that different susceptibilities at high TrCel7A concentration arise from surface properties of substrate, including ratio of hydrophobic surface and number of available lanes