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Although, today, the main method for pattering almost all integrated circuits (ICs) is photolithography, charged-particle lithography – where charged particles (electrons, ions) are used for patterning – already has a wide range of applications. Electron beam lithography (EBL) is currently utilized for fabricating the photomasks essential for photolithography, as a time- and cost-effective technique for early device and technology development, and also for fabricating the imprint templates necessary for the emerging technique of nanoimprint lithography (NIL). All of these applications are enabled by single-beam writing techniques, which are undergoing continuous improvement. However, as photomask costs have increased, and continue to increase, it has become almost untenable to produce high-end ICs in low volume. Hence, today the use of field-programmable gate arrays (FPGAs) has surpassed that of the faster and more highly integrated application-specific integrated circuits (ASICs). Consequently, promising new multiple-beam writing techniques are currently under development, known as maskless lithography (ML2), for the volume production of ICs. Ion beam lithography (IBL) represents an alternative approach for the fabrication of imprint templates for NIL, with the advantage of not requiring resist processing. Currently, both EBL and IBL are the only viable methods for fabricating nano-electromechanical systems and nanotechnology devices, and therefore are essential tools for the emerging nanotechnology. Keywords: electron beam lithography; chemically amplified resist (CAR); photomask fabrication; direct-write; maskless lithography (ML2); nanoimprint template fabrication; ion beam lithography; direct-structuring

The demand for ever smaller features in integrated circuit manufacturing continues to put more stringent requirements on photomask fabrication, particularly with respect to critical dimension (CD) control. A high resolution process for making attenuated-phase-shift masks (attPSM) for the 45nm node with a negative-tone chemically amplified resist (nCAR), utilizing a new precision bake system, was evaluated. This process showed a significant performance improvement in critical dimension uniformity (CDU), respective to an established process based on an APB5500 system. A CD-uniformity improvement from 2.1nm CD 3σ to 1.3nm CD 3σ (40%) was achieved on a demanding layout. The new precision bake system utilizes an improved multi-zone hotplate design and control algorithm, which enables highly precise temperature controllability, facilitating a superior temperature ramp-up performance, as well as significantly improved temperature setpoint stability, as has been measured with a 25-point sensor mask for a 95°C bake process. The new precision bake system shall now be introduced to the market within the HamaTech MaskTrack series.

Anfange: Unter A. versteht man die Nutzung groser landwirtschaftlicher Flachen bei intensiver Bodenbearbeitung zur Gewinnung von Pflanzenertragen fur Nahrung, Kleidung und Futtermittel. Er nimmt mit der Seshaftwerdung spatmesolithischer Kulturen seinen Anfang: Alteste Pflanzenreste, die auf A. schliesen lassen, sind in Vorderasien im Gebiet des ›Fruchtbaren Halbmondes‹ aus der Zeit 8000 bis 6000 v.Chr. gefunden worden. Spater verfugten die mesopotamischen und agyptischen Hochkulturen schon uber einen entwickelten und spezialisierten A. Im griechisch-romischen Bereich schlieslich wird die Einfuhrung des A. durch die Sage in die Vorgeschichte (Geschenk der Demeter o. a. Gotter) verlegt, ist aber wohl im 4. Jahrtausend v.Chr. erfolgt. Die ersten archaologischen Befunde fur A. im griechischen Raum stammen jedoch aus der minoisch-mykenischen Epoche. In historischer Zeit ist der A. schlieslich unbestritten die wichtigste Grundlage der antiken Wirtschaft.

Several haze studies were conducted in a test environment where UV lamps and test chambers were used to simulate a wafer fab environment. This study was designed to investigate reticles experiencing different cleaning processes in a real wafer production environment. A split test was carried out to benchmark two different fabs: an 8" R & D fab and an 8" memory production fab. Reticles cleaned with UV treatment and hot DI water were exposed on ArF scanners for up to 80 hours over a period of two months. Starlight inspection before and after laser exposure confirmed no significant defect count increase after exposure. Ion chromatography (IC) results from masks cleaned on a new Steag MaskTrack cleaner suggest that hydrogenated water (H2-H2O) and ozonated water (O3-H2O) processes can further reduce the sulfate and ammonium ion residual count by 40%. UV + hot water cleaning also shows advantages in phase and transmission preservation where less than a 0.2 degree phase angle loss per clean can be achieved.

Progress towards 65 nm next-generation lithography requires unprecedented global CD uniformity, with the actual ITRS 2002 roadmap proposing 4.2 nm 3/spl sigma/ (dense lines) for 65 nm binary masks. Since resolution requirements are satisfied only by using chemically amplified resists (CARs), exposure and post-exposure bake (PEB) are key processes to successful mask making, both introducing global CD errors. Develop and etch processes potentially contribute further global CD errors. The global CD uniformity can be improved significantly by adaptive PEB, especially for CARs showing moderate to strong PEB sensitivity, like NEB22. With the 25-zone hotplate of the APB5500 bake system, facilitated through a novel calibration mask with 25 equidistant temperature sensors within the resist plane, an appropriate temperature profile can be applied during PEB. This temperature profile is automatically calculated by an adaptive optimization algorithm, based on 2-dimensional spline fitting of a CD measurement. A CD-uniformity improvement (dense lines) from 4.8 nm 3/spl sigma/ to 3.9 nm 3/spl sigma/ (/spl cong/20%) on a state-of-the-art production mask is achieved for the chrome layer (ASI, after strip inspection).

Negative-tone chemically amplified resists (nCARs), like NEB22 are promising candidates for next-generation lithography, e.g. 90 nm and 65 nm technology node and next-generation lithography. For these resists, e-beam exposure and post-exposure bake (PEB) are most critical processes, since these resists show a strong sensitivity to post-exposure delay (PED) in vacuum during e-beam writing of about 0.5 nm/h, and in air while waiting for PEB. Further, such resists show a strong PEB temperature sensitivity of up to 8 nm/K. The multi-zone hotplate approach of the APB AFB 5500 bake system with its use prior temperature uniformity results in excellent global CD-uniformity already. However, all kinds of systematic large area effects of processes, e.g. blank coat/bake, exposure, PED, the PEB itself, etch loading, etc. may transfer in additional systematic CD-errors. Such systematic, repeatable errors can be reduced during PEB by superimposing an appropriate non-uniform temperature profile onto the regular, optimized uniform bake temperature profile, thereby compensating for such CD-non-uniformities. The required temperature profile can automatically be calculated from a suitable gobal CD measurement, determined in a typical process flow. The compensation of CD-errors resulting from vacuum PED and hotplate temperature characteristics is demonstrated here, by using automated temperature profile calculation. The global CD uniformity was improved significantly, the achieved results show a typical reduction of about 20-30%, from a total global range of about 9nm to about 6-7nm on leading-edge production photomasks.

Negative-tone chemically amplified resists MES-EN1G (JSR), FEN-270 (Fujifilm ARCH), EN-024M (TOK) and NEB-22 (Sumitomo) were evaluated for binary mask making. The investigations were performed on an advanced tool set comprising a 50kV e-beam writer Leica SB350, a Steag Hamatech hot/cool plate module APB5000, a Steag Hamatech developer ASP5000, an UNAXIS MASK ETCHER III and a SEM LEO1560 with integrated CD measurement option. We investigated and compared the evaluated resists in terms of resolution, e-beam sensitivity, resist profile, post exposure bake sensitivity, CD-uniformity, line edge roughness, pattern fidelity and etch resistance. Furthermore, the influence of post coating delay and post exposure delay in vacuum and air was determined.

Amorphous metal alloys are ideally suited for interconnects in micro-electromechanical sys- tems (MEMS) because of their resistance against stress- and electromigration, and their stability in chemically aggressive environments, which should both lead to a substantial improvement of lifetime and reliability of robust sensors. While amorphous refractory metal alloys and amor- phous silicides are excellent interconnect materials for devices operating at elevated tempera- tures, these systems lack the cost-effective and easy interconnect processing of the prevalent polycrystalline aluminum alloy metallizations. Amorphous aluminum alloys are applicable to devices operating at up to 200°C, and their stressmigration resistance and chemical stability is far superior to conventional polycrystalline aluminum alloys. These new metallizations are very promising for processing interconnects, in particular because of their high strength and ductility, though having low density, and their relatively low electrical resistivity compared to other amor- phous metal alloys. Therefore these metallizations are especially suited for surface acoustic wave (SAW) sensors, where the interconnects are exposed to considerable mechanical strains. In this work amorphous Aluminum Yttrium alloy thin film metallizations deposited on appropriate sub- strates at room temperature (R.T.) by ultra-high vacuum (UHV) electron beam evaporation will be presented, and their mechanical and electronic properties together with their temperature sta- bility will be investigated.

The multizone hotplate approach of the APB5500 bake system achieves temperature uniformity significantly superior to conventional bake tools, resulting in unmatched global critical dimension (CD) uniformity from the postexposure bake (PEB) process. Progress toward 65-nm next-generation lithography, however, requires the application of negative-tone chemically amplified resists (nCARs) like NEB22. This nCAR is characterized to show a strong sensitivity to postexposure delay (PED) in vacuum during electron-beam writing of 0.5 nm/h, and also a strong PEB sensitivity of 7.8 nm/°C, both resulting in systematic CD errors. These CD errors are compensated with the APB5500 bake system during PEB by automatically applying an appropriate nonuniform temperature profile. This temperature profile is calculated by an algorithm considering the resist and mask heat transfer properties. A CD uniformity improvement from 8.9 to 6.7 nm total range (25%) on a state of the art production mask is achieved.

Summary A selected series of 33 monosubstituted nitrobenzenes, which were from commercial sources or synthesized by known methods, was tested for algicidic activity against autotrophic Chlorella vulgaris suspensions. Isoactive inhibitory values pc501) were determined from dosageeffectivness relations and used as activity parameters for structure-activity correlations. Simple and multiple regression equations are reported, discussed and compared with analogous QSAR of earlier tested series. Two separate functions have been found for meta-, para-, and ortho-derivatives.

Ideology may be discussed as an abstraction or seen in terms of its concrete manifestations. The academic field of speech communication in East Germany is described here, first, to contrast it with American practices, and second, to show how a Marxist state structures and defines speech communication.

For the important task of function selection when using technical systems, e.g. measurement and programming devices or consumer products, a talking keyboard is proposed which offers user guidance adapted to man's skills. This keyboard is equipped with a voice output module and special keys fitted with two sequentially activated switching contacts. By means of the first contact the user is enabled to select vocal user guidance information whereas by the second contact the selection of a particular function is achieved. By closing the first contact repeatedly, spoken hints with more and more details are available. The user can, however, suppress or interrupt these instructions by switching over to the second contact. In this way the talking keyboard may be used adaptively by untrained and trained users as well. Furthermore, it is suited for blind operation under severe visual load conditions, or in the dark, and it serves to the visually handicapped. For a prototype of the talking keyboard, a moderately priced voice output module with a vocabulary of 150 words was selected. For test purposes, selection is effected via a process computer. For practical use, selection is realized by a microprocessor. Pilot experiments with untrained users of a simulated machine tool show, that the time spent in consulting the operating manual during the task is clearly reduced.