[en] X-ray lithography is a shadow printing technique which uses X-rays to transfer a pattern from a mask into a resist-coated wafer. Synchrotron radiation from a storage ring has advantages over the radiation from conventional X-ray sources for this purpose, since it is 2 to 4 orders of magnitude more intense and its natural collimation virtually eliminates penumbra and run-out errors. To take advantage of synchrotron radiation, we have built a beamline for X-ray lithography at the VUV storage ring of the NSLS. This beamline was designed to meet two major requirements: vacuum isolation from the UHV in the storage ring and uniform illumination over the exposure area, to achieve good linewidth control in the resist pattern. To achieve uniform illumination in the vertical direction, we use a scanning grazing-incidence mirror that sweeps the beam over the exposure area. This mirror also collimates horizontally to maximize the exposure flux. In this paper we will describe the basic design including optics, beryllium window and the calculated spectral power distribution. The performance of the beamline will be discussed in terms of experimentally achieved uniformity of illumination, mask contrast and mask substrate transmission, exposure flux and exposure times and resolution. With PMMA resist, features down to 0.25 μm have been copied with an aspect of 16 to 1 using a 40 μm mask to wafer separation. The ultimate resolution is limited by diffraction. We have begun to study a variety of resists to evaluate their suitability for X-ray lithography. (orig.)

[en] We describe a high pressure hydrogen gas time projection chamber (TPC) which is presently operating at Fermilab both as target and as recoil detector in an experiment investigating the diffraction dissociation of photons on hydrogen, γp → Xp. The TPC, which consists of two cylindrical drift regions each 45 cm in diameter and 75 cm long, measures the polar angle and the energy loss dE/dx of the recoil protons. Typically, at 15 atm of H₂ with 2 kV/cm drift field and 7 kV on the 35 μ sense wires, the drift velocity is about 0.5 cm/μ sec and the spatial resolution +- 200 μ

[en] We report on the performance of a high-pressure hydrogen-filled time-projection chamber (TPC) designed to study photon-diffraction dissociation on hydrogen. The TPC consists of two identical 75-cm-long by 45-cm-diameter drift regions filled with H² at 15 atm. It is used as an active target to measure the polar angles and dE/dx of recoil protons

[en] We have been using a high pressure hydrogen filled timed projection chamber (TPC) in a Fermilab experiment (E-612) which is investigating the diffraction dissociation of photons on hydrogen, ßp → Xp. In this paper we present details on construction and performance of the chamber and describe briefly the experiment for which it was designed. The chamber acts both as target and as track detector of recoil protons. It is used to measure the polar angle, theta, and dE/dx of protons with 10 < T < 50 MeV and 45₀ < theta < 90₀. The energy of protons is determined by stopping them in plastic scintillation counters located inside the high pressure vessel. The experiment is operating in Fermilab's tagging photon beam (20 less than or equal to p_ß less than or equal to 170 GeV/c) which provides a flux of 1 to 2 x 10₆ tagged photons per pulse with a momentum resolution of +-2%

[en] A beam line for x-ray lithography using synchrotron radiation (SR) has been built at the VUV storage ring of the National Synchrotron Light Source and is now in operation. The high intensity and good collimation of SR overcome the problems of low throughput and resolution-limiting penumbra associated with using conventional x-ray sources. The design of a beam line for SR has to deal with two problems. First, the beam line must meet the ultrahigh vacuum standards of the storage ring, and second, the emitted radiation is horizontally uniform but very nonuniform vertically. The beam line optics consist of an oscillating cylindrical mirror that scans the reflected light vertically over the exposure area and collimates the incident radiation horizontally, thus increasing the intensity by a factor of 3. We will describe the vacuum system, the beryllium window that separates the exposure chamber from the beam line, and the vacuum protection of the ring. We will show the measured uniformity of illumination. The energy density incident onto the resist as well as the energy absorbed in the resist have been determined and will be compared with the calculated power distribution. First exposures show that features down to 0.25 μm can be copied into PMMA with an aspect ratio of 10 to 1 using a 40 μm mask-to-wafer separation

[en] Results from a measurement of the inclusive diffraction dissociation of photons on hydrogen, Υp → Xp, in the range 75 < p/sub Υ/ < 148 GeV/c, 0.02 < vertical bar t vertical bar < 0.1 (GeV/c)/sup 2/ and M/sub x//sup 2//s < 0.1 will be presented. The differential cross section is dominated by a rho peak and a high mass continuum. The rho peak is exponential in t and has a slope parameter approximately equal to that of π/sup -/p → π/sup -/p. The high mass data are also exponential in t and exhibit a 1/M/sub x//sup 2/ behavior indicating strong presence of a triple-Pomeron amplitude. Scaled to the corresponding total cross sections, photon and pion dissociation look very similar as expected by factorization. The finite mass sum rule fails in a straightforward application, but is approximately satisfied if the ''incident hadron'' is considered to be the rho- meson. These results confirm the validity of the simple Vector Meson Dominance Model

[en] The chemical changes in poly(methylmethacrylate) (PMMA) caused by irradiation with deep ultraviolet (UV), x-ray, electron, and proton beams were studied by gel permeation chromatography, Fourier-transform infrared, and UV spectroscopy. The quantitative analysis of spectroscopic changes (Beer's law) demonstrated a 1:1 correspondence between the disappearance of ester groups and the generation of double bonds in the polymer chain by all types of radiation. The ratio of main chain scission to changes in the number of ester groups and unsaturated bonds was compared to determine the characteristics of degradation of PMMA by the different types of radiation. This ratio for deep UV data was very close to the quantum yield of main chain scission of PMMA as reported in the literature. High-energy radiation was /similar to/0 x more efficient than deep UV in causing main chain scission with removal of fewer ester groups. Protons induced more main chain scission than electrons. X-ray irradiation was the most efficient at causing main chain scission of the four different types of radiation

[en] We report results from a measurement of the inclusive diffractiondissociation of photons on hydrogen, γp→Xp, in the range 75< p/sub γ/<148 GeV/c, 0.02< Vertical BartVertical Bar<0.1 (GeV/c)², and M/sub X/ ²/s<0.1. Our data show an exponential t dependence and a dominant 1/M/sub X/ ² behavior for M/sub X/ ²>4 GeV². We test the finite-mass sum rule and, by comparing γp with π^-p data obtained in the same apparatus, we test factorization

[en] We describe a high pressure hydrogen gas time projection chamber (TPC) which is presently operating at Fermilab both as target and as recoil detector in an experiment investigating the diffraction dissociation of photons on hydrogen, γ p → Xp. The TPC, which consists of two cylindrical drift regions each 45 cm in diameter and 75 cm long, measures the polar angle and the energy loss d E/dchi of the recoil protons. Typically, at 15 atm of H₂ with 2 kV/cm drift field and 7 kV on the 35 μm sense wires, the drift velocity is about 0.5 cm/μs and the spatial resolution +- 200 μm. (orig.)

[en] A recently proposed method of calculating experimental lower bounds, bsub(L), on the root-mean-squared impact parameter of multiparticle processes has been applied to a variety of reactions in π^-p interactions at 15 and 147 GeV/c. The values obtained for bsub(L) show a decrease of the root-mean-square impact parameter with increasing multiplicity at fixed energy and a very slow increase, if any, of bsub(L) with energy at fixed multiplicity. Furthermore, the results might indicate the absorption effects in multiparticle production in π^-p interactions are not important. The transverse momentum transfer correlation matrices calculated in this paper have a diagonal form in agreement with multiperipheral type models. (Auth.)