Abstract: A method of manufacturing a projection optical system (37) for projecting a pattern from a reticle to a photosensitive substrate, comprising a surface-shape-measuring step wherein the shape of an optical test surface (38) of an optical element (36) which is a component in the projection optical system is measured by causing interference between light from the optical surface (38) and light from an aspheric reference surface (70) while the optical test surface (38) and said reference surface (70) are held in integral fashion in close mutual proximity. A wavefront-aberration-measuring step is included, wherein the optical element is assembled in the projection optical system and the wavefront aberration of the projection optical system is measured.

Abstract: An interferometer that uses plane mirrors at grazing incidence to create interference fringes in the extreme ultraviolet and x-ray portions of the spectrum. X-ray interferometry has historically been implemented through narrow band, diffractive systems that split the wavefront. By using two separate optical channels at grazing incidence to create interference from two areas of the wavefront, this system has broad band response and much higher efficiency. The interferometer has applications to telescopes, microscopes and spectrometers in the extreme ultraviolet and x-ray, and high contrast imaging in the visible.

Abstract: A method for inspecting masks used in x-ray lithography is described. An x-ray lithography mask is placed over a glass surface, followed by exposure of the mask and glass surface to soft x-rays. Portions of the mask absorb the soft x-rays while other portions of the mask, corresponding to circuit elements, allow the soft x-rays to strike the glass surface. The soft x-rays striking the glass surface cause the glass surface to darken, thereby forming an image of the circuit pattern in the glass surface corresponding to the stenciled circuit in the mask. An inspection of the image can reveal any defects in the x-ray lithography mask.

Abstract: A phase-contrast X-ray imaging system according to the present invention comprises an X-ray interferometer, wherein X-ray interfering beams thicker than 2 cm.times.2 cm are formed enabling observation of comparatively large objects. The X-ray interferometer is constituted by two crystal blocks which each are monolithically cut out from ingots of crystal and have two wafers which function as X-ray half mirrors. An optical equipment, a chamber, and a feedback system are incorporated to adjust and stabilize the crystal blocks. A device is also incorporated to obtain an image showing the distribution of the X-ray phase shift with which diagnosis become easier and reliable.

Abstract: A phase-contrast X-ray imaging system according to the present invention comprises an X-ray interferometer, wherein X-ray interfering beams thicker than 2 cm.times.2 cm are formed enabling observation of comparatively large objects. The X-ray interferometer is constituted by two crystal blocks which each are monolithically cut out from ingots of crystal and have two wafers which function as X-ray half mirrors. Optical equipment, a chamber, and a feedback system are incorporated to adjust and stabilize the crystal blocks. A device is also incorporated to obtain an image showing the distribution of the X-ray phase shift with which diagnosis become easier and reliable.

Abstract: Methods for forming X-ray images having 0.25 .mu.m minimum line widths on X-ray sensitive material are presented. A holgraphic image of a desired circuit pattern is projected onto a wafer or other image-receiving substrate to allow recording of the desired image in photoresist material. In one embodiment, the method uses on-axis transmission and provides a high flux X-ray source having modest monochromaticity and coherence requirements. A layer of light-sensitive photoresist material on a wafer with a selected surface is provided to receive the image(s). The hologram has variable optical thickness and variable associated optical phase angle and amplitude attenuation for transmission of the X-rays. A second embodiment uses off-axis holography. The wafer receives the holographic image by grazing incidence reflection from a hologram printed on a flat metal or other highly reflecting surface or substrate.

Abstract: X-ray wave diffraction devices are constructed using atomic layer epetaxy. A crystalline substrate is prepared with one or more surface areas on which multiple pairs of layers of material are to be deposited. These layers are then formed by atomic layer epetaxy on the surface areas of the substrate, one on top of another, with the material of each layer of each pair being selected to have a different index of refraction from that of the material of the other layer of each pair. The layers are formed so that the thickness of each layer of a pair is substantially the same as that of the corresponding layer of every other pair and so that x-ray waves impinging on the layers may be reflected therefrom. Layer pairs having a thickness of about 20 angstroms or less are formed on the substrate.

Abstract: A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment.

Abstract: The invention relates to X-ray tubes, and more particularly to cathodes for such tubes. The invention lies in the cathode, which includes an electron-emitting filament (26), being made in the form of a main body (10) of insulating material having metal electrodes (16 and 19) deposited thereon which are insulated from one another by the main body. The filament (26) and the electrodes (16 to 19) are connected to conductors (27, 21 to 23) which pass through the main body.

Abstract: Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.

Abstract: Holographic X-ray images are produced representing the molecular structure of a microscopic object, such as a living cell, by directing a beam of coherent X-rays upon the object to produce scattering of the X-rays by the object, producing interference on a recording medium between the scattered X-rays from the object and unscattered coherent X-rays and thereby producing holograms on the recording surface, and establishing the wavelength of the coherent X-rays to correspond with a molecular resonance of a constituent of such object and thereby greatly improving the contrast, sensitivity and resolution of the holograms as representations of molecular structures involving such constituent. For example, the coherent X-rays may be adjusted to the molecular resonant absorption line of nitrogen at about 401.3 eV to produce holographic images featuring molecular structures involving nitrogen.