Abstract: This invention discloses an ingot cutting apparatus, wherein a crystalline ingot is positioned within an etching gas and a component of the etching gas is excited by illumination of light from a light source onto the crystalline ingot, thereby making a component of the etching gas react chemically with the component of the crystalline ingot and volatilizing the component of the crystalline ingot to cut the crystalline ingot and obtain wafers and wherein light from a light source is guided to the crystalline ingot via a sheet-like, bar-like, or fiber-like optical wave guide.

Abstract: This invention discloses an ingot cutting apparatus, wherein a crystalline ingot is positioned within an etching gas and a component of the etching gas is excited by illumination of light from a light source onto the crystalline ingot, thereby making a component of the etching gas react chemically with the component of the crystalline ingot and volatilizing the component of the crystalline ingot to cut the crystalline ingot and obtain wafers and wherein light from a light source is guided to the crystalline ingot via a sheet-like, bar-like, or fiber-like optical wave guide.

Abstract: This invention discloses an ingot cutting apparatus, wherein a crystalline ingot is positioned within an etching gas and a component of the etching gas is excited by illumination of light from a light source onto the crystalline ingot, thereby making a component of the etching gas react chemically with the component of the crystalline ingot and volatilizing the component of the crystalline ingot to cut the crystalline ingot and obtain wafers and wherein light from a light source is guided to the crystalline ingot via a sheet-like, bar-like, or fiber-like optical wave guide.

Abstract: A mark detecting device usable in an alignment and exposure apparatus for aligning an alignment mark of a mask with an alignment mark of a wafer and for exposing a resist layer provided on the surface of the wafer to a pattern of the mask with radiation.

Abstract: A projection apparatus for projecting through an optical system a circuit pattern formed on a mask or reticle onto a wafer. Ambient or environment conditions of the apparatus, such as an atmospheric pressure, temperature and humidity are detected and, on the basis of the results of detection, any focus error and magnification error upon pattern projection on the wafer are corrected.

Abstract: An illumination device includes a light source; a secondary light source forming system for forming predetermined secondary light sources by use of light from the light source, the secondary light source forming system including a plurality of lens array units disposed in the direction of an optical axis and each having a plurality of lens elements distributed in a plane perpendicular to the optical axis; an optical system for directing light from the secondary light sources to a surface to be illuminated; and an actuating device for displacing at least one lens array unit in the direction of the optical axis to adjust the illuminance distribution on the surface being illuminated, while maintaining a substantially constant range of illumination on the surface being illuminated.

Abstract: A nozzle for melt spinning of pitch to produce pitch fibers which are to be used in production of carbon fibers, includes a pitch flow section and a plurality of nozzle holes provided in the bottom of the nozzle. The pitch is passed through a pitch flow turning section, a pitch reservoir section, and the plurality of nozzle holes. Pitch can be spun without causing cracks and unevenness in spinning to produce pitch fibers which can provide excellent carbon fibers on calcination.

Abstract: A semiconductor device manufacturing projection exposure apparatus in which a pattern of a reticle is projected onto a semiconductor wafer through a projection optical system having a lens element and in which the reticle is irradiated with a light of a predetermined wavelength to thereby transfer the pattern of the reticle onto the semiconductor wafer.

Abstract: An illumination apparatus for illuminating a surface, having formed thereon a pattern, to transfer the pattern onto a semiconductor wafer. The apparatus includes an elliptic mirror for forming an image of a light source, an imaging system for re-imaging the image of the light source, formed by the elliptical mirror, while causing a curvature of field, a multi-beam generating system disposed relative to the imaging system so that the optimum focus located at the off-axis position of the imaging system is coincident with an input surface of the multi-beam generating system, and a collimator for directing to the pattern surface a number of discrete light beams generated by the multi-beam generating system to illuminate the pattern surface. Whereby a uniform intensity distribution of the light illuminating the pattern surface and a high light-collecting efficiency are assured.

Abstract: The invention provides a novel pitch material useful as a base material of carbon fibers having excellent mechanical properties and characterized by a unique combination of several property parameters including the content of the optically anisotropic phase of at least 80%, a content of the pyridine-insoluble matter in the range from 30 to 70% by weight, a number average molecular weight in the range from 1000 to 1400 and a softening point in the range from 330.degree. to 380.degree. C. Such a pitch material is obtained from a starting pitch of a petroleum-based residual oil freed from light oily matter through a two-step heat treatment, of which the first step is performed at 400.degree. to 460.degree. C. under a pressure of 5 to 50 mmHg and the second step is performed at 450.degree. to 550.degree. C. for 0.2 to 30 minutes under a pressure of 0.1 to 5 mmHg. The advantages obtained by use of a film evaporator in the above mentioned heat treatment are described.