Abstract: In accordance with the present invention at least two different grades of HOPG material with different d-spacings are combined to form a composite HOPG monochromator with increased spacing spread (&Dgr;d/d) defined by the combination of the two HOPG materials with each HOPG material oriented relative to one another so that their layer planes are parallel. The increased &Dgr;d/d should yield higher neutron beam intensities in certain types of backscattering instruments.
Abstract: The invention generally relates to a processing system and related methods that include a chamber, a pedestal disposed in the chamber, a shadow ring and a set of alignment and support tabs which receive and directly align a substrate with a shadow ring, substantially independently of the pedestal. In one aspect of the invention, a shadow ring is provided which includes an upper shielding portion and a lower alignment and support member. The alignment and support member preferably includes one or more alignment and support tabs. A set of lift pins are preferably disposed in the chamber that may align the substrate and shadow ring with the pedestal. At least one pedestal recess may be located in the pedestal to receive the alignment and support tabs when the pedestal is in a raised position and in some instances to align the substrate and shadow ring to the pedestal.
Abstract: The present disclosure relates to a chemical vapor deposition system including a chemical vapor deposition chamber having a wafer position at which a wafer can be placed during chemical wafer deposition processing, and a source of reactive gases for providing reactive gases to the chemical vapor deposition chamber. This system also includes a coherent radiation source for directing a beam of coherent radiation toward the wafer position, and a shield positioned between the coherent radiation source and the wafer position. This shield is adapted to distribute energy from the beam of coherent radiation across the wafer when the wafer is located at the wafer position.
Abstract: A semiconductor processing chamber, capable of withstanding low pressures while transmitting radiant energy, is provided in a lightweight, compact design. The inner surface of the window is preferably substantially flat and parallel to the wafer to be processed. The window is thin in a center portion and thicker in a surrounding peripheral portion. The thickness increases in the radially outward direction, defined between the flat inner surface and a concave outer surface. Deposition uniformity is improved by employing multiple outlet ports for distributing gas laterally in a short length, enabling a compact, symmetrical geometry. Preferably, a quadra-flow system of gas distribution is used, whereby the chamber contains one inlet port and three outlet ports distributed approximately at 90 degrees around a cylindrical side wall defining the chamber space.
Abstract: A semiconductor wafer holder which has a contact part with a held object to be held is described. The contact part is constructed of a sintered silicon carbide substrate and then coated with a dense CVD silicon carbide film which has at least one crystal plane orientation out of the (111), (110), (220) and (200) planes in Miller indices to provide excellent grindability despite high hardness to withstand abrasive wear, thus facilitating surface grinding of the contact part into an ultra smooth and flat surface without dust and pit holes. This composite material has a large modulus of elasticity, a small specific gravity, and a very low coefficient of thermal expansion, creating high strength and little change in spite of exposure heat and maintaining dimensional stability in circuit printing. The sintered material together with the crystallized CVD silicon carbide film of the .beta. structure offers an electric resistance under 10.sup.10 .OMEGA..multidot.
Abstract: A glass or metal wire is precisely etched to form the paraboloidal or ellipsoidal shape of the final desired capillary optic. This shape is created by carefully controlling the withdrawal speed of the wire from an etchant bath. In the case of a complete ellipsoidal capillary, the etching operation is performed twice in opposite directions on adjacent wire segments. The etched wire undergoes a subsequent operation to create an extremely smooth surface. This surface is coated with a layer of material which is selected to maximize the reflectivity of the radiation. This reflective surface may be a single layer for wideband reflectivity, or a multilayer coating for optimizing the reflectivity in a narrower wavelength interval. The coated wire is built up with a reinforcing layer, typically by a plating operation. The initial wire is removed by either an etching procedure or mechanical force. Prior to removing the wire, the capillary is typically bonded to a support substrate.
Abstract: A vertical processing unit 10 for semiconductor wafers has; a cylindrical processing chamber 2 having an opening 18 in an inside of an annular bottom surface, and a disk-shaped cap 6 having an annular abutting-surface 32 abutting on the annular bottom surface of the chamber. A mounting-surface 6p formed on the inside of the annular abutting-surface 32. A wafer-boat 8 for holding a wafer W to be processed is mounted on the mounting-surface 6p of the cap 6. The abutting-surface 32 has an annular groove 34A formed therein. An inert gas supply passgeway 38 is provided in communication with the annular groove 34A for supplying an inert gas into the annular groove 34A through a header 16. An ejection opening 36 for ejecting an inert gas is provided on the inner side of the annular groove 34A for communicating the annular groove 34A and the interior of the processing chamber 2. Owing to the active leaking of the nitrogen (N.sub.