Abstract:
Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.
Abstract:
A method of method of forming or repairing a superalloy article having a columnar or equiaxed or directionally solidified or amorphous or single crystal microstructure includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array corresponding to a pattern of a layer of the article onto a powder bed of the superalloy to form a melt pool; and controlling a temperature gradient and a solidification velocity of the melt pool to form the columnar or single crystal microstructure.
Abstract:
Methods for purifying reaction precursors used in the synthesis of inorganic compounds and methods for synthesizing inorganic compounds from the purified precursors are provided. Also provided are methods for purifying the inorganic compounds and methods for crystallizing the inorganic compounds from a melt. γ and X-ray detectors incorporating the crystals of the inorganic compounds are also provided.
Abstract:
An additive manufacturing system utilizing an epitaxy process, and method of manufacture, utilizes a heating source and a cooling source to control thermal gradients and a solidification rate of each slice of a workpiece manufactured from a seed having a directional grain microstructure. An energy gun is utilized to melt selected regions of each successive layer of a plurality layers of a powder in a powder bed to successively form each solidified slice of the workpiece.
Abstract:
An additive manufacturing system utilizing an epitaxy process, and method of manufacture, utilizes a heating source and a cooling source to control thermal gradients and a solidification rate of each slice of a workpiece manufactured from a seed having a directional grain microstructure. An energy gun is utilized to melt selected regions of each successive layer of a plurality layers of a powder in a powder bed to successively form each solidified slice of the workpiece.
Abstract:
In a method of manufacturing a semiconductor device of a three-dimensional structure having a semiconductor substrate and another single crystal semiconductor layer formed thereon, the another single crystal semiconductor layer is prepared by melting a vapor-deposited amorphous or polycrystalline semiconductor layer by the energy of laser beams then solidifying and converting the layer into single crystals. For initiating the melting at selected regions of the layer, the layer is formed at the surface thereof with a silicon nitride film of a uniform thickness and a silicon nitride film with a thickness at the region corresponding to the selected region different from that of the remaining region. The region thicker or thinner than other region reflects the laser energy at different reflectivity thereby to provide a desired temperature distribution.
Abstract:
An improved method and apparatus for crystallizing amorphous or polycrystalline material is disclosed. In this invention, a material which is to be crystallized is formed on a substrate and single crystalline seed material is disposed in contact and/or adjacent to or with at least a portion of the material which is to be crystallized. A layer of material which serves as a "wetting agent" is then formed over the material to be crystallized. The structure thus formed is subjected to a heat treatment which melts the material being crystallized and when the material solidifies its crystalline structure is substantially epitaxial based on the seed material. The "wetting agent" layer serves to prevent deleterious balling up of the material during crystallization.
Abstract:
Temperature variations across the surface of a semiconductor wafer (12), having at least one major surface thereof exposed to a source of radiant heat energy (18), are reduced by positioning a reflective ring (30, 30', 30" or 30'") proximate the wafer edge (28). The reflective ring (30, 30', 30" or 30'") reflects the heat energy towards the wafer periphery (27) to provide substantially uniform heat across the wafer.
Abstract:
A method for eliminating laser induced substrate fissures associated with laser annealed crystallization of patterned silicon areas, for increasing the yield of useable single crystal areas. The fissures are created by enhanced etching of the substrate, at the exposed edges of the areas, during the removal of a dimension stabilizing encapsulating layer. A post crystallization, high temperature anneal, in an oxidizing atmosphere prevents the enhanced etching of the substrate.
Abstract:
Apparatus is provided for semiconductor ribbon-to-ribbon conversion in a rigid edge mode. A combination carrier and mask is provided by which the ribbon is secured during the conversion process. The carrier holds the ribbon and simultaneously masks the edges of the ribbon from the heating effects of an impinging energy beam. The energy beam, such as a laser or electron beam, impinges on the ribbon and creates a molten zone which extends through the thickness of the ribbon. During the growth process, the molten zone is caused to move along the length of the ribbon. The mask prevents melting of the extreme edge portions of the ribbon and thus allows a rapid growth rate and a stable molten zone without sophisticated electronic equipment to gate the energy beam at the ribbon edges.