Abstract: A rapid switching rotating disk reactor has an elongated injector for injecting an inert gas into the chamber of a rotating disk reactor. The nozzle of the injector is proximate to the center of the rotating wafer for the purpose of providing an inert gas flow to produce an inert gas boundary layer above the wafer. Whenever the environment of the chamber is to be changed by an introduction of another fluid medium, the injector is activated to provide an inert boundary layer atop the semiconductor wafer, wherein any processing caused by the reactive gases in the chamber is prevented from occurring. Once the chamber is filled with the subsequent fluid medium, the injector is turned off in order for the next processing to commence.

Abstract: A rapid switching rotating disk reactor has an elongated injector for injecting an inert gas into the chamber of a rotating disk reactor. The nozzle of the injector is proximate to the center of the rotating wafer for the purpose of providing an inert gas flow to produce an inert gas boundary layer above the wafer. Whenever the environment of the chamber is to be changed by an introduction of another fluid medium, the injector is activated to provide an inert boundary layer atop the semiconductor wafer, wherein any processing caused by the reactive gases in the chamber is prevented from occurring. Once the chamber is filled with the subsequent fluid medium, the injector is turned off in order for the next processing to commence.

Abstract: A wafer chuck is used to support a circular silicon wafer, which was formed from a single wafer casting process, in order to perform monocrystalline silicon regrowth. The cast wafer, having a monocrystalline silicon seed, located at its center, rests atop raised portions of the chuck and is held in place by vaccum at the center and the perimeter. The rest of the underside of the wafer is physically separated from the chuck surface by pressurized gas. An annular laser beam is then used to melt the silicon from the seed outward to grow the wafer into a monocrystalline form.

Abstract: An apparatus for casting a single silicon wafer. A quartz drum having a slotted opening pours measured amounts of granulated or powdered silicon into a crucible. Heaters then melt the solid silicon to provide a molten silicon in the crucible. Utilizing controlled gas pressure, the molten silicon is poured from the crucible onto a wafer chuck in order to cast a single silicon wafer.

Abstract: A wafer chuck is used to support a circular silicon wafer, which has formed from a single wafer casting process, in order to perform monocrystalline silicon regrowth. The cast wafer, having a monocrystalline silicon seed, located at its center, rests atop raised portions of the chuck and is held in place by vacuum at the center and the perimeter. The rest of the underside of the wafer is physically separated from the chuck surface by pressurized gas. An annular laser beam is then used to melt the silicon from the seed outward to grow the wafer into a monocrystalline form.

Abstract: Method and apparatus are provided for overcladding a preform rod (22). The preform rod is aligned with and inserted into an overcladding tube (30). The outer diameter of the preform rod and the inner diameter of the tube are such that the clearance between the tube and the rod does not exceed a predetermined value. Successive increments of length of the tube and rod therein are subjected to a controlled zone of heat while the pressure inside the tube is maintained at a value which is substantially less than that outside the tube. This causes the tube to be collapsed onto the preform rod to provide an overclad preform and subsequently a drawn optical fiber in which the overcladding is substantially concentric with respect to the optical fiber core.

Abstract: Fibers are coated with a metal layer by applying onto the fiber a relatively high viscosity slurry comprising an alloy in the form of liquid and solid phases. This allows application of metal coatings on layers that do not "wet" with the liquid metal. For example, an optical fiber having a soft polymer layer to reduce microbending losses is coated with a metal to prevent moisture entry. An alloy of Bi-Sn or In-Sn, among others, allows coating at a relatively low temperature to prevent polymer degradation. Other fibers for various uses can also be advantageously coated with this technique.

Abstract: Fibers, including optical fibers, are coated under pressure to reduce the amount of bubbles entrapped in the coating. Fluid coating material is directed radially toward the fiber, typically through a porous material or radial channels in a coating applicator. The passage diameter for the fiber is large enough to prevent contacting the fiber, while the pressure of the fluid coating material is high enough to substantially prevent air from entering the applicator. Fiber coating speeds up to at least several meters/second are possible.