Abstract: Apparatus and methods are provided for converting methane in a feed stream to acetylene. A hydrocarbon stream is introduced into a supersonic reactor and pyrolyzed to convert at least a portion of the methane to acetylene. The reactor effluent stream may be treated to convert acetylene to another hydrocarbon process.

Abstract: Apparatus and methods are provided for converting methane in a feed stream to acetylene. A hydrocarbon stream is introduced into a supersonic reactor and pyrolyzed to convert at least a portion of the methane to acetylene. The reactor effluent stream may be treated to convert acetylene to another hydrocarbon process.

Abstract: A wafer holder for supporting a wafer within a CVD processing chamber includes a vertically moveable lift ring configured to support the bottom peripheral surface of the wafer, and an inner plug having a top flat surface configured to support the wafer during wafer processing. The lift ring has a central aperture configured to closely surround the inner plug. When a wafer is to be loaded onto the wafer holder, the lift ring is elevated above the inner plug. The wafer is loaded onto the lift ring in the elevated position. Then, the lift ring is maintained in the elevated position for a time period sufficient to allow the wafer temperature to rise to a level that is sufficient to significantly reduce or even substantially prevent thermal shock to the wafer when the wafer is brought into contact with the inner plug. The lift ring is then lowered into surrounding engagement with the inner plug. This is the wafer processing position of the wafer holder.

Abstract: A wafer holder comprises a circular, disc-shaped main portion and a rib extending generally downward from a lower surface of the main portion. The rib encircles the vertical center axis of the wafer holder. The upper surface of the main portion has a wafer-receiving pocket defined by an inner pocket surface surrounded by an outer shoulder. The rib is closed to completely surround a vertical center axis of the main portion. The rib helps to prevent the main portion from inducing symmetric concavity during the manufacture of the wafer holder. In other words, the rib helps to maintain the flatness of the upper surface of the outer shoulder while the main portion is made symmetrically concave.

Abstract: Susceptor designs are provided for controlling damage to wafers, particularly during cold wafer drops-off on a hot susceptor. The designs include axisymmetric grid designs, such that thermal gradients are symmetrical in the circumferential (?) direction and the same traversing any particular radial line. The grids are preferably arcuate and each have the same surface area. In one embodiment an outer zone is asymmetrically designed to induce predictable wafer curling in a saddle shape.

Abstract: An apparatus for processing a semiconductor substrate, including a process chamber having a plurality of walls and a substrate support to support the substrate within the process chamber. A radiative heat source is positioned outside the process chamber to heat the substrate through the walls when the substrate is positioned on the substrate support. In some embodiments, lenses are positioned between the heat source and the substrate to focus or diffuse radiation from the heat source and thereby selectively alter the radiation intensity incident on certain portions of the substrate. In other embodiments, diffusing surfaces are positioned between the heat source and the substrate to diffuse radiation from the heat source and thereby selectively reduce the radiation intensity incident on certain portions of the substrate.

Abstract: One or more of three different measures are taken to preheat a wafer before it is loaded into direct contact with a wafer holder, in order to provide optimal throughput while reducing the risk of thermal shock to the wafer. The first measure is to move the wafer holder to a raised position prior to inserting the wafer into the reaction chamber and holding the wafer above the wafer holder. The second measure is to provide an increased flow rate of a heat-conductive gas (such as Hs purge gas) through the chamber prior to inserting the wafer therein. The third measure is to provide a power bias to radiative heat elements (e.g., heat lamps) above the reaction chamber.

Abstract: A wafer holder for supporting a wafer within a CVD processing chamber includes a vertically moveable lift ring configured to support the bottom peripheral surface of the wafer, and an inner plug having a top flat surface configured to support the wafer during wafer processing. The lift ring has a central aperture configured to closely surround the inner plug. When a wafer is to be loaded onto the wafer holder, the lift ring is elevated above the inner plug. The wafer is loaded onto the lift ring in the elevated position. Then, the lift ring is maintained in the elevated position for a time period sufficient to allow the wafer temperature to rise to a level that is sufficient to significantly reduce or even substantially prevent thermal shock to the wafer when the wafer is brought into contact with the inner plug. The lift ring is then lowered into surrounding engagement with the inner plug. This is the wafer processing position of the wafer holder.

Abstract: An apparatus for processing a semiconductor substrate is provided. The apparatus comprises a process chamber having a plurality of walls and a substrate support to support the substrate within the process chamber. A radiative heat source is positioned outside the process chamber to heat the substrate through the walls when the substrate is positioned on the substrate support. In some embodiments, lenses are provided between the heat source and the substrate to focus or diffuse radiation from the heat source and thereby selectively alter the radiation intensity incident on certain portions of the substrate. In other embodiments, diffusing surfaces are provided between the heat source and the substrate to diffuse radiation from the heat source and thereby selectively reduce the radiation intensity incident on certain portions of the substrate.

Abstract: A wafer holder comprises a circular, disc-shaped main portion and a rib extending generally downward from a lower surface of the main portion. The rib encircles the vertical center axis of the wafer holder. The upper surface of the main portion has a wafer-receiving pocket defined by an inner pocket surface surrounded by an outer shoulder. The rib is closed to completely surround a vertical center axis of the main portion. The rib helps to prevent the main portion from inducing symmetric concavity during the manufacture of the wafer holder. In other words, the rib helps to maintain the flatness of the upper surface of the outer shoulder while the main portion is made symmetrically concave.

Abstract: One or more of three different measures are taken to preheat a wafer before it is loaded into direct contact with a wafer holder, in order to provide optimal throughput while reducing the risk of thermal shock to the wafer. The first measure is to move the wafer holder to a raised position prior to inserting the wafer into the reaction chamber and holding the wafer above the wafer holder. The second measure is to provide an increased flow rate of a heat-conductive gas (such as Hs purge gas) through the chamber prior to inserting the wafer therein. The third measure is to provide a power bias to radiative heat elements (e.g., heat lamps) above the reaction chamber.

Abstract: A wafer holder for supporting a wafer within a CVD processing chamber includes a vertically moveable lift ring configured to support the bottom peripheral surface of the wafer, and an inner plug having a top flat surface configured to support the wafer during wafer processing. The lift ring has a central aperture configured to closely surround the inner plug. When a wafer is to be loaded onto the wafer holder, the lift ring is elevated above the inner plug. The wafer is loaded onto the lift ring in the elevated position. Then, the lift ring is maintained in the elevated position for a time period sufficient to allow the wafer temperature to rise to a level that is sufficient to significantly reduce or even substantially prevent thermal shock to the wafer when the wafer is brought into contact with the inner plug. The lift ring is then lowered into surrounding engagement with the inner plug. This is the wafer processing position of the wafer holder.

Abstract: Susceptor designs are provided for controlling damage to wafers, particularly during cold wafer drops-off on a hot susceptor. The designs include axisymmetric grid designs, such that thermal gradients are symmetrical in the circumferential (&thgr;) direction and the same traversing any particular radial line. The grids are preferably arcuate and each have the same surface area. In one embodiment an outer zone is asymmetrically designed to induce predictable wafer curling in a saddle shape.