Abstract: A structure for a chemical vapor deposition reactor desirably includes a reaction chamber having an interior, a spindle mounted in the reaction chamber, and a wafer carrier releasably mounted onto the spindle for rotation therewith. The spindle desirably has a shaft extending along a vertical rotational axis and a key projecting outwardly from the shaft. The wafer carrier preferably has a body defining oppositely-facing top and bottom surfaces and at least one wafer-holding feature configured so that a wafer can be held therein with a surface of the wafer exposed at the top surface of the body. The wafer carrier desirably further has a recess extending into the body from the bottom surface of the body and a keyway projecting outwardly from a periphery of the recess along a first transverse axis. The shaft preferably is engaged in the recess and the key preferably is engaged into the keyway.

Abstract: Methods for stress control in thin silicon (Si) wafer-based semiconductor materials. By a specific interrelation of process parameters (e.g., temperature, reactant supply, time), a highly uniform nucleation layer is formed on the Si substrate that mitigates and/or better controls the stress (tensile and compressive) in subsequent layers formed on the thin Si substrate.

Abstract: An acoustical transformer having a last matching section that includes a protective barrier of low permeability. The protective barrier is in contact with a test medium. In one embodiment, the protective barrier comprises one or more low permeability layers, such as a metallic foil or metallic coating(s) disposed on a low impedance layer such as polyimide, so that the low impedance layer and the protective barrier constitute the last matching section of the acoustical transformer. In other embodiments, the protective barrier comprises a fluoropolymer. A method for determining the thicknesses of the various layers of the acoustical transformer for enhanced performance is also disclosed.

Abstract: A spalling process can be employed to generate a fracture at a predetermined depth within a high quality crystalline nitride substrate, such as a bulk GaN substrate. A first crystalline conductive film layer can be separated, along the line of fracture, from the crystalline nitride substrate and subsequently bonded to a layered stack including a traditional lower-cost substrate. If the spalled surface of the first crystalline conductive film layer is exposed in the resulting structure, the structure can act as a substrate on which high quality GaN-based devices can be grown.

Abstract: A method of in-situ temperature measurement for a wafer treatment reactor such as a chemical vapor deposition reactor desirably includes the steps of heating the reactor until the reactor reaches a wafer treatment temperature and rotating a wafer support element within the reactor about a rotational axis. The method desirably further includes, while the wafer support element is rotating about the rotational axis, obtaining first operating temperature measurements using a first operating pyrometer that receives radiation from a first portion of the wafer support element, and obtaining first wafer temperature measurements using a wafer temperature measurement device that receives radiation from at least one wafer, the wafer temperature measurement device located at a first position.

Abstract: An apparatus includes a carrier rotatable about an axis of rotation where the carrier has a top surface adapted to hold at least one semiconductor wafer and a surface characterization tool which is operative to move over a plurality of positions relative to the top surface of the carrier and/or the wafer transverse to the axis of rotation. The surface characterization tool is operative to move over a plurality of positions relative to the top surface of the carrier and/or the wafer transverse to the axis of rotation and is further adapted to produce characterization signals over the plurality of positions on at least a portion of the carrier and/or on at least a portion of said major surface of the wafer as the carrier rotates.

Abstract: The surface topography of at least one wafer can be determined in-situ based on deflectometer measurements of surface tilt. The deflectometer is re-positioned by a scanning positioner to facilitate tilt mapping of the wafer surface for each of the at least one wafer. A surface height mapping engine is configured to generate a three-dimensional topographic mapping of the surface of each of the at least one wafer based on the mapping of the tilt.

Abstract: A rotating disk reactor for chemical vapor deposition includes a vacuum chamber and a ferrofluid feedthrough comprising an upper and a lower ferrofluid seal that passes a motor shaft into the vacuum chamber. A motor is coupled to the motor shaft and is positioned in an atmospheric region between the upper and the lower ferrofluid seal. A turntable is positioned in the vacuum chamber and is coupled to the motor shall so that the motor rotates the turntable at a desired rotation rate. A dielectric support is coupled to the turntable so that the turntable rotates the dielectric support when driven by the shaft. A substrate carrier is positioned on the dielectric support in the vacuum chamber for chemical vapor deposition processing. A heater is positioned proximate to the substrate carrier that controls the temperature of the substrate carrier to a desired temperature for chemical vapor deposition.

Abstract: In a rotating disk reactor (1) for growing epitaxial layers on substrate (3), gas directed toward the substrates at different radial distances from the axis of rotation of the disk has substantially the same velocity. The gas directed toward portions of the disk remote from the axis (10a) may include a higher concentration of a reactant gas (4) than the gas directed toward portions of the disk close to the axis (10d), so that portions of the substrate surfaces at different distances from the axis (14) receive substantially the same amount of reactant gas (4) per unit area. A desirable flow pattern is achieved within the reactor while permitting uniform deposition and growth of epitaxial layers on the substrate.

Abstract: A self-centering wafer carrier system for a chemical vapor deposition (CVD) reactor includes a wafer carrier comprising an edge. The wafer carrier at least partially supports a wafer for CVD processing. A rotating tube comprises an edge that supports the wafer carrier during processing. An edge geometry of the wafer carrier and an edge geometry of the rotating tube being chosen to provide a coincident alignment of a central axis of the wafer carrier and a rotation axis of the rotating tube during process at a desired process temperature.

Abstract: In a sputter deposition tool (100) of the type in which an ion source (101) generates a beam directed at a sputtering target, the sputtering target comprises an elongated exterior skirt (102) and a generally circular insert (103) positioned within the skirt, the surfaces of the skirt and insert being relatively coplanar and forming the surface of the target, with the elongated dimension of the skirt being axially oriented toward the ion source. The insert is rotated within the skirt to one of several positions during use of the target by the sputter deposition tool, to distribute wear of the target around the rotating insert and thus increase the utilization and useful life of the overall target assembly.

Abstract: A radiation thermometer utilizing an off-focus telecentric lens arrangement in chemical vapor deposition reactors. An object assembly of one or more optical components is positioned at a distance equal to its focal length from an aperture stop. The aperture stop is dimensioned so that the chief rays are substantially parallel with the optical axis of the object assembly, and so that the rays that pass through the aperture stop define a narrow solid angle about the chief rays. The off-focus telecentric arrangement thus configured is focused at infinity, but is utilized to capture radiation from a relatively proximate target (e.g., within a couple meters) that is out of focus. The capture of collimated radiation from the target diminishes the contribution of stray radiation, particularly with targets having a highly specular surface.

Abstract: A pressure-adjusting lapping element is included as a structural component of a carrier assembly in a lapping head. The lapping element includes actuator nodes that permit fine tuning of a lapping force applied through the lapping element to a work piece. An actuator assembly is directly attached to the lapping element and manipulates the individual actuator nodes. The lapping element further includes whippletree structure to permit a desired degree of flexibility in the lapping element to respond to force inputs at the actuator nodes.

Abstract: A chemical vapor deposition reactor and a method of wafer processing are provided. The reactor can include a reaction chamber having an interior and an entry port for insertion and removal of substrates, a gas inlet manifold communicating with the interior of the chamber for admitting process gasses to form a deposit on substrates held within the interior, a shutter mounted to the chamber, and one or more cleaning elements mounted within the chamber. The shutter can be movable between (i) a run position in which the cleaning elements are remote from the exhaust channel and (ii) a cleaning position in which the one or more cleaning elements engage with the shutter so that the cleaning elements remove deposited particles from the shutter upon movement of the shutter to the cleaning position.