Abstract: A vapor phase epitaxy system includes a platen that supports substrates for vapor phase epitaxy and a gas injector. The gas injector injects a first precursor gas into a first region and injects a second precursor gas into a second region. At least one electrode is positioned in the first region so that first precursor gas molecules flow proximate to the electrode. The at least one electrode is positioned to be substantially isolated from a flow of the second precursor gas. A power supply is electrically connected to the at least one electrode. The power supply generates a current that heats the at least one electrode so as to thermally activate at least some of the first precursor gas molecules flowing proximate to the at least one electrode.

Abstract: Methods of depositing compound semiconductors onto substrates are disclosed, including directing gaseous reactants into a reaction chamber containing the substrates, selectively supplying energy to one of the gaseous reactants in order to impart sufficient energy to activate that reactant but insufficient to decompose the reactant, and then decomposing the reactant at the surface of the substrate in order to react with the other reactants. The preferred energy source is microwave or infrared radiation, and reactors for carrying out these methods are also disclosed.

Abstract: In chemical vapor deposition apparatus, a water carrier (32) has a top surface (34) holding the wafers and a bottom surface (36) heated by radiant heat transfer from a heating element (28). The bottom surface (36) of the wafer carrier is non-planar due to features such as depressions (54) so that the wafer carrier has different thickness at different locations. The thicker portions of the wafer carrier have higher thermal resistance. Differences in thermal resistance at different locations counteract undesired non-uniformities in heat transfer to the wafer. The wafer carrier may have pockets with projections (553, 853) for engaging spaced-apart locations on the edges of the wafer.

Abstract: An apparatus for performing non-contact material characterization includes a wafer carrier adapted to hold a plurality of substrates and a material characterization device, such as a device for performing photoluminescence spectroscopy. The apparatus is adapted to perform non-contact material characterization on at least a portion of the wafer carrier, including the substrates disposed thereon.

Abstract: A system and method for uniform deposition of material layers on wafers in a rotating disk chemical vapor deposition reaction system is provided, wherein one or more substrates are rotated on a carrier about an axis while maintaining surfaces of the one or more substrates substantially perpendicular to the axis of rotation and facing in an upstream direction along the axis of rotation. During rotating a first gas is discharged in the downstream direction towards the one or more substrates from a first set of gas inlets. A second gas is discharged in the downstream direction towards the one or more substrates from at least one movable gas injector, and the at least one movable gas inlet is moved with a component of motion in a radial direction towards or away from the axis of rotation.

Abstract: An MOCVD reactor such as a rotating disc reactor (10) is equipped with a gas injector head having diffusers (129) disposed between adjacent gas inlets. The diffusers taper in the downstream direction. The injector head desirably has inlets (117) for a first gas such as a metal alkyl disposed in radial rows which terminate radially inward from the reactor wall to minimize deposition of the reactants on the reactor wall. The injector head desirably also has inlets (125) for a second gas such as ammonia arranged in a field between the rows of first gas inlets, and additionally has a center inlet (135) for the second gas coaxial with the axis of rotation.

Abstract: A system and method for evenly heating a substrate placed in a wafer carrier used in wafer treatment systems such as chemical vapor deposition reactors, wherein a first pattern of wafer compartments is provided on the top of the wafer carrier, such as one or more rings of wafer carriers, and a second pattern of inlaid material dissimilar to the wafer carrier material is inlaid on the bottom of the wafer carrier, and the second pattern of inlaid material is substantially the opposite of the first pattern of wafer compartments, such that there are at least as many material interfaces in intermediate regions without wafer compartments as there are in wafer carrying regions with wafers and wafer compartments.

Abstract: In a rotating disk reactor for growing epitaxial layers on substrate or other CVD reactor system, gas directed toward the substrates at gas inlets at different radial distances from the axis of rotation of the disk has both substantially the same gas flow rate/velocity and substantially the same gas density at each inlet. The gas directed toward portions of the disk remote from the axis may include a higher concentration of a reactant gas than the gas directed toward portions of the disk close to the axis, so that portions of the substrate surfaces at different distances from the axis receive substantially the same amount of reactant gas per unit area, and a combination of carrier gases with different relative molecular weights at different radial distances from the axis of rotation are employed to substantially make equal the gas density in each region of the reactor.

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 gas distribution injector for chemical vapor deposition reactors has precursor gas inlets disposed at spaced-apart locations on an inner surface facing downstream toward a substrate carrier, and has carrier openings disposed between the precursor gas inlets. One or more precursor gases are introduced through the precursor gas inlets, and a carrier gas substantially nonreactive with the precursor gases is introduced through the carrier gas openings. The carrier gas minimizes deposit formation on the injector. The carrier gas openings may be provided by a porous plate defining the surface or via carrier inlets interspersed between precursor inlets. The gas inlets may removable or coaxial.

Abstract: A wafer carrier/susceptor combination for use in an epitaxial deposition process has a configuration which provides greater thermal conductivity between the susceptor and the wafer carrier in regions substantially underlying the wafers than in regions not underlying the wafers. This difference in thermal conductivity is produced by configuring the wafer carrier or susceptor so that the lower surface of the wafer carrier is disposed closer to the susceptor in regions substantially underlying the wafers than in at least some regions not underlying the wafers. By controlling the thermal conductivity so that it is greater in certain regions than in other regions, the temperature difference between the wafers and the surface of the wafer carrier can be reduced, and a more uniform temperature distribution across the surface of the wafer can be achieved. As a result, the combination may be used to deposit a more uniform coating across the entire surface of each wafer.

Abstract: A semiconductor laser diode provides high optical power output in a single diffraction-limited farfield lobe using a conventional Fabry-Perot resonant cavity and a planar well graded index separate confinement heterostructure (QW-GRINSCH) active region. An antiguide region is optically coupled to the active region of the laser. In one embodiment, the antiguide region has a lateral variation in the effective index of refraction that forms a diverging medium that causes higher order optical modes to have higher losses in the resonant cavity. The waveguide medium preferably varies in thickness and the thickness approximates a parabolic function in the lateral direction. The antiguide region is enclosed by GaAs layers to minimize oxidation at material interfaces during device fabrication.

Abstract: An improved gas distribution scheme for a multi-wafer radially injected convergent horizontal epitaxial reactor which includes two outer distribution rings, an outer injection ring, an annular susceptor, and a central exhaust tube. The converging path of the gas stream from the outer injection ring into the central exhaust tube compensates for depletion of the reactant gases along the substrate. The injector ring has a large number of evenly spaced diffuser orifices that allow the gas to expand into the growth chamber in a laminar flow pattern. The design is compact, includes the possibility of water cooling of the quartz during deposition, and allows for a resistive bakeout furnace which can be used to etch and clean the reaction chamber between runs.