Abstract:
A method of modifying a substrate carrier to improve process performance includes depositing material or fabricating devices on a substrate supported by a substrate carrier. A parameter of layers deposited on the substrate is then measured as a function of their corresponding positions on the substrate carrier. The measured parameter of at least some devices fabricated on the substrate or a property of the deposited layers is related to a physical characteristic of substrate carrier to obtain a plurality of physical characteristics of the substrate carrier corresponding to a plurality of positions on the substrate carrier. The physical characteristic of the substrate carrier is then modified at one or more of the plurality of corresponding positions on the substrate carrier to obtain desired parameters of the deposited layers or fabricated devices as a function of position on the substrate carrier.
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. The system may be applied with a combination or carrier gases at multiple gas inlets, a combination of carrier and reactant gases at multiple inlets, and may be used with an arbitrarily large number of gases, when at least two gases of different molecular weights are provided. A linear flow pattern is achieved within the reactor, avoiding laminar recirculation areas, and permitting uniform deposition and growth of epitaxial layers on the substrate.
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:
A wafer carrier and methods of making the same for use in a system for growing epitaxial layers on one or more wafers by chemical vapor deposition. The wafer carrier includes wafer retention pockets recessed in its body. A thermally-insulating spacer is situated at least partially in the at least one wafer retention pocket and arranged to maintain a spacing between the peripheral wall surface and the wafer, the spacer being constructed from a material having a thermal conductivity less than a thermal conductivity of the wafer carrier such that the spacer limits heat conduction from portions of the wafer carrier body to the wafer. The wafer carrier further includes a spacer retention feature that engages with the spacer and includes a surface oriented to prevent centrifugal movement of the spacer when subjected to rotation about the central axis.
Abstract:
A linear cluster deposition system includes a plurality of reaction chambers positioned in a linear horizontal arrangement. First and second reactant gas manifolds are coupled to respective process gas input port of each of the reaction chambers. An exhaust gas manifold having a plurality of exhaust gas inputs is coupled to the exhaust gas output port of each of the plurality of reaction chambers. A substrate transport vehicle transports at least one of a substrate and a substrate carrier that supports at least one substrate into and out of substrate transfer ports of each of the reaction chambers. At least one of a flow rate of process gas into the process gas input port of each of the reaction chambers and a pressure in each of the reaction chambers being chosen so that process conditions are substantially the same in at least two of the reaction chambers.
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. The system may be applied with a combination or carrier gases at multiple gas inlets, a combination of carrier and reactant gases at multiple inlets, and may be used with an arbitrarily large number of gases, when at least two gases of different molecular weights are provided. A linear flow pattern is achieved within the reactor, avoiding laminar recirculation areas, and permitting uniform deposition and growth of epitaxial layers on the substrate.
Abstract:
A gas injection system for a chemical vapor deposition system includes a gas manifold comprising a plurality of valves where each of the plurality of valves has an input that is coupled to a process gas source and an output for providing process gas. Each of a plurality of gas injectors has an input that is coupled to the output of one of the plurality of valves and an output that is positioned in one of a plurality of zones in a chemical vapor deposition reactor. A controller having a plurality of outputs where each of the plurality of outputs is coupled to a control input of one of the plurality of valves. The controller instructs at least some of the plurality of valves to open at predetermined times to provide a desired gas flow to each of the plurality of zones in the chemical vapor deposition reactor.
Abstract:
A method of modifying a substrate carrier to improve process performance includes depositing material or fabricating devices on a substrate supported by a substrate carrier. A parameter of layers deposited on the substrate is then measured as a function of their corresponding positions on the substrate carrier. The measured parameter of at least some devices fabricated on the substrate or a property of the deposited layers is related to a physical characteristic of substrate carrier to obtain a plurality of physical characteristics of the substrate carrier corresponding to a plurality of positions on the substrate carrier. The physical characteristic of the substrate carrier is then modified at one or more of the plurality of corresponding positions on the substrate carrier to obtain desired parameters of the deposited layers or fabricated devices as a function of position on the substrate carrier.
Abstract:
A method of modifying a substrate carrier to improve process performance includes depositing material or fabricating devices on a substrate supported by a substrate carrier. A parameter of layers deposited on the substrate is then measured as a function of their corresponding positions on the substrate carrier. The measured parameter of at least some devices fabricated on the substrate or a property of the deposited layers is related to a physical characteristic of substrate carrier to obtain a plurality of physical characteristics of the substrate carrier corresponding to a plurality of positions on the substrate carrier. The physical characteristic of the substrate carrier is then modified at one or more of the plurality of corresponding positions on the substrate carrier to obtain desired parameters of the deposited layers or fabricated devices as a function of position on the substrate carrier.
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.