Abstract:
An electrostatic chuck for holding an article to be processed in a plasma reaction chamber and comprising a metal pedestal coated with a layer of dielectric material in which is formed a cooling gas distribution system for passing and distributing a cooling gas between the upper surface of the layer and the article when supported on the pedestal. The gas distribution system comprises a plurality of intersecting grooves formed entirely in the upper surface of the layer with small gas distribution holes through intersections of the grooves over upper ends of cooling gas receiving holes formed in an underside of the pedestal.
Abstract:
A method, and corresponding apparatus, for matching a generator impedance with an unknown and possibly changing load impedance, to maximize power transferred to the load. The apparatus includes an impedance matching network, and a network model, to estimate the load impedance from known present network values and a measurement of network input impedance, and to estimate optimum network values from the input impedance and the estimated load impedance. A controller computes new network values based on the present and optimum values, and outputs the new values to the network. The process is repeated using the new network values to estimate the load impedance and generate a new set of optimum values. The controller uses a control equation with parameters selected to ensure rapid convergence on the maximum-power condition, without overshoot or instability. Preferably, current and voltage measurements are made in the network to enable correction of the network values based on these measurements on the actual network. Although the invention may be used with any type of variable-impedance network hardware, preferably current-controlled inductances are used as the variable network impedances.
Abstract:
A matching network matches an output impedance of a source with an input impedance of a load. The matching network includes a plurality of transmission line stubs. Each transmission line stub includes a first transmission line conductor, a second transmission line conductor running parallel to but not in electrical contact with the first transmission line conductor, and ferrite dielectric material between the first transmission line conductor and the second transmission line conductor. A magnetic field is used to vary the relative permeability of the ferrite dielectric material.
Abstract:
A matching network matches an output impedance of a generator with an input impedance of a load. The matching network includes a first variable impedance element, a second variable impedance element, a reflected power detector and a control circuit. Each of the first variable impedance elements are constructed using magnetically saturable reactors. For example, each magnetically saturable reactor may be a transformer composed of primary and secondary windings wound around a non-linear ferromagnetic core. The reflected power detector detects power reflected from the matching network to the generator. The control circuit receives from the reflected power detector a signal which represents the changes in reflected power. Using this feedback the control means varies the impedance through the first variable impedance element and the second variable impedance element until the reflected power is negligible. The control circuit then separates out the component of the change in reflected power which is due to dithering of the first variable impedance element from the change in reflected power which is due to dithering of the second variable impedance element. Using the components of change, the control circuit continuously varies the steady state impedance of the first variable impedance and the steady state impedance of the second variable impedance in directions which minimize the reflected power.
Abstract:
The disclosure pertains to a capactively coupled plasma source in which VHF power is applied through an impedance-matching coaxial resonator having a folded structure and symmetrical power distribution.
Abstract:
Embodiments of the present invention provide methods and apparatus for analyzing thermal properties of bonding materials within a composite structure. One embodiment of the present invention provides an apparatus for analyzing thermal property of a bonding material within a structure. The apparatus comprises a structure support having a supporting surface configured to support the structure, a heat source configured to direct a heat flux to the structure supported by the supporting surface of the structure support, and a camera facing the structure supported on the structure support and configured to capture thermal images of the structure supported on the structure support.
Abstract:
In a plasma reactor having an electrostatic chuck, wafer voltage may be determined from RF measurements at the bias input using previously determined constants based upon transmission line properties of the bias input, and this wafer voltage may be used to accurately control the DC wafer clamping voltage.
Abstract:
A method of creating a plasma-resistant thermal oxide coating on a surface of an article, where the article is comprised of a metal or metal alloy which is typically selected from the group consisting of yttrium, neodymium, samarium, terbium, dysprosium, erbium, ytterbium, scandium, hafnium, niobium or combinations thereof. The oxide coating is formed using a time-temperature profile which includes an initial rapid heating rage, followed by a gradual decrease in heating rate, to produce an oxide coating structure which is columnar in nature. The grain size of the crystals which make up the oxide coating is larger at the surface of the oxide coating than at the interface between the oxide coating and the metal or metal alloy substrate, and the oxide coating is in compression at the interface between the oxide coating and the metal or metal alloy substrate.
Abstract:
Embodiments of the present invention provide methods and apparatus for analyzing thermal properties of bonding materials within a composite structure. One embodiment of the present invention provides an apparatus for analyzing thermal property of a bonding material within a structure. The apparatus comprises a structure support having a supporting surface configured to support the structure, a heat source configured to direct a heat flux to the structure supported by the supporting surface of the structure support, and a camera facing the structure supported on the structure support and configured to capture thermal images of the structure supported on the structure support.