Abstract:
A method of measuring ion dose in a plasma immersion ion implantation reactor during ion implantation of a selected species into a workpiece includes placing the workpiece on a pedestal in the reactor and feeding into the reactor a process gas comprising a species to be implanted into the workpiece, and then coupling RF plasma source power to a plasma in the reactor. It further includes coupling RF bias power to the workpiece by an RF bias power generator that is coupled to the workpiece through a bias feedpoint of the reactor and measuring RF current at the feedpoint to generate a current-related value, and then integrating the current-related over time to produce an ion implantation dose-related value.
Abstract:
A method is provided in plasma processing of a workpiece for stabilizing the plasma against engineered transients in applied RF power, by modulating an unmatched low power RF generator in synchronism with the transient.
Abstract:
A plasma reactor for processing a workpiece such as a semiconductor wafer using predetermined transients of plasma bias power or plasma source power has unmatched low power RF generators synchronized to the transients to minimize transient-induced changes in plasma characteristics.
Abstract:
A method and apparatus for controlling plasma uniformity is disclosed. When etching a substrate, a non-uniform plasma may lead to uneven etching of the substrate. Impedance circuits may alleviate the uneven plasma to permit more uniform etching. The impedance circuits may be disposed between the chamber wall and ground, the showerhead and ground, and the cathode can and ground. The impedance circuits may comprise one or more of an inductor and a capacitor. The inductance of the inductor and the capacitance of the capacitor may be predetermined to ensure the plasma is uniform. Additionally, the inductance and capacitance may be adjusted during processing or between processing steps to suit the needs of the particular process.
Abstract:
Particulate generation has been a problem in semiconductor device processing in highly corrosive plasma environments. The problem is exacerbated when the plasma is a reducing plasma. Empirically produced data has shown that the formation of a plasma spray coated yttrium-comprising ceramic such as yttrium oxide, Y2O3—ZrO2 solid solution, YAG, and YF3 provides a low porosity coating with smooth and compacted surfaces when such ceramics are spray coated from a powder feed having an average effective diameter ranging from about 22 μm to about 0.1 μm. These spray-coated materials reduce the generation of particulates in corrosive reducing plasma environments.
Abstract:
A valve system having high maximum gas flow rate and fine control of gas flow rate, includes a valve housing for blocking gas flow through a gas flow path, a large area opening through said housing having a first arcuate side wall and a small area opening through said housing having a second arcuate side wall, and respective large area and small area rotatable valve flaps in said large area and small area openings, respectively, and having arcuate edges congruent with said first and second arcuate side walls, respectively and defining therebetween respective first and second valve gaps. The first and second valve gaps are sufficiently small to block flow of a gas on one side of said valve housing up to a predetermined pressure limit, thereby obviating any need for O-rings.
Abstract:
A method of processing a workpiece includes introducing an optical absorber material precursor gas into a chamber containing the workpiece, generating an RF oscillating toroidal plasma current in a reentrant path that includes a process zone overlying the workpiece by applying RF source power, so as to deposit a layer of an optical absorber material on the workpiece, and exposing the workpiece to optical radiation that is at least partially absorbed in the optical absorber layer.
Abstract:
A method is provided for processing a workpiece in a plasma reactor chamber having electrodes including at least a ceiling electrode and a workpiece support electrode. The method includes coupling respective RF power sources of respective VHF frequencies f1 and f2 to either (a) respective ones of the electrodes or (b) a common one of the electrodes, where f1 is sufficiently high to produce a center-high non-uniform plasma ion distribution and f2 is sufficiently low to produce a center-low non-uniform plasma ion distribution. The method further includes adjusting a ratio of an RF parameter at the f1 frequency to the RF parameter at the f2 frequency so as to control plasma ion density distribution, the RF parameter being any one of RF power, RF voltage or RF current.
Abstract:
A reactor is provided for removing polymer from a backside of a workpiece. The reactor includes a vacuum chamber having a ceiling, a floor and a cylindrical side wall. The reactor further includes workpiece support apparatus within the chamber configured for a workpiece to be placed thereon with its front side facing the ceiling. The support apparatus is configured to leave at least an annular periphery of the backside of the workpiece exposed. A confinement member defines a narrow gap with an outer edge of the workpiece, the narrow gap being on the order of about 1% of the workpiece diameter, the narrow gap corresponding to a boundary dividing the chamber between an upper process zone and a lower process zone, the reactor further comprising a vacuum pump coupled to the lower process zone. An external plasma-generating chamber is coupled to the chamber, the external plasma-generating chamber configured to introduce a plasma by-product into the lower process zone, and a supply of a polymer etch precursor gas to the external plasma-generating chamber. The ceiling includes a gas distribution plate facing the upper process zone, the reactor further comprising a purge gas supply coupled to the gas distribution plate.
Abstract:
A plasma reactor includes a ceiling electrode facing a workpiece support pedestal and a pedestal electrode in the pedestal and first and second VHF power sources of different frequencies coupled to the same or to different ones of the ceiling electrode and the pedestal electrode. The first and second VHF power sources are of sufficiently high and sufficiently low frequencies, respectively, to produce center-high and center-low plasma distribution non-uniformities, respectively, in the chamber. The reactor further includes a controller programmed to change the relative output power levels of the first and second VHF power sources to: (a) increase the relative output power level of the first VHF power source whenever plasma ion distribution has a predominantly edge-high non-uniformity, and (b) increase the relative output power level of the second VHF power source whenever plasma ion distribution has a predominantly center-high non-uniformity.