Abstract: A plasma etching process, particularly useful for selectively etching oxide over a feature having a non-oxide composition, such as silicon nitride and especially when that feature has a corner that is prone to faceting during the oxide etch. A primary fluorine-containing gas, preferably hexafluorobutadiene (C4F6), is combined with a significantly larger amount of the diluent gas xenon (Xe) enhance nitride selectivity without the occurrence of etch stop. The chemistry is also useful for etching oxides in which holes and corners have already been formed, for which the use of xenon also reduces faceting of the oxide. For this use, the relative amount of xenon need not be so high. The invention may be used with related heavy fluorocarbons and other fluorine-based etching gases.

Abstract: An RF power applicator of the reactor includes inner and outer conductive radial spokes. The set of inner conductive spokes extends radially outwardly from and is electrically connected to the conductive post toward the conductive side wall. The set of outer conductive spokes extends radially inwardly toward the conductive post from and is electrically connected to the conductive side wall. In this way, the inner and outer sets of conductive spokes are electrically connected together, the combination of the inner and outer set of spokes with the conductive enclosure having a fundamental resonant frequency inversely proportional to the height of the conductive enclosure and the lengths of the inner and outer set of conductive spokes. An RF source power generator is coupled across the RF power applicator and has an RF frequency corresponding to the fundamental resonant frequency.

Abstract: An inductive antenna of a plasma reactor for processing a semiconductor wafer is connected to a radio frequency (RF) power source, and consists of a conductor arranged in successive loops that wind in opposing directions, adjacent pairs of the successive loops having facing portions in which current flow is parallel, the facing portions being sufficiently close to at least nearly share a common current path, whereby to form transitions across the facing portions between opposing magnetic polarizations.

Abstract: A plasma reactor for processing a semiconductor workpiece, includes a reactor chamber having a chamber ceiling and a chamber side wall and a workpiece support pedestal within the chamber, a process gas conduit and gas distribution orifices facing the interior of the chamber and coupled to the process gas conduit, a conductive enclosure outside of the chamber and overlying the ceiling and having a conductive side wall with a bottom edge supported on the chamber ceiling and a conductive ceiling supported on a top edge of the conductive side wall, and a conductive post extending parallel with the conductive side wall from a center portion of the conductive ceiling toward the chamber ceiling. An RF power applicator of the reactor includes inner and outer conductive radial spokes. The set of inner conductive spokes extends radially outwardly from and is electrically connected to the conductive post toward the conductive side wall.

Abstract: An inductive antenna of a plasma reactor for processing a semiconductor wafer is connected to a radio frequency (RF) power source, and consists of a conductor arranged in successive loops that wind in opposing directions, adjacent pairs of the successive loops having facing portions in which current flow is parallel, the facing portions being sufficiently close to at least nearly share a common current path, whereby to form transitions across the facing portions between opposing magnetic polarizations.

Abstract: A plasma etching process, particularly useful for selectively etching oxide over a feature having a non-oxide composition, such as silicon nitride and especially when that feature has a corner that is prone to faceting during the oxide etch. A primary fluorine-containing gas, preferably hexafluorobutadiene (C4F6), is combined with a significantly larger amount of the diluent gas xenon (Xe) to enhance nitride selectivity without the occurrence of etch stop. The chemistry is also useful for etching oxides in a time oxide etch in which holes and corners have already been formed, for example counterbore vias in a dual damascene structure. In this case, the relative amount of xenon need not be so high, but xenon still reduces faceting of the oxide corners. The invention may be used with related heavy fluorocarbons and other fluorine-based etching gases.

Abstract: A plasma etching process, particularly useful for selectively etching oxide over a feature having a non-oxide composition, such as silicon nitride and especially when that feature has a comer that is prone to faceting during the oxide etch. A primary fluorine- containing gas, preferably hexafluorobutadiene (C4F6), is combined with a significantly larger amount of the diluent gas xenon (Xe) enhance nitride selectivity without the occurrence of etch stop. The chemistry is also useful for etching oxides in which holes and comers have already been formed, for which the use of xenon also reduces faceting of the oxide. For this use, the relative amount of xenon need not be so high. The invention may be used with related heavy fluorocarbons and other fluorine-based etching gases.

Abstract: The invention is embodied in a method of processing a semiconductor workpiece in a plasma reactor chamber, including supplying a polymer and etchant precursor gas containing at least carbon and fluorine into the chamber at a first flow rate sufficient of itself to maintain a gas pressure in the chamber in a low pressure range below about 20 mT, supplying a relatively non-reactive gas into the chamber at second flow rate sufficient about one half or more of the total gas flow rate into the chamber, in combination with the first flow rate of the precursor gas, to maintain the gas pressure in the chamber in a high pressure range above 20 mT, and applying plasma source power into the chamber to form a high ion density plasma having an ion density in excess of 1010 ions per cubic centimeter.

Abstract: A low-temperature process for selectively etching oxide with high selectivity over silicon in a high-density plasma reactor. The principal etching gas is a hydrogen-free fluorocarbon, such as C.sub.2 F.sub.6 or C.sub.4 F.sub.8, to which is added a silane or similar silicon-bearing gas, e.g., the monosilane SiH.sub.4. The fluorocarbon and silane are added in a ratio within the range of 2 to 5, preferably 2.5 to 3. The process provides high polysilicon selectivity, high photoresist facet selectivity, and steep profile angles. Selectivity is enhanced by operating at high flow rates. Silicon tetrafluoride may be added to enhance the oxide etching rate. The process may operate at temperatures of chamber parts below 180.degree. C. and even down to 120.degree. C. The process enables the fabrication of a bi-level contact structure with a wide process window.