Abstract: A dielectric etch process applicable etching a dielectric layer with an underlying stop layer. It is particularly though not necessarily applicable to forming a dual-damascene interconnect structure by a counterbore process, in which a deep via is etched prior to the formation of a trench connecting two of more vias. A single metallization fills the dual-damascene structure. The substrate is formed with a lower stop layer, a lower dielectric layer, an upper stop layer, and an upper dielectric layer. For example, the dielectric layers may be silicon dioxide, and the stop layers, silicon nitride. The initial deep via etch includes at least two substeps. A first substep includes a non-selective etch through the upper stop layer followed by a second substep of selectively etching through the lower dielectric layer and stopping on the lower stop layer. The first substep may be preceded by yet another substep including a selective etch part ways through the upper dielectric layer.

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 dielectric etch process applicable etching a dielectric layer with an underlying stop layer. It is particularly though not necessarily applicable to forming a dual-damascene interconnect structure by a counterbore process, in which a deep via is etched prior to the formation of a trench connecting two of more vias. A single metallization fills the dual-damascene structure. The substrate is formed with a lower stop layer, a lower dielectric layer, an upper stop layer, and an upper dielectric layer. For example, the dielectric layers may be silicon dioxide, and the stop layers, silicon nitride. The initial deep via etch includes at least two substeps. A first substep includes a non-selective etch through the upper stop layer followed by a second substep of selectively etching through the lower dielectric layer and stopping on the lower stop layer. The first substep may be preceded by yet another substep including a selective etch part ways through the upper dielectric layer.

Abstract: A dielectric etch process particularly applicable to forming a dual-damascene interconnect structure by a counterbore process, in which a deep via is etched prior to the formation of a trench connecting two of more vias. A single metallization fills the dual-damascene structure. The substrate is formed with a lower stop layer, a lower dielectric layer, an upper stop layer, and an upper dielectric layer. For example, the dielectric layers may be silicon dioxide, and the stop layers, silicon nitride. The initial deep via etch includes at least two substeps. A first substep includes a non-selective etch through the upper stop layer followed by a second substep of selectively etching through the lower dielectric layer and stopping on the lower stop layer. The first substep may be preceded by yet another substep including a selective etch part ways through the upper dielectric layer.

Abstract: A plasma etch process, particularly applicable to a self-aligned contact etch or other advanced structures requiring high-selectivity to nitride or other non-oxide materials and producing no etch stop. The process is preferably performed in a high-density plasma reactor for etching holes with either high or low aspect rations. In this process, hexafluoropropylene (C3F6) is the principal etching gas and another hydrofluorocarbon such as CH2F2 or C3H2F6 is added at least in part for its polymer-forming ability, which increases selectivity of etching oxide to nitride. The process gas also includes a substantial amount of an inactive gas such as argon. The process gas mixture can be balanced between the active etching gas and the polymer former in proportions to optimize selectivity over other materials without the occurrence of etch stop in narrow contact holes and with a wide process window.

Abstract: A process for etching an oxidized organo-silane film exhibiting a low dielectric constant and having a most preferred atomic composition of 52% hydrogen, 8% carbon, 19% silicon, and 21% oxygen. The process of etching deep holes in the organo-silane film while stopping on a nitride or other non-oxide layer is preferably performed in an inductively coupled high-density plasma reactor with a main etching gas mixture of a fluorocarbon, such as C4F8, and argon while the pedestal electrode supporting the wafer is RF biased. For very deep and narrow holes, oxygen or nitrogen may be added to volatize carbon. In an integrated process in which an oxygen plasma is used either for the film etching or for post-etch treatments such as ashing or nitride removal, the oxygen plasma should be excited only when no RF bias is applied to the pedestal electrode, and thereafter the sample should be annealed in an inert environment to recover the low dielectric constant.

Abstract: A superb centrifugal flotation cell with a rotating feed, is provided for use in an effective separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary pipe and a rotating feed line comprising a centrifugal rotating downfeeder. The slurry is centrifugally discharged from the rotating downfeeder into the flotation chamber where the slurry is separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles for further processing.

Abstract: A plasma etch process, particularly applicable to a self-aligned contact etch or other advanced structures requiring high-selectivity to nitride or other non-oxide materials and no etch stop. The process is preferably performed in a high-density plasma reactor for etching holes with either high or low aspect rations. In this process, hexafluoropropane (C.sub.3 H.sub.2 F.sub.6) is the principal etching gas in the presence of a substantial amount of an inactive gas such as argon. The process can also be used with the closely related gases heptafluoropropane (C.sub.3 HF.sub.7) and pentafluoropropane (C.sub.3 H.sub.3 F.sub.5). The process may use one or more of the these gases in proportions to optimize selectivity over other materials without the occurrence of etch stop in narrow contact holes and with a wide process window. Difluoromethane (CH.sub.2 F.sub.2) or other fluorocarbons may be combined with the above gases for optimum selectivity for a design of a specific contact feature.

Abstract: A user-friendly centrifugal flotation cell with a rotating drum, is provided for use in an efficient separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary downfeeder to a centrifuge comprising a rotating flotation cell. The aerated slurry is centrifugally separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles. The froth is processed by froth flotation in a froth flotation chamber.

Abstract: An oxide etch process that is highly selective to nitride, thereby being beneficial for a self-aligned contact etch of silicon dioxide to an underlying thin layer of silicon nitride. The process uses difluoromethane (CH.sub.2 F.sub.2) for its strong polymer forming and a greater amount of trifluoromethane (CHF.sub.3) for its strong etching, and with a high diluent fraction of argon (Ar). The etch process is performed at a low pressure of about 20 milliTorr in a high-density plasma etching chamber.

Abstract: A user-friendly centrifugal flotation cell with a rotating drum, is provided for use in an efficient separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary downfeeder to a centrifuge comprising a rotating flotation cell. The aerated slurry is centrifugally separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles. The froth is processed by froth flotation in a froth flotation chamber.

Abstract: A superb centrifugal flotation cell with a rotating feed, is provided for use in an effective separation process to rapidly recover greater quantities of valuable fine particles. In the process, a slurry of fine particles is injected with air bubbles and moved downwardly through a stationary pipe and a rotating feed line comprising a centrifugal rotating downfeeder. The slurry is centrifugally discharged from the rotating downfeeder into the flotation chamber where the slurry is separated into a waste stream of non-floating gangue material and a particulate-enriched froth comprising air bubbles carrying a substantial amount of the valuable fine particles for further processing.

Abstract: Additives for high alumina cement compositions are proposed. The additives are effective to reduce or prevent the deleterious conversion of hexagonal calcium aluminate hydrates to cubic hydrogarnet in the high alumina cement compositions. The additives comprise 80-99 wt. % of a siliceous pozzolan and 1-20 wt. % of an inorganic sodium or potassium salt.

Abstract: An electrostatic chuck for holding a wafer in a plasma processing chamber, the chuck including a pedestal having a top surface, an internal manifold for carrying a cooling gas, and a first plurality of holes leading from the internal manifold toward said top surface; and a dielectric layer on the top surface of the pedestal. The dielectric layer has a top side and second plurality of holes, each of which is aligned with a different one of the holes of the first plurality of holes in the pedestal. The first and second holes form a plurality of passages extending from the internal manifold to the top side of the dielectric layer and through which the cooling gas is supplied to the backside of the wafer. Each of the first holes and the second hole aligned therewith form a different one of the plurality of passages.

Abstract: Improvements in a wafer support apparatus used for electrostatic clamping of a wafer to the wafer support, and a method of making same, are disclosed wherein a dielectric material, formed on the surface of a wafer support facing the wafer to facilitate the electrostatic clamping, has a protective coating formed over the dielectric material to provide protection to the dielectric material against chemical attack from chemicals used during the processing of the semiconductor wafer. In a preferred embodiment, the protective coating comprises an aluminum compound, such as an oxide of aluminum or aluminum nitride, having a thickness ranging from about 1 micron to about 30 microns, but not exceeding about 50% of the thickness of the dielectric material so as to not interfere with the electrostatic charge used for clamping the wafer to the wafer support.

Abstract: An electrostatic chuck for holding a wafer in a plasma processing chamber, the chuck including a pedestal having a top surface, an internal manifold for carrying a cooling gas, and a first plurality of holes leading from the internal manifold toward said top surface; and a dielectric layer on the top surface of the pedestal. The dielectric layer has a top side and second plurality of holes, each of which is aligned with a different one of the holes of the first plurality of holes in the pedestal. The first and second holes form a plurality of passages extending from the internal manifold to the top side of the dielectric layer and through which the cooling gas is supplied to the backside of the wafer. Each of the first holes and the second hole aligned therewith form a different one of the plurality of passages.

Abstract: Lightweight concrete products, useful for example in blocks, wall panels, floor and roof slabs, in which zeolite is a major component, its content in the cementing material of the products exceeding 50 wt. %. Depending on application, zeolite may be non-treated or calcined at a temperature enabling the surface activation of the zeolite and resulting high surface energy. Zeolite thus treated will work as both pozzolanic material and bubble-generating agent. Strengthening agents are used to improve compressive strength of the products. Also, a binding material, useful for hazardous waste stabilization, comprising zeolite as a major component, is proposed.

Abstract: The invention is embodied in a method of determining an optimum de-chucking voltage for nullifying residual electrostatic forces on a wafer in an electrostatic chuck for removal of the wafer from the chuck, including holding the wafer on the electrostatic chuck by applying an electrostatic potential to the chuck, introducing a gas between the wafer and the chuck, reducing the electrostatic potential of the chuck while observing a rate of leakage of the gas from between the wafer and the chuck, and recording as the optimum dechucking voltage the value of the electrostatic potential obtaining when the rate of leakage exceeds a predetermined threshold.