Abstract: A plasma processor for a workpiece includes a coil for supplying an r.f. exciting field through a window to a plasma in a vacuum chamber. A powered non-magnetic metal member between the coil and plasma couples the field to the plasma. In first and second embodiments, the metal member is respectively (1) a plate abutting a face of the window inside the chamber and (2) a thin film on an interior face of the window. In a third embodiment, the plate and film are both used. All embodiments help to ignite the plasma. The second embodiment increases plasma stability and prevents window clouding by ionized plasma particles. Metal from the plate is sputtered as a deposit onto the workpiece. The third embodiment enables substantially simultaneous depositing and cleaning.

Abstract: A plasma processing module for processing a substrate includes a plasma containment chamber having a feed gas inlet port capable of allowing a feed gas to enter the plasma containment chamber of the plasma processing module during the processing of the substrate. An inductively coupled source is used to energize the feed gas and striking a plasma within the plasma containment chamber. The specific configuration of the inductively coupled source causes the plasma to be formed such that the plasma includes a primary dissociation zone within the plasma containment chamber. A secondary chamber is separated from the plasma containment chamber by a plasma containment plate. The secondary chamber includes a chuck and an exhaust port. The chuck is configured to support the substrate during the processing of the substrate and the exhaust port is connected to the secondary chamber such that the exhaust port allows gases to be removed from the secondary chamber during the processing of the substrate.

Abstract: A method and apparatus is disclosed for controlling the pressure of a reaction chamber in wafer processing equipment. The disclosed apparatus and method uses a ballast port for inserting gas into the evacuation system, thereby controlling the pressure in the reaction chamber. The disclosed apparatus and method further uses estimation curves to estimate the desired position of a controlled gate valve which is located between the reaction chamber and turbo pump. The disclosed apparatus and method achieves a set point pressure by prepositioning a throttle valve followed by repositioning the throttle valve based on the difference between a measure pressure and the set point pressure using proportional and integral control, wherein enablement of integral control is delay for a pre-specified period.

Abstract: A planar coil exciting a plasma of an r.f. vacuum plasma processor for a workpiece processed surface in a chamber includes plural turns. The coil, chamber and workpiece are arranged to produce in the chamber a magnetic flux having substantially greater density in peripheral portions of the coil and chamber than in a center portion of the chamber and coil so a substantially uniform plasma flux is incident on a processed surface of the workpiece.

Abstract: A gas in a vacuum plasma processing chamber is ignited to a plasma by subjecting the gas to an r.f. field derived from an r.f. source having a frequency and power level sufficient to ignite the gas into the plasma and to maintain the plasma. The r.f. field is supplied to the gas by a reactive impedance element connected via a matching network to the r.f. source. The matching network includes first and second variable reactances that control loading of the source and tuning a load, including the reactive impedance element and the plasma, to the source. The value of only one of the reactances is varied until a local maximum of a function of power coupled between the source and the load is reached. The value of only the other reactance is varied until a local maximum of the function is reached. The two varying steps are then repeated as necessary.

Abstract: A substantially planar coil of a vacuum plasma processor has plural turns for exciting gas in the processor to a plasma state in response to r.f. coil energization. The coil is located outside the processor and surrounded by a shield tending to cause magnetic flux coupled from peripheral portions of the coil to the gas to be less than magnetic flux coupled from interior portions of the coil to the gas. The coil is arranged so magnetic flux derived from a center portion of an area circumscribed by the coil is less than the magnetic flux derived from all other areas circumscribed by the coil. The magnetic flux is such that the density of the plasma in the processor on a processed substrate is relatively uniform even though the coil exhibits transmission line properties so there are substantial peak-to-peak current variations along the length of the coil.

Abstract: A load including a plasma discharge in a plasma processing chamber is matched to a variable frequency source so the power reflected from the load is substantially minimized. The source voltage or a variable reactance of a matching network between the source and load is controlled so the load has a preset power level, as detected by the difference between the source output power and the power reflected from the load.

Abstract: A dielectric workpiece is clamped to a holder in a vacuum plasma processor chamber by applying the plasma to a surface of the workpiece exposed to the plasma simultaneously with applying a relatively high voltage to an electrode on the holder. The electrode is in close proximity to a portion of the workpiece not exposed to the plasma so (1) the electrode is at a voltage substantially different from the plasma, (2) electrostatic charge is applied to the exposed surface by the plasma, and (3) an electrical conducting path is provided via the plasma from the electrostatic charge to a terminal at a potential substantially different from the voltage applied to the electrode. Sufficient electrostatic clamping force is applied through the thickness of the workpiece by a voltage difference between the DC voltage applied to a single electrode and charge applied by the plasma to the exposed face to hold the substrate on the holder.

Abstract: A method and apparatus is disclosed for controlling the pressure of reaction chamber in wafer processing equipment. The disclosed apparatus and method uses a ballast port for inserting gas into the evacuation system, thereby controlling the pressure in the reaction chamber. The disclosed apparatus and method further uses estimation curves to estimate the desired position of a controlled gate valve which is located between the reaction chamber and turbo pump. The disclosed apparatus and method further introduces process gases at higher rate than set point levels to reduce the transition time or stabilization time required when raising the pressure in the reaction chamber.

Abstract: A substantially planar coil of a vacuum plasma processor has plural turns for exciting gas in the processor to a plasma state in response to r.f. coil energization. The coil is located outside the processor and surrounded by a shield tending to cause magnetic flux coupled from peripheral portions of the coil to the gas to be less than magnetic flux coupled from interior portions of the coil to the gas. The coil is arranged so magnetic flux derived from a center portion of an area circumscribed by the coil is less than the magnetic flux derived from all other areas circumscribed by the coil. The magnetic flux is such that the density of the plasma in the processor on a processed substrate is relatively uniform even though the coil exhibits transmission line properties so there are substantial peak-to-peak current variations along the length of the coil.

Abstract: A load including a plasma discharge in a vacuum plasma processing chamber is matched to an r.f. source that supplies sufficient power to the discharge to maintain the discharge. A matching network connected between the source and a plasma excitation component of the chamber includes first and second variable reactances. A microprocessor causes the value of the first reactance to be varied while the value of the other reactance stays constant until power reflected from the load to output terminals of the source is minimized. The microprocessor causes the value of the second reactance to then be varied while the value of the first reactance stays constant until reflected power is minimized. The reactance values are alternately changed until the reflected minimum power does not change, at which time there is a match. To initiate the discharge, the microprocessor causes the value of the one reactance to change while the value of the other reactance stays constant.

Abstract: A planar coil exciting a plasma of an r.f. vacuum plasma processor for a workpiece processed surface in a chamber includes plural turns. The coil, chamber and workpiece are arranged to produce in the chamber a magnetic flux having substantially greater density in peripheral portions of the coil and chamber than in a center portion of the chamber and coil so a substantially uniform plasma flux is incident on a processed surface of the workpiece.

Abstract: A method and apparatus is disclosed for controlling the pressure of reaction chamber in wafer processing equipment. The disclosed apparatus and method uses a ballast port for inserting gas into the evacuation system, thereby controlling the pressure in the reaction chamber. The disclosed apparatus and method further uses estimation curves to estimate the desired position of a controlled gate valve which is located between the reaction chamber and turbo pump. The disclosed apparatus and method further introduces process gases at higher rate than set point levels to reduce the transition time or stabilization time required when raising the pressure in the reaction chamber.

Abstract: An r.f. field is supplied by a reactive impedance element to a plasma in a vacuum plasma processing chamber. The element and source are connected via a matching network including first and second variable reactances that control loading of the source and tuning a load, including the reactive impedance element and the plasma, to the source. The values of the first and second variable reactances are changed to determine the amount the first variable reactance is to change for each unit change of the second variable reactance to attain the best match between the impedances seen looking into and out of output terminals of the r.f. source. Then the values of the first and second variable reactances are varied simultaneously based on the determination until the best impedance match between the impedances seen looking into and out of output terminals of the r.f. source is attained.

Abstract: Surfaces having semiconductor oxides, metal oxides and hydrocarbons deposited thereon in a vacuum plasma processing chamber are in situ cleaned by introducing water vapor and SF.sub.6 and/or NF.sub.3 gas in the presence of a plasma discharge. The vapor and gas react to form gaseous HF, and an acidic gas including at least one of H.sub.2 SO.sub.4 and HNO.sub.3. The discharge ionizes and dissociates the HF and acidic gases to form gaseous reactants for the deposits. The reactants chemically react with the deposits, including the oxides and hydrocarbons, to vaporize these deposits. The vaporized deposits are pumped out of the chamber by the same pump which normally evacuates the chamber to a vacuum. Oxygen and/or H.sub.2 O.sub.2 vapors are introduced in the presence of the plasma to additionally clean the surfaces.

Abstract: A determination of whether a workpiece is properly positioned on an electrostatic chuck in a vacuum plasma processing chamber is made by measuring the capacitance across a pair of electrodes of the chuck. If the chuck is properly positioned, the workpiece is held in situ on the chuck by applying a DC voltage to the chuck. The workpiece is then processed by the plasma.

Abstract: An electrostatic chuck is disclosed that is resistant to the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck. A guard ring surrounds the chuck and floats close to the self-bias potential induced by the plasma on the wafer. The voltage between the wafer and the closest electrode is thereby capacitively divided by the guard ring.

Abstract: An electrostatic chuck has its electrodes biased with respect to the self-bias potential induced by the plasma on the wafer, thereby providing improved resistance to breakdown in spite of variation of the wafer potential during processing. An alternate embodiment further suppresses the formation of vacuum arcs between the back of the wafer being processed and the body of the chuck by the interposition of a conductive guard ring at the self-bias potential, thereby defining an equipotential area between the closest electrode and the wafer.

Abstract: A method and apparatus for reducing particulates in a plasma tool using steady state flows includes a device, operatively coupled to a housing in which an object to be processed is positioned, for generating a plasma flow adjacent the object toward a pumping aperture. A pumping mechanism pumps a medium adjacent the object. The medium supports the plasma and entrains particulates in the plasma away from the object and out the pumping aperture. Magnetic fields, produced by multipole magnets forming a ring cusp, are preferably used to produce the plasma flow which is directed radially away from the object to be processed. In a second embodiment, an array of magnets which form a line cusp is provided to produce an opening through which plasma will flow.

Abstract: An electrostatic chuck is made by a method in which the component parts are machined, then anodized to provide a hard insulating surface, and then assembled in a fixture, to provide a planar surface for wafer support that retains superior insulating properties; gas may be fed from the rim only, diffusing within interstices between the clamping surface and the wafer and maintaining a desired pressure by flowing radially through an impedance determined by the average spacing between clamping surface and wafer, thereby providing uniform pressure across the clamping surface without the use of elastomeric seals.