Abstract: An indirectly heated cathode ion source includes an arc chamber housing that defines an arc chamber, an indirectly heated cathode and a filament for heating the cathode. The cathode may include an emitting portion having a front surface, a rear surface and a periphery, a support rod attached to the rear surface of the emitting portion, and a skirt extending from the periphery of the emitting portion. A cathode assembly may include the cathode, a filament and a clamp assembly for mounting the cathode and the filament in a fixed spatial relationship and for conducting electrical energy to the cathode and the filament. The filament is positioned in a cavity defined by the emitting portion and the skirt of the cathode. The ion source may include a shield for inhibiting escape of electrons and plasma from a region outside the arc chamber in proximity to the filament and the cathode.

Abstract: A Faraday dose and uniformity monitor can include a magnetically suppressed annular Faraday cup surrounding a target wafer. A narrow aperture can reduce discharges within Faraday cup opening. The annular Faraday cup can have a continuous cross section to eliminate discharges due to breaks. A plurality of annular Faraday cups at different radii can independently measure current density to monitor changes in plasma uniformity. The magnetic suppression field can be configured to have a very rapid decrease in field strength with distance to minimize plasma and implant perturbations and can include both radial and azimuthal components, or primarily azimuthal components. The azimuthal field component can be generated by multiple vertically oriented magnets of alternating polarity, or by the use of a magnetic field coil. In addition, dose electronics can provide integration of pulsed current at high voltage, and can convert the integrated charge to a series of light pulses coupled optically to a dose controller.

Abstract: An apparatus is provided for handling workpieces, such as semiconductor wafers, during semiconductor processing. The apparatus includes a wafer platen having a plurality of channels each extending from a top surface to a bottom surface of the wafer platen, a plurality of lift pins in alignment with the channels, and a mechanism for engaging the lift pins in a loading position of the workpiece, a clamping position of the workpiece so that desired semiconductor processes may be performed to the workpiece, and a lift off position for removing the workpiece from the wafer platen after the semiconductor processes are completed. The mechanism places the lift pins below the surface of the wafer platen in the load position and then raises the lift pins to a first predetermined distance above the surface of the wafer platen in the clamp position such that the first predetermined distance allows the workpiece to be clamped to the wafer platen.

Abstract: An apparatus is provided for handling workpieces, such as semiconductor wafers, during semiconductor processing. The apparatus includes a wafer platen having a plurality of channels each extending from a top surface to a bottom surface of the wafer platen, a plurality of lift pins in alignment with the channels, and a mechanism for engaging the lift pins in a loading position of the workpiece, a clamping position of the workpiece so that desired semiconductor processes may be performed to the workpiece, and a lift off position for removing the workpiece from the wafer platen after the semiconductor processes are completed. The mechanism places the lift pins below the surface of the wafer platen in the load position and then raises the lift pins to a first predetermined distance above the surface of the wafer platen in the clamp position such that the first predetermined distance allows the workpiece to be clamped to the wafer platen.

Abstract: A magnet assembly is provided for use with an ion beam. The magnet assembly includes a magnet disposed in the path of the ion beam and an electron source. The magnet includes first and second polepieces spaced apart to define a magnet gap through which the ion beam is transported. The electron source is disposed on or in proximity to at least one of the polepieces for producing low energy electrons in the magnet gap. The electron source may include a one or two dimensional array of electron emitters or one or more linear electron emitters, for example. The magnet assembly may be utilized in an ion implanter to limit space charge expansion of the ion beam in the magnet gap.

Abstract: A magnet assembly is provided for use with an ion beam. The magnet assembly includes a magnet disposed in the path of the ion beam and an electron source. The magnet includes first and second polepieces spaced apart to define a magnet gap through which the ion beam is transported. The electron source is disposed on or in proximity to at least one of the polepieces for producing low energy electrons in the magnet gap. The electron source may include a one or two dimensional array of electron emitters or one or more linear electron emitters, for example. The magnet assembly may be utilized in an ion implanter to limit space charge expansion of the ion beam in the magnet gap.

Abstract: An indirectly heated cathode ion source includes an arc chamber housing that defines an arc chamber, an indirectly heated cathode and a filament for heating the cathode. The cathode may include an emitting portion having a front surface, a rear surface and a periphery, a support rod attached to the rear surface of the emitting portion, and a skirt extending from the periphery of the emitting portion. A cathode assembly may include the cathode, a filament and a clamp assembly for mounting the cathode and the filament in a fixed spatial relationship and for conducting electrical energy to the cathode and the filament. The filament is positioned in a cavity defined by the emitting portion and the skirt of the cathode. The ion source may include a shield for inhibiting escape of electrons and plasma from a region outside the arc chamber in proximity to the filament and the cathode.

Abstract: Methods and apparatus are provided for efficiently operating an ion implanter which includes a charged particle accelerator in a high energy mode and in a low energy mode. The charged particle accelerator includes a high voltage power supply, an accelerator column coupled to the high voltage power supply and a switching assembly. The accelerator column includes a plurality of accelerator electrodes. The high voltage power supply is disabled from energizing the accelerator column in the low energy mode. The switching assembly includes switching elements for electrically connecting the accelerator electrodes to a reference potential in the low energy mode and for electrically isolating the accelerator electrodes from the reference potential in the high energy mode. The switching assembly prevents positive potentials on the accelerator electrodes and thus minimizes space charge expansion of the beam when transporting positive ion beams in the low energy mode.

Abstract: Methods and apparatus are provided for plasma doping of a workpiece. The plasma doping apparatus includes a housing defining a plasma doping chamber, a platen for supporting a workpiece in the plasma doping chamber, an anode spaced from the platen in the plasma doping chamber, a process gas source coupled to the plasma doping chamber, a vacuum vessel enclosing the plasma doping chamber and defining an outer chamber, a primary vacuum pump connected to the vacuum vessel, a pulse source for applying pulses to the anode, and a controller. The controller establishes a controlled plasma doping environment in the plasma doping chamber in a first mode, typically a plasma doping mode, and establishes a gas connection between the plasma doping chamber and the outer chamber in a second mode, typically a vacuum pumping and wafer exchange mode.

Abstract: Plasma doping apparatus includes a plasma doping chamber, a platen mounted in the plasma doping chamber for supporting a workpiece such as a semiconductor wafer, a source of ionizable gas coupled to the chamber, an anode spaced from the platen and a pulse source for applying voltage pulses between the platen and the anode. The voltage pulses produce a plasma having a plasma sheath in the vicinity of the workpiece. The voltage pulses accelerate positive ions across the plasma sheath toward the platen for implantation into the workpiece. The plasma doping apparatus includes at least one Faraday cup positioned adjacent to the platen for collecting a sample of the positive ions accelerated across the plasma sheath. The sample is representative of the dose of positive ions implanted into the workpiece. The Faraday cup may include a multi-aperture cover for reducing the risk of discharge within the interior chamber of the Faraday cup.

Abstract: Methods and apparatus are provided for efficiently operating an ion implanter which includes a charged particle accelerator in a high energy mode and in a low energy mode. The charged particle accelerator includes a high voltage power supply, an accelerator column coupled to the high voltage power supply and a switching assembly. The accelerator column includes a plurality of accelerator electrodes. The high voltage power supply is disabled from energizing the accelerator column in the low energy mode. The switching assembly includes switching elements for electrically connecting the accelerator electrodes to a reference potential in the low energy mode and for electrically isolating the accelerator electrodes from the reference potential in the high energy mode. The switching assembly prevents positive potentials on the accelerator electrodes and thus minimizes space charge expansion of the beam when transporting positive ion beams in the low energy mode.

Abstract: Plasma doping apparatus includes a plasma doping chamber, a platen mounted in the plasma doping chamber for supporting a workpiece such as a semiconductor wafer, a source of ionizable gas coupled to the chamber, an anode spaced from the platen and a pulse source for applying high voltage pulses between the platen and the anode. The high voltage pulses produce a plasma having a plasma sheath in the vicinity of the workpiece. The high voltage pulses accelerate positive ions across the plasma sheath toward the platen for implantation into the workpiece. The plasma doping apparatus includes at least one Faraday cup positioned adjacent to the platen for collecting a sample of the positive ions accelerated across the plasma sheath. The sample is representative of the dose of positive ions implanted into the workpiece.

Abstract: Apparatus for providing thermal transfer between a semiconductor wafer and a heat sink or source in a vacuum processing chamber includes a platen against which the wafer is sealed to define a thermal transfer region therebetween. The platen includes a passage for gas flow between the chamber and the thermal transfer region and a conduit for circulation of a cooling fluid. The platen further includes a fluid-actuated valve responsive to the pressure of the cooling fluid for closing the passage. When the pressure in the chamber reaches a predetermined value, the cooling fluid is turned on and closes the valve. Gas at the predetermined pressure, typically in the range of 0.5 to 100 Torr, is trapped in the thermal transfer region and conducts thermal energy. In a preferred embodiment, a plurality of platens are positioned on a rotating disc in an ion implantation system.