Abstract: The present invention relates to ion sources (14) comprising a cathode (20) and a counter-cathode (44) that are suitable for ion implanters (10). Typically, the ion source is held under vacuum and produces ions using a plasma generated within an arc chamber (16). Plasma ions are extracted from the arc chamber and subsequently implanted in a semiconductor wafer (12). The ion source according to the present invention further comprises a cathode (40) arranged to emit electrons into the arc chamber; an electrode (44) positioned in the arc chamber such that electrons emitted by the cathode are incident thereon; one or more voltage potential sources (76) arranged to bias the electrode; and a voltage potential adjuster (82) operable to switch between the voltage potential source biasing the electrode positively thereby to act as an anode and the voltage potential source biasing the electrode negatively thereby to act as a counter-cathode.

Abstract: The invention relates to improving the efficiency of ion flow from an ion source, by reducing heat loss from the source both in the ion chamber of the ion source and its constituent parts (e.g. the electron source). This is achieved by lining the interior of the ion chamber and/or the exterior with heat reflective and/or heat insulating material and by formation of an indirectly heated cathode tube such that heat transfer along the tube and away from the ion chamber is restricted by the formation of slits in the tube. Efficiency of the ion source is further enhanced by impregnating and/or coating the front plate of the ion chamber with a material which comprises an element or compound thereof, the ions of which element are the same specie as those to be implanted into the substrate from the source thereof.

Abstract: The present invention relates to ion sources (14) comprising a cathode (20) and a counter-cathode (44) that are suitable for ion implanters (10). Typically, the ion source is held under vacuum and produces ions using a plasma generated within an arc chamber (16). Plasma ions are extracted from the arc chamber and subsequently implanted in a semiconductor wafer (12). The ion source according to the present invention further comprises a cathode (40) arranged to emit electrons into the arc chamber; an electrode (44) positioned in the arc chamber such that electrons emitted by the cathode are incident thereon; one or more voltage potential sources (76) arranged to bias the electrode; and a voltage potential adjuster (82) operable to switch between the voltage potential source biasing the electrode positively thereby to act as an anode and the voltage potential source biasing the electrode negatively thereby to act as a counter-cathode.

Abstract: The invention relates to improving the efficiency of ion flow from an ion source, by reducing heat loss from the source both in the ion chamber of the ion source and its constituent parts (e.g. the electron source). This is achieved by lining the interior of the ion chamber and/or the exterior with heat reflective and/or heat insulating material and by formation of an indirectly heated cathode tube such that heat transfer along the tube and away from the ion chamber is restricted by the formation of slits in the tube. Efficiency of the ion source is further enhanced by impregnating and/or coating the front plate of the ion chamber with a material which comprises an element or compound thereof, the ions of which element are the same specie as those to be implanted into the substrate from the source thereof.

Abstract: Provided is an ion implanter having a deceleration lens assembly comprising a plurality of electrodes in which one or more of the apertures of the deceleration electrodes are shaped in a manner which can improve performance of the ion implanter. In one embodiment, an electrode aperture is generally elliptical in shape and conforms generally to the shape of the beam passing through the aperture. In another aspect, an axis segment extends 40% of the length of the aperture from the aperture center to an intermediate point at the end of the segment. The average width of the aperture measured at each point from the center to the intermediate point is substantially less than the maximum width of the aperture.

Abstract: An ion implanter has an ion source (10) and an ion beam extraction assembly (50) for extracting the ions. The extraction assembly (50) is a tetrode structure and one of the pairs of extraction electrodes (51) has left and right ports (54, 55) located in opposite sides of the ion beam emerging from the ion source (10). The left and right electrode ports (54, 55) are electrically isolated from each other and connected to independent voltage sources (210, 230). The ion implanter also has a baffle plate (60) at the entrance to a mass analyser (90) downstream of the extraction assembly (50). The baffle plate (60) is also split into two halves (60? and 60?). By measuring the beam current incident on the two halves (60?, 60?) of the baffle (60), the relative voltages supplied to the left and right electrode parts (54, 55) may be adjusted so as to steer the ion beam and adjust the angle of incidence of the longitudinal axis thereof relative to the input of the analysing magnet (90).

Abstract: The invention relates to improving the efficiency of ion flow from an ion source, by reducing heat loss from the source both in the ion chamber of the ion source and its constituent parts (e.g. the electron source). This is achieved by lining the interior of the ion chamber and/or the exterior with heat reflective and/or heat insulating material and by formation of an indirectly heated cathode tube such that heat transfer along the tube and away from the ion chamber is restricted by the formation of slits in the tube. Efficiency of the ion source is further enhanced by impregnating and/or coating the front plate of the ion chamber with a material which comprises an element or compound thereof, the ions of which element are the same specie as those to be implanted into the substrate from the source thereof.

Abstract: G2 electrode is mounted so as to be movable along the beam line and, optionally, perpendicular to it as well. G1 and G2 are curved with a constant gap between G1 and G2 in the radial direction (so that the two electrodes are concentric). This contrasts with the prior art where G1 and G2 were equidistantly spaced along the beam line direction instead. G1 is made re-entrant adjacent the slit so as to improve extraction efficiency from the plasma. Finally, a lens such as a quadrupole lens is formed downstream of G3.

Abstract: The invention relates to improving the efficiency of ion flow from an ion source, by reducing heat loss from the source both in the ion chamber of the ion source and its constituent parts (e.g. the electron source). This is achieved by lining the interior of the ion chamber and/or the exterior with heat reflective and/or heat insulating material and by formation of an indirectly heated cathode tube such that heat transfer along the tube and away from the ion chamber is restricted by the formation of slits in the tube. Efficiency of the ion source is further enhanced by impregnating and/or coating the front plate of the ion chamber with a material which comprises an element or compound thereof, the ions of which element are the same specie as those to be implanted into the substrate from the source thereof.

Abstract: G2 electrode is mounted so as to be movable along the beam line and, optionally, perpendicular to it as well. G1 and G2 are curved with a constant gap between G1 and G2 in the radial direction (so that the two electrodes are concentric). This contrasts with the prior art where G1 and G2 were equidistantly spaced along the beam line direction instead. G1 is made re-entrant adjacent the slit so as to improve extraction efficiency from the plasma. Finally, a lens such as a quadrupole lens is formed downstream of G3.

Abstract: A post mass selection decel lens (9) is located between the exit aperture (55) of the mass selection chamber (47) and the entry (74) to the electron confinement tube (69) of the PFS. The lens comprises a first electrode (65) at the substrate potential, a second electrode (60) at the flight tube potential, and a field electrode (61) between them at a relatively high (negative) potential sufficient to provide focusing of the ion beam at the first electrode. The first electrode is larger than the beam to avoid deflecting ions at the periphery of the aperture out of the beam. The first electrode has an aperture which is smaller than that of the field electrode. The field electrode is at least -5 kV relative to the flight tube, that is substantially more than required for electron suppression. Additional apertures are provided between the process chamber and the mass selection chamber to improve evacuation.