Applied Materials, Inc.

David George Armour

Richard David Goldberg

Adrian John Murrell

Christopher Burgess

Stephen Moffatt

Jonathan Gerald England

Simon Herbert Povall

Andrew Holmes

Christopher J S Burgess

Erik J H Collart

Neil Bryan

Johnathan G England

Drew Arnold

Majeed Foad

Amir Hamed Al-Bayati

Bernard F Harrison

Andrew S Devaney

Paul A Burfield

David Richard Burgin

Chris James Burgess

David Kirkwood

Jaap Van Den Berg

Andrew James Timothy Holmes

Jakob A Van Den Berg

Jakob A Van Der Berg

Erik Jan Hilda Collart

The present invention relates to ion sources () comprising a cathode () and a counter-cathode () that are suitable for ion implanters (). Typically, the ion source is held under vacuum and produces ions using a plasma generated within an arc chamber (). Plasma ions are extracted from the arc chamber and subsequently implanted in a semiconductor wafer (). The ion source according to the present invention further comprises a cathode () arranged to emit electrons into the arc chamber; an electrode () positioned in the arc chamber such that electrons emitted by the cathode are incident thereon; one or more voltage potential sources () arranged to bias the electrode; and a voltage potential adjuster () 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.

Cathode and counter-cathode arrangement in an ion source

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.

Ion sources for ion implantation apparatus

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.

Ion implanter electrodes

An ion implanter has an ion source () and an ion beam extraction assembly () for extracting the ions. The extraction assembly () is a tetrode structure and one of the pairs of extraction electrodes () has left and right ports () located in opposite sides of the ion beam emerging from the ion source (). The left and right electrode ports () are electrically isolated from each other and connected to independent voltage sources (). The ion implanter also has a baffle plate () at the entrance to a mass analyser () downstream of the extraction assembly (). The baffle plate () is also split into two halves (' and&#x2033;). By measuring the beam current incident on the two halves (&#x2033;) of the baffle (), the relative voltages supplied to the left and right electrode parts () 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 ().

Apparatus and method for monitoring and tuning an ion beam in ion implantation apparatus

G electrode is mounted so as to be movable along the beam line and, optionally, perpendicular to it as well. G and G are curved with a constant gap between G and G in the radial direction (so that the two electrodes are concentric). This contrasts with the prior art where G and G were equidistantly spaced along the beam line direction instead. G 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 G

Ion beam generator

An ion beam generation apparatus comprising an ion source ( ) for generating ions, and a tetrode extraction assembly ( ) comprising four electrodes for extracting and accelerating ions from the ion source. The extraction assembly comprises a source electrode ( ) at the potential of the ion source, an extraction electrode ( ) adjacent to the source electrode to extract ions from the ion source ( ), a ground electrode ( ), and a suppression electrode ( ) between the extraction electrode and the ground electrode. Each electrode has an aperture to allow the ion beam to pass therethrough. The gap between the extraction ( ) and suppression ( ) electrodes is variable in the direction of ion beam travel.

Ion beam generation apparatus

A source of thermionic electrons is provided inside the flight tube of a magnet, especially an analysing magnet, and extends along the beam flight path. This allows space charge to be neutralised along the beam's axis in spite of severely restricted electron mobility in this direction owing to the presence of substantially transverse magnetic field. Thermionically emitted electrons may contribute directly to the neutralisation of space charge in positive ion beams, or, in the case of negative ion beams, indirectly by ionizing residual or deliberately introduced neutral gas atoms or molecules. Examples are described and claimed in which the source is arranged outside the nominal beam envelope in the flight tube, but linked to the beam by magnetic flux generated in the flight tube. This reduces erosion of the source by the beam and so reduces beam contamination. In these examples, an important feature is the provision of electron repellers to reflect electrons back and forth across the beam. Alternative arrangements are described and claimed in which the source is positioned inside the beam. The thermionic electron source may comprise an array of filaments, and preferably is negatively biased with respect to the flight tube. Adjustment of this bias enables the energy of emitted electrons to be controlled.

Ion beam apparatus and a method for neutralizing space charge in an ion beam

Ion implanter with post mass selection deceleration

An ion implanter for implanting ions into a semiconductor wafer comprises means for generating an ion beam, means for receiving charged particles ejected from the ion beam, first means for rejecting those of the received charged particles below a first predetermined energy, second means for rejecting those of the received charged particles above a second predetermined energy, the first predetermined energy being lower than the second predetermined energy. The ion implanter further comprises means to count the number of received charged particles between the first and second predetermined energies, and scanning means for scanning the first and second predetermined energies to determine the energy at which the number of received charged particles between the first and second predetermined energies is a maximum.

Spectrum analyzer in an ion implanter

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Turton, United Kingdom

David George Armour