Ion beam generator
AssigneeApplied Materials, Inc.
InventorsRichard David Goldberg, David George Armour, Christopher Burgess
Life of this patent
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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.
Claims19
An ion beam generator for an ion implantation system, the ion beam generator comprising:
- an ion source for generating ions to be implanted;
- and
- an extraction electrode assembly comprising a plurality of electrodes for extracting and accelerating ions from the ion source;
- the extraction assembly including 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 along a first ion extraction axis, and a ground electrode downstream of the extract ion electrode in the said ion extraction direction;
- wherein the source electrode and the extraction electrode each have a curved portion adjacent an electrode aperture, the curvature of each curved portion being in a first plane defined between the ion extraction axis and a second axis orthogonal thereto, the distance radially from a surface of the curved portion of the source electrodes to a surface of the curved portion of the extraction electrode being constant along at least a part of the length of each curved portion.
An ion beam generator for an ion implantation system, the ion beam generator comprising:
- an ion source for generating ions to be implanted;
- and
- an extraction electrode assembly comprising a plurality of electrodes for extracting and accelerating ions from the ion source;
- the extraction assembly including
- (a) a source electrode at the potential of the ion source;
- (b) an extraction electrode adjacent to the source electrode and at a potential different thereto, to extract ions along a first ion extraction axis;
- (c) a suppression electrode downstream of the extraction electrode along the ion extraction axis;
- and
- d) a ground electrode downstream of the suppression electrode and maintained in use at a ground potential;
- the source electrode and the extraction electrode being relatively movable in a direction generally parallel with and/or perpendicular to the said first ion extraction axis.
An ion beam generator for an ion implantation system, the ion beam generator comprising:
- an ion source for generating ions to be implanted;
- and
- an extraction electrode assembly comprising a plurality of electrodes for extracting and accelerating ions from the ion source;
- the extraction assembly including 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 along a first extraction axis, and a ground electrode downstream of the extraction electrode in the said ion extraction direction;
- wherein the ion source includes an ion source front plate having a first part relatively distant from the ion extraction axis and a second part relatively adjacent to the ion extraction axis,
- the said first part being offset from the second part along the said ion extraction axis and wherein the said first part is downstream of the said second part such that the said second part forms a re-entrant surface.
An ion beam generator for an ion implantation system, the ion beam generator comprising:
- an ion source for generating ions to be implanted;
- and
- an extraction electrode assembly comprising a plurality of electrodes for extracting and accelerating ions from the ion source;
- the extraction assembly including
- (a) a source electrode at the potential of the ion source;
- (b) an extraction electrode adjacent to the source electrode and at a potential different thereto, to extract ions along a first ion extraction axis;
- and
- (c) an electrostatic lens comprising a lens electrode and a ground electrode, the lens being arranged downstream of the extraction electrode so as to control the focussing of ions there.
An ion implanter for implanting ions into a semiconductor wafer, including the ion beam generator of any preceding claim.
Dependencies are inferred from the claim text.