US 7,598,505 B2 · Multichannel ion gun

Abstract

The present invention discloses systems and methods for generating low energy, high current ion beams by scaling beamline dimensions and employing multiple beamlines. An array of beamlets is generated by an ion source. The beamlets then pass through a mass analysis module that permits selected ions to pass while blocking other ions and/or particles. The selected ions can then be accelerated to a desired energy level. Subsequently, the beamlets are diverged in horizontal and vertical directions to form a single low energy, high current ion beam.

Drawings

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Drawings

Claims25

Dependent claims

A multi-channel ion implantation system comprising:

a beam source that generates a beamlet array;
and
a beamline assembly that comprises:
a mass analyzer module that operates on the beamlet array to remove ions having a non-selected mass energy product;
and
a beam formation component that combines the beamlet array into a single ion beam after the ions having the non-selected mass energy product have been removed from the beamlets.

3 more elements

A multi-channel ion implantation system comprising:

a beam source and triode extraction assembly that generate a beamlet array;
and
a beamline assembly comprising an array of channels through which the beamlet array passes, the beamline assembly comprising:
a first array of magnets comprised of pairs of permanent magnets defining a first magnetic field between the pairs of magnets;
first beamguide spacers positioned in between columns of the first array of magnets, wherein the first beamguide spacers comprise channels through which the beamlet array passes;
a first slit positioned downstream of the first array of magnets and having a first resolution that permits passage of ions having a selected mass energy product and substantially blocks other ions having a non-selected mass energy product;
horizontal partition plates positioned downstream of the first array of magnets and positioned between rows of magnets of the first array of magnets;
a second array of magnets positioned downstream of the vertical deflection plates and comprised of pairs of permanent magnets defining a second magnetic field between the pairs of magnets;
second beamguide spacers positioned in between columns of the second array of magnets, wherein the second beamguide spacers comprise channels through which the beamlet array passes;
a second slit positioned downstream of the second array of magnets having a second resolution that permits passage of ions having the selected mass energy product and substantially blocks other ions having a non-selected mass energy product;
vertical deflection plates positioned downstream of the second slit and in between rows of the beamlet array that cause the beamlets within the array to diverge in a vertical direction;
and
a drift region positioned downstream of the vertical deflection plates that cause the beamlets within the array to diverge in a horizontal direction and form into a single ion beam.

10 more elements

Dependencies are inferred from the claim text.

Description6,245 words

Summary645 words

#The present invention relates generally to ion implantation systems, and more particularly to low energy, high current ion implantation systems and methods.

#Ion implantation systems are used to dope semiconductors with impurities in integrated circuit manufacturing. In such systems, an ion source ionizes a desired dopant element, which is extracted from the source in the form of an ion beam of desired energy. The ion beam is then directed at the surface of a semiconductor wafer in order to implant the wafer with the dopant element. The ions of the beam penetrate the surface of the wafer to form a region of desired conductivity, such as in the fabrication of transistor devices in the wafer. A typical ion implanter includes an ion source for generating the ion beam, a beamline assembly including a mass analysis apparatus for mass resolving the ion beam using magnetic fields, and a target chamber containing the semiconductor wafer or workpiece to be implanted by the ion beam.

#In order to achieve a desired implantation for a given application, the dosage and energy of the implanted ions may be varied. The ion dosage controls the concentration of implanted ions for a given semiconductor material. Typically, high current implanters are used for high dose implants, while medium current implanters are used for lower dosage applications. The ion energy is used to control junction depth in semiconductor devices, where the energy levels of the beam ions determine the degree to which ions are implanted or the depth of the implanted ions in the workpiece.

Brief description of the drawings9 figures

#FIG. 1 is a block diagram of a multi-beamline ion implantation system in accordance with an aspect of the present invention.

#FIG. 2 is a vertical view of a multi-channel, multi-beamline ion implantation system in accordance with an aspect of the present invention.

#FIG. 3 is a perspective view of a single channel through which an individual ion beamlet passes in accordance with an aspect of the present invention.

Detailed description5,392 words

#The present invention will now be described with reference to the drawings wherein like reference numerals are used to refer to like elements throughout. The illustrations and following descriptions are exemplary in nature, and not limiting. Thus, it will be appreciated that variants of the illustrated systems and methods and other such implementations apart from those illustrated herein are deemed as falling within the scope of the present invention and the appended claims.

#Many ion implantations performed in current semiconductor or other fabrication processes are shallow and/or ultra-shallow implants that form shallow and/or ultra-shallow junction depths in formed devices. These shallow and/or ultra-shallow implants typically employ low energies (e.g., 1 keV), but require relatively high beam current (e.g., 20 to 30 milli amps). Generally, it is appreciated that high current, low energy ion beams are obtained by extracting the ion beam from an ion source at a relatively high energy. Then, the ion beam is mass analyzed/purified and transported to a position relatively close to a target wafer. Subsequently, the ion beam is decelerated to a selected low energy level and is then transported to the target wafer or workpiece.

#Conventional low energy ion implantation devices can have difficulty providing relatively high ion beam current at low energies. Problems, such as increased space charge, energy contaminants, and the like, have a negative impact on the productivity of the conventional low energy implanters. Some conventional techniques have been employed that attempt to mitigate the problems, but some fundamental limitations remain and achievable beam currents for single ion beams may not satisfy the requirements of next generation semiconductor processes.

Facts

Application

11/074,434Filed 8 Mar 2005

Published

US 2006/0219944 A15 Oct 2006

Granted

6 Oct 2009

Term ends

12 Nov 2026

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 614 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification2 codes

H01J 37/3171
For changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation: for ion implantation
H01J
Electric discharge tubes or discharge lamps

Timeline

8 Mar 2005Application filedUS 11/074,434
8 Mar 2005Assigned to Axcelis Technologies, Inc.assignment of assignor's interest
5 Oct 2006PublishedUS 2006/0219944 A1
9 May 2008Assigned to Silicon Valley Banksecurity agreement
17 Apr 2009Assigned to Sen Corporationconsent and license agreement
6 Oct 2009GrantedUS 7,598,505 B2
31 Jul 2020Assigned to Silicon Valley Bank, AS Administrative Agentsecurity interest
7 Apr 2023Assigned to Axcelis Technologies, Inc.release of security interest
12 Oct 2026TodayWithin its term
12 Nov 2026Term endsEstimated, includes 614 days of adjustment

Multichannel ion gun

Life of this patent

Multichannel ion gun

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims25

Description6,245 words

Drawings

Classification2 codes

Life of this patent

Description6,245 words