TWI576886B - Ionimplantation system,analyzer beamline operational train,and method for removing unwanted species form ion beam - Google Patents

Description

Ion implantation system, beam line operation column of the analyzer, method of removing unwanted species from the ion beam

The present invention relates generally to ion implantation systems, and more particularly to methods and apparatus for forming variable mass analysis exit orifices that are constructed to block unwanted implanted isotopes from being transferred to the workpiece.

Ion implantation is a physical process applied to the fabrication of semiconductor devices that selectively implants dopants into semiconductor substrates (eg, workpieces, wafers, etc.). Ion implantation can be performed in a variety of ways to achieve specific properties on or in the substrate. For example, the diffusivity of a dielectric layer on a substrate can be limited by implanting a particular type of ion into the substrate.

One or more ion species produced by the ion source are provided to the mass analyzer during implantation. The mass analyzer is constructed to receive one or more ions and to generate a dipole magnetic field that acts on the ion species to select a particular ion species based on the ion-to-mass ratio. Specific ionic species are passed to downstream workpieces. In a typical sequence implantation process, the resulting ion beam can be scanned across a single axis of the workpiece moving in orthogonal directions, or alternatively the workpiece can be moved along a pair of orthogonal axes relative to the stationary ion beam.

An ion implantation system is provided. The ion implantation system includes: an ion source configured to generate an ion beam including a plurality of isotopes and transmitted along the beam line The mass analyzer is constructed to generate a magnetic field that bends the individual isotope trajectories in the ion beam based on the charge-to-mass ratio of the isotope; the mass analysis variable exit aperture is constructed to insert a variable blocking structure An ion beam that avoids the isotope in the cross-sectional area of the ion beam passing down the beam line; and an analytical hole that includes a fixed-sized opening downstream of the mass analyzer, wherein the opening is positioned relative to the ion beam, such An ion that rejects a charge-to-mass ratio is not appropriate.

A beamline operation column of the analyzer is provided. The beam line operation column of the analyzer comprises: an ion source constructed to generate an ion beam comprising a plurality of isotopes and transmitted along the beam line; and a mass analyzer configured to generate a magnetic field based on the charge-to-mass ratio of the isotope Individual isotope traces in the ion beam are curved to provide heavier isotopes along the inner diameter and lighter isotopes along the outer diameter; mass analysis variable exit apertures constructed to penetrate the barrier structure into the ion beam The isotope is deflected away from the beamline, wherein the barrier structure allows one isotope species to pass down the beamline and avoids other isotope species of close mass passing down the beamline; and the analytical pores, which are located downstream of the mass analyzer A fixed size opening wherein the opening is positioned relative to the ion beam such that ions of a charge-to-mass ratio are rejected.

A method of removing unwanted ion cloth plant species isotopes from an ion beam is provided. The method includes: generating an ion beam comprising a plurality of isotopes, wherein the ion beam is transmitted along a beam line; applying a magnetic field to the ion beam to provide a heavier isotope along the inner diameter and a lighter isotope along the outer diameter; and The structure is moved into the cross-sectional area of the ion beam to reduce the size of the exit aperture of the mass analyzer. The isotope having the first mass is allowed to pass down the beam line, and other isotopes of close mass are allowed to pass down the beam line.

The invention will now be described with reference to the drawings, in which the same reference numerals are used to refer to the same elements.

As integrated semiconductor devices become more difficult to size, new integrated wafer fabrication techniques continue to evolve. One such new manufacturing technique relies more on the particular species used for planting, such as cockroaches. The source of gas for helium is germanium tetrafluoride (GeF ₄ ), which contains many isotopic species in a small range of masses. The inventors have experienced a small range of masses spanned by different helium isotopes, so that existing mass analyzers may not be able to effectively filter out unwanted isotopes (ie, the standard exit pores of the mass analyzer cannot function to avoid unwanted mass proximity). The species isotope leaves the analytical well). If such unwanted isotopes are not effectively filtered out, they may corrode the beamline members and may cause contamination of the workpiece.

Accordingly, a mass analysis variable exit aperture (MAVEA) that selectively adjusts the exit size of the mass analyzer is disclosed. By selectively adjusting the size of the exit orifice of the mass analyzer, MAVEA provides a high resolution choice across the small range of mass isotopes in the ion beam. In some embodiments, the MAVEA bit is constructed in a mass analyzer that creates a magnetic field that bends the isotope trajectory in the ion beam based on the charge-to-mass ratio of the isotope. MAVEA is constructed to selectively insert a blocking structure into the beam line to block a portion of the ion beam. Block one Part of the ion beam effectively limits the size of the exit orifice by allowing the selected implant isotope to pass while blocking the passage of unwanted isotopes of close mass.

Figure 1 illustrates an example of an ion implantation system 100 in accordance with an aspect of the present invention. The ion implantation system 100 is presented for demonstration purposes, and it will be appreciated that aspects of the invention are not limited to the ion implantation system described, but other suitable ion implantation systems may be employed.

The ion implantation system 100 has a terminal 102, a wire harness assembly 104, and an end station 106. Terminal 102 includes an ion source 108 that is powered by high voltage power supply 110. The ion source 108 is constructed to produce an implanted isotope (i.e., ion) that is extracted and formed into an ion beam 112 and then directed to the end station 106 along a beamline in the beamline assembly 104.

The beamline assembly 104 has a beam guide 114 and a mass analyzer 116. The mass analyzer 116 forms about ninety degrees in this example and includes one or more magnets (not shown) for establishing a (dipole) magnetic field therein. When the ion beam 112 enters the mass analyzer 116, the implanted isotope in the ion beam is bent by the magnetic field. Isotopes with different charge-to-mass ratios are bent to have a radius of curvature that is inversely proportional to their mass, such that the ion beam is dispersed in such a way that the same mass of isotopes are spatially together (eg, a relatively heavy isotope position in the ion beam) The outer diameter, while the lighter isotope is at the inner diameter of the ion beam). The isotope having a charge to mass ratio that is too large or too small is deflected into the sidewall 118 of the beam guide 114. In this manner, the mass analyzer 116 allows those ions of the ion beam 112 having a desired charge to mass ratio to pass through the analytical well 120, which includes the bit in mass analysis. The opening at the end of the device 116.

The mass analysis variable exit aperture (MAVEA) 122 is located along the beam line in the beamline assembly 104. The MAVEA 122 is constructed to penetrate the barrier structure into the beam line such that a portion of the ion beam 112 is blocked. By blocking a portion of the ion beam 112, unwanted isotope can be effectively removed from the beam line. In some embodiments, the MAVEA 122 position is upstream of the analytical aperture 120. In some embodiments, the MAVEA 122 is located in the mass analyzer 116 such that it is removed from the beam line by the MAVEA 122 after the unwanted isotope is dissipated by the magnetic field. For example, in some embodiments, the MAVEA 122 is mounted in the beam guide 114, which in turn is mounted between the magnetic poles of an atomic mass unit (AMU) magnet of the mass analyzer. In an alternative embodiment, the MAVEA 122 can be located at any other location in the beamline downstream of the AMU magnet.

In certain embodiments, the MAVEA 122 includes a blocking structure that is configured to penetrate the ion beam 112 from the outer diameter of the mass analyzer 116. By penetrating the ion beam 112 from the outer diameter, the MAVEA 122 can allow the lighter isotope to pass through the mass analysis aperture while blocking the heavier isotope, since the magnetic field of the mass analyzer 116 bends the lighter isotope much more than Heavy isotope (ie, an isotope with a large atomic mass). For example, mass analyzer 116 will bend a strontium isotope with an atomic mass unit of 72 more than an isotope of mass 73 or 74, such that an isotope with an atomic mass unit of 72 follows the inner radius of curvature of the ion beam. Thus, by penetrating the ion beam 112 from the outer diameter, the MAVEA 122 can be operated to allow the helium isotope of atomic mass unit 72 to exit the mass analyzer pore while simultaneously filtering out the atomic mass from the beam line. The cesium isotope at positions 73, 74, etc.

As provided herein, the MAVEA 122 is an individual structure that is separate from the downstream analysis aperture 120. For example, MAVEA 122 includes a variable blocking structure that can be moved in and out of the beamline; and parsing aperture 120 includes an isotopic structure that is fixed relative to the beamline to reject charge-to-mass ratios. The combination of MAVEA 122 and/or analytical aperture 120 and MAVEA 122 effectively forms an exit aperture of the mass analyzer that allows the isotope with the desired charge to mass ratio to exit mass analyzer 116. In one embodiment, the analytical wells 120 can be constructed to have a relatively large size to allow for a wide range of plant species, such as species used for traditional planting (eg, B, P, etc.) and for Ge, C... The MAVEA 122 is constructed to reduce the relatively large size of the analysis aperture 120. This allows the ion implantation system 100 to be used for a wide range of plant species (eg, having wide pores for B and narrow pores for Ge) with different filtration resolution requirements.

In various embodiments, ion implantation system 100 can include additional components. For example, as shown in FIG. 1, magnetic scanning system 124 located downstream of mass analyzer 116 includes a magnetic scanning element and a magnetic or electrostatic focusing element 126. Scan beam 130 then passes through a parallelizer 132 that includes two dipole magnets to change the path of scan beam 130 such that scan beam 130 travels parallel to the beam axis regardless of the scan angle. The end station 106 then receives a scanned beam 130 that is directed to the workpiece 136. The end station 106 can include a dose system 138 near the position of the workpiece to perform a calibration measurement before or during the implantation operation.

2 is a block diagram of an exemplary ion implantation system 200 showing an operation The MAVEA is revealed to block unwanted isotopes in the ion beam paradigm. The ion implantation system 200 includes an exemplary ion beam 202 that passes through a mass analyzer 204 that is positioned upstream of the workpiece 212. The mass analyzer 204 includes one or more atomic mass unit (AMU) magnets 204a, 204b that are configured to generate a magnetic field that is operated on the ion beam 202 as it passes through the mass analyzer 204. The magnetic field is operated by force on charged particles (eg, implanted isotopes) in the ion beam 202, ie, F=v×B (where F is the force, v is the velocity of the charged particles, and B is the magnetic field), The particle moving path of the ion beam is curved.

Since different implanted isotopes have different masses and different momentums for equal accelerations, such bending causes the different implanted isotopes of the ion beam 202 to be spread at an angle θ, wherein the different angles of the ion beam 202 will mainly contain different Planting isotope. In general, heavier implanted isotopes are less lightly implanted by the mass analyzer's magnetic field (ie, the atomic mass of the isotope will bend less than the atomic mass of the isotope). Thus, the location of the heavier implanted isotope will be along the outer diameter of the ion beam 202, while the position of the lighter implanted isotope will be along the inner diameter of the ion beam 202. For example, ion beam 202 at angle θ ₁ will contain the heaviest isotope of ion beam 202, the angle θ ₂ will contain an isotope that is lighter than the angle θ ₁ , and the angle θ ₃ will contain an isotope that will be lighter than the angle θ ₁ And θ ₂ .

Because the mass analyzer 204 separates the isotope from the angle θ based on mass, the mass analysis variable exit aperture 206 can insert the barrier structure into the beamline to reduce the size of the exit aperture, thereby blocking unwanted implant isotopes while allowing for superiority. The selected implanted isotopes are passed down the beam line. Figure 2 As an example, the mass analysis variable exit orifice 206 is constructed upstream of the analytical orifice 208 at the outlet of the mass analyzer 204. The mass analysis variable exit aperture 206 is constructed to block the cross-sectional area of the path of the ion beam 202 such that unwanted implanted isotopes cease to pass down the beam line while allowing the selected implanted isotopes to pass down the beam line. .

The mass analysis variable exit orifice 206 allows the outlet orifice to be reduced to a size below the resolution orifice 208 downstream of the outlet of the mass analyzer 204. Thus, the mass analysis variable exit orifice 206 provides a greater filtration resolution for the unwanted isotopes than the fixed size analytical orifice 208. For example, the mass analysis variable exit aperture 206 Naijian perform ion beam path constituting a barrier, which reduces the size of the outlet aperture into a size S ₂ (i.e., formation of an ion beam to cut). In contrast, the fixed size analysis aperture 208 has a dimension S ₁ that may be greater than the dimension S ₂ of the exit aperture provided by the mass analysis variable exit aperture 206.

MAVEA 206 can be constructed to penetrate ion beam 202 from one or more sides. For example, in one embodiment, MAVEA 206 can be constructed to block the outer diameter of ion beam 202 (ie, the "long" path of travel of the ion beam). Such an embodiment allows MAVEA 206 to substantially remove heavier isotopes in the plant species. Alternatively, the MAVEA 206 can be constructed to block the inner diameter of the ion beam 202 (i.e., the "short" path of travel of the ion beam). Such an embodiment allows MAVEA 206 to substantially remove lighter isotopes in the plant species. In another embodiment, the MAVEA 206 can be constructed to block the inner and outer diameters of the ion beam 202, thereby removing lighter and heavier isotopes in the plant species.

Therefore, by controlling the upstream mass analysis variable exit aperture 206 relative to the size of the analysis aperture 208, the mass analysis variable exit aperture 206 can be constructed Reduce the size of the exit orifice of the mass analyzer seen by the ion beam. This allows the analytical well 208 to be of a relatively large size to allow for a wide range of plant species (e.g., for conventional plant species, such as B, P); while the upstream mass analysis variable exit orifice 206 can be constructed to reduce the ion beam. The exit pore size is seen to provide a reduced pore size that can remove unwanted isotopes from a small range of atomic masses of cloth plants.

The mass analysis variable exit aperture illustrated in FIG. 3 includes a blocking structure 306 (ie, a blocking shield) that can be moved into the ion beam 302 along an unwanted ion path by a mechanical drive mechanism 304 (eg, blocking primarily containing unwanted plant species) The cross-sectional area of the ion beam 302). Mechanical drive mechanism 304 is constructed to dynamically adjust the position of barrier structure 306 in ion beam 302 in a progressive manner. For example, the mechanical drive mechanism 304 can be configured to move the blocking structure 306 into and out of the ion beam 302. In one embodiment, the mechanical drive mechanism 304 can include, for example, a linear actuator, such as a helical gear drive mechanism.

The exit aperture of the mass analyzer can be created by a combination of the blocking structure 306 and the analytical aperture 308 such that the blocking structure 306 effectively reduces the size of the analytical aperture 308 to below its nominally fixed size. For example, the mechanical drive mechanism 304 is constructed to penetrate the outer diameter of the ion beam 302 to remove unwanted species from the ion beam 302. The resulting ion beam is then provided to an analytical well 308 that further blocks a portion of the ion beam 302 while further removing unwanted species from the ion beam 302. Thus, the ion beam 302 exiting the analytical aperture 308 has been filtered by both the blocking structure 306 and the analytical aperture 308.

The barrier structure can include a wide range of shapes, sizes, materials. In an embodiment, the barrier structure may comprise a graphite based material.

4A, 4B illustrate two non-limiting embodiments of an example of a barrier shield shape that can be used for mass analysis variable exit apertures as provided herein.

In the embodiment illustrated in FIG. 4A, the blocking structure 402 can include a wedge-shaped structure having an inclined surface 404 that slopes away from the ion beam 408. The inclined surface 404 is configured to deflect the unwanted isotope 406 away from the ion beam 408. For example, as illustrated in FIG. 4A, the wedge-shaped blocking structure 402 enters the ion beam 408 from the outer diameter of the ion beam path such that the inclined surface 404 deflects the unwanted isotope 406 away from the ion beam 408.

In some additional embodiments exemplified in FIG. 4B, the blocking structure 402 can have a serrated surface 412 that is configured to deflect any unwanted isotopes 406 away from the ion beam 408 such that the unwanted isotopes 406 do not follow the beam. The line goes down. For example, as illustrated in FIG. 4B, the serrated surface 412 can be positioned on the "top" of the barrier structure 402 (ie, on the portion of the barrier structure 402 that first enters the ion beam 408).

In the embodiment illustrated in FIG. 5, mass analyzer 502 can include a beam dumper 504 that is configured to collect unwanted isotopes that are deflected away from ion beam 508 by barrier structure 506. Beam dumper 504 can include a cavity positioned to receive the isotope reflected by blocking structure 506. For example, as exemplified in FIG. 5, the position of the beam dumper 504 collects isotopes that are reflected from the wedge-shaped surface of the barrier structure 506 that forms the isotope that forms the offset. By collecting the unwanted isotopes, the beam dumper 504 ensures that the deflected, collected isotopes do not enter the beam line again.

In certain embodiments, one or more ion beam characteristics (eg, ion beam current or shape) downstream of the mass analysis variable exit aperture may be monitored. Monitored Features such as beam current or shape can then be used to determine the optimal location of the barrier structure. 6 illustrates an exemplary ion implantation system 600 that includes a mass analyzer 602 having a mass analysis variable exit aperture that includes a blocking structure 610 controlled by a control unit 606, the control unit 606 being coupled to An ion beam measuring element 604 is located downstream of the blocking structure 610.

In some embodiments, the ion beam measuring component 604 is constructed to be described by measuring one or more ion beam characteristics (eg, beam current, beam profile, beam shape, etc.) at a location downstream of the mass analyzer 602. The state of the ion beam 612. In an embodiment, the ion beam measuring component 604 can include a beam current measuring component, such as a Faraday cup. In an alternative embodiment, the ion beam measuring component 604 can include one or more contourers that can continue to traverse the contour path, thereby measuring the contour profile of the scanned beam.

The measured characteristics of ion beam 612 are then provided to control unit 606. Control unit 606 is constructed to form an analysis of the beam characteristics that perform the measurement and a selective generation control signal S _CTRL that adjusts the position of barrier structure 610 within ion beam 612. In one embodiment, control unit 606 can be configured to change the position of barrier structure 610 in ion beam 612 in response to the measured ion beam characteristics. In some embodiments, control unit 606 is constructed to compare the measured beam characteristics to a predetermined threshold. If the measured beam characteristic is greater than a predetermined threshold value, the control signal S _CTRL will move the blocking structure 610 to increase the blocked ion beam cross-sectional area. If the measured beam characteristic is less than a predetermined threshold value, the control signal S _CTRL will move the blocking structure 610 to reduce the blocked ion beam cross-sectional area.

In some embodiments, control signal S _{CTRL is} provided to mechanical drive mechanism 608. The mechanical drive mechanism 608 is constructed to progressively increase the position of the blocking structure 610 by moving the blocking structure 610 into and out of the ion beam 612 in a progressive manner to gradually increase (eg, by blocking fewer ion paths) or to gradually decrease (eg, The beam current is blocked by blocking more ion paths to achieve the desired beam current (eg, based on a predetermined threshold). The blocking structure 610 can be determined by observing the previously stabilized beam current while slowly moving the blocking structure 610 into the ion beam path until an unacceptable decrease in beam current is seen (eg, until the ion beam current violates a predetermined threshold). The final location. The blocking structure 610 can then be pulled slightly until an acceptable minimum beam current is again obtained.

Figures 7A-7D illustrate a more specific embodiment of a mass analysis variable exit orifice that is variably controlled by a control system coupled to a downstream beam current measuring device. Figures 7A-7C illustrate mass analysis exit hole blocking structures at different locations in the mass analyzer beam path. The graph exemplified in Figure 7D shows the beam current (y-axis) as a function of time (x-axis) and the percent blocking of the ion beam (y-axis) as a function of time (x-axis).

Referring to Figure 7A, at a first time t = t _1, the barrier structure 700 is out of the ion beam 702. Referring to Figure 7D, at time t _1, the percentage blocking of the ion beam to zero (graph 704), and the ion beam current in the beam current constant C ₁ (706 pattern).

Referring to Figure 7B, at a second time t = t _2, the position of the blocking structure 700 blocks a portion where the ion beam 702. Referring to Figure 7D, at time t _2, the percentage blocking of the ion beam increases starting from t ₁ (pattern 704), and the ion beam current from the beam current constant decrease from C ₁ (706 pattern).

Referring to Figure 7C, at a third time t = t _3, the position of the blocking structure 700 blocks a portion where the ion beam 702. Referring to Figure 7D, at time t _3, the percentage blocking of the ion beam increases starting from t ₂ (704 pattern), and the ion beam current from a constant beam current is further reduced from C ₁ (706 pattern).

The percentage of blocking of the ion beam can be reduced until the measured ion beam current violates a predetermined threshold value _VTH . For example, as shown in FIG. 7D, at time t _4, the ion beam current (graph 706) fall below a predetermined threshold V _TH. When the ion beam current violates a predetermined threshold value _VTH , the blocking percentage of the ion beam is increased to allow for a larger beam current that does not violate the predetermined threshold value _VTH .

FIG. 8 illustrates an embodiment of an exemplary method 800 for reducing unwanted ion cloth plant species isotopes from ion beam lines. The method 800 gradually changes the size of the exit aperture to block a portion of the ion beam while avoiding the selection of unwanted isotopic species from the mass analyzer.

Although the methods provided herein (eg, methods 800 and 900) are exemplified and described as a series of acts or events, the order of such exemplary acts or events is not to be construed in a limiting sense. For example, some acts may occur in an order different than that illustrated and/or described herein and/or concurrent with other acts or events. In addition, all of the exemplary acts may be performed to implement one or more aspects or embodiments of the present disclosure. Also, one or more of the acts shown herein can be performed in one or more separate acts and/or stages.

At 802, an ion beam is generated. The ion beam includes a plurality of isotopes having a range of atomic masses. For example, the ion beam can include a mass range at Strontium isotope of 72-74 atomic mass units. The ion beam is constructed to pass along the beam line.

At 804, a magnetic field is applied to the ion beam. The magnetic field bends the trajectory of the charged isotope in the ion beam, and the way it is bent is inversely proportional to the mass of the isotope. In some embodiments, the magnetic field can include a dipole magnetic field generated by a mass analyzer that is configured to bend different isotopes of different masses at different angles. This causes the ion beam to be dispersed at an angle where the different cross-sectional areas of the ion beam primarily comprise different implanted isotopes.

At 806, the mass analysis variable outlet aperture is adjusted in size. The mass analysis variable exit orifice can be sized to block a portion of the ion beam to prevent the selected isotopic species from leaving the mass analyzer unit. In one embodiment, the mass analysis variable exit aperture can be operated in conjunction with the analytical aperture to dynamically adjust the exit aperture size of the mass analyzer. In one embodiment, the mass analysis variable exit aperture can be adjusted over and over again.

Figure 9 illustrates a more detailed embodiment of an exemplary method 900 of reducing unwanted ion plant species isotopes from an ion beam.

At 902, an ion beam comprising a plurality of isotopes is generated. In one embodiment, to generate a charged isotope, free electrons in the dopant material gas to be ionized may be excited. It will be appreciated that any number of suitable mechanisms can be used to excite free electrons, such as, for example, RF or microwave excitation sources, electron beam emission sources, electromagnetic sources, and/or cathodes that generate arcing in the chamber. The excited electrons strike the dopant gas molecules and produce charged isotopes. Typically, positively charged isotopes are produced, although the disclosure is also applicable to systems that produce negatively charged isotopes.

At 904, a magnetic field is applied to the ion beam. The magnetic field bends the isotope in the ion beam by applying a magnetic force to the charged particles in the ion beam. The magnetic force bends the trajectory of the isotope as a function of the mass of the isotope, with smaller isotopes bent more than the larger mass of isotopes.

At 906, the blocking structure is moved into the cross-sectional area of the ion beam. Because isotopes of different masses are generally dispersed by magnetic force at the beam path angle, blocking a portion of the ion beam will greatly reduce unwanted isotopes while minimizing the effects on the desired isotopic species. For example, extending the barrier structure to the outer edge of the ion beam greatly reduces the number of heavy isotopes (i.e., isotopic species that are heavier than the desired isotope) while minimizing the desired isotope.

At 908, one or more features of the ion beam are measured. In some embodiments, one or more features can include a beam current of the ion beam. In one embodiment, the ion beam current can be measured by a Faraday cup. In certain embodiments, one or more features of the ion beam are measured downstream of the barrier structure.

At 910, the measured beam characteristics are compared to a predetermined threshold value. If the measured beam characteristics do not violate (eg, equal) a predetermined threshold value, then the blocking structure is not moved and the method ends.

However, if the measured beam characteristic violates (eg, does not equal) a predetermined threshold value, the blocking structure is moved. In particular, if the measured beam characteristic is less than a predetermined threshold value, the blocking structure is moved into a position that blocks a larger cross-sectional area (912). If the measured beam characteristic is greater than a predetermined threshold value, the blocking structure is moved into a position that blocks a smaller cross-sectional area (eg, less than the previous cross-sectional area) (914).

One or more beam features (eg, current density, profile distribution) are then measured again at 908, and steps 910-914 can be repeated until a barrier is reached The optimal position of the structure (i.e., until the measured beam characteristic is equal to the predetermined threshold value).

While the invention has been shown and described with reference to the specific embodiments of the embodiments In particular, with regard to the various functions performed by the above-described components (components, devices, circuits, systems, etc.), the terms used to describe such components (including the "institution" of the reference) are corresponding to execution unless otherwise stated. Any of the components of the particular function of the component (i.e., functionally equivalent) perform the functions of the exemplary embodiments of the invention herein, even if not structurally equivalent to the disclosed structure. In this regard, it will also be appreciated that the present invention includes computer readable media having computer executable instructions for performing the steps of the various methods of the present invention. Moreover, although a particular feature of the invention may have been disclosed with respect to only one of several implementations, such features may be implemented in any other combination as desired or advantageous for any given or particular use. One or more other features. Furthermore, to the extent that the words "including", "including", "having" and variations thereof are used in the "embodiment" or the scope of the patent application, these words are intended to be in a manner similar to "contains". Covered.

100‧‧‧Ion implantation system

102‧‧‧ Terminal

104‧‧‧Bundle assembly

106‧‧‧End station

108‧‧‧Ion source

110‧‧‧High voltage power supply

112‧‧‧Ion beam

114‧‧‧beam guide

116‧‧‧Quality Analyzer

118‧‧‧ side wall

120‧‧‧analysis hole

122‧‧‧Quality Analysis Variable Exit Hole (MAVEA)

124‧‧‧Magnetic scanning system

126‧‧‧Magnetic or electrostatic focusing elements

128‧‧‧Magnetic scanning elements

130‧‧‧Scanning beam

134‧‧ ‧ parallelizer

136‧‧‧Workpiece

138‧‧‧Dose system

200‧‧‧Ion implantation system

202‧‧‧Ion Beam

204‧‧‧Quality Analyzer

204a, 204b‧‧‧Atomic mass unit (AMU) magnet

206‧‧‧Quality analysis variable exit hole

208‧‧‧analysis hole

210‧‧‧Ion beam

212‧‧‧Workpiece

300‧‧‧Ion implantation system

302‧‧‧Ion Beam

304‧‧‧Mechanical drive mechanism

306‧‧‧Block structure

308‧‧‧analysis hole

310‧‧‧Quality Analyzer

400‧‧‧Quality Analysis Variable Exit Hole

402‧‧‧Block structure

404‧‧‧Sloping surface

406‧‧‧Don't isotope

408‧‧‧Ion Beam

410‧‧‧Quality Analysis Variable Exit Hole

412‧‧‧Sawtooth surface

500‧‧‧Quality Analysis Variable Exit Hole

502‧‧‧Quality Analyzer

504‧‧‧beam dumper

506‧‧‧Block structure

600‧‧‧Ion implantation system

602‧‧‧Quality Analyzer

604‧‧‧Ion beam measuring element

606‧‧‧Control unit

608‧‧‧Mechanical drive mechanism

610‧‧‧Block structure

612‧‧‧Ion Beam

700‧‧‧Block structure

702‧‧‧Ion Beam

704‧‧‧ graphics

706‧‧‧ graphics

800‧‧‧ method

900‧‧‧ method

1 is a block diagram of an exemplary ion implantation system; FIG. 2 illustrates an ion beam paradigm that passes through a mass analyzer having a mass analysis variable exit aperture; FIG. 3 illustrates an exemplary ion beam paradigm with a mass analysis variable exit a mass analyzer of the aperture, the exit aperture comprising a barrier structure; Figures 4A, 4B illustrate two non-limiting embodiments of an example of a barrier structure that can be used for mass analysis variable exit apertures; Figure 5 illustrates an exemplary mass analysis exit aperture A block diagram of a particular embodiment constructed to redirect unwanted isotope to a beam dumper; FIG. 6 illustrates an ion implantation system including a mass analyzer having a mass analysis variable exit orifice coupled to a downstream ion The control system of the beam monitoring system is controlled; Figures 7A-7C demonstrate the mass analysis exit hole blocking structure at different locations in the ion beam; the graph of Figure 7D shows the beam current and blocking percentage of the ion beam path as a function of time; 8 Demonstrates certain embodiments of a method of reducing unwanted ion plant species isotopes from ion beam lines; and Figure 9 illustrates some more detailed embodiments of methods for reducing unwanted plant species from ion beam lines.

200‧‧‧Ion implantation system

202‧‧‧Ion Beam

204‧‧‧Quality Analyzer

204a‧‧‧Atomic mass unit magnet

204b‧‧‧Atomic mass unit magnet

206‧‧‧Quality analysis variable exit hole

208‧‧‧analysis hole

210‧‧‧Ion beam

212‧‧‧Workpiece

Claims (19)

An ion implantation system comprising: an ion source constructed to generate an ion beam comprising a plurality of isotopes and transmitted along a beam line; a mass analyzer configured to generate a magnetic field based on a charge-to-mass ratio of the isotope The individual isotope trajectories in the ion beam are curved; the mass analysis variable exit aperture is constructed to insert a variable blocking structure into the ion beam for varying the size of the variable exit aperture to avoid isotope along the ion beam cross-sectional area The beam line is passed down; and the analytical hole is an individual structure separate from the mass analysis variable exit hole and includes a fixed size opening downstream of the mass analyzer, wherein the mass analysis variable exit hole is in the analytical hole Upstream, and wherein the opening is positioned relative to the ion beam, such that the ions of the charge-to-mass ratio are rejected. For example, in the ion implantation system of claim 1, wherein the mass analysis variable outlet hole is located in the mass analyzer. The ion implantation system of claim 1, wherein the variable barrier structure comprises a wedge-shaped structure configured to deflect an isotope having a selected charge-to-mass ratio away from the beam line. The ion implantation system of claim 3, further comprising: a beam dumper configured to collect the isotope that is deflected away from the beam line by the variable barrier structure, thereby preventing the collected isotope from entering the beam line again. The ion implantation system of claim 1, wherein the variable barrier structure comprises a serrated surface configured to deflect an isotope having a selected charge to mass ratio away from the beam line. An ion implantation system according to claim 1, wherein the magnetic field bends the trajectory of the individual isotope such that the heavier isotope position is along the inner diameter of the ion beam and the lighter isotopic position is along the outer diameter of the ion beam; The variable barrier structure is constructed to enter the ion beam from the outer diameter to block heavier isotopes, or to enter the ion beam from the inner diameter to block the lighter isotope without blocking the selected implant isotope to be supplied to the workpiece. . The ion implantation system of claim 1, further comprising: a mechanical drive mechanism configured to dynamically adjust the position of the variable barrier structure in the ion beam. An ion implantation system according to claim 7 wherein the mechanical drive mechanism comprises a linear actuator. The ion implantation system of claim 1, further comprising: an ion beam monitoring system located downstream of the mass analysis variable exit aperture and configured to measure one or more characteristics of the ion beam; and control A unit constructed to receive one or more measurement features of the ion beam and based thereon to generate a control signal, wherein the control signal operates a positional adjustment of the variable blocking structure in the ion beam cross-sectional area. Such as the ion implantation system of claim 9 of the patent scope, wherein the ion The beam monitoring system includes an ion beam measuring element constructed to describe the state of the ion beam. A beamline operation train of an analyzer, comprising: an ion source configured to generate an ion beam comprising a plurality of isotopes and transmitted along a beam line; and a mass analyzer configured to generate a magnetic field based on the charge-pair mass of the isotope The individual isotope trajectories in the ion beam are curved to provide a heavier isotope along the inner diameter and a lighter isotope along the outer diameter; the mass analysis variable exit aperture is constructed to variably penetrate the blocking structure An ion beam for varying the size of the variable exit aperture, wherein the barrier structure allows an isotope species to pass down the beam line and avoids other isotope species of close mass passing down the beam line; and an analytical hole, An individual structure separate from the mass analysis variable exit aperture and including a fixed size opening downstream of the mass analyzer, wherein the mass analysis variable exit aperture is upstream of the analytical aperture, and wherein the opening is relative to the ion beam The positioning, in this way, rejects ions whose charge is not appropriate for the mass ratio. The beamline operation column of claim 11, further comprising: a beam dumper configured to collect the isotope that is deflected away from the beamline by the barrier structure, thereby preventing the collected isotope from entering the beamline again. The beam line operation column of claim 11, wherein the barrier structure comprises a wedge structure, the structure of which will have a selected charge-to-mass ratio The isotope is deflected away from the beam line. The beamline operation column of claim 11, further comprising: an ion beam monitoring system located downstream of the mass analysis variable exit aperture and configured to measure one or more characteristics of the ion beam; and control A unit constructed to receive one or more measurement features of the ion beam and based thereon to generate a control signal, wherein the control signal operates to positionally adjust the position of the blocking structure in the ion beam. A method of removing unwanted ion cloth plant species isotopes from an ion beam, comprising: generating an ion beam comprising a plurality of isotopes, wherein the ion beam is transmitted along a beam line; applying a magnetic field to the ion beam to provide a comparison along the inner diameter Heavy isotope and lighter isotope along the outer diameter; and moving the barrier structure into the cross-sectional area of the ion beam to reduce the exit pore size of the mass analyzer, while allowing the isotope with the first mass to pass down the beam line and block Other isotopes of similar mass are passed down the beam line. The method of claim 15 wherein the barrier structure is constructed to enter the ion beam from the outer diameter such that it blocks an isotope that is heavier or less light than the selected implanted isotope. The method of claim 15, wherein the barrier structure comprises a wedge-shaped structure configured to deflect the isotope having the selected charge-to-mass ratio away from the beamline. For example, the method of claim 17 further includes: Collect the isotope that is deflected away from the beamline by the barrier structure to prevent ions from entering the beamline again. The method of claim 15, further comprising: measuring an ion beam current of the ion beam at a downstream location of the barrier structure; and comparing the measured ion beam current to a predetermined threshold value, wherein the blocking structure can be further moved into the ion beam, Until the measured ion beam current violates a predetermined threshold.