Patent Description:
Charged particle systems, such as (multi) electron beam systems, are being developed for high throughput maskless lithography systems, (multi) electron beam microscopy and (multi) electron beam induced deposition devices. In particular for maskless lithography systems, individual beam modulation or manipulation is needed during the writing of a pattern on a substrate.

Those lithography systems comprise either continuous sources or sources operating at constant frequency or at a varying frequency. Pattern data can be sent towards a manipulator device (or modulation means), which may be able to completely or partly stop the emitted beams from reaching the target exposure surface when necessary. The manipulator device (or modulation means) can also be provided for changing other characteristics of the emitted beam, such as a position, a cross-section, an intensity, a direction and/or an opening angle of the beam.

Preferably, the maskless lithography system comprises one source which can emit a diverging beam of charged particles, which charged particle beam is directed to an aperture array. The aperture array splits the charged particle beam into a plurality of charged particle beams or beamlets. This method of producing a plurality of charged particles has the advantage that it yields a large number of closely spaced beams or beamlets.

However, any manipulator device for such closely spaced plurality of charged particle beamlets requires closely spaced arrays of manipulators. Such closely spaced arrays are difficult to produce. In particular electrical circuits for controlling many manipulators are difficult to arrange in the lithography system. In addition, cross-talk between manipulators and other circuits in the vicinity of the manipulators can cause errors in the manipulation of the beams.

Furthermore, it can be difficult to produce a manipulator device that is able to manipulate the charged particle beam with sufficient accuracy. The manipulation by a manipulation device can depends on the exact location of the projection of the beam on the manipulation device. Any misalignment of the charged particle beam will then result in large manipulation errors.

<CIT> filed by Fujitsu Ltd discloses a thin electrostatic deflector and a scanning charged particle beam device featuring a plurality of electrodes arranged around a through opening for the particle beam.

<CIT> filed by Advantest Corp discloses particle beam deflectors in a stack of substrates for deflecting charged particle beams. The deflectors featuring multiple electrodes around respective through holes through the stack.

<CIT> discloses a single electron beam exposure system comprising a deflector formed as a sleeve and featuring a plurality of separate electrodes arranged to be separated from each other and circumferentially around the sleeve.

It is an object of the present invention to provide a solution, at least in part, for at least one of the above identified problems.

According to a first aspect, the object of the invention is achieved by providing a manipulator device for manipulation of one or more charged particle beams, wherein the manipulator device comprises:.

wherein each set of electrodes is provided with pluralities of resistors, each plurality of resistors being arranged as a voltage divider and provided in the planar substrate, wherein the resistances of each plurality of resistors are for providing voltages to the corresponding set of electrodes, such that the voltage of a particular electrode in each of the sets of electrodes is a function of the sine of the angular position of the particular electrode around the respective through opening.

Charge particle beams can be manipulated (or deflected) by applying an electric field over a through opening, through which the beams pass. The characteristics of the electric field (e.g. strength and form) define, at least partly, the manipulation or deflection of the beam(s). An electric field can be created by applying a voltage over two electrodes that are arranged around the through opening. In that case, the strength and form of the electrical field will depend on the distance between those electrodes. Dividing each of said two electrodes in a set of multiple electrodes and providing voltage differences to the pairs of a first electrode and a second electrode in dependence of positions of the respective electrodes along the perimeter of the through opening allows adjustment of the electric field in the through opening. By providing a suitable voltage distribution, the electrical field can be optimized, for example to obtain a more homogeneous electric field in said through opening.

The first set of first multiple electrodes and the second set of second multiple electrodes may each consist of two electrodes or more, preferably of 2n electrodes, n being a natural number. The electrodes may be provided partly in and/or on the planar substrate.

Manipulator devices that are known in the art comprise two electrodes arranged on opposite sides of an opening. It has been found that the electrical field generated by such manipulator devices is not sufficiently homogeneous to manipulate the charged particle beam with sufficient accuracy. Because of the lack of homogeneity of the electrical field inside the opening, the manipulation of the charged particle beams or beamlets is dependent on the location where the beam is projected in the opening.

Because of this, beams are usually projected in a small centre part of the electrical field, where the electrical field is more or less homogeneous. However, this requires a relatively large through opening for a beam and only the centre part of the through opening is used for passing a beam there through. Evidently the manipulators that are known in the art use a small fill factor; that is the ratio between the cross-section area of the beam and the area of the through opening.

Since the manipulation device according to the invention provides a much more homogeneous field inside the through opening, the manipulation device is able to manipulate the beam with a higher accuracy than manipulator devices known in the art. Furthermore, the fill factor of the manipulator device according to the invention can be much higher than in manipulator devices known in the art. Due to the larger fill factor of the manipulators of the invention, the through openings for manipulating the beams can be much smaller than in the prior art. On the one hand, this can provide additional space between the through openings for arranging control circuitry. On the other hand, the through openings can be arranged much closer to each other for providing a larger beam density in a charged particle system according to an embodiment of the invention.

In an arrangement of charged particle system, the electronic control circuit is arranged for providing said voltage differences to said pairs in dependence of a distance between a first electrode and a second electrode of the respective pair. Preferably said voltage differences are directly proportional to said distance.

Since an electrical field generated by two electrodes is dependent on (or in particular, direct proportional to) the distance between the two electrodes, the homogeneity of the electrical field in the through opening may be improved by providing voltage difference in dependence of the distance between the first electrode and the second electrode.

In an arrangement of the charged particle system, a plane is defined between the first part of the perimeter and the second part of the perimeter, a line is defined between an electrode and a diametrically opposite other electrode and an angle alpha (α) is defined by said plane and line, wherein the electronic control circuit is arranged for providing voltage differences to said electrode and said other electrode in dependence of the angle alpha (α). Preferably said voltage differences are directly proportional to sin (α).

In an arrangement of the charged particle system, a plane is defined between the first part of the perimeter and the second part of the perimeter, a line is defined between a respective electrode and a centre of the though opening, and an angle beta (β) is defined by said plane and said line, wherein the electronic control circuit is arranged for providing voltages to respective electrodes in dependence of the angle beta (β). Preferably said voltages are directly proportional to sin (β).

The electrical field lines of the electrical field, generated by the electrodes, may be perpendicular to said plane. The strength of the electrical field may depend on the voltage applied to the respective electrodes and a distance of a respective electrode to said plane. Since both sin (α) and sin (β) are each a measure for the distance of a respective electrode to said plane, providing voltage (differences) in dependence of the angle alpha (α) or the angle (β) may enable providing a homogeneous electrical field.

In this document, a plane defined between the first part of the perimeter and the second part of the perimeter may be a plane defined centrally between the first part of the perimeter and the second part of the perimeter. The plane may comprise the central axis of the through opening.

In an arrangement of the charged particle system according to the invention, the electrodes are arranged substantially symmetrically with respect to said plane and/or the electrodes are uniformly distributed along said perimeter. Providing the electrodes symmetrically or/and uniformly distributed may increase the homogeneity of the electrical field across the through opening.

In an arrangement of the charged particle system, a plane is defined between the first part of the perimeter and the second part of the perimeter and the first electrode of said pair is located opposite to the second electrode of said pair with respect to the plane. In this case, the electrical field lines of the electrical field generated by the electrodes are at least substantially perpendicular to said plane.

In an arrangement of the charged particle system according to the invention, the electronic control circuit is arranged for providing a positive voltage V to the first electrode and a negative voltage -V to the second electrode. In an embodiment of the manipulator according to the invention, the electronic control circuit is arranged for providing a positive voltage V to two electrodes from the first set and preferably a negative voltage -V to two electrodes from the second set.

An advantage of providing multiple electrodes with the same voltage V or with the polarity inverted voltage -V is that this would require a relatively simple electronic control circuit.

In an arrangement of the charged particle system according to the invention, the manipulator device further comprises two electrodes arranged along the perimeter of the through opening and substantially on said plane, wherein the electronic control circuit is arranged for providing one voltage to each of said two electrodes, said one voltage preferably being an offset voltage and preferably being substantially equal to <NUM> Volt.

Since the electrical field lines of the homogeneous electrical field generated by the electrodes should be perpendicular to the plane, these two electrodes should be provided with the same voltage, such that the voltage difference between these two electrodes is <NUM> Volt. Providing these two electrodes with an (off-set) voltage of <NUM> volt (or grounding them) would require a relatively simple circuit. However, these two electrodes may also be provided with any other offset voltage, for example - <NUM> kV. In both cases, the other electrodes may be provided with a voltage relative to this off-set voltage, for example with a positive voltage V and/or a negative voltage -V with respect to the offset voltage.

In an arrangement of the charged particle system, the electronic control circuit comprises resistors arranged as a voltage divider for providing voltages to respective electrodes, preferably as a feedback resistor of an operational amplifier. Preferably each of said first and/or second set of electrodes receives a maximum voltage, wherein said maximum voltage is then divided by said voltage divider for providing each electrode in a set of electrodes with a part of the maximum voltage. Preferably said voltage divider is arranged for providing each electrode in a set of electrodes with a part of the maximum voltage, so that said voltages are proportional with the distance between a respective electrode and the above-mentioned plane.

In an arrangement said voltage divider comprises a set of resistors, which are preferably arranged around said through opening. A voltage divider is a relatively simple circuit for providing a number of different voltages on the basis of one particular maximum voltage. In a further embodiment, the voltage divider may comprise resistors with the same resistance. This would further increase the simplicity of the circuit.

An advantage of such a simple circuit is that it can be easily made, for example with lithography technologies. It may be integrated with other circuits in or on the planar substrate. The electronic control circuit may be at least partly arranged near to or in the vicinity of the through openings.

In an arrangement of the charged particle system, the electronic control circuit comprises a first operational amplifier with a voltage divider as a feedback resistor for providing voltages to the first electrodes, and a second operational amplifier with a voltage divider as a feedback resistor for providing voltages to the second electrodes.

In an arrangement of the charged particle system, the electronic control circuit further comprises a digital-to-analogue converter for outputting a single control signal to the first and the second operational amplifier and a polarity inverter arranged for inverting a polarity of said control signal, wherein the first operational amplifier is directly connected to the digital-to-analogue converter to receive said control signal and the second operational amplifier is connected to the digital-to-analogue converter via said polarity inverter to receive an inverted control signal.

An advantage of this arrangement is the relatively simple circuit: only a single digital-to-analogue-converter is required that outputs a single control signal to the first operational amplifier. The same control signal is provided to the second operational amplifier after inversion of the polarity of the signal by the polarity inverter.

In another arrangement, the electronic control circuit comprises two digital-to-analogue-converters for outputting two control signals to the first and the second operational amplifier respectively.

In an arrangement of charged particle system, gaps are provided between adjacent electrodes. The perimeter of said through opening consists of a first area covered by the electrodes and a second area covered by the gaps, and an electrode-to-gap ratio is defined by said first area divided by said second area. In an arrangement said electrode-to-gap ratio is in the range of <NUM>-<NUM>, or preferably substantially <NUM>.

When adjacent electrodes are provided closer to each other, the generated electrical field could be more homogeneous. However, this is also more difficult to produce. It appears that with an electrode-to-gap ratio being in the range of <NUM>-<NUM>, or preferably substantially <NUM>, the two effects are optimally balanced.

In an arrangement of the charged particle system, the manipulator comprises a cross-talk shield, the cross-talk shield comprising a planar shield substrate comprising at least one through opening in the plane of the planar shield substrate, wherein the at least one through opening of the planer shield substrate is arranged in alignment with the at least one through opening of the planar substrate. An advantage of a cross-talk shield is that it prevents to some extend cross-talk between electrodes of the same through opening, between electrodes of different through openings and/or between an electrode and other circuitry present in the vicinity of the electrode.

In an arrangement of the charged particle system, a distance between the planar substrate and the planar shield substrate is smaller than <NUM> micrometer, preferably smaller than <NUM> micrometer and more preferably about <NUM> micrometer. In an arrangement of the manipulator according to the invention, a thickness of the shield planar substrate is about a diameter of the at least one through opening of the planar substrate.

In an arrangement of the charged particle system, the charged particle system further comprises:.

wherein the system is arranged for providing a voltage difference between the first planar lens substrate and the planar substrate of the manipulator device and between the planar substrate of the manipulator device and the second planar lens substrate for generating an Einzel lens for said beams.

In this arrangement, the manipulator device forms a part of an Einzel lens, comprising the first and second planar lens substrate and the planar substrate of the manipulator device in between. This Einzel lens may be arranged for focusing or projecting the charged particle beam.

In this way, the manipulator device may be integrated in the Einzel lens and this combined device may require less space in the charged particle system than providing a separate manipulator device and a separate Einzel lens.

And because of the compactness of the combined device, the effects of angular alignment errors may be limited.

The terms "above" and "below" in this document are defined with respect to the direction of a charged particle beam which passes through a though opening. The beam may travel or be directed from an upper part of the charged particle system to a lower part of the charged particle system.

In an arrangement of the charged particle system, the charged particle system further comprises a planar current limiter substrate, comprising at least one current limiter aperture, wherein the current limiter planar substrate is arranged above the planar substrate of the manipulator device and the at least one current limiter aperture is arranged in alignment with the at least one through opening of the planar substrate of the manipulator device.

An advantage of providing a current limiter is that it may enhance the homogeneity of the beams. The beam intensity of a beam may be more homogeneous in the centre of the beam than in the radial outer parts of the beam. The cross-sectional area of the beams projected on the current limiter can be arranged to be larger than the area of the respective current limiter aperture. In this case, the outer charged particles (for example electrons) of the beam will be absorbed by the current limiter and the overall homogeneity of the remaining beam will be improved.

In an arrangement of the charged particle system, the at least one current limiter aperture is smaller than the at least one through opening of the planar substrate of the manipulator device.

In an arrangement, a cross- sectional area of the at least one through opening of the planar substrate of the manipulator device is in the range of <NUM>%-<NUM>% or preferably in the range of <NUM>-<NUM>% of a cross-sectional area of the at least one current limiter aperture.

In this way, the cross-section of the beam passing through the though opening may be significantly smaller than the through opening itself. This would reduce the number of charged particles (for example electrodes) that hit or contact the planar substrate of the manipulator device. And this would reduce the damage these charged particles may cause to the electronic control circuit provided at least partly on or in the planar substrate of the manipulator device.

In an arrangement of the charged particle system,.

wherein the system is arranged for providing a voltage difference between the first planar lens substrate and the second planar substrate of the first manipulator device and between the planar substrate of the second manipulator device and the second planar lens substrate for generating an Einzel lens for said beams. In this arrangement, the two manipulator devices form a part of an Einzel lens, comprising the first and second planar lens substrate and the planar substrates of the two manipulator device in between.

Also in this arrangement, the manipulator devices may be integrated in the Einzel lens and this combined device may be more compact than providing two separate manipulator device and a separate Einzel lens.

In an arrangement of the charged particle system, the first and second planar lens substrate are grounded and the system is arranged for providing a negative voltage to the planar substrate (s) of the manipulator device (s), wherein said negative voltage is preferably in the range of -<NUM> Volt to -<NUM> Volt, or more preferably about -<NUM> Volt or -<NUM> kV.

In charged particle systems, so called secondary electrons may be generated by the charged particles of the charged particle beam when they hit or are in contact with surfaces in the charged particle system, for example the surface of the target. These secondary electrons may cause damage to the manipulator device (s). By providing the a negative voltage, for example of about -<NUM> kV to the planar substrate of the manipulator device (s), these secondary electrons may be deflected away from the manipulator device ( s ).

According a further arrangement there is provided a manipulator device for manipulating a charged particle beam in a charged particle system, such as a multi beam lithography system, according to any of the arrangements described above.

According to a further arrangement there is provided a charged particle system such as a multi beam lithography system, comprising:.

In an arrangement of the charged particle system, the charged particle system further comprises a planar current limiter substrate, comprising at least one current limiter aperture, wherein the current limiter planar substrate is arranged above the planar substrate of the manipulator device and the at least one current limiter aperture is arranged in alignment with the at least one through opening of the planar substrate of the manipulator device. In an arrangement of the charged particle system, the at least one current limiter aperture is smaller than the at least one through opening of the planar substrate of the manipulator device.

In an arrangement of the charged particle system, the charged particle system further comprises cooling tubes for transporting a cooling fluid, wherein said cooling tubes are arranged around the at least one current limiter aperture.

wherein the system is arranged for providing a voltage difference between the first planar lens substrate and the planar substrate of the first manipulator device and between the planar substrate of the second manipulator device and the second planar lens substrate for generating an Einzel lens for said beams.

In an arrangement of the charged particle system, the charged particle system further comprises cooling tubes for transporting a cooling fluid, wherein said cooling tubes are arranged between the first and the second manipulator device.

Both the first and the second manipulator device may deform due to thermal expansion. When the cooling tubes are arranged between the first and the second manipulator device, the manipulator devices will expand symmetrically. This may prevent the manipulator devices from bending.

In an arrangement of the charged particle system, the electrodes arranged in a first set of multiple first electrodes and in a second set of multiple second electrodes and the electronic control circuit form a single CMOS device.

wherein the first and the second manipulator device each form a single CMOS device.

According to a further arrangement there is provided a charged particle system such as a multi beam lithography system, comprising a manipulator device for manipulation of one or more charged particle beams, wherein the manipulator device comprises:.

The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which :.

<FIG> shows a schematic overview of a part of a charged particle multi-beam or multi-beamlet lithography system <NUM> according to an embodiment of the invention for processing at least a part of a target <NUM>, which may be a wafer. In an embodiment of the invention, the lithography system is without common cross-over of all the charged particle beams or beamlets and/or maskless.

The lithography system as shown in <FIG> comprises a charged particle source <NUM>, for example an electron source, for producing an expanding charged particle beam <NUM>. The expanding beam passes a collimator lens <NUM> for collimating the charged particle beam <NUM>.

Subsequently the collimated beam <NUM> impinges on an aperture array <NUM>, which blocks part of the collimated beam <NUM> for creating sub-beams <NUM>. The sub-beams <NUM> impinge on a further aperture array <NUM> for creating beamlets <NUM>. A condenser lens array <NUM> (or set of condenser lens arrays) is provided for focusing the sub-beams <NUM> towards a corresponding opening in the beam stop array <NUM> of end module <NUM>.

The beamlet creating aperture array <NUM> is preferably included in combination with a beamlet blanker array <NUM>, for example arranged close together with aperture array <NUM> before the blanker array <NUM>. The condenser lens or lenses <NUM> may focus sub-beam <NUM> either in or towards a corresponding opening in beam stop array <NUM> of end module <NUM>.

In this example, the aperture array <NUM> produces three beamlets <NUM> from sub-beam <NUM>, which strike the beam stop array <NUM> at a corresponding opening so that the three beamlets <NUM> are projected onto the target <NUM> by the projection lens system <NUM> in end module <NUM>. In practice a group of beamlets with a much larger number of beamlets may be produced by aperture array <NUM> for each projection lens system <NUM> in end module <NUM>. In a practical embodiment typically around fifty beamlets (for example <NUM> beamlets generated by a <NUM>×<NUM> aperture array) may be directed through a single projection lens system <NUM>, and this may be increased to two hundred or more.

However, it is also possible that the aperture array <NUM> produces only one beamlet <NUM> for each single projection lens system <NUM>. In that case, aperture array <NUM> may be omitted.

The beamlet blanker array <NUM> may deflect individual beamlets in a group of beamlets <NUM> at certain times in order to blank them. This is illustrated by blanked beamlet <NUM>, which has been deflected to a location on the beam stop array <NUM> near to but not at an opening.

It may be understood that the term beam in this document, in particular in the enclosed claims, may refer to beam <NUM>, sub-beam <NUM> and beamlets <NUM>. The charged particle optical column may be provided with one or more manipulator devices according to the invention at different locations in the charged particle system or in particularly at different locations in its optical column.

A manipulator device <NUM> according to the invention may be arranged behind the collimator lens <NUM> for:.

A manipulator device according to the invention may also be arranged behind the beamlet blanker array <NUM> (not shown in <FIG>).

A manipulator device <NUM> according to the invention may be provided as part of the end module <NUM> for providing a two dimensional deflection in the projection lens system <NUM> and, possibly enabling a vector scan of the beamlets in one group. Said dimension deflection may take place at a high frequency, i.e. a higher frequency than manipulation takes place in manipulator device <NUM>. <FIG> shows a schematical overview of a part of an embodiment of a manipulator device <NUM> according to the invention. This embodiment may be used as manipulator device <NUM> or manipulator device <NUM> in <FIG>.

The manipulator device <NUM> comprises a planar substrate <NUM> comprising an array of through openings <NUM> in the plane of the planar substrate. Through the through openings <NUM> one or more charged particle beamlets may pass. The through openings <NUM> extend substantially transverse to the surface of the planar substrate <NUM>. Each of openings <NUM> may be provided with electrodes <NUM> along the perimeter <NUM> of through opening <NUM>.

The through openings <NUM> may be grouped in so-called beam areas <NUM>. Adjacent to the beam areas <NUM> non-beam areas <NUM> are provided on the planar substrate <NUM>. In the non-beam areas electronic circuits (such as an electronic control circuit) may be at least partly provided to control the operation of the electrodes <NUM> in the beam area <NUM>.

The number of electrodes may vary but is preferably in the range of <NUM> - <NUM> electrodes or <NUM>. In general, the number of electrodes may be multiple of <NUM> or <NUM> electrodes, or may be equal to <NUM> or <NUM>, k being a natural number.

When the number of electrodes is even and the electrodes are arranged uniformly distributed along the perimeter of the through opening, it may be the case that a rotation of the electrodes <NUM> by <NUM> degrees around a centre axis of the through opening would yield the same distribution of the electrodes along the perimeter.

The manipulator device <NUM> may comprise an array of manipulators <NUM>, each comprising a through opening <NUM> and electrodes <NUM> arranged around the through opening <NUM>. The manipulators <NUM> preferably have lateral sizes ranging from approximately <NUM> micrometers to <NUM> micrometers, depending on their purpose. The manipulator may be regularly arranged in rows and columns, as for example is shown in <FIG>.

One of the challenges is to design electrodes with a fabrication process that is compatible with chip fabrication and electron optical design rules. Furthermore it is desirable to control thousands of beams without having thousands of external control wires.

The manipulator device may be manufactured using MEMS technology. This fabrication process is bipolar compatible allowing local electronics to be incorporated, for example the electronic control circuit. The local electronics (such as an electronic control circuit) may be arranged between the through openings or adjacent to the through openings or to the electrodes <NUM>.

<FIG> and <FIG> show a schematical overview of a part of an embodiment of a manipulator according to the invention. In the example of <FIG> the through opening <NUM> is provided with <NUM> electrodes <NUM> - <NUM> along the perimeter of the through opening <NUM>. When operational, a beam may enter the through opening <NUM> in a direction into the paper. This direction may be parallel with the optical axis of the optical column or with a central axis of the through opening. The cross-sectional area of one beam passing the through opening <NUM> is indicated by <NUM> in <FIG>. In <FIG> the cross-sectional area of multiple beams passing the through opening <NUM> is indicated by <NUM>. In <FIG> the cross-sectional area of only four beams are indicated, but more beam could pass through the through opening, for example <NUM> beams.

A plane <NUM> may be defined parallel with the central axis of the through opening and may comprise said central axis. It may be understood that all planes and lines mentioned in this document are imaginary. A first set of first electrodes <NUM>-<NUM> has been arranged along a first part <NUM> of the perimeter and a second set of second electrodes <NUM>-<NUM> has been arranged along a second part <NUM> of the perimeter. The first set of first electrodes <NUM>-<NUM> is arranged opposite to the second set of electrodes <NUM>-<NUM> with respect to the plane <NUM>. The plane <NUM> is defined centrally between the first and second set of electrodes.

The electrodes according to this example, are arranged substantially symmetrically with respect to the plane <NUM> and the electrodes are uniformly distributed along said perimeter, as can be seen in <FIG> and <FIG>. A voltage may be applied or provided to each of the electrodes by an electronic control circuit (not shown in <FIG>). To the voltages provided to each electrode may be referred to as V<number of the electrode>, for example, a voltage V306 may be applied to electrode <NUM> and a voltage V309 may be applied to electrode <NUM>.

The electronic control circuit may be arranged for providing voltage differences to pairs of a first electrode and a second electrode in dependence of positions of the respective electrodes along the perimeter of the through opening. It may be the case that, the first electrode of a pair from the first set and the second electrode of said pair from the second set are be arranged opposite to each other with respect to plane <NUM>. For example, in <FIG>, first electrode <NUM> from the first set of electrodes <NUM>-<NUM> and second electrode <NUM> from the second set of electrodes <NUM>-<NUM> are arranged opposite with respect to plane <NUM>. A distance between the electrodes of the pair is indicated by D4.

The electronic control circuit is arranged for providing said voltage differences to said pair of first electrode <NUM> and second electrode <NUM> in dependence of the distance D4, wherein preferably said voltage differences are directly proportional to said distance D4.

In <FIG>, a distance between electrode <NUM> and plane <NUM> is indicated by arrow D1, while a distance between electrode <NUM> and plane <NUM> is indicated by D2. And a distance between electrode <NUM> and the plane is indicated by D3. The electronic control circuit may be arranged for providing voltages to the electrodes in dependence of a distance between a respective electrode and said plane.

For example in <FIG>, because the distances D1 and D2 are different, the voltage V306 and V309 provided by the electronic control circuit is also different. The voltages V309 and V303 may be (substantially) identical, since the distances D2 and D3 are also (substantially) identical.

In an embodiment, the voltages increase with said distance, preferably proportionally. In the example of <FIG>, voltage V306 may be higher than V309 or may be equal to the ratio D1/D2 times the voltage V309. This may also be applicable to the other electrodes <NUM>, mutatis mutandis.

Among the electrodes <NUM> a first electrode from the first set of electrodes <NUM>-<NUM> (i.e. a set of the so-called first electrodes) and a second electrode from the second set of electrodes <NUM>-<NUM> (i.e. a set of the so-called second electrodes) may be arranged diametrically across the through opening <NUM>. For example, in <FIG>, first electrode <NUM> from the first set and second electrode <NUM> from the second set are arranged diametrically. A line connecting the (positions of) the first electrode <NUM> and second electrode <NUM> has been indicated by <NUM> in <FIG>. The plane <NUM> and this line <NUM> define an angle alpha (α), as is shown in <FIG>. It may be understood that the angle alpha (α) depends on the distance between electrode <NUM> and plane <NUM>. The electronic control circuit may be arranged for providing voltages to the electrodes in dependence of said angle alpha (α), or in particular in dependence of sin(α).

A line connecting an electrode and the centre of the through opening may define an angle with said plane. In the example of <FIG> is an angle beta (β) defined by the plane <NUM> and line <NUM> connecting electrode <NUM> and the centre of the through opening <NUM>. The electronic control circuit may be arranged for providing a voltage to an electrode in dependence of said angle beta (β). The voltage may be (directly) proportional to sin(β).

It may be the case that the voltages provided by the electronic control circuit is a function of angle beta (β), or more particular the provided voltage is a function of the sinus of angle beta (β), such as: V(β) = Vmax·sin(β).

<FIG> shows a schematical overview of a part of an embodiment of a manipulator according to the invention.

The electronic control circuit may be arranged for providing a voltage V to two electrodes from the first set, and preferably a voltage -V to two electrodes from the second set. In the example of <FIG>, voltage V309 may thus be identical to voltage V303. And voltage V313 may thus also be identical to voltage V319 and V313 = - V309. The electronic control circuit may be arranged for providing a positive voltage V to the first electrode and a negative voltage -V to the second electrode of a pair. In the example of <FIG>, voltage V307 may thus be V307 = - V315.

The electrodes <NUM> may comprise two electrodes arranged along the perimeter of the through opening and substantially on the plane <NUM> and the electronic control circuit may be arranged for providing a voltage to each of said two electrodes, said voltage preferably being an offset voltage. The offset voltage may be substantially equal to <NUM> Volt. In the example of <FIG>, electrodes <NUM> and <NUM> are arranged substantially on plane <NUM> and may be connected with the ground potential, providing a voltage of at least substantially <NUM> volt, as is indicated by <NUM> in <FIG>.

However, as explained below, the offset voltage may also be around - <NUM> kV with respect to the ground, when the planar substrate <NUM> is part of an Einzel lens. The voltages of the electrodes <NUM> may be defined with respect to the offset voltage. In that case, when V306 is said to be <NUM> volt and the offset voltage is - <NUM> kV, it indicates a voltage V306 = - <NUM> volt with respect to the ground.

In <FIG>, the electrical field lines of the electrical field generated by the electrodes <NUM> have been indicated by arrows <NUM>. Because the voltages may be provided to the electrodes <NUM> as described above, the electrical field may substantially homogeneous. Because the electrical field is substantially homogeneous across the through opening, the manipulation of the charged particles that passes through the through opening will take place regardless the position of the charged particles in the through opening. This improves the accuracy of the manipulation of the beamlets.

However, the through opening <NUM> may be a circle (as is depicted in the figures), but may also have an ellipse shape or any other shape, for example because of errors in the production process. In that case, the voltages provided by the electronic control circuit may be adjusted to correct these errors in order to obtain a substantially homogeneous electrical field.

Furthermore, it may be the case that the beamlets are not centrally projected on the manipulator or does not have a circular cross-sectional area (not indicated in the figures). In that case, the voltages provided by the electronic control circuit may be adjusted in order to correct theses errors.

In the example of <FIG>, the electronic control circuit comprises a number of resistors <NUM> connected in series. The number of resistors may be equal to the number of electrodes. The resistance of these resistors may be selected in order to provide a voltage to each of said electrodes which voltage changes around the through opening. The voltage of a particular electrode is a function of the position of the electrode around the through opening. Such a function be may a sinus function.

An electrode, for example electrode <NUM>, may be connected to a voltage V306 = Vmax via connection <NUM>, while another electrode, for example electrode <NUM>, may be connected to a voltage V316 = - Vmax via connection <NUM>. The voltage Vmax may be in the range of <NUM>-<NUM> or in the range of <NUM>-<NUM>, or about <NUM> Volt.

Electrodes <NUM> and <NUM> may be provided with the same voltage. They may be grounded or provided with a voltage V310 = V311 = <NUM> Volt. In this way, four voltage dividers have been arranged for dividing voltages Vmax and -Vmax into respective voltages.

This yields a relatively simple electronic control circuit, which may be easily provided around each through opening <NUM>, for example in the planar substrate <NUM> of the the manipulator device <NUM> of <FIG>. The electronic control circuit may be provided on the non-beam area <NUM> of the planar substrate <NUM> or may be provided around the through opening <NUM> in the beam-area <NUM>.

It may be understood that the voltages provided to the electrodes of one through opening may also be provided to the electrodes of another through opening, preferably by the same electronic control circuit.

Between adjacent electrodes <NUM> gaps <NUM> may be provided. The perimeter of the through opening may thus be covered by electrodes <NUM> and gaps <NUM>. An electrode-to-gap ratio may be defined as a first area of the perimeter covered by the electrodes divided by a second area of the perimeter covered by the gaps. The electrode-to-gap ratio may be considered as a measure for the distance between adjacent electrodes. When the distance between adjacent electrodes is small, a more homogeneous electrical field may be provided, but any cross-over between the adjacent electrodes is also more likely. An optimal balance has been found at an electrode-to-gap ratio in the range of <NUM>-<NUM>, or preferably substantially <NUM>.

In order to (further) minimize the cross-talk between an electrode and other circuits in the vicinity of the electrode, or between electrodes provided around one or more through openings, the manipulator device may be provided with a cross-talk shield <NUM> (not shown in <FIG>, but in <FIG>). The cross-talk shield may comprise a planar shield substrate comprising an array of through openings in the plane of the planer shield substrate, wherein the through openings of the planer shield substrate are arranged in alignment with the through openings of the planar substrate.

The cross-talk shield provides an electrical shielding of electrodes <NUM> against electro(magnetic) fields of any other circuitry in the vicinity of the electrodes. It appears that the shielding is at its optimum when a distance between the planar substrate and the planar shield substrate is smaller than <NUM> micrometer and/or a thickness of the shield planar substrate is about a diameter of the through openings of the planar substrate.

<FIG> and <FIG> show a schematical overview of two examples of an electronic control circuit for use in a manipulator device according to the invention. In <FIG>, the electronic control circuit comprises a first operational amplifier <NUM> and a second operational amplifier <NUM>. Each operational amplifier may be grounded and may be connected to a DAC (digital-to-analogue) converter, indicated by <NUM> and <NUM> respectively. Each DAC converter may be controlled via a serial/parallel+ bus interface (SPI), indicated by <NUM> and <NUM> respectively.

The DAC converter <NUM> connected to the first operational amplifier <NUM> may provide a positive voltage Vmax and the DAC converter <NUM> connected to the second operational amplifier <NUM> may provide a negative voltage - Vmax. Both operational amplifiers may comprise resistors <NUM> as a feedback resistor. In that case, the amplified voltages Vmax and -Vmax may be divided into voltage parts. Each of these voltages (or voltage parts) may be fed to the electrodes <NUM> of a through opening <NUM> as indicated by arrows <NUM> and <NUM>.

It may be understand that each voltage provided by the first or second operational amplifier may be fed to two electrodes among the electrodes <NUM>. In this way, fewer resistors may be required in comparison with the example of <FIG>. Furthermore, each voltage may also be fed to two electrodes of another through opening of the manipulation device. This would further reduce the number of resistors required.

In the embodiment of <FIG>, the two operational amplifiers <NUM> and <NUM> are connected to a single DAC converter <NUM>. The first amplifier <NUM> is directly connected to the DAC converter <NUM> to receive a control signal from the DAC converter <NUM>. The second operational amplifier <NUM> is connected to the DAC converter <NUM> via a polarity inverter <NUM> to receive the same control signal from the DAC converter <NUM> but with an inverted polarity. The DAC converter <NUM> may be controlled via a serial/parallel bus interface (SPI), indicated by <NUM>.

It may be understood that the electronic control circuits of <FIG> and <FIG> are relatively simple with few elements. Therefore, they can be easily integrated with the planar substrate of the manipulator device. At least a part of the circuitry of the <FIG> and <FIG>, for example the operational amplifiers and the resistors, may be provided in the non-beam area <NUM> of the manipulator device.

<FIG> shows a schematical overview of a part of an embodiment <NUM> of a charged particle system according to the invention. The system may be provided with a first manipulator device <NUM>-<NUM> according to one of the embodiments described above and with a second manipulator device <NUM> also according to one of the embodiments described above.

The first manipulator device <NUM>-<NUM> may be arranged for deflecting one or more charged particle beams in an x-direction and the second manipulator device <NUM> may be arranged for deflecting one or more charged particle beams in a y-direction, wherein the x-direction is perpendicular to the y-direction. Both x-direction and y-direction may be perpendicular to the direction of the beam, indicated by arrow <NUM>, which may be parallel with the optical axis of the optical column or parallel with the central axis of the through opening.

A first planar lens substrate <NUM> and a second planar lens substrate <NUM> may be arranged on opposite sides of the manipulator devices <NUM>-<NUM> and <NUM>. Each planar lens substrate may comprise at least one planar lens aperture or an array of planar lens apertures, wherein the planar lens apertures are arranged in alignment with the through openings of the planar substrate of the manipulator(s).

The first planar lens substrate and the second planar lens substrate may form together with the manipulator device(s) a lens, e.g. an Einzel lens for focusing one or more beams. A voltage difference may be applied between the first planar lens substrate <NUM> and the first manipulator device <NUM>-<NUM>, and another voltage difference may be applied between the second manipulator device <NUM> and the second planar lens substrate <NUM>, in such way that a positive lens effect is generated. In this way, the manipulator device(s) is/are part of the lens or lens arrangement and a more compact device may be obtained.

In an embodiment, the first planar lens substrate <NUM> and the second planar lens substrate <NUM> are grounded while the manipulator device(s) are provided with an off-set voltage of, for example, -<NUM> kilovolt.

A planar current limiter substrate <NUM> may be provided, which may comprising at least one current limiter aperture or an array of current limiter apertures, wherein the current limiter planar substrate is arranged above the first planar lens substrate, wherein the current limiter aperture is arranged in alignment with the through opening of the planar substrate of the manipulator(s).

Cooling tubes <NUM> (or a cooling system) for cooling one or more planar substrates may further be provided. The cooling system may comprise the cooling tubes <NUM> adjacent to the through openings and a pump for pumping a cooling fluid (such as water) through the cooling tubes.

A cooling tube <NUM> may be arranged between the first and the second manipulator device, preferably in a circle around the central axis of the through openings.

As can be seen in <FIG>, the cross-sectional area of beam <NUM> on the planar current limiter substrate <NUM> is larger than the respective current limiter aperture. Some of the charged particles in the beam <NUM> may therefore be absorbed by the planar current limiter substrate <NUM>.

Using the above-mentioned positive lens, the remaining beam may be deflected. In <FIG> this is illustrated by a beam axis <NUM> that changes its direction. The beam <NUM> passes through the through openings of the manipulator device(s) without hitting or contacting the planar substrates thereof.

In an embodiment, the beam may be deflected in the x- and y-direction by first manipulator device <NUM> and the second manipulator device <NUM>, during the exposure of the target.

Both manipulator devices <NUM>-<NUM> and <NUM> may be provided with respective cross-talk shield <NUM> and <NUM>. The cross-talk shields may provide an electrical shielding of the circuits of the manipulator devices against any electro (magnetic) fields of any other circuitry in the vicinity.

<FIG> shows a schematic overview of a part of another embodiment of a charged particle system according to the invention. The system may comprise a charged particle source <NUM> and collimation means <NUM> for collimating the charged particle beam <NUM>. The collimated beam <NUM> may impinge on an aperture array <NUM>, which blocks part of the collimated beam <NUM> for creating a sub-beam <NUM>.

A deflector <NUM> may be provided for deflecting the sub-beam <NUM>. In an embodiment, the deflector <NUM> may also comprise a manipulator device according to the invention. As in the embodiment of <FIG>, in <FIG>, a planar current limiter substrate <NUM> is provided and a first planar lens substrate <NUM> and a second planar lens substrate <NUM> are arranged on opposite sides of the manipulator devices <NUM> and <NUM>. Their working has been described with reference to <FIG>.

The manipulated sub-beam <NUM> may then pass through aperture <NUM>, by which the beamlets <NUM> are generated. Two deflectors <NUM> and <NUM> may be provided for deflecting the beamlets (or a group of beamlets) in an x- and a y-direction respectively. Some beamlets may be deflected by blanking deflectors (not shown separately in <FIG>) such that they do not pass through the beam stop substrate <NUM>.

The beamlets that do pass through the beam substrate <NUM> are focused or projected by projection lens system <NUM> on target <NUM>. Target <NUM> may be wafer and may be placed on a moveable platform <NUM>, which may be movable in the x- and y- direction with respect to the projection lens system <NUM>.

The system of <FIG> may further be provided with cooling tubes (or a cooling system) for cooling one or more planar substrates. The cooling system may comprise the cooling tubes <NUM> and a pump for pumping a cooling fluid (such as water) through the tubes.

<FIG> shows a schematic overview of a part of an embodiment of a manipulator according to the invention. In <FIG> half of a through opening <NUM> is shown with only three electrodes <NUM> and only two gaps <NUM> for clarity reasons. The through opening may be provided with more electrodes as is described above.

The electrodes <NUM> may be produced as a chip and one or more metal layers may be used for supplying the voltages to the electrodes. In the example of <FIG>, six metal layers <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are depicted. Between the metal layers, electrically insulating layers have been provided. Connections between the metal layers may be provided by one or more vias <NUM>.

The electrodes may be provided partly in and on the planar substrate. Together with the metal layers the vias <NUM> may form pillars <NUM> that extend in the inner surface of through opening <NUM>. In this way, the electrical field is not only generated in one plane, for example in the plane of metal layer <NUM>, but in a larger portion of the through opening. The charged particles of the beam passing through will thus be affected longer (and thus more) by the electrical field when the charged particles pass through the through opening <NUM>.

The electrodes <NUM> are preferably made from molybdenum, however they may also be made from other conducting materials. The electrodes <NUM> may be approximately <NUM> micrometers thick, and the electrodes may be made by anisotropic etching of the molybdenum using reactive ion etching.

The electrodes <NUM> arranged in a first set of multiple first electrodes and in a second set of multiple second electrodes and the electronic control circuit may form a single CMOS device.

According to an aspect of the invention a charged particle system, such as a multi beam lithography system, is provided, comprising:.

In an embodiment, the system further comprises cooling tubes <NUM> arranged for transport a cooling fluid, wherein the cooling tubes <NUM> are arranged between the first and the second manipulator device.

In an embodiment, the system further comprises an electronic control circuit arranged for providing different voltages to at least two first electrodes of the first set of multiple first electrodes.

In an embodiment, the first and the second manipulator device each form a single CMOS device.

It may be understood that the embodiments of a manipulator, of the first and/or second manipulator and/or the electronic control circuit as described above are also applicable to this charged particle system.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention, which is defined by the appended claims.

Claim 1:
A manipulator device (<NUM>, <NUM>; <NUM>, <NUM>) for manipulation of one or more charged particle beams (<NUM>), wherein the manipulator device comprises:
a planar substrate (<NUM>) comprising at least one through opening (<NUM>) in the plane of the planar substrate, wherein each through opening is arranged for passing at least one charged particle beam there through and each through opening is provided with respective sets of electrodes (<NUM>; <NUM>-<NUM>) along respective parts of a perimeter (<NUM>) of said through opening; and
characterized in that each set of electrodes is provided with pluralities of resistors (<NUM>), each plurality of resistors being arranged as a voltage divider and provided in the planar substrate, wherein the resistances of each plurality of resistors are for providing voltages to the corresponding set of electrodes, such that the voltage of a particular electrode in each of the sets of electrodes is a function of the sine of the angular position of the particular electrode around the respective through opening.