WO2018167936A1 - Exposure device, lithographic method, and device manufacturing method - Google Patents

Abstract

This exposure device that irradiates and exposes a target (W) with an electron beam (EB3) is provided with an irradiation device (20) having: a blanking aperture array (29) having a plurality of openings (28a) which are arranged, on an X-Y plane parallel to a surface of a target (W), along an X-axis direction and a direction crossing the X-axis direction; and optical systems (38A, 38B, 38C, 38D) which irradiate the target (W) with electron beams (EB3) that have respectively passed through the plurality of openings (28a), wherein the plurality of openings (28a) are arranged so that the positional misalignment of the plurality of electron beams to be irradiated onto the target is less than an allowable value. The arrangement of the plurality of openings (28a) is determined by considering positional information about the beams to be irradiated onto the target, the positions of the beams being determined by a coulomb force that acts between the electron beams and obtained by varying the distances between the electron beams.

Description

Exposure apparatus, lithography method, and device manufacturing method

The present invention relates to an exposure apparatus, a lithography method, and a device manufacturing method, and more particularly, an exposure apparatus that irradiates a target by irradiating a charged particle beam, a lithography method that cuts a line pattern using the exposure apparatus, and a lithography method. The present invention relates to a device manufacturing method including a lithography process in which exposure of a target is performed.

Recently, complementary lithography using, for example, an immersion exposure technique using an ArF light source and a charged particle beam exposure technique (for example, an electron beam exposure technique) has been proposed. In complementary lithography, for example, a simple line and space pattern (hereinafter, abbreviated as an L / S pattern as appropriate) is formed by using double patterning or the like in immersion exposure using an ArF light source. Next, a line pattern is cut or a via is formed through exposure using an electron beam.

In complementary lithography, a charged particle beam exposure apparatus equipped with a multi-beam optical system can be suitably used (for example, see Patent Documents 1 and 2). However, a Coulomb force (Coulomb interaction) works between a plurality of beams irradiated from the multi-beam optical system. In addition to this, when actually performing the exposure, the on / off states of each of the plurality of beams are freely changeable and change from moment to moment according to the target pattern. As a result, the interaction between the beams is also variable and changes every moment.

JP 2015-133400 A US Patent Application Publication No. 2015/0200074

According to the first aspect, there is provided an exposure apparatus that irradiates a target by irradiating a charged particle beam, the first direction in a predetermined plane parallel to the surface of the target and the first direction in the predetermined plane. A beam shaping member having a plurality of openings arranged along the intersecting second direction; and an optical system for irradiating the target with the charged particle beam respectively passing through the plurality of openings. Comprises an irradiation device arranged so that positional deviation of the plurality of charged particle beams irradiated to the target is less than an allowable value, and the arrangement of the plurality of openings changes the distance between the charged particle beams There is provided an exposure apparatus that is determined in consideration of positional information of the charged particle beam resulting from the Coulomb force acting between the charged particle beams.

According to the second aspect, the target is exposed by an exposure apparatus to form a line and space pattern on the target, and the line and space pattern is configured using the exposure apparatus according to the first aspect. A line pattern cutting is provided.

According to a third aspect, there is provided a device manufacturing method including a lithography process, wherein in the lithography process, a device manufacturing method is performed in which exposure to a target is performed by the lithography method according to the second aspect.

It is a figure which shows schematically the structure of the electron beam exposure apparatus which concerns on one Embodiment. It is a perspective view which shows the exposure system with which the electron beam exposure apparatus of FIG. 1 is provided. It is a figure which shows a part of electron beam irradiation apparatus with the coarse / fine movement stage with which the wafer shuttle was mounted | worn. It is a figure which shows the structure of an optical system column (multi-beam optical system). FIG. 5A is a plan view showing the beam shaping aperture plate, and FIG. 5B is an enlarged view of the inside of a circle C in FIG. 5A. 6A and 6B show the basis for determining the pitch px of the opening 28a in the X-axis direction and the pitch in the direction inclined by a predetermined angle with respect to the opening 28aX axis (interval between adjacent openings 28a). It is a figure for demonstrating. It is a perspective view which shows the state by which the wafer shuttle was mounted | worn to the coarse / fine movement stage mounted on the surface plate. It is a perspective view which shows the coarse / fine movement stage of FIG. 7 from which the wafer shuttle was removed from the fine movement stage. It is a figure which expands and shows the fine movement stage mounted on the surface plate. It is a figure which shows the state which removed the fine movement stage and the magnetic-shielding member from the coarse / fine movement stage shown by FIG. FIGS. 11A and 11B are diagrams (No. 1 and No. 2) for explaining the configuration of the first measurement system. It is a block diagram which shows the input / output relationship of the main controller which comprises the control system of an electron beam exposure apparatus. FIG. 13A is a diagram showing a state in which all the beams of the optical system column are simultaneously irradiated on the L / S pattern in complementary lithography, and FIG. 13B is a diagram showing a predetermined number of line patterns. It is a figure which shows the state in which the cut pattern was formed in the same Y position. 14A and 14B are diagrams for explaining a series of flows when a cut pattern is formed at the same Y position on a predetermined number of continuous line patterns (No. 1 and No. 2). It is. FIGS. 15A and 15B are diagrams for explaining a series of flows when a cut pattern is formed at the same Y position on a predetermined number of continuous line patterns (No. 3 and No. 4). It is. It is FIG. (5) for demonstrating a series of flows in the case of forming a cut pattern in the same Y position on the continuous predetermined number of line patterns. FIGS. 17A and 17B are diagrams for explaining other arrangement examples of the openings on the beam shaping aperture plate. 18 (A) and 18 (B) show an exposure apparatus according to the first modification that controls the irradiation position on the L / S pattern of the main beam by using the sub beam that passes through the auxiliary opening of the beam shaping aperture plate. It is a figure for demonstrating the exposure method. FIGS. 19A and 19B are views for explaining a beam shaping aperture plate provided in the exposure apparatus according to the second modification. FIGS. 20A, 20B, and 20C are diagrams for explaining the principle of correcting the X shift amount of the beam using the discarded cut beam in the exposure apparatus according to the second modification. is there. It is a flowchart for demonstrating one Embodiment of a device manufacturing method.

Hereinafter, an embodiment will be described with reference to FIGS. FIG. 1 schematically shows a configuration of an electron beam exposure apparatus 100 according to an embodiment. Since the electron beam exposure apparatus 100 includes an electron beam optical system as will be described later, hereinafter, the Z axis is taken in parallel to the optical axis of the electron beam optical system, and exposure will be described later in a plane perpendicular to the Z axis. The scanning direction in which the wafer W is moved is the Y-axis direction, the direction orthogonal to the Z-axis and the Y-axis is the X-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are θx and θy, respectively. And the θz direction will be described.

In this embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to an electron beam, and a beam using charged particles such as an ion beam may be used.

The electron beam exposure apparatus 100 includes a vacuum chamber 80 and an exposure system 82 housed in an exposure chamber 81 defined by the vacuum chamber 80. FIG. 2 shows a perspective view of the exposure system 82.

The exposure system 82 includes a stage device 83 and an electron beam irradiation device 92 as shown in FIGS. The electron beam irradiation device 92 includes a cylindrical barrel 93 shown in FIG. 2 and an electron beam optical system inside the barrel 93.

The stage device 83 includes a coarse / fine movement stage 85 on which a wafer shuttle 10 that can hold and move a wafer is detachably mounted. The electron beam irradiation device 92 is a wafer shuttle mounted on the coarse / fine movement stage 85. In this configuration, the wafer W held by 10 is exposed to an electron beam.

Here, as will be described in detail later, the wafer shuttle 10 is a holding member (or table) that holds the wafer by electrostatic adsorption. The holding member is transported while holding the wafer, and a plurality of exposure chambers including the exposure chamber 81 (for exposure chambers other than the exposure chamber 81, starting from a measurement chamber (not shown) in which predetermined pre-measurement is performed. Reciprocate back and forth. Therefore, in this embodiment, this holding member is called a wafer shuttle.

As shown in FIG. 2, the stage device 83 includes a surface plate 84, a coarse / fine movement stage 85 that moves on the surface plate 84, a drive system that drives the coarse / fine movement stage 85, and positional information of the coarse / fine movement stage 85. And a position measurement system for measuring. Details of the configuration of the stage device 83 will be described later.

As shown in FIG. 2, the lens barrel 93 of the electron beam irradiation apparatus 92 is lowered by a metrology frame 94 made of an annular plate member having three convex portions formed at intervals of a central angle of 120 degrees on the outer peripheral portion. It is supported from. More specifically, the lowermost end portion of the lens barrel 93 is a small-diameter portion whose diameter is smaller than the portion above it, and the boundary portion between the small-diameter portion and the portion above it is a stepped portion. Yes. Then, with the small diameter portion inserted into the circular opening of the metrology frame 94 and the bottom surface of the stepped portion in contact with the upper surface of the metrology frame 94, the lens barrel 93 is moved from below by the metrology frame 94. It is supported. As shown in FIG. 2, the metrology frame 94 has three suspension support mechanisms 95a, 95b, and 95c (flexible structure connecting members) each having a lower end connected to each of the three convex portions described above. It is supported in a suspended state from the top plate (ceiling wall) of the vacuum chamber 80 that partitions the exposure chamber 81 (see FIG. 1). That is, in this way, the electron beam irradiation apparatus 92 is supported by being suspended from the vacuum chamber 80 at three points.

The three suspension support mechanisms 95a, 95b, and 95c are, as representatively shown for the suspension support mechanism 95a in FIG. (Vibration proof part) It has the wire 97 which consists of steel materials which each one end was connected to the lower end of 96, and the other end was connected to the metrology frame 94. The anti-vibration pads 96 are fixed to the top plate of the vacuum chamber 80 and each include an air damper or a coil spring.

In the present embodiment, among vibrations such as floor vibration transmitted from the outside to the vacuum chamber 80, most of vibration components in the Z-axis direction parallel to the optical axis of the electron beam optical system are absorbed by the vibration isolation pad 96. Therefore, high vibration isolation performance can be obtained in a direction parallel to the optical axis of the electron beam optical system. The natural frequency of the suspension support mechanism is lower in the direction perpendicular to the optical axis than in the direction parallel to the optical axis of the electron beam optical system. Since the three suspension support mechanisms 95a, 95b, and 95c vibrate like a pendulum in the direction perpendicular to the optical axis, the vibration isolation performance in the direction perpendicular to the optical axis (floor vibration transmitted from the outside to the vacuum chamber 80) The length of the three suspension support mechanisms 95a, 95b, and 95c (the length of the wire 97) is set to be sufficiently long so that the vibration (such as the ability to prevent vibrations from being transmitted to the electron beam irradiation device 92) is sufficiently high. is doing. With this structure, high vibration isolation performance can be obtained and the mechanical unit can be significantly reduced in weight, but the relative position between the electron beam irradiation device 92 and the vacuum chamber 80 may change at a relatively low frequency. In order to maintain the relative position between the electron beam irradiation device 92 and the vacuum chamber 80 in a predetermined state, a non-contact type positioning device 98 (not shown in FIGS. 1 and 2; see FIG. 12) is provided. Yes. The positioning device 98 can be configured to include a 6-axis acceleration sensor and a 6-axis actuator, as disclosed in, for example, International Publication No. 2007/077920. The positioning device 98 is controlled by the main controller 50 (see FIG. 12). Thus, the relative positions of the electron beam irradiation device 92 with respect to the vacuum chamber 80 in the X-axis direction, the Y-axis direction, and the Z-axis direction, and the relative rotation angles around the X-axis, Y-axis, and Z-axis are constant (predetermined). The state is maintained.

3 shows a part of the electron beam irradiation apparatus 92 together with the coarse / fine movement stage 85 on which the shuttle 10 is mounted. In FIG. 3, the illustration of the metrology frame 94 is omitted. The electron beam irradiation device 92 includes an electron beam optical system including a lens barrel 93 and m (m is 100, for example) optical system columns 20 arranged in an array on the XY plane in the lens barrel 93. I have. Each optical system column 20 includes a multi-beam optical system that can irradiate n beams (n is, for example, 5000) that can be individually turned on / off and can be deflected. Hereinafter, for convenience, the multi-beam optical system is referred to as a multi-beam optical system 20, an optical system column (multi-beam optical system) 20, or a multi-beam optical system (optical system column) 20, using the same reference numerals as those of the optical system column. write.

FIG. 4 shows the configuration of the optical system column (multi-beam optical system) 20. The optical system column (multi-beam optical system) 20 includes a cylindrical housing (column cell) 21, an electron gun 22 and an optical system 23 housed in the column cell 21.

The optical system 23 includes a first aperture plate 24, a primary beam shaping plate 26, a beam shaping aperture plate 28, a blanker plate 30, and a final aperture 32 arranged in a predetermined positional relationship below the electron gun 22 from top to bottom. Is provided. Among these, the beam shaping aperture plate 28 and the blanker plate 30 are arranged close to each other.

An asymmetric illumination optical system 34 is disposed between the first aperture plate 24 and the primary beam shaping plate 26. Electromagnetic lenses 36A and 36B are arranged between the primary beam shaping plate 26 and the beam shaping aperture plate 28 at a predetermined interval in the vertical direction. Electromagnetic lenses 38A and 38B are arranged between the blanker plate 30 and the final aperture 32 at a predetermined interval in the vertical direction. Further, below the final aperture 32, electromagnetic lenses 38C and 38D are arranged at a predetermined interval in the vertical direction. Inside the electromagnetic lens 38D, a stage feedback deflector 40 is disposed at a somewhat higher position and substantially concentric with the electromagnetic lens 38D.

The electron gun 22 emits an electron beam EB ₀ having a predetermined acceleration voltage (for example, 50 keV). The electron beam EB ₀ is, by passing through the opening 24a of the first aperture plate 24 is formed into symmetrical circular cross section around the optical axis AX1.

The asymmetric illumination optical system 34 is an electron beam obtained by transforming an electron beam EB ₀ formed into a circular cross section into a vertically long cross-sectional shape that is long in one direction (for example, the X-axis direction) and short in the other direction (for example, the Y-axis direction). EB ₁ is generated.

The asymmetric illumination optical system 34 can be configured by, for example, an electrostatic quadrupole lens group that generates an electrostatic quadrupole field near the optical axis AX1. Section by appropriately adjusting the electrostatic quadrupole field generated by an asymmetric illumination optical system 34 can be molded to the electron beam EB ₁ portrait.

The electron beam EB ₁ is applied to a region including a slit-shaped opening 26 a long in the X-axis direction formed at the center of the disk-shaped primary beam shaping plate 26 in the Y-axis direction. The electron beam EB ₁ passes through the opening 26a of the primary beam shaping plate 26 to be shaped into the electron beam EB ₂ , and is imaged on the beam shaping aperture plate 28 by the electromagnetic lens 36A and the electromagnetic lens 36B. Irradiation is performed on an irradiation region extending in the X-axis direction corresponding to an arrangement region of an opening, which will be described later, of the shaping aperture plate 28.

The beam shaping aperture plate 28 is provided with a plurality of openings at positions corresponding to the openings 26 a of the primary beam shaping plate 26. More specifically, in the beam shaping aperture plate 28, as shown in the plan view of FIG. 5A, a large number of openings 28a are formed at predetermined intervals in a parallelogram region extending in the X-axis direction. Is formed. The openings 28a are formed from a predetermined number (for example, 1000) of openings 28a arranged side by side in the X-axis direction at a predetermined pitch of 5 px, as shown in FIG. 5 rows of opening rows are arranged at a predetermined interval of 6 py in the Y-axis direction. However, the openings 28a in the opening row adjacent to the −Y side are shifted by px in the + X direction so that the openings 28a do not overlap in the X-axis direction. Here, when the dimension px in the X-axis direction of the opening 28a is p = p, the dimension py in the Y-axis direction is p / 2 to p, for example, 4p / 7. In this case, the distance between the closest openings 28a is about 3.57p, and the shape of the opening 28a is a rectangle (rectangle). Note that py = p may be satisfied, and at this time, the shape of the opening 28a is a square. Here, p is, for example, 0.5 μm to 2 μm, preferably 1 μm or 1.5 μm. The basis for determining the pitch px of the openings 28a and the distance between the closest openings 28a (the pitch in the direction inclined by a predetermined angle with respect to the X axis) as described above will be described later.

Returning to FIG. 4, a blanker plate 30 is disposed below the beam shaping aperture plate 28. In the blanker plate 30, openings 30a are formed in portions corresponding to the plurality of openings 28a of the beam shaping aperture plate 28, respectively. Each opening 30a is formed larger than the opening 28a, and an electron beam that has passed through the opening 28a can pass therethrough.

Then, on both sides of the Y-axis direction of each opening 30a, a pair of blanking electrodes for deflecting the electron beam EB ₃ emitted from the opening 30a, respectively. Although not shown, each blanking electrode is connected to a drive circuit via a wiring and a terminal. The blanking electrode and the wiring are integrally formed by patterning a conductive film having a thickness of about several μm to several tens of μm on the main body of the blanker plate 30. The blanking electrode is preferably formed on the surface of the blanker plate 30 (main body) on the downstream side of the electron beam in order to prevent damage due to irradiation of the electron beam.

When applying a voltage to the blanking electrode, the electron beam EB ₃ having passed through the opening 30a is bent greatly. As a result, as shown in FIG. 4, the electron beam EB _off bent by the blanking electrode is guided to the outside of the circular opening 32a of the final aperture 32 arranged below the blanker plate 30, and the final aperture. 32. The opening 32 a is formed near the optical axis of the final aperture 32.

On the other hand, when no voltage is applied to the blanking electrode, the electron beam EB ₃ passes through the opening 32 a of the final aperture 32. That is, on / off of each electron beam EB ₃ can be controlled by whether or not a voltage is applied to each blanking electrode. Two electromagnetic lenses, that is, a first electromagnetic lens 38A, a second electromagnetic lens 38B, a third electromagnetic lens 38C, and a fourth electromagnetic lens 38D are arranged above and below the final aperture 32, respectively. By the cooperation of the first to fourth electromagnetic lenses 38A to 38D, images of many openings 28a of the beam shaping aperture plate 28 are reduced at a predetermined reduction magnification γ and formed on the surface of the wafer W. The Hereinafter, the beam shaping aperture plate 28 and the blanker plate 30 are collectively referred to as a blanking aperture array 29 as appropriate.

The stage feedback deflector 40 disposed below the final aperture 32 is an electrostatic deflector having a pair of electrode plates disposed so as to sandwich the optical axis AX1 from the same direction (X-axis direction) as the row of openings 28a. It is configured. This stage feedback deflector 40, can be finely adjusting the irradiation position of the electron beam EB ₃ in the X-axis direction. In the present embodiment, the stage feedback deflector 40 is configured by an electrostatic deflector, but is not limited to this configuration. For example, the stage feedback deflector 40 may be composed of an electromagnetic type deflector that arranges at least a pair of coils so as to sandwich the optical axis and deflects a beam by a magnetic field generated by passing a current through these coils.

The components of the electron gun 22 and the optical system 23 described so far are controlled by the controller 64 based on instructions from the main controller 50 (see FIG. 12).

A pair of backscattered electron detectors 42 _x1 and 42 _x2 are provided below the fourth electromagnetic lens 38D on both sides in the X-axis direction. Although not shown in FIG. 4, actually, a pair of backscattered electron detectors 42 _y1 and 42 _y2 are provided on both sides in the Y-axis direction below the fourth electromagnetic lens 38D. (See FIG. 12). Each of these backscattered electron detection devices is constituted by, for example, a semiconductor detector, and detects a backscattered electron detected by a reflected component generated from a detection target mark such as an alignment mark or a reference mark on the wafer, here a backscattered electron. Is sent to the signal processing device 62 (see FIG. 12). The signal processing device 62 performs signal processing after amplifying the detection signals of the plurality of backscattered electron detection devices 42 by an amplifier (not shown), and sends the processing result to the main control device 50 (see FIG. 12).

When all 5000 beams of the optical system column (multi-beam optical system) 20 are turned on (a state in which an electron beam is irradiated on the wafer), the beams are, for example, in a parallelogram region (exposure region) of 100 μm × 50 nm. A rectangular spot of an electron beam smaller than the resolution limit of the ultraviolet light exposure apparatus is simultaneously formed at 5000 points set in a positional relationship corresponding to the arrangement of 5000 openings 28a of the shaping aperture plate 28. The size of each spot is, for example, the dimension in the X-axis direction is γ · p = 20 nm and the dimension in the Y-axis direction is 4γp / 7 = 11.43 nm. γ is the magnification of the optical system column 20. If p = 1 μm, γ is 1/50.

In the present embodiment, one optical system unit 70 is configured by the electron gun 22, the optical system 23, the backscattered electron detection device 42, the control unit 64, and the signal processing device 62 in the column cell 21. The same number (100) of optical system units 70 as the multi-beam optical system (optical system column) 20 are provided (see FIG. 12).

The 100 multi-beam optical systems 20 correspond to, for example, approximately 100 shot areas formed on a 300 mm wafer (or formed from a shot map according to a shot map), for example, approximately 1: 1. In the electron beam exposure apparatus 100, each of the 100 multi-beam optical systems 20 generates a large number (5000) of, for example, 20 nm × 11.43 nm rectangular electron beam spots that can be turned on / off. It arrange | positions in the above-mentioned parallelogram area | region (exposure area | region). By scanning the wafer W in a predetermined scanning direction (Y-axis direction) with respect to this exposure area and turning on and off while deflecting the rectangular spots of the many electron beams, 100 shot areas on the wafer Are exposed to form a pattern. Therefore, in the case of a 300 mm wafer, it is sufficient that the movement stroke of the wafer at the time of exposure is several tens of mm, for example, 50 mm even with some margin.

Although the explanation has been made before and after, here is the basis for determining the pitch px of the openings 28a in the X-axis direction and the distance between the closest openings 28a (the pitch in the direction inclined by a predetermined angle with respect to the X-axis) as described above. explain.

As shown in FIG. 6 (A), consider two linear currents whose distance is R. The direction from the mask to the wafer is the + z direction, and the direction of the second linear current with respect to the first linear current is the + x direction. First, considering the electric field E (R) created at one point P on the second linear current by the first linear current, the following equation (1) is obtained.

E (R) = σ / (4πε ₀ R) ∫sinθdθ (1)
Here, σ is the linear density of charge of the first linear current, and ε ₀ is the dielectric constant of vacuum. Further, θ is an angle formed with the z-axis when P is viewed from the charge of the first linear current, and the range of θ is 0 ≦ θ ≦ π when considering to infinity.

The important point is that the electric field E (R) is inversely proportional to the first order of the inter-beam distance R, as is clear from the equation (1), and the force exerted on the electrons on the point P by the electric field E (R). The size F of
F = e E (R)
Therefore, F is also inversely proportional to R (where e is the charge of electrons).

As a result of the electrons flying from the mask to the wafer receiving a force F in the x direction, how much the electrons constituting the second linear current are displaced in the x direction on the wafer surface, that is, calculating the positional deviation Δx,
Equation of motion F = e E (R) = m (d ² x / dt ² )
Thus, the following equation (2) is obtained.

Δx = eE (R) / (2m) · t ² (2)
Here, m is the mass of electrons, and t is the flight time of electrons.

The important point is that since the electric field E (R) is inversely proportional to the first order of the inter-beam distance R, the positional deviation Δx is also inversely proportional to the first order of the inter-beam distance R as shown in FIG. is there.

Therefore, it is considered that the positional deviation Δx caused by the inter-beam interaction is qualitatively inversely proportional to the distance between the openings 28a of the blanking aperture array 29 (more precisely, the beam shaping aperture plate 28).

Therefore, in the present embodiment, the ON state due to the Coulomb force acting between the plurality of beams (corresponding to the first linear current and the second linear current) that respectively pass through the plurality of openings 28a of the blanking aperture array 29. Of the plurality of apertures 28a on the blanking aperture array 29 so that the irradiation position shift (corresponding to Δx) on the target surface of the beam (corresponding to the first linear current) of the beam is equal to or less than an allowable value. Arrangement is defined. In the present embodiment, the arrangement (arrangement) of the plurality of openings 28a on the blanking aperture array 29 is based on the distance between the plurality of beams (corresponding to R described above) and the Coulomb force acting between the plurality of beams. The relationship between the positional deviation of the beam in the ON state (corresponding to the above-mentioned Δx), that is, the positional deviation Δx caused by the above-mentioned beam-to-beam interaction is qualitatively determined. A relationship inversely proportional to the distance between the apertures 28a of the aperture plate 28) (relation represented by the graph in FIG. 6B), and using another expression, can be obtained by changing the distance between the beams. It is determined in consideration of the positional information of the beam in the on-state caused by the Coulomb force acting on. For example, the plurality of openings 28a is 2p or more, which is twice the length p in the X-axis direction of the openings, that is, the above-described complementary lithography is performed using the electron beam exposure apparatus 100 according to the present embodiment, and line and The pitch is set to 2p or more of the line portion to be cut when the space pattern is cut.

However, in consideration of the ability to adjust the irradiation position of the beam to be turned on via the control unit 64 by the main controller 50, the above-mentioned allowable value is determined and the positional deviation of the beam in the on state (corresponding to the above Δx) ) In the X-axis direction of the plurality of openings 28a of the beam shaping aperture plate 28 and the distance between the closest openings 28a (pitch in a direction inclined by a predetermined angle with respect to the X-axis) ) May be defined. For example, the pitch in the X axis direction may be determined in consideration of the ability of the stage feedback deflector 40 to adjust the irradiation position of the electron beam EB ₃ in the X axis direction.

Next, the configuration of the stage device 83 will be described. FIG. 7 shows a perspective view of a state in which a wafer shuttle (hereinafter abbreviated as shuttle) 10 is mounted on the coarse / fine movement stage 85 of the stage device 83. FIG. 8 is a perspective view of the coarse / fine movement stage 85 shown in FIG. 7 in a state in which the shuttle 10 is detached (removed).

The surface plate 84 provided in the stage device 83 is actually installed on the bottom wall of the vacuum chamber 80 that partitions the exposure chamber 81. As shown in FIGS. 7 and 8, the coarse / fine movement stage 85 includes a coarse movement stage 85a and a fine movement stage 85b. The coarse movement stage 85a is disposed at a predetermined interval in the Y-axis direction, includes a pair of quadrangular columnar portions extending in the X-axis direction, and is movable on the surface plate 84 in the X-axis direction with a predetermined stroke, for example, 50 mm. is there. The fine movement stage 85b can move with respect to the coarse movement stage 85a in the Y-axis direction with a predetermined stroke, for example, 50 mm, and the remaining five degrees of freedom, that is, the X-axis direction, the Z-axis direction, and the rotation directions around the X-axis ( It is movable in a shorter stroke than the Y-axis direction in the θx direction), the rotation direction around the Y axis (θy direction), and the rotation direction around the Z axis (θz direction). Although not shown, the pair of square columnar portions of the coarse movement stage 85a are actually connected by a connection member (not shown) in a state that does not prevent the movement of the fine movement stage 85b in the Y-axis direction. It is integrated.

The coarse movement stage 85a is driven by a coarse movement stage drive system 86 (see FIG. 12) with a predetermined stroke (for example, 50 mm) in the X axis direction (see the long arrow in the X axis direction in FIG. 10). The coarse movement stage drive system 86 is constituted by a uniaxial drive mechanism that does not cause magnetic flux leakage in this embodiment, for example, a feed screw mechanism using a ball screw. The coarse movement stage drive system 86 is arranged between one square columnar portion of the pair of square columnar portions of the coarse movement stage and the surface plate 84. For example, a screw shaft is attached to the surface plate 84, and a ball (nut) is attached to one square columnar portion. In addition, the structure which attaches a ball | bowl to the surface plate 84 and attaches a screw shaft to one square pillar-shaped part may be sufficient.

Further, of the pair of quadrangular columnar portions of the coarse movement stage 85a, the other quadrangular columnar portion is configured to move along a guide surface (not shown) provided on the surface plate 84.

The screw shaft of the ball screw is driven to rotate by a stepping motor. Or you may comprise the coarse motion stage drive system 86 by the uniaxial drive mechanism provided with the ultrasonic motor as a drive source. In any case, the magnetic field fluctuation caused by the magnetic flux leakage does not affect the positioning of the electron beam. The coarse movement stage drive system 86 is controlled by the main controller 50 (see FIG. 12).

As shown in the enlarged perspective view of FIG. 9, the fine movement stage 85 b is made of a member having an XZ cross-sectional rectangular frame shape penetrating in the Y-axis direction, and is placed on the surface plate 84 in the XY plane by the weight cancellation device 87. It is supported movably. A plurality of reinforcing ribs are provided on the outer surface of the side wall of fine movement stage 85b.

Inside the hollow portion of fine movement stage 85b, there are provided a yoke 88a having a rectangular frame shape in the XZ section and extending in the Y-axis direction, and a pair of magnet units 88b fixed to the upper and lower opposing surfaces of yoke 88a. 88a and a pair of magnet units 88b constitute a mover 88 of a motor that drives fine movement stage 85b.

FIG. 10 shows a state in which a magnetic shield member (to be described later) indicated by fine movement stage 85b and reference numeral 91 is removed from FIG. As shown in FIG. 10, corresponding to the mover 88, a stator 89 made of a coil unit is installed between a pair of square column portions of the coarse movement stage 85 a. With the stator 89 and the above-described mover 88, the mover 88 can be moved with respect to the stator 89 by a predetermined stroke, for example, 50 mm in the Y-axis direction, as indicated by arrows in each direction in FIG. Further, a closed magnetic field type and moving magnet type motor 90 that can be finely driven in the X axis direction, the Z axis direction, the θx direction, the θy direction, and the θz direction is configured. In the present embodiment, a fine movement stage drive system that drives the fine movement stage 85b in the direction of six degrees of freedom by the motor 90 is configured. Hereinafter, the fine movement stage drive system is referred to as a fine movement stage drive system 90 using the same reference numerals as those of the motor. Fine movement stage drive system 90 is controlled by main controller 50 (see FIG. 12).

Between the pair of quadrangular column portions of the coarse movement stage 85a, as shown in FIGS. 7 and 8, for example, the XZ cross-section reverse U is further applied while covering the upper surface of the motor 90 and both side surfaces in the X-axis direction. A letter-shaped magnetic shield member 91 is installed. That is, the magnetic shield member 91 is formed so as to extend in a direction (Y-axis direction) intersecting with the direction in which the quadrangular prism portion extends, and on the upper surface of the motor 90 in a non-contact manner and on the side surface of the motor 90. And a side portion that faces each other in a non-contact manner. The magnetic shield member 91 is inserted into the hollow portion of the fine movement stage 85b, and the lower surface of both end portions in the longitudinal direction (Y-axis direction) is the upper surface of the pair of quadrangular column portions of the coarse movement stage 85a. It is fixed to. Further, of the side surfaces of the magnetic shield member 91, the surfaces other than the lower surfaces of the both end portions are opposed to the bottom wall surface (lower surface) of the inner wall surface of the fine movement stage 85b without contact. That is, the magnetic shield member 91 is inserted into the hollow portion of the fine movement stage 85b in a state where the movement of the mover 88 relative to the stator 89 is not hindered.

As the magnetic shield member 91, a laminated magnetic shield member composed of a plurality of layers of magnetic material films laminated with a predetermined gap (space) is used. In addition, a magnetic shield member having a configuration in which films of two kinds of materials having different magnetic permeability are alternately laminated may be used. Since the magnetic shield member 91 covers the upper surface and the side surface of the motor 90 over the entire length of the moving stroke of the mover 88 and is fixed to the coarse movement stage 85a, the fine movement stage 85b and the coarse movement stage 85a. Leakage of magnetic flux upward (on the electron beam optical system side) can be prevented almost certainly over the entire moving range.

As shown in FIG. 9, the weight canceling device 87 includes a metal bellows type air spring (hereinafter abbreviated as “air spring”) 87a whose upper end is connected to the lower surface of the fine movement stage 85b, and a lower end of the air spring 87a. And a base slider 87b made of a connected flat plate member. The base slider 87b is provided with a bearing portion (not shown) that blows air inside the air spring 87a to the upper surface of the surface plate 84, and the bearing surface of the pressurized air ejected from the bearing portion and the upper surface of the surface plate 84 are provided. The self-weight of the weight canceling device 87, fine movement stage 85b and mover 88 (including the shuttle 10 when the shuttle 10 is mounted on the coarse / fine movement stage 85) is supported by the static pressure (pressure in the gap). Has been. Note that compressed air is supplied to the air spring 87a via a pipe (not shown) connected to the fine movement stage 85b. The base slider 87b is supported in a non-contact manner on the surface plate 84 via a kind of differential exhaust type aerostatic bearing, and air blown from the bearing portion toward the surface plate 84 is surrounded by (exposure chamber). To prevent leakage.

Here, a structure for detachably attaching the shuttle 10 to the coarse / fine movement stage 85, more precisely, to the fine movement stage 85b will be described.

As shown in FIG. 8, three triangular pyramid groove members 12 are provided on the upper surface of fine movement stage 85b. For example, the triangular pyramidal groove member 12 is provided at the positions of three apexes of a regular triangle in plan view. The triangular pyramid groove member 12 can be engaged with a sphere or hemisphere provided in the shuttle 10 described later, and constitutes a kinematic coupling together with the sphere or hemisphere. FIG. 8 shows a triangular pyramid groove member 12 such as a petal composed of three plate members. The triangular pyramid groove member 12 is a triangular pyramid that makes point contact with a sphere or a hemisphere, respectively. Since it has the same role as the groove, it is called a triangular pyramid groove member. Therefore, a single member in which a triangular pyramid groove is formed may be used instead of the triangular pyramid groove member 12.

In this embodiment, three spheres or hemispheres (balls in the present embodiment) 14 are provided in the shuttle 10 corresponding to the three triangular pyramid groove members 12 as shown in FIG. The shuttle 10 is formed in a hexagonal shape in which each vertex of an equilateral triangle is cut off in plan view. More specifically, the shuttle 10 has notches 10a, 10b, and 10c formed at the center of each of the three oblique sides in plan view, and covers the notches 10a, 10b, and 10c from the outside. The leaf springs 16 are respectively attached. Balls 14 are fixed to the center of each leaf spring 16 in the longitudinal direction. In a state before being engaged with the triangular pyramid groove member 12, each ball 14, when subjected to an external force, has a radial direction centered on the center of the shuttle 10 (substantially coincides with the center of the wafer W shown in FIG. 7). Only move to a minute.

After moving the shuttle 10 to a position where the three balls 14 substantially oppose the three triangular pyramidal groove members 12 above the fine movement stage 85b, respectively, the shuttle 10 is moved down so that each of the three balls 14 becomes The three triangular pyramid groove members 12 are individually engaged, and the shuttle 10 is mounted on the fine movement stage 85b. Even when the position of the shuttle 10 with respect to the fine movement stage 85b is deviated from the desired position at the time of mounting, when the ball 14 engages with the triangular pyramid groove member 12, the external force is received from the triangular pyramid groove member 12, and the aforementioned Move in the radial direction. As a result, the three balls 14 always engage with the corresponding triangular pyramidal groove members 12 in the same state. On the other hand, the shuttle 10 can be easily detached (detached) from the fine movement stage 85b simply by moving the shuttle 10 upward and releasing the engagement between the ball 14 and the triangular pyramid groove member 12. That is, in this embodiment, a kinematic coupling is constituted by the set of three balls 14 and the triangular pyramid groove member 12, and the kinematic coupling always keeps the mounting state of the shuttle 10 to the fine movement stage 85b substantially the same. It can be set to the state. Therefore, no matter how many times it is removed, the shuttle 10 and the fine movement of the shuttle 10 can be moved by simply mounting the shuttle 10 on the fine movement stage 85b via the kinematic coupling (the set of three pairs of balls 14 and the triangular pyramid groove member 12). A certain positional relationship with the stage 85b can be reproduced.

On the upper surface of the shuttle 10, for example, as shown in FIG. 7, a circular concave portion having a diameter slightly larger than that of the wafer W is formed at the center, and an electrostatic chuck (not shown) is provided in the concave portion. The wafer W is electrostatically attracted and held by the chuck. In the holding state of the wafer W, the surface of the wafer W is substantially flush with the upper surface of the shuttle 10.

Next, a position measurement system that measures position information of the coarse / fine movement stage 85 will be described. This position measurement system includes the first measurement system 52 that measures the position information of the shuttle 10 and the position information of the fine movement stage 85b in a state where the shuttle 10 is mounted on the fine movement stage 85b via the kinematic coupling described above. And a second measurement system 54 that directly measures (see FIG. 12).

First, the first measurement system 52 will be described. Grating plates 72a, 72b, and 72c are provided in the vicinity of the three sides of the shuttle 10 except for the three oblique sides, as shown in FIG. Each of the grating plates 72a, 72b, and 72c has a two-dimensional shape in which a radial direction centered on the center of the shuttle 10 (in the present embodiment, coincides with the center of a circular concave portion) and a direction orthogonal thereto are each a periodic direction. Each lattice is formed. For example, the grating plate 72a is formed with a two-dimensional lattice having a periodic direction in the Y-axis direction and the X-axis direction. The grating plate 72b is formed with a two-dimensional grating having a direction that is −120 degrees with respect to the Y axis with respect to the center of the shuttle 10 (hereinafter referred to as α direction) and a direction perpendicular thereto as a periodic direction. The grating plate 72c is formed with a two-dimensional grating having a direction that forms +120 degrees with respect to the Y axis with respect to the center of the shuttle 10 (hereinafter referred to as β direction) and a direction perpendicular thereto as a periodic direction. As the two-dimensional grating, a reflection type diffraction grating having a pitch of, for example, 1 μm is used in each periodic direction.

As shown in FIG. 11A, on the lower surface (the surface on the −Z side) of the metrology frame 94, there are three heads at positions that can individually face the three grating plates 72a, 72b, 72c. The parts 74a, 74b, and 74c are fixed. Each of the three head portions 74a, 74b, and 74c is provided with a four-axis encoder head having a measurement axis indicated by four arrows in FIG. 11B.

More specifically, the head portion 74a includes a first head housed in the same housing and having a measurement direction in the X-axis direction and the Z-axis direction, and a measurement direction in the Y-axis direction and the Z-axis direction. And a second head. The first head (more precisely, the irradiation point on the grating plate 72a of the measurement beam emitted by the first head) and the second head (more precisely, the irradiation of the measurement beam emitted by the second head on the grating plate 72a). Are arranged on a straight line parallel to the same X axis. The first head and the second head of the head portion 74a are each a biaxial linear encoder that measures position information of the shuttle 10 in the X-axis direction and the Z-axis direction, and the Y-axis direction and the Z-axis direction using the grating plate 72a. A two-axis linear encoder that measures the position information is configured.

The remaining head portions 74b and 74c are configured in the same manner as the head portion 74a including the first head and the second head, although the directions with respect to the respective metrology frames 94 are different (measurement directions in the XY plane are different). ing. The first head and the second head of the head part 74b each use a grating plate 72b to measure the position information in the direction orthogonal to the α direction of the shuttle 10 in the XY plane and the position information in the Z-axis direction, and A two-axis linear encoder that measures position information in the α direction and the Z-axis direction is configured. The first head and the second head of the head portion 74c each use a grating plate 72c, and a biaxial linear encoder that measures position information in a direction orthogonal to the β direction of the shuttle 10 in the XY plane and in the Z axis direction, and A two-axis linear encoder that measures position information in the β direction and the Z-axis direction is configured.

As each of the 1st head and 2nd head which each head part 74a, 74b, 74c has, the encoder head of the structure similar to the displacement measurement sensor head disclosed by the US Patent 7,561,280, for example is used. Can be used.

An encoder system is configured by the three head portions 74a, 74b, and 74c that measure the position information of the shuttle 10 using the above-described three sets, that is, a total of six biaxial encoders, that is, three grating plates 72a, 72b, and 72c, respectively. The first measurement system 52 (see FIG. 12) is configured by this encoder system. Position information measured by the first measurement system 52 is supplied to the main controller 50.

In the first measurement system 52, since the three head portions 74a, 74b, and 74c each have four measurement degrees of freedom (measurement axes), a total of 12 degrees of freedom can be measured. That is, in the three-dimensional space, since the maximum degree of freedom is 6, redundant measurement is actually performed for each of the 6 degrees of freedom directions, and two pieces of position information are obtained.

Therefore, based on the position information measured by the first measurement system 52, the main controller 50 uses the average value of the two pieces of position information for each degree of freedom as the measurement result in each direction. Thereby, it becomes possible to obtain | require the positional information on the shuttle 10 and the fine movement stage 85b with high precision about all the directions of 6 degrees of freedom by the averaging effect.

Next, the second measurement system 54 will be described. The second measurement system 54 can measure position information in the direction of 6 degrees of freedom of the fine movement stage 85b regardless of whether or not the shuttle 10 is mounted on the fine movement stage 85b. For example, the second measurement system 54 irradiates a reflection surface provided on the outer surface of the side wall of the fine movement stage 85b, receives the reflected light, and measures position information of the fine movement stage 85b in the 6-degree-of-freedom direction. Can be configured by the system. Each interferometer of the interferometer system may be suspended and supported on the metrology frame 94 via a support member (not shown), or may be fixed to the surface plate 84. Since the second measurement system 54 is provided in the exposure chamber 81 (in the vacuum space), there is no possibility of a decrease in measurement accuracy due to air fluctuation. In the present embodiment, the second measurement system 54 mainly determines the position and orientation of the fine movement stage 85b when the shuttle 10 is not mounted on the fine movement stage 85b (including when the wafer is not exposed). Since it is used to maintain a desired state, the measurement accuracy may be lower than that of the first measurement system 52. The position information measured by the second measurement system 54 is supplied to the main controller 50 (see FIG. 12). In addition, you may comprise a 2nd measurement system not only by an interferometer system but by an encoder system or the combination of an encoder system and an interferometer system. In the latter case, position information in the direction of three degrees of freedom in the XY plane of 85b of the fine movement stage may be measured by the encoder system, and position information in the remaining three degrees of freedom direction may be measured by the interferometer system.

Measurement information by the first measurement system 52 and the second measurement system 54 is sent to the main control device 50, and the main control device 50 is based on measurement information by at least one of the first measurement system 52 and the second measurement system 54. The coarse / fine movement stage 85 is controlled. Further, the main controller 50 uses the measurement information from the first measurement system 52 to control the stage feedback deflector 40 of each of the plurality of multi-beam optical systems 20 included in the electron beam irradiation device 92 of the exposure system 82 as necessary. Also used.

FIG. 12 is a block diagram showing the input / output relationship of the main controller 50 that mainly constitutes the control system of the electron beam exposure apparatus 100. Main controller 50 includes a microcomputer and the like, and comprehensively controls each component of electron beam exposure apparatus 100 including each component shown in FIG.

In the present embodiment, the flow of processing for the wafer is as follows.

First, the pre-exposure the electron beam resist is coated wafer (for convenience, referred to as wafer W ₁₎ is, within the measurement chamber (not shown), the shuttle (for convenience, referred to as the shuttle 10 ₁₎ to be placed, It is adsorbed by the shuttle 10 ₁ of the electrostatic chuck. Then, with respect to the wafer W _1, schematic (rough) position measurement with respect to the shuttle 10 _1, the pre-measurement, such as flatness measurement, performed by the measurement chamber of the measurement system (not shown).

Then, the shuttle 10 ₁ holding the wafer W ₁ is, by a conveying system (not shown), is transported into the exposure chamber 81 through the load lock chamber provided in the chamber 80, the transport system in the exposure chamber 81 (not It is conveyed to a predetermined first standby position (for example, one of a plurality of storage shelves of a shuttle stocker (not shown)).

Next, in the exposure chamber 81, a shuttle exchange operation, that is, a wafer exchange operation integrated with the shuttle is performed as follows.

Wafer exposed during loading of the shuttle 10 ₁ has been performed (for convenience, the wafer W is ₀ hereinafter) when the exposure is completed, the transfer system, the shuttle to hold the exposed wafer W ₀ (for convenience, the shuttle 10 ₀ Is removed from fine movement stage 85b and conveyed to a predetermined second standby position. The second standby position is assumed to be another one of the plurality of storage shelves of the shuttle stocker described above.

In advance to the shuttle 10 ₀ is removed from the fine movement stage 85b, based on the measurement information of the second measurement system 54 (see FIG. 12), in directions of six degrees of freedom position of the fine moving stage 85b, the feedback control of the posture, initiated by the main controller 50, then based on the first measurement information of the measurement system 52 (see FIG. 12), until the position control of the shuttle 10 ₁ integral with the fine movement stage 85b is started, the fine movement stage 85b The position and orientation in the 6-degree-of-freedom direction are maintained in a predetermined reference state.

Then, the transport system in the exposure chamber 81, the shuttle 10 ₁ is transported upward in the coarse and fine movement stage 85 is mounted on the fine movement stage 85b. At this time, as described above, directions of six degrees of freedom position of the fine moving stage 85b, since the posture is maintained at the reference state, the shuttle 10 _1, only attached to the fine movement stage 85b via the kinematic coupling, electronic positional relationship of the beam irradiation device 92 (the electron beam optics) and the shuttle 10 ₁ has a desired positional relationship. Then, the schematic position measurement with respect to the shuttle 10 ₁ of the wafer W ₁ made in advance results in consideration of the position of 85b of fine movement stage by the fine adjustment, on the fine moving stage 85b the shuttle 10 ₁ attached to the each of the 100 shot areas formed on the wafer W ₁ corresponding to at least each one of the alignment marks formed in the scribe line (street line), reliably irradiated with the electron beam from the electron beam optics It becomes possible. Therefore, reflected electrons from at least one alignment mark are detected by at least one of the reflected electron detectors 42 _x1 , 42 _x2 , 42 _y1 , and 42 _y2 , and all-point alignment measurement of the wafer W ₁ is performed. based on the results of the point alignment measurement, the plurality of shot areas on the wafer W _1, exposure to an electron beam irradiation device 92 is started. For example, in the case of complementary lithography, a plurality of beams (electron beams) emitted from each multi-beam optical system 20 are used to form a cut pattern for a line and space pattern formed on the wafer W and having a periodic direction in the X-axis direction. When forming, the irradiation timing (ON / OFF) of each beam is controlled while scanning the wafer W (fine movement stage 85b) in the Y-axis direction.

In parallel with all points alignment measurement and exposure described above, it is unloaded and conveyed to the above-mentioned measurement chamber from the shuttle 10 ₀ of the exposure chamber 81 in a second standby position is performed. Detailed description thereof will be omitted.

Within the exposure chamber 81, while the exposure of the wafer W ₁ is being carried out, the shuttle 10 holding the pre-measurement was the next to be exposed ends wafer is carried into the exposure chamber, waiting in the first waiting position described above To do. When the exposure of the wafer W ₁ is completed, it is performed exchanging operation of the wafer integral with the above-mentioned shuttle, following the same procedure as described above is repeated.

Here, beam irradiation control in actual complementary lithography will be described.

In complementary lithography, if all the beams in each optical system column 20 are turned on simultaneously, a plurality of beams (cut pattern beams) MB on the L / S pattern LSP are shown in FIG. It is irradiated with such a positional relationship. From FIG. 13 (A), it can be seen that any beam MB is not affected by the Coulomb force (Coulomb interaction) with other beams MB and is accurately irradiated onto the line pattern.

However, in actual complementary lithography, there is a case where, for example, a predetermined number of line patterns are continuously cut every other line or every other line pattern at the same position in the Y-axis direction. FIG. 13B shows a state in which cut patterns MB ′ are formed at the same Y position on a predetermined number of continuous line patterns as an example. In such a case, the wafer W (fine movement stage 85b) is scanned in the Y-axis direction, and the beam is irradiated at the timing when the cutting point on each line pattern to be cut is positioned at the beam irradiation position. In addition, the irradiation timing (on / off) of each beam is controlled.

Here, as an example, as shown in FIG. 13B, a series of flows when the cut pattern MB ′ is formed at the same Y position on a predetermined number of continuous line patterns will be described.

In this case, first, the cutting point on the L / S pattern LSP on the wafer W is moved to the blanking aperture while moving the wafer W (fine movement stage 85b) in the + Y direction indicated by the white arrow in FIG. When the position of the opening 28a in the first row of the array 29 (beam shaping aperture plate 28) is reached, the beam MB passing through the opening 28a in the first row is irradiated onto the wafer. As a result, the L / S pattern LSP on the wafer W has four line patterns ((1 + 5n) columns (n = 0, 1, 2,...) From the first column line pattern located closest to the + X side. ...) is formed on the line pattern).

Then, when the wafer W further moves a predetermined distance in the + Y direction indicated by the white arrow, as shown in FIG. 14B, in the (1 + 5n) th column (n = 0, 1, 2,...). The cutting point on the L / S pattern LSP on which the cut pattern MB ′ is formed reaches the position of the opening 28a in the second row of the blanking aperture array 29 (beam shaping aperture plate 28), and the second row The beam MB passing through the opening 28a is irradiated onto the wafer. As a result, every fourth line pattern (line pattern of (2 + 5n) th column (n = 0, 1, 2,...)) From the line pattern of the second column is included in the L / S pattern LSP on the wafer W. A cut pattern is formed on top.

When the wafer W further moves a predetermined distance in the + Y direction indicated by the white arrow, as shown in FIG. 15A, the (1 + 5n) th column and the (2 + 5n) th column (n = 0, 1, 2), the cutting point on the L / S pattern LSP on which the cut pattern MB ′ is formed reaches the position of the opening 28a in the third row of the blanking aperture array 29 (beam shaping aperture plate 28). The beam MB passing through the opening 28a in the third row is irradiated onto the wafer. As a result, every fourth line pattern from the third line pattern (the (3 + 5n) th line (n = 0, 1, 2,...) Line pattern) is applied to the L / S pattern LSP on the wafer W. A cut pattern is formed on top.

When the wafer W further moves a predetermined distance in the + Y direction indicated by the white arrow, as shown in FIG. 15B, the (1 + 5n) th row, the (2 + 5n) th row, and the (3 + 5n) th row ( The cutting point on the L / S pattern LSP in which the cut pattern MB ′ is formed at n = 0, 1, 2,...) is the opening in the fourth row of the blanking aperture array 29 (beam shaping aperture plate 28). The beam MB reaching the position 28a and passing through the opening 28a in the fourth row is irradiated onto the wafer. As a result, every fourth line pattern from the fourth line pattern (the (4 + 5n) th line (n = 0, 1, 2,...) Line pattern) is included in the L / S pattern LSP on the wafer W. A cut pattern is formed on top.

Then, when the wafer W further moves a predetermined distance in the + Y direction indicated by the white arrow, as shown in FIG. 16, the (1 + 5n) th column, the (2 + 5n) th column, the (3 + 5n) th column and the (4 + 5n) th column. ) The cutting point on the L / S pattern LSP in which the cut pattern MB ′ is formed in the column (n = 0, 1, 2,...) Is the fifth row of the blanking aperture array 29 (beam shaping aperture plate 28). A beam MB that reaches the position of the eye opening 28a and passes through the opening 28a in the fifth row is irradiated onto the wafer. As a result, every fourth line pattern from the fifth column line pattern (the (5 + 5n) th column (n = 0, 1, 2,...) Line pattern) is included in the L / S pattern LSP on the wafer W. A cut pattern is formed on top. As a result, as shown in FIG. 13B, cut patterns MB ′ are formed at the same Y position on a predetermined number of continuous line patterns.

Here, in any of FIG. 14A, FIG. 14B, FIG. 15A, FIG. 15B, and FIG. 16, on every four line patterns of the L / S pattern LSP of the wafer W. In addition, since the beams are irradiated at a pitch of 5p, any beam (cut pattern) MB is not affected by the Coulomb force (Coulomb interaction) between the adjacent beams MB and the irradiation position is not shifted. Therefore, it is not necessary to correct the irradiation position deviation in the X-axis direction (the periodic direction of the line-and-space pattern LSP that is the target of line pattern cutting in complementary lithography).

As is apparent from the above description, in this embodiment, the shuttle 10 that holds the wafer W, the coarse / fine movement stage 85 on which the shuttle 10 is mounted, the fine movement stage drive system 90, and the coarse movement stage drive system 86, Thus, a stage that holds and moves the target wafer W is configured.

As described above, according to the electron beam exposure apparatus 100 according to the present embodiment, during actual wafer exposure, the main control apparatus 50 performs a shuttle for holding the wafer with respect to the electron beam irradiation apparatus 92 (electron beam optical system). Scanning (moving) in the Y-axis direction of fine movement stage 85 b to which 10 is mounted is controlled via fine movement stage drive system 90 and coarse movement stage drive system 86. In parallel with this, the main controller 50, for each of m (for example, 100) optical column (multi-beam optical system) 20 of the electron beam irradiation device 92, n (for example, beam shaping aperture plates 28). The irradiation state (on state and off state) of the n beams respectively passing through the (5000) openings 28a is changed for each opening 28a, and in particular, the irradiation position in the Y-axis direction of the beam to be turned on is changed. The adjustment is performed by individually controlling the irradiation timings of the plurality of beams irradiated to the wafer from each of the multi-beam optical systems 20. Thereby, for example, a desired line of a fine line-and-space pattern in which the X-axis direction is formed in advance in each of, for example, 100 shot regions on the wafer by double patterning using an ArF immersion exposure apparatus or the like. A cut pattern can be formed at a desired upper position (see FIG. 13B), and exposure with high accuracy and high throughput is possible. In the present embodiment, the Coulomb acting between a plurality of beams (corresponding to the first linear current and the second linear current described above) respectively passing through the plurality of openings 28a of the blanking aperture array 29 of each multi-beam optical system. A plurality of beams on the blanking aperture array 29 are set such that the irradiation position shift (corresponding to Δx above) on the wafer surface of the on-state beam (corresponding to the first linear current described above) due to force is less than an allowable value. The arrangement of the openings 28a is determined. In the present embodiment, the arrangement (arrangement) of the plurality of openings 28a on the blanking aperture array 29 is such that the positional deviation Δx caused by the above-mentioned beam-to-beam interaction is qualitatively determined more accurately. Is determined in consideration of the relationship inversely proportional to the distance between the openings 28a of the beam shaping aperture plate 28) (the relationship represented by the graph in FIG. 6B). In other words, the arrangement (arrangement) of the plurality of apertures 28a on the blanking aperture array 29 is obtained by changing the distance between the beams, and the position of the beam in the on state caused by the Coulomb force acting between the beams. It is determined in consideration of information.

Therefore, when performing the above-described complementary lithography using the electron beam exposure apparatus 100 according to the present embodiment and cutting the line and space pattern, blanking is performed in each multi-beam optical system of the electron beam irradiation apparatus 92. Even if the beam passing through any one of the plurality of apertures 28a on the aperture array 29 is turned on, in other words, regardless of the combination of the beams that are turned on, on the wafer For example, it is possible to form a cut pattern at a desired X position on a desired line in a fine line-and-space pattern having a periodic direction in the X-axis direction formed in each of 100 shot regions. Become.

The arrangement of the openings 28a on the beam shaping aperture plate 28 described in the above embodiment is only an example. For example, you may employ | adopt arrangement | positioning of the opening 28a corresponding to the beam MB shown by FIG. 17 (A) or FIG. 17 (B). 17A and 17B show a state where the beam MB that has passed through the opening 28a on the beam shaping aperture plate 28 is irradiated onto the L / S pattern. When the arrangement of the openings 28a corresponding to the arrangement of the beams MB in FIG. 17A is adopted, the area of the arrangement area of the openings on the beam shaping aperture plate 28 is set to the above embodiment (FIG. 5A and FIG. 5 (B)). The arrangement of the beams MB ₁ and MB ₂ in FIG. 17B is an example of arrangement when each opening 28 has a backup opening corresponding to the beam MB ₂ . In this case, two beams MB ₁ and MB _{2 that} are vertically adjacent in FIG. 17B are not actually irradiated simultaneously.

The distance between adjacent openings 28a (or backup openings) on the beam shaping aperture plate 28 corresponding to the beam arrangement shown in FIGS. 17A and 17B is the X-axis direction of the openings 28a. The length of p is at least 2.5 p. Therefore, the irradiation position of the beam does not shift due to the Coulomb action with other beams.

In the above embodiment, the positional deviation in the X-axis direction from the irradiation position on the beam design is not corrected, or is reduced by controlling the stage feedback deflector 40. However, the positional deviation may be reduced as in the following two modifications.

<< Modification 1 >>
In the exposure apparatus and exposure method according to this modification, instead of the beam shaping aperture plate 28, as shown in FIG. 18A, the X axis direction of the opening 28a is arranged on both sides of the X axis direction of each opening 28a. A beam shaping aperture plate having a pair of auxiliary openings 28b separated by the same distance p as the length is used. The auxiliary opening 28b is an electron beam resist in which a dose amount (electron injection amount per unit area) of a beam that passes through the auxiliary opening 28b and is irradiated onto the wafer (target) is applied onto the wafer. For example, it has an area that is about 1/10 to 1/4 of the level to which the sensitivity is applied. The beam passing through each auxiliary opening 28b is turned on / off in the same manner as the beam passing through the opening 28a, and the beam passes through the opening 28a by changing the duty ratio of the on / off. The Coulomb action applied to the beam can be changed, thereby controlling the X shift amount of the beam. That is, the Coulomb effect is positively used for correction. In FIG. 18B, a beam is simultaneously irradiated from all the openings 28a and auxiliary openings 28b existing in a partial region of the beam shaping aperture plate 28 so as to overlap the L / S pattern formed on the wafer. The state is shown. From FIG. 18B, the irradiation position shift in the X-axis direction of a beam (referred to as a main beam for convenience) MB irradiated onto the wafer via each opening 28a is shifted onto the wafer via a pair of auxiliary openings 28b. Corrected by the Coulomb action between each of a pair of irradiated beams (referred to as sub-beams for convenience) SB and the main beam MB, each main beam MB is accurately irradiated onto the line pattern of the L / S pattern LSP. I understand.

<< Modification 2 >>
In the second modification, a beam shaping aperture plate 28B as shown in a plan view in FIG. 19A is used. In this beam shaping aperture plate 28B, as shown in FIG. 19B by enlarging the inside of the circle D in FIG. 19A, the length in the X-axis direction is p and the length in the Y-axis direction is p. Two aperture rows in which / 2 rectangular openings 128 are arranged in the X-axis direction at a pitch of 2p are formed apart by p / 2 in the Y-axis direction and shifted by p in the X-axis direction.

Here, in order to form a cut pattern as shown in FIG. 20A on the L / S pattern formed on the wafer using the beam shaping aperture plate 28B, a beam corresponding to the cut pattern is irradiated. Think about the case. In this case, as shown in FIG. 20B, a repulsive force acts between the beams passing through the openings 128 adjacent in the X-axis direction by a Coulomb action. Therefore, in FIG. 20B, the two beams shown in the upper row (beams that have passed through the corresponding openings 128) and the three beams shown in the lower row (each passed through the corresponding openings 128). It is expected that the irradiation positions of the beams at both ends of the beam) are shifted to the outside in the X-axis direction.

In this case, when the position of the opening 128 where the beam irradiation position shift is a problem can be identified, for example, as shown in FIG. 20C, the opening 128 where the beam irradiation position shift is expected. A dummy beam called a cut-off beam is irradiated through the opening 128 in the vicinity of. As a result, as shown in FIG. 20C, the two beams shown in the upper row and the beams at both ends of the lower row are connected to the beams passing through the openings located on both sides in the X-axis direction. A repulsive force acts between them, and the occurrence of an irradiation position shift in the X-axis direction is prevented. As described above, it is possible to correct the X shift amount of the beam by using the Coulomb force (Coulomb interaction) between the discarded cut beam and the beam whose X shift is to be corrected. In this case, a discarded cut beam may be provided so as to reduce pattern unevenness. In addition, when the non-uniform pattern is eliminated by setting the abandoned cut beam, there is an accompanying effect that the influence of the heat of irradiation on the wafer becomes more straightforward and correction becomes easier.

Here, in the case of the second modification, in consideration of the adjustment capability of the irradiation position shift with respect to the X-axis direction of the beam that is turned on using the discarded cut beam, the X-axis direction of the beam that is turned on is considered. The allowable value of the irradiation position deviation and the arrangement of the plurality of openings 128 of the beam shaping aperture plate 28B are determined.

In the above-described embodiment, the fine movement stage 85b that holds the wafer W via the shuttle 10 moves in the scanning direction (Y-axis direction) with respect to the electron beam irradiation device 92 (electron beam optical system), and uses the electron beam. Although the case where the scanning exposure of the wafer W is performed has been described, when the electron beam irradiation device 92 (electron beam optical system) is configured to be movable in a predetermined direction, for example, the Y-axis direction, the wafer is stationary. In this state, the wafer W may be scanned and exposed by the electron beam while moving the electron beam irradiation apparatus (electron beam optical system) in the Y-axis direction. Alternatively, the scanning exposure of the wafer W by the electron beam may be performed while moving the wafer W and the electron beam irradiation apparatus in opposite directions.

In the above embodiment, the case where the electron beam optical system included in the electron beam irradiation device 92 is configured by the m optical system columns 20 including the multi-beam optical system is described. The system may be a single column type multi-beam optical system.

As a multi-beam optical system according to the above-described embodiment, a method of turning on / off each beam is performed by generating a plurality of electron beams via a blanking aperture array having a plurality of apertures, and depending on a drawing pattern. A method of drawing the pattern on the sample surface by individually turning on / off the electron beam may be adopted. Further, instead of the blanking aperture array, a configuration using a surface emission type electron beam source having a plurality of electron emission portions for emitting a plurality of electron beams may be used.

In the above-described embodiment, the electron beam exposure apparatus of the type in which the wafer W is transported while being held by the shuttle 10 has been described. However, the present invention is not limited to this, and the stage (or table) for exposing the wafer W alone. A normal type in which exposure is performed by irradiating the wafer W with a beam from an electron beam irradiation apparatus (electron beam optical system) while moving the stage (or table) holding the wafer in the scanning direction. An electron beam exposure apparatus may be used. Even in such an electron beam exposure apparatus, as long as an electron beam optical system composed of a multi-beam optical system is provided, images of many apertures of the beam shaping aperture plate formed on the image surface of the multi-beam optical system described above. The method for correcting the distortion (irradiation position shift of each beam on the irradiation surface) can be preferably applied.

In the above embodiment, the case where the fine movement stage 85b is movable in the direction of 6 degrees of freedom with respect to the coarse movement stage 85a has been described. However, the present invention is not limited to this, and the fine movement stage can be moved only in the XY plane. May be. In this case, the first measurement system 52 and the second measurement system 54 that measure the position information of the fine movement stage may also be able to measure the position information related to the three degrees of freedom direction in the XY plane.

In the above embodiment, the case where the first measurement system 52 is configured by an encoder system has been described. However, the present invention is not limited thereto, and the first measurement system 52 may be configured by an interferometer system.

In the above-described embodiment, the electron beam irradiation device 92 is integrally supported with the metrology frame 94 and supported by being suspended from the top plate (ceiling wall) of the vacuum chamber via the three suspension support mechanisms 95a, 95b, and 95c. However, the present invention is not limited to this, and the electron beam irradiation device 92 may be supported by a floor-standing body. In the above embodiment, the case where the entire exposure system 82 is accommodated in the vacuum chamber 80 has been described. However, the present invention is not limited to this, and the column 93 of the electron beam irradiation apparatus 92 in the exposure system 82 is not limited thereto. A portion other than the lower end may be exposed to the outside of the vacuum chamber 80.

In addition, although the said embodiment demonstrated the case where a target was a wafer for semiconductor element manufacture, the electron beam exposure apparatus 100 which concerns on this embodiment forms a fine pattern on a glass substrate, and manufactures a mask. In particular, it can be suitably applied. For example, an exposure system for drawing a mask pattern on a rectangular glass plate or a silicon wafer, an exposure system for manufacturing an organic EL, a thin film magnetic head, an image sensor (CCD, etc.), a micromachine, a DNA chip, etc. Also good. In the above embodiment, an electron beam exposure apparatus using an electron beam as a charged particle beam has been described. However, the above embodiment can also be applied to an exposure apparatus using an ion beam or the like as a charged particle beam for exposure. .

In addition, the exposure technology that constitutes complementary lithography is not limited to the combination of the immersion exposure technology using an ArF light source and the charged particle beam exposure technology. For example, the line and space pattern may be changed to other types such as an ArF light source and KrF. You may form by the dry exposure technique using a light source.

As shown in FIG. 21, an electronic device (microdevice) such as a semiconductor element includes a step of designing the function and performance of the device, a step of manufacturing a wafer from a silicon material, an actual circuit on the wafer by lithography technology, etc. The wafer is manufactured through a wafer processing step, a device assembly step (including a dicing process, a bonding process, and a packaging process), an inspection step, and the like. The wafer processing step includes a lithography step (a step of applying a resist (sensitive material) on the wafer, exposure to the wafer by the electron beam exposure apparatus and the exposure method thereof according to the above-described embodiment) A step of performing (drawing), a step of developing the exposed wafer), an etching step for removing the exposed member other than the portion where the resist remains by etching, and a resist for removing the unnecessary resist after the etching. Including a removal step. The wafer processing step may further include a pre-process (an oxidation step, a CVD step, an electrode formation step, an ion implantation step, etc.) prior to the lithography step. By executing the above-described exposure method using the beam exposure apparatus 100, a device pattern is formed on the wafer, so that highly integrated microdevices can be manufactured with high productivity (yield). In the lithography step (exposure process), the above-described complementary lithography is performed, and at that time, the above-described exposure method is executed using the electron beam exposure apparatus 100 of the above-described embodiment. The device can be manufactured.

It should be noted that the disclosure of the international publication relating to the exposure apparatus and the like cited in the above embodiment and the disclosure of the US patent specification are incorporated herein by reference.

As described above, the exposure apparatus, the exposure method, the lithography method, and the device manufacturing method according to the present invention are suitable for manufacturing a micro device.

DESCRIPTION OF SYMBOLS 10 ... Shuttle, 20 ... Multi-beam optical system, 23 ... Optical system, 28 ... Beam shaping aperture plate, 28a ... Aperture, 29 ... Blanking aperture array, 38A, 38B, 38C, 38D ... Electromagnetic lens, 50 ... Main controller 85 ... Coarse / fine motion stage 86: Coarse motion stage drive system 90 ... Fine motion stage drive system 92 ... Electron beam irradiation device 100 ... Electron beam exposure device W ... Wafer

Claims (9)

1. An exposure apparatus that exposes a target by irradiating a charged particle beam,
   A beam shaping member having a plurality of openings arranged along a first direction in a predetermined plane parallel to the surface of the target and a second direction intersecting the first direction in the predetermined plane; and the plurality of openings And an optical system that irradiates the target with the charged particle beam that has passed through each of the plurality of apertures, and the plurality of apertures are configured such that positional deviations of the plurality of charged particle beams that irradiate the target are less than an allowable value. An irradiation device arranged,
   The arrangement of the plurality of openings is determined in consideration of positional information of the charged particle beam caused by Coulomb force acting between the charged particle beams obtained by changing a distance between the charged particle beams. apparatus.
2. The distance between the adjacent openings is determined to be a distance corresponding to a distance of 2 pitches or more of the line portion of the line and space pattern formed on the target,
   The exposure apparatus according to claim 1, wherein the charged particle beam that has passed through each of the plurality of openings cuts a line portion of the line-and-space pattern.
3. A stage holding and moving the target;
   A control device that controls the relative movement between the stage and the optical system, and adjusts the position of the charged particle beam applied to the target;
   The arrangement of the plurality of openings is determined in consideration of an adjustment capability of the control device that adjusts a position of the charged particle beam irradiated to the target for cutting the line portion. Exposure equipment.
4. The optical system individually sets an ON state in which the charged particle beam is irradiated on the target and an OFF state in which the charged particle beam is not irradiated on the target for each of the charged particle beams that have passed through the plurality of openings. Is possible,
   The beam shaping member is disposed in proximity to each of the plurality of openings through which the charged particle beam used for cutting the line portion passes, and the charged particle beam not used for cutting the line portion includes A plurality of auxiliary openings each passing therethrough,
   The control device controls the ON state and the OFF state of the charged particle beam that passes through the auxiliary opening, thereby irradiating the charged particle beam in the ON state used for cutting the line portion. The exposure apparatus according to claim 3, wherein the exposure is adjusted.
5. The first direction is a periodic direction of the line and space pattern,
   In the beam shaping member, auxiliary openings are disposed on one side and the other side of the first direction with respect to each of the plurality of openings.
   The control device selectively cuts the line portion by turning on a pair of the charged particle beams that pass through auxiliary openings located on one side and the other side of the opening in the first direction. The exposure apparatus according to claim 4, which adjusts an irradiation position of the charged particle beam that is in the on state and is used in an exposure.
6. The control device controls the charged particle beam irradiation timing while driving the stage in a direction intersecting the first direction within the predetermined plane, whereby the charged particles used for cutting the line portion The exposure apparatus according to any one of claims 1 to 5, wherein an irradiation position of the beam on the line portion is adjusted.
7. Exposing a target with an exposure apparatus to form a line and space pattern on the target;
   7. A lithography method comprising: using the exposure apparatus according to claim 1 to cut a line pattern constituting the line and space pattern.
8. By cutting the line pattern,
   A dummy that passes through an opening provided in the beam shaping member close to an opening through which the predetermined number of charged particle beams pass, together with a predetermined number of the charged particle beams for cutting the line pattern to be cut. The lithography method according to claim 7, wherein the charged particle beam is turned on to adjust an irradiation position on at least a part of the predetermined number of the charged particle beams on the target.
9. A device manufacturing method including a lithography process,
   9. A device manufacturing method in which exposure of a target is performed by the lithography method according to claim 7 or 8 in the lithography process.

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