TW201631406A - Measurement device and measurement method, exposure apparatus and exposure method, and device manufacturing method - Google Patents

Abstract

This measurement device measures the positions of a first grid mark (GMa) and a second grid mark (GMb) which have periodic directions different from each other, and are provided on a wafer (W). The measurement device is provided with: a mark detection system (50) that includes an irradiation system (70) which, when the wafer (W) is moved in a scanning direction (Y-axis direction) different from the periodic directions of the first and second grid marks, irradiates the first and second grid marks (GMa, GMb) with measurement lights (L1, L2) via an objective lens (62) while performing scanning in the scanning direction, and includes a light reception system (80) which receives diffracted light of the measurement lights from the first and second grid marks, respectively; and an arithmetic processing system which calculates positional information of the first and second grid marks (GMa, GMb) on the basis of the light receiving result of the diffracted light by the light reception system.

Description

Measuring device and measuring method, exposure device and exposure method, and component manufacturing method

The present invention relates to a measuring device and a measuring method, an exposure device and an exposure method, and a component manufacturing method, and more particularly to a measuring device and a measuring method for measuring position information of a lattice mark provided on an object, and a measuring device An exposure apparatus, an exposure method using the measurement method, and a component manufacturing method using an exposure apparatus or an exposure method.

Conventionally, in the lithography step of manufacturing a semiconductor element (integrated circuit or the like) or an electronic component (microdevice) such as a liquid crystal display element, a step-and-scan type projection exposure apparatus (so-called scanning stepper (also referred to as a scanner) is used. )Wait.

In such an exposure apparatus, since a plurality of layers are formed by overlapping, for example, on a wafer or a glass plate (hereinafter, collectively referred to as "wafer"), a pattern for forming a wafer, a mask, or a mark is performed. A line (hereinafter, collectively referred to as "reticle") has an operation in which the pattern is in an optimum relative positional relationship (so-called alignment). Further, as an alignment system (sensor) used for such alignment, a detector that scans the measurement light by scanning the measurement light on the wafer is known (for example, Patent Document 1) .

Here, in order to improve the alignment accuracy of the reticle and the wafer, it is preferable to align When more grid marks are detected (position measurement), the more the number of detection objects with grid marks, the lower the yield.

Patent Document 1: US Patent No. 8593646

The measurement device according to the first aspect is configured to measure positional information of the first lattice mark and the second lattice mark which are different in the periodic direction of the object, and is characterized in that: the mark detection system includes the mark detection system When the lattice mark and the second lattice mark move in a predetermined scanning direction in which the periodic directions are different, the measurement light is transmitted through the objective lens while the measurement light is scanned in the scanning direction with respect to the first lattice mark and the second lattice mark. a light irradiation system, and a light receiving system that receives the diffracted light of the measurement light from the first lattice mark and the second lattice mark through the objective lens; and an arithmetic processing system, the light receiving result of the diffraction light according to the light receiving system The position information of the first lattice mark and the second lattice mark is obtained.

The measurement device according to the second aspect includes a mark detection system that has an illumination system that emits the measurement light while scanning the measurement light with respect to the lattice mark of the object moving in the first direction in the first direction. a pair of objective optical systems that oppose the object optics in the first direction, and a light receiving system that receives the diffracted light from the grid mark through the pair of object optics; and an arithmetic system The detection result of the mark detection system is obtained, and the position information of the check mark is obtained.

An exposure apparatus according to a third aspect includes: a first or second aspect measuring device; a position control device that controls a position of the object based on an output of the measuring device; and a pattern forming device that irradiates the object with an energy beam to form a predetermined pattern .

The exposure apparatus of the fourth aspect includes the measuring device of the first or second aspect; The object is irradiated with an energy beam while the position of the object is controlled according to the output of the measuring device to form a predetermined pattern on the object.

The exposure apparatus according to the fifth aspect is characterized in that the object is irradiated with an energy beam to form a predetermined pattern on the object, and the mark detection system includes the measurement light that is moved in the first direction with respect to the measurement light. And the first lattice mark and the second lattice mark which are different from the first direction and different from each other in the first direction, and the second lattice mark is irradiated to the first direction, and the illumination system is irradiated with the measurement light through the objective lens, and is received by the objective lens. The light receiving system of the diffracted light of the measurement light of the first lattice mark and the second lattice mark; and the position of the object is controlled based on the detection result of the mark detection system.

The device manufacturing method according to the sixth aspect includes the operation of exposing the substrate using the exposure apparatus according to any one of the third to fifth aspects, and the operation of developing the exposed substrate.

The measurement method according to the seventh aspect is characterized by measuring position information of the first lattice mark and the second lattice mark which are different in the periodic direction of the object, and includes: causing the object to mark the first lattice and the The second lattice mark moves in a predetermined scanning direction in which the periodic direction is different; and when the object moves in the scanning direction, the measurement light is scanned in the scanning direction with respect to the first lattice mark and the second lattice mark. The operation of irradiating the measurement light through the objective lens; receiving, by the objective lens, the operation of the diffracted light from the measurement light of the first lattice mark and the second lattice mark; and obtaining the first light based on the light receiving result of the diffracted light The action of the 1 grid mark and the position information of the 2nd grid mark.

The measurement method according to the eighth aspect is characterized in that the position information of the lattice mark provided on the object is measured, and includes: an operation of moving the object in the first direction; and when the object moves in the first direction, Measuring light is scanned in the first direction with respect to the lattice mark The operation of illuminating the measuring light through the objective optical system; the operation of receiving the diffracted light from the grating mark by the light receiving system through the objective optical system; and obtaining the grating based on the light receiving result of the light receiving system The action of marking the location information.

The exposure method according to the ninth aspect includes: measuring the position information of the grid mark provided on the object using the measurement method of the seventh or eighth aspect; and controlling the position of the object based on the position information of the grid mark measured The action of exposing the object with an energy beam.

The device manufacturing method according to the tenth aspect includes the operation of exposing the substrate by the exposure method of the ninth aspect, and the operation of developing the exposed substrate.

10‧‧‧Exposure device

14‧‧‧Marking line stage

20‧‧‧ wafer stage device

30‧‧‧Main control unit

50‧‧‧Alignment

GM‧‧‧ lattice mark

W‧‧‧ wafer

Fig. 1 is a view schematically showing the configuration of an exposure apparatus of an embodiment.

2(a) to 2(c) are views showing an example (1 to 3) of the lattice marks formed on the wafer.

Fig. 3 is a view showing the configuration of an alignment system of the exposure apparatus of Fig. 1.

Fig. 4 is a plan view showing the grid for detection of the alignment system of Fig. 3.

Fig. 5 is a view showing an example of a signal obtained from the light receiving system of the alignment system of Fig. 3.

Figure 6 is a block diagram showing the control system of the exposure apparatus.

Fig. 7(a) shows a lattice mark of a modification, and Fig. 7(b) shows a view of an operation when measuring the position of the lattice mark of Fig. 7(a).

Fig. 8(a) is a view showing the measurement light and the diffracted light which are incident on the lattice mark from the alignment system of the modification, and Figs. 8(b) and 8(c) show the measurement light and the diffraction light at the objective lens. A map of the position on the face (1 and 2).

Fig. 9 is a view showing a modification of the light receiving system of the alignment system.

(embodiment)

Hereinafter, an embodiment will be described with reference to Figs. 1 to 6 .

Fig. 1 is a view schematically showing the configuration of an exposure apparatus 10 of the embodiment. The exposure device 10 is a step-and-scan type projection exposure device, a so-called scanner. As will be described later, in the present embodiment, the projection optical system 16b is provided. Hereinafter, the direction parallel to the optical axis AX of the projection optical system 16b is the Z-axis direction, and the reticle R and the crystal are in the plane orthogonal thereto. The direction of the circle W relative to the scanning is the Y-axis direction, the direction orthogonal to the Z-axis and the Y-axis is the X-axis direction, and the directions of rotation (tilting) around the X-axis, the Y-axis, and the Z-axis are θ x and θ, respectively. The y and θ z directions will be described.

The exposure apparatus 10 includes an illumination system 12, a reticle stage 14, a projection unit 16, a wafer stage apparatus 20 including a wafer stage 22, a multi-point focus position detection system 40, an alignment system 50, and the like. . In FIG. 1, the wafer W is placed on the wafer stage 22.

The illumination system 12 includes, for example, a light source and an illumination optical system having an illuminance uniformization optical system including an optical integrator and a reticle shield (none of which is shown), as disclosed in the specification of the U.S. Patent Application Publication No. 2003/0025890. The illumination system 12 illuminates the slit-like illumination area IAR on the reticle R of the reticle R set (restricted) by the illumination light (exposure light) IL with a substantially uniform illumination illumination reticle shutter (mask system) . As the illumination light IL, for example, ArF excimer laser light (wavelength: 193 nm) is used.

A reticle R on which a circuit pattern is formed on a pattern surface (lower side in FIG. 1) is fixed to the reticle stage 14 by, for example, vacuum suction. The reticle stage 14 can be micro-driven in the XY plane by a reticle stage drive system 32 (not shown in FIG. 1, not shown in FIG. 1) including, for example, a linear motor or the like. It is movable and can be driven in the scanning direction at a predetermined scanning speed (the Y-axis direction in the left and right directions in the paper surface in Fig. 1). The position information (including the amount of rotation information in the θ z direction) of the reticle stage 14 in the XY plane is, for example, by a reticle-mounted stage measurement system 34 including, for example, an interferometer system (or an encoder system). The analytical ability of 0.5~1nm is measured at any time. The measured value of the reticle load stage measurement system 34 is transmitted to the main control unit 30 (not shown in Fig. 1, see Fig. 6). The main control device 30 calculates the position of the reticle stage 14 in the X-axis direction, the Y-axis direction, and the θ z direction based on the measured value of the reticle stage measurement system 34, and controls the reticle stage based on the calculation result. The drive train 32 controls the position (and speed) of the reticle stage 14 thereby. Further, although not shown in Fig. 1, the exposure apparatus 10 is provided with a reticle alignment system 18 for detecting the position of the reticle alignment mark formed on the reticle R (see Fig. 6). As the reticle alignment system 18, an alignment system constructed as disclosed in, for example, the specification of U.S. Patent No. 5,464,413, the specification of U.S. Patent Application Publication No. 2002/0041377, and the like can be used.

The projection unit 16 is disposed below the reticle stage 14 in FIG. The projection unit 16 includes a lens barrel 16a and a projection optical system 16b housed in the lens barrel 16a. As the projection optical system 16b, for example, a refractive optical system composed of a plurality of optical elements (lens elements) arranged along an optical axis AX parallel to the Z-axis direction is used. The projection optical system 16b is, for example, telecentric on both sides and has a predetermined projection magnification (for example, 1/4, 1/5, 1/8, etc.). Therefore, when the illumination region 12 illuminates the illumination region IAR on the reticle R, the illumination light IL of the reticle surface R disposed substantially in line with the first surface (object surface) of the projection optical system 16b by the pattern surface is used. The reduced image of the circuit pattern of the reticle R in the illumination area IAR (the portion of the circuit pattern is reduced) is formed by the projection optical system 16b (projection unit 16) on the second surface (image surface) of the projection optical system 16b. The side is a region (hereinafter referred to as an exposure region) IA on the wafer W to which the photoresist (sensing agent) is coated, which is conjugate with the illumination region IAR. Then, by The reticle stage 14 moves in synchronization with the wafer stage 22 to move the reticle R relative to the illumination area IAR (illumination light IL) in the scanning direction (Y-axis direction), and the wafer W is opposed to the exposure area IA. (The illumination light IL) moves in the scanning direction (Y-axis direction), thereby performing scanning exposure of one irradiation region (regional region) on the wafer W, and transferring the pattern of the reticle R in the irradiation region. That is, in the present embodiment, a pattern is formed on the wafer W by the illumination system 12, the reticle R, and the projection optical system 16b, and the sensing layer (photoresist layer) on the wafer W is performed by the illumination light IL. The exposure forms the pattern on the wafer W.

The wafer stage device 20 includes a wafer stage 22 disposed above the susceptor 28. The wafer stage 22 includes a stage body 24 and a wafer stage 26 mounted on the stage body 24. The stage main body 24 is supported by the susceptor 28 through a gap of about several μm by a non-contact bearing (not shown) fixed to the bottom surface thereof, for example, an air bearing. The stage body 24 can be driven in a horizontal plane of 3 degrees of freedom with respect to the base 28 by a wafer stage drive system 36 (not shown in FIG. 1, not shown in FIG. 6) including, for example, a linear motor (or a planar motor) (X , Y, θ z). The wafer stage drive system 36 includes a micro drive system that drives the wafer stage 26 to the stage body 24 in a six-degree-of-freedom direction (X, Y, Z, θ x, θ y, θ z). The positional information of the 6-degree-of-freedom direction of the wafer table 26 is measured at any time by, for example, a wafer-mounted stage measurement system 38 including an interferometer system (or an encoder system) with an analytical capability of, for example, about 0.5 to 1 nm. The measured values of the wafer stage measurement system 38 are transmitted to the main control unit 30 (not shown in FIG. 1, see FIG. 6). The main control unit 30 calculates the position of the wafer stage 26 in the six-degree-of-freedom direction based on the measured value of the wafer-mounted stage measurement system 38, and controls the wafer stage drive system 36 based on the calculation result, thereby controlling the position of the wafer stage 26. (and speed). Main control device 30 also controls the position of stage 24 in the XY plane based on the measured values of wafer stage measurement system 38.

The multi-point focus position detection system 40 is described, for example, in U.S. Patent No. 5,448,332. A position measuring device for obliquely incident mode of measuring the position information of the wafer W in the Z-axis direction, which is the same as that disclosed in the above. As shown in FIG. 1, the multi-point focus position detecting system 40 is disposed on the more-Y side of the alignment system 50 disposed on the -Y side of the projection unit 16. Since the output of the multi-point focus position detecting system 40 is used for an autofocus device to be described later, the multi-point focus position detecting system 40 will hereinafter be referred to as an AF system 40.

The AF system 40 includes an illumination system that irradiates a plurality of detection beams onto the surface of the wafer W, and a light receiving system that receives reflected light from the plurality of detection beams on the surface of the wafer W (all not shown). Although a plurality of detection points (irradiation points of the detection beam) of the AF 40 are not shown, they are arranged on the detection surface at predetermined intervals along the X-axis direction. In the present embodiment, for example, a matrix of one row of M rows (M is the total number of detection points) or two rows of N rows (N is 1/2 of the total number of detection points) is arranged. The output of the light receiving system is supplied to the main control unit 30 (refer to Fig. 6). The main controller 30 obtains position information (surface position information) of the surface of the wafer W in the Z-axis direction of the plurality of detection points based on the output of the light receiving system. In the present embodiment, the detection area (the arrangement area of the plurality of detection points) on which the surface position information of the AF system 40 is formed is set to a strip shape extending in the X-axis direction.

The main control device 30 moves the wafer W to the Y-axis and/or the X-axis direction with respect to the detection region of the AF system 40 before the exposure operation, and obtains the surface of the wafer W based on the output of the AF system 40 at this time. Location information. The main control unit 30 acquires the above-described surface position information for all the irradiation areas set on the wafer W, and correlates the result with the position information of the wafer stage 26, and stores it as focus mapping information.

Next, the alignment mark formed on the wafer W and the off-axis alignment system 50 used for the detection of the alignment mark will be described.

Each of the irradiation regions on the wafer W is used as a detection target of the alignment system 50. There is at least one lattice mark GM shown in Fig. 2(a). Further, the lattice mark GM is actually formed in the scribe line of each of the irradiation regions.

The lattice mark GM includes a first lattice mark GMa and a second lattice mark GMb. The first lattice mark GMa is composed of a reflection type diffraction grating which extends in a direction of an angle of 45° with respect to the X axis in the XY plane (hereinafter, conveniently referred to as an α direction). The lattice line is formed in a direction perpendicular to the α direction (hereinafter, referred to as a β direction in the XY plane) at a predetermined interval (for example, a pitch P1 (P1 is an arbitrary value)), and a reflection type diffraction in a β direction is a periodic direction. Grating. The second lattice mark GMb is a reflection type diffraction grating in which the lattice line extending in the β direction is formed at a predetermined interval (for example, the pitch P2 (P2 is an arbitrary value)) in the α direction, and the α direction is the periodic direction. The first lattice mark GMa and the second lattice mark GMb are arranged continuously (adjacent) in the X-axis direction so that the positions in the Y-axis direction are the same. In addition, in FIG. 2(a), for convenience of illustration, the lattice pitch is shown to be much larger than the actual distance. The diffraction gratings in the other figures are also the same. In addition, the pitch P1 and the pitch P2 may be the same value or different values. Further, in Fig. 2(a), although the first lattice mark GMa and the second lattice mark GMb are in contact with each other, they may not be in contact with each other.

As shown in FIG. 3, the alignment system 50 includes an objective optical system 60 including an objective lens 62, an illumination system 70, and a light receiving system 80.

The irradiation system 70 includes a light source 72 that emits the measurement light L1, L2, a movable mirror 74 disposed on the optical path of the measurement light L1, L2, and a portion of the measurement light L1, L2 that reflects the movable mirror 74 is reflected toward the wafer W, so that the rest A partially penetrating half mirror (beam splitter) 76, a beam position detecting sensor 78 disposed on the optical path of the measuring light L1, L2 penetrating (passing) the half mirror 76, and the like.

The light source 72 does not emit the two measurement lights L1, L2 of the wavelength of the broadband which is applied to the photoresist of the wafer W (see FIG. 1) in the -Z direction. In addition, in Fig. 3, the light of the measuring light L2 is measured. The light path of the road and the measuring light L1 overlaps on the inner side of the paper. In the present embodiment, for example, white light is used as the measurement light L1 and L2.

As the movable mirror 74, in the present embodiment, for example, a known current mirror is used. In the movable mirror 74, the reflecting surface for reflecting the measuring light L1, L2 is rotatable (rotated) about an axis parallel to the X-axis. The rotation angle of the movable mirror 74 is controlled by the main control unit 30 (not shown in Fig. 3, see Fig. 6). The angle control of the movable mirror 74 will be described later. Further, as long as the reflection angle of the measurement light L1, L2 can be controlled, an optical member other than the current mirror (for example, helium or the like) can be used. Further, the measurement light L1, L2 may be reflected by a single current mirror, and two current mirrors may be provided corresponding to the measurement light L1, L2.

The half mirror 76 is different from the movable mirror 74 in that the position (angle of the reflecting surface) is fixed. A portion of the measurement light L1, L2 reflected by the reflecting surface of the movable mirror 74 is bent in the -Z direction by the half mirror 76, and then transmitted through the objective lens 62 substantially perpendicularly into the lattice mark GM formed on the wafer W ( GMa, GMb). Further, in Fig. 3, the movable mirror 74 is inclined at an angle of 45 with respect to the Z axis, and one of the measurement lights L1, L2 from the movable mirror 74 is reflected by the half mirror 76 in a direction parallel to the Z axis. Further, in Fig. 3, only the movable mirror 74 and the half mirror 76 are disposed on the optical path of the measuring light L1, L2 between the light source 72 and the objective lens 62, but the movable mirror 74 is inclined at an angle other than 45 with respect to the Z axis. In other cases, the irradiation system 70 is configured such that the measurement light L1, L2 emitted from the objective lens 62 is incident substantially perpendicularly on the lattice mark GM formed on the wafer W. In this case, at least another optical member different from the movable mirror 74 and the half mirror 76 may be disposed on the optical path of the measuring light L1, L2 between the light source 72 and the objective lens 62. The measurement light L1, L2 passing through (penetrating) the half mirror 76 is incident on the beam position detecting sensor 78 through the lens 77. The beam position detecting sensor 78 has a photoelectric conversion element such as a PD (Photo Detector) array or a CCD (Charge Coupled Device) whose imaging surface is disposed on a surface conjugate with the surface of the wafer W.

Here, the interval between the measurement lights L1 and L2 is set such that the measurement light L1 is irradiated onto the first lattice mark GMa and the measurement light L2 is irradiated onto the second lattice mark GMb among the measurement lights L1 and L2 emitted from the light source 72 ( Refer to Figure 2(a)). Further, in the alignment system 50, when the angle of the reflection surface of the movable mirror 74 is changed, the incident (irradiation) position of the measurement light L1, L2 on the lattice marks GMa, GMb (wafer W) and the movable mirror 74 are respectively The angle of the reflecting surface changes correspondingly in the scanning direction (Y-axis direction) (refer to the white arrow in Fig. 2(a)). Further, in conjunction with the change in position of the measurement lights L1, L2 on the lattice mark GM, the incident positions of the measurement lights L1, L2 on the beam position detecting sensor 78 also change. The output of the beam position detecting sensor 78 is supplied to the main control unit 30 (not shown in Fig. 3, see Fig. 6). The main control device 30 can obtain the irradiation position information of the measurement lights L1, L2 on the wafer W based on the output of the beam position detecting sensor 78.

The objective optical system 60 includes an objective lens 62, a detector side lens 64, and a grating plate 66. In the alignment system 50, when the measurement mark L1 is irradiated to the first lattice mark GMa in a state where the lattice mark GM is located directly below the objective optical system 60, the measurement light L1 generated from the first lattice mark GMa is used as the basis. A plurality of (a plurality of light corresponding to the plurality of wavelengths of light contained in the white light) ±1 times of the diffracted light ±L3 is incident on the objective lens 62. Similarly, when the measurement light L2 is irradiated to the second lattice mark GMb, the objective lens 62 is incident on the plurality of ±1 times of the diffracted light ±L4 based on the measurement light L2 generated from the second lattice mark GMb. The ±1st diffracted light ±L3, ±L4 is incident on the detector side lens 64 disposed above the objective lens 62 through the objective lens 62, respectively. The detector side lens 64 converges ±1 times of the diffracted light ±L3 and ±L4 on the grid plate 66 disposed above the detector side lens 64, respectively.

As shown in FIG. 4, the grating plate 66 is formed with readout diffraction gratings Ga and Gb extending in the Y-axis direction. The diffraction grating Ga for reading is a transmissive diffraction grating having a periodic direction in the β direction corresponding to the lattice mark GMa (see FIG. 2(a)). Reading diffraction grating Gb system and lattice The mark GMb (refer to FIG. 2(a)) corresponds to a penetrating diffraction grating having a periodic direction in the α direction. Further, in the present embodiment, the distance between the diffraction gratings Ga for reading is set to be substantially the same as the distance between the grating marks GMa, and the distance between the diffraction gratings Gb for reading is set to be substantially the distance from the lattice mark GMb. Same on the same.

Referring back to Fig. 3, the light receiving system 80 includes a detector 84 and an optical system 86 for guiding the light to the detector 84 corresponding to the image (interference fringe) based on the diffraction light ±L3 and ±L4 formed on the grating plate 66. .

The light corresponding to the image (interference fringes) formed on the diffraction gratings Ga, Gb (see FIG. 4) for reading is guided to the detector 84 through the mirror 86a of the optical system 86. As described above, in the alignment system 50 of the present embodiment, the optical system 86 has the spectroscopic grating 86b corresponding to the white light as the measurement lights L1 and L2. Light from the grid plate 66 is split by the beam splitter 86 into light, for example, blue, green, and red. The detector 84 has photodetectors PD1 to PD3 which are independently provided corresponding to the respective colors described above. The output of each of the photodetectors PD1 to PD3 of the detector 84 is supplied to the main control unit 30 (not shown in Fig. 3, see Fig. 6).

As an example, the waveform signals (interference signals) shown in FIG. 5 can be obtained from the outputs of the photodetectors PD1 to PD3, respectively. The main control device 30 (see Fig. 6) calculates the positions of the lattice marks GMa and GMb from the phase of the signal by calculation. That is, the exposure apparatus 10 (see FIG. 1) of the present embodiment is configured by the alignment system 50 and the main control unit 30 (see FIG. 6 respectively) for determining the position information of the grid mark GM formed on the wafer W. Alignment device.

Referring back to FIG. 3, the main control unit 30 (see FIG. 6) performs the position measurement of the grid mark GM using the alignment system 50, while making the grid mark GM (ie, the wafer W) to the Y axis with respect to the alignment system 50. The direction driving controls the movable mirror 74, thereby causing the measuring light L1, L2 to follow the grid mark The GM is scanned in the Y-axis direction (see Fig. 2(a)). Thereby, since the lattice mark GM and the grid plate 66 relatively move in the Y-axis direction, the interference fringes are respectively interfered by the interference of the diffracted lights based on the measurement light L1 and the diffracted lights based on the measurement light L2, respectively. The image is formed on the readout diffraction gratings Ga, Gb on the grid plate 66. The interference fringes imaged on the grid plate 66 are detected by the detector 84. The output of the detector 84 is supplied to the main control unit 30. Further, the waveform shown in Fig. 5 is generated based on the relative movement of the lattice marks GMa, GMb and the read diffraction gratings Ga, Gb (see Fig. 4), and the measurement light L1 irradiated onto the lattice marks GMa, GMb. The position of L2 is generated independently. Therefore, the scanning of the grid marks GMa, GMb (that is, the wafer stage 22) in the Y-axis direction and the measurement of the light L1, L2 in the Y-axis direction may not be completely synchronized (the speed is strictly consistent).

Fig. 6 is a block diagram showing the main configuration of the control system of the exposure apparatus 10. The control of FIG. 6 includes a so-called microcomputer (or workstation) composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., to coordinate the overall control of the entire control device. The device 30 is constructed in a center.

In the exposure apparatus 10 (see FIG. 1) configured as described above, first, the reticle R and the wafer W are loaded onto the reticle stage 14 and the wafer stage 22, respectively, and the reticle alignment system 18 is used ( Refer to FIG. 6) for alignment of the reticle and alignment of the wafer using the alignment system 50 (for example, EGA (Enhanced Overall Alignment), etc.). In addition, preparations for the above-described reticle alignment, baseline measurement, and the like are disclosed in, for example, the specification of U.S. Patent No. 5,464,413, the specification of U.S. Patent Application Publication No. 2002/0041377, and the like. Further, the EGA connected hereto is disclosed in detail, for example, in the specification of U.S. Patent No. 4,780,617.

Here, in the present embodiment, the main controller 30 obtains the wafer surface position information using the AF system 40 before the position measurement operation using the grid mark GM of the alignment system 50. Next, the main controller 30 controls the position and posture (the inclination of the θ x direction and the θ y direction) of the wafer table 26 in the Z-axis direction based on the surface position information and the offset value obtained in advance for each layer, thereby The optics optical system 60 of alignment system 50 is focused on the grid mark GM. Further, in the present embodiment, the offset value means the measured value of the AF system 40 obtained when the position and posture of the wafer table 26 are adjusted such that the signal intensity of the alignment system 50 (the contrast of the interference fringes) is maximized. As described above, in the present embodiment, the position and posture of the wafer table 26 are controlled substantially instantaneously using the surface position information of the wafer W obtained immediately before the detection of the lattice mark GM by the alignment system 50 (automatic focus control) ). Further, in parallel with the position measurement of the lattice mark GM, the light from the mark mark GM of the position measurement target may be received to detect the surface position of the wafer W.

Thereafter, under the management of the main control device 30, the wafer stage 22 is driven to the acceleration start position for exposing the first irradiation region of the wafer W, and the position of the reticle R is the acceleration start position. The reticle stage 14 is driven. Next, the reticle stage 14 and the wafer stage 22 are synchronously driven in the Y-axis direction to expose the first irradiation region on the wafer W. Thereafter, exposure of the wafer W is completed by performing exposure to all of the irradiated regions on the wafer W.

According to the alignment system 50 of the exposure apparatus 10 of the present embodiment described above, the wafer W (wafer stage 22) is moved in the Y-axis direction, and the measurement light L1, L2 is simultaneously marked with the grid mark GM (refer to each 3) scanning in the Y-axis direction, the position measurement operation of the lattice mark GM can be performed in parallel with the movement operation of the wafer stage 22 to the exposure start position, and the movement operation of the wafer stage 22 to the exposure start position is, for example, The wafer W is loaded on the wafer stage 22 and then performed. In this case, the alignment system 50 may be disposed in advance on the moving path of the wafer stage 22. Thereby, the alignment measurement time can be shortened, and the overall yield can be improved.

Further, at the position measurement of the lattice mark GM, the alignment system 50 irradiates the measurement light L1 to the first lattice mark GMa of the lattice mark GM, and irradiates the measurement mark L2 different from the measurement light L1 to the lattice mark GMb. That is, in the present embodiment, the alignment system 50 independently illuminates the pair of measurement lights L1, L2 with respect to the lattice marks GMa, GMb, which are different from each other in the periodic direction. Thereby, since the positional information of each of the lattice marks GMa and GMb is obtained in parallel, the position measurement time of the lattice marks GMa and GMb can be shortened. Therefore, the yield reduction can be suppressed by comparing the position information of the grid marks GMa and GMb in comparison with the assumption.

Further, in the present embodiment, the pair of lattice marks GMa and GMb are arranged in the direction orthogonal to the scanning direction (Y-axis direction) of the measurement lights L1 and L2 (X-axis direction), respectively. In the case where the lattice marks GMa and GMb are arranged along the scanning direction, the stroke of the measuring light L1, L2 can be shortened. Therefore, the measurement time can be shortened and the yield can be improved. Further, since the measurement light L1 and L2 have a short stroke, the size of the objective optical system 60 of the alignment system 50 can be reduced.

Further, since the alignment system 50 of the present embodiment scans the measurement light so as to follow the wafer W (lattice mark GM) moving in the scanning direction, it can be measured for a long time. Therefore, since the moving average of the so-called output can be obtained, the influence of the vibration of the device can be reduced. Further, when a line sensor and a spatial mark are detected by an image sensor (for example, a CCD or the like) as the light receiving system of the alignment system, when the measurement light is scanned following the wafer W moving in the scanning direction, the scanning direction cannot be detected. An image that is completely parallel to the line (like deformation). On the other hand, in the present embodiment, since the positional measurement of the lattice mark GM is performed by interfering with the diffracted light from the lattice mark GM, the mark detection can be surely performed.

Moreover, the alignment system 50 of the present embodiment functions as a detector 84 corresponding to white light. That is, the measurement light L1, L2 has, for example, three photodetectors PD1 to PD3 (for blue light, green light, and red light, respectively). Therefore, for example, the white mark is used to detect the overlap mark (not shown) formed on the wafer W before the wafer alignment, and the color of the highest interference light is determined in advance, thereby determining the above-mentioned three, for example, three. Which of the photodetectors PD1~PD3 is best suited for wafer alignment.

Further, the alignment system of the above embodiment and the detection system and method including the lattice marks of the alignment system can be appropriately changed. For example, in the above-described embodiment, as shown in FIG. 2(a), the pair of lattice marks GMa and GMb respectively correspond to the pair of measurement lights L1 and L2, but the present invention is not limited thereto, for example, FIG. 2(b) It is also possible to illuminate a (widely) single measurement light L1 extending in the X-axis direction to a pair of lattice marks GMa, GMb. In this case, the single measurement light L1 has an illumination region in the X-axis direction that can illuminate a region including at least a part of the lattice mark GMa and at least a part of the lattice mark GMb. Further, in the X-axis direction, the single measurement light L1 may illuminate all of the regions including the lattice mark GMa and the lattice mark GMb.

Further, in the above-described embodiment, as shown in Fig. 2(a), the pair of lattice marks GMa and GMb are arranged along the X-axis direction, but the present invention is not limited thereto. For example, as shown in Fig. 2(c), a pair of lattice marks are shown. GMa, GMb can also be arranged along the Y-axis direction. In this case, the alignment measurement is performed by moving the wafer W (lattice mark GM) in the X-axis direction (see the black arrow in FIG. 2(c)) and scanning the measurement lights L1 and L2 in the X-axis direction. Just align the system.

Further, the lattice marks GMa and GMb in the above-described embodiment have an angle of, for example, 45° with respect to the X-axis and the Y-axis, but are not limited thereto. For example, as shown in FIG. 7(a), the wafer W is formed. There is a lattice mark GM including a lattice mark GMy whose cycle direction is the Y-axis direction and a lattice mark GMx whose cycle direction is the X-axis direction.

In this case, as shown in FIG. 7(b), as long as the wafer W (lattice mark GM) is wound The Z-axis is rotated by a predetermined angle θ (the angle θ is not particularly limited. However, in the state of 0° < θ < 90°), the wafer W may be moved in the Y-axis direction. The alignment system 50 (not shown in FIG. 7(b). Referring to FIG. 3), the measurement light L1 is irradiated to the lattice mark GMx, and the measurement light L2 is irradiated to the lattice mark GMy, and the measurement light L1, L2 is made to Y. Axis direction scanning. Thereby, as in the above embodiment, the positional information of the lattice mark GM in the XY plane can be obtained.

Further, in the above-described embodiment, the measurement light L1, L2 emitted from the alignment system 50 is perpendicularly incident on the lattice mark GM, but the present invention is not limited thereto, and the lattice mark GM may be incident at a predetermined angle (that is, the inclination). For example in FIG. 8 (a), the angle of incidence θ ₁ of the measuring wavelength λ of light incident on the grating pitch L p is a lattice of GM mark, diffracted angle [theta] of the diffracted light L ₂ from the lattice mark GM '. Here, since λ/p=sin(θ ₁ )+sin(θ ₂ ) holds, even in the oblique incidence mode shown in FIG. 8( a ), even an optical system having the same numerical aperture NA is compared with When the measurement light L is vertically incident on the lattice mark GM, the position measurement of the fine pitch mark GM can be performed.

Here, in the above-described embodiment, since the position of the lattice mark GM is interfered by the interference of one of the lattice marks GM from the diffracted light, the oblique incidence mode shown in Fig. 8(a) is also used. As shown in FIG. 8(b), in order to measure the position of the grid mark GM (see FIG. 8(a)) in the orthogonal two-axis direction, the measurement light L is irradiated to the grid mark GM from the four directions in total. Here, Fig. 8(b) is a view showing an image of the pupil plane of the objective lens 62 (direction of light). As described above, the lattice mark GM (see FIG. 2) of the present embodiment has a periodic direction of α or β in the direction of, for example, 45° with respect to the X-axis and the Y-axis. Therefore, the incident direction of the light L and the diffracted light L' are measured. The direction of emission is also in the α or β direction. Further, the periodic direction of the lattice mark of the measurement object may be a direction parallel to the X-axis and the Y-axis. In this case, as shown in FIG. 8(c), the measurement light L is incident on the X-axis and the Y-axis. direction. In this case, the diffracted light L' is parallel to the X-axis and the Y-axis. Shooting.

Further, although the light receiving system 80 of the alignment system 50 of the above embodiment is split into white light by the splitter 86b, the present invention is not limited thereto, and as in the light receiving system 380 shown in Fig. 9, a plurality of split beams may be used. The filter 386 splits the white light toward the photodetectors PD1 to PD3 arranged in respective colors (for example, blue, green, yellow, red, and infrared light).

Further, in the above-described embodiment, white light is used as the measurement light L1 and L2. However, the present invention is not limited thereto. For example, a plurality of lights having different wavelengths from each other may be used.

Further, in the above embodiment, the alignment system 50 is used to detect a lattice mark for alignment (fine alignment) of the reticle pattern and the wafer, but is not limited thereto, and may be, for example, a wafer W. Immediately after being loaded on the wafer stage 22, it is used to detect a search mark formed on the wafer W (a grid mark having a line width larger than the grid mark GMa, GMb thick and having a relatively large pitch).

Further, the arrangement and number of the alignment systems 50 can be appropriately changed. For example, the plurality of alignment systems 50 may be arranged at predetermined intervals in the X-axis direction. In this case, the lattice marks of the plurality of irradiation regions having different positions in the X-axis direction can be simultaneously detected. Further, in this case, a part of the plurality of alignment systems 50 may also move in a slight stroke in the X-axis direction. In this case, a plurality of lattice marks different in position in the X-axis direction formed in one irradiation region can be detected.

Further, the illumination light IL is not limited to ArF excimer laser light (wavelength: 193 nm), and may be ultraviolet light such as KrF excimer laser light (wavelength: 248 nm) or vacuum ultraviolet light such as F ₂ laser light (wavelength: 157 nm). For example, as disclosed in the specification of U.S. Patent No. 70,236,10, as a vacuum ultraviolet light, a single-wavelength laser light from an infrared or visible light region of a DFB semiconductor laser or a fiber laser can be used, for example, doped with germanium (or The optical fiber amplifiers of both of them increase in amplitude, using nonlinear optical crystallographic wavelengths to convert to harmonics of ultraviolet light. Further, the wavelength of the illumination light IL is not limited to light of 100 nm or more, and light of a wavelength of less than 100 nm may be used, for example, EUV exposure of EUV (Extreme Ultraviolet) light using a soft X-ray region (for example, a wavelength range of 5 to 15 nm). The device can also be applied to the above embodiment. Further, an exposure apparatus using a charged particle beam such as an electron beam or an ion beam can also be applied to the above embodiment.

Further, the projection optical system of the exposure apparatus according to the above embodiment may be not only a reduction system but also an equal magnification and amplification system, and the projection optical system PL may be not only a refractive system but also a reflection system and a reflection refraction system. Either of them, the projection image can be either an inverted image or an erect image.

Further, in the above-described embodiment, a light-transmitting type mask (a reticle) in which a predetermined light-shielding pattern (or a phase pattern or a light-reducing pattern) is formed on a light-transmitting substrate is used, but this marking may be replaced. An electronic reticle (also referred to as a variable-shaping reticle, active reticle, or alternatively) that forms a transmissive pattern or a reflective pattern, or an illuminating pattern, using an electronic material according to the pattern to be exposed, as disclosed in US Pat. No. 6,778,257. The image generator includes, for example, a DMD (Digital Micro-mirror Device) such as a non-light-emitting image display element (spatial light modulator).

Further, as an exposure apparatus, for example, a so-called liquid immersion exposure apparatus that performs an exposure operation in a state in which a projection optical system and an exposure target object (for example, a wafer) are filled with a liquid (for example, pure water), as disclosed in the specification of US Pat. No. 8,004,650 It can also be applied to the above embodiment.

Further, for example, an exposure apparatus having two wafer stages disclosed in the specification of the U.S. Patent Application Publication No. 2010/0066992 can be applied to the above embodiment.

Further, for example, as disclosed in International Publication No. 2001/035168, an exposure apparatus (a lithography system) for forming a line and space pattern on a wafer W by forming interference fringes on a wafer W can also be applied to the above embodiment. Further, a reduced projection exposure apparatus in which a stepwise bonding method in which an irradiation area and an irradiation area are combined can be applied to the above embodiment.

Further, for example, as disclosed in the specification of US Pat. No. 6613116, two reticle patterns are synthesized on a wafer through a projection optical system, and an exposure apparatus for substantially simultaneously double-exposure an illumination area on the wafer by one scanning exposure is also used. It can be applied to the above embodiment.

Further, in the above embodiment, the object to be patterned (the object to be exposed by the energy beam irradiation) is not limited to the wafer, and may be another object such as a glass plate, a ceramic substrate, a film member, or a mask substrate.

Further, the use as an exposure apparatus is not limited to an exposure apparatus for semiconductor manufacturing, and can be widely applied, for example, to an exposure apparatus for liquid crystal for transferring a liquid crystal display element pattern to a sheet glass plate, or for manufacturing an organic EL or thin film magnetic head. An exposure device such as a photographic element (CCD or the like), a micromachine, or a DNA wafer. Further, in order to manufacture a microchip such as a semiconductor element, a circuit pattern or a photomask used in a photoexposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, or an electron beam exposure apparatus is used to transfer a circuit pattern to a glass substrate or a crucible. An exposure apparatus such as a wafer can also be applied to the above embodiment.

The electronic component such as a semiconductor component is manufactured by the steps of performing the function/performance design of the component, the step of fabricating the reticle based on the design step, the step of fabricating the wafer from the germanium material, and the above implementation. Form exposure apparatus (pattern forming apparatus) and exposure method thereof, the method of transferring the pattern of the mask (reticle) to the lithography of the wafer, the development step of developing the exposed wafer, and removing the photoresist residue by etching An etching step of the exposed member other than the portion, a photoresist removal step for removing the unnecessary photoresist after etching, a component assembly step (including a cutting step, a bonding step, a packaging step), an inspection step, and the like. In this case, in the lithography step, the exposure method described above is used to perform the above-described exposure method, and the element pattern is formed on the wafer, so that the element having a high degree of integration can be manufactured with good yield.

In addition, the disclosures of all publications, international publications, U.S. Patent Application Publications, and U.S. Patent Specification, which are incorporated herein by reference in its entirety, are incorporated herein by reference.

As described above, the measuring apparatus and measuring method of the present invention are suitable for detecting lattice marks. Further, the exposure apparatus and exposure method of the present invention are suitable for exposing an object. Further, the component manufacturing method of the present invention is suitable for the manufacture of microcomponents.

50‧‧‧Alignment

60‧‧‧Material Optics

62‧‧‧ Objective lens

64‧‧‧Detector side lens

66‧‧‧ lattice board

70‧‧‧ illumination system

72‧‧‧Light source

74‧‧‧ movable mirror

76‧‧‧Half mirror

77‧‧‧ lens

78‧‧‧ Beam position detection sensor

80‧‧‧Lighting system

84‧‧‧Detector

86‧‧‧Optics

86a‧‧‧Mirror

86b‧‧‧Splitter

GM‧‧‧ lattice mark

GMa‧‧‧1st grid mark

GMb‧‧‧2nd grid mark

L1, L2‧‧‧Measurement light

+L3, +L4‧‧‧+1 times of diffracted light

-L3,-L4‧‧‧-1 times of diffracted light

PD1~PD3‧‧‧Photodetector

W‧‧‧ wafer

Claims (26)

A measuring device for measuring position information of a first trellis mark and a second trellis mark which are different in a periodic direction of an object, and includes: a mark detecting system having the object and the first trellis When the mark and the second lattice mark move in a predetermined scanning direction in the different direction of the periodic direction, the first lattice mark and the second lattice mark are irradiated by the objective lens while scanning the measurement light in the scanning direction. And a light receiving system that receives the diffracted light of the measurement light from each of the first lattice mark and the second lattice mark through the objective lens, and an arithmetic processing system that obtains the light receiving result of the diffracted light of the light receiving system The first grid mark and the position information of the second grid mark. The measuring device according to claim 1, wherein the first lattice mark and the second lattice mark are arranged adjacent to each other in a direction intersecting the scanning direction. The measuring device according to claim 1 or 2, wherein the marking detection unit irradiates the first measurement mark with the first measurement light, and irradiates the second lattice mark with the first measurement light. 2 measuring light. The measuring device of claim 3, wherein the marking detection scans the first measuring light and the second measuring light synchronously in the scanning direction. The measuring device of claim 3, wherein the object is movable in parallel with a predetermined two-dimensional plane; the marking detection system is first incident in a plane orthogonal to the lattice line of the first lattice mark The first measurement light is irradiated at an angle, and the second measurement light is irradiated at a second incident angle in a plane orthogonal to the lattice line of the second lattice mark. The measuring device of claim 5, wherein the first incident angle and the second incident angle are the same. The measuring device according to claim 1 or 2, wherein the marking detection system illuminates the first lattice mark and the second lattice mark with at least a portion of the first lattice mark and the second lattice mark The measurement light of the illumination area of at least a portion of the area. The measuring device according to any one of claims 1 to 7, wherein a periodic direction of the first lattice mark and a periodic direction of the second lattice mark are orthogonal to each other; and the scanning direction is relative to the first The periodic direction of the lattice mark and the periodic direction of the second lattice mark are in the direction of an angle of 45°. A measuring device comprising: a mark detecting system having an irradiation system for irradiating the measurement light to the first direction while being arranged in a lattice mark of an object moving in the first direction; and including and capable of moving in the first direction a pair of objective optical systems facing the object optics and a light receiving system that receives the diffracted light from the grating mark through the pair of optical elements; and an arithmetic system based on the detection result of the mark detection system Find the position information of the grid mark. The measuring device of claim 9, wherein the objective optical element is such that the diffracted light generated by the lattice mark is directed toward the objective lens deflected by the light receiving system. An exposure apparatus comprising: the measuring device according to any one of claims 1 to 10; a position control device that controls a position of the object according to an output of the measuring device; and a pattern forming device that irradiates the object with an energy beam Form a predetermined pattern. An exposure apparatus comprising the measuring device according to any one of claims 1 to 10; While controlling the position of the object based on the output of the measuring device, the object is irradiated with an energy beam to form a predetermined pattern on the object. An exposure apparatus for irradiating an object with an energy beam to form a predetermined pattern on the object, comprising: a mark detection system having a first and a first object to be moved in the first direction; The first lattice mark and the second check mark in the periodic direction, which are different in direction and different from each other, receive the illumination system through which the objective light is irradiated while scanning the measurement light in the first direction, and receive the first lattice mark from the objective lens through the objective lens And a light receiving system of the diffracted light of the measurement light in the second lattice mark; and controlling the position of the object based on the detection result of the mark detection system. A method of manufacturing a component, comprising: an action of exposing a substrate using an exposure apparatus according to any one of claims 11 to 13; and an operation of developing the exposed substrate. A measurement method for measuring position information of a first lattice mark and a second lattice mark which are different from each other in a periodic direction of an object, and includes: causing the object to be associated with each of the first lattice marks and the second An operation of moving the predetermined scanning direction in the different direction of the periodic direction of the lattice mark; and when the object moves in the scanning direction, the measurement light is scanned in the scanning direction and transmitted through the first lattice mark and the second lattice mark An operation of irradiating the objective lens; and receiving, by the objective lens, an operation of diffracting light of the measurement light from each of the first lattice mark and the second lattice mark; The operation of determining the position information of the first lattice mark and the second lattice mark based on the light receiving result of the diffracted light. The measuring method of claim 15, wherein the first lattice mark and the second lattice mark are arranged adjacent to each other in a direction intersecting the scanning direction. The measuring method of claim 15 or 16, wherein the irradiating operation is performed by irradiating the first grating mark with the first measuring light, and irradiating the second lattice mark with the first measuring light. The second measurement light. The measuring method of claim 17, wherein the illuminating operation synchronously scans the first measuring light and the second measuring light in the scanning direction. The measuring method of claim 17 or 18, wherein the object is movable in parallel with a predetermined two-dimensional plane; the illuminating action is first incident in a plane orthogonal to the lattice line of the first lattice mark The first measurement light is irradiated at an angle, and the second measurement light is irradiated at a second incident angle in a plane orthogonal to the lattice line of the second lattice mark. The measuring method of claim 19, wherein the first incident angle and the second incident angle are the same. The measuring method of claim 15, wherein the illuminating operation is performed by illuminating the first lattice mark and the second lattice mark with at least a portion of the first lattice mark and the second lattice mark The measurement light of the illumination area of at least a portion of the area. The measuring method according to any one of claims 15 to 21, wherein a periodic direction of the first lattice mark and a periodic direction of the second lattice mark are orthogonal to each other; and the scanning direction is relative to the first The periodic direction of the grid mark and the second lattice mark The direction of the cycle is at an angle of 45°. A measuring method for measuring position information of a lattice mark provided on an object, comprising: an action of moving the object in a first direction; and when the object moves in the first direction, marking the side of the lattice An operation of irradiating the measurement light to the first optical direction while transmitting the optical system; and transmitting, by the optical system, the diffracted light of the measurement light from the lattice mark; and the light receiving system The result of the light reception is the action of obtaining the position information of the grid mark. The measuring method of claim 23, wherein the objective optical element is such that the diffracted light generated by the lattice mark is directed toward the objective lens deflected by the light receiving system. An exposure method comprising: measuring an action of position information of a lattice mark provided on an object using a measurement method according to any one of claims 15 to 24; and controlling the object according to the position information of the grid mark measured The position and the action of exposing the object with an energy beam. A method of manufacturing a component comprising: an action of exposing a substrate using an exposure method of claim 25; and an act of developing the exposed substrate.