JP2011103392A - Exposure device and method, and method for manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure device that adjusts light intensity distribution of a radiated beam to irradiate a mask with, and is conducive to properly forming a pattern on a substrate; and to provide an exposure method and method for manufacturing a device. <P>SOLUTION: The exposure device includes: a light source device that has a plasma generation unit for generating plasma, and a focusing optical system for irradiating a side of an illumination optical system with an exposure light emitted from the plasma; a slit device 24 that adjusts the light intensity distribution of the exposure light which the mask is irradiated with; a measurement device 40 that measures an emission state of the exposure light emitted from the light source device; and a control unit 50 that controls the slit device 24 based on a result measured by the measurement device 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method using the exposure apparatus for forming a predetermined pattern such as a circuit pattern on a substrate.

  In general, an exposure apparatus for manufacturing a microdevice such as a semiconductor integrated circuit includes an illumination optical system that illuminates a mask, such as a reticle, on which a predetermined pattern is formed with exposure light (radiation beam), and exposure light that illuminates the mask. And a projection optical system that projects the image of the mask pattern onto a substrate such as a wafer or a glass plate coated with a photosensitive material. In such an exposure apparatus, a higher resolution of the projection optical system is demanded in order to achieve higher integration of the semiconductor integrated circuit and finer pattern images associated with the higher integration. Therefore, the wavelength of exposure light used in the exposure apparatus has been shortened. In recent years, an exposure apparatus that uses EUV (Extreme Ultraviolet) light as exposure light has been developed (see Patent Document 1).

  Known light source devices capable of emitting EUV light include devices having a laser excitation type plasma light source (LPP) and devices having a discharge excitation type plasma light source (DPP). The EUV light emitted from the light source device is condensed by a condensing optical system having a condensing mirror and then emitted to the illumination optical system.

Japanese Patent Laid-Open No. 11-219900

  By the way, when generating plasma and using EUV light emitted from the plasma as exposure light like a discharge excitation type plasma light source, the generation position and shape (including size) of the plasma in the light source device gradually change. There is a risk. In this case, the exposure light emission state (emission direction, beam diameter, etc.) emitted from the light source device to the illumination optical system changes, and the light intensity distribution of the exposure light emitted from the illumination optical system to the mask in the exposure device changes. There is a risk. As a result, there is a problem that the exposure quality deteriorates such that the light illuminance distribution in the mask irradiated with the exposure light changes and the line width of the pattern formed on the substrate becomes non-uniform.

Such a problem can also occur in an exposure apparatus that uses EUV light emitted from a light source apparatus having a laser-excited plasma light source as exposure light.
The present invention has been made in view of such circumstances, and an object of the present invention is to adjust the light intensity distribution of the radiation beam that irradiates the mask and to contribute to the formation of an appropriate pattern on the substrate. And it is providing the manufacturing method of a device.

In order to solve the above-described problems, the present invention employs the following configuration corresponding to FIGS. 1 to 7 shown in the embodiment.
In the exposure apparatus of the present invention, the radiation beam (EL) is guided to the mask (R) on which a predetermined pattern is formed via the optical system (33) and the illumination optical system (15), and reflected by the mask (R). In an exposure apparatus that exposes a substrate (W) with a radiation beam (EL), a plasma generator (32) that generates plasma (PL) and a radiation beam (EL) radiated from the plasma (PL) into the optical system ( 33) A light source device (12) having an optical system (33) that emits to the illumination optical system (15) side, and an adjustment device that adjusts the light intensity distribution of the radiation beam (EL) irradiated to the mask (R) (24, 64), a measuring device (40) for measuring an emission state of the radiation beam (EL) emitted from the light source device (12), and the adjusting device based on a measurement result by the measuring device (40). (24, And 4) controls the control unit (50), and summarized in that comprises a.

  In the exposure method of the present invention, the radiation (EL) emitted from the light source device (12) is applied to the mask (R) on which a predetermined pattern is formed, and the radiation reflected by the mask (R) is applied. In the exposure method of exposing the substrate (W) with a beam (EL), an emission state of the radiation beam (EL) emitted from the light source device (12) is measured, and the mask is based on the measurement result of the emission state. The gist is to adjust the light intensity distribution of the radiation beam (EL) irradiated to (R).

  According to each of the above configurations, the emission state of the radiation beam (EL) emitted from the light source device (12) is measured, and the light intensity distribution of the radiation beam that irradiates the mask (R) is adjusted based on the measurement result. The That is, the light illuminance distribution on the mask (R) is adjusted. As a result, a pattern is appropriately formed on the substrate (W).

  In order to explain the present invention in an easy-to-understand manner, it has been described in association with the reference numerals of the drawings showing the embodiments, but it goes without saying that the present invention is not limited to the embodiments.

  ADVANTAGE OF THE INVENTION According to this invention, the light intensity distribution of the radiation beam which irradiates a mask can be adjusted, and it can contribute to the suitable pattern formation to a board | substrate.

1 is a schematic block diagram that shows an exposure apparatus according to a first embodiment. The schematic block diagram which shows a light source device. (A) (b) is a schematic block diagram which shows a slit apparatus. FIG. 2 is a block diagram showing the main part of the electrical configuration of the exposure apparatus of the present embodiment. The schematic block diagram which shows the principal part of the illumination optical system of another embodiment. The flowchart of the manufacture example of a device. The detailed flowchart regarding the board | substrate process in the case of a semiconductor device.

(First embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. In this embodiment, the direction parallel to the optical axis of the projection optical system is the Z-axis direction, and the scanning direction of the reticle R and wafer W during scanning exposure in a plane perpendicular to the Z-axis direction is the Y-axis direction. The non-scanning direction orthogonal to the scanning direction is described as the X-axis direction. The rotation directions around the X, Y, and Z axes are also referred to as the θx direction, the θy direction, and the θz direction.

  As shown in FIG. 1, an exposure apparatus 11 according to this embodiment uses extreme ultraviolet light, ie, EUV (Extreme Ultraviolet) light, which is a soft X-ray region having a wavelength of about 100 nm or less, emitted from a light source device 12 as exposure light. It is an EUV exposure apparatus used as an EL. Such an exposure apparatus 11 includes a first chamber 13 (a portion surrounded by a two-dot chain line in FIG. 1) in which the inside is set to a vacuum atmosphere lower in pressure than the atmosphere. The light source device 12 is connected via Further, in the first chamber 13, an illumination optical system 15 that illuminates a reflective reticle R on which a predetermined pattern is formed with the exposure light EL supplied from the light source device 12 into the first chamber 13, and the pattern A reticle stage 16 that holds the reticle R is provided so that the formed pattern formation surface Ra is positioned on the −Z direction side (lower side in FIG. 1). Further, in the first chamber 13, a projection optical system 17 that irradiates a wafer W coated with a photosensitive material such as a resist with exposure light EL through the reticle R, and a wafer surface coated with the photosensitive material. A wafer stage 18 for holding the wafer W is provided so that a certain exposure surface Wa is positioned on the + Z direction side (upper side in FIG. 1).

  The illumination optical system 15 includes a housing 19 (a portion surrounded by a solid line in FIG. 1) in which the interior is set to a vacuum atmosphere, as in the interior of the first chamber 13. A plurality of reflection mirrors (not shown) that can reflect the exposure light EL incident from the light source device 12 into the casing 19 are provided in the casing 19. Then, the exposure light EL sequentially reflected by the respective reflection mirrors is incident on a reflection mirror 20 for folding that is installed in a lens barrel 25 to be described later, and the exposure light EL reflected by the reflection mirror 20 enters the reticle stage 16. It is guided to the held reticle R. A reflective layer, which is a multilayer film in which molybdenum (Mo) and silicon (Si) are alternately laminated, is formed on the reflective surface of each reflective mirror (including the reflective mirror 20 for folding) constituting the illumination optical system 15. Each is formed.

  The reticle stage 16 is disposed on the object plane side of the projection optical system 17 and includes a first electrostatic chuck holding device 21 for electrostatic chucking of the reticle R. The first electrostatic chucking and holding device 21 includes a base 22 made of a dielectric material and having an attracting surface 22a, and a plurality of electrode portions (not shown) disposed in the base 22. When a voltage is applied to each electrode unit from a voltage application unit (not shown), the reticle R is electrostatically adsorbed on the adsorption surface 22 a by the Coulomb force generated from the base body 22.

  The reticle stage 16 can be moved in the Y-axis direction by driving the reticle stage drive unit 23. That is, the reticle stage drive unit 23 moves the reticle R held by the first electrostatic attraction holding device 21 with a predetermined stroke in the Y-axis direction. Further, the reticle stage drive unit 23 can finely move the reticle R in the X-axis direction (direction orthogonal to the paper surface in FIG. 1) and the θz direction.

  Further, a slit device 24 (FIG. 3) for adjusting the light intensity distribution of the exposure light EL that irradiates the pattern forming surface Ra of the reticle R between the reticle stage 16 and a lens barrel 25 of the projection optical system 17 described later. Will be described in detail.). The illumination area formed on the pattern forming surface Ra is formed in a substantially arc shape extending in the X-axis direction, although its shape or position is corrected by driving the slit device 24.

  The projection optical system 17 is an optical system that reduces an image of a pattern formed by illuminating the pattern forming surface Ra of the reticle R with exposure light EL to a predetermined reduction magnification (for example, 1/4). Similar to the inside of one chamber 13, a lens barrel 25 in which the inside is set to a vacuum atmosphere is provided. A plurality of reflection mirrors 26 (six as an example, only one is shown in FIG. 1) are accommodated in the lens barrel 25. Then, the exposure light EL guided from the reticle R side that is the object plane side is sequentially reflected by the mirrors 26 and guided to the wafer W held on the wafer stage 18. A reflective layer, which is a multilayer film in which molybdenum (Mo) and silicon (Si) are alternately stacked, is formed on the reflective surface of each mirror 26.

  The wafer stage 18 includes a second electrostatic suction holding device 27 for electrostatically sucking the wafer W, and the second electrostatic suction holding device 27 is made of a dielectric material and has a suction surface 28a. And a plurality of electrode portions (not shown) arranged in the base 28. When a voltage is applied to each electrode unit from a voltage application unit (not shown), the wafer W is electrostatically adsorbed on the adsorption surface 28 a by the Coulomb force generated from the base 28. Further, the wafer stage 18 has a wafer holder (not shown) for holding the second electrostatic chucking holding device 27 and a Z leveling (not shown) for adjusting the position of the wafer holder in the Z-axis direction and the tilt angles around the X-axis and the Y-axis. And built-in mechanism.

  The wafer stage 18 can be moved in the Y-axis direction by the wafer stage driving unit 29. That is, the wafer stage drive unit 29 moves the wafer W held by the second electrostatic chucking holding device 27 in the Y-axis direction with a predetermined stroke. Further, the wafer stage drive unit 29 can move the wafer W held by the second electrostatic chuck holding device 27 with a predetermined stroke in the X-axis direction and can finely move the wafer W in the Z-axis direction. is there.

  When a pattern of the reticle R is formed on one shot area of the wafer W, the reticle R is moved in the Y-axis direction by driving the reticle stage driving unit 23 in a state where the illumination optical system 15 forms the illumination area on the reticle R. The projection optical system 17 moves the wafer W along the Y-axis direction of the reticle R by moving the wafer W at predetermined strokes (for example, from the + Y direction side to the −Y direction side) and driving the wafer stage drive unit 29. Are moved synchronously in the Y-axis direction (for example, from the −Y direction side to the + Y direction side) at a speed ratio corresponding to the reduction magnification. When the pattern formation on one shot area is completed, the pattern formation on the other shot areas of the wafer W is continuously performed.

Next, the light source device 12 of this embodiment will be described with reference to FIG.
The light source device 12 is a laser excitation type plasma light source device that emits EUV light having a wavelength of 5 to 50 nm (for example, 13.5 nm) as exposure light EL. Specifically, as shown in FIG. 2, the light source device 12 includes a second chamber 30 (indicated by a two-dot chain line in FIG. 2) whose inside is set to a vacuum atmosphere lower in pressure than the atmosphere. In the second chamber 30, a light source unit 31 that outputs the exposure light EL is provided.

The light source unit 31 includes a plasma generation unit 32 that generates the plasma PL, and a condensing optical system 33 that condenses the exposure light EL emitted from the plasma PL. The plasma generating unit 32 includes a nozzle 34 that ejects a high-density tin compound (for example, tin oxide (SnO ₂ )) as an EUV light generating substance (target) at a high speed, and a YAG laser or excimer laser that uses semiconductor laser excitation, for example. And a high output laser 35. The laser beam LR emitted from the high-power laser 35 irradiates a high-density EUV light generating substance ejected from the nozzle 34 at a high speed to generate plasma PL, and EUV light is exposed from the plasma PL. Radiated as light EL. Such exposure light EL enters the condensing optical system 33.

  The condensing optical system 33 has a plurality of cylindrical condensing mirrors 36 (only one is shown in FIG. 2) in which the cross-sectional shape of each position in the Y-axis direction (left-right direction in FIGS. 1 and 2) is an annular shape. The condenser mirrors 36 are arranged so that their axes coincide with each other. In addition, a reflective layer capable of reflecting the exposure light EL is formed on the inner peripheral surface of the condenser mirror 36. The reflective layer of the collector mirror 36 is composed of a multilayer film in which molybdenum (Mo) and silicon (Si) are alternately stacked. Then, the exposure light EL reflected by the condensing mirror 36 is once condensed before entering the illumination optical system 15, and then the reflection located closest to the light source device 12 among the respective reflecting mirrors constituting the illumination optical system 15. Incident on the mirror. A condensing point that is once condensed in the exposure light EL emitted from the condensing mirror 36 is referred to as an “intermediate condensing point IF”.

  Further, in the second chamber 30 of the present embodiment, a measuring device 40 is provided for measuring the generation state of the plasma PL, that is, the generation position and shape (including size). The measuring device 40 includes a plurality of (for example, two) monitoring devices 41, and each of the monitoring devices 41 can observe the position of the plasma PL in the X-axis direction, the Y-axis direction, and the Z-axis direction. Are arranged respectively. For example, the monitor devices 41 are arranged so that their observation axes (indicated by a two-dot chain line in FIG. 2) are orthogonal to each other.

  Each of these monitor devices 41 includes an image sensor 42 composed of a CCD (Charge Coupled Device) image sensor or the like, and a filter member 43 disposed on the plasma PL side of the image sensor 42. Each of these filter members 43 allows transmission of light having a wavelength range used for exposure (in this embodiment, a wavelength range near 13.5 nm) among light of various wavelength components generated by the plasma PL, Each is designed to regulate the transmission of light having a wavelength range unnecessary for exposure. For example, in this embodiment, a filter made of zirconium (Zr) is used as the filter member 43.

  Each imaging element 42 receives light transmitted through the filter member 43 among light generated by the plasma PL. That is, each imaging element 42 can individually image the plasma PL that generates light in the wavelength region used for exposure in the plasma PL. And from each image pick-up element 42, the imaging information according to those light reception results is output to the control apparatus 50 mentioned later.

  Further, the measurement device 40 of the present embodiment is provided with a light amount detection unit 44 (see FIG. 4) for detecting the light amount of the exposure light EL generated from the plasma PL. As an example, the light amount detection unit 44 includes a light receiving element that is disposed in the vicinity of the generation position of the plasma PL and that can detect the energy of light (particularly EUV light) generated from the plasma PL. Then, the light amount detection unit 44 outputs light amount information corresponding to the detection result by the light receiving element to the control device 50.

Next, the slit apparatus 24 of this embodiment is demonstrated based on Fig.3 (a) (b).
The slit device 24 is a device for adjusting the position or shape of an illumination region that is disposed in the vicinity of a position conjugate with the pattern forming surface Ra of the reticle R, that is, the image surface, and formed on the pattern forming surface Ra. As shown in FIG. 3A, the slit device 24 includes a fixed blade 45 arranged on the + Y direction side (right side in FIG. 3A) and a −Y direction side (left side in FIG. 3A). And a plurality of movable blades 46 (12 in FIG. 3A).

  The fixed blade 45 is made of a plate material disposed substantially parallel to the XY plane, and is formed so that a portion on the + Y direction side has a substantially arc shape. Further, the fixed blade 45 can block at least a part of the light incident on the fixed blade 45. Each movable blade 46 is arranged along the X-axis direction orthogonal to the Y-axis direction, which is the scanning direction of the reticle R and the wafer W, respectively. Each movable blade 46 can shield at least a part of the light incident on each movable blade 46.

  In addition, the slit device 24 is provided with a plurality (12 in FIG. 3A) of actuators 47 that individually correspond to the movable blades 46, and each of the actuators 47 responds to a control command from the control device 50. Depending on the drive. Each such actuator 47 is connected to each individually corresponding movable blade 46 via a rod member 48. When each actuator 47 is driven, each movable blade 46 moves individually along the Y-axis direction as shown in FIG. As a result, the shape of the slit (opening) 49 formed by the fixed blade 45 and each movable blade 46 is changed. That is, the light intensity distribution of the exposure light EL that illuminates the pattern forming surface Ra of the reticle R is adjusted, and the shape or position of the illumination region formed on the pattern forming surface Ra is adjusted accordingly.

Next, the main part of the electrical configuration of the exposure apparatus 11 of this embodiment will be described with reference to FIG.
As shown in FIG. 4, each monitor device 41 and the light amount detection unit 44 are electrically connected to an input side interface (not shown) of the control device 50. In addition, the reticle stage drive unit 23, the wafer stage drive unit 29, and each actuator 47 are electrically connected to an output side interface (not shown) of the control device 50. The control device 50 includes a CPU, a ROM, a RAM, a memory, and the like. The control device 50 includes a plasma position measurement unit 51, a memory 52, a slit shape specifying unit 53, a slit control unit 54, and a scan control unit 55 as functional parts respectively realized by at least one of hardware and software. ing.

  Imaging information from each monitor device 41 and light amount information from the light amount detection unit 44 are input to the plasma position measurement unit 51 via an input side interface. Then, the plasma position measuring unit 51 derives the generation position and shape of the plasma PL in the light source device 12 based on the imaging information, and outputs the derived result to the slit shape specifying unit 53. Further, when the light amount information is input, the plasma position measuring unit 51 derives the light amount of the exposure light EL emitted from the light source device 12 based on the light amount information, and outputs the derived result to the slit shape specifying unit 53. .

  In the memory 52, the shape of the slit 49 of the slit device 24 corresponding to the generation position and shape of the plasma PL in the light source device 12 and the amount of the exposure light EL is stored in advance. For example, the shape of the slit 49 corresponding to the case where the light intensity on the −X direction side is weaker than the light intensity on the + X direction side on the pattern forming surface Ra of the reticle R is such that the shape on the + X direction side is smaller than the −X direction side. The shape becomes narrower. Further, when the amount of exposure light EL is small, the interval between the slits 49 is set wider than when the amount of exposure light EL is large. The “interval” here refers to the width in the Y-axis direction.

  When each piece of information is input from the plasma position measuring unit 51, the slit shape specifying unit 53 reads the shape of the slit 49 corresponding to each piece of information from the memory 52. The slit shape specifying unit 53 individually sets the position of each movable blade 46 in the Y-axis direction so that the shape of the slit 49 of the slit device 24 approaches the shape of the slit 49 read from the memory 52. Further, the slit shape specifying unit 53 outputs a control command for individually moving each movable blade 46 to the slit control unit 54, and also controls the command corresponding to the interval between the positions of the set slit 49 in the X-axis direction. Is output to the scan control unit 55.

  The slit controller 54 has a driver circuit (not shown) for driving each actuator 47. When such a control command is input from the slit shape specifying unit 53, the slit control unit 54 individually sets the drive amount of each actuator 47 based on the content of the control command. The slit controller 54 drives each actuator 47 individually based on the set drive amount.

  The scan control unit 55 has a driver circuit (not shown) for driving the reticle stage driving unit 23 and the wafer stage driving unit 29. When such a control command is input from the slit shape specifying unit 53, the scan control unit 55 sets the movement speed of the reticle R and the wafer W along the Y-axis direction according to the control command. Then, during the exposure process on the wafer W, the scan control unit 55 performs the reticle stage driving unit 23 and the wafer stage driving unit 29 so that the reticle R and the wafer W are synchronously moved along the Y-axis direction at the set moving speed. Drive. In this embodiment, the moving speed of the reticle R and the wafer W is set so as to increase as the interval between the slits 49 of the set slit device 24 becomes narrower.

Further, when the exposure to one shot area of the wafer W is completed, the scan control unit 55 moves the wafer W to start the exposure to the next shot area.
Next, the exposure method of this embodiment will be described. In the present embodiment, it is assumed that the shape of the slit 49 of the slit device 24 is adjusted as necessary every time exposure to the shot area is completed. For example, after the exposure to a specific shot area is completed, the light intensity distribution of the exposure light EL that illuminates the reticle R (for example, the exposure light irradiated to the reticle R) while the exposure to the next shot area is started The shape of the EL illumination area is adjusted.

  When the exposure to one shot area (also referred to as the previous shot area) of the wafer W is completed, the shape of the slit 49 of the slit device 24 is adjusted before the exposure to the next shot area is started. The That is, each monitor device 41 images the plasma PL generated by the plasma generation unit 32 during the exposure to the previous shot region, and captures imaging information corresponding to the imaging result of the plasma position measurement unit 51 of the control device 50. Are output respectively. Further, the light quantity detection unit 44 causes the light receiving element to detect the energy of light generated from the plasma PL during exposure to the previous shot area, and outputs light quantity information corresponding to the detection result to the plasma position measurement unit 51, respectively. is doing. Therefore, in the exposure apparatus 11 of this embodiment, it is not necessary to generate the plasma PL regardless of the exposure directly between the exposure to the previous shot area and the exposure to the next shot area.

  Then, between the exposure to the previous shot area and the exposure to the next shot area, the plasma position measurement unit 51 derives the generation position and shape of the plasma PL based on each imaging information from each monitor device 41. At the same time, the slit shape specifying unit 53 sets the position of each movable blade 46 of the slit device 24 in the Y-axis direction. Further, the scan control unit 55 sets the movement speeds of the reticle R and the wafer W at the time of exposure to the next shot area.

  The light irradiation amount at each position on the pattern forming surface Ra of the reticle R is an integrated value of the light irradiation amount per unit time. Therefore, it is desirable to set the time (irradiation time) irradiated with the exposure light EL for each position in the X-axis direction (that is, the direction orthogonal to the scanning direction) of the pattern forming surface Ra. Therefore, in the present embodiment, the movable blade 46 corresponding to the position where the light irradiation amount is estimated to be small before the shape of the slit 49 is corrected is less than the position at the time of exposure to the previous shot area. Move to the Y direction. On the other hand, the movable blade 46 corresponding to the position where the amount of light irradiation is estimated to be large before the shape of the slit 49 is corrected moves to the + Y direction side from the position at the time of exposure to the previous shot area. . That is, the irradiation time at each position in the X-axis direction of the pattern formation surface Ra is individually adjusted according to the amount of light irradiation before the shape of the slit 49 is corrected.

  When the next shot area is exposed after the shape of the slit 49 is corrected, the light irradiation amount at each position on the pattern forming surface Ra of the reticle R becomes substantially equal. As a result, even at each position of the next shot area of the wafer W, the light irradiation amount (that is, the exposure amount) becomes substantially equal. For this reason, in the next shot region, the occurrence of exposure failure due to the exposure light EL wraparound and the exposure light EL light quantity shortage is suppressed.

  In general, as a method of correcting the light intensity distribution of the exposure light EL that irradiates the reticle R, an irradiated member is arranged in the optical path of the exposure light EL, and the irradiated area formed on the irradiated member is defined as a CCD image sensor. There is known a method of observing with an observation unit having the above. In such a method, since it is necessary to move the irradiated member in the optical path of the exposure light EL, it is performed between the exposure to the previous shot area and the exposure to the next shot area in one wafer W. This is not desirable because of the throughput of the exposure apparatus 11. Therefore, the above method is often performed during the exchange of the wafer W to be exposed. In such a case, when the generation position or shape of the plasma PL changes in the light source device 12 during exposure of one wafer W, the exposure for illuminating the reticle R until the next wafer W is replaced. It is difficult to correct the light intensity distribution of the light EL.

  Further, even if the light intensity distribution of the exposure light EL that irradiates the reticle R during the exposure of one wafer W is corrected, the change in the light intensity distribution of the exposure light EL that irradiates the reticle R is estimated, Based on the estimation result, the light intensity distribution of the exposure light EL is corrected. In this case, there is room for improvement in improving the correction accuracy of the light intensity distribution of the exposure light EL.

  In this regard, in the present embodiment, the state of generation of the plasma PL during the exposure to the previous shot region, the energy of light generated from the plasma PL, and the like are measured, and the exposure light EL that irradiates the reticle R based on the measurement result is measured. Changes in the light intensity distribution are measured. Then, the light intensity distribution of the exposure light EL that irradiates the reticle R is corrected between the exposure to the previous shot area and the exposure to the next shot area. Therefore, as compared with the case of correcting the light intensity distribution of the exposure light EL based on the estimation as described above, the correction accuracy is improved because the light intensity distribution of the exposure light EL is corrected based on the actual measurement. .

Therefore, in this embodiment, the following effects can be obtained.
(1) The exposure light EL emitted from the light source device 12 is measured during the exposure of one wafer W, and the light intensity of the exposure light EL that irradiates the reticle R based on the measurement result. Distribution is adjusted. As a result, the light intensity distribution formed on the reticle R illuminated with the exposure light EL can be suitably adjusted. Therefore, even if the generation state of the plasma PL changes in the light source device 12 during the exposure to the wafer W, the light intensity distribution of the exposure light EL that irradiates the reticle R during the exposure to the wafer W is adjusted. This can contribute to the formation of an appropriate pattern on the wafer W.

  (2) In the present embodiment, the light intensity distribution of the exposure light EL that irradiates the reticle R is quickly adjusted between the exposure to the previous shot area and the exposure to the next shot area. That is, the light intensity distribution of the exposure light EL that irradiates the reticle R is adjusted for each shot region. Therefore, the non-defective product rate in each shot region in one wafer W can be improved as compared with the case where the light intensity distribution of the exposure light EL that irradiates the reticle R to each wafer W is adjusted.

  (3) In the present embodiment, the shape of the illumination area of the reticle R is corrected by individually adjusting the position of each movable blade 46 in the Y-axis direction of the slit device 24 disposed in the vicinity of the reticle R. Therefore, by precisely adjusting the position of each movable blade 46 in the Y-axis direction, the light irradiation amount at each position in the X-axis direction of the pattern forming surface Ra of the reticle R can be made substantially uniform. Therefore, the non-defective product rate in each shot area in one wafer W can be improved.

  (4) Further, the moving speed at the time of exposure of the reticle R and the wafer W is set to a speed corresponding to the interval between the slits 49 of the slit device 24. Therefore, it is possible to contribute to forming an appropriate pattern on each shot area of the wafer W.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the second embodiment, the configuration of the exposure apparatus 11 is the same as that of the first embodiment, but the exposure method is different from that of the first embodiment. Therefore, in the following description, parts different from those of the first embodiment will be mainly described, and the same or corresponding member configurations as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. Shall.

  The exposure method of this embodiment is slightly different from the exposure method of the first embodiment, and is a method of adjusting the light intensity distribution of the exposure light EL that illuminates the reticle R during exposure of one shot area of the wafer W. It is.

  That is, in the light source device 12, each monitor device 41 captures the position and shape of generation of the plasma PL, and the light receiving element of the light amount detection unit 44 is generated from the plasma PL even during exposure to one shot region. Detect the energy of the light to be. Therefore, in the control device 50, the optimum shape of the slit 49 of the slit device 24 at that time is set as needed by the slit shape specifying unit 53. Based on the newly set shape of the slit 49, the positions of the movable blades 46 in the Y-axis direction are individually adjusted, and the moving speeds of the reticle R and the wafer W are adjusted.

Therefore, in this embodiment, in addition to the effects (1), (3), and (4) of the first embodiment, the following effects can be obtained.
(5) In this embodiment, the light intensity distribution of the exposure light EL that irradiates the reticle R is adjusted even during exposure of one shot region. That is, the illumination condition of the reticle R is corrected in response to a change in the light intensity distribution of the exposure light EL that irradiates the reticle R. Therefore, a pattern can be appropriately formed in each shot area.

In addition, you may change each said embodiment into another embodiment as follows.
In each embodiment, three or more arbitrary numbers (for example, five) of monitor devices 41 may be provided. However, it is desirable to arrange the monitor devices 41 at different positions in the circumferential direction centering on the ideal plasma PL generation position.

  In the first embodiment, the measurement by the measurement device 40 is performed by generating the plasma PL in the light source device 12 for measurement after the exposure to the previous shot area is completed, and measuring the generated plasma PL. There may be.

  In each embodiment, the slit device 24 may be disposed in the illumination optical system 15 on the light source side or the reticle R side with respect to the position conjugate with the pattern forming surface Ra of the reticle R. Even if comprised in this way, the effect equivalent to said (1) can be acquired.

  In each embodiment, the slit device 24 may have a configuration including an arbitrary light shielding portion as long as it is a light shielding portion capable of shielding at least a part of the incident exposure light EL. For example, the light shielding portion may be a tube (for example, an optical waveguide or an optical fiber for EUV light) whose inner peripheral surface can absorb exposure light EL (EUV light).

  In each embodiment, as a method of changing the shape and position of the exposure light EL that illuminates the reticle R, any other method other than correcting the shape of the slit 49 may be used. For example, as shown in FIG. 5, a plurality of (four in FIG. 5) mirrors 60, 61, 62, 63 including a pair of fly-eye mirrors 61, 62 are provided in the housing 19 of the illumination optical system 15. Is provided. A displacement mechanism 64 for displacing some of the mirrors 60 to 63 (for example, the mirror 60) is provided. Then, at least one of the shape and position of the exposure light EL that irradiates the reticle R may be changed by displacing the mirror 60 by driving the displacement mechanism 64. Even if comprised in this way, the effect equivalent to said (1) can be acquired. In this case, the slit device 24 may be a fixed slit device instead of the movable type as in the above embodiments.

  In each embodiment, the plasma position measurement unit 51 derives the generation position and shape of the plasma PL, but derives either the generation position or shape of the plasma PL, and slits based on the derivation result. The shape specifying unit 53 may calculate the shape of the slit 49.

  In the illumination optical system 15, a correction filter and a light shielding member may be provided in the vicinity of a position conjugate with the pattern forming surface Ra of the reticle R (that is, an image plane conjugate position). In this case, as the correction filter, filters having different transmittances depending on the position where the exposure light EL is incident may be used, or filters having different transmittances may be used depending on the incident angle of the exposure light EL. . The light intensity distribution of the exposure light EL can be adjusted by displacing the correction filter based on the imaging result of each monitor device 41 and the detection result of the light amount detection unit 44. As a result, the same effect as the above (1) can be obtained.

  Further, when using the light shielding member, the light of the exposure light EL is adjusted by adjusting the installation position of the light shielding member in the optical path of the exposure light EL based on the imaging result of each monitor device 41 and the detection result of the light quantity detection unit 44. The intensity distribution can be adjusted. As a result, the same effect as the above (1) can be obtained.

  In the case of such a configuration, the slit device 24 may be a fixed slit device instead of the movable type as in the above embodiments. The correction filter and the light shielding member are desirably arranged on the light source device 12 side or the reticle R side from the image plane conjugate position.

  In each embodiment, the exposure apparatus 11 manufactures a reticle or mask used in not only a microdevice such as a semiconductor element but also a light exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, and an electron beam exposure apparatus. Therefore, an exposure apparatus that transfers a circuit pattern from a mother reticle to a glass substrate or a silicon wafer may be used. The exposure apparatus 11 is used for manufacturing a display including a liquid crystal display element (LCD) and the like, and is used for manufacturing an exposure apparatus that transfers a device pattern onto a glass plate, a thin film magnetic head, and the like. It may be an exposure apparatus that transfers to a wafer or the like, and an exposure apparatus that is used to manufacture an image sensor such as a CCD.

  In each embodiment, the EUV light generating material used in the light source device 12 may be gaseous tin (Sn), or liquid or solid tin. Xenon (Xe) may be used as the EUV light generating substance.

In each embodiment, the light source device 12 may be a device having a discharge plasma light source.
In each embodiment, the exposure apparatus 11 may be embodied as a step-and-repeat apparatus. In this case, as a method of correcting the light intensity distribution of the exposure light EL that illuminates the reticle R, at least one of the mirrors constituting the illumination optical system 15 is displaced, or in the vicinity of a position conjugate with the image plane. A correction filter or a light-shielding member may be arranged on the screen. As the correction filter, filters having different transmittances according to the position where the exposure light EL is incident may be used, or filters having different transmittances may be used according to the incident angle of the exposure light EL.

  Next, an embodiment of a microdevice manufacturing method using the device manufacturing method by the exposure apparatus 11 of the embodiment of the present invention in the lithography process will be described. FIG. 6 is a flowchart showing a manufacturing example of a micro device (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micro machine, etc.).

  First, in step S101 (design step), function / performance design (for example, circuit design of a semiconductor device) of a micro device is performed, and pattern design for realizing the function is performed. Subsequently, in step S102 (mask manufacturing step), a mask (reticle R or the like) on which the designed circuit pattern is formed is manufactured. On the other hand, in step S103 (substrate manufacturing step), a substrate (a wafer W when a silicon material is used) is manufactured using a material such as silicon, glass, or ceramics.

  Next, in step S104 (substrate processing step), using the mask and substrate prepared in steps S101 to S104, an actual circuit or the like is formed on the substrate by lithography or the like, as will be described later. Next, in step S105 (device assembly step), device assembly is performed using the substrate processed in step S104. Step S105 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary. Finally, in step S106 (inspection step), inspections such as an operation confirmation test and a durability test of the microdevice manufactured in step S105 are performed. After these steps, the microdevice is completed and shipped.

FIG. 7 is a diagram illustrating an example of a detailed process of step S104 in the case of a semiconductor device.
In step S111 (oxidation step), the surface of the substrate is oxidized. In step S112 (CVD step), an insulating film is formed on the substrate surface. In step S113 (electrode formation step), an electrode is formed on the substrate by vapor deposition. In step S114 (ion implantation step), ions are implanted into the substrate. Each of the above steps S111 to S114 constitutes a pretreatment process at each stage of the substrate processing, and is selected and executed according to a necessary process at each stage.

  When the above-mentioned pretreatment process is completed in each stage of the substrate process, the posttreatment process is executed as follows. In this post-processing process, first, in step S115 (resist formation step), a photosensitive material is applied to the substrate. Subsequently, in step S116 (exposure step), the circuit pattern of the mask is transferred to the substrate by the lithography system (exposure apparatus 11) described above. Next, in step S117 (development step), the substrate exposed in step S116 is developed to form a mask layer made of a circuit pattern on the surface of the substrate. Subsequently, in step S118 (etching step), the exposed member other than the portion where the resist remains is removed by etching. In step S119 (resist removal step), the photosensitive material that has become unnecessary after the etching is removed. That is, in step S118 and step S119, the surface of the substrate is processed through the mask layer. By repeatedly performing these pre-processing steps and post-processing steps, multiple circuit patterns are formed on the substrate.

  DESCRIPTION OF SYMBOLS 11 ... Exposure apparatus, 12 ... Light source device, 15 ... Illumination optical system, 23 ... Reticle stage drive part which comprises movement apparatus, 24 ... Slit apparatus as adjustment apparatus, 29 ... Wafer stage drive part which comprises movement apparatus, 32 DESCRIPTION OF SYMBOLS ... Plasma generating part, 33 ... Condensing optical system, 40 ... Measuring apparatus, 46 ... Movable blade | wing as a light-shielding part, 47 ... Actuator, 50 ... Control apparatus, 64 ... Displacement mechanism as adjustment apparatus, EL ... Exposure as radiation beam Light, PL ... plasma, R ... reticle as mask, W ... wafer as substrate.

Claims (12)

In an exposure apparatus that guides a radiation beam to a mask on which a predetermined pattern is formed via an illumination optical system and exposes a substrate with the radiation beam reflected by the mask,
A light source device having a plasma generator for generating plasma and an optical system for emitting a radiation beam emitted from the plasma to the illumination optical system side;
An adjusting device for adjusting the light intensity distribution of the radiation beam irradiated on the mask;
A measuring device for measuring an emission state of the radiation beam emitted from the light source device;
An exposure apparatus comprising: a control device that controls the adjustment device based on a measurement result obtained by the measurement device. The exposure apparatus according to claim 1, wherein the adjustment device adjusts at least one of a shape and a position of the radiation beam irradiated on the mask. A moving device for synchronously moving the mask and the substrate in a predetermined scanning direction;
The adjusting device is arranged along a crossing direction intersecting the scanning direction, and a plurality of light shielding parts capable of shielding a part of the radiation beam, and the plurality of light shielding parts move forward and backward along the scanning direction. The exposure apparatus according to claim 2, further comprising a plurality of actuators. The said control apparatus controls the said adjustment apparatus based on the measurement result by the said measuring apparatus, before the said radiation beam through the said mask irradiates the said board | substrate. The exposure apparatus according to any one of the above. The controller controls the adjustment device based on a measurement result by the measurement device after irradiating the first shot region of the substrate with the radiation beam through the mask and before irradiating the second shot region of the substrate. The exposure apparatus according to any one of claims 1 to 3, wherein the exposure apparatus is controlled. The control device moves the mask and the substrate synchronously in the scanning direction by the moving device, and irradiates the substrate with the radiation beam through the mask, based on a measurement result by the measurement device. The exposure apparatus according to claim 3, wherein the adjustment apparatus is controlled. The exposure apparatus according to claim 1, wherein the measurement apparatus measures a generation state of plasma in the plasma generation unit. In an exposure method of irradiating a mask on which a predetermined pattern is formed with a radiation beam emitted from a light source device and exposing the substrate with the radiation beam reflected by the mask,
Measure the emission state of the radiation beam emitted from the light source device,
An exposure method comprising adjusting a light intensity distribution of the radiation beam applied to the mask based on a measurement result of the emission state. The exposure method according to claim 8, wherein the adjustment of the light intensity distribution is performed before the substrate is irradiated with a radiation beam. 9. The exposure method according to claim 8, wherein the measurement of the emission state of the radiation beam and the adjustment of the light intensity distribution are performed while the substrate is irradiated with the radiation beam. The exposure according to any one of claims 8 to 10, wherein the light intensity distribution is adjusted by adjusting at least one of a shape and a position of the radiation beam irradiated on the mask. Method. In a device manufacturing method including a lithography process,
The device manufacturing method according to claim 1, wherein the lithography process uses the exposure apparatus according to claim 1.

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