JPH10270349A - Substrate transferring device and exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly stabilize the floating state of a reticle substrate in a horizontal state during the micromotion-positioning of the substrate by performing feedback control for offsetting the inclination, floating amount, and residual vibration of the substrate in the vertical floating direction. SOLUTION: A substrate transferring device is used as a reticle stage 1 and a reticle hand which exchanges reticle substrates 2 mounted on the stage 1. An X-direction actuator and a sensor 26 which is a Z-direction (floating direction) position (gap) detecting means are provided on the main body 17 of a transportation handle in a substrate transporting moving section 19 and the horizontal inclination, floating amount, and vibration of the substrate 2 and the displacement component of the substrate 2 in the Z-direction caused by resonance and detected from the sensor 26. Then feedback control is performed for offsetting error components and disturbance by means of the actuator. In this control, the controllability can be improved further by giving a vibration damping function to a plate spring 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer device for transferring a substrate such as a reticle or a semiconductor wafer, and more particularly to a transfer device for transferring a substrate to an exposure stage used in an exposure device. The present invention relates to a substrate transfer apparatus capable of performing positioning and an exposure apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, in an exposure apparatus (stepper) of a batch exposure system, when a projection optical system is constituted by a lens, an image forming area has a circular shape. However, since the semiconductor integrated circuit generally has a rectangular shape, the transfer area in the case of batch exposure is a rectangular area inscribed in a circular imaging area of the projection optical system. Therefore, even the largest transfer area is a square of 1 / √2 of the diameter of the circle.

On the other hand, the transfer is performed by synchronizing and scanning the reticle and the wafer by using a slit-shaped exposure area having a diameter substantially equal to the diameter of the circular imaging area of the projection optical system. A scanning exposure method (step-and-scan method) for enlarging an area has been proposed. In this method, when using a projection optical system having an image forming area of the same size, collective exposure can be performed for each transfer area larger than in the step-and-repeat method using a projection lens. In other words, since there is no restriction by the optical system in the scanning direction, it is possible to secure only the stroke of the scanning stage, and it is possible to secure a transfer area of approximately √2 times in the direction perpendicular to the scanning direction. .

In an exposure apparatus for manufacturing a semiconductor integrated circuit, an enlargement of a transfer area and an improvement in resolution are desired in order to cope with the manufacture of a highly integrated chip. The fact that a smaller projection optical system can be employed is advantageous from the viewpoint of optical performance and cost, and the exposure method of the step-and-scan method is attracting attention as a mainstream of future exposure apparatuses. In such a step-and-scan exposure apparatus, it is necessary to align the reticle and the wafer with high precision.For example, the reticle mounted on the reticle stage by reticle exchange or the like is a reference mark of the reticle stage by a reticle alignment scope. Is measured with high accuracy. In this reticle scope, the higher the accuracy, the narrower the measurement range, and the measurement range of the reticle alignment scope in an exposure apparatus compatible with a 256-Mbit D-RAM is about 2 μm. With the conventional reticle hand, it was impossible to mount the reticle on the reticle stage with an error of about 2 μm. Therefore, it is conceivable to provide an XYθ fine movement mechanism on the reticle stage and switch the reticle alignment scope to a low magnification to drive the reticle displacement to within 2 μm. However, if the XYθ fine movement mechanism is provided on the reticle stage, the reticle stage becomes heavy, and especially in an exposure apparatus that scans the reticle, the stage base is distorted due to the weight of the stage, and problems such as a decrease in exposure accuracy occur.

[0005] In order to solve the problem, Japanese Patent Application No. 8-257365 filed by the present applicant (hereinafter referred to as a prior application) has been proposed.
As shown in FIGS. 17 to 19, in a substrate transfer apparatus having a transfer hand 114 for transferring a substrate 102 and transferring it to the movable stage 101, the substrate 102 is placed in a mechanism of the transfer hand 114. Fine movement mechanism 115 for finely moving within the pattern drawing surface and around an axis perpendicular to the drawing surface.
As shown in FIG. 19, the transfer hand 114 is capable of moving in the horizontal and vertical directions.
7 and a substrate suction portion 120 which is elastically supported in the vertical direction by a leaf spring 118 with respect to the main body and holds the substrate 102 substantially horizontally. As described above, at the substrate transfer position with the exposure stage 101 which is a movable stage by the linear motor 103, the transport hand 114 is lowered vertically to contact or press the substrate 102 against the air pad 124 on the exposure stage 101. It has been proposed that air is blown out from an air pad to float the substrate 102 by a very small amount, and the substrate is finely moved by the fine movement mechanism to position the substrate.

[0006] However, the substrate 102 supported by the elastically supported substrate adsorbing section 120 is provided on the air pad 1.
When the air floats due to 24, residual vibration and tilt of the board at the time of the floating occur, and it takes time until the board finally floats in the horizontal direction and reaches a stationary state, during which time it is observed with the alignment scopes 125a and 125b. However, there is a drawback that the above-described fine movement positioning cannot be stably performed, or the fine movement positioning accuracy is reduced.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior application, and it is intended to reduce the floating state fluctuation and floating amount error of a substrate which has been air-floated by an air pad when positioning the substrate. A substrate transfer device capable of correcting and controlling, stabilizing the substrate in a horizontal state quickly with respect to a target flying height, and improving the total throughput and exposure accuracy of the device when the substrate transfer device is used in an exposure device; and An object of the present invention is to provide an exposure apparatus.

[0008]

In order to achieve the above object, a substrate transfer apparatus according to the present invention provides a transfer hand for transferring a substrate to a movable stage having an air pad, and a mechanism of the transfer hand. A fine movement mechanism for finely moving the substrate within a pattern drawing plane drawn on the substrate surface and around an axis perpendicular to the plane, and a transfer movable in the horizontal and vertical directions constituting the transfer hand A hand main body and a substrate suction unit that is elastically supported in a vertical direction with respect to the main body and holds the substrate horizontally; a unit that detects a floating amount of the substrate from the air pad; An actuator for driving each of the substrate suction portions in a vertical direction, and a transfer hand main body portion being lowered in a vertical direction at a substrate transfer position with the movable stage so that the substrate is moved forward. An output of the detection means when the substrate is positioned by contacting or pressing against an air pad on the movable stage and blowing air from the air pad to float the substrate by a small amount and finely moving the substrate by the fine movement mechanism. Driving the actuator based on
And a control unit for performing at least one of the inclination correction, the flying height correction, and the vibration suppression of the substrate.

Further, the exposure apparatus of the present invention has an exposure stage and a transfer hand for transferring the substrate and transferring it to the exposure stage, and the substrate substrate is drawn on the substrate surface in a mechanism of the transfer hand. A fine movement mechanism is provided for finely moving in the pattern drawing plane and around an axis perpendicular to the plane, and the transfer hand is movable vertically and horizontally with respect to the transfer hand main body and the transfer hand main body. A substrate transfer device constituted by a plurality of substrate suction units elastically supported and holding the substrate horizontally, and at a substrate transfer position between the transfer hand and the exposure stage, the transfer hand is lowered vertically to The substrate is contacted or pressed against an air pad on the exposure stage, and air is blown out from the air pad to float the substrate by a small amount, and the fine movement mechanism is used. Means for detecting the amount of floating of the substrate from the air pad when finely moving the substrate and positioning the substrate, means for vertically driving the elastically supported substrate suction portion, and the detection means And a control means for performing at least one of correction of a tilt error of the substrate, correction of a flying height error, and suppression of vibration using a driving means.

The flying height detecting means may directly measure the distance between the substrate sucked by the substrate sucking portion and the air pad. It may measure a gap with the movable stage. Further, it is preferable that the elastic support portion for supporting the substrate suction portion with respect to the transfer hand main body portion is formed of an elastic support member formed by laminating a metal plate spring and a viscoelastic member in a single layer or a plurality of layers.

The control means of the exposure apparatus performs the error correction or the vibration suppression by performing feedback control on the air pressure and flow rate blown out from the air pad based on the output of the detection means. Further, an actuator for driving each of the substrate suction portions in a vertical direction with respect to the transport hand main body is provided, and the control means performs feedback control of both the air pressure and the flow rate and feedback control of the actuator. In that case, the control means mainly corrects the flying height and inclination of the substrate by feedback control of the air pressure and flow rate blown out from the air pad based on the output of the detection means, and performs feedback control of the actuator by feedback control of the actuator. The residual vibration during the floating may be suppressed, or the feedback drive control of the actuator and the feedback control of the air pressure and the flow rate may be performed by dividing the control band frequency.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A substrate transfer apparatus according to one embodiment of the present invention includes an elastically supported substrate in a mechanism of a transfer hand that transfers the substrate and transfers it to a movable stage (exposure stage) of the exposure apparatus. A means for detecting a gap displacement between the substrate suction unit to be sucked and the main body of the transfer hand or a gap between the substrate suction unit and the movable stage of the exposure apparatus, and an electromagnetic device for driving the elastically supported substrate suction unit in the vertical floating direction. Providing an actuator and a servo valve for controlling the pressure and flow rate of the levitation air of the substrate, and detecting the inclination of the substrate during levitation, the amount of levitation and residual vibration during levitation by the detection means,
The electromagnetic actuator and the floating air control means including a servo valve perform feedback control for canceling the inclination occurring on the substrate, the floating deviation with respect to the target floating amount, and the residual vibration.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an appearance of an exposure apparatus according to an embodiment of the present invention, and FIG. 2 is a view schematically showing a state of the exposure apparatus viewed from a side. As shown in these figures,
The exposure apparatus projects a part of the pattern of a reticle substrate 2 on a reticle stage 1 onto a wafer 4 on a wafer stage 5 via a projection optical system 10, and projects the reticle substrate relative to the projection optical system 10. By synchronously scanning the wafer 2 and the wafer 4 in the Y direction, the pattern of the reticle substrate 2 is exposed on the wafer 4 on the wafer stage 5, and this scanning exposure is performed on a plurality of transfer areas (shots) on the wafer 4. This is a step-and-scan type exposure apparatus that performs the movement while interposing a step movement for repeated execution.

The reticle stage 1 is driven in the Y direction by a linear motor 3, the X stage of the wafer stage 5 is driven in the X direction by a linear motor 5B, and the Y stage is driven in the Y direction by a linear motor 5C. I have. In the synchronous scanning of the reticle substrate 2 and the wafer 4, the reticle stage 1 and the Y stage are driven in the Y direction at a constant speed ratio (for example, 4: -1, where "-" indicates that the directions are opposite). It does by doing.
The step movement in the X direction is performed by the X stage. The X stage is provided with a Z stage 5A for moving in the Z direction, adjusting θ around the Z axis, and chucking the wafer. The wafer stage 5 includes a stage surface plate 6
The stage base 6 is provided on the base frame 7 with high precision and horizontally. Reticle stage 1
Further, the projection optical system 10 is provided on a lens barrel base 9, and the lens barrel base 9 is attached to a base frame 7 installed on a floor or the like by three times.
It is supported via two dampers 8. The damper 8 is an active damper for actively damping or isolating disturbance from the floor or the like via the base frame 7 in six axial directions. A passive damper may be used, or the damper 8 may be supported without a damper. You may.

This exposure apparatus is provided with a laser interferometer 12 for measuring the distance between the lens barrel base 9 and the stage base 6 at a plurality of locations. Further, a focus sensor 11 (1) for detecting whether or not the wafer 4 on the wafer stage 5 is positioned on a focus surface of the projection optical system 10
1A, 11B) are provided. That is, the light is radiated to the wafer 4 from an oblique direction by the light projecting means 11A fixed to the lens barrel base 9 and the position of the reflected light is detected by the light receiving means 11B, whereby the optical axis of the projection optical system 10 is detected. The position of the wafer surface in the direction is detected.

Further, as shown in FIG. 2, light emitted from a laser interferometer light source (not shown) is introduced into a reticle stage Y-direction laser interferometer 13. Then, the light introduced into the Y-direction laser interferometer 13 is transmitted to the laser interferometer 13 by a beam splitter (not shown) in the laser interferometer 13.
Light toward a fixed mirror (not shown) inside the reticle stage 1
And light directed toward a Y-direction moving mirror (not shown) fixed to the light source. Light traveling to the Y-direction moving mirror enters the Y-direction moving mirror through the Y-direction length measuring optical path. The light reflected here returns to the beam splitter in the laser interferometer 13 again through the Y-direction optical path, and is superimposed on the light reflected by the fixed mirror. The movement distance in the Y direction is measured by detecting a change in light interference at this time. The moving distance information measured in this way is fed back to a scanning control device (not shown), and positioning control of the scanning position of the reticle stage 1 is performed. Similarly, the Y stage of the wafer stage 5 also has a Y-direction laser interferometer 13 for the wafer stage.
Positioning control of the scanning position is performed based on the length measurement result by B.

With the above arrangement, the wafer 4 is loaded onto the wafer stage 5 via the transfer path on the front surface of the apparatus by the wafer transfer means (not shown), and when the predetermined alignment is completed, the exposure apparatus performs the scanning exposure and the step While repeating the movement, the pattern of the reticle substrate 2 is exposed and transferred to a plurality of exposure areas on the wafer 4. At the time of scanning exposure, the reticle stage 1 and the Y stage are moved at a predetermined speed ratio in the Y direction (scanning direction) to scan the pattern on the reticle substrate 2 with slit-like exposure light, and to project a projected image thereof. By exposing the wafer 4 to a predetermined exposure area on the wafer 4, the pattern on the reticle substrate 2 is exposed. During the scanning exposure, the height of the surface of the wafer 4 is measured by the focus sensor 11, and the height and the tilt of the wafer stage 5 are controlled in real time based on the measured values, thereby performing focus correction. When the scanning exposure for one exposure area is completed, the X stage is driven in the X direction to move the wafer stepwise, thereby positioning the other exposure area with respect to the scanning exposure start position,
A scanning exposure is performed. The combination of the step movement in the X direction and the movement for scanning exposure in the Y direction allows each of the exposure areas on the wafer 4 to be sequentially and efficiently exposed. , The scanning direction of either positive or negative Y, the order of exposure to each exposure area, and the like are set.

FIGS. 3 to 7 show the configuration of a substrate transfer apparatus according to an embodiment of the present invention. This substrate transfer device is used as a reticle hand for exchanging the reticle stage 1 and the reticle substrate 2 mounted on the reticle stage 1 in the device of FIG.

3 to 7, 1 is a reticle stage (exposure stage), 3 is a reticle stage linear motor, 14 is a transfer hand, 15 is a fine movement mechanism in the XY plane, 1
6 is a linear motor for moving the transfer hand 14 in the Y direction, 17 is a transfer hand main body, 18 is a leaf spring, 19 is a substrate transfer movable portion elastically supported by the plate spring 18 with respect to the transfer hand main body 17, 20 is a substrate suction unit that clamps the reticle substrate 2 during transport and fine movement positioning,
Reference numerals 21A and 21B denote actuator yokes that electromagnetically drive the substrate transfer movable portion 19 elastically supported by the transfer hand main body 17 in the Z direction. Yoke 21A, 2
1B are provided on both sides of the substrate transfer movable section 19 on the transfer hand main body 17. Reference numerals 22A and 22B denote magnets attached to the yokes 21A and 21B to form a magnetic circuit. The magnets 22A and 22B are joined to the respective yokes 21A and 21B. 23
Reference numerals A and 23B denote coils adhered and fixed to the elastically supported substrate transfer movable portion 19, and when a control current is passed through the coil, a magnetic driving force is generated in a gap portion of the magnetic circuit, thereby causing the substrate transfer movable. The unit 19 is driven in the Z direction. 2
4a to 24d are air pads that float the reticle substrate 2 at the time of alignment, and clamp the reticle substrate 2 on the reticle stage 1 after positioning, and 25a and 25b position the reticle substrate 2 with high precision relative to a reticle reference mark. Reticle alignment scope (position detection microscope). 26 is a sensor for detecting a gap between the substrate transfer movable section 19 and the transfer hand main body 17;
The substrate transfer movable portion 19 is formed of aluminum or the like, and the gap is detected by using a capacitance sensor or the like.

In the configuration of the reticle substrate transfer apparatus described above, when a substrate is replaced, a new reticle substrate 2 is first suction-held by a substrate suction unit 20 mounted on the transfer hand 14 by a reticle library or a reticle changer (not shown). In this state, it is located at the retracted position from reticle stage 1 shown in FIGS. Next, the reticle substrate 2 is moved by the linear motor 16 together with the transfer hand 14 to the position shown in FIGS. 3B and 4B, that is, on the reticle stage 1 (FIG. 7A), and the substrate transfer mechanism. The reticle substrate 2 is lowered to a position where it contacts the air pads 24a to 24d on the reticle stage 1 by the Z mechanism of the section (FIG. 7B). After that, the leaf spring 18 supporting the reticle substrate 2 is further elastically deformed by a small amount (FIG. 7C). And the air pad 24
Air is blown out from the air pads 24a to 24d, and the reticle substrate 2 is floated slightly from the air pads 24a to 24d by the air flow (FIG. 7D).

Here, the above-mentioned prior application (Japanese Patent Application No. 8-257) is disclosed.
365), the air pads 24a to 24a
The reticle substrate 2 which has floated by the air from 4d floats together with the elastically supported substrate transporting movable portion 19, so that immediately after the start of the floating, the vibration showing the transient characteristic shown by the curve a in FIG. However, it converged to a predetermined target flying height. 8A and 8B, the vertical axis represents the reticle floating amount Z (μm), and the horizontal axis represents the elapsed time T (second) from the start of floating. As described above, the substrate transporting movable portion and the reticle substrate only supporting the leaf spring of the prior application show the floating transient characteristic shown by the curve a, and the elastic supporting system and the instability element of the air floating (displacement of the flow rate and pressure balance) immediately after the floating. As a result, it took a certain time for the vibration to attenuate and converge to a stable floating position.

Therefore, in the present embodiment, as described above,
An actuator in the Z-axis direction and a sensor 26 as a position (gap) detecting means in the Z-axis direction (flying direction) are provided in the substrate transfer movable section 19 in the transfer hand main body 17, and when the reticle substrate 2 starts floating from this sensor, A horizontal tilt, a flying height, a displacement component in the Z direction due to vibration and resonance are detected, and the actuator performs feedback control to cancel the error component and disturbance. Here, FIG. 9 shows a configuration of a reticle levitation control system of the present embodiment. The reticle levitation control deviation E (s) component is superimposed on the reticle levitation target value R (s) by the reticle levitation error and the disturbance signal D (s) detected by the sensor through the reticle levitation feedback control circuit. The control signal drives the actuator section of the substrate transfer movable section 19, and the actuating section drives the substrate transfer movable section 1.
By driving the reticle 9, the reticle substrate 2 is driven so as to cancel the tilt, the floating error amount, the residual vibration and the like generated on the reticle substrate 2, and as a result, the reticle floating control amount C (s) in which the error component is offset is output as the output displacement. can get. At this time,
As a transient characteristic, as shown in FIG.
The reticle levitation control deviation E (t) is added as shown in FIG. 8 (B) due to the detected disturbance during reticle levitation, and as a result, the above feedback control is performed.
As shown by a curve b in FIG. 8A, the reticle floating amount converges quickly (T1) to the target reticle floating amount. When the feedback is not performed, a floating transient characteristic as shown by a curve a in FIG. 8A is exhibited, and it takes time for natural decay to converge to the target flying height. In FIG. 9, G (s) is a transfer function obtained from the reticle levitation support system and the actuator, and H (H)
(S) is a reticle levitation feedback transfer function obtained from the feedback control system circuit, and L (s) is a reticle levitation disturbance transfer function.

In performing such control, the controllability is further improved by giving the leaf spring 18 a vibration damping effect. FIG. 10 shows the embodiment. Here, a cross section of the leaf spring 18 is shown in the upper view, where 18a
And 18c are thin plate springs made of phosphor bronze, stainless steel, etc., and a viscoelastic vibration damping material having a large internal loss between vibrations (isopropylene rubber, butadiene rubber, isobutylene isoprene rubber, ethylene propylene rubber,
Other rubber-based adhesives) are laminated and integrated.

By using the leaf spring 18 having such a configuration, the main resonance peak and the sub resonance generated in the leaf spring 18 itself during the floating of the reticle substrate 2 shown in FIGS. 10B to 10C are suppressed. By doing so, controllability is improved.
As shown in FIG. 11, the transfer function G obtained from the reticle levitation support system and the actuator shown in the configuration diagram of the feedback control system (FIG. 9) is improved as shown in FIG.
G (s) × product of (s) and reticle levitation feedback transfer function H (s) obtained from feedback control system circuit
It is shown in the figure which measured the loop transfer function which is H (s). Here, the horizontal axis indicates frequency F (Hz), and the vertical axis indicates gain (dB) and phase (degree), and indicates frequency response characteristics of the entire reticle levitation control system. In FIG. 11, the characteristic shown by the broken line indicates the characteristic when the damping material is not laminated on the leaf spring 18. As shown in the figure, the main resonance frequency f of the leaf spring
Since the resonance peak rises high at 1 and the resonance peaks at the higher-order sub-resonance frequencies f2 and f3 are high, if the control frequencies are near these frequencies in the control band frequency, the controlled object may oscillate. However, there is a possibility that the control becomes unstable and stable flying height control cannot be performed.
However, as shown in the above embodiment, by forming the damping material in the leaf spring 18 in a laminated structure, the damping material is applied to the leaf spring 18 having the characteristics shown by the broken line as shown by the solid line in FIG. Since the resonance peak is suppressed low at the main resonance frequency fl of the leaf spring and the resonance peak at the high-order sub-resonance frequencies f2 and f3, which is observed in the characteristics when the layers are not stacked, the control band frequency is It is possible to control the control target while increasing the control gain even if the frequency is increased, and the control will not be unstable, and stable flying height control can be performed. Accordingly, as to the levitation transient characteristic of the reticle substrate 2 at the start of levitation, as shown by the curve c in FIG. 12, the time until levitation stabilization is further reduced (T2).
Furthermore, quick control of the floating of the reticle substrate becomes possible.

As described above, by quickly obtaining the flying stability during alignment of the reticle substrate, the following alignment operation can be smoothly performed.

In the above floating state, the displacement of the reticle substrate 2 with respect to the reticle stage 1 is detected by the reticle alignment scopes 25a and 25b. The reticle substrate 2 is stably levitated by the air pads 24a to 24d, but has a very small amount (about 2 to several μm) smaller than the depth of focus (about 10 μm) of the reticle alignment scopes 25a and 25b, and detects a displacement. Is performed with sufficient accuracy. Next, the mark of the reticle substrate 2 is moved to the reticle alignment scope 25a by the XY plane fine movement mechanism 15 based on the detected value.
Positioning is performed so as to be at the measurement center of 5b. After positioning, the air pads 24a to 24d on which the reticle substrate 2 positioned on the reticle stage 1 is mounted by cutting off the air flow from the air pads 24a to 24d.
Then, reticle substrate 2 is vacuum-adsorbed, whereby reticle substrate 2 is positioned and fixed to reticle stage 1. The reticle substrate 2 is separated from the transfer hand 14 by turning off the vacuum suction by the substrate suction unit 20 of the transfer hand 14, and the transfer hand 14 is retracted to the position shown in FIGS. Complete. After the transfer is completed, the reticle alignment scopes 25a and 25b measure the amount of misalignment between the alignment mark formed on the reticle substrate 2 and the alignment mark provided on the reticle stage 1, and according to the measured value, the wafer is displaced. Scan exposure is performed by setting XYθ of the wafer 4 on the stage 5.

When detecting the positional deviation, first, the surface of reticle substrate 2 is observed with reticle alignment scopes 25a and 25b, and the alignment marks on reticle substrate 2 are aligned with reticle alignment scopes 25a and 25b.
Is within the measurement range, the air flow of the air pads 24a to 24d is switched to vacuum suction without performing the above positioning process, the vacuum suction by the substrate suction unit 20 is cut off, and the reticle substrate 2 is vacuum-chucked and transported. Complete. Even if the reticle alignment scope 25a, 25b of the reticle substrate 2 is not within the measurement range of the reticle alignment scope 25a, 25b, if the reticle alignment scope 25a, 25b is within the visual field of the reticle alignment scope 25a, 25b.
The displacement of the reticle substrate 2 can be detected without switching the magnification of 25b. The marks on reticle substrate 2 are aligned with reticle alignment scopes 25a, 25a.
If the reticle substrate 2 is out of the field of view, the magnification of the reticle alignment scopes 25a and 25b is switched to a low magnification to enlarge the field of view, and then the displacement of the reticle substrate 2 is detected.

As described above, after the alignment of the reticle substrate is completed, the reticle stage 1 and the Y stage are moved at a predetermined speed ratio in the Y direction (scanning direction).
The pattern on the reticle substrate 2 is exposed to a predetermined exposure area on the wafer 4 by scanning the pattern on the reticle substrate 2 with the slit-shaped exposure light and scanning the wafer 4 with the projected image. .

[0029]

[Embodiment of Micro Device Manufacturing] The manufacturing process of a general semiconductor device including pattern exposure will be described below. FIG.
Reference numeral 5 denotes a manufacturing flow of micro devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.).

In step 1 (circuit design), a circuit of a semiconductor device is designed. Step 2 is a process for making a mask on the basis of the circuit pattern design. On the other hand, in step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is referred to as a preprocess, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer manufactured in step 4, and includes an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. Process. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device manufactured in step 5 are performed. Through these steps, a semiconductor device is completed and shipped (step 7).

FIG. 16 shows a detailed flow of the wafer process (step 4). Step 11 (oxidation) oxidizes the wafer surface. Step 12 (CVD) forms an insulating film on the wafer surface. Step 13 (electrode formation) forms electrodes on the wafer by vapor deposition. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the above-described exposure apparatus to print a circuit pattern on the mask, which has been drawn on the reticle, onto the wafer. Step 17 (development) develops the exposed wafer. In step 18 (etching), parts other than the developed resist image are scraped off. Step 19 (resist stripping) removes the unnecessary resist after etching. By repeating the above steps, multiple circuit patterns are formed on the wafer.

By using the production method of this embodiment, a high-precision device, which was conventionally difficult to produce, can be produced at low cost.

[0033]

Modification of the Embodiment In the above embodiment, the floating control is performed by providing an actuator in the movable section of the substrate transfer. As shown in FIG. 13, the air pressure and the flow rate of each of the air pads 24a to 24d are controlled by the main piping. By using a servo valve 28 that controls the air pad 24 separately from the air pad 24,
The control system configuration shown in FIG. 9 (where the transfer function G (S) is the reticle levitation and air pressure and the flow control system transfer function G) (Change to (s)), simple flying height control can also be performed.

In the above embodiment, the reticle substrate 2
14 is detected by detecting the gap between the board transfer movable section 19 and the transfer hand main body.
As shown in FIG.
a, 30b are attached in a direction orthogonal to each other, and the displacement due to the bending of the leaf spring 18 is detected by the strain gauge 30a.
By detecting the displacement of the component in the torsion direction of the leaf spring 18 with the strain gauge 30b, the inclination and the flying height of the reticle substrate can be detected.

[0035]

As described above, according to the present invention,
When the reticle substrate is finely moved by the fine movement mechanism to position the reticle substrate, a gap displacement between the substrate suction portion of the elastically supported transfer hand and the transfer hand main body is detected, and the substrate is vertically lifted. By performing feedback control to cancel the deviation and vibration of the directional inclination and the flying height and the residual vibration, the floating state of the reticle substrate is stabilized quickly and horizontally at the time of fine movement positioning of the reticle substrate, The reticle alignment operation can be performed stably and quickly, and when the substrate transfer apparatus is used in an exposure apparatus, there is an effect that the total throughput and exposure accuracy of the exposure apparatus can be improved.

Further, by forming the elastic supporting portion of the transfer hand from an elastic support member in which a metal plate spring and a viscoelastic member are laminated in a single layer or a plurality of layers, especially when performing the above control, the transfer hand can be used. With a relatively simple configuration, it is possible to quickly attenuate the sub-resonance and the residual vibration generated in the supporting leaf spring elastic support portion and to stably perform the control.

Further, based on the gap displacement detection signal,
The effect of improving the alignment accuracy of the substrate (reticle) by the reticle alignment scope by controlling the pressure and flow rate of the air blown from the air pad to correct the tilt and vertical floating position of the substrate to an appropriate position. There is.

Further, by controlling the gap displacement detecting means and the actuator provided on the air pad portion at a higher speed using an electromagnetic actuator or the like, the tilt of the substrate and the floating position in the vertical direction can be adjusted properly. At high speed, and the residual vibration can be canceled at a high response frequency. This improves the alignment accuracy of the substrate (reticle) by the reticle alignment scope and improves the throughput of the above device. is there.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is an overall side view of the exposure apparatus of FIG.

FIG. 3 is a perspective view of a reticle transport device and a reticle stage according to one embodiment of the present invention.

FIG. 4 is a top view of the apparatus and the stage of FIG. 3;

FIG. 5 is an enlarged perspective view of the apparatus and the stage of FIG. 3;

FIG. 6 is an enlarged top view of the apparatus and the stage of FIG. 3;

FIG. 7 is a side view of the reticle transport device of FIG. 3;

8 is a control system characteristic diagram of the apparatus of FIG.

FIG. 9 is a control system board diagram of the apparatus of FIG. 3;

FIG. 10 is a side view of the reticle transport device.

FIG. 11 is a characteristic diagram of a control system.

FIG. 12 is a control system characteristic diagram.

FIG. 13 is a side view of a reticle transport device according to another embodiment of the present invention.

FIG. 14 is an enlarged top view of a reticle transport device and a reticle stage according to still another embodiment of the present invention.

FIG. 15 is a diagram showing a flow of manufacturing a micro device.

16 is a diagram showing a detailed flow of the wafer process in FIG.

FIG. 17 is a perspective view showing a reticle carrying state of the reticle transport device according to the prior application.

18 is a perspective view showing a reticle delivery state to a reticle stage of the apparatus of FIG.

FIG. 19 is an enlarged side view of a substrate suction unit in the apparatus of FIG.

[Explanation of symbols]

1: reticle stage, 2: reticle substrate, 3: linear motor, 4: wafer, 5: wafer stage, 5A: Z stage, 5B: linear motor, 5C: linear motor,
6: Stage surface plate, 7: Base frame, 8: Damper,
9: lens barrel base, 10: projection optical system, 11A: light emitting means,
11B: light receiving means, 12: laser interferometer, 13: Y-direction laser interferometer for reticle stage, 13B: Y-direction laser interferometer for wafer stage, 14: transfer hand, 15:
XY plane fine movement mechanism, 16: linear motor, 17: transfer hand main body, 18: leaf spring, 19: board transfer movable section, 2
0: substrate suction portion, 21A: yoke, 21B: yoke, 2
2A: magnet, 22B: magnet, 23A: coil, 23B: coil, 24a to 24d: air pad,
25a, 25b: reticle alignment scope, 2
6: sensor, 27a to 27b: pipe, 28: servo valve, 29: main pipe, 30a, 30b: strain gauge, 1
01: movable stage, 102: substrate, 103: linear motor, 104: fine movement mechanism, 105: movable stage, 11
4: transport hand, 115: fine movement mechanism, 116: linear motor, 117: transport hand body, 118: leaf spring, 12
0: substrate suction part, 124: air pad, 125a, 1
25b: Alignment scope.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/30 525E

Claims (11)

[Claims] 1. A substrate transfer device provided with a transfer hand for transferring a substrate and transferring it to a movable stage having an air pad, wherein the substrate is provided in a mechanism of the transfer hand and the substrate is drawn on the substrate surface. A fine movement mechanism for finely moving in a pattern drawing plane and around an axis perpendicular to the plane; a main body portion of the transfer hand, which constitutes the transfer hand, which can be moved in the horizontal and vertical directions; and a direction perpendicular to the main body portion. A substrate suction unit that is elastically supported by and holds the substrate horizontally; a unit that detects a floating amount of the substrate from the air pad; and a vertically moving each of the substrate suction units with respect to the transport hand body. An actuator to be driven, the transfer hand main body portion is vertically lowered at a substrate transfer position with the movable stage, and the substrate is brought into contact with an air pad on the movable stage. Or presses, blows air from the air pad to float the substrate by a small amount, and drives the actuator based on the output of the detecting means when positioning the substrate by finely moving the substrate by the fine movement mechanism. And correcting the inclination of the substrate,
Control means for performing at least one of flying height correction and vibration suppression. 2. The substrate transfer device according to claim 1, wherein the floating amount detecting means detects the floating amount based on a gap between the substrate suction part and the transfer hand main body or the movable stage. . 3. An elastic supporting portion for supporting the substrate suction portion with respect to the main body of the transfer hand is constituted by an elastic supporting member formed by laminating a metal plate spring and a viscoelastic member in a single layer or a plurality of layers, respectively. The substrate transfer device according to claim 1, wherein: 4. An exposure stage, and a transport hand that transports the substrate and transfers it to the exposure stage, and the mechanism of the transport hand has the substrate substrate in a pattern drawing plane drawn on the substrate surface. A fine movement mechanism is provided for finely moving around an axis perpendicular to the plane, and a plurality of main bodies capable of horizontally and vertically moving the transfer hand and elastically supported vertically in the main body to hold the substrate horizontally. A substrate transfer device configured by a substrate suction unit, and at a substrate transfer position between the transfer hand and the exposure stage, the transfer hand is lowered vertically to contact the substrate with an air pad on the exposure stage. Or, when pressing, the air is blown out from the air pad to float the substrate by a small amount, and the substrate is finely moved by the fine movement mechanism to position the substrate. Means for detecting a floating amount of the substrate from the air pad; means for driving the elastically supported substrate suction portion in a vertical direction; and correction of a tilt error of the substrate using the detection means and the driving means. An exposure apparatus comprising: control means for performing at least one of correction of a flying height error and suppression of vibration. 5. The exposure apparatus according to claim 4, wherein the flying height detecting means detects the flying height based on a gap between the substrate suction unit and the main body of the transfer hand or the exposure stage. 6. An elastic support member for supporting the substrate suction portion with respect to the transfer hand main body portion is constituted by an elastic support member formed by laminating a metal plate spring and a viscoelastic member in a single layer or a plurality of layers, respectively. The exposure apparatus according to claim 4, wherein 7. The apparatus according to claim 4, wherein the control means performs the error correction or the vibration suppression by performing feedback control of an air pressure and a flow rate blown from the air pad based on an output of the detection means. The exposure apparatus according to any one of the above items 4. 8. The substrate transfer apparatus further includes an actuator for driving each of the substrate suction units in a vertical direction with respect to the transfer hand main body, and the control unit controls the actuator based on an output of the detection unit. 8. The exposure apparatus according to claim 7, further comprising: performing feedback drive control. 9. An exposure apparatus according to claim 8, wherein said control means performs feedback drive control of said actuator and feedback control of said air pressure and flow rate separately for a control band frequency. 10. The control means mainly performs correction of the flying height and inclination of the substrate by feedback control of the air pressure and flow rate, and suppresses residual vibration during the flying by feedback control of the actuator. 9. The exposure apparatus according to claim 8, wherein the exposure is performed. 11. A device manufacturing method using the exposure apparatus according to claim 4. Description: