JP2908153B2 - Exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus used for manufacturing a semiconductor device, and more particularly to an exposure apparatus provided with a substrate supply apparatus for performing pre-alignment, supply, and recovery of a substrate such as a wafer to be exposed. .

[0002]

2. Description of the Related Art A conventional reduction projection type exposure apparatus (hereinafter, referred to as an exposure apparatus).
It is called "stepper". ) Indicates the base plate 1 as shown in FIG.
And an XY stage 102 driven by a known six-axis drive table mechanism supported by the XY stage 102
A top stage 103 mounted thereon, a reduction projection lens system 104 disposed above the top stage 103, an illumination system 105 disposed above the top stage 103, and a reticle 106 between the illumination system 105 and the reduction projection lens system 104. a stepper body S ₀ consisting of a reticle support device (not shown) for supporting, reduction projection lens system 104 is supported on and weighing table 101 via the lens system support 104a, the illumination system 105 includes a lens Illumination system support 105a integral with system support 104a
And is supported by the base 101. A plurality of air mounts 108 are provided between the base 101 and the floor 107,
Weighing table 101 is resiliently supported by the air mounts 108, thereby together with vibration of the floor 107 is prevented from being transmitted to the stepper body S ₀ directly, preventing resonance by self-oscillation of a stepper body S _0, and Absorbs external vibration transmitted from a wafer transfer conveyor or the like.

[0003] The illumination light emitted from the illumination system 105 is irradiated to the wafer W ₀ adsorbed on the top stage 103 through a reticle 106 and a reduction projection lens system 104,
To expose the resist on the surface of the wafer W _0.

A substrate supply device F ₀ for automatically supplying and recovering wafers is arranged near the side of the stepper body S ₀ , and the substrate supply device F ₀ is not shown in FIG. A supply cassette 109 for accumulating wafers loaded from a wafer transfer conveyor or the like, and a supply cassette 109
Pre-alignment device 110 for performing pre-alignment of wafers sequentially taken out by a robot (not shown)
And the wafer after pre-alignment
A loading hand 111 for carrying the _0, exposure, unloading hand 1 the wafer having been subjected to the baking recovered from the stepper body S ₀
12, has a recovery cassette 113 for stacking wafers recovered by unloading hand 112, all of which are supported on the support base 114 is integral with Taiban 101 of the stepper body S _0, for supplying feeding the pre-alignment apparatus 110 to wafer in the cassette 109 is sequentially taken out by the aforementioned robot, exposure and carried into the stepper body S ₀ by wafer loading hand 111 having been subjected to the pre-alignment, performed baking, exposure, baking finish a series of operations by unloading the wafer hand 112 is recovered from the stepper body S ₀ is housed in collecting cassette 113 is continuously performed.

[0005] The pre-alignment apparatus 110 includes a pre-alignment stage 115 for adsorbing a wafer supplied from the supply cassette 109 and a pre-alignment stage 115, which are two axes orthogonal to each other (hereinafter, "X axis," respectively).
It is called “Y axis”. ), And a pre-alignment stage driving device 116 that rotates around an axis perpendicular to the two axes (hereinafter, referred to as “Z axis”).
And a position sensor 117 for detecting the position of the wafer adsorbed on the pre-alignment stage 115.
The position sensor 117 is shown in FIGS. 7A and 7B.
, One X position sensor 117a,
X-axis direction are arranged at predetermined intervals a pair of Y position sensor 117b, have 117c, first, while rotating the pre-alignment stage 115, the output of the X position sensor 117a of the wafer W ₁ orientation flat (the outer peripheral edge provided the notch) to detect the rotational position of the C _1, the orientation flat C ₁ is both Y position sensor 117b, 117
pre-alignment stage 115 at a position parallel to c
Is stopped (shown by (b) in FIG. 7), the pre-alignment stage 115 is moved in the Y-axis direction, and the alignment in the Y-axis direction is performed based on the outputs of both the Y position sensors 117b and 117c. Then, the pre-alignment stage 115 is moved in the X-axis direction, and the X-position sensor 117a performs position adjustment in the X-axis direction.

The wafer that has been pre-aligned in this manner is loaded into the stepper body S ₀ by the loading hand 111.
After the final alignment with higher accuracy by the XY stage 102, exposure is performed as described above. The final alignment is to drive the XY stage 102 by optically detecting an alignment mark preliminarily printed on the wafer. The final alignment requires a high degree of accuracy that causes an error of 1/100 μm. For improvement, it is performed at such a high speed that a delay of 1/100 second is problematic. For this reason, the accuracy of pre-alignment performed before final alignment is required to be about 20 μm to 60 μm, and in addition, the pre-alignment stage driving device 116 needs to be driven at a high speed. However, as described above, the operations of the substrate supply device F ₀ and the stepper body S ₀ are continuously repeated for each wafer, and the wafer is taken out from the supply cassette 109 in the substrate supply device F ₀ . A step of performing pre-alignment by mounting on the pre-alignment stage 115;
The steps of storing the wafer collected from the stepper body S ₀ by the unloading hand 112 in the collection cassette include the steps of performing the final alignment of the wafer on the top stage 103 and the subsequent exposure and printing in the stepper body S ₀ . Since almost at the same time, vibrations of the pre-alignment stage driving device 116 and a driving device such as a robot for transferring a wafer to the collection cassette 113 are transmitted to the base 101 via the support base 114, and the stepper body S ₀
There is a possibility that the accuracy of final alignment and printing in the above may be reduced, and various measures have been taken to prevent such vibrations.

[0007]

However, according to the above-mentioned prior art, a robot or the like for transferring a wafer to a collection cassette has a long operation stroke and requires a complicated operation. It is very difficult to control. Also, since the pre-alignment stage driving device is also complicated and heavy, it is difficult to prevent its vibration. These vibrations increase as the driving speed of the robot or the pre-alignment stage driving device increases, and are transmitted to the stepper body through a support table that is integrated with the stepper body base plate, and the accuracy of the final alignment, exposure, and printing is performed. Is significantly reduced. For this reason,
The robot and the pre-alignment stage driving device cannot be driven at a sufficiently high speed, which hinders an improvement in the throughput of the entire exposure apparatus, and cannot improve the productivity.

The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and can prevent the vibration of the substrate supply device from being transmitted to the base plate of the stepper body as a whole or partially. An object of the present invention is to provide an exposure apparatus.

[0009]

In order to achieve the above object, an exposure apparatus according to the present invention comprises a platform elastically supported by elastic support means, and an XY movably supported on the platform. An exposure apparatus comprising: a stage; a driving unit for moving the XY stage; and a substrate supply device for supplying a substrate to the XY stage, wherein the substrate supply device is supported separately from the base. On the platform
The XY stay moved from the exposure position to the substrate delivery position
Based on a change in the relative position of the platform and the substrate supply device when the substrate supply device supplies the substrate to the
The XY stage moves from the board transfer position on the base
The XY stage is configured to correct an amount of movement of the XY stage when returning to the exposure position .

[0010] Further, a base plate elastically supported by the elastic support means, and an XY movably supported on the base plate
A stage, driving means for moving the XY stage,
An exposure apparatus having a substrate supply device for supplying a substrate to the XY stage, wherein a pre-alignment of the substrate supply device is performed.
The position sensor of the mounting device is provided integrally with the base
Was supported by a supporting table, the pre-alignment stage driver for moving the pre-alignment stage of the pre-alignment apparatus of the board supply device may be separately supported and the base plate.

[0011]

According to the above-described apparatus, since the substrate supply device is supported separately from the base plate, it is possible to prevent the vibration of the robot of the substrate supply device and the pre-alignment stage driving device from being transmitted to the base plate.

Since the base plate is elastically supported, the base plate undergoes a lateral sway, and when a substrate is transferred between the XY stage and the substrate supply device, the relative position of the two changes and the transfer is performed. A displacement occurs between the moved substrate and the XY stage. In order to prevent the transfer deviation caused by such a positional deviation, when the substrate is transferred, a change in the relative position between the substrate supply device and the base is detected by a detecting means, and the XY stage is moved on the substrate transfer position on the base. even in the very Rutoki the exposure position from and corrected based on the movement amount to the output of said detecting means.

Further, if the pre-alignment stage driving device for moving the pre-alignment stage of the pre-alignment device of the substrate supply device is supported separately from the base, the vibration of the pre-alignment stage driving device is prevented from being transmitted to the base. be able to.

[0014]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic elevational view showing a first embodiment. The exposure apparatus of the present embodiment is supported by a base 1 and is moved by a known six-axis drive table mechanism which is a driving means. Stage 2, top stage 3 mounted on XY stage 2, reduction projection lens system 4 disposed above, illumination system 5 disposed above, illumination system 5 and reduction projection lens system has a stepper body S ₁ consisting of a reticle support device (not shown) for supporting the reticle 6 disposed between the 4, reduction projection lens system 4 is a lens system support 4
The illumination system 5 is supported by the base 1 through the lens system support 4a, and the lens system support 4a and the illumination system support 5 integrated therewith.
It is supported on the base via a. A plurality of air mounts 8 as elastic support means are provided between the base 1 and the floor 7 or a fixed plate (not shown) on the floor 7, and the base 1 is elastically supported by each air mount 8. vibration of the floor 7 is prevented from being directly transmitted to the stepper body S _1, to prevent resonance due to the self-oscillation of a stepper body S _1, and to absorb external vibrations transmitted from the substrate carrying conveyors and the like by.

Illumination light emitted from the illumination system 5 passes through the reticle 6 and the reduction projection lens system 4 and is transmitted to the top stage 3.
A wafer (not shown), which is a substrate adsorbed on the wafer, is irradiated to expose a resist on the surface of the wafer.

[0017] On the side near the stepper body S _1, automatically supply the wafer, it is provided a substrate feeding device F ₁ for recovery, the substrate feeding device F _1, as shown in FIG. 2, not shown A supply cassette 9 for accumulating wafers carried in from a conveyor or the like, a pre-alignment device 10 for performing pre-alignment of wafers sequentially taken out from the supply cassette 9, and a stepper main body S _1. a loading hand 11 is carried into the exposure, the robot 1 to perform a wafer having been subjected to the baking operation and recovered from the stepper body S _1, alternating the operation of loading and unloading successive wafer from the supply cassette 9 to the pre-alignment device
2 and a collection cassette 13 for collecting the wafers collected by the robot 12, all of which are on the support 1
Is supported by 4, support 14 is Taiban 1 and separate stepper body S _1, a gap T ₁ between the weighing table 1, the legs directly bed 7 or the floor of the support 14 7 is fixed to a fixed platen.

Further, the supporter 14 is provided with a stepper body S _1.
Rolling occurs and the gap sensor width of the gap T ₁ is a detecting means for detecting this when changes are provided by self-oscillation or the like. The gap sensor has a gap T _1.
Gap sensor 1 for measuring the change Δx in the width in the X-axis direction
4a and a pair of Y gap sensors 14b and 14c for measuring a change in width Δy in the Y-axis direction. The Y gap sensors 14b and 14c are arranged at a predetermined interval in the X-axis direction, and the gap T _{1 is provided.} Of the width in the Y-axis direction is measured, and the difference between the outputs of the Y gap sensors 14b and 14c is used to determine the Z of the support 14 relative to the base ₁ of the stepper body S1.
The change Δθ in the rotation angle about the axis can be calculated.

The pre-alignment apparatus 10 has a pre-alignment stage 15 on which a wafer taken out of the supply cassette 9 is mounted, and a pre-alignment stage 15 for moving the wafer in the X-axis, Y-axis, and Z-axis directions. It has a pre-alignment stage driving device 16 for moving around and a position sensor 17 for detecting the orientation flat of the wafer.

The supply cassette 9 is controlled by the robot 12.
Taken from the wafer placed on the pre-alignment stage 15, after being aligned in place by pre-alignment apparatus 10, the loading hand 11 and transferred to the XY stage 2 of a stepper body S _1.
At this time, the XY stage 2 moves the substrate transfer position on the base 1 by a predetermined distance from the exposure position toward the pre-alignment apparatus 10 by the above-described six-axis drive table mechanism.
At the wafer transfer position. The wafer transferred from the pre-alignment apparatus 10 by the loading hand 11 is
When the Y stage 2 receives, the X gap sensor 14a
And both Y gap sensors 14b, 14c change Δx in size of the gap T ₁ of the Taiban 1 of support 14 and the stepper body S ₁ of the substrate feeding device F _1, [Delta] y, is Δθ is determined by the measured value, the stepper When the XY stage 2 receiving the wafer is returned from the wafer transfer position on the base 1 to the exposure position, the XY stage 2 is stored in the control device which is the control means of the 6-axis drive table mechanism of the XY stage 2 of the main body S _1. Correct the amount of movement. In other words, weighing table 1, as described above, since it is supported on resiliently the floor 7 via the air mount 8, when performing the transfer of the wafer, the rolling by the self vibration of the stepper body S ₁ occurs, the tend to size of the gap T ₁ is changed, in this way the dimension of the gap T ₁ is changed, the relative position of the wafer on the XY stage and the pre-alignment stage 15 in the wafer transfer position is changed , The wafer cannot be transferred to a predetermined position on the XY stage 2, and the same positional displacement as the change in the width of the gap T ₁ occurs. Therefore, such a positional shift as a change in the relative position is detected by the X gap sensor 14a and the Y gap sensors 14b and 14c, and when the XY stage 2 returns from the wafer transfer position to the exposure position by the six-axis drive table mechanism. By correcting the amount of movement, it is possible to prevent the wafer at the exposure position from being misaligned.

When the XY stage 2 returns to the exposure position, final alignment of the wafer is performed by an alignment optical system (not shown).
Baking is performed. Exposure, the wafer having been subjected to the baking is housed taken from the stepper body S ₁ by the robot 12 to the collection cassette 13. While the wafer is accommodated in the collecting cassette 13 by the robot 12, the exposure following the final alignment of the stepper body S ₁ In the next wafer, baking is performed at the same time, pre-alignment apparatus 1
At 0, the wafer is pre-aligned for exposure and printing.

According to the present embodiment, the support table 14 of the substrate supply apparatus F ₁ is directly supported on the floor 7 by its legs and is separate from the base ₁ of the stepper body S _{1. 1} of the vibration due to the drive of the pre-alignment apparatus 10 or robot 12, without being transferred to the stepper body S _1, therefore, pre-alignment apparatus 10 or robot 12
The be driven at a high speed, the wafer final alignment and exposure in the stepper body S _1, the accuracy of the baking will not deteriorate.

The support table 14 of the substrate supply device F ₁
And wipe the Z position sensor for detecting the positional deviation in the Z-axis direction of the Taiban 1 stepper body S _1, the stepper body S ₁
If the self-vibration is significant, the delivery of the wafer by the loading hand 11 may be temporarily stopped.

As the X gap sensor 14a and the Y gap sensors 14b and 14c, a non-contact position sensor of a magneto-optical or capacitance type, a dial gauge having a small contact pressure, or the like is used.

FIG. 3 shows a partially modified example of the present embodiment. When the pre-aligned wafer is transferred to the XY stage of the stepper body by the loading hand, the XY stage at the wafer transfer position and the pre-alignment are transferred to the XY stage. A change in the relative position of the alignment stage is detected by a position sensor, and instead of correcting the amount of movement when the XY stage returns to the exposure position, the stepper body is temporarily moved when the wafer is transferred from the pre-alignment apparatus to the XY stage. When the XY stage is at the wafer transfer position, the relative position between the base plate of the stepper body and the substrate supply device does not change by providing the lock device 20 which is a temporary fixing means for fixing the base plate at a predetermined position. It is composed.

The lock device 20 includes a plurality of positioning guides 21 each having a tapered guide hole 21a adjacent to the outer peripheral edge of the base 1, and a plurality of taper pins 22 provided at predetermined positions of the base 1. Then, the base 1 is raised and each tapered pin 22 is guided by the guide hole 21 a of the positioning guide 21.
, And each positioning guide 21 includes an air cylinder 23 that drives the push-up pin 23.
Along with a, the stepper body S1 is fixed to the floor 7 at a position near each air mount 8 of the base ₁ of the stepper body S1.

When the XY stage 2 is moved to the wafer transfer position by the six-axis drive table mechanism, the air cylinders 23a are driven to raise the push-up pins 23, respectively, so that the base 1 is within the allowable range of the air mount 8. To rise slightly. As a result, each taper pin 22 engages with each guide hole 21a of the positioning guide 21, and the base 1 is temporarily fixed. The transfer of the wafer is performed with the base 1 fixed at a predetermined position as described above, and therefore, there is no possibility that the above-described positional shift due to the lateral swing of the stepper body occurs.

FIG. 4 is a schematic elevational view showing the second embodiment. In the present embodiment, as in the first embodiment, the base plate 31 supported on the floor 37 via the air mount 38 is shown. XY stage 32 supported by this, top stage 33,
A reduction projection lens system 34, a lens system support 34a, an illumination system 35, illumination system support 35a, a stepper body S ₂ consisting of a reticle support device (not shown) for supporting the reticle 36, in FIG. 2 A supply cassette (not shown) similar to the supply cassette 9, a pre-alignment device 40,
Has a loading hand 41, the board supply device F ₂ made of the same robot and collecting cassette with the robot 12 and the recovery cassette 13 in FIG. 2 (both not shown).
The pre-alignment device 40 also includes a pre-alignment stage 45, a pre-alignment stage driving device 46, and a position sensor 47, as in the first embodiment. The difference from the first embodiment is that the support base 1 of the first embodiment is different from the first embodiment.
4 supports a supply cassette, a collection cassette, a robot and carry-in hand 41, and a position sensor 47 of the pre-alignment device 40, and the stepper body S ₂ as in the conventional example. The pre-alignment stage 45 of the pre-alignment device 40 and the pre-alignment stage driving device 46 for driving the pre-alignment stage 45 are separate from the base 31 and are directly fixed to the floor 37. Is supported by the fixed table 48.

In this embodiment, the vibration of the pre-alignment stage 45 of the pre-alignment device 40 and the vibration of the pre-alignment stage driving device 46 are not transmitted to the base 31 of the stepper body S ₂ via the support base 44. Even if the pre-alignment device 40 is driven at a high speed,
This stepper body S ₂ final alignment and exposure in the accuracy of baking not deteriorate.

Since the base 31 of the stepper body S ₂ is elastically supported on the floor 37 via the air mount 38, the self-vibration of the stepper body S ₂ causes the base 31.
Of the pre-alignment device 40 supported by a support 44 that is integral with the
7 and the relative position of the pre-alignment stage 45 supported by the fixed base 48 changes. Therefore, the acceleration of the base plate 31 is monitored, and a monitor device that is a detecting means for detecting the deviation of the horizontal displacement, and the output of the monitor device is fed forward to the pre-alignment stage driving device 46 to move the pre-alignment stage. Either a control device as a control means for correcting the amount is provided, or a position sensor as a detection means for detecting a change in the position of the base plate 31 that is a lateral shake is provided, and the output of the position sensor is differentiated twice. Alternatively, it is desirable to provide a control device which is a control means for directly feeding back.
Thus, it is possible to prevent the pre-alignment process from being complicated due to the change in the relative position, and to improve the throughput.

[0031]

Since the present invention is configured as described above, it has the following effects.

The vibration of the substrate supply device can be wholly or partially prevented from being transmitted to the base plate of the exposure apparatus. As a result, the accuracy of final alignment, exposure, and printing of the exposure apparatus due to the vibration is reduced, and the robot and the pre-alignment apparatus of the substrate supply apparatus can be driven at a high speed. As a result, the throughput of the exposure apparatus can be improved and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic elevation view showing a first embodiment.

FIG. 2 is a schematic plan view of the device of FIG.

FIG. 3 is a partial schematic elevation view showing a part of a partially modified example of the first embodiment.

FIG. 4 is a schematic elevation view showing a second embodiment.

FIG. 5 is a schematic elevation view showing a conventional example.

FIG. 6 is a schematic plan view of the device of FIG.

FIGS. 7A and 7B illustrate a position sensor of the pre-alignment apparatus. FIG. 7A is a diagram showing a state before detecting an orientation flat of a wafer, and FIG. 7B is a diagram showing a state of detecting the orientation flat.

[Explanation of symbols]

S ₁ , S ₂ Stepper body F ₁ , F ₂ Substrate feeder 1,31 Board 2,32 XY stage 3,33 Top stage 4,34 Reduction projection lens system 5,35 Illumination system 6,36 Reticle 8,38 Air Mount 9 Supply cassette 10, 40 Pre-alignment device 11, 41 Loading hand 12 Robot 13 Collection cassette 14, 44 Support table 14a X gap sensor 14b, 14c Y gap sensor 15, 45 Pre-alignment stage 16, 46 Pre-alignment stage drive Apparatus 17, 47 Position sensor 20 Locking device 21 Positioning guide 22 Taper pin 23 Push-up pin 23a Air cylinder 48 Fixed base

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/027

Claims (4)

(57) [Claims] A pedestal resiliently supported by elastic support means, an XY stage movably supported on the pedestal, drive means for moving the XY stage;
An exposure apparatus having a substrate supply device that supplies a substrate to a Y stage, wherein the substrate supply device is supported separately from the base, and the driving unit is configured to detect whether the exposure position is on the base.
To the XY stage moved to the substrate transfer position
The XY step is performed based on a change in the relative position between the platform and the substrate supply device when the plate supply device supplies the substrate.
The exposure position from the substrate delivery position on the platform
Correct the amount of movement of the XY stage when returning to the position
An exposure apparatus characterized in that it is configured as follows . 2. A base plate resiliently supported by elastic support means, an XY stage movably supported on the base plate, a driving means for moving the XY stage,
An exposure apparatus having a substrate supply device for supplying a substrate to a Y stage, wherein the substrate supply device is on a floor separately from the base plate.
To the XY stage.
When the plate supply device supplies the substrate, the elastic support
The platform, which is elastically supported by steps, is
Exposure apparatus characterized by having a temporary fixing means for temporarily fixing to pair. 3. A board resiliently supported by elastic support means, an XY stage movably supported on the board, drive means for moving the XY stage, and
An exposure apparatus having a substrate supply device for supplying a substrate to a Y stage, wherein a pre-alignment device of the substrate supply device is provided.
Position sensor is provided integrally with the base plate
Supported by a supporting table, exposing the pre-alignment stage driving device for moving the pre-alignment stage of the pre-alignment apparatus of a board supply apparatus is characterized in that it is separate from the support and the base plate unit. 4. A pre-alignment stage driving device,
4. The exposure apparatus according to claim 3, further comprising control means for correcting the amount of movement of the pre-alignment stage based on the output of the detection means for detecting the horizontal displacement of the platform.