JP2903958B2 - Positioning device and method of manufacturing semiconductor device using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for manufacturing a semiconductor device and a method for manufacturing a semiconductor device using the same, and more particularly to a method for manufacturing a semiconductor device using the same. For transferring the XY stage or the stage on the XY stage, on which the wafer is mounted, in a two-dimensional plane or three-dimensionally to a predetermined position when the transfer is performed in close contact with the projection optical system or directly. Things.

[0002]

2. Description of the Related Art Conventionally, in a projection exposure apparatus such as a stepper for projecting a pattern drawn on a reticle onto a wafer,
A function is provided for performing alignment between the reticle and the wafer, and exposure is performed after the alignment is performed.

In such alignment, generally, the amount of displacement between an original plate such as a reticle on which a pattern to be projected is drawn and an object to be exposed such as a wafer is measured, and the object to be exposed is determined based on the result. Is carried out by moving the XY stage on which is mounted by the length measurement control by the laser interferometer, or by moving the original plate and the object to be exposed.

The positioning of the XY stage involves X, Y
With respect to the axis, positioning is performed by a laser interferometer that measures the length using a laser beam.

[0005] Since the laser interferometer measures the wavelength of light as a reference, a length measurement error occurs in air due to a change in the refractive index of air, and the length measurement becomes unstable.

Therefore, conventionally, the measurement error is corrected by the following method.

(1-1) A fixed length composed of super invar, zero joule, or the like is differentially measured by a laser interferometer, and a change in the output of the laser interferometer is regarded as a change in the refractive index of air, and the position of the stage is detected. The value of the laser interferometer is corrected. This fixed length is often mounted near the optical path of the laser interferometer for detecting the position of the stage or on the stage.

(1-2) The refractive index of air is determined by temperature, pressure,
It changes depending on humidity and the like. Above all, it is sensitive to temperature and atmospheric pressure, and these changes cause the laser interferometer to have a length measurement error. Therefore, conventionally, the temperature and the atmospheric pressure are monitored at predetermined representative points on the apparatus, and the length measurement error of the laser interferometer is corrected.

In the manufacture of a semiconductor integrated circuit, when positioning a wafer, the wafer is moved in the Z direction on an XY stage that moves in the XY directions, and rotated about the X axis (hereinafter referred to as "ω _X
Direction), rotation about the Y axis (hereinafter “ω _Y direction”)
), And a separation type positioning device equipped with a stage that rotates around the Z axis (hereinafter referred to as the “ω _Z direction”).

In general, when driving the XY stage, for example, in Japanese Unexamined Patent Publication No. 3-142136, both the X stage and the Y stage are driven by two linear motors.

[0011]

Among the methods for measuring and positioning using a conventional laser interferometer, the aforementioned (1-1)
The method has the following problems.

(2-1) In order to increase the correction resolution, the fixed length must be very long. However, providing a long fixed length on the stage is very difficult in terms of manufacturing and cost.

(2-2) If a large distribution occurs in temperature and pressure, a positioning error occurs.

The method (1-2) has the following problems.

(2-3) Since the monitor is a monitor for only one representative point in the optical path, it is not possible to correct changes in temperature and pressure over the entire optical path of the laser interferometer, and the correction error is relatively large.

(2-4) The monitor monitors and compensates for relatively slow changes in temperature and pressure.

However, in a projection exposure apparatus for manufacturing a semiconductor element, the ambient temperature may fluctuate, for example, in a cycle of about one minute, and the atmospheric pressure may fluctuate by about 0.5 mbar in one minute. Therefore, in such a case, it is difficult to make a good correction.

A first object of the present invention is to provide a projection exposure apparatus for manufacturing a semiconductor device, etc., even if the temperature distribution in the optical path from the XY stage on which the wafer is mounted to the laser interferometer is not constant, and the ambient pressure It is an object of the present invention to provide a positioning device capable of controlling the movement of the XY stage, that is, positioning with high accuracy, without being adversely affected by these environmental changes even if it changes variously, and a method of manufacturing a semiconductor device using the same. .

In the conventional separation type positioning device, XY
A structure for supporting a guide and an actuator in each moving direction of the stage is provided.

Therefore, there are the following problems.

(2-5) Increase in weight of stage (2-6) Positioning time is prolonged.

In addition, in a positioning device using two linear motors, the X stage serves both for driving in the X direction and in the ω _Z direction. However, since the entire X stage is rotated in the ω _Z direction, There were problems such as (2-5) and (2-6).

[0023] When more straight driving the stage, it is difficult to drive at the center of gravity of the stage, particularly omega _Z direction of the rotation (oscillation) error occurs, the positioning accuracy there is a problem that comes to decrease.

A second object of the present invention is to appropriately configure each element for driving and controlling a stage on which a wafer as an object is mounted, thereby simplifying the entire apparatus and setting a predetermined wafer. It is an object of the present invention to provide a positioning device capable of positioning a position with high accuracy and a method for manufacturing a semiconductor device using the positioning device.

[0025]

Means for Solving the Problems (3-1) The positioning apparatus according to the present invention comprises: (3-1-1) an object to be aligned is placed on a part of an XY stage that moves in an XY plane. A mirror is provided, a laser beam from the first laser interferometer is made incident on the mirror, and the X-ray is transmitted using the laser beam passing through the mirror.
In a positioning apparatus for controlling the positioning of a Y stage by a control means, a first temperature measuring means for measuring a temperature distribution in the optical path is provided in an optical path from the first laser interferometer to the mirror, and the XY stage is provided. A second laser interferometer is provided at a location where the air conditioning is substantially the same as that of the second laser interferometer, and a second temperature measuring means for measuring a temperature distribution in the optical path is provided in an optical path of the second laser interferometer. Means for calculating, using signals from the second laser interferometer and the second temperature measuring means, a change in oscillation wavelength from the second laser interferometer excluding the influence of temperature, and (1) Using the signal from the temperature measuring means to calculate the effect of the change in the oscillation wavelength included in the signal obtained by the first laser interferometer, and calculating the XY based on the calculation result.
It is characterized in that the position of the stage is corrected to reduce the influence of the change in the oscillation wavelength from the first laser interferometer.

In particular, the second laser interferometer and the first and second laser interferometers
The second temperature measuring means is provided in at least one of the XY directions.

(3-1-2) An object to be aligned is placed, and a mirror is provided on a part of an XY stage that moves in the XY plane, and laser light from the first laser interferometer is incident on the mirror. And using the laser light passing through the mirror, the X
In a positioning device for controlling the positioning of a Y stage by a control means, a first temperature measuring means for measuring a temperature distribution in the optical path in an optical path from the first laser interferometer to the mirror and a pressure distribution are measured. The first air pressure measuring means for the second air conditioner is placed in the same air-conditioned place as the XY stage.
A laser interferometer is provided in the optical path of the second laser interferometer with a second temperature measuring means for measuring a temperature distribution in the optical path and a second air pressure measuring means for measuring an air pressure distribution, respectively. The control means uses the signals from the second laser interferometer, the first and second temperature measuring means, and the signals from the first and second atmospheric pressure measuring means to generate an oscillation included in a signal obtained by the first laser interferometer. It is characterized in that the influence of the change in the wavelength is calculated, and the position of the XY stage is corrected based on the calculation result, so that the influence of the change in the oscillation wavelength from the first laser interferometer is reduced.

In particular, the second laser interferometer and the first and second laser interferometers
The second temperature measuring means and the first and second atmospheric pressure measuring means are provided in at least one of the XY directions.

(3-1-3) A base having a flat portion substantially parallel to the XY plane, supported on the flat portion of the base by a hydrostatic gas bearing, and along the flat portion in the Y direction by first guide means. The first stage, the first driving means for driving the first stage, and the second guide means provided on the first stage. A second stage supported by a hydrostatic gas bearing on a flat portion of the base movable in a direction, and rotated in the Z direction and the X, Y, and Z axes with respect to the second stage by third guide means. A possible third stage, a second driving means provided on the first stage for moving the second stage in the X-axis direction and rotating about the Z-axis with respect to the first stage, and on the second stage The second stage provided On the other hand, an object provided on the third stage is positioned by using third driving means for moving the third stage in the Z-axis direction and rotating about the X-axis and the Y-axis. And

In particular, (3-1-3-1) position detecting means arranged substantially parallel to the XY plane and arranged so that Abbe error with respect to the object becomes substantially zero, and the position provided on the third stage. It has a detection target for the detection means, and an angle detection means for detecting an angle of the detection target.

(3-1-3-2) The position detecting means and the angle detecting means comprise a laser interferometer, and the detection target comprises a reflection mirror.

(3-1-3-3) The angle detecting means detects a position other than the position detected by the position detecting means, and calculates a difference between the position and the position detected by the position detecting means. It is characterized in that the angle is calculated.

(3-1-3-4) The first guide means is constituted by a guide member provided on the base in the Y direction and a hydrostatic gas bearing provided on the first stage. I have.

(3-1-3-5) The guide member is made of a magnetic material, and is structured such that an attractive force is exerted by a magnet provided on the first stage.

(3-1-3-6) The first driving means drives two positions offset in the X direction in the Y direction with the center of gravity of the first stage sandwiched therebetween using two actuators each of which can be controlled. It is characterized by having.

(3-1-3-7) The second guide means is constituted by a guide member provided on the first stage in the X direction and a hydrostatic gas bearing provided on the second stage. Features.

(3-1-3-8) The third guide means is fixed to the third stage, and has a cylindrical first guide member for guiding rotation around the Z direction and the Z axis. An opposing second guide member, a hydrostatic gas bearing provided on one of the first guide member or the second guide member and supporting the other;
The second guide member and the second stage are at least X
And an elastic member rigidly connected in the direction or the Y direction.

(3-1-3-9) The elastic member is a leaf spring that is substantially parallel to the XY plane and is flexible in the Z direction, around the X axis, and around the Y axis.

(3-1-3-10) A Z-direction damper is inserted between the second guide member and the second stage.

(3-1-3-11) The third guide means has a plurality of rod members which are rigid in the axial direction and flexible in the other direction, or a plurality of hinge members provided with a plurality of constricted portions in the rod members. Each virtual straight line passing through the axis of the hinge member is radially arranged around the XY center of the third stage in a plane substantially parallel to the XY plane, and one end of the hinge member is connected to the second stage. The other end is fixed to the third stage, and the third stage becomes rigid in the X direction and the Y direction with respect to the second stage.
It is characterized by being connected so as to be flexible around the axis.

(3-1-3-12) The second driving means uses the two actuators, each having a center of gravity sandwiched by the third stage and capable of controlling two locations offset in the Y direction, in the X direction and in the Z direction. It is characterized by being driven to rotate around an axis.

(3-1-3-13) The actuator is a linear motor.

(3-1-3-14) The third drive means is attached to a piezo element and both ends of the piezo element in the expansion and contraction direction,
An actuator composed of a hinge member whose rotation about an axis perpendicular to the direction of expansion and contraction is flexible is provided between the second stage and the third stage so that the direction of expansion and contraction of the actuator is substantially in the Z direction. And the third stage and the second stage are driven around the Z-direction, around the X-axis, and around the Y-axis.

(3-1-3-15) The actuator is a linear motor.

(3-1-3-16) Providing a position sensor for detecting three positions in the Z direction of the third stage, or detecting the Z direction, around the X axis and around the Y axis of the third stage By providing one position sensor and two angle sensors, the third stage can be rotated in the Z-axis direction, around the X-axis,
It is characterized in that positioning around the axis is performed.

(3-1-3-17) The third stage is characterized by being supported by a support means which is rigid in the Z direction and flexible in the other direction.

(3-1-3-18) The support means utilizes a repulsive force of a coil spring or a magnet.

(3-2) In the method of manufacturing a semiconductor device according to the present invention, (3-2-1) the relative position between the reticle and the wafer is detected, and then the pattern on the reticle surface is transferred to the wafer surface. Then, in the method of manufacturing a semiconductor device for manufacturing the semiconductor device through the developing process of the wafer, the wafer is placed, a mirror is provided on a part of an XY stage that moves in an XY plane, and the mirror is provided with a mirror. When the laser beam from the first laser interferometer is made incident and the control means controls the positioning of the XY stage by using the laser beam passing through the mirror, the laser beam travels in the optical path from the first laser interferometer to the mirror. A first temperature measuring means for measuring a temperature distribution in the optical path;
A second laser interferometer is provided at a location where the air conditioning is substantially the same as the stage, and a second temperature measuring means for measuring a temperature distribution in the optical path is provided in an optical path of the second laser interferometer. Using the signals from the second laser interferometer and the second temperature measuring means to calculate a change in the oscillation wavelength from the second laser interferometer excluding the influence of temperature, And using the signal from the first temperature measuring means to calculate the effect of the change in the oscillation wavelength included in the signal obtained by the first laser interferometer, and correct the position of the XY stage based on the calculation result. Thus, the present invention is characterized in that the influence of the change in the oscillation wavelength from the first laser interferometer is reduced.

(3-2-2) After the relative position between the reticle and the wafer is detected, the pattern on the reticle surface is transferred to the wafer surface, and the wafer is subjected to a developing process to manufacture semiconductor elements. In this method, a mirror is provided on a part of an XY stage that moves in an XY plane, and a laser beam from a first laser interferometer is incident on the mirror. A first temperature measurement for measuring a temperature distribution in the optical path in an optical path from the first laser interferometer to the mirror when the positioning of the XY stage is controlled by the control means using the transmitted laser light. Means and a first atmospheric pressure measuring means for measuring an atmospheric pressure distribution, a second laser interferometer in a place where air conditioning is substantially the same as that of the XY stage, and an optical path in the optical path of the second laser interferometer. The temperature distribution of A second temperature measuring means and a second atmospheric pressure measuring means for measuring an atmospheric pressure distribution are respectively provided, and the control means comprises the second laser interferometer, the first and second temperature measuring means, and the first and second temperature measuring means. Using the signal from the barometric pressure measuring means to calculate the effect of the change in the oscillation wavelength included in the signal obtained by the first laser interferometer, correcting the position of the XY stage based on the calculation result, It is characterized in that the influence of the change of the oscillation wavelength from the first laser interferometer is reduced.

[0050]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention, and FIG.
FIG. 2 is a YZ sectional view of a part of FIG.

This embodiment shows a case where the present invention is applied to an XY stage for manufacturing a semiconductor device.

In the drawing, reference numeral 1 denotes a wafer as an object to be aligned with a reticle (not shown). Reference numeral 2 denotes a wafer chuck which holds the wafer 1. Reference numeral 3 denotes an X stage, which holds the wafer chuck 2 and is driven by a DC servo motor 4 in the X direction. Reference numeral 5 denotes a Y stage, on which the X stage 3 is mounted and driven by a DC servo motor 6 in the Y direction. The X stage 3 and the Y stage 5 constitute one element of the XY stage.

Reference numeral 7 denotes a stage base. Reference numeral 8 denotes a laser interferometer (first laser interferometer), which uses a mirror 9 fixed on the X stage 3 as a length measurement target.
, That is, the moving state of the X stage 3 is detected. Reference numeral 10 denotes an optical axis assumed by the laser interferometer 8.

[0054] _{11 1, 11 2, ···· 11} n are each temperature measuring means (first temperature measuring means), a vicinity of the optical axis 10, the optical path from the mirror 9 to the laser interferometer 8 It is arranged so that the temperature (temperature distribution) in a plurality of regions inside can be measured.

[0055] _{12 1, 12 2, ···· 12} n are each pressure measuring means (first atmosphere measuring device), a vicinity of the optical axis 10, the optical path extending from the mirror 9 to the laser interferometer 8 Are arranged so that the atmospheric pressure (atmospheric pressure distribution) in a plurality of regions can be measured.

In this embodiment, the Y-axis direction is configured similarly to the X-axis direction.

That is, the laser interferometer 13 detects the position of the Y stage 5 in the Y direction using the mirror 14 fixed on the Y stage 5 as a length measurement target.

Temperature measuring means (first temperature measuring means) 16 ₁
, 16 ₂ ,..., 16 _n are near the optical axis 15,
The temperature (temperature distribution) in a plurality of regions in the optical path from the mirror 14 to the laser interferometer 13 is measured.

Atmospheric pressure measuring means (first atmospheric pressure measuring means) 17
₁ , 17 ₂ ,..., 17 _n measure the atmospheric pressure (atmospheric pressure distribution) in a plurality of areas in the optical path from the mirror 14 to the laser interferometer 13 near the optical axis 15.

In this embodiment, a plurality of points are arranged in the vicinity of the optical path so that the temperature distribution (air pressure distribution) of the air in the optical path in the X and Y directions can be measured by the temperature measuring means (atmospheric pressure measuring means). The number of measuring means (atmospheric pressure measuring means) may be any number depending on the size of the temperature distribution (atmospheric pressure distribution) or the required length measurement accuracy. If the temperature distribution in the X direction (atmospheric pressure distribution) and the temperature distribution in the Y direction (atmospheric pressure distribution) are similar, one of the temperature distributions (atmospheric pressure distribution) may be used as a representative.

Reference numeral 18 denotes a measuring means for directly measuring a change in the refractive index of air or a change in the oscillation wavelength from the laser using a laser interferometer (second laser interferometer). The measuring means 18 is arranged in a space where the stage can be accommodated.

FIG. 3 is a schematic view of a main part of the measuring means 18 in the YZ section.

In FIG. 3, a base 1 made of a low thermal expansion material is used.
The laser interferometer 20 is fixed on the base 9 via an adjustable mount 21.

Similarly, the mirror 22 is fixed to the base 19 via the stand 23. The laser interferometer 20 detects the optical displacement of the mirror 22, and the displacement of the mirror is taken into the control means (26 in FIG. 1). The displacement of the mirror 22 detected here is a change in the refractive index of air and the laser interferometer 2.
This is caused by a change in the oscillation wavelength from zero.

Therefore, the change ΔN in the refractive index N is obtained by dividing the displacement ΔL of the mirror 22 by the optical path length (the length from the mirror 22 to the laser interferometer 20) L.

The change in the oscillation wavelength λ from the laser interferometer 20 can also be obtained from the equation N = λ ₀ / λ. Here, λ ₀ is the oscillation wavelength in vacuum.

In FIG. 3, reference numeral 24 denotes an optical axis assumed by the laser interferometer 20, and a plurality of temperature measuring means (second temperature measuring means) 25a and pressure measuring means (second atmospheric pressure) (Measurement means) 25b.

The influence of temperature and pressure is subtracted from the refractive index change ΔN measured by the laser interferometer 20 by the calculation formula based on the measurement result of the environment measuring means 25, and the refractive index change due to other temperature, gas partial pressure, etc. Seeking.

The acquisition and calculation of these measurement results are performed by the control means 26 of FIG.

In this embodiment, each measured temperature and pressure,
The control means 2 uses the outputs of the laser interferometers 8 and 13.
6, the X, Y stages 3,
5 to determine the correction amount for the movement of the DC servo motor 4,
6, the wafer 1 is positioned at a correct position.

Next, the measuring means 18 of FIG. 3 will be described.

[0072]

[Outside 1]

[0073]

(Equation 1) Becomes Assume that the oscillation wavelength when the laser interferometer 20 is reset is λ, and after a predetermined time elapses, the wavelength becomes λ ′. At this time, if the output from the laser interferometer 20 becomes A, the laser interferometer 20 to the mirror 22 Is L ₁ , and the oscillation wavelength in vacuum is λ ₀

[0074]

(Equation 2)

[0075]

[Outside 2] Here when the Y stage 5 is going to move only ΔY in the Y direction, the temperature measuring means 16 _1, 16 temperature of ₂ · · · · 16 _s is Delta] t _s changed from Delta] t ₁ respectively, pressure measuring means 17 ₁
If the air pressure of 17 ₂ ···· 17 _s is changed from each Delta] p ₁ by Delta] p _n, it is determined by the correction amount as follows.

[0076]

(Equation 3) Therefore, when moving the Y stage 5 by ΔY, (9) or (1)
What is necessary is just to drive-control the Y stage 5 so that it becomes B obtained from equation (0). The same applies to the X direction.

In the present embodiment, the refractive index N is obtained from the temperature, pressure, humidity, gas partial pressure and the like by a theoretical formula. In addition, when absolute accuracy is not required much, high measurement accuracy and stability can be obtained without strictly determining the refractive index N.

In this manner, the change in the refractive index over the entire optical path of the laser interferometers 8 and 13 for position detection is captured, corrected by the correction formula, and the DC servo motors 4 and 6 are driven to move the wafer 1 to the correct position. Is positioned. The correction laser interferometer 20 does not need to be placed near the laser interferometer 13 because the difference from the optical path of the laser interferometer 13 is guaranteed by the environment measuring means 25. In this embodiment, a projection lens (not shown) is used. ) Is provided on the back surface of a lens surface plate (not shown). This place is generally a space where the stage can fit.

FIG. 4 is a schematic view showing a main part of a part of the second embodiment of the present invention, and corresponds to the YZ sectional view of FIG.

FIG. 5 is a schematic view of a main part of the measuring means according to the second embodiment of the present invention, and corresponds to the YZ sectional view of FIG.

In FIGS. 4 and 5, the same elements as those shown in FIGS. 2 and 3 are denoted by the same reference numerals.

In this embodiment, a region on the optical path is assumed to be a region divided at substantially equal intervals, and a temperature measuring unit 16 and a barometric pressure measuring unit 17 are arranged substantially at the center of the region.

[0083]

[Outside 3]

[0084]

(Equation 4) Which of the correction equations of equations (14) to (16) is used is determined depending on the balance with the length measurement accuracy.

The laser interferometer 20 for correction has a wavelength compensator of Zygo which measures differentially in a vacuum and an atmosphere, and mirrors fixed to both end surfaces of a member made of zero joule by HP which measures differentially. There is a wavelength compensator and the like.

As described above, in the first and second embodiments, the laser interferometer 8 for position detection, including the change in the laser oscillation wavelength, is used.
This makes it possible to accurately measure the refractive index of the atmosphere over the entire optical path of No. 13 and to perform highly accurate positioning correction using such a correction formula.

Therefore, the length measurement error due to the change in the refractive index of the atmosphere is substantially zero, and the length measurement stability is also greatly improved. Then, the positioning accuracy of the stage can be improved with high accuracy and stability.

Further, since it is not necessary to provide the laser interferometer 20 for correction near the optical path of the laser interferometers 8 and 13 for position detection, the optical path of the laser interferometers 8 and 13 for position detection can be shortened, and the entire apparatus Can be reduced in size.

Further, by performing correction in real time or for each step of the stage, it is possible to cope with relatively rapid changes in temperature, atmospheric pressure, and the like.

FIG. 6 is a plan view of a main part of a third embodiment of the present invention, and FIG. 7 is a sectional view taken along line AA of FIG.

In FIG. 6, reference numeral 101 denotes a base, and XY
It has a plane portion substantially parallel to the plane. 102 is base 1
1 is a Y stage (first stage) supported by a static pressure gas bearing 103. 104 is a static pressure gas bearing 1
This is a suction magnet for applying a preload to the 03. Reference numeral 105 denotes a Y guide (first guide means), which is attached to the base 101. The Y stage 102 can be moved in the Y direction by the static pressure gas bearing 106 on the side surface of the Y stage 102 and the Y guide 105 as the first guide means. The guide surface provided on the Y stage 102 constitutes second guide means.

Reference numeral 107 denotes a suction magnet for applying a preload to the static pressure gas bearing 106. Y stage 102 is base 10
Two linear motor stators 108 fixed to 1
are driven in the Y direction by two linear motor movers 110 and 110a corresponding to linear motor stators 108 and 108a fixed to both ends of the Y stage 102 via members 109 and 109a.

Here, the linear motor stators 108, 108
a, the linear motor movers 110 and 110a constitute one element of the first driving means.

The linear motor stators 108, 108a and the linear motor movers 110, 110a constitute one element of the first driving means. Linear motor stators 108, 10
8a and the linear motor movers 110, 110a can be independently driven and controlled.

Thus, even if the center of gravity of the Y stage 102 is displaced from the center of the two linear motors, the Y stage 102 and the X stage (the Even if the total center of gravity of the two stages 111 and the top plate (the third stage) 118 is shifted from the center of the two linear motors, the generated force of each linear motor is appropriately distributed according to the position of the center of gravity, so that ω _Z The Y stage 102 can be driven in the Y direction substantially straight without rotating in the Y direction.

Further, the guide rigidity of the Y stage 102 in the ω _Z direction, that is, the rigidity of the hydrostatic gas bearing 106 does not always need to be increased.

The distribution of the power generated by the linear motor is in accordance with the X coordinate of the top plate 118 measured by a laser interferometer, which will be described later. May be changed linearly, or may be changed by a polynomial approximation.

The X stage 111 (second stage) is supported on the base 101 by the hydrostatic bearing 112.
Reference numeral 113 denotes an attraction magnet for applying a preload to the hydrostatic bearing 112. Static pressure bearing 112 provided on X stage 111 and X
The Y stage 1 is located between the bearing 111 and the hydrostatic bearings 115 and 116 provided on a bearing housing 114 fixed to the stage 111.
02 sandwiches the X-direction guide shaft.

Thus, the X stage 111 can move in the X direction with respect to the Y stage 102, and can move in the Y direction together with the Y stage 102. To move the X stage 111 in the Y direction, the X stage 111 receives a hydrostatic bearing force from the X direction guide shaft of the Y stage 102. This driving point and (the point where the resultant force occurs when there are a plurality of hydrostatic bearings) X If the position of the center of gravity of the stage does not match, when the X stage 111 is moved in the Y direction, an undesirable rotation is generated in the ω _Z direction.

This is not preferable as in the case of the Y stage 102. For the Y stage 102, the problem is solved by distributing the generated forces of the two linear motors. However, for the X stage 111, the mounting positions of the hydrostatic bearings 115 and 116 with respect to the X stage 111 can be adjusted. The center of gravity of the X stage 111 can be driven,
The motor can be moved in the Y direction without causing undesired rotation in the ω _Z direction.

The member 117 fixed to the X stage 111
A plurality of elastic members 120 as third guide means are provided radially around the center of the top plate 118 in a plane substantially parallel to the XY plane between the member 119 and the member 119 fixed to the top plate 118. The elastic member 120 may be a thin rod-shaped member that is rigid in the axial direction and soft in the other direction.

In this embodiment, the thick rod-shaped member is provided with constricted portions in two places, so that it has rigidity in the axial direction and softness in the other direction.

The X stage 11
The top plate 118 can move in the Z direction, ω _X , ω _Y , ω _Z directions with respect to 1.

A hinge member 122 which is rigid in the expansion and contraction direction and flexible in rotation about an axis perpendicular to the expansion and contraction direction is provided at each end of the piezo actuator 121 in the expansion and contraction direction.

In this embodiment, the hinge member 122 is a rod-shaped member provided with a constricted portion. The hinge member 122
Of the two ends, one end to the X stage 112 and the other end to the top plate 11
Fix to 8.

[0106] Three such actuators 121 are provided, each of which can be driven independently. Therefore, X
The top plate 118 with respect to the stage 112 Z, ω _X, is drivable omega _Y direction of the other in the rigid in the X, Y, and soft in the omega _Z direction.

In order to make it easier to attach the hinge member 120, the attachment surfaces of the members 117 and 119 are preferably processed substantially parallel to the XY plane.

On the member 117, a Z-direction displacement sensor 123 is provided.
(Position sensors) are provided, and the sensor 1
A measurement target (detection target) 124 for the position detecting means facing the position 23 is arranged, and Z, ω
_X and ω _Y are calculated.

Based on this, the piezo actuator 121
With thereby enabling positioning the location of the desired Z, ω _X, ω _Y. Piezo actuator 121 and hinge member 1
22 constitutes a third driving means.

The Y stage 102 is provided with two linear motors (stators) 125 and 125a, and two corresponding linear motors (movers) 126 and 126a are fixed to the top plate 118. Linear motors 125, 12
5a, 126, 126a constitute one element of the second driving means.

The two linear motors can be controlled independently, and the top plate 118 is moved with respect to the Y stage 102 by X, ω _Z
It can be driven in any direction. Even if the centers of the two linear motors do not coincide with the center of gravity of the top plate 118, undesired rotation in the ω _Z direction occurs by distributing the generated forces to the two linear motors as in the case of the Y stage 102. I try not to.

Since there is a gap between the linear motor stators 125 and 125a and the linear motor movers 126 and 126a, the top plate 118 is free in the Z, ω _X and ω _Y directions.

As described above, the linear motors 125, 125
a, 126, 126a and the piezo 121 respectively move the top plate 118 to X, Z, ω _X , ω _Y , ω without interfering with each other.
_It can be driven in the _Z direction.

Since the top plate 118 is rigidly connected to the X stage 111 in the XY directions, when the Y stage 102 is driven in the Y direction, the X stage 111 and the Y stage 102 are moved together with the X stage 111 and the Y stage 102 via the elastic hinge 120. Driven in the direction. X stage 111 has elastic hinge 12
It is driven in the X direction together with the top plate 118 via the “0”.

An object 128 to be positioned is placed on the top plate 118 via a chuck 127. Object 12
8 of XY, positions of the omega _Z direction is detected by the mirror (detection target) 129 and 130 and the laser interferometer 131, 132, 133 secured to the top plate 118. The laser interferometers 131 and 132 constitute one element of the position detecting means. Laser interferometers 131 and 132 constitute one element of the angle detecting means.

The ω _Z direction is detected by calculating the difference between the two laser interferometers 131 and 132 for measuring the X direction. The ω _Z direction may be detected using a differential angle measuring interferometer. Also in the ω _X and ω _Y directions, two points obtained by offsetting the mirrors 129 and 130 in the Z direction may be measured by an angle measuring interferometer.

In this case, three sets of the displacement sensor 123 and the target 124 are not required, and one set may be used.

If a measuring device for measuring Z, ω _X , ω _Y when the positioning object 128 is to be positioned is provided,
The deviation between the position information of Z, ω _X , ω _Y and the target position of the measuring device is driven on the measured values of the angle measuring interferometer of ω _X , ω _Y and one set of displacement sensors or three sets of displacement sensors. What is necessary is just to position it.

Although the static pressure bearing uses air, an air supply gas can be used according to the atmosphere around the stage. For example, in the N ₂ atmosphere, supply gas is nitrogen (N ₂ )
You can also

In this embodiment, with the above-described configuration, the deviation between the image plane and the laser optical axis with respect to the object, that is, the Abbe error is made substantially zero.

FIG. 8 is a sectional view of a main part of a fourth embodiment of the present invention.

In this embodiment, the actuator comprising the piezo element 121 and the elastic hinge 122 is replaced with a linear motor as compared with the third embodiment. Then, by applying servo to the linear motor, appropriate rigidity is set in the driving direction, and flexibility is given in other directions.

In FIG. 8, three linear motors (134, 136) that can be controlled independently are connected to the X stage 111 and the top 1
18 is provided. Reference numeral 134 denotes a linear motor mover, which is fixed to the top plate 118 via a heat insulator 135. Reference numeral 136 denotes a linear motor stator,
And is fixed to the X stage 111 via.

Generally, it is desirable that the mover be lightweight,
In the present embodiment, the mover 134 is on the coil side,
Is on the magnet side, but may be reversed.

In the present embodiment, the heat generation of the linear motor is sufficiently taken into consideration and is fixed via a heat insulating material. However, in order to further suppress the thermal deformation of the X stage 111 and the top plate 118, the temperature is controlled using a refrigerant. Is good. In order to reduce the load on the linear motor and the heat generation, the stationary force applied to the linear motor, that is, the weight of the top plate, is relatively weak in the Z direction provided on the member 138 and is in the other direction (X, Y). , Ω _X , ω _Y , ω _Z ) by the coil spring 139 having very low rigidity.
I support.

[0126] The coil spring 139 is provided in plural, has reference height positioning object _{(Z, ω X, ω Y} ) and adjustable so that load on the linear motor when the positioning is minimized. When the number of coil springs 139 is one, it is better to arrange so as to support the center of gravity of the top plate 118.

The coil spring 139 can be replaced with a magnet. One is fixed to the member 138 and the other is fixed to the top plate 118 so that the two magnets repel each other. A plurality of sets are provided as one set.

Thus, Z, ω _X ,
ω _Y direction can be adjusted. The same applies to the case where one set is used. At this time, since the generated force of the coil spring or the magnet can change with time, the generated force can be adjusted from the outside. Further, a drive means such as a pulse motor may be mounted to automatically adjust.

This is effective when the top plate 118 moves particularly largely in the Z direction, and can cancel the force generated due to the balance between the displacement in the Z direction and the rigidity of the coil spring or the magnet, and reduce the load on the linear motor. doing.

[0130] Z a relatively wide range of movement of the three linear motors, omega _X, omega _Y direction may largely driven but, Z in order to take advantage of the benefits enough, omega _Z direction hydrostatic gas bearing (115, 116), and the ω _X and ω _Y directions are preferably guided by a leaf spring-like elastic member.

The member 141 is different from the cylindrical guide member (first guide member) 140 fixed to the top plate 118 with respect to the static pressure gas bearing 1 provided on the member (second guide member) 141.
42.

For the member 141, the top plate 118 is Z, ω _Z
It can move in any direction. Further, the member 141 is the X stage 1
11 in a plane substantially parallel to the XY plane, the member 138 fixed radially around the XY center of the top plate 118.
Are connected by a leaf spring 143 which is flexible in the directions and rigid in the XY directions. The member 141 with respect to the X stage 111 has Z, ω _X ,
It can move in the ω _Y direction.

By doing so, the X stage 111
The top plate 118 with respect to the Z, ω _X, ω _Y, is movable in the omega _Z direction. Since the Z-direction is supported by the hydrostatic bearing 142, the force for deforming the top plate 118 naturally does not act even if it moves with a large stroke. Since the allowance is provided in the Z direction, it is not necessary to allow the leaf spring 143 to take a stroke in the Z direction, and the strokes in the ω _X and ω _Y directions can be expanded.

Since the member 141 can be moved in the Z direction although it is very small, if there is a possibility of vibration during the positioning operation,
It is desirable to provide a damper for damping the vibration of the member 141 in the Z direction.

In this embodiment, the vibration damping rubber 144 is inserted between the member 141 and the bearing housing 114. This can be replaced with a dashpot.

The XY rigidity in the connection between the X stage 111 and the top plate 118 is mainly determined by the rigidity of the static pressure bearing 142, the rigidity of the moment, the XY rigidity of the leaf spring 143, and the like. The relative vibration between the stage 111 and the top plate 118 in the XY directions becomes a problem.

Therefore, it is preferable to provide a damper in the X and Y directions between the X stage 111 and the top plate 118. Also, a damper may be provided only in the above-mentioned portion that is not sufficient in rigidity.

As described above, in the third and fourth embodiments, the structure conventionally required for each actuator and guide can be eliminated, and the stage weight can be remarkably reduced, thereby shortening the positioning time and reducing the time required for the actuator. Can be reduced.

In the XY-direction actuators, two independently controllable actuators are provided, and by appropriately distributing the generated force, the position of the center of gravity can be driven, and rotation (vibration) that extends the positioning time is suppressed. be able to.

Also, by allowing the bearing mounting position to be adjustable for the portion driven via the bearing of the guide, the center of gravity of the stage can also be driven, thereby shortening the positioning time. doing.

[0141]

According to the present invention, by setting each element as described above, (4-1) in an optical path from an XY stage on which a wafer is mounted to a laser interferometer in a projection exposure apparatus or the like for manufacturing a semiconductor device. XY stage movement control, that is, a positioning device capable of performing positioning with high accuracy without being adversely affected by these environmental changes even if the temperature distribution of the XY stage is not constant or the ambient air pressure changes variously. And a method for manufacturing a semiconductor device using the same.

(4-2) By appropriately configuring each element for driving and controlling a stage on which a wafer as an object is mounted, the wafer can be precisely positioned at a predetermined position while simplifying the entire apparatus. A positioning device capable of positioning and a method for manufacturing a semiconductor device using the positioning device can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is a YZ sectional view of a part of FIG.

FIG. 3 is an explanatory view of a part of FIG. 1;

FIG. 4 is a schematic diagram of a main part of a part of a second embodiment of the present invention.

FIG. 5 is a schematic diagram of a main part of a part of a second embodiment of the present invention.

FIG. 6 is a plan view of a main part of a third embodiment of the present invention.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a sectional view of a main part of a fourth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 wafer 2 chuck 3 X stage 4 DC servo motor 5 Y stage 6 DC servo motor 7 stage base 9, 14 mirror 10, 15 optical path 11, 16 thermometer 12, 17 barometer 18 correction laser interferometer means 19 base Reference Signs List 20 laser interferometer 21 adjustable mount 22 mirror 25 thermometer / barometer 26 arithmetic / control device 101 base 102 Y stage 103 static pressure bearing 104 attracting magnet 105 Y guide 106 static pressure bearing 107 attracting magnet 108 Y linear motor (stator) 109 Connecting member 110 Y linear motor (movable element) 111 X stage 112 Static pressure bearing 113 Attraction magnet 114 Bearing housing 115 Static pressure bearing 116 Static pressure bearing 117 Support member 118 Top plate 119 Support member 120 Elastic hinge member 121 Piezo 12 Elastic hinge members 123 displacement sensor 124 a displacement sensor target 125 X linear motor (stator) 126 X linear motor (mover) 127 chuck 128 positioned object 129 X mirror 130 Y mirrors 131 X interferometer 132 omega _Z interferometer 133 Y interferometer Total 134 Linear motor mover 135 Heat insulator 136 Linear motor stator 137 Heat insulator 138 Support member 139 Coil spring 140 Guide shaft 141 Bearing member 142 Static pressure bearing 143 Leaf spring

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-256611 (JP, A) JP-A-3-97216 (JP, A) JP-A-2-1501 (JP, A) JP-A-60-1985 79358 (JP, A) JP-A-2-201913 (JP, A) JP-A-2-68609 (JP, A) JP-A-4-72712 (JP, A) JP-A-64-70734 (JP, A) JP-A-6-302498 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/027

Claims (25)

(57) [Claims] An object to be aligned is placed, a mirror is provided on a part of an XY stage that moves in an XY plane, and laser light from a first laser interferometer is incident on the mirror.
A positioning device that controls the positioning of the XY stage by control means using the laser light via the mirror;
A first temperature measuring means for measuring a temperature distribution in the optical path in an optical path from the first laser interferometer to the mirror;
A second laser interferometer is provided at a location where the air conditioning is substantially the same as that of the XY stage, and a second temperature measuring means for measuring a temperature distribution in the optical path is provided in an optical path of the second laser interferometer. The control means uses the signals from the second laser interferometer and the second temperature measurement means to remove the temperature effect from the second laser interferometer.
A change in the oscillation wavelength from the laser interferometer is calculated, and the effect of the change in the oscillation wavelength included in the signal obtained by the first laser interferometer is calculated using the calculation result and the signal from the first temperature measuring means. A positioning device which calculates and corrects the position of the XY stage based on the calculation result to reduce the influence of a change in oscillation wavelength from the first laser interferometer. 2. The second laser interferometer and the first and second laser interferometers.
The positioning device according to claim 1, wherein the temperature measuring means is provided in at least one of the XY directions. 3. An object to be positioned is placed, a mirror is provided on a part of an XY stage that moves in an XY plane, and a laser beam from a first laser interferometer is incident on the mirror.
A positioning device that controls the positioning of the XY stage by control means using the laser light via the mirror;
In the optical path from the first laser interferometer to the mirror, first temperature measuring means for measuring the temperature distribution in the optical path and first pressure measuring means for measuring the pressure distribution are substantially similar to the XY stage. A second laser interferometer in the same air-conditioned location, a second temperature measuring means for measuring the temperature distribution in the optical path in the optical path of the second laser interferometer, and a second temperature measuring means for measuring the pressure distribution; Are respectively provided, and the control means includes the second laser interferometer, the first and second temperature measuring means, and the first and second temperature measuring means.
Using the signal from the second atmospheric pressure measuring means, the influence of the change in the oscillation wavelength included in the signal obtained by the first laser interferometer is calculated, and the position of the XY stage is corrected based on the calculation result. A positioning device wherein the influence of a change in oscillation wavelength from the first laser interferometer is reduced. 4. The second laser interferometer and the first and second laser interferometers.
4. The positioning device according to claim 3, wherein the temperature measuring means and the first and second air pressure measuring means are provided in at least one of the XY directions. 5. A method of manufacturing a semiconductor device, comprising: performing relative position detection between a reticle and a wafer; transferring a pattern on a reticle surface to a wafer surface; and manufacturing the semiconductor device through a developing process on the wafer. In the method, the wafer is mounted, a mirror is provided on a part of an XY stage moving in an XY plane, a laser beam from a first laser interferometer is incident on the mirror, and the laser beam is transmitted through the mirror. Use XY
When the positioning of the stage is controlled by the control means, the first
A first temperature measuring means for measuring a temperature distribution in the optical path in an optical path from the laser interferometer to the mirror, a second laser interferometer in a place where substantially the same air conditioning as the XY stage is performed, In the optical path of the second laser interferometer, second temperature measuring means for measuring the temperature distribution in the optical path are provided, and the control means controls the second laser interferometer and the second temperature measuring means. The change in the oscillation wavelength from the second laser interferometer excluding the influence of the temperature is calculated using the signal of (1), and the first laser interferometer is calculated using the calculation result and the signal from the first temperature measuring means. Calculating the effect of the change in the oscillation wavelength included in the signal obtained in step 1, and correcting the position of the XY stage based on the calculation result to reduce the effect of the change in the oscillation wavelength from the first laser interferometer. A method of manufacturing a semiconductor device, comprising: 6. A method of manufacturing a semiconductor device, comprising: performing relative position detection between a reticle and a wafer; transferring a pattern on a reticle surface to a wafer surface; and manufacturing the semiconductor device through the developing process of the wafer. In the method, the wafer is mounted, a mirror is provided on a part of an XY stage moving in an XY plane, a laser beam from a first laser interferometer is incident on the mirror, and the laser beam is transmitted through the mirror. Use XY
When the positioning of the stage is controlled by the control means, the first
In the optical path from the laser interferometer to the mirror, a first temperature measuring means for measuring a temperature distribution in the optical path and a first air pressure measuring means for measuring the atmospheric pressure distribution are provided in substantially the same air conditioning as the XY stage. A second laser interferometer at a location where the measurement is performed, a second temperature measuring means for measuring a temperature distribution in the optical path in the optical path of the second laser interferometer, and a second atmospheric pressure for measuring the atmospheric pressure distribution. Measuring means are respectively provided, and the control means obtains the signals by the first laser interferometer using signals from the second laser interferometer, the first and second temperature measuring means, and the first and second air pressure measuring means. Calculating the effect of the change in the oscillation wavelength included in the obtained signal, and correcting the position of the XY stage based on the calculation result,
A method of manufacturing a semiconductor device, wherein the influence of a change in oscillation wavelength from the first laser interferometer is reduced. 7. A base having a flat portion substantially parallel to the XY plane, a first supported on the flat portion of the base by a hydrostatic gas bearing, and moved along the flat portion in the Y direction by first guide means. Stage, a first driving the first stage
A hydrostatic gas bearing on a plane portion of the base movable in the X direction along the plane portion and in the Y direction along with the first stage by a driving means and a second guide means provided on the first stage; The second stage supported by the second stage and the third guide means in the Z direction and X
Third stage rotatable in the directions of the axes Y, Z, and Z;
Second drive means provided on the stage for moving the second stage in the X-axis direction and rotating about the Z-axis with respect to the first stage, and for the second stage provided on the second stage A third drive means for moving the third stage in the Z-axis direction and rotating around the X-axis and the Y-axis is used to position an object provided on the third stage. Positioning device. 8. A position detecting means arranged substantially parallel to an XY plane and arranged so that an Abbe error with respect to the object becomes substantially zero.
8. The positioning apparatus according to claim 7, further comprising: a detection target for said position detection means provided on said third stage; and an angle detection means for detecting an angle of said detection target. 9. The positioning apparatus according to claim 8, wherein said position detecting means and said angle detecting means comprise a laser interferometer, and said detection target comprises a reflecting mirror. 10. The angle detecting means detects a position other than the position detected by the position detecting means, and calculates an angle from a difference between the position and the position detected by the position detecting means. The positioning device according to claim 9, wherein: 11. The positioning apparatus according to claim 7, wherein said first guide means comprises a guide member provided on said base in the Y direction and a hydrostatic gas bearing provided on said first stage. . 12. The guide member is made of a magnetic material,
The positioning device according to claim 11, wherein a suction force is exerted by a magnet provided on the first stage. 13. The method according to claim 13, wherein the first driving means is driven in the Y direction by using two actuators each of which can control two locations offset in the X direction with the center of gravity of the first stage sandwiched therebetween. The positioning device according to claim 7. 14. The apparatus according to claim 7, wherein said second guide means comprises a guide member provided on said first stage in the X direction and a hydrostatic gas bearing provided on said second stage. Positioning device. 15. A cylindrical first guide member fixed to the third stage for guiding rotation in the Z direction and around the Z axis, a second guide member opposed to the first guide member, A static pressure gas bearing provided on one of the first guide member or the second guide member and supporting the other; an elastic member rigidly connecting the second guide member and the second stage at least in the X direction or the Y direction; The positioning device according to claim 7, further comprising: 16. The elastic member is substantially parallel to an XY plane and has a Z
16. The positioning device according to claim 15, wherein the positioning device is a leaf spring that is flexible in the direction, around the X axis, and around the Y axis. 17. The positioning device according to claim 16, wherein a Z-direction damper is inserted between said second guide member and said second stage. 18. The third guide means has a plurality of rod members which are rigid in the axial direction and are flexible in the other direction, or a plurality of hinge members each having a plurality of constrictions in the rod members, and passes through the axis of the hinge member. Each virtual straight line is radially arranged around an XY center of the third stage in a plane substantially parallel to the XY plane, and one end of the hinge member is connected to the second stage and the other end is connected to the third stage. And the third stage is connected to the second stage so as to be rigid in the X and Y directions and to be flexible in the Z direction, around the X axis, around the Y axis, and around the Z axis. The positioning device according to claim 7, wherein: 19. The second driving means uses two actuators, each having a center of gravity interposed between the third stage and being offset in the Y direction and capable of controlling two positions, in the X direction and the Z direction.
8. The positioning device according to claim 7, wherein the positioning device is driven to rotate about an axis. 20. The positioning device according to claim 19, wherein said actuator is a linear motor. 21. An actuator comprising: a piezo element; and a hinge member which is attached to both ends of the piezo element in a direction in which the piezo element expands and contracts and which is flexible about an axis perpendicular to the direction of the expansion and contraction. The three stages are arranged between the stage and the third stage so that the direction of expansion and contraction of the actuator is substantially in the Z direction, and the third stage and the second stage are arranged in the Z direction, around the X axis, and around the Y axis. The positioning device according to claim 7, wherein the positioning device is driven. 22. The positioning device according to claim 21, wherein said actuator is a linear motor. 23. A position sensor for detecting three positions in the Z direction of the third stage, or one position sensor and two position sensors for detecting the Z stage, around the X axis and around the Y axis of the third stage. 22. The positioning device according to claim 21, wherein positioning of the third stage in the Z-axis direction, around the X-axis, and around the Y-axis is performed by providing an angle sensor. 24. The positioning apparatus according to claim 21, wherein said third stage is supported by a support means which is rigid in the Z direction and flexible in the other direction. 25. The positioning device according to claim 24, wherein said supporting means uses a repulsive force of a coil spring or a magnet.