JP2003179122A - Wafer inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute a substrate inspection device that has driving shafts in two orthogonal axial directions and inspects a substrate by moving the substrate and the observational visual field of an optical system provided for observing the substrate relatively to each other, to make it small in size. <P>SOLUTION: A drive device 1 is provided with X- and Y-shaft drive mechanism 10 and 20, which move a table 41 in orthogonal X and Y directions and a controller 5 which controls the operations of the drive mechanism 10 and 20. The controller 5 positions the chip region of a wafer W in the visual observation field of the optical system 50 for optical measurement by moving the table 41 through the control of the operations of the drive mechanism 10 and 20. The wafer W is held on the table 41, in a state with the wafer W inclined by a prescribed angle, with respect to the X and Y-shafts. The controller 5 positions the wafer W in the visual observation field of the optical system 50, by moving the table 41 by means of operating the drive mechanisms 10 and 20 within a drive range, in which the moving ranges of the shafts are smaller than the diameter of the wafer W. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device and a driving method for moving and positioning an object member or an optical system in two axial directions orthogonal to a base of the device.

[0002]

2. Description of the Related Art Examples of conventional devices of this type include overlay measuring machines for inspecting substrates, visual inspection devices, and micro
There are inspection devices such as macro inspection devices.

The overlay measuring device is a multilayer semiconductor device manufacturing process in which a plurality of circuit pattern layers are stacked in the thickness direction of a semiconductor wafer to form a circuit, and the circuit pattern formed in the previous exposure step and the next step. It is a measuring machine for inspecting the state of superposition with the circuit pattern formed in the exposure step of.

In such an inspection apparatus, in addition to an apparatus having a drive mechanism for moving and positioning a table holding an object member in the X-Y axis direction, a table holding an object is fixed and a measurement optical system is fixed. With a drive mechanism for moving and positioning the X-axis in the X-Y axis direction, or a table holding an object is moved in either the X-axis or the Y-axis direction and the measurement optical system is orthogonal to the drive axis of the table. There is a device provided with a drive mechanism for moving in another uniaxial direction.

[0005]

In the case of an overlay measuring machine, for example, in order to accurately move and position the overlay mark on the wafer surface within the visual field of the measurement optical system, the position on the wafer surface must be adjusted. Need to be identified. Therefore, in the process of inspecting the semiconductor wafer, the center position W0 of the wafer W and the notch N formed in the wafer W as shown in FIG.
(Or orientation flat) is used as a reference to define a Cartesian coordinate system consisting of xy axes on the wafer W surface, and the position of each chip area 101 to 1 mn on the wafer W surface and the position of the overlay mark in each chip area. Is specified by the coordinate P1mn (x, y) in this rectangular coordinate.

In the overlay measuring machine, the azimuth angle direction of the notch N of the semiconductor wafer W and the center position of the wafer W are finely adjusted before starting the overlay measurement, and the x− of the wafer W is measured.
The y axis is aligned so as to coincide with the XY axis of the XY stage (see the two coordinate axes additionally shown in FIG. 6). Then, the semiconductor wafer W thus aligned is moved to a predetermined coordinate position on the XY stage. In the overlay measuring machine, it is often the case that the measurement is not performed in all the chip areas but only in a part of the chip areas. In this case, the measurement is often performed in the chip area around the wafer W. For example, in FIG.
Consider a case where measurement is performed in the chip areas 101, 168, 125, and 134. When the position of the measurement optical system is fixed and the stage holding the wafer W is moved in the XY axis directions, in order to move both the chip regions 125 and 134 to the observation visual field position of the measurement optical system in order. Is the X of the stage
The moving range in the axial direction needs to be about the diameter of the wafer W. Therefore, the size of the stage in the X-axis direction needs to be about twice the diameter of the wafer W. This also applies to the Y-axis direction. The size of the wafer tends to increase, and the conventional configuration has a problem that the inspection apparatus also increases in size as the size of the wafer increases. If the equipment becomes large, the clean room also has to be made large, resulting in high cost.

It is an object of the present invention to provide a substrate inspection device which can prevent the size of the device from increasing.

[0008]

[Means for Solving the Problems] In order to solve the above problems,
In the substrate inspection apparatus of the invention according to claim 1, the table holding the substrate, the optical system having an observation field of view of a part of the substrate, and the positional relationship between the table and the observation field of view of the optical system are orthogonal to each other. In a substrate inspection apparatus including a first shaft and a drive unit that relatively moves in a second axial direction, the substrate inspection device includes a third axis and a fourth axis which are orthogonal to each other with a predetermined position on the substrate as a reference. The substrate is held on the table in a state where the direction of the coordinate axis for indicating the position on the substrate and the directions of the first axis and the second axis have an inclination, and the observation field of view is It is characterized in that it can be moved by the driving means only inside a quadrangle connecting four points where the third axis and the fourth axis intersect the outer circumference of the substrate.

According to a second aspect of the present invention, there is provided a substrate inspection apparatus which has a table for holding a substrate, an optical system for observing part of the substrate as an observation visual field, and a positional relationship between the table and the observation visual field of the optical system. In a substrate inspection apparatus including a first axis and a drive means for relatively moving the first axis and the second axis that are orthogonal to each other,
The direction of the coordinate axis for indicating the position on the substrate, which is composed of the third axis and the fourth axis orthogonal to each other with respect to the predetermined position on the substrate, and the first axis and the second axis. Direction and
The substrate is held on the table in a tilted state,
Further, the relative movement range of each of the first axis and the second axis is shorter than the diameter of the substrate.

A board inspection apparatus according to a third aspect of the present invention is the board inspection apparatus according to the first or second aspect, wherein:
The driving means has an image capturing means for capturing an image formed by the optical system as an image, and the driving means provides a mark indicating a superposition state of a plurality of pattern layers provided on the surface to be inspected of the substrate of the optical system. The image capturing means is positioned within an observation visual field, and the image capturing means captures the image of the mark as an image and detects the overlapping state based on the image.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. As an example of the board inspection apparatus according to the first embodiment of the present invention, an overlay measuring machine is shown in FIG. 1, and the overlay measuring machine will be described with reference to this figure.

The overlay measuring machine mainly has a table 41 for sucking and holding a semiconductor wafer (hereinafter referred to as a wafer) W.
A drive unit 1 for moving and positioning the wafer W with respect to the body of the measuring machine, and an overlay mark on the surface of the wafer W mounted on the body above the drive unit 1 and positioned by the drive unit 1. Measuring optical system 50 for measurement
And a control device 5 for controlling the operation of the drive device 1 and the measurement optical system 50. The control device 5 operates the drive device 1 based on a preset control program to move the overlay mark on the surface of the wafer W held on the table 41 into the observation visual field of the measurement optical system 50.
The positioning is performed and the measurement optical system 50 is controlled to measure the superposition state of the superposition marks. In addition,
In the present embodiment, the coordinate system of the overlay measuring machine is indicated by X, Y, and X coordinate axes in the figure.

The drive unit 1 includes a base B fixed to the body of the overlay measuring machine, and an X stage 11 for the base B.
X-axis drive mechanism 10 that horizontally moves the Y stage 21 in the X-axis direction, and Y-axis drive mechanism 20 that horizontally moves the Y stage 21 in the Y-axis direction that is orthogonal to the X-axis with respect to the X stage 11.
1 for the Z stage 31 which is orthogonal to the XY plane.
The Z-axis drive mechanism 30 moves up and down in the axial direction, and the θ-axis drive mechanism 40 rotates the table 41 horizontally with respect to the Z stage 31 in a plane parallel to the XY axis plane.

The X-axis drive mechanism 10 supports an X stage 11 slidably movable with respect to the base B only in the X-axis direction.
It is composed of an axis guide structure, an X-axis drive structure for moving and stopping the X stage 11 with respect to the base B, an X-axis position detector for detecting the position of the X stage 11 in the X-axis direction with respect to the base B, and the like.

The Y-axis drive mechanism 20 is a Y-axis guide structure for slidably supporting the Y stage 21 only in the Y-axis direction with respect to the X stage 11, and moves and stops the Y stage 21 with respect to the X stage 11. And a Y-axis position detector for detecting the position of the Y stage 21 with respect to the X stage 11.

The Z-axis drive mechanism 30 is a Z-axis guide structure that supports the Z stage 31 so that it can be moved up and down only in the vertical direction with respect to the Y stage 21, and the Z stage 31 is finely moved up and down with respect to the Y stage 21. It is composed of an axis drive structure, a Z-axis position detector that detects the height position of the Z stage 31 with respect to the Y stage 21, and the like.

Since the guide structure, the drive structure, the position detector, etc. in the drive mechanisms 10, 20, 30 for each axis are configured in substantially the same manner, the outline of each structure of the X-axis drive mechanism 10 will be described below. With respect to the drive mechanism of each of the other axes, the same members are denoted by the same reference numerals and description thereof is omitted (for example, the servo motor of each drive axis is the X-axis motor 1).
5, Y-axis motor 25 and Z-axis motor 35).

The X-axis guide structure has left and right guide rails 12 attached to the base B and extending in the X-axis direction, and bearings that are fitted to the guide rails 12 and are slidable in the extending direction of the guide rails 12. (Not shown) and
The X stage 11 is attached to the bearing, and the X stage 11 is supported so as to be linearly movable in the X axis direction.

The X-axis drive structure is stretched over the base B so that the X-axis drive structure is
It comprises a ball screw 13 extending in the axial direction, a bearing (not shown) attached to the X stage 11 and fitted to the ball screw 13, and a servomotor 15 connected to one end of the ball screw 13 via a coupling. By controlling the rotation of the servo motor 15, the X stage 11 is linearly moved along the guide rail 12 at a predetermined moving speed.

As the X-axis position detector, a detector using magnetic means, optical means or the like is used. For example, a scale attached to the base B and a detector attached to the X stage 11 serve as the base B. The position of the X-axis stage 11 with respect to is detected.

The X-axis drive mechanism 10 configured as described above
The Y-axis drive mechanism 20 and the Y-axis drive mechanism 20 constitute a so-called XY stage, and by moving the X stage 11 and the Y stage 21 relative to the base B in the respective axial directions, the wafer W held on the table 41. In the composition direction,
It is a drive mechanism for moving and positioning the measurement position on the surface of the wafer W so that the measurement position is within the observation visual field of the measurement optical system 50. The movement strokes of the X stage 11 and the Y stage 21 are set to be larger than the diameter of the wafer W,
An arbitrary position on the entire surface of the wafer W can be moved and positioned on the measurement optical axis L of the measurement optical system 50.

Further, the Z-axis drive mechanism 30 changes the height position of the upper surface of the table 41 with respect to the base B to change the height position of the wafer W surface with respect to the measurement optical system 50, and the wafer to be measured. This is an adjustment mechanism for fine adjustment so that the W surface comes to the focal plane of the measurement optical system 50. The Z-axis drive mechanism 30 is an automatic alignment optical system 8 described later.
The raising / lowering operation is controlled based on the detection signal of 0.

The θ-axis drive mechanism 40 includes a bearing structure that supports the table 41 so that the table 41 can be horizontally swung with respect to the Z stage 31, a servo motor 45, a worm gear mechanism, and the like.
Rotate the table 41 with respect to the stage 31 θ
It is composed of an axis drive structure, a turning angle detector such as a rotary encoder that detects a turning angle position of the table 41 with respect to the Z stage 31, and the like. A holding structure for vacuum-sucking and holding the wafer W is provided on the upper surface of the table 41, and the wafer W held on the table is horizontally swung 360 degrees so that positioning can be stopped at an arbitrary swiveling angle position.

The control device 5 includes each axis drive mechanism 10, 20,
Position detection signals in the respective axial directions are input from the position detectors 30 and 40, and the control device 5 detects the position of the table 41 with respect to the base B and the turning angle position of the table 41 from these detection signals. , X-axis, Y-axis, Z based on the set control program and these detection signals
A command signal is output to each servo motor 15, 25, 35, 45 for the axis and the θ axis. Each axis drive mechanism 10, 20, 30, 4
0 indicates the moving direction and moving speed according to the command signal.
1 is moved to position and stop the table 41 at the commanded stop position.

In the overlay measuring machine of this embodiment, a measuring optical system mounting frame (not shown) is provided so as to straddle the upper side of the driving device 1, and the measuring optical system 50 is mounted on this measuring optical system mounting frame. The optical axis of the measurement optical system 50 is aligned so that the measurement optical axis L is orthogonal to the wafer W surface. The base end of the measuring optical system mounting frame is fixed to the machine body of the measuring machine, and is integrally connected to the base B of the drive unit 1 via the machine body.

Then, the measuring optical system 5 is driven by the driving device 1.
The overlay mark positioned in the observation field of view 0 is observed by the measurement optical system 50.

As shown in FIG. 2, the measuring optical system 50 comprises an illumination optical system and an image forming optical system, and the surface of the wafer W is positioned at the focal plane of the measuring optical system 50. The autofocus optical system 80 that operates the elevating mechanism 15 and finely adjusts the height position of the rotary table 10,
It is provided integrally.

The autofocus optical system 80 includes an AF light source 81 for emitting illumination light having a wavelength different from that of the light source 61 of the measurement optical system, a collector lens 82, a slit 83, a half mirror 84, a condenser lens 85, and light from the AF light source. A dichroic mirror 71 that superimposes and separates the illumination light from the illumination light source 61, an objective lens 72, a relay lens 88, a cylindrical lens 89, and a one-dimensional image sensor 90.

In the autofocus optical system 80, the light from the AF light source 81, which emits the illumination light having a wavelength different from that of the light source 61 of the measurement optical system, is collected by the collector lens 82 and the slit 8.
3, the light enters the dichroic mirror 71 through the half mirror 84 and the condenser lens 85, is reflected by this mirror, and enters the wafer W surface coaxially with the measurement optical axis L through the objective lens 72. The light reflected by the surface of the wafer W returns through the optical path and is reflected by the half mirror 84 to be guided to the autofocus light receiving system. In the autofocus light receiving system,
The light reflected by the half mirror 84 enters the pupil division prism 87 arranged at the pupil conjugate position of the objective lens 72 via the relay lens 86, and the light branched by this prism is divided by the relay lens 88 into two light beams. Form a slit image.
The cylindrical lens 89 condenses and compresses the longitudinal direction of this slit image to form an image on the one-dimensional image sensor 90.

The image signal of the slit image photoelectrically converted by the one-dimensional image pickup device 90 is input to the AF processing device 95, and the AF processing device 95 determines the wafer from the focus position of the objective lens 72 based on the interval between the two slit images. The shift amount in the height direction of the W surface is calculated. Then, a correction signal for correcting this deviation amount is output to the control device 5 to operate the elevating mechanism 15 so that the wafer W surface comes to the focus position of the objective lens, in other words, the measurement optical system 50 is brought into a focused state. Auto focus control is performed so that When the in-focus state is achieved by the autofocus control, the measurement optical system 50 measures the overlay mark.

The measurement optical system 50 includes a light source 61 for illuminating the wafer W surface, a collector lens 62, a bandpass filter 63 for transmitting only light in a predetermined wavelength band, and a relay lens 6.
4, aperture stop 65, relay lens 66, field stop 67,
Condenser lens 68, half mirror 69, illumination light source 6
1, a dichroic mirror 71 for superposing and separating the illumination light from the AF light source 81 and the light from the AF light source 81, an objective lens 72, an imaging lens 73, a two-dimensional image pickup device 74 such as a CCD (charge coupled device), and image processing. The device 75 and the like are included.

In the measurement optical system 50, the illumination light from the light source 61 passes through the collector lens 62, the bandpass filter 63, the relay lens 64, the aperture stop 65, the relay lens 66, the field stop 67, and the condenser lens 68, and the half mirror 69. And is transmitted through the dichroic mirror 71, and is irradiated onto the surface of the wafer W through the objective lens 72.
In this illumination optical system, the aperture stop 65 is provided on the conjugate plane of the pupil of the objective lens 72, and the field stop 67 is provided on the conjugate plane of the wafer W surface, so that only a predetermined field of view and a predetermined field of view are provided. Illumination light is emitted.

Reflected by the overlay mark on the surface of the wafer W,
The reflected light diffracted and scattered is along the measurement optical axis L, the objective lens 72, the dichroic mirror 71 and the half mirror 6.
After passing through 9, the light is guided to the imaging optical system, and is imaged on the imaging surface of the two-dimensional imaging device 74 by the imaging lens 73. The image signal of the overlay mark, which is photoelectrically converted by the image pickup device 74, is input to the image processing device 75, and is arithmetically processed by this device to obtain the overlay state of the overlay mark. For example, in a so-called box-in-box type overlay mark, an image of a first mark formed on a lower pattern layer and an image of a second mark formed on an upper pattern layer are used to form two images in the x-axis direction. , Y-axis positional deviation, θ-axis angular deviation, and the like.

Next, how the control device 5 controls the operation of the drive device 1 in the overlay measuring machine configured as described above will be described with reference to FIG. 3 and FIG. 4 together. . As described above, in order to specify the position on the surface of the wafer W, the center of the wafer Wo
And an xy coordinate system based on the position of the notch N are defined, and each chip area 101, 102, ..., 1 mn is defined.
And the position of the overlay mark formed in the chip area are specified as the coordinate value P1mn (x, y) on the xy coordinates.

The position of the overlay mark in each chip area thus specified is set and stored as the wafer data of the wafer to be inspected in the controller 5. In addition,
In the drawings, for convenience of description, the overlay mark in each chip area is shown as a black dot in the center of the chip area.

At the time of loading the wafer W, the controller 5
Outputs a command signal to the X-axis drive mechanism 10, the Y-axis drive mechanism 20, the Z-axis drive mechanism 30, and the θ-axis drive mechanism 40 to drive the X-axis stage 11, the Y-axis stage 21, and the Z-axis stage 31, respectively. Position it at the reference position when loading the axis,
The table 41 is positioned at the reference turning angle position θo = 0 °.

After the positioning of each axis drive mechanism is completed, the wafer W
When the preparation for loading is completed, the wafer W is loaded on the table 41 by a pre-alignment mechanism (not shown). At this time, in the pre-alignment mechanism, the center of the wafer W coincides with the center of rotation of the table 41 (center of the θ axis), and the xy axis of the wafer W becomes the XY axis of the XY axis stage of the drive mechanism 1. The wafer W is placed on the table 41 so as to match. The controller 5 operates the holding structure of the table 41 to suck and hold the wafer W on the table 41.

Next, the control device 5 outputs a command signal to the θ-axis drive mechanism 40 to rotate the table 41 by 45 degrees. As a result, the wafer W is horizontally swung by 45 degrees about the center Wo, and the xy of the wafer W with respect to the XY coordinates of the XY stage including the X-axis drive mechanism 10 and the Y-axis drive mechanism 20. Table 41 with the coordinates tilted 45 degrees
It is held on top (see the coordinate axes attached in FIG. 3).

Based on the wafer data set and stored in advance, the control device 5 holds X-of the overlay mark in each chip area on the wafer W surface when the wafer is held at a tilt of 45 degrees in the horizontal plane as described above. The position on the Y coordinate axis is calculated to obtain (P1mn (x, y) → P1mn (X, Y)), and the obtained position coordinate P1mn (X,
Based on Y), the operation of the X-axis drive mechanism 10 and the Y-axis drive mechanism 20 is controlled so as to move the overlay marks in each chip area in order.

Similar to the case of FIG. 6, let us consider a case where the measurement is performed in the order 168, 125, and 134 from the chip region 101. The overlay mark of each chip area is the measurement optical system 50.
X-axis drive mechanism 10 and Y
The shaft drive mechanism 20 is simultaneously operated to move and position the table 41.

The relative movement state of the table 41 with respect to the observation visual field position of the measurement optical system 50 at this time is as shown in FIG. 4 when moving from the chip area 101 to 168, for example, and the movement vector Dp of the table is , X stage movement vector Dx and Y due to movement of X stage 11
Movement vector Dy in the Y-axis direction due to movement of the stage 21
It is represented by a synthetic vector Dp = Dx + Dy.

Therefore, the amount of movement of the table 41 relative to the observation visual field position of the measuring optical system 50 is the magnitude of the movement vector | Dp |, but the amount of movement of the X stage 11 | Dx | and Y What is the amount of movement | Dy | of the stage 21?
The relationship is a right-angled isosceles triangle with Dp | as the hypotenuse, and X
The amount of movement of the stage 11 and the Y stage 21 is | Dx |
= | Dy | = (| Dp | / √2).

Since the controller 5 causes the X stage 11 to move in the X axis direction and the Y stage 21 to move in the Y axis direction at the same time, the observation visual field position of the measurement optical system 50 is moved from the chip area 101 to 168. As shown in FIG. 6, the time required for the table 41 to move is x− of the wafer W.
This can be shortened to 1 / √2 as compared with the case where the y-axis and the X-Y axis of the driving device 1 are aligned and moved in the Y-axis direction. In addition, in FIG.
Compared with the case of moving from 1 to 168, the moving amount is also 1 /
√2. Therefore, the dimensions of the device in the X-axis direction and the Y-axis direction can be shortened, and the device can be downsized.

The miniaturization of this device will be described in more detail. FIG. 5 is a diagram for explaining the movement range of the observation visual field position in the X-axis direction and the Y-axis direction in the present embodiment. FIG. 5A is a top view of a state in which the wafer W is held on the stage 41 by inclining the x axis and the y axis by 45 degrees with respect to the X axis and the Y axis. At this time, consider a quadrangle C that connects the intersections (there are four) of the x-axis and the y-axis and the outer periphery of the wafer W. If the observation visual field position can be moved within this quadrangle, overlay measurement in the chip areas 101, 168, 125, and 134 is possible. At this time, in the X-axis direction,
The moving range in the Y-axis direction may be 1 / √2 of the diameter of the wafer W.

FIG. 5B shows x with respect to the X axis and the Y axis.
The wafer W is moved to the stage 4 by inclining the axis and the y axis by 30 degrees.
It is the figure which looked at the state hold | maintained at 1 from the top. Figure 5 (a)
Similarly, considering a quadrangle C connecting the intersections (there are four) of the x-axis, y-axis and the outer periphery of the wafer W, if the observation visual field position is movable within this quadrangle, the chip area 1
Overlay measurements at 01, 168, 125 and 134 are possible. At this time, the movement range in the X-axis direction and the Y-axis direction is √3 / 2 of the diameter of the wafer W, which is longer than in the case of FIG. When the x-axis and the y-axis are inclined by 45 degrees with respect to the X-axis and the Y-axis as shown in FIG. 5A, the movement range in the X-axis direction and the Y-axis direction can be minimized.

Here, when the x-axis and y-axis and the outer circumference of the wafer W are on the notch or orientation flat, it is assumed that there is no notch or orientation flat and it is assumed that the outer circumference is an extension of the other outer peripheral portion. It is preferable to assume the quadrangle C based on the intersection of

In this way, when the X-axis drive mechanism 10 and the Y-axis drive mechanism 20 position the overlay mark in the chip area within the observation field of view of the measurement optical system 50, the controller 5 causes the AF processor to operate. A command signal is output to 95 and the image processing device 75 to start the overlay mark measurement process.

At this time, the wafer W is removed from the AF processing device 95.
When a correction signal for the surface height position is input,
The Z-axis drive mechanism 30 is operated according to the signal value to bring the overlay mark into the in-focus state, and the image of the in-focus overlay mark is taken into the image processing device 75 to measure the overlay state. To do. The measuring optical system 50 is mounted on the measuring optical system mounting frame with the same angle (45 degrees) as the tilt angle of the coordinate axis of the wafer W on the measuring optical system mounting frame, and the image processing device 75 has overlay marks on the xy axes. It is observed as an upright image in the direction. The image processing device 75 calculates and calculates the positional deviation and the angular deviation in the xy axis direction from the overlay mark of this erect image, and outputs the obtained overlay state to the control device 5.

When the measurement data is input from the image processing device 75, the control device 5 stores the measurement data in the internal memory as the first data of the chip area and outputs a command signal to the drive device 1, The X-axis drive mechanism 10 and the Y-axis drive mechanism 20 are simultaneously operated so that the next chip area to be measured is on the measurement optical axis L.

The control device 5 thereafter similarly performs the table 4
The moving positioning of 1 and the overlay measurement are sequentially repeated. Further, the overlay mark of the same chip area is measured again in a state where the table 41 is turned by 180 degrees and is stored in the internal memory as the second data of each chip area.

The control device 5 averages the first data and the second data stored in this way by arithmetic processing, and is a TIS (Tool Induced Shift) error which is an error in a measurement value due to the device that cannot be driven in when adjusting the device. ) Is corrected. Then, the positions of the lower pattern layer of the wafer W and the upper pattern layer at the time of exposure are determined from the corrected overlay state of each chip area (deviation amount and deviation angle in the x-axis direction and y-axis direction, deviation thereof). Find the deviation and angle deviation. The overlapping state thus obtained is output and displayed on a display device (not shown) such as a CRT screen. At this time, as in the present embodiment, even if the overlay state is not measured for all the chip areas, the result of the measured chip area is used to overlay the non-measured chip areas. The state can be estimated. This estimation can be performed by the arithmetic processing by the control device 5, and the result can be output and displayed.

The operator who operates the overlay measuring machine is C
From the image information displayed on the RT screen, it is possible to detect the misalignment state of each chip and its distribution, the misalignment state of the entire wafer W surface, and perform appropriate feedback.

In the present embodiment, when the wafer W is loaded on the table 41, the pre-alignment mechanism causes the table 41 to move so that the xy axis of the wafer W and the XY axis of the drive unit coincide with each other. It was placed, and the table was rotated by a predetermined angle by the θ-axis drive mechanism 40 and held. However, the wafer W may be tilted by a predetermined angle to be loaded on the table and held on the table 41 at the predetermined angle.

As described above, the array direction (xy axis direction) of the chip regions repeated on the wafer W surface is inclined at a predetermined angle with respect to the XY axes of the X axis drive mechanism 10 and the Y axis drive mechanism 20. As described above, according to the drive device 1 that holds the wafer W on the table 41 and the controller 5 moves and positions the table in the tilt direction, the movement vector of the table is set to the movement vector in the X-axis direction and the movement vector in the Y-axis direction. It can be decomposed into a movement vector, and the movement time can be shortened by simultaneously operating both the X-Y axis direction drive mechanisms thus decomposed.

As described above, the effect of the vector decomposition of the movement directions and the simultaneous operation is that the measurement optical system is moved relative to the base even when the table is moved on the XY coordinate plane. The same applies when moving the system on the XY coordinate plane, and when moving the table in one axial direction of the XY axes and moving the measurement optical system in another axial direction. Is also the same.

Therefore, by constructing the driving device as described above and operating it according to the control method described above, it is possible to shorten the moving and positioning time of the semiconductor wafer substrate, the liquid crystal substrate or the like having a regularity in a certain direction, or to perform the exposure optical system. It is possible to provide various manufacturing apparatuses and inspection apparatuses capable of achieving high throughput by shortening the movement positioning time of the system and the measurement optical system.

The arrangement direction of the drive shaft in the drive mechanism for moving the table and the optical system in two directions (XY axis directions) orthogonal to each other in the horizontal plane is the front-rear-left and right-hand sides of the apparatus main body of the manufacturing apparatus or the inspection apparatus. Although it is generally arranged along the direction, in the present embodiment, the arrangement direction of the drive shaft is arranged so as to be inclined by about 30 to 60 degrees with respect to the front-back and left-right directions of the apparatus main body. Is preferred.

For example, if the table holding the wafer W is X
In the drive mechanism 1 that moves in the −Y axis direction, the X stage 1
X-axis drive structure for moving 1 (ball screw 13,
Servo motor 15 and the like) are arranged on the X-axis, and a Y-axis drive structure (ball screw 2) for moving the Y stage 21 is arranged.
3, the servomotor 25, etc.) are arranged on the Y axis. The axial length of the drive structure for each of these axes is naturally larger than the movement stroke of the X stage 11 and the Y stage 21. For this reason, for example, in the drive device 1, the servo motor 15 of the X-axis drive structure and the bearing case supporting the ball screw 13 at the other end side project from the base B in the X-axis direction, and the servo motor 25 of the Y-axis drive mechanism and others. The bearing case that supports the ball screw 23 at the end side is the X stage 11
To project in the Y-axis direction.

When the X-axis and the Y-axis are overlapped and arranged in the front-rear and left-right directions of the measuring machine, the projection amounts in the X-axis direction and the Y-axis direction are the same as those of the measuring machine. Will lead to an increase in dimensions.

However, when the X-Y axes are arranged so as to be inclined with respect to the main body of the measuring machine, the amount of protrusion in the front, rear, left and right directions can be reduced according to the inclination angle. For example, when the X-Y axis is inclined by 45 degrees, the amount of protrusion in the front-rear direction and the left-right direction can be reduced to 1 / √2. Therefore, according to the manufacturing apparatus and the inspection apparatus in which the X-Y axes are inclined as described above, it is possible to reduce the front-rear and left-right dimension of the apparatus, and to provide the space-saving manufacturing apparatus and the inspection apparatus. You can

The inclination angle with respect to the machine body when the XY axes are inclined and arranged is as follows:
It is possible to set an appropriate angle according to the arrangement positions of the axes and the Y-axis, the protrusion amounts of the servo motors for both the X and Y axes, and the like.

[0062]

As described above, according to the present invention, the positional relationship between the table holding the substrate and the observation field of view of the optical system for observing a part of the substrate held on the table is orthogonal to the first. In a substrate inspection device that moves relative to the axis in a second axial direction, a third unit that is orthogonal to a predetermined position on the substrate as a reference.
Of the third axis and the fourth axis are held on the table in a state in which the direction of the coordinate axis for indicating the position on the substrate is inclined with respect to the directions of the first axis and the second axis. The board inspecting device is configured to be movable based on the axis and the fourth axis. Therefore, the amount of movement between the first axis and the second axis of the drive device can be reduced according to the tilt angle of the coordinate axes, which suppresses an increase in size of the device and provides a small substrate inspection device. can do.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an overlay measurement apparatus as an example of a board inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an optical system of an overlay measuring apparatus as an example of the board inspection apparatus according to the embodiment of the present invention.

FIG. 3 is a view showing an XY in a driving device of an overlay measuring apparatus as an example of a substrate inspecting apparatus according to an embodiment of the present invention.
It is a figure which shows the relationship between an axis | shaft and the xy axis | shaft of the wafer hold | maintained on the table by inclining.

FIG. 4 is a diagram showing a relationship between a movement vector of an observation visual field position and a movement vector decomposed in the X-Y axis directions of the driving device in the embodiment of the present invention.

FIG. 5 is a diagram showing an X of an observation visual field position in the embodiment of the present invention.
It is a figure for demonstrating the moving range of an axial direction and a Y-axis direction.

FIG. 6 is a diagram showing a conventional relationship between an XY axis of a driving device and an xy axis of a wafer.

[Explanation of symbols]

B base W semiconductor wafer 1 drive 5 control device 10 X-axis drive mechanism 20 Y-axis drive mechanism 30 Z-axis drive mechanism 40 θ-axis drive mechanism 41 table 50 Measuring optical system 75 Image processing device

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G014 AA32 AB59 AC12                 4M106 AA01 CA39 DJ04                 5F031 CA02 CA13 JA02 JA28 JA38                       KA06 KA08 MA33 PA30                 5F046 EB01 EB05 FA10 FA17 FC03                       FC04

Claims (3)

[Claims] 1. A table holding a substrate, an optical system having a part of the substrate as an observation field of view, and a positional relationship between the table and the observation field of view of the optical system are orthogonal to a first axis and a second axis. And a drive means for relatively moving in the axial direction of the substrate, for indicating a position on the substrate, which is composed of a third axis and a fourth axis orthogonal to each other with respect to a predetermined position on the substrate. The direction of the coordinate axis and the directions of the first axis and the second axis are
The substrate is held on the table in a tilted state,
Further, the inspection visual field can be moved by the drive means only within a quadrangle connecting four points where the third axis and the fourth axis intersect the outer circumference of the substrate. apparatus. 2. A table for holding a substrate, an optical system for observing a part of the substrate as an observation field of view, and a positional relationship between the table and the observation field of view of the optical system are orthogonal to a first axis and a second axis. And a drive means for relatively moving in the axial direction of the substrate, for indicating a position on the substrate, which is composed of a third axis and a fourth axis orthogonal to each other with respect to a predetermined position on the substrate. The direction of the coordinate axis and the directions of the first axis and the second axis are
The substrate is held on the table in a tilted state,
Further, the substrate inspection apparatus is characterized in that the relative movement ranges of the first axis and the second axis are shorter than the diameter of the substrate. 3. The substrate inspection apparatus according to claim 1, further comprising an image capturing unit that captures an image formed by the optical system as an image, and the drive unit includes an inspected surface of the substrate. A mark indicating a superposition state of a plurality of pattern layers provided on the optical system is positioned within an observation visual field of the optical system, the image capturing means captures an image of the mark as an image, and the superposition is performed based on the image. A board inspection device characterized by detecting a state.