JP2003133224A - Method and device for setting surface position and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the surface position of a substrate highly accurately at a high speed during scanning. SOLUTION: The surface position is continuously detected in a surface position detection system 26 while scanning the surface position of a wafer 4, i.e., a substrate, sucked and fixed onto a stage 5 moving in X and Y directions and the height direction relatively. The surface position detection system 26 utilizes a light receiving lens 16 or a photoelectric conversion means group 19 for photoelectrically converts reflection light from a light source 10 on the projecting part side projecting surface position detection light to the surface of the wafer 4 or a slit member 12 or the like and the wafer 4 by means of a photoelectric conversion element, on the light receiving part side and finding a substrate surface position, uses a plurality of one-dimensional imaging elements inputting a shift pulse giving a drive pulse of each pixel and a reset pulse determining an accumulation section of the imaging element as the photoelectric conversion element, and gives reset pulses of different phases for at least one imaging element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface position setting method, a surface position setting device, an exposure device and the like for detecting and setting the height and surface position, and more particularly, in a slit scan type exposure device, the light of a projection optical system is used. It is suitable for a surface position setting method and a surface position setting device for continuously detecting and setting the position and inclination of the wafer surface in the axial direction.

[0002]

2. Description of the Related Art Recently, the size of a memory chip shows a gradual expansion tendency from the difference between the trend of the resolution line width of an exposure apparatus and the trend of the expansion of the memory capacity with respect to the trend of the cell size. In the first generation of, it is reported to be about 14 × 25 mm.

With this chip size, a reduction projection exposure apparatus (stepper) currently used as an exposure apparatus for a critical layer has an exposure area of 31 mm in diameter, and only one chip can be exposed per exposure, and throughput cannot be increased. Therefore, there is a need for an exposure apparatus that enables a larger exposure area. As a large screen exposure apparatus, a reflection projection exposure apparatus has been widely used as a semiconductor device exposure apparatus for a rough layer, which is required to have a high throughput, or an exposure apparatus for a large screen liquid crystal display device such as a monitor. This is a so-called mask-wafer relative scanning slit-scan type exposure apparatus that linearly scans a mask with illumination light in the shape of an arc slit and exposes the mask collectively on a wafer by a concentric reflection mirror optical system.

Focusing of the mask image in these devices is performed by adjusting the height of the exposure surface of the photosensitive substrate (wafer or glass plate coated with photoresist or the like) to the best image plane of the projection optical system. Measurement and correction drive of auto focus and auto leveling are continuously performed during scan exposure.

The height and surface position detection mechanism in these devices uses, for example, a so-called oblique incidence optical system in which a light beam is obliquely incident on the wafer surface, so that the reflected light from the photosensitive substrate is displaced on the CCD or PSD sensor. There is a method for detecting the height and inclination when the measurement position passes through the exposure slit area from a plurality of height measurement values during scanning, and the correction drive amount is calculated and corrected.

A conventional slit scan type projection exposure apparatus will be specifically described with reference to FIG. In FIG. 1, reference numeral 1 denotes a reduction projection lens, the optical axis of which is indicated by AX in the drawing, and its image plane is in a relationship perpendicular to the Z direction in the drawing. The reticle 2 is held on the reticle stage 3, and the pattern of the reticle 2 is reduced and projected to 1/4 to 1/2 at the magnification of the reduction projection lens to form an image on its image plane.
Reference numeral 4 denotes a wafer having a surface coated with a resist, in which a large number of exposed regions (shots) formed in the previous exposure process are arranged. Reference numeral 5 denotes a stage on which the wafer 4 is placed, a chuck for adsorbing and fixing the wafer 4 on the wafer stage 5, and an X movable horizontally in the X-axis direction and the Y-axis direction, respectively.
A Y stage, a leveling stage that is movable in the Z axis direction, which is the optical axis direction of the projection lens 1, and rotatable about a horizontal axis along the X axis and Y axis directions, and an axis that is horizontal to the Z axis. And a rotary stage rotatable around the axis of the reticle, and constitutes a 6-axis correction system for matching the reticle pattern image with the exposed region on the wafer 4.

Reference numerals 10 to 19 in FIG. 1 denote respective elements of a detection optical system provided for detecting the surface position and the inclination of the wafer 4. Although only two light fluxes are shown in FIG. 1, each light flux has three light fluxes in the direction perpendicular to the paper surface. At this time, the plane in which the pinhole is formed with respect to the lens system 13 and the plane including the surface of the wafer 4 are set so as to satisfy the Scheimpflug condition.

Reference numerals 15 to 19 in FIG. 1 denote detection optical systems for detecting the reflected light beam from the wafer 4 next. Further, on the light receiving side (16 to 18), tilt correction is performed so that each measurement point on the surface of the wafer 4 and the detection surface of the photoelectric conversion means group 19 are conjugated with each other.
The position of the pinhole image on the detection surface does not change due to the local inclination of each measurement point, and the pinhole image on the detection surface responds to the height change of each measurement point in the optical axis AX direction. Are configured to change.

The photoelectric conversion means group 19 includes six one-dimensional CCs.
It is composed of a D line sensor. Figure 2 is a CCD
It is a figure showing the relation between the drive clock of a line sensor and the control cycle of a stage control system. A measurement command is issued to the autofocus measurement system at the stage position 1. Upon receiving this, the auto-focus measurement system is the next CCD accumulation section 30.
Image accumulation starts from. When the image storage is completed, in the section 33, the charge is transferred to the shift register of the CCD by the reset pulse, and the stored charge amount is converted into a voltage for each position pixel and output. In the section 34, the focus measurement system calculates the Z-direction position and the wafer surface based on this data and returns the result to the stage control system. The wafer position returned to the stage control system in this case is an average value of the stage positions 4 to 7 accumulated in the section 30. Next, the stage control system issues a measurement command to the autofocus measurement system when the stage position is 17. In response to this, the auto-focus measurement system detects the stage positions 20 to 2 accumulated in the section 32.
The average value during 3 is returned to the stage control system. This allows
Accurate surface position measurement is possible according to the wafer position,
Since the wafer stage has become faster with the recent increase in throughput of semiconductor exposure apparatuses, surface measurement is required to be performed in a shorter time.

[0010]

However, under the present circumstances, the measurement interval cannot be increased because of being restricted by the pixel accumulation time and the pixel reading time. The pixel accumulation time is defined by the amount of light applied to the wafer surface, and cannot be shortened unnecessarily in order to reduce the influence of air fluctuations in the measurement optical path. Further, the pixel read clock cannot be uniquely raised because it is determined by the pixel clock of the image sensor.

It is an object of the present invention to provide a surface position setting method, a surface position setting device and an exposure device which can set the surface position of a substrate during scanning with high accuracy and high speed.

[0012]

In order to achieve the above-mentioned object, the present invention provides a method for performing relative scanning of the surface position of a substrate suction-fixed on a stage that moves at least in the X, Y and height directions. In a surface position setting method in which a position detection system continuously detects and drives, the surface position detection system includes a light projecting unit that projects surface position detection light onto the substrate surface and a photoelectric conversion element that reflects light from the substrate. At least two pulse trains of a shift pulse for giving a drive pulse of each pixel as the photoelectric conversion element and a reset pulse for determining an accumulation section of the image pickup element are input by using a light receiving section for photoelectrically converting the substrate surface position. It is characterized in that a plurality of one-dimensional or two-dimensional image pickup devices are used and reset pulses having different phases are applied to at least one of the image pickup devices. As a result, the present invention enables high-speed and highly accurate surface position setting.

Further, according to the present invention, the surface which is continuously detected and driven by the surface position detecting system while relatively scanning the surface position of the substrate suction-fixed on the stage which moves in at least the X and Y directions and the height direction. In the position setting method, the surface position detection system includes a light projecting unit that projects surface position detection light onto the substrate surface and a light receiving unit that photoelectrically converts reflected light from the substrate by a photoelectric conversion element to obtain the substrate surface position. And a plurality of one-dimensional and two-dimensional imaging for inputting at least two pulse trains of a shift pulse for applying a drive pulse of each pixel as the photoelectric conversion element and a reset pulse for determining an accumulation section of the image sensor The device is characterized in that the height of the substrate is detected by data from the plurality of image pickup devices arranged in different pixel scan directions of the image pickup device. It may be. Also by this, the present invention enables high-speed and highly accurate surface position setting.

In the present invention, a surface position setting device using any one of the surface position setting methods described above is used, or a part of the pattern of the original plate is projected onto the substrate through a projection optical system while relatively scanning the original plate and the substrate. A scanning type exposure apparatus for projecting and exposing, which is characterized by including the surface position setting apparatus, enables high-speed and highly-accurate substrate height setting.

Further, the present invention includes the steps of installing a manufacturing apparatus group for various processes including the exposure apparatus in a semiconductor manufacturing factory, and a step of manufacturing a semiconductor device by a plurality of processes using the manufacturing apparatus group. The present invention is also applied to a semiconductor device manufacturing method having the same. The method further includes the steps of connecting the manufacturing apparatus group with a local area network, and performing data communication between the local area network and an external network outside the semiconductor manufacturing factory for information regarding at least one of the manufacturing apparatus group. It is desirable to have a database provided by a vendor or a user of the exposure apparatus via the external network to obtain maintenance information of the manufacturing apparatus by data communication, or a semiconductor manufacturing factory different from the semiconductor manufacturing factory. It is preferable that data is communicated with the product via the external network for production management.

Further, according to the present invention, manufacturing apparatus groups for various processes including the exposure apparatus, a local area network connecting the manufacturing apparatus groups, and an external network outside the factory can be accessed from the local area network. The present invention is also applied to a semiconductor manufacturing factory having a gateway and capable of performing data communication of information regarding at least one of the manufacturing apparatus group.

The present invention also provides a maintenance method of the exposure apparatus installed in a semiconductor manufacturing factory, wherein a vendor or a user of the exposure apparatus provides a maintenance database connected to an external network of the semiconductor manufacturing factory. A step of permitting access to the maintenance database from the semiconductor manufacturing factory via the external network, and transmitting maintenance information accumulated in the maintenance database to the semiconductor manufacturing factory side via the external network. It may be characterized by having a process.

The present invention also provides the above-mentioned exposure apparatus,
It may be characterized in that it further includes a display, a network interface, and a computer that executes software for the network, and allows maintenance information of the exposure apparatus to be data-communicated via a computer network. The network software is
A user interface for accessing a maintenance database provided by a vendor or a user of the exposure apparatus, which is connected to an external network of a factory in which the exposure apparatus is installed, is provided on the display, and from the database via the external network. It is preferable to be able to obtain information.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment of Surface Position Setting Method, Surface Position Setting Device and Exposure Device) FIG. 1 shows the essentials of a slit scan type projection exposure apparatus equipped with a surface position detection device according to an embodiment of the present invention. It is the schematic which shows a part. In FIG. 1, reference numeral 1 denotes a reduction projection lens whose optical axis is AX in the figure.
, And its image plane is perpendicular to the Z direction in the figure. The reticle 2 as an original plate is held on the reticle stage 3, and the pattern of the reticle 2 is reduced and projected to 1/4 to 1/2 by the magnification of the reduction projection lens to form an image on its image plane. Reference numeral 4 denotes a wafer as a substrate whose surface is coated with a resist, in which a large number of exposed regions (shots) formed in the previous exposure step are arranged. Reference numeral 5 denotes a wafer stage on which the wafer 4 is placed, a chuck for adsorbing and fixing the wafer 4 on the wafer stage 5, an XY stage horizontally movable in the X-axis direction and the Y-axis direction, and a projection lens 1.
In the Z-axis direction, which is the optical axis direction, and a leveling stage rotatable about a horizontal axis along the X-axis direction and the Y-axis direction, and a rotation rotatable about an axis horizontal to the Z-axis. The stage comprises a 6-axis correction system for matching the reticle pattern image with the exposed region on the wafer 4.

Reference numeral 10 to 19 in FIG. 1 designates the wafer 4.
It shows each element of the detection optical system provided for detecting the surface position and inclination of the. Reference numeral 10 denotes a light source, which includes a white lamp or an illumination unit configured to emit light from a high-intensity light emitting diode having a plurality of different peak wavelengths. Reference numeral 11 denotes a collimator lens, which emits the light flux from the light source 10 as a parallel light flux whose cross-sectional intensity distribution is substantially uniform. Reference numeral 12 is a prism-shaped slit member, and a pair of prisms are attached to each other so that their slopes face each other. A plurality of openings (for example, 6 pinholes) are formed in the attachment surface, and a light-shielding film such as chrome is used. Is provided. 13 is a lens system, and this lens system 1
3 is a double telecentric system and has a slit member 1
Six independent light fluxes that have passed through the plurality of two pinholes are guided to six measurement points on the surface of the wafer 4 via the bending mirror 14. In FIG. 1, only two light fluxes are shown, but each light flux has three light fluxes in the direction perpendicular to the paper surface. At this time, the plane on which the pinhole is formed and the plane including the surface of the wafer 4 are set so as to satisfy the Scheimpflug condition with respect to the lens system 13.

In the present embodiment, the incident angle Φ of each light beam from the light irradiation means on the surface of the wafer 4 (perpendicular to the wafer surface, that is, the angle with the optical axis AX) is Φ = 70 ° or more.
On the surface of the wafer 4, as shown in FIG. 15, a plurality of pattern regions (exposure region shots) are arranged. The six light fluxes that have passed through the lens system 13 are as shown in FIG.
The light is incident and imaged on each measurement point independent of each other in the pattern area. Further, in order that the six measurement points are observed independently of each other in the plane of the wafer 4, the light is made incident from the direction rotated by Θ ° (for example, 22.5 °) in the XY plane from the X direction (scan direction). ing.

As a result, according to the invention of Japanese Patent Application No. 3-157822 (Japanese Patent Laid-Open No. 4-354320),
The spatial arrangement of each element is optimized to facilitate highly accurate detection of surface position information.

Next, the side that detects the reflected light beam from the wafer 4, that is, the elements associated with reference numerals 15 to 19 will be described. Reference numeral 16 denotes a light receiving lens, which is composed of both telecentric systems and receives the six reflected light beams from the surface of the wafer 4 via the bending mirror 15. The stopper diaphragm 17 provided in the light-receiving lens 16 is commonly provided for each of the six measurement points, and cuts off higher-order diffracted light (noise light) generated by the circuit pattern existing on the wafer 4. . The light beams passing through the light receiving lens 16 composed of both telecentric systems have their optical axes parallel to each other, and are incident on the detection surface of the photoelectric conversion means group 19 by the six individual correction lenses of the correction optical system group 18. The images are re-imaged so that the spot lights have the same size. Also,
On the light receiving side (16 to 18), tilt correction is performed so that each measurement point on the surface of the wafer 4 and the detection surface of the photoelectric conversion means group 19 are conjugate with each other, and therefore The position of the pinhole image on the detection surface does not change due to the local inclination, and the pinhole image changes on the detection surface in response to the height change of each measurement point in the optical axis AX direction. It is configured.

The photoelectric conversion means group 19 is composed of six one-dimensional CCD line sensors. This is advantageous over the configuration of the conventional two-dimensional sensor in the following points. First, by separating the photoelectric conversion means in forming the correction optical system group 18, the degree of freedom in arranging each optical member and mechanical holder is increased. Further, in order to improve the resolution of the detection, it is necessary to increase the optical magnification from the bending mirror 15 to the correction optical system group 18, but also in this point, the optical path is divided and made incident on individual sensors. But,
It is possible to compact the members. Furthermore, in the slit scan method, continuous focus measurement during exposure is indispensable, and shortening the measurement time is an absolute issue. One reason is that conventional 2D CCD sensors read more data than necessary. Yes, the read time is 10 times or more that of the one-dimensional CCD sensor.

Next, a slit scan type exposure system will be described. As shown in FIG. 1, the reticle 2
Is sucked and fixed on the reticle stage 3, then scanned at a constant speed in the RX direction (X-axis direction) shown in FIG. 1 in a plane perpendicular to the optical axis AX of the projection lens 1, and
In the direction (Y-axis direction: vertical to the paper surface), correction driving is performed so that the target coordinate position is always scanned. The position information of the reticle stage 3 in the X and Y directions is obtained by irradiating the XY bar mirror 20 fixed to the reticle stage 3 in FIG. 1 with a plurality of laser beams from the outside by a reticle stage interferometer (XY) 21. It is always measured by Similarly, the X-direction and Y-direction of the wafer stage 5
The positional information of the directions is XY fixed on the wafer stage 5.
Wafer stage interferometer (XY) 24 to bar mirror 23
By irradiating multiple laser beams by
Always available.

The exposure illumination optical system 6 uses a light source for generating pulsed light such as an excimer laser, and is composed of members such as a beam shaping optical system (not shown), an optical integrator, a collimator, and a mirror. It is made of a material that efficiently transmits or reflects light. The beam shaping optical system is for shaping the cross-sectional shape (including dimensions) of the incident beam into a desired shape, and the optical integrator makes the light distribution characteristics of the light flux uniform and illuminates the reticle 2 with uniform illuminance. belongs to. A rectangular illumination area corresponding to the chip size is set by a masking blade (not shown) in the exposure illumination optical system 6, and the pattern on the reticle 2 partially illuminated by the illumination area is transferred via the projection lens 1 to the resist. It is projected onto the coated wafer 4.

The main controller 27 shown in FIG. 1 rotates the slit image of the reticle 2 on a predetermined area of the wafer 4 at a position in the XY plane (X, Y positions, and rotation about an axis parallel to the Z axis). ) And the position in the Z direction (rotations α, β around the axes parallel to the X and Y axes, and the height Z on the Z axis) are controlled so that the scan exposure is performed. That is, for the alignment of the reticle pattern in the XY plane, control data is calculated from the position data of the reticle stage interferometer 21, the wafer stage interferometer 24, and the position data of the wafer 4 obtained from an alignment microscope (not shown). , Reticle position control system 22 and wafer position control system 25.

When the reticle stage 3 is scanned in the direction of arrow 3a in FIG. 1, the wafer stage 5 is scanned in the direction of arrow 5a in FIG. 1 at a speed corrected by the reduction magnification of the projection lens. The scan speed of the reticle stage 3 is determined so that the throughput is advantageous based on the width of the masking blade (not shown) in the scanning direction in the exposure illumination optical system 6 and the sensitivity of the resist coated on the surface of the wafer 4.

The alignment of the reticle pattern in the Z-axis direction, that is, alignment with the image plane is performed via the wafer position control system 25 based on the calculation result of the surface position detection system 26 which detects the height data of the wafer 4. Control is performed on the leveling stage in the wafer stage 5. That is, the correction to the optimum image plane position at the exposure position is performed by the wafer height measuring spot light 3 arranged near the slit in the scanning direction.
The inclination in the scan direction and the vertical direction and the height in the optical axis AX direction are calculated from the height data of the points, and the correction amount is obtained.

A method of detecting the height position of the exposed region of the wafer 4 by the surface position detecting method of the present invention will be described below. FIG. 3 shows the relationship between the wafer height measurement position and the position of the exposure area during wafer exposure. The reticle pattern is exposed on the moving wafer surface 41, and the wafer surface 4 is exposed.
It is assumed that 1 is moving in the direction of ← at a speed v. In FIG. 3, the height measuring means 40B is provided at a position away from the exposure region by a distance d in the traveling direction of the wafer, and when the point A on the wafer is below the height measuring means 40B, The height of the wafer surface is measured, and when the point A comes to the center of the exposure area C, the wafer height is driven to the exposure surface. In this case, the wafer height measurement sampling interval t need only be shorter than the time required for the wafer to move by the distance d, and is represented by the following equation. t ≦ d / v

When changing the height of the wafer surface during exposure,
The following three can be considered. First, for changes in height inside the chip, then for changes in the seam (scribe line) of the chip, and finally for changes when the exposure area enters the wafer from outside the wafer. Is.
Fluctuations within the chip are caused by chemical mechanical planarization CMP (Chemical Mechanical Plai) for the cell part and the peripheral circuit part.
n)), etc.
Although the step is about m, and the step between the chip and the scribe is larger than the step in the chip, it is still several μ
While the height is about m, the wafer surface is first fixed at an appropriate height when the wafer outer peripheral portion is exposed, and the height is measured after the height measuring means enters the position where the height can be measured on the wafer. The height drive is performed until the exposure area moves onto the wafer. For this reason, in some cases, the wafer height must be changed by about 10 μm within the time required for the wafer to move the distance between the exposure area center and the wafer height measuring sensor.

Therefore, the response speed of the wafer height control system is not determined by considering only the step in the wafer, but the response of the wafer height control system when the wafer is driven from outside the wafer during exposure. Need to determine speed. Therefore, the response speed of the wafer height control system is fast enough to drive the height variation in the chip while the wafer moves from the center of the exposure area by the distance between the wafer height measuring sensors. ing.

FIG. 4 shows the wafer position control system 2 in FIG.
5 is a diagram showing a relationship among the control cycle of No. 5, the accumulation time of the detection system image sensor of the surface position detection system 26, the pixel transfer time, and the calculation time.

At the stage position 1 portion, a measurement command is issued from the wafer position control system 25 to the surface position detection system 26. Upon receiving this, the surface position detection system 26 starts image storage from the next CCD storage section 40. When the image accumulation is completed, section 41
At the reset pulse, the charge is transferred to the shift register of the CCD, and the accumulated charge amount is converted into a voltage for each position pixel and output. The surface position detection system 26 calculates the position in the Z direction and the wafer surface in the section 42 based on this data, and sends it back to the wafer position control system 25. The wafer position returned to the wafer position control system 25 in this case is an average value of the stage positions 4 to 7. Next, the wafer position control system 25 issues a measurement command to the surface position detection system 26 at the stage position 17. As a result, the surface position detection system 26
Returns the average value between the stage positions 19 to 22 to the wafer position control system 25. According to the above means, it is possible to accurately measure the surface position according to the position of the wafer. However, since the wafer stage speeds up with the recent increase in throughput of the semiconductor exposure apparatus, the surface measurement can be performed in a shorter time. Is required to be measured.

For this purpose, the present invention constitutes a surface position measuring system using a plurality of image pickup devices. This will be explained below.

FIG. 7A shows a part of the reflected light detecting system of the surface position measuring system. Reference numerals 60a and 60b denote image pickup devices, and each image pickup device is configured such that the position of the image of the pinhole formed on the image pickup device changes in accordance with the change in wafer height. The received light 62 is split into two by the beam splitter 61 and is incident on the image pickup devices 60a and 60b. The image pickup devices 60a and 60b are driven by inputting reset pulses whose phases are shifted. FIG. 5 is a timing chart of the wafer position control system and the surface position detection system in FIG. When the wafer position is 1, the surface position measurement command is issued to the surface position detection system 26. On the other hand, the average surface position between the stage positions 3 to 6 is calculated from the pixel data accumulated in the image sensor 60a. Next, when the wafer position 9 is reached, a surface position measurement command is issued.
According to the pixel data accumulated in b, the stage positions 11 to 11
An average surface position of 14 is calculated. After that, by repeating this, the surface position can be measured at an interval of 1/2 of that in the case of FIG. If there is a positional offset deviation or magnification deviation in the detection results between the image pickup elements, this is measured in advance and reflected at the time of measurement. In the present embodiment, the two image pickup devices generate the reset pulse and the image pickup device drive pulse from the control system reference clock. Therefore, the phase relationship between the wafer position control system control cycle and the reset pulse is always constant, and the wafer position control is performed. Since the measurement command output by the system and the imaging timing of the image sensor of the surface position measurement system are constant, it is possible to perform good surface position measurement with good measurement reproducibility.

FIG. 7B has the same configuration as that of FIG. 7A, but the image pickup device 60b is mounted upside down from that of FIG. 7A, so that the output direction of the pixel is the image pickup device. 60a and the image sensor 60b are different. This will be described with reference to FIG. FIG. 8A shows the image pickup devices 60a and 60b.
It is a pinhole image imaged on the top. In this example, six pinholes are formed. The image picked up by the image pickup device 60a outputs pixels in order from the left pinhole image as shown in FIG. 8B. On the other hand, the image sensor 60b
The image picked up in step (1) is output from the pinhole image on the right side as shown in FIG. FIG. 6 is an operation timing chart of the wafer position control system and the surface position detection system in FIG. 7B. When the wafer position is 1, a surface position measurement command is issued to the surface position detection system. On the other hand, the image sensor 60
The left half pinhole position in FIG. 8 is detected by the image data captured in a, and the right half pinhole position in FIG. 8 is detected by the image data captured by the image sensor 60b. After detecting both pinhole positions, send the other data to the other, calculate the overall surface position,
The result is returned to the wafer position control system. This allows
The average surface position between the stage positions 3 to 6 is calculated from the pixel data accumulated by the image sensor 60b. If the detection result between the image pickup devices 60a and 60b has a positional offset deviation or a magnification deviation, this is measured in advance and reflected at the time of measurement. By repeating this process, the surface position can be measured at an interval ½ that in the case of FIG.

(Embodiment of Semiconductor Production System) Next,
Semiconductor devices (ICs and LSs) using the apparatus according to the present invention
An example of a production system of a semiconductor chip such as I, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc. will be described. This is to perform maintenance services such as troubleshooting of a manufacturing apparatus installed in a semiconductor manufacturing factory, periodic maintenance, or software provision using a computer network outside the manufacturing factory.

FIG. 9 shows the whole system cut out from a certain angle. In the figure, 101 is a business office of a vendor (apparatus supplier) that provides a semiconductor device manufacturing apparatus. As an example of the manufacturing apparatus, a semiconductor manufacturing apparatus for various processes used in a semiconductor manufacturing factory, for example,
Pre-process equipment (lithography equipment such as exposure equipment, resist processing equipment, etching equipment, heat treatment equipment, film forming equipment,
Flattening equipment, etc.) and post-process equipment (assembling equipment, inspection equipment, etc.) are assumed. In the business office 101, a host management system 10 that provides a maintenance database for manufacturing equipment is provided.
8, a plurality of operation terminal computers 110, and a local area network (LAN) 109 that connects these to construct an intranet or the like. Host management system 1
08 is provided with a gateway for connecting the LAN 109 to the Internet 105, which is an external network of the office, and a security function for restricting access from the outside.

On the other hand, 102 to 104 are manufacturing factories of semiconductor manufacturers as users of manufacturing apparatuses. The manufacturing factories 102 to 104 may be factories belonging to different manufacturers or may be factories belonging to the same manufacturer (for example, a factory for pre-process, a factory for post-process, etc.). In each of the factories 102 to 104, a plurality of manufacturing apparatuses 106, a local area network (LAN) 111 that connects them to construct an intranet, and a host as a monitoring apparatus that monitors the operating status of each manufacturing apparatus 106 are provided. A management system 107 is provided. Each factory 1
02-104 host management system 107
Is provided with a gateway for connecting the LAN 111 in each factory to the Internet 105 which is an external network of the factory. As a result, it becomes possible to access the host management system 108 on the side of the business office 101 of the vendor from the LAN 111 of each factory via the Internet 105, and the security function of the host management system 108 allows access to only a limited number of users. . Specifically, each manufacturing apparatus 1 is connected via the Internet 105.
In addition to notifying status information indicating the operating status of 06 (for example, a symptom of a manufacturing apparatus in which a trouble has occurred) from the factory side to the vendor side, response information corresponding to the notification (for example, information instructing a troubleshooting method, You can receive maintenance information such as software (data and data for handling), the latest software, and help information from the vendor side. A communication protocol (TCP / IP) generally used on the Internet is used for data communication between each of the factories 102 to 104 and the vendor's office 101 and data communication via the LAN 111 in each factory. . In addition,
Instead of using the Internet as an external network outside the factory, it is possible to use a leased line network (ISDN or the like) having high security without being accessed by a third party. Further, the host management system is not limited to one provided by a vendor, and a user may construct a database and place it on an external network to permit access from a plurality of factories of the user to the database.

Now, FIG. 10 is a conceptual diagram showing the entire system of this embodiment cut out from an angle different from that shown in FIG. In the above example, a plurality of user factories each equipped with a manufacturing apparatus and a management system of a vendor of the manufacturing apparatus are connected by an external network, and production management of each factory or at least one unit is performed via the external network. The information of the manufacturing apparatus was data-communicated. On the other hand, in this example, a factory equipped with manufacturing equipment of a plurality of vendors and a management system of each vendor of the plurality of manufacturing equipments are connected by an external network outside the factory, and maintenance information of each manufacturing equipment is displayed. It is for data communication. In the figure, reference numeral 201 denotes a manufacturing plant of a manufacturing apparatus user (semiconductor device manufacturing maker), and a manufacturing apparatus for performing various processes is installed on a manufacturing line of the factory, here, as an example, an exposure apparatus 202, a resist processing apparatus 203,
The film forming processing device 204 is introduced. Although only one manufacturing factory 201 is shown in FIG. 10, a plurality of factories are actually networked in the same manner. The respective devices in the factory are connected by a LAN 206 to form an intranet, and the host management system 205 manages the operation of the manufacturing line.

On the other hand, the host management system 21 for remote maintenance of the supplied equipment is provided at each business office of the vendor (apparatus supply manufacturer) such as the exposure equipment manufacturer 210, the resist processing equipment manufacturer 220, and the film deposition equipment manufacturer 230.
1, 221, 231, which are provided with the maintenance database and the gateway of the external network as described above. A host management system 205 that manages each device in the user's manufacturing plant, and a vendor management system 2 for each device
11, 221, and 231 are connected to each other via the external network 200 such as the Internet or a dedicated line network. In this system, when trouble occurs in any of the series of production equipment on the production line,
Although the operation of the manufacturing line is suspended, it is possible to quickly respond by receiving remote maintenance via the Internet 200 from the vendor of the device in which the trouble has occurred, and the suspension of the manufacturing line can be minimized. .

Each manufacturing apparatus installed in the semiconductor manufacturing factory is provided with a display, a network interface, and a computer for executing the network access software and the apparatus operating software stored in the storage device. The storage device is a built-in memory, a hard disk, or a network file server. The network access software includes a dedicated or general-purpose web browser, and provides, for example, a user interface with a screen as shown in FIG. 11 on the display. The operator who manages the manufacturing device in each factory refers to the screen and refers to the model 401 of the manufacturing device, the serial number 402, and the subject 4 of the trouble.
03, date of occurrence 404, urgency 405, symptom 406, coping method 407, progress 408, etc. are input to the input items on the screen. The input information is transmitted to the maintenance database via the Internet, and the appropriate maintenance information as a result is returned from the maintenance database and presented on the display. In addition, the user interface provided by the web browser further includes hyperlink functions 410 to 410 as illustrated.
412 is implemented, the operator can access more detailed information on each item, extract the latest version of software used for the manufacturing equipment from the software library provided by the vendor, and use the operation guide (help Information) can be withdrawn. Here, the maintenance information provided by the maintenance database includes the information about the present invention described above, and the software library also provides the latest software for implementing the present invention.

Next, a semiconductor device manufacturing process using the above-described production system will be described. FIG. 12 shows the flow of the whole manufacturing process of the semiconductor device.
In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask manufacturing), a mask having the designed circuit pattern is manufactured. On the other hand, step 3
In (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by the lithography technique using the mask and the wafer prepared above. The next step 5 (assembly) is called a post-process, which is a process of forming a semiconductor chip using the wafer manufactured in step 4, and includes an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. Including steps. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes and shipped (step 7). The front-end process and the back-end process are performed in separate dedicated factories, and maintenance is performed for each of these factories by the remote maintenance system described above. Information for production management and device maintenance is also data-communicated between the front-end factory and the back-end factory via the Internet or the leased line network.

FIG. 13 shows a detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted in the wafer. Step 1
In 5 (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist image are removed. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. Since the manufacturing equipment used in each process is maintained by the remote maintenance system described above, troubles can be prevented in advance, and even if troubles occur, quick recovery is possible, and semiconductor devices can be compared to conventional devices. Productivity can be improved.

[0046]

As described above, according to the present invention, the surface position detecting system photoelectrically converts the reflected light from the light projecting portion for projecting the surface position detecting light to the substrate surface and the photoelectric conversion element to the substrate surface position. And a light receiving unit for determining the value of at least two pulse trains of a shift pulse for applying a drive pulse of each pixel as a photoelectric conversion element and a reset pulse for determining an accumulation section of the image pickup element are input. By applying the reset pulses having different phases to at least one of the image pickup devices, the surface position can be set at high speed and with high accuracy.

In the present invention, the surface position detection system is
Utilizing a light projecting unit for projecting surface position detection light to the substrate surface and a light receiving unit for photoelectrically converting the reflected light from the substrate by a photoelectric conversion element to obtain the substrate surface position, each pixel serving as the photoelectric conversion element. A plurality of one-dimensional or two-dimensional image pickup elements for inputting at least two pulse trains of a shift pulse for giving a drive pulse and a reset pulse for determining an accumulation section of the image pickup element are used, and the pixel scan directions of the image pickup elements are different from each other. The surface position can be set at high speed and with high accuracy also by detecting the height of the substrate based on the data from the plurality of image pickup elements arranged in the facing direction.

Further, in the present invention, in the scanning type exposure apparatus which projects a part of the pattern of the original onto the substrate through the projection optical system while exposing the original and the substrate relative to each other, the surface position setting according to any one of the above By providing the surface position setting device using the method, it is possible to set the substrate height at high speed and with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a main part of a slit scan type projection exposure apparatus including a surface position detection apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining operation timings of a wafer control system and a surface position detection system using a conventional surface position setting method.

FIG. 3 is a diagram showing a relationship between a wafer height measurement position and an exposure region position during wafer exposure.

FIG. 4 is a diagram for explaining operation timings of a wafer position control system and a surface position detection system using a conventional surface position setting method.

FIG. 5 is a diagram for explaining operation timings of a surface position detection system and a wafer control system using a plurality of image pickup devices according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of operation timings of a surface position detection system and a wafer position control system using a plurality of image pickup elements whose directions are opposite to each other according to the embodiment of the present invention.

FIG. 7 is a diagram showing an arrangement example of image pickup devices of a surface position detection system using a plurality of image pickup devices according to an embodiment of the present invention.

FIG. 8 is a diagram showing an example of an image pickup signal of a surface position detection system using a plurality of image pickup devices according to an embodiment of the present invention.

FIG. 9 is a conceptual view of a semiconductor device production system using the apparatus according to the present invention viewed from an angle.

FIG. 10 is a conceptual view of a semiconductor device production system using the apparatus according to the present invention viewed from another angle.

FIG. 11 is a specific example of a user interface.

FIG. 12 is a diagram illustrating a flow of a device manufacturing process.

FIG. 13 is a diagram illustrating a wafer process.

FIG. 14 is a diagram showing a state in which a light flux that has passed through a lens system is incident on and imaged at measurement points independent of each other in a pattern region in the embodiment of the present invention.

FIG. 15 is a diagram showing a plurality of pattern regions arranged on a wafer surface in the embodiment of the present invention.

[Explanation of symbols]

1: reduction projection lens, 2: reticle, 3: reticle stage, 4: wafer, 5: wafer stage, 6: exposure illumination optical system, 10: light source, 11: collimator lens, 12:
Prism-shaped slit member, 13: lens system, 14,
15: Bending mirror, 16: Light receiving lens, 17: Stopper diaphragm, 18: Correction optical system group, 19: Photoelectric conversion means group, 20: XY bar mirror, 21: Reticle stage interferometer, 22: Reticle position control system, 23: XY bar mirror, 24: Wafer stage interferometer, 25: Wafer position control system, 26: Surface position detection system, 27: Main control unit, 60
a, 60b: image sensor, 61: beam splitter, 6
2: Received light.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 7/11 MF term (reference) 2F065 AA03 AA24 BB02 BB15 CC20 DD06 FF04 FF51 GG02 GG04 GG06 GG07 HH12 HH14 JJ02 JJ25 LL28 LL30 LL59 MM02 MM04 PP12 QQ24 QQ31 2H051 AA10 BA72 CC04 5F046 BA05 CC15 DA13 DB05 DB11

Claims (11)

[Claims] 1. A surface position setting method in which a surface position detection system continuously detects and drives the surface position of a substrate suction-fixed on a stage that moves at least in the X, Y and height directions, while relatively scanning. The surface position detection system uses a light projecting unit that projects surface position detection light onto the substrate surface, and a light receiving unit that photoelectrically converts reflected light from the substrate by a photoelectric conversion element to obtain the substrate surface position. Then, as the photoelectric conversion element, a plurality of one-dimensional or two-dimensional image pickup elements for inputting at least two pulse trains of a shift pulse for giving a drive pulse of each pixel and a reset pulse for determining an accumulation section of the image pickup element are used, A surface position setting method, wherein reset pulses having different phases are applied to at least one of the image pickup devices. 2. A surface position setting method in which a surface position detection system continuously detects and drives the surface position of a substrate suction-fixed on a stage that moves in at least the X, Y and height directions while relatively scanning the surface position. The surface position detection system uses a light projecting unit that projects surface position detection light onto the substrate surface, and a light receiving unit that photoelectrically converts reflected light from the substrate by a photoelectric conversion element to obtain the substrate surface position. Then, as the photoelectric conversion element, a plurality of one-dimensional or two-dimensional image pickup elements for inputting at least two pulse trains of a shift pulse for giving a drive pulse of each pixel and a reset pulse for determining an accumulation section of the image pickup element are used, A surface position setting method characterized in that the height of the substrate is detected based on data from the plurality of image pickup elements arranged in different pixel scan directions. 3. A surface position setting device using the surface position setting method according to claim 1. 4. A scanning type exposure apparatus according to claim 3, which is a scanning type exposure apparatus which projects a part of a pattern of an original onto the substrate through a projection optical system while relatively scanning the original and the substrate, and exposing the substrate. An exposure apparatus comprising an apparatus. 5. A step of installing a manufacturing apparatus group for various processes including the exposure apparatus according to claim 4 in a semiconductor manufacturing factory, and a step of manufacturing a semiconductor device by a plurality of processes using the manufacturing apparatus group. A method of manufacturing a semiconductor device, comprising: 6. Data communication of information relating to at least one of the manufacturing apparatus group between the step of connecting the manufacturing apparatus group with a local area network and between the local area network and an external network outside the semiconductor manufacturing factory. The method for manufacturing a semiconductor device according to claim 5, further comprising: 7. A semiconductor manufacturing factory, which is different from the semiconductor manufacturing factory, accessing the database provided by the vendor or the user of the exposure apparatus via the external network to obtain maintenance information of the manufacturing apparatus by data communication. 7. The semiconductor device manufacturing method according to claim 6, wherein production control is performed by performing data communication with the device via the external network. 8. A manufacturing apparatus group for various processes including the exposure apparatus according to claim 4, a local area network connecting the manufacturing apparatus group, and an external network outside the factory accessible from the local area network. At least one of the manufacturing device group
A semiconductor manufacturing plant characterized by enabling data communication of information about a table. 9. The exposure apparatus maintenance method according to claim 4, wherein the vendor of the exposure apparatus or a user provides a maintenance database connected to an external network of the semiconductor manufacturing factory. And the process of
A step of permitting access to the maintenance database from the semiconductor manufacturing factory via the external network; and a step of transmitting the maintenance information accumulated in the maintenance database to the semiconductor manufacturing factory side via the external network. A method for maintaining an exposure apparatus, comprising: 10. The exposure apparatus according to claim 4,
An exposure apparatus further comprising a display, a network interface, and a computer that executes network software, and enables maintenance apparatus information to be data-communicated via a computer network. 11. The network software comprises:
A user interface for accessing a maintenance database provided by a vendor or a user of the exposure apparatus, which is connected to an external network of a factory in which the exposure apparatus is installed, is provided on the display, and from the database via the external network. The exposure apparatus according to claim 10, which enables information to be obtained.