JP3399697B2 - Measurement point mapping apparatus and semiconductor wafer measurement apparatus using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to, for example, a film thickness measuring device and the like, and is a measuring point mapping device used for positioning a substrate to be measured in a manufacturing process of a semiconductor device, a liquid crystal display device or the like, In particular, an image of a predetermined pattern formed on a substrate such as a semiconductor wafer is magnified with an optical microscope, the magnified image is captured as an input image, and the input image is matched with a reference image registered in advance. TECHNICAL FIELD The present invention relates to a measurement point mapping device used when performing positioning by using the method and a semiconductor wafer measuring device using the same.

[0002]

2. Description of the Related Art In the technical field of analysis or measurement,
To position the measurement point at the position where the measuring device performs measurement (hereinafter referred to as "measurement execution position") when the measurement is aimed at a desired portion of the substrate under measurement (hereinafter referred to as "measurement point") Generally, the pattern matching method is adopted. This is because the image of the area on the substrate to be measured that has a predetermined positional relationship with the measurement point (hereinafter referred to as the "reference image") is registered in advance, and the image is taken from the image of the substrate to be measured. Find the position that matches the image,
Therefore, the position of the measurement point is specified (Japanese Patent Application No. 4-
341586). In the conventional example, pattern matching is performed for all measurement points for positioning.

FIG. 14A is a partially enlarged view showing an example of a semiconductor wafer which is an object to be measured in the conventional example.
(b) is the AA sectional view. In this semiconductor wafer, as shown in the same figure, a silicon nitride film 1a and a silicon oxide film 2 which are patterned in a predetermined shape are formed on a semiconductor wafer 1. For example, in FIG.
The image of the portion indicated by the two-dot chain line in (a) is, as shown in FIG. 15, an image region (region 1) corresponding to a part of the silicon nitride film 1a and an image region corresponding to a part of the silicon oxide film 2. (Region 2). When the areas 1 and 2 are irradiated with light and the intensity of the reflected light is examined, the intensity of the area 1 is higher than that of the area 2. Therefore, the reference image is specified by capturing an image through an image capturing unit such as a camera and recognizing the pattern shown in FIG. 15 from the intensities of the light from both regions 1 and 2. Specifically, the registration process and the measurement process were performed according to the following procedure (pattern matching).

1) Registration Process First, a semiconductor wafer 1 serving as a reference is transferred from the outside to an XY stage having a coordinate reading function while positioning with a certain accuracy. Next, by operating the panel keys, XY
The stage is moved, the measurement point is aligned with the center of the visual field, and the coordinates are read. The stage moving operation and the coordinate reading operation are repeated a predetermined number of times to store a plurality of read coordinates (coordinates of each measurement point). Such coordinates are used as coordinate values for mechanical positioning of the measurement point before the pattern matching in the measurement process.

Then, an image near the measurement point is registered as a reference pattern. At the time of registering this pattern, the frame-shaped marking lines 5 and the cross-shaped marking lines 6 as shown in FIG. 16 are used. The frame-shaped marking lines 5 and the cross-shaped marking lines 6 can be individually moved within the screen 7 by operating panel keys. here,
The image surrounded by the frame-shaped marking lines 5 is an image used for pattern matching, and is the coordinates at which the intersection of the cross-shaped marking lines 6 is detected. Here, it is assumed that the pattern 8 shown in FIG. 17 is formed on all the chips of the semiconductor wafer 1. Then, the panel key is pressed to store the pattern 8 surrounded by the frame-shaped marking 5 (see FIG. 17) and also the relative position data between the pattern 8 and the measurement point (the intersection of the cross-shaped marking 6).

2) Measurement Processing Similar to the registration processing, the semiconductor wafer, which is the substrate to be measured, is first transferred from the outside onto the XY stage while being positioned with a predetermined accuracy. Then, the XY stage automatically moves to the coordinates of the first measurement point. At this time, the position of the measurement point in the field of view differs from that at the time of registration due to variations in the outer diameter of the wafer, positioning accuracy of the transfer device, and the like. Therefore, the pattern matching is executed to detect the position of the pattern, and the coordinates of the measurement point are calculated from the relative position data of the stored pattern and the intersection of the cross-shaped marking 6 with respect to the pattern. The coordinates of the measurement point calculated here and the position on the image of the measurement position of the optical system are calculated, and the stage is moved based on the calculation result to measure the film thickness and the like.

[0007]

As described above, in the conventional example, the above-described coordinate reading operation must be repeated for the desired number of measurement points in the registration process.
Therefore, when the thickness of the insulating film or the like is repeatedly measured at many measurement points on the surface of the semiconductor wafer 1, it takes a lot of time for the registration work as described above, which causes the work efficiency to deteriorate. It was

The present invention has been made to solve the above problems, and provides a measuring point mapping apparatus and a semiconductor wafer measuring apparatus using the measuring point mapping apparatus which can improve the working efficiency by shortening the working time in the registration process. The purpose is to provide.

[0009]

According to a first aspect of the present invention, a plurality of measuring points are provided on a substrate to be measured from which a plurality of chips are to be cut out. Is a device for allocating and allocating the plurality of chips, determining the coordinates of each of the plurality of measurement points, and mapping the plurality of chips relative to the substrate to be measured. Relative position data storage means for storing data, and representative measurement point coordinate storage means for storing the coordinates of a representative measurement point extracted from the plurality of measurement points based on the imaging result of the measured substrate, Based on the coordinates of the representative measurement points and the relative position data, the coordinates of each of the plurality of measurement points are calculated and obtained, thereby obtaining a coordinate map of the plurality of measurement points. And a ring means.

The problem solving means according to claim 2 of the present invention is
The measurement point mapping device according to claim 1, wherein the measurement point coordinate mapping means sets all the coordinates of the measurement point candidates that are set in association with all of the plurality of chips.
A part of the plurality of chips is calculated by receiving a designation from the selection designating means from among the obtained measurement point candidates while performing calculation based on the two-dimensional coordinates of a representative measurement point and the relative position data. The selected measuring point coordinate calculating means for selecting only the measuring points corresponding to the chip, and the selected measuring point coordinate storing means for storing the coordinates of each of the measuring points selected by the selecting measuring point coordinate calculating means.

The problem solving means according to claim 3 of the present invention is
A measuring device for performing measurement processing to the semiconductor wafer as a substrate to be measured, and a holding means for holding a pre-Symbol semiconductor wafer, and measuring means for performing the measurement process for the semiconductor wafer, the measurement point according to claim 2 Based on the result of imaging the semiconductor wafer in a state of being held at a position different from the mapping device and the mapping, the coordinates of the part corresponding to the measurement point selected by the selected measurement point coordinate calculation means are calculated. Based on the calculation result by the distance calculation means for calculating the distance between the selected measurement point corresponding site coordinate extraction means for extracting, the site corresponding to the extracted measurement point and the measurement execution position of the measurement means, By changing the relative position between the measurement execution position of the measurement means and the holding means, the portion corresponding to the selected measurement point is sequentially moved to the measurement execution position. And a moving means for.

[0012]

In the measuring point mapping device according to the first aspect of the present invention, first, the relative position data of the plurality of chips with respect to the substrate to be measured is input by the data input means and stored by the relative position data storage means. Next, the coordinates of the representative measurement point extracted from the plurality of measurement points are stored in the representative measurement point coordinate storage means. Then, the measurement point coordinate mapping means obtains a coordinate map of a plurality of measurement points.

In the second aspect, when the coordinate map of the plurality of measurement points is obtained by the measurement point coordinate mapping means, the coordinates of the representative measurement points stored in the representative measurement point coordinate storage means and the relative position data storage means are stored. From the relative position data
The selected measuring point coordinate calculating means calculates the coordinates of all measuring points that are candidates for measurement, and selects from among the obtained measuring point candidates, a part of a plurality of chips designated by the selecting and designating means. Select only the coordinates of the corresponding measuring points. And
Only the coordinates of the measurement points are stored in the selected measurement point coordinate storage means by the selected measurement point coordinate calculation means. Then, it becomes possible to extract and measure only a part of the measurement points as a sample at the time of measurement.

Further, in the case of the semiconductor wafer measuring apparatus according to the third aspect, when the measurement processing is repeatedly performed at a plurality of points on the semiconductor wafer 1, the time for mapping the measurement points becomes short.

[0015]

【Example】

<Description of Semiconductor Wafer> First, a semiconductor wafer 1 which is a substrate to be measured which is a processing target in one embodiment of the present invention will be described. The semiconductor wafer 1 is formed by patterning each thin film of a silicon nitride film 1a and a silicon oxide film 2 as shown in FIG. 1, and is cut along a lattice-shaped scribe line SC in the silicon oxide film 2 in a later process ( By dicing), it is divided into a plurality of chips. Then, at a plurality of predetermined positions on the semiconductor wafer 1 of this embodiment, a plurality of measurement points P1 as film thickness measurement points are set as shown in FIG. 2, for example. Such measurement point P1
May be set one by one in association with all chips as shown in FIG. 2, or some chips may be selected as samples and only the measurement points P1u corresponding to the chips are limited (selected). You may set it. Here, as shown in FIG. 1, the plurality of measurement points P1 are predetermined with respect to the arrangement of the patterns (thin films of the silicon nitride film 1a and the silicon oxide film 2) of each chip that are the targets of film thickness measurement. It is set to a predetermined position.

<Structure of Film Thickness Measuring Device> Next, the structure of the film thickness measuring device of this embodiment will be described. FIG. 3 is a diagram showing a film thickness measuring device to which the measuring point mapping device of this embodiment is applied, and FIG. 4 is a block diagram of the film thickness measuring device. In the following description, the structure and operation of the measurement point mapping device of the present embodiment will be clarified by describing the semiconductor wafer and the structure and operation of the film thickness measuring device.

The film thickness measuring apparatus of this embodiment corrects the positional deviation between the mapping coordinates created on the reference semiconductor wafer 1 and the semiconductor wafer 1 actually placed on the stage after using pattern matching. The film thickness is measured. As shown in FIGS. 3 and 5, the film thickness measuring device includes a measurement point mapping device 9 for determining and storing a plurality of measurement point coordinates for a semiconductor wafer 1 on which a plurality of chips having the same pattern are formed, and the measurement point mapping device. An illumination optical system 10 for irradiating the semiconductor wafer 1 mounted on the stage of the apparatus with illumination light, and an imaging optical system 20 for focusing reflected light from the semiconductor wafer 1 at a predetermined position to form an image. , A control unit 60 for controlling the position of the stage based on the imaging means
a (FIG. 5).

The measuring point mapping device 9 corresponds to each functional block realized by the CPU 61 according to a program stored in a memory 62 of a control unit 60 described later shown in FIG. 4, and as shown in FIG. a) to (c).

(A) Relative position data storage means 9a, (b) for storing relative position data for defining a design relative positional relationship of a plurality of chips with respect to the semiconductor wafer 1.
A representative measurement point that stores the coordinates on the XY stage of a representative measurement point P1s (hereinafter referred to as “representative measurement point”) extracted from the imaging result of the semiconductor wafer 1 and read by the XY stage encoder 32 attached to the XY stage. Coordinate storage means 9b, (c) The coordinates of each of the plurality of measurement points P1 are calculated based on the two-dimensional coordinates of the representative measurement point P1s on the XY stage and the relative position data. Measurement point coordinate mapping means 9c for obtaining a coordinate map of the plurality of measurement points P1.

The measuring point coordinate mapping means 9c
Has the following (j) and (k).

(J) All the coordinates of the measurement point (P1) candidates set in association with all of the plurality of chips are calculated based on the coordinates of the representative measurement point P1s and the relative position data. From the measurement point (P1) candidates, only the measurement point P1u corresponding to the part of the chips is selected based on the operation of the panel key 65 as the selection designating means (hereinafter, “selection measurement point”). In the present embodiment, as shown in FIG. 2, since the representative measurement point P1s is included in the selected measurement points P1u, a total of nine selected measurement points P1u are set.) Chip selection information is stored in the second CRT 75. Selected measurement point coordinate calculation means 9j to be displayed on (k) Selected measurement point P1 selected by the selected measurement point coordinate calculation means 9j
Selected measurement point coordinate storage means 9k for storing the coordinates of u.

Further, the illumination optical system 10 is provided with a light source 11 for emitting white light, and the light from the light source 11 is passed through a condenser lens 12, an aperture stop 13, a field stop 14 and a condenser lens 15. And enters the imaging optical system 20.

The image forming optical system 20 comprises an objective lens 21, a beam splitter 22 and an image forming lens 23. Illumination light from the illumination optical system 10 is reflected by the beam splitter 22 and a predetermined illumination is carried out via the objective lens 21. The position IL is irradiated. In addition, 24 in FIG. 3 has shown the pupil position.

The XY stage 30 (holding means) is arranged near the illumination position IL. The XY stage 30 moves in the X and Y directions in accordance with a control signal from the XY stage drive circuit 31 while mounting the semiconductor wafer 1 as a substrate to be measured, and an arbitrary region (imaging is performed on the surface of the semiconductor wafer 1 The desired area) is located at the illumination position IL. The XY stage 30 detects the position (X, Y coordinates) and gives the position information to the control unit 60a (FIG. 5) of the control unit 60 that controls the entire apparatus.
A Y stage encoder 32 is attached.

The light reflected by the image pickup area of the semiconductor wafer 1 located at the illumination position IL is focused on a predetermined image forming position via the objective lens 21, the beam splitter 22 and the image forming lens 23 as shown in FIG. It is illuminated and the image of the imaging area is enlarged and projected. A reflecting mirror 40 having a pinhole 41 at its center is arranged near the image forming position. Therefore, the reflected light LS that has passed through the pinhole 41 among the reflected light
Is incident on the spectroscopic unit 50 as a measuring means.

The spectroscopic unit 50 is composed of a diffraction grating 51 that disperses the reflected light LS, and a photodetector 52 that detects the spectroscopic spectrum of the diffracted light diffracted by the diffraction grating 51. As the diffraction grating 51, for example, a flat field type diffraction grating that forms a spectrum on a plane or a diffraction grating with a sweep mechanism can be used.
On the other hand, the photodetector 52 is composed of, for example, a photodiode array or CCD, and is arranged in a conjugate relationship with the pinhole 41. Therefore, the light LS taken into the spectroscopic unit 50 is dispersed by the diffraction grating 51, and a signal corresponding to the spectrum of the light LS is given from the photodetector 52 to the arithmetic circuit 53 (FIG. 4). The arithmetic circuit 53 obtains the film thickness of the thin film formed on the semiconductor wafer 1 based on the signal using a conventionally known method (the description thereof is omitted here), and outputs the result to the control unit 60. To do.

On the other hand, of the light from the semiconductor wafer 1, the reflected light reflected by the reflecting mirror 40 is incident on the image pickup unit 70. That is, in the image pickup unit 70, the reflected light from the reflecting mirror 40 is condensed on the image pickup surface 72 a of the two-dimensional image pickup camera 72 via the relay lens 71. As a result, an image of the image pickup area of the semiconductor wafer 1 is formed. The image signal related to the image (input image) captured by the two-dimensional image capturing camera 72 is displayed on the CRT 74 after being subjected to predetermined processing by the image processing unit 73 as shown in FIG. , To the control unit 60a of the control unit 60.

Further, as shown in FIG. 4, the control unit 60 stores in advance a well-known CPU 61 that executes a logical operation, various programs that control the CPU 61, and various data during operation of the apparatus. And a memory 62 for temporarily storing These CPU 61,
The memories 62 are connected to each other by a common bus 63, and the input / output port 6 is connected via the common bus 63.
4 is also connected. Then, the input / output port 64
Thus, the control unit 60 inputs and outputs signals to and from the outside, for example, the panel key 65, the XY stage drive circuit 31, the arithmetic circuit 53, the XY stage encoder 32, the second CRT 75, and the image processing unit 73. Give and receive.

Then, the control unit 6 in the control unit 60
As shown in FIG. 5, reference numeral 0a denotes a selected measurement point movement command means 81 for moving the XY stage 30 based on each coordinate stored in the selected measurement point coordinate storage means 9k during measurement,
Reference image storage means 84 that stores in advance a reference matching image for pattern matching for extracting a site P1u ′ corresponding to the selected measurement point corresponding to each selected measurement point P1u (hereinafter referred to as “selected measurement point corresponding site”). Then, pattern matching is performed between the image information from the image processing unit 73 at the time of measurement and the reference image information stored in the reference image storage means 84, and each selected measurement point stored in the selected measurement point coordinate storage means 9k. The selected measurement point corresponding part coordinate extracting means 87 for extracting the coordinates on the image of the selected measurement point corresponding part P1u ′ corresponding to P1u and the measurement execution position, that is, the pinhole 41, are optically preset. Position P3
A measurement target point storage unit 85 that stores in advance the coordinates on the image (hereinafter, this position is referred to as a “measurement target point”), and the coordinates on the image of the measurement target point P3 stored in the measurement target point storage unit 85. A distance calculation means for calculating the distance and direction with respect to the coordinates on the image of each selected measurement point corresponding part P1u ′ extracted by the selected measurement point corresponding part coordinate extraction means 87, and converting the calculated distance and direction on the XY stage 30. 86 and the site P corresponding to each selected measurement point based on the calculation result by the distance calculating means 86.
It is provided with a selected measurement point corresponding part movement instruction means 94 which issues a movement instruction signal to the XY stage drive circuit 31 so that 1u ′ coincides with the measurement target point P3.

The selected measurement point movement command means 81, the selected measurement point corresponding part coordinate extraction means 87, the measurement target point storage means 85, the distance calculation means 86 and the selected measurement point corresponding part movement command means 94 are stored in the memory 62. It corresponds to each functional block realized by the CPU 61 according to the stored program.

<Operation> Next, an outline of the operation of the above film thickness measuring apparatus will be described with reference to the flowchart of FIG. 6 (details will be described later). First, prior to actual film thickness measurement, the semiconductor wafer 1 for registration is used to determine and store a plurality of measurement point coordinates for film thickness measurement (measurement point mapping) and image position detection. The reference image is registered (step S1). Thereafter, the semiconductor wafer 1 to be actually measured is transported (step S2), and the selected measurement point corresponding portion P1u ′ is the measurement target point P3 with the image center.
The semiconductor wafer 1 is moved by driving the XY stage 30 so as to be in the vicinity of (step S3). At this point, position detection is performed (step S4), and the selected measurement point corresponding site P1u ′ is moved to the measurement target point P3 that is the measurement execution position (step S5). The measurement target point P3 is an immovable position that is optically preset corresponding to the pinhole 41. Then, the film thickness measurement is performed on the selected measurement point corresponding site P1u '(step S6). And
It is determined whether or not the measurement has been completed for all selected measurement point corresponding parts P1u '(step S7), and if not completed, the processing from step S3 is repeated. on the other hand,
When it is determined that the measurement is completed for all selected measurement point corresponding parts P1u ', the semiconductor wafer 1 is unloaded (step S8). The above operation is executed for the plurality of semiconductor wafers 1 (step S9), and when the measurement is completed for all the semiconductor wafers 1, the operation is ended. Here, the registration processing of step S1 and steps S4 to S
The position detection, movement, and film thickness measurement processing up to 6 will be described in detail.

1) Registration Process FIG. 7 is a flow chart showing the procedure of the registration process of this embodiment. In performing the registration process, first, the panel key 65 is used to input design relative position data of a plurality of chips with respect to the semiconductor wafer 1. Here, the relative position data refers to the following four types of data.

The size data of the semiconductor wafer 1 (orientation flat: including the position data of the orientation flat), the data of the arrangement of the chips in the semiconductor wafer 1, the position data of the center point of the semiconductor wafer 1, the center position of the semiconductor wafer 1. Data of the amount of offset (offset) of the chip to be moved from the center point.

It should be noted that the above-mentioned offset data is set in such a manner that the chip located at the center point is slightly moved in the XY directions from the center of the semiconductor wafer 1 when it is desired to maximize the amount of chips taken in the semiconductor wafer 1. Dimensions (eg 10
(mm × 10 mm) may be intentionally shifted and set. Here, the input relative position data is stored in the relative position data storage means 9a of the memory 62.

Next, the semiconductor wafer 1 for registration is conveyed to the XY stage 30 while positioning the semiconductor wafer 1 for registration with a constant accuracy by a handling machine (not shown) (step S).
11). Then, the operator operates the panel key 65 to move the XY stage 30 so that the representative measurement point P1s is located substantially at the center of the input image projected on the CRT 74 for any one of the chips. At this time, since a pinhole 41 is formed in the reflecting mirror 40, a black dot-like image (pinhole image) that always appears at the center of the input image is set as the measurement target point P3, and as shown in FIG. The XY stage 30 is moved so that the measurement target point P3 and the representative measurement point P1s coincide with each other. Then, the operator uses a key for registration (not shown) provided on the panel key 65.
When is pressed, the coordinate value of the representative measurement point P1s on the XY stage 30 is read from the XY stage encoder 32, and this coordinate value is stored in the representative measurement point coordinate storage means 9b of the memory 62 via the input / output port 64. (Step 1
2). Then, the selected measurement point coordinate calculation means 9j calculates the coordinate values of all the measurement points P1 from the relative position data input in step S10 and the coordinate values of the representative measurement point P1s stored in the representative measurement point coordinate storage means 9b. Is calculated as the measurement point candidate coordinates, and only the measurement point P1u corresponding to the selected chip is selected from the measurement point candidate coordinates based on the chip selection command from the panel key 65.

At this time, as shown in FIG.
A chip arrangement diagram of the semiconductor wafer 1 based on the relative position data of the chips stored in the relative position data storage means 9a is drawn therein, and a cross mark for selecting chips 93 is displayed. The cross-shaped mark 93 for chip selection is a panel key 65.
Can be moved up and down, left and right, and the movement is based on the relative coordinates of the representative measurement point P1s obtained first with respect to the tip, so that the relative position is always constant when moving to any tip. Has become. Therefore, the operator operates the panel key 65 to move the cross mark for selecting chips 93, and presses another key on the desired chip so that the controller can determine the actual measurement locations and number of all the measurement points. It is possible to instruct and select.
By this method, the selected measurement point coordinate calculation means 9j selects the measurement points P1u (“selection measurement points”) of several chips as measurement targets, and the selected measurement points P1u corresponding to the selected chips are selected. Only the coordinates are stored in the selected measuring point coordinate storage means 9k (step S13). The selection and storage of the selected measurement point P1u are repeated the number of times of measurement (9 times in this embodiment) (step S14). In the case of the present embodiment, the nine measurement points in FIG. 2 are registered and used as the selected measurement points, but the measurement points (P1) in the semiconductor wafer 1
All the candidates may be selected as the selected measurement point P1u.
In this way, the coordinate values of the plurality of selected measurement points P1u are stored in the selected measurement point coordinate storage means 9k.

After that, as shown in FIG. 10, the frame-shaped reference line 92 shown in the image drawn on the first CRT is moved up and down and left and right by the panel key 65, and the basic pattern desired to be used for pattern matching. While surrounding the image to be
By operating the panel key 65, the cross mark 91 is measured at the measuring point P.
1 and press a predetermined key in the panel key 65 to display the basic pattern shape, the basic pattern image and the measurement point P.
The relative position data with respect to 1 (the intersection of the cross-shaped gage 91) is registered in the reference image storage means 84 (step S15). Then, the semiconductor wafer 1 is unloaded (step S16), and the registration process is completed.

2) Position Detection, Movement and Film Thickness Measurement Processing Next, the position detection, movement and film thickness measurement operation will be described with reference to FIG. When the above registration process is completed,
The semiconductor wafer 1 to be the target of film thickness measurement is positioned with a constant accuracy by the handling machine and conveyed onto the XY stage 30 (step S31 in FIG. 11). Then, the selected measurement point movement command means 81 reads out the coordinates of the first selected measurement point P1ua stored in the selected measurement point coordinate storage means 9k, and drives the XY stage drive circuit 31 based on the read coordinates. 30 is moved (step S32 in FIG. 11). The positioning accuracy at this time has some error. Then, on the basis of the image from the image processing unit 73 and the reference image information stored in the reference image storage means 84, pattern matching is performed by the selected measurement point corresponding part coordinate extraction means 87 and the film thickness is actually measured 1 The coordinates on the image of the selected measurement point corresponding portion P1ua ′ of the point eye are extracted. (Step S33 in FIG. 11). From the obtained coordinates of the selected point corresponding site P1ua ′ on the image on the image and the coordinates of the measurement target point P3 (pinhole image) stored on the measurement target point storage means 85 on the image, The distance calculation means 86
The XY distance on the image from the selected measurement point corresponding portion P1ua ′ of the first point to the measurement target point P3 is calculated, and the distance is converted into the distance on the XY stage 30.
Then, based on the calculation result by the distance calculation means 86, the selected measurement point corresponding part movement command means 94 sends a movement signal to the XY stage drive circuit 31 to move the XY stage 30, and as shown in FIG. The selected measurement point corresponding part P1ua ′ is automatically matched with the position (step S34 in FIG. 11).

At this point in time, as shown in FIG. 12, the measurement execution position (that is, the measurement target point P3) coincides with the selected measurement point corresponding portion P1ua 'of the first point where the film thickness measurement is to be actually performed. As shown in 3, the reflected light LS that is incident on the spectroscopic unit 50 is dispersed, and this spectral spectrum is obtained.
Further, the film thickness at the selected point corresponding to the selected measurement point P1ua 'is obtained from the spectrum (step S35 in FIG. 11).

Thereafter, similarly, another selected measurement point P1
For u, the processes from step S32 to step S35 are repeated, the film thickness measurement is repeated up to the total number of selected measurement point corresponding parts (step S36), and then the semiconductor wafer 1 is unloaded (step S37).

<Modification> (1) In the above embodiment, the semiconductor wafer 1 has been described as being formed by patterning each thin film of the silicon nitride film 1a and the silicon oxide film 2. The material is not limited, and any other semiconductor material may be used as long as it can optically identify the boundary between the patterns (particularly, the corner points) by the brightness and the like. It may be of any stacking step in the semiconductor manufacturing process.

(2) In the above embodiment, even when all the measurement points (all of the measurement point candidates) are designated as the selected measurement points,
When all the measurement points are selected by the operator on the cross-shaped gaze mark 93, as shown in FIG. 13, a key selection is made as to whether or not all the measurement points are to be selected (step S17), and all the measurement points are selected. May be automatically calculated based on the relative position data stored in the relative position data storage means 9a (step S18).

[0043]

According to the first aspect of the present invention, relative position data of a plurality of chips with respect to the substrate to be measured is input by the data input means and stored by the relative position data storage means, and at the same time, a plurality of measurement points are stored. Only by storing the coordinates of the representative measurement points extracted from among them in the representative measurement point coordinate storage means, it is possible to obtain the coordinate map of the plurality of measurement points by the measurement point coordinate mapping means, so that the coordinates of the measurement points are extremely large. The effect is that mapping can be done efficiently and work time can be shortened.

According to claim 2 of the present invention, among all the measurement points that are candidates for measurement, only the measurement points on some chips as the measurement object are selected by the selection measurement point coordinate calculating means, and only the coordinates are selected. It can be stored in the selected measuring point coordinate storage means, and only a part of the measuring points can be sampled and measured at the time of measurement. Therefore, there is an effect that the measurement work time can be significantly shortened as compared with the case where the measurement is performed for all the chips.

According to the third aspect of the present invention, when the measurement processing is repeatedly performed at a plurality of points on the semiconductor wafer 1, the time for mapping the measurement points becomes short,
The measurement processing efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an enlarged view showing a surface of a semiconductor wafer on an image in an embodiment of the present invention.

FIG. 2 is a plan view showing a semiconductor wafer handled in one embodiment of the present invention and its measurement points.

FIG. 3 is a diagram showing a film thickness measuring device to which a measuring point mapping device according to an embodiment of the present invention is applied.

FIG. 4 is a block diagram of a film thickness measuring device to which a measuring point mapping device according to an embodiment of the present invention is applied.

FIG. 5 is a block diagram showing an internal configuration of a control unit according to an embodiment of the present invention.

FIG. 6 is a flowchart showing the operation of the film thickness measuring apparatus to which the measuring point mapping apparatus according to the embodiment of the present invention is applied.

FIG. 7 is a flowchart showing a procedure of registration processing of the measurement point mapping device according to the embodiment of the present invention.

FIG. 8 is an enlarged view showing the surface of the semiconductor wafer on the image in the embodiment of the present invention.

FIG. 9 is an enlarged view showing a state of a chip arrangement of a semiconductor wafer displayed when a chip is selected in the measurement point mapping device according to the embodiment of the present invention.

FIG. 10 is a diagram showing a state of a semiconductor wafer on an image in the registration processing according to the embodiment of the present invention.

FIG. 11 is a flowchart showing a procedure of position detection, movement, and film thickness measurement processing in the measurement point mapping device according to the embodiment of the present invention.

FIG. 12 is a diagram showing a state of a semiconductor wafer on an image in a film thickness measurement process of an example of the present invention.

FIG. 13 is a flowchart showing a procedure of registration processing of a measurement point mapping device according to still another embodiment of the present invention.

FIG. 14 is a diagram showing a semiconductor wafer in a conventional measurement point mapping device.

FIG. 15 is a diagram showing a portion within a frame-type marked line in an image captured by a conventional measurement point mapping device.

FIG. 16 is a diagram showing a frame-shaped marking line and a cross-shaped marking line in an image in a conventional example.

FIG. 17 is a diagram showing a frame-shaped marking line and a cross-shaped marking line in an image in a conventional example.

[Explanation of symbols]

1 Semiconductor wafer 1a Silicon nitride film 2 Silicon oxide film P1 measurement point P1s representative measurement point P1u selection measurement point P3 measurement target point 9 Measuring point mapping device 9a Relative position data storage means 9b Representative measuring point coordinate storage means 9c Measuring point coordinate mapping means 9j Selected measurement point coordinate calculation means 9k selection measurement point coordinate storage means 10 Illumination optical system 20 Imaging optical system 30 XY stage 31 XY stage drive circuit 32 X stage encoder 40 Reflector 41 pinhole 50 spectroscopic unit 60 control unit 60a control unit 70 Imaging unit 81 Selection measurement point movement command means 84 reference image storage means 87 Selection Measurement Point Corresponding Part Coordinate Extraction Means 85 measurement target point storage means 86 Distance calculation means 94 Selective measurement point corresponding part movement command means 91 Cross Mark 92 Frame type marking 93 Cross mark for chip selection

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Claims (3)

(57) [Claims] 1. On a substrate to be measured from which a plurality of chips are to be cut out, a plurality of measurement points are allocated to all or a part of the plurality of chips, and the coordinates of each of the plurality of measurement points are allocated. An apparatus for determining and mapping, wherein relative position data storage means for storing relative position data for defining a design relative positional relationship of the plurality of chips with respect to the measured substrate, and imaging of the measured substrate. Based on the result, a representative measurement point coordinate storage means for storing the coordinates of the representative measurement point extracted from the plurality of measurement points, based on the coordinates of the representative measurement point and the relative position data, Calculate the coordinates of each of the plurality of measurement points,
A measurement point mapping device comprising: a measurement point coordinate mapping means for obtaining a coordinate map of the plurality of measurement points. 2. The measurement point mapping device according to claim 1, wherein the measurement point coordinate mapping means sets all the coordinates of the measurement point candidates set in association with all of the plurality of chips to the representative. While calculating based on the two-dimensional coordinates of the measurement point and the relative position data,
Selected measurement point coordinate calculation means for selecting only measurement points corresponding to some of the plurality of chips by receiving designation from the selection designation means from the obtained measurement point candidates, and the selected measurement A measuring point mapping device comprising: selected measuring point coordinate storing means for storing the coordinates of each measuring point selected by the point coordinate calculating means. 3. A measuring apparatus for the measurement process performed on the semiconductor wafer as a substrate to be measured, and a holding means for holding a pre-Symbol semiconductor wafer, and measuring means for performing the measurement process for the semiconductor wafer, wherein Item 2. The measurement point mapping device according to item 2, and based on the result of imaging the semiconductor wafer in a state where the semiconductor wafer is held at a position different from that at the time of mapping, the measurement point selected by the selected measurement point coordinate calculation unit is set. Selected measurement point corresponding part coordinate extraction means for extracting the coordinates of the corresponding part, distance calculation means for calculating the distance between the part corresponding to the extracted measurement point and the measurement execution position of the measurement means, and calculation by the distance calculation means Based on the result, the relative position between the measurement execution position of the measuring means and the holding means is changed, whereby the regions corresponding to the selected measurement points are sequentially moved forward. A semiconductor wafer measuring apparatus, comprising: a moving unit that moves the measurement wafer to a measurement execution position.