JPH09266156A - End position detector, peripheral exposure apparatus and end position detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly detect an end position of a substrate even with respect to a light transmission type substrate. SOLUTION: A light source is provided at a position above a light transmission type substrate 1b, and a CCD line sensor 42 is provided opposite to the light source at a position below the light transmission type substrate 1b. An output signal from the CCD line sensor 42 is scanned from a photoreceptor cell corresponding to a reference position P0 outside of the light transmission type substrate 1b, toward the rotational central axis side. The position of a photoreceptor cell where the output signal from the CCD line sensor 42 has first changed from ON state to OFF state is assumed to be an end position of the light transmission type substrate 1b, and thereafter, if the length of a photoreceptor cell area indicative of OFF state has become a predetermined value, e.g. a length corresponding to a chamfer portion of the circumference of the substrate, the assumed end position is set as a regular end position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge position detecting device used for detecting an edge position of a substrate, an edge position detecting method, and a peripheral exposure apparatus equipped with the edge position detecting device.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, a resist solution is spin-coated on a substrate such as a semiconductor wafer, developed into a predetermined pattern, a resist mask is formed, and a thin film pattern is formed using the resist mask. That is being done.

The substrate on which the resist solution has been spin-coated is gripped at the peripheral edge thereof and conveyed between various substrate processing apparatuses. However, the resist solution is applied by spin coating to the peripheral portion of the substrate. Therefore, when the peripheral edge of the substrate is grasped, the resist on the peripheral edge is peeled off and scattered to contaminate the resist film surface in the central portion or to contaminate other substrate surfaces, thereby lowering the yield of substrate processing. It may end up.

For this reason, a peripheral exposure device is used to previously expose the resist on the peripheral portion of the substrate, and at the same time when the resist pattern is developed, unnecessary resist on the peripheral portion of the substrate is removed.

FIG. 6 is a schematic block diagram of a conventional peripheral exposure apparatus. In FIG. 6, the peripheral exposure apparatus includes a rotating unit 10 for holding and rotating the substrate 1, a light irradiating unit 20 for irradiating the resist film with an exposure light beam with a constant width along the outer peripheral edge of the substrate 1, A position detector 40 for detecting the rotational position and the edge position of the substrate 1 is provided.

The rotating means 10 comprises a spin chuck 11 for sucking and holding the back surface of the substrate 1, and a motor 12 for rotating the spin chuck 11. Further, the light irradiation means 20 is a light source (not shown) that generates an exposure light beam.
An optical fiber 23 for transmitting the exposure light beam, and an irradiation end 21 for irradiating the peripheral portion of the substrate 1 with the exposure light beam.
The irradiation end 21 is fixed to the tip of the support arm 22. The support arm 22 is moved by the moving means (not shown) to X.
It is formed so as to be movable in the direction and the Y direction orthogonal thereto.

The substrate position detector 40 has a light source 41 arranged above the substrate 1 and a CCD line sensor 42 arranged on the lower surface side of the substrate 1 so as to face the light source 41. In the CCD line sensor 42, a large number of light receiving cells are linearly arranged along the radial direction of the substrate 1. Then, when the parallel light emitted from the light source 41 arranged facing above the CCD line sensor 42 enters the light receiving cell of the CCD line sensor 42, the signal output from the light receiving cell is turned on (light receiving state). The signal output from the light receiving cell to which the parallel light is not incident indicates the off state (light shielding state).

An output signal from the CCD line sensor 42 is output to a substrate position detecting section (not shown) and a predetermined position detecting process is performed. A linear cutout portion (orientation flat; hereinafter abbreviated as an orientation flat portion) R formed by linearly cutting a part of a disk is formed on the substrate 1. Therefore, in order to perform peripheral exposure with a constant width along the outer peripheral edge of the substrate 1, it is necessary to detect the edge positions of the arc portion and the linear cutout portion of the substrate 1 in advance.

Therefore, in the conventional peripheral exposure apparatus, the edge position of the substrate 1 is detected by the substrate position detector 40 and the substrate position detector before performing the peripheral exposure. The operation of detecting the substrate edge position will be described below.

FIG. 7 is an explanatory diagram of the detection operation of the edge position of the substrate. Here, it is assumed that a silicon wafer 1a is used as the substrate and a resist 2 is applied to the surface thereof.

As shown in FIG. 7, the CCD line sensor 4
2 has a large number of light-receiving cells arranged linearly from the inside to the outside of the peripheral edge of the silicon wafer 1a. The innermost light receiving cell is arranged at the reference position P ₀ . The distance from the rotation center axis P _C of the spin chuck 11 in FIG. 6 to the reference position P ₀ is predetermined.

The silicon wafer 1a is a spin chuck 11.
The edge portion is located between the light source 41 and the CCD line sensor 42 while being held by the. The silicon wafer 1a is a light blocking substrate. Therefore, when the parallel light 43 is emitted from the light source 41, the parallel light 43 emitted to the surface of the silicon wafer 1a is blocked, and the parallel light 43 does not enter the light receiving cells below the silicon wafer 1a. Therefore, the output signals from these light receiving cells are turned off.

The parallel light 43 passing through the region outside the edge of the silicon wafer 1a reaches the light receiving cell as it is. Therefore, the output signals from these light receiving cells are turned on.

In the lower diagram of FIG. 7, the horizontal axis is
The position of the light receiving cell is shown, and the vertical axis shows the on / off state of each light receiving cell.
The state is shown. The board position detector is a CCD line sensor.
The signal output from the controller 42 is used as the reference position P ₀Is the light receiving cell of
Detection end position P_eThe scanning is performed in the order of the light receiving cells. So
The signal corresponding to each light receiving cell from the off state to the on state.
The position that changes for the first time is the substrate edge position P_EDetected as
I do.

The reference position P₀To substrate edge position P_E
Distance to L (called edge distance) L_AReceive light between
It is calculated based on the number of cells. Edge distance L_AIs sought
Then, the preset reference position P₀And rotation center axis P
_C(See FIG. 6) Edge distance L_ACan be added
By, the rotation center axis P _CTo the edge of the board
Can be

As described above, in the conventional peripheral exposure apparatus, C
The output signal from the CD line sensor 42 is scanned outward from the center side of the light-shielding substrate, and the position where the output signal changes from the off state to the on state first is detected as the edge position of the substrate. .

[0017]

However, in recent years,
For example, in a liquid crystal display device or the like, a substrate having a light-transmitting property in a visible light wavelength region such as a quartz wafer or a lithium tantalate wafer has been used. It has been pointed out that it is necessary to remove unnecessary resist by peripheral exposure even with such a transparent substrate.

Therefore, in the course of the invention, the inventors examined whether or not the conventional edge position detecting method in the peripheral exposure apparatus can be applied to such a transparent substrate. 8 to 10 are explanatory views of the edge position detecting operation when the conventional edge position detecting method is applied to the transparent substrate.

FIG. 8 shows an edge position detecting operation when a light shield is not formed on the surface of the transparent substrate 1b. The parallel light 43 emitted from the light source 41 is reflected by the resist 2
Then, the light passes through the transparent substrate 1b and reaches the light receiving cells of the CCD line sensor 42 between the reference position P ₀ and the position P ₁₁ . Therefore, the output signals from these light receiving cells show the ON state.

Further, the parallel light 43 does not reach the light receiving cells between the positions P ₁₁ and P _E. That is, the end surface of the translucent substrate 1b in the meantime is chamfered, and the parallel light 43 is reflected at this chamfered portion, and the CC below
This is because it does not reach the light receiving cell of the D line sensor 42. Therefore, the output signal from the light receiving cell corresponding to the chamfered portion of the transparent substrate 1b is turned off.

The CCD line sensor 4 according to the conventional method
When the output signal from the 2 scans toward the light receiving cell side of the detection end position P _e from the light receiving cell side of the reference position P _0, from the reference position P ₀ up to the position P ₁₁ is turned on is detected. In addition, a position P that passes through the chamfered portion of the transparent substrate 1b.
_The off state is detected between _{11 and} P _E. Further, the ON state is detected between the position P _E and the detection end position P _e .

In the conventional method, the CCD line sensor 42 is used.
The output signal from the first transitions from the off state to the on state.
The determined position is determined as the edge position of the substrate. For this reason
Place P ₁₁Changes in the signal at_ESmell
Position P _EIs the edge of the transparent substrate 1b
Detected as a position. Then, the reference position P₀From
Edge distance L_AIs calculated correctly.

Therefore, in the case shown in FIG. 8, the correct edge position can be detected even with the transparent substrate 1b. Next, FIG. 9 and FIG. 10 show the edge position detecting operation when the thin film pattern 3 made of aluminum, silicon, or the like is formed on the surface of the transparent substrate 1b. These thin film patterns 3 serve as light shielding regions. Therefore, when the light-transmissive substrate 1b on which the thin film pattern 3 is formed is irradiated with the parallel light 43, the thin film pattern 3 and the chamfered portion of the edge of the substrate serve as light shielding regions.

Therefore, first, in the case shown in FIG. 9, CC
The output signal from the D line sensor 42 is the reference position P _0-
The OFF state is shown between the position P ₂₁ and the position P ₂₂ to the position P _E , and the remaining position P ₂₁ to the position P ₂₂ and the position P _E.
The ON state is shown between the position P _e and the position P _e .

When the conventional method is applied to this output signal, the output signal is scanned from the reference position P ₀ side, and the position where the output signal changes from the OFF state to the ON state is detected as the substrate edge position first. . Therefore, in the case shown in FIG. 9, the position P ₂₁ is erroneously detected as the edge position of the transparent substrate 1b. Therefore, the wrong edge distance L _X
Is calculated.

In the case shown in FIG. 10, the output signal from the CCD line sensor 42 is in the off state between the positions P ₃₁ and P ₃₂ and between the positions P ₃₃ and P _E.
The remaining positions P ₀ to P ₃₁ , the positions P ₃₂ to P ₃₃ , and the positions P _E to P _e show the ON state.

Therefore, the position P _{32 at} which the output signal from the CCD line sensor 42 changes from the OFF state to the ON state first is erroneously detected as the edge position of the transparent substrate 1b.

From such examination results, the present inventors have recognized that the conventional edge position detecting method may erroneously detect the edge position with respect to the transparent substrate 1b. An object of the present invention is to provide an edge position detecting device, a peripheral exposure device and an edge position detecting method capable of correctly detecting the substrate edge position even on a transparent substrate.

[0029]

The edge position detecting device according to the first aspect of the invention is an edge position detecting device for detecting the edge position of a substrate, and is arranged on one surface side of the substrate. , A light projecting means for projecting light onto a predetermined area extending from the outer side to the inner side of the peripheral edge of the substrate, and arranged on the other surface side of the substrate so as to face the light projecting means, and receives the transmitted light from the predetermined area. However, the light receiving means for outputting the light receiving signal corresponding to the predetermined area and the light receiving signal output from the light receiving means in the direction from the outside to the inside of the substrate are changed from the light receiving state to the light shielding state first and the light shielding state is changed. And a detection means for detecting the edge position of the substrate based on the first change point from the light receiving state to the light shielding state when the light receiving state continues for a predetermined length or longer.

An edge position detecting apparatus according to a second aspect of the present invention is the edge position detecting apparatus according to the first aspect of the present invention, in which the substrate has a chamfered portion at a peripheral portion and a predetermined length is the chamfered portion. It corresponds to the width.

An edge position detecting device according to a third aspect of the present invention is the structure of the edge position detecting device according to the first or second aspect, wherein the light projecting means includes a light source for projecting light on a predetermined area. The light receiving means includes a line sensor including a plurality of light receiving portions linearly arranged at a position corresponding to the predetermined area.

A peripheral exposure apparatus according to a fourth invention is the first,
It is provided with an edge position detecting device according to the second or third aspect of the invention, and an exposing means for exposing the peripheral portion of the substrate based on the detection result of the edge position detecting device.

An edge position detecting method according to a fifth aspect of the present invention is an edge position detecting method for detecting an edge position of a substrate, which extends from the outside to the inside of the peripheral portion of the substrate on one surface side of the substrate. In the direction from the outside to the inside of the substrate, the step of projecting light on the predetermined region, the step of receiving the transmitted light from the predetermined region on the other surface side of the substrate and outputting the light receiving signal corresponding to the predetermined region, Detecting the edge position of the substrate based on the first change point from the light receiving state to the light blocking state when the light receiving signal first changes from the light receiving state to the light blocking state and the light blocking state continues for a predetermined length or longer. It is equipped with.

In the edge position detecting device according to the first to third inventions and the edge position detecting method according to the fifth invention,
Usually, a chamfered portion is provided in the peripheral portion of the substrate, and this chamfered portion reflects light regardless of whether the substrate is a light-transmissive substrate or a light-shielding substrate.

That is, when light is projected onto a predetermined area extending from the outer side to the inner side of the peripheral edge of the substrate, the light reaches the light receiving means in the outer area of the substrate, while the light is emitted in the chamfered portion of the peripheral edge of the substrate. Since it reflects light, it does not reach the light receiving means.

Therefore, when the light receiving signal from the light receiving means is scanned from the outside to the inside of the substrate, the light receiving signal first changes from the light receiving state to the light shielding state at the edge position of the substrate. Then, in the region corresponding to the chamfered portion of the substrate, the light receiving signal maintains the light blocking state. Therefore, the detection unit can detect the edge position of the substrate not only when the substrate has a light-shielding property but also when the substrate has a light-transmitting property by detecting such a change in the received light signal.

In particular, in the edge position detecting device according to the second aspect of the invention, since the predetermined length corresponds to the width of the chamfered portion of the substrate, the position of the chamfered portion of the substrate can be determined without being affected by noise. can do.

In particular, in the edge position detecting device according to the third aspect of the invention, the light receiving state and the light blocking state in the predetermined area can be detected with a simple structure by combining the light source and the line sensor.

In particular, the peripheral exposure apparatus according to the fourth invention is
By providing the edge position detection device according to the first to third inventions, not only the light-shielding substrate but also the light-transmitting substrate,
The edge position of the substrate can be correctly detected, and thereby the peripheral exposure processing of the transparent substrate can be accurately performed.

[0040]

1 is a perspective view showing the structure of an edge exposure apparatus according to an embodiment of the present invention. This peripheral exposure apparatus includes a substrate rotating unit 10 for holding and rotating a substrate,
A light irradiation unit 20 that irradiates a peripheral portion of the substrate with a light beam to expose it.
A moving unit 30 for moving the irradiation position of the light beam from the light irradiation unit 20 and a substrate position detector 40 are provided.

The substrate rotating unit 10 is composed of a spin chuck 11 for sucking and holding the back surface of the substrate 1 and a motor 12 for rotating the spin chuck 11 around a rotation center axis P _C.

The light irradiating section 20 is an exposure light source 28 for generating ultraviolet rays as an exposure light beam, an optical fiber 23 for transmitting the ultraviolet rays from the exposure light source 28, and is attached to the tip of the optical fiber 23 and of the substrate 1. An irradiation end 21 for irradiating the surface with ultraviolet rays is provided. The exposure light source 28 includes a mercury-xenon lamp 25, an elliptic mirror 26, an ultraviolet transmission filter 24, and a shutter 27.

The moving section 30 is composed of a radial displacement section Mx and a tangential displacement section My for displacing the support arm 22 supporting the irradiation end 21 in the X and Y directions in the figure. Further, the radial displacement portion Mx is reciprocally movable in the X direction by the X table 31 and the X table 3.
And a motor 32 for moving 1. The tangential direction displacement portion My is composed of a Y table 33 movable in the Y direction and a motor 34 for moving the Y table 33.

The substrate position detector 40 comprises a light source 41 arranged above the substrate 1 and a CCD line sensor 42 arranged below the substrate 1 so as to face the light source 41. The CCD line sensor 42 has a large number of light receiving cells linearly arranged along the radial direction of the substrate 1 from the rotation center axis P _C passing through the center of the spin chuck 11. When the light beam from the light source 41 enters the light receiving cell, the output signal of the light receiving cell is turned on, and when the light beam from the light source 41 is blocked, the output signal of the light receiving cell is turned off.

The operation of each section of the peripheral exposure apparatus is controlled by the control section. FIG. 2 is a functional block diagram of the peripheral exposure apparatus. The control unit D is composed of a central processing unit, and includes substrate edge position detecting means A, exposure width setting means B, exposure amount setting means C, substrate rotating section 10, light irradiation section 20, radial displacement section Mx and tangential direction. The operation of each part of the displacement part My is controlled.

The substrate edge position detecting means A receives the output signal from the CCD line sensor 42 and the rotation amount data of the motor 12 from the substrate rotating portion 10, and detects the rotation position of the substrate 1 and the substrate 1 at the rotation position. The edge position is detected.

The exposure width setting means B is arranged at the edge position of the substrate 1,
That is, the circular arc portion and the straight cutout portion (orientation flat portion) R
The exposure width of the exposure area in which the peripheral exposure is to be performed is set based on the position information. The exposure amount setting means C sets the exposure amount to the area where the peripheral exposure is to be performed.

In the peripheral exposure apparatus having the above structure, first, the edge position of the substrate 1 is detected, and then the peripheral exposure processing is performed. Here, as described in the section of the related art, in the conventional edge position detecting operation of the substrate, the inventors may sometimes erroneously detect the edge position when the substrate is translucent. It has been revealed by examination. Therefore, the peripheral exposure apparatus of the present invention is configured so that the correct edge position can be detected not only on the light-shielding substrate but also on the light-transmitting substrate.

The operation of detecting the edge position of the transparent substrate will be described below. FIG. 3 is an explanatory diagram of an edge position detection operation of the transparent substrate 1b. The upper diagram of FIG. 3 shows a cross section of the substrate position detector 40. In the lower diagram of FIG. 3, the horizontal axis indicates the position of the light receiving cell, and the vertical axis indicates on / off of each light receiving cell. It shows the state.

As shown in FIG. 3, the CCD line sensor 4
Of the two light receiving cells, the light receiving cell furthest outward from the peripheral portion of the transparent substrate 1b is set to the reference position P ₀ . The distance from the reference position P ₀ and the rotation center axis P _C is obtained in advance.

(Step 1) Substrate edge position detecting means A
(See FIG. 2) is each light receiving cell of the CCD line sensor 42.
The output signal from the reference position P₀Side light receiving cell
Rotation center axis P in order from _COutput signal toward the light receiving cell on the side
To start scanning.

(Step 2) The position P _E of the light receiving cell where the output signal from the CCD line sensor 42 first changes from the ON state to the OFF state is temporarily set as the edge position of the transparent substrate 1b.

(Step 3) Further, the length from the position P _E where the output signal of the CCD line sensor 42 has changed to the OFF state to the position where it returns to the ON state again is calculated, and the length of this OFF region becomes a predetermined value. When it reaches, it is determined that the off region has detected the chamfered portion of the transparent substrate 1b.

Here, in the transparent substrate 1b or the light-shielding substrate, the chamfered portion has a horizontal length of at least 200 μm.
It is set to m or more. Therefore, the predetermined value for determining the chamfered portion is set to 200 μm.

When the chamfered portion is detected, the position P _E provisionally determined in step 2 is set as the edge position P _E of the transparent substrate 1b. Then, the edge position P _E and the reference position P ₀
And the edge distance L _E is calculated.

The length of the off region is less than the predetermined value.
In this case, the signal indicating the off state is due to noise.
Then, the process of step 2 is continued again. (Step 4) Edge distance L_EIs determined in advance,
Set reference position P₀And rotation center axis P _CUsing the distance to
Rotation center axis P_CTo the edge of the transparent substrate 1b
Calculate the distance.

Through the above procedure, the transparent substrate 1b
The edge position of is detected. In addition, FIG. 4 shows a transparent substrate 1.
It is explanatory drawing which shows the edge position detection method in case the light-shielding thin film pattern 3 is formed on b. Also in this case, the edge position of the substrate is determined to be the position P _E regardless of the ON / OFF state of the output signal of the CCD line sensor 42 by the thin film pattern 3.

The above method utilizes the fact that the chamfered portion is formed at the edge of the transparent substrate 1b and the chamfered portion is a light-shielding region. The fact that the chamfered portion serves as a light-shielding region is common whether the substrate has a light-transmitting property or a light-shielding property. Therefore, for the transparent substrate 1b, not only when there is no light-shielding region such as a thin film pattern on the surface of the transparent substrate 1b as shown in FIG. 3, but also as shown in FIG. Even when the pattern 3 is formed, the edge position of the transparent substrate 1b can be correctly detected by the same detection method.

FIG. 5 is a flow chart specifically showing an example of the edge position detecting method of this embodiment. Hereinafter, FIG.
The edge position detecting method shown in FIG. 5 will be described with reference to FIG. In FIG. 5, i is a variable indicating the arrangement order of the light receiving cells when the light receiving cell at the reference position P ₀ is 1, and N
_OFF is a variable indicating the number of light-receiving cells that output a signal indicating the OFF state.

At the beginning of the detection operation, the variable i is set to 0 (step S2). Further, the variable N _{OFF is} also set to 0 (step S4). Next, the variable i is incremented to set the order i of the light receiving cells to be detected. First, it is set to a value indicating the first light receiving cell (step S
6).

The substrate edge position detecting means A detects the output signal corresponding to the i-th light receiving cell from the output signal of the CCD line sensor 42 (step S8). Then, it is determined whether the output signal indicates the on state or the off state.

For example, in FIG. 3, when i = 1, the parallel light 43 is not shielded by the transparent substrate 1b, so that the output signal from the i-th light receiving cell shows the ON state. Therefore, the process returns to step S4, and the output signal of the next light receiving cell is detected (step S10).

The operations of steps S4 to S10 are repeated until the light receiving cell at the position P _E. And the position P
_When the output signal from the light receiving cell of _E is determined to be in the off state (step S10), the process proceeds to the next step.

In the next step, the number of light-receiving cells that are in the off state is counted. That is, the variable N _OFF indicating the number of light receiving cells in the off state is incremented by 1 (step S12).

Then, a variable N indicating the light receiving cell in the off state
_It is determined whether _OFF is greater than a predetermined number N _{0 of} light receiving cells serving as a reference for detecting the chamfered portion of the transparent substrate 1b (step S14).

[0066] The more, from the reference position P ₀ (i-
N _OFF ) The reference position P ₀ based on the number of light receiving cells up to
Is calculated, and this distance is calculated as the distance (edge distance) L _{E to} the edge of the transparent substrate 1b (step S16).

The variable N_OFFIs the predetermined number N₀Below
If so, the process returns to step S6 to detect the output signal of the next light receiving cell.
Put out. Further, in step S10, whether the next cell
If the output signal from those
The signal in the full state is considered to be due to noise. And re
Once again returns to step S4 and outputs the off-state signal
Variable N indicating the number of cells _OFFReset. And
The detection operation after step S6 is repeated.

Through the above procedure, the transparent substrate 1b
The edge position of is correctly detected. Further, in the peripheral exposure apparatus of this embodiment, the transparent substrate 1 is formed by the above method.
When the edge position of b is detected, the exposure width setting means B shown in FIG. 2 calculates the exposure width of the exposure area around the transparent substrate 1b based on the information of the edge position, and the exposure amount setting means. C sets the exposure amount.

Then, the radial displacement portion Mx and the tangential displacement portion My are set to the light irradiation portion 20 based on the exposure width data.
The irradiation end 21 is moved to expose the circular arc portion of the transparent substrate 1b and the peripheral portion of the linear cutout portion.

In the above embodiment, the transparent substrate 1
The length for determining the chamfered portion of b (20 in the above example)
The value of 0 μm) can be set arbitrarily. Further, the method of detecting the substrate position detector 40 and the substrate edge position detecting portion A as described above is applied not only to a substrate having a linear cutout portion but also to a disc-shaped substrate having no linear cutout portion. Can be applied. Furthermore, it is also possible to detect the peripheral position of a rectangular substrate such as a liquid crystal display.

[Brief description of drawings]

FIG. 1 is a configuration perspective view of a peripheral exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of the peripheral exposure apparatus shown in FIG.

FIG. 3 is an explanatory diagram of an edge position detection operation of a substrate.

FIG. 4 is an explanatory diagram of an edge position detection operation of another substrate.

FIG. 5 is a flowchart showing a procedure for detecting an edge position of a substrate.

FIG. 6 is a configuration perspective view of a conventional peripheral exposure apparatus.

7 is an explanatory diagram of a substrate edge position detecting method in the peripheral exposure apparatus shown in FIG.

FIG. 8 is an explanatory diagram of a detection operation when a conventional edge position detection method is applied to a transparent substrate.

FIG. 9 is an explanatory diagram of a detection operation when the conventional edge detection method is applied to another transparent substrate.

FIG. 10 is an explanatory diagram of a detection operation when the conventional edge detection method is applied to another transparent substrate.

[Explanation of symbols]

1 substrate 1b translucent substrate 2 resist 10 substrate rotating unit 11 spin chuck 12 motor 20 light irradiation unit 21 irradiation end 30 moving unit 40 substrate position detector 41 light source 42 CCD line sensor 43 parallel light P ₀ reference position P _E substrate end Edge position L _E Edge distance

Claims (5)

[Claims] 1. An edge position detecting device for detecting an edge position of a substrate, wherein the edge position detecting device is arranged on one surface side of the substrate and projects light onto a predetermined region extending from the outer side to the inner side of a peripheral portion of the substrate. And a light receiving unit that is disposed on the other surface side of the substrate so as to face the light projecting unit, receives light transmitted from the predetermined region, and outputs a light reception signal corresponding to the predetermined region. The light receiving state when the light receiving signal output from the light receiving means changes from the light receiving state to the light shielding state first in the direction from the outside to the inside of the substrate and the light shielding state continues for a predetermined length or more. And an edge position detecting device that detects an edge position of the substrate based on a first change point from the light shielding state to the light shielding state. 2. The edge position detecting device according to claim 1, wherein the substrate has a chamfered portion at a peripheral edge thereof, and the predetermined length corresponds to a width of the chamfered portion. 3. The light projecting unit includes a light source that projects light onto the predetermined region, and the light receiving unit includes a line that includes a plurality of light receiving units linearly arranged at positions corresponding to the predetermined region. The edge position detecting device according to claim 1 or 2, further comprising a sensor. 4. An edge position detecting device according to claim 1, 2 or 3, and an exposing means for exposing a peripheral portion of the substrate based on a detection result of the edge position detecting device. Peripheral exposure device. 5. An edge position detecting method for detecting an edge position of a substrate, which comprises: projecting light on a predetermined area extending from outside to inside of a peripheral portion of the substrate on one surface side of the substrate. Receiving the transmitted light from the predetermined area on the other surface side of the substrate and outputting a light reception signal corresponding to the predetermined area; and the light reception signal being received in the direction from the outside to the inside of the substrate. Detecting the edge position of the substrate based on the first change point from the light receiving state to the light shielding state when the state first changes to the light shielding state and the light shielding state continues for a predetermined length or longer. A method for detecting an edge position, characterized by being provided.