JP2665487B2 - Wafer peripheral exposure system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist for a peripheral portion of a resist applied to the surface of a semiconductor wafer, a ceramic wafer, or the like having a circular portion and a linear portion (orientation flat). The present invention relates to an apparatus for exposing a peripheral portion of a wafer, which removes the wafer by exposure.

[0002]

2. Description of the Related Art In recent years, a positive resist is often used as a resist applied to the surface of a semiconductor wafer, a ceramic wafer or the like. In this case, before (or after) performing the required pattern exposure, the peripheral portion of the wafer is exposed to remove the resist in the peripheral portion of the wafer.

If a single light irradiating means is fixedly installed at a predetermined distance from the center of the wafer and the wafer is exposed while rotating the wafer, the periphery of the arc (hereinafter referred to as the arc) is exposed. Even if it is possible, since the irradiation light passes outside the wafer in the peripheral portion of the linear portion whose distance from the center of the wafer is shorter than the arc portion (hereinafter referred to as the linear portion), the linear portion cannot be exposed.

Therefore, conventionally, a plate cam which is similar to the wafer and rotates synchronously with the wafer is provided, and a cam follower attached to the light irradiation means is moved along the plate cam to make the linear portion substantially the same as the arc portion. It is possible to devise the exposure by the width (plate cam method), or to provide a means for mechanically or optically detecting the edge of the wafer (the boundary between the arc and the straight line) and to detect the edge of the wafer. Then, from the stage where the exposure point moves from the arc to the linear part, the light irradiating means is rotated by adjusting the distance from the wafer center to the light irradiating means so that the irradiation position is along the linear part by rotating the wafer. In this case, the linear portion is exposed with substantially the same width as the arc portion (edge detection method).

[0005]

However, the basic idea of these conventional systems is that both the arc portion and the straight portion are exposed during continuous rotation of the wafer at a constant speed, and the exposure width of the arc portion and the straight line To make the exposure width of the part the same,
This has led to the following inconveniences.

As shown in FIG. 6, when the light irradiating means (relatively) goes around the wafer end We, the exposure width L near the wafer end We is due to the angular shape of the wafer end We. ₁ is smaller than the exposure width L ₀ of the other part. This appears more strongly in the linear portion Ws of the wafer, and a linear exposure, that is, the same width of exposure cannot be performed in the linear portion Ws itself.

For the same reason as described above, as shown in FIG. 7, when the light irradiation means Mv goes around the wafer end We, within the same time, the inner exposure length l ₁ and the outer exposure length l ₁ Is significantly different from l ₂ (l ₁ <
l ₂ ) Further, since the exposure length of each point in the width direction is different from each other, the exposure amount per unit area in the same time varies, and uniform exposure cannot be performed.

Since the resist is applied to the surface of the wafer W by the spin method, as shown in FIG. 8, the resist accumulates in the end region on the upper side in the wafer rotation direction among both ends of the linear portion Ws. This region is a thick film region Wa of the resist (see hatching).
The width of the thick film area Wa is usually larger than the uniform exposure width L ₀ , but when the exposure width is fixed, it is required to expose the entire thick film area Wa. In addition, part of the thick film region Wa remains without being substantially removed, and it is difficult to meet the demand.

When a wafer is handled in a subsequent step, a key portion of the wafer W is gripped by a clamp claw k as shown in FIG. 9, but in order to stabilize the clamp, a clamp area Wk is formed with a uniform exposure width L. _Make it larger than ₀ .
If the resist in the clamp area Wk is not removed, the resist peels off when it is gripped by the clamp claws k, and adheres on the pattern of the wafer W or contaminates the device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and exposes both an arc portion and a linear portion during continuous rotation of a wafer at a constant speed, and furthermore, the exposure width of the arc portion and the linear portion. It is an object of the present invention to eliminate the above-mentioned inconvenience caused due to the fact that the basic idea is to make the exposure width the same as the above.

[0011]

The present invention has the following configuration in order to achieve the above object. That is, according to the first aspect of the present invention, there is provided a rotating unit for rotating a wafer having a circular portion and a linear portion in a peripheral portion, a light irradiating unit for exposing a peripheral portion of the wafer, and a linear portion for detecting a linear portion of the wafer. A line sensor for detection, a rotation angle calculation unit for obtaining rotation angle information of the current wafer based on the detection of the linear portion of the wafer by the line sensor for linear portion detection, and the light irradiation unit with respect to a rotation center of the rotation unit. Radial displacement means for relatively approaching and separating, and tangential displacement means for relatively displacing the light irradiation means with respect to the rotation means along a direction perpendicular to the displacement direction of the radial displacement means. An exposure width setting means for setting an exposure width according to a rotation angle; and an exposure width according to a rotation angle at that time from the exposure width setting means based on rotation angle information from the rotation angle calculation means. Based on the set exposure width read out, the radial displacement means is driven to adjust the position of the light irradiating means with respect to the circular arc portion of the wafer, and the rotation angle information obtained by the rotation angle calculation means is used to adjust the position of the wafer linear part. When the start of exposure is indicated, with the rotating means stopped, the radial displacement means is driven to position the light irradiation means with respect to the linear portion of the wafer, and then the tangential displacement means is driven. Control means for relatively linearly displacing the light irradiation means along the linear portion of the wafer.

As notes on this configuration, the following (a) to
(c).

(A) The radial displacement means may displace the light irradiation means with respect to the rotation means, or may displace the rotation means with respect to the light irradiation means.

(B) The tangential displacement means may displace the light irradiating means with respect to the rotating means, or may displace the rotating means with respect to the light irradiating means.

(C) The control means may perform the exposure control on the wafer arc portion after performing the exposure control on the wafer linear portion, or may perform the control in the reverse order.

According to a second aspect of the present invention, there is provided a rotating device for rotating a wafer having a circular portion and a linear portion, a light irradiating unit for exposing a peripheral portion of the wafer, and a detecting device for detecting a linear portion of the wafer. A linear sensor for detecting a linear portion, a rotation angle calculator for obtaining current rotation angle information of the wafer based on the detection of the linear portion of the wafer by the linear sensor for detecting the linear portion, and a rotation of the rotating device. Radial displacement means for relatively approaching and separating from the center, exposure width setting means for setting an exposure width according to the rotation angle, and the rotation angle calculated by the rotation angle calculation means were monitored and monitored. When the rotation angle reaches a change point of the exposure width set by the exposure width setting means, the driving of the rotation means is stopped, and the exposure width is read from the exposure width setting means according to the rotation angle at that time. The radial direction displacement means is driven to adjust the position relative to the wafer peripheral portion of the light irradiating means, it is characterized in that a resume control means for driving the rotation means.

As a note in this configuration, the following (d),
(e).

(D) The radial displacement means may displace the light irradiation means with respect to the rotation means, or may displace the rotation means with respect to the light irradiation means.

(E) The control means may adjust the position of the light irradiating means based on the set exposure width according to the rotation angle with respect to the wafer arc portion or may perform the position adjustment with respect to the linear wafer portion. Or both.

[0020]

The operation of the first aspect of the invention is as follows. Based on the rotation angle information, the radial displacement means is driven in accordance with the set exposure width according to the rotation angle at that time to adjust the position of the light irradiation means with respect to the wafer arc, so that the exposure width is variable for each rotation angle. It becomes possible. Further, when exposing the linear portion of the wafer, the light irradiating means is linearly displaced along the linear portion of the wafer by driving the tangential displacement means when the rotating means (wafer) is stopped. The width can be made the same.

According to the second aspect of the present invention, the rotation angle is monitored, and when the monitored rotation angle reaches a change point of the exposure width set by the exposure width setting means, the rotation means is rotated. The driving is stopped, the radial displacement means is driven to the exposure width read out from the exposure width setting means in accordance with the rotation angle at that time, and the position of the light irradiation means with respect to the wafer peripheral portion is adjusted. Since the driving of the means is restarted, the exposure width can be made variable for each rotation angle.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, the mechanical and optical structure of the wafer peripheral exposure apparatus will be described with reference to the perspective view of FIG.

A rotating shaft of the spin chuck 1 for horizontally rotating the wafer W while sucking and holding the wafer W is connected to a first motor M1. The spin chuck 1 and the first motor M1 correspond to the rotating means Mθ in the configuration of the present invention.

The light source section is composed of a mercury xenon lamp 2, an elliptical mirror 3, an ultraviolet transmission filter 4, a shutter 5 and the like, and is configured to guide the ultraviolet light passing through the filter 4 to its irradiation end 6a by an optical fiber 6. is there. The portion from the lamp 2 to the irradiation end 6a corresponds to the light irradiation means Mv in the configuration of the present invention. More precisely, the irradiation end 6a corresponds to the light irradiation means Mv.

With respect to the shape of the ultraviolet spot irradiated from the irradiation end 6a of the optical fiber 6 to the peripheral portion of the wafer W, if the spot is circular, the spot is positioned with respect to the center of the spot in the radial direction of the wafer. At both end positions (a position near the center of the wafer and a position far from the center of the circular spot), the integrated light amount is small, so that exposure and, consequently, resist removal may be non-uniform. It is preferable to achieve uniformity.

A fiber support arm 7 for holding an irradiation end 6a at the tip of the optical fiber 6 is attached to an XY table 8. The XY table 8 includes an X table 8x, a second motor M2 for reciprocating the X table 8x in the X direction, a Y table 8y placed on the X table 8x, and a Y table 8y And a third motor M3 for reciprocating the motor in the Y direction. The fiber support arm 7 is attached to the Y table 8y.

The X direction is a direction from the irradiation end 6a toward the rotation center of the spin chuck 1, and the Y direction is a direction perpendicular to the X direction.

The X table 8x and the second motor M2 constitute a radial displacement means Mx according to the present invention, and the Y table 8y and the third motor M3 constitute a tangential displacement means My according to the present invention. Make up.

The first to third motors M1 to M3
Is a stepping motor.

A line sensor 9 as a linear portion detecting line sensor A for detecting the linear portion Ws of the wafer W which is rotated while being attracted and held by the spin chuck 1 is arranged corresponding to the rotation locus of the peripheral portion of the wafer W. ing.

FIG. 2 shows another embodiment of the mechanical structure of the wafer peripheral exposure apparatus.
10y is provided. The one-axis table 10x holds the optical fiber irradiation end 6a via the fiber support arm 7, and is reciprocated in the X direction by the second motor M2. The one-axis table 10y is attached with a first motor M1 as a rotating means Mθ and a spin chuck 1, and is reciprocated in the Y direction by a third motor M3.

In this embodiment, the one-axis table 10x and the second motor M2 correspond to the radial displacement means Mx, and the one-axis table 10y and the third motor M3 correspond to the tangential displacement means My.

Note that, instead of the structure shown in FIGS. 1 and 2, the radial displacement means Mx may be configured to displace the rotation means Mθ (the first motor M1 and the spin chuck 1). Alternatively, the fiber support arm 7 of the light irradiation means Mv may be fixed, and the rotation means Mθ may be attached to the XY table 8.

Next, a method of detecting the linear portion Ws of the wafer W sucked and held by the spin chuck 1 and a method of obtaining the current rotation angle information of the wafer W based on the detection of the linear portion will be described.

The center of the wafer W is aligned with the rotation center of the spin chuck 1 by an alignment mechanism (not shown). When the center alignment is completed, vacuum suction is performed in the spin chuck 1, and the wafer W is sucked to the spin chuck 1.

The first motor M1 drives the wafer W
Is rotated, the number of cells that are turned ON among the cells of the line sensor 9 is constant while the arc portion Wc passes over the line sensor 9. From this state, the number of cells where the line sensor 9 is turned on increases at the moment when one of the wafer ends We, which is the boundary between the straight line portion Ws and the arc portion Wc, passes. Due to this increase in the number of ON cells, one wafer edge We
Can be detected.

When the wafer W further rotates, the rotation of the wafer W is continued until the center of the linear portion Ws reaches the line sensor 9.
The number of N cells continues to increase, and after the center, the number of ON cells decreases from the maximum value. Then, when the other wafer edge We passes through the line sensor 9, the number of ON cells changes from a decreasing state to a constant state. By this change, the other wafer edge We can be detected.

The motor M1 is a stepping motor and has a built-in pulse encoder (not shown). If the rotation angle corresponding to the number of pulses from the origin position of the pulse encoder to the detection of one wafer end We is θ1, and the rotation angle corresponding to the number of pulses until the other wafer end We is detected is θ2, Angle α = ｛(θ2
−θ1) / 2｝ + θ1 where the number of pulses corresponds to
It is the rotation angle from the origin position to the center of the linear portion Ws. This is the reference angle of the wafer W.

After calculating the reference angle α at the center of the linear portion Ws in this way, the motor M1 is stopped when the wafer W is rotated one more revolution and the number of pulses corresponding to the reference angle α is detected. Is stopped in a state where the linear portion Ws is parallel to the displacement direction of the tangential displacement means My, that is, the Y direction. Then, in this state, the tangential displacement means My is driven to perform linear exposure on the wafer linear portion Ws.

The wafer W while the wafer W is rotating
Can be obtained by adding an angle corresponding to the difference between the number of pulses from the origin position to the present and the number of pulses up to the reference angle α to the reference angle α.

Next, the configuration and operation of the control system of each of the first and second wafer peripheral exposure apparatuses will be described.
The first wafer peripheral exposure apparatus does not directly correspond to the present invention, but is used to facilitate understanding of the operation of the present invention (especially, the invention described in claim 1). is there.

<First Wafer Peripheral Part Exposure Apparatus> In the block diagram of FIG. 3, A is a linear part detecting line sensor corresponding to the line sensor 9 described above, and B is a linear part detecting line sensor A. Detection of wafer linear portion Ws,
And a rotation angle calculation means for obtaining a reference angle α of the wafer W and current rotation angle information θt that changes every moment based on the output of the pulse encoder in the rotation means Mθ.
C is an exposure width setting means for setting the arc portion exposure width Lc and the linear portion exposure width Ls independently of each other.

Mθ is a means for rotating the wafer W corresponding to the first motor M1 and the spin chuck 1, and Mv is
Light irradiating means corresponding to the lamp 2, shutter 5, optical fiber 6, etc., Mx is the aforementioned radial displacement means, My is the tangential displacement means, E is the rotation angle information θt and the set exposure width (Lc or Ls). ), The rotation means Mθ,
Control means for controlling the light irradiation means Mv, the radial displacement means Mx, and the tangential displacement means My.

The wafer W transferred to the spin chuck 1
After being centered by an alignment mechanism (not shown), is held by the spin chuck 1 by suction. The control means E drives the rotation means Mθ (first motor M1) to rotate the spin chuck 1 in one direction. On the other hand, the rotation angle calculation means B calculates the reference angle α based on the angles θ1 and θ2 from the origin position input from the linear portion detection line sensor A [α = {(θ2−θ1) / 2}. +
θ1] (see FIG. 4A).

The control means E inputs the reference angle α and continues to drive the rotating means Mθ. The rotation angle calculating means B compares the rotation angle information θt, which changes from time to time, from the origin position input from the linear portion detection line sensor A even at the second rotation with the reference angle α, and when θt = α Then, a stop command signal is output to the control means E. The control means E receives the signal and stops the rotation means Mθ. At this time, the wafer W stops in a state where the linear portion Ws is parallel to the displacement direction of the tangential displacement means My, that is, the Y direction (see FIG. 4B).

Next, the operation proceeds to the preparation operation for linear portion exposure. That is, the control means E reads the linear portion exposure width Ls from the exposure width setting means C, and drives the radial displacement means Mx based on this to drive the wafer linear portion Wx of the light irradiation means Mv.
Positioning for s is performed. At the same time or before and after, the tangential displacement means My is driven to drive the light irradiation means Mv.
Is positioned outside the end of the linear portion Ws of the wafer (see FIG. 4C).

The control means E opens the shutter 5 of the light irradiation means Mv to start irradiation of ultraviolet rays from the optical fiber irradiation end 6a, and drives the tangential displacement means My to move the light irradiation means Mv in the Y direction. Linearly, and the linear portion exposure width Ls of the wafer linear portion Ws is linearly set by the ultraviolet rays from the optical fiber irradiation end 6a.
Are exposed uniformly (see FIG. 4D). When the optical fiber irradiation end 6a passes through the other end of the linear portion Ws of the wafer, the shutter 5 is closed.

Next, the operation moves on to the preparation operation for the arc exposure. That is, the control means E drives the rotation means Mθ to rotate the wafer W by the reference angle α, and drives the tangential displacement means My in the opposite direction to return the light irradiation means Mv to its original position. Next, the control means E reads the arc width exposure width Lc from the exposure width setting means C, and drives the radial displacement means Mx based on the read to position the light irradiation means Mv with respect to the wafer circular arc portion Wc (FIG. 4). (E)).

The control means E opens the shutter 5 of the light irradiation means Mv to restart the irradiation of the ultraviolet light from the optical fiber irradiation end 6a, and drives the rotating means Mθ to move the wafer W to the light irradiation means Mv. By rotating the wafer, the wafer arc portion Wc is uniformly exposed with the ultraviolet light from the optical fiber irradiation end 6a within the arc portion exposure width Lc (FIG. 4).
(F)). The optical fiber irradiating end 6a is positioned at the wafer arc W
After passing the end of c, the shutter 5 is closed. Then, the radial displacement means Mx is driven to return the light irradiation means Mv to the origin position.

As described above, the wafer linear portion Ws is exposed with a uniform exposure width over the entire length of the linear portion Ws. The exposure is performed with an exposure width Ls independent of the exposure width Lc of the wafer arc Wc.

In this example of operation, the control means E performs the exposure of the arc portion Wc before the exposure of the linear portion Ws, but performs the exposure of the arc portion Wc first. Straight section W
The exposure of s may be performed later.

Further, the arc portion exposure width Lc and the linear portion exposure width L
How to select the set value of s is arbitrary, and both exposure widths Lc and Ls can be freely changed under appropriate and various combinations according to conditions and purposes.

<Second Wafer Peripheral Exposure Apparatus> This second wafer peripheral exposure apparatus corresponds to an embodiment of the present invention.

In this case, it has basically the same configuration as the block diagram shown in FIG. However, the exposure width setting means C
Can be set more finely than the exposure width in a large division such as an arc portion Wc and a straight line portion Ws. In particular, in the arc portion Wc, the exposure width L (θ _t according to the rotation angle θt can be set. ) Is set. The control means E reads an exposure width L (θ _t ) corresponding to the rotation angle θt at that time from the exposure width setting means C based on the rotation angle θt, and obtains a radius based on the exposure width L (θ _t ). Driving the direction displacement means Mx to irradiate the light irradiation means Mv
The position of the wafer W is adjusted.

The control means E drives the rotation means Mθ to rotate the wafer W, while the rotation angle calculation means B calculates the reference angle α based on the detection signal of the linear portion detection line sensor A (FIG. 5 (a)).

After calculating the reference angle α, the control means E calculates
The driving of the rotating means Mθ is stopped once, and the operation moves to the preparation operation for exposure. That is, the control unit E reads the exposure width L (θ _t0 ) corresponding to the stop angle θt ₀ from the exposure width setting unit C, and drives the radial displacement unit Mx based on the read exposure width L (θ _t0 ) to thereby control the wafer arc of the light irradiation unit Mv. Positioning with respect to the portion Wc is performed (see FIG. 5B).

The control means E opens the shutter 5 of the light irradiation means Mv, starts irradiation of ultraviolet rays from the optical fiber irradiation end 6a, and drives the rotation means Mθ to rotate the wafer W while rotating the wafer W. (Figure 5)
(C)). During this time, the current rotation angle θt calculated by the rotation angle calculation means B based on the signal from the pulse encoder of the rotation means Mθ is constantly monitored.

When the rotation angle θt reaches the change point θt ₁ of the exposure width, the control means E stops the rotation means Mθ. Then, the exposure width L (θ _t1 ) read from the exposure width setting means C
, The radial direction displacement means Mx is driven to adjust the position of the light irradiating means Mv with respect to the wafer arc portion Wc again (see FIG. 5D).

Again, while rotating the rotating means Mθ to rotate the wafer W, the circular arc portion Wc is exposed with a new exposure width L (θ _t1 ). When the rotation angle θt reaches the change point θt ₂ of the exposure width again, the control means E stops the rotation means Mθ and sets the radius based on the exposure width L (θ _t2 ) read from the exposure width setting means C. The direction displacement means Mx is driven, and the position adjustment is performed again with respect to the wafer arc portion Wc of the light irradiation means Mv (see FIG. 5E).

Note that L (θ _t2 ) = L (θ _t0 ) <l
(Θ _t1 ). This is for removing the resist in the clamp area Wk by the clamp claw k.

In this manner, a wide clamp area Wk is exposed at a plurality of locations in the wafer arc Wc (see FIG. 5F).

[0062] Incidentally, when exposure to wafer straight portion Ws is intended to adjust finely stepwise exposure width by the rotation angle [theta] t _i for each of the exposure width L (θ _ti). That is,
The exposure based on the set exposure width according to the rotation angle is also performed on the linear portion Ws. In this case, the tangential displacement means My becomes unnecessary.

Alternatively, upon detection of the wafer edge We, the wafer linear part Ws is made parallel to the Y direction as shown in FIG. 4B, and the light irradiation means Mv is moved linearly by driving the tangential displacement means My. The portion Ws may be exposed.

As another method, the wafer W is rotated twice, and in the first rotation, the narrow exposure width L (θ _t0 ) is fixed as a constant exposure width, and continuous exposure is performed by making one round with the constant exposure width. In the second rotation, the wide exposure width L (θ _t1 ) is fixed as a constant exposure width, and the shutter 5 is opened and exposed only when the rotation angle at the wide width is matched,
In another angle range, the shutter 5 may be closed.

[0065]

As is apparent from the above description, according to the first aspect of the present invention, the position of the light irradiating means with respect to the circular arc portion of the wafer is adjusted in accordance with the set exposure width according to the current rotation angle. By setting the exposure width to be larger than the other angle positions at the angular position to be gripped by the clamp claws in the subsequent process, it becomes possible to expose the clamp region with a larger width than the other regions. Therefore, it is possible to prevent inconvenience such that the resist is peeled off when the clamp area is gripped by the clamp claws and adheres to the pattern of the wafer or contaminates the apparatus.

Further, when the thick film region is wide, only the thick film region can be exposed with a wide width, so that the entire thick film region can be exposed.

According to the second aspect of the present invention, similarly to the first aspect, when the clamp area is exposed with a larger width than the other areas, or when the thick film area is large, only the thick film area is exposed with a wide width. Exposure is possible, so that contamination of the wafer and the apparatus can be prevented, and the entire thick film region can be exposed.

According to the first aspect of the present invention, in addition to the above, when exposing the linear portion of the wafer, the light irradiation means is linearly displaced along the linear portion of the wafer while the rotation of the wafer is stopped. Accordingly, exposure can be performed with the same exposure width over the entire length of the linear portion.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a mechanical and optical structure of a wafer peripheral exposure apparatus.

FIG. 2 is a perspective view showing the structure of another embodiment of the wafer peripheral exposure apparatus.

FIG. 3 is a block diagram of a wafer peripheral exposure apparatus.

FIG. 4 is an operation explanatory view of a first wafer peripheral exposure apparatus.

FIG. 5 is an explanatory view of the operation of the second wafer peripheral exposure apparatus.

FIG. 6 is a diagram for pointing out a conventional problem.

FIG. 7 is a diagram for pointing out another conventional problem.

FIG. 8 is a diagram for pointing out still another conventional problem.

FIG. 9 is a diagram for pointing out still another conventional problem.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spin chuck 2 ... Mercury xenon lamp 5 ... Shutter 6 ... Optical fiber 6a ... Irradiation end 7 ... Fiber support arm 8 ... XY table 9 ... Line sensor 10x, 10y ... Uniaxial table W ... Wafer Wc ... Wafer arc part Ws ... Linear portion of wafer Mθ ... Rotating means Mv ... Light irradiating means Mx ... Radial direction displacing means My ... Tangential direction displacing means A ... Linear part detecting line sensor B ... Rotation angle calculating means C ... Exposure width setting means E ... Control means θt … Rotation angle L (θ _t )… Exposure width according to rotation angle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Go Takada 322 Hahazushi Furukawacho, Fushimi-ku, Kyoto Nippon Screen Manufacturing Co., Ltd. Nippon Screen Manufacturing Co., Ltd. Rakusai Office (56) References JP-A-3-218619 (JP, A) JP-A-2-101734 (JP, A) JP-A-1-132124 (JP, A) JP-A JP-A-2-114628 (JP, A) JP-A-1-243427 (JP, A) JP-A-1-192117 (JP, A) JP-A-2-114629 (JP, A) JP-A-2-114630 (JP, A) A) Hikaru 1-112041 (JP, U)

Claims (2)

(57) [Claims] 1. A rotating means for rotating a wafer having a circular part and a linear part at a peripheral part, a light irradiating means for exposing a peripheral part of the wafer, a linear part detecting line sensor for detecting a linear part of the wafer, Rotation angle calculation means for obtaining current rotation angle information of the wafer based on the detection of the linear part of the wafer by the line sensor for linear part detection; and A radial displacement means for causing the light irradiation means to relatively displace relative to a rotation means in a direction perpendicular to a displacement direction of the radial displacement means; An exposure width setting unit for setting an exposure width; and an exposure width corresponding to a rotation angle at that time is read from the exposure width setting unit based on rotation angle information from the rotation angle calculation unit. The position of the light irradiating unit with respect to the circular arc portion of the wafer is adjusted by driving the radial displacement unit based on the set exposure width that has been issued, and the rotation angle information by the rotation angle calculation unit indicates the start of exposure of the wafer linear portion. When the rotating means is stopped, the radial displacement means is driven to position the light irradiation means with respect to the linear portion of the wafer, and then the tangential displacement means is driven to drive the light irradiation means. Control means for relatively linearly displacing along a linear portion of the wafer. 2. A rotating means for rotating a wafer having a circular arc portion and a linear portion, a light irradiating means for exposing a peripheral portion of the wafer, a linear portion detecting line sensor for detecting a linear portion of the wafer, Rotation angle calculation means for obtaining current rotation angle information of the wafer based on the detection of the linear part of the wafer by the line sensor for linear part detection; and A radial displacement means for causing an exposure width to be set according to a rotation angle; an exposure width setting means for setting an exposure width in accordance with the rotation angle; and a rotation angle calculated by the rotation angle calculation means. When the change point of the set exposure width is reached, the driving of the rotating means is stopped, and the radial displacement means is driven to the exposure width read from the exposure width setting means according to the rotation angle at that time. And a control means for adjusting the position of the light irradiating means with respect to the peripheral part of the wafer by moving the light irradiating means and restarting the driving of the rotating means.