JPH08213297A - Exposure device for wafer periphery - Google Patents

Abstract

PURPOSE: To allow a straight line exposure with the same width for a straight line part by performing the alignment for the wafer circular arc part of a light irradiating means according to the exposure width which is set in response to the rotation angle. CONSTITUTION: Based on the rotation angle information, the exposure width is read out in response to the rotation angle for each time by an exposure width setting means, and based on the read out set exposure width, adjustment is performed for the alignment of a light irradiating means Mv with a wafer circular arc part Wc by driving a means which is provided for displacement in the radius direction. When the rotation angle information from a rotation angle calculating means indicates the exposure start of a wafer straight line part Ws, alignment of the light irradiating means Mv with the wafer straight line part Ws is performed by driving the means which is provided for displacement in the radius direction, under the condition that the rotating means is stopped. Then, the light irradiating means Mv is displaced relatively along the wafer straight line part Ws by driving the means which is provided for displacement in the tangent line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wafer, a ceramics wafer, etc. having a circular arc portion and a linear portion (orientation flat) at the peripheral portion thereof. The present invention relates to a wafer peripheral exposure apparatus for removing a 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 required distance from the center of the wafer and the wafer is exposed while being rotated, the peripheral portion of the arc portion (hereinafter referred to as the arc portion) is exposed. Even if it is possible, the irradiation light passes through the outside of the wafer in the peripheral portion of the straight line portion (hereinafter, referred to as the straight line portion) whose distance from the wafer center is shorter than the circular arc portion, so that the straight line portion cannot be exposed.

Therefore, conventionally, a plate cam which is similar to the wafer and rotates in synchronism with the wafer is provided, and a cam follower attached to the light irradiation means is moved along the plate cam so that the straight line portion is almost the same as the arc portion. Detecting the wafer edge while providing a device to detect the width of the wafer (plate cam method) or mechanically or optically detecting the wafer edge (the boundary between the arc portion and the straight line portion) Then, from the stage where the exposure position shifts from the arc portion to the linear portion, by rotating the wafer while adjusting the distance from the wafer center to the light irradiation means so that the irradiation position of the light irradiation means is along the linear portion. , It was devised so that the straight line portion was exposed with almost 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,
For this reason, the following inconveniences have been brought about.

As shown in FIG. 6, when the light irradiation means wraps around the wafer edge We (relatively), the exposure width L near the wafer edge We is due to the angular shape of the wafer edge We. ₁ becomes 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.

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

[0011]

The present invention has the following constitution in order to achieve such an 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. The radial displacement means is driven based on the read out exposure width to adjust the position of the light irradiation means with respect to the arc portion of the wafer, and the rotation angle information obtained by the rotation angle calculation means indicates the wafer linear portion. When the exposure is started, the radial displacing means is driven to position the light irradiating means with respect to the linear portion of the wafer while the rotating means is stopped, and then the tangential displacing means is driven. And a control means for relatively linearly displacing the light irradiation means along the straight line portion of the wafer.

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

(A) As the radial displacement means, the light irradiation means may be displaced with respect to the rotation means, or the rotation means may be displaced 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.

Further, in the invention described in claim 2, the rotating means for rotating the wafer, the peripheral portion of which is composed of the circular arc portion and the linear portion, the light irradiation means for exposing the peripheral portion of the wafer, and the wafer linear portion are detected. A linear portion detecting line sensor, a rotation angle calculating means for obtaining the current rotation angle information of the wafer based on the detection of the wafer linear portion by the linear portion detecting line sensor, and the light irradiation means for rotating the rotating means. 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 the change point of the exposure width set by the exposure width setting means, the exposure width corresponding to the rotation angle at that time is read out from the exposure width setting means, and the exposure width is changed for each angle. To It is characterized in that a control means for adjusting the position relative to the wafer peripheral portion of the light emitting means to drive said radial displacement means.

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

(D) The radial displacement means may be one that displaces the light irradiation means with respect to the rotation means, or one that displaces 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.

According to a third aspect of the present invention, the rotating means for rotating the wafer, the peripheral portion of which is an arc portion and the linear portion, the light irradiation means for exposing the peripheral portion of the wafer, and the wafer linear portion are detected. A linear portion detecting line sensor, a rotation angle calculating means for obtaining the current rotation angle information of the wafer based on the detection of the wafer linear portion by the linear portion detecting line sensor, and the light irradiation means for rotating the rotating means. 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 the 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.

Also in this configuration, the notes (d) and (e) to the configuration of the invention described in claim 2 can be mentioned.

[0022]

The operation of the invention described in claim 1 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 the change point of the exposure width set by the exposure width setting means, the exposure width setting means The exposure width corresponding to the rotation angle at that time is read out, and the radial displacement means is driven to adjust the position of the light irradiation means relative to the wafer peripheral portion for each angle of the change point of the exposure width. Further, it is possible to change the exposure width.

According to the third aspect of the invention, the rotation angle is monitored, and when the monitored rotation angle reaches the change point of the exposure width set by the exposure width setting means, the rotation means of the rotation means is changed. The driving is stopped, 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 the position of the light irradiation means with respect to the peripheral portion of the wafer is adjusted. Since the driving of the means is restarted, it is possible to change the exposure width for each rotation angle.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION 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.

The rotation shaft of the spin chuck 1 for holding the wafer W by suction and rotating it horizontally is connected to the 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 ray transmitting filter 4, a shutter 5 and the like, and the ultraviolet ray passing through the filter 4 is guided by an optical fiber 6 to its irradiation end 6a. 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, when the ultraviolet spot is circular, the spot of the spot in the radial direction of the wafer is measured with respect to the center of the spot. At both end positions (positions near and far from the center of the wafer in the circular spot), the integrated light intensity decreases, so exposure and eventually resist removal may become uneven. It is preferable to make the above uniform.

A fiber support arm 7 for holding the irradiation end 6a at the tip of the optical fiber 6 is attached to the 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 the radial displacement means Mx in the constitution of the invention, and the Y table 8y and the third motor M3 constitute the tangential displacement means My in the constitution of the invention. I am configuring.

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 that is attracted to and held by the spin chuck 1 and is rotated is arranged corresponding to the rotation locus of the peripheral portion of the wafer W. ing.

FIG. 2 shows another form of the mechanical structure of the wafer peripheral exposure apparatus, which shows two uniaxial tables 10x,
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. Further, the uniaxial table 10y is attached with the first motor M1 as the rotating means Mθ and the spin chuck 1, and is reciprocated in the Y direction by the third motor M3.

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

Instead of the structure of FIGS. 1 and 2, the radial displacement means Mx may be configured to displace the rotation means Mθ (first motor M1 and 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 description will be given of the detection of 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.

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 wafer W is driven by driving the first motor M1.
When is rotated, the number of ON cells among the cells of the line sensor 9 is constant in a state where the arc portion Wc is passing over the line sensor 9. From that state, the number of cells in which the line sensor 9 is turned ON increases at the moment when one wafer edge portion We, which is the boundary between the straight 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 is further rotated, O is kept until the center of the straight line portion Ws reaches the line sensor 9.
The number of N cells continues to increase, and after passing 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 incorporates a 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 the reference angle α at the center of the straight line portion Ws is calculated in this way, the wafer W is rotated once again and the motor M1 is stopped when the number of pulses corresponding to the reference angle α is detected. Will stop in a state where the straight line 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 linear portion Ws of the wafer.

Wafer W in a state where 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 Exposure Device> In the block diagram of FIG. 3, A is a linear part detecting line sensor corresponding to the above-mentioned line sensor 9, and B is a linear part detecting line sensor A. The rotation angle calculation means, C, for detecting the wafer linear portion Ws, and for obtaining the reference angle α of the wafer W and the current rotation angle information θt that changes from moment to moment on the basis of the output of the pulse encoder in the rotation means Mθ,
It is an exposure width setting unit that sets the arc-shaped exposure width Lc and the linear-part exposure width Ls independently of each other.

Mθ is a rotating means of 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,
It is a control means for controlling the light irradiation means Mv, the radial displacement means Mx, and the tangential displacement means My.

Wafer W transferred to 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 this 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).

Then, the preparatory operation for the exposure of the linear portion is started. 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.
Position with respect to s. 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 the irradiation of the 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 displaced along the wafer linear portion Ws to linearly set the linear portion exposure width Ls by the ultraviolet rays from the optical fiber irradiation end 6a.
The exposure is carried out uniformly in step (see FIG. 4 (d)). 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 preparatory operation for exposing the arc portion is started. 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 rays from the optical fiber irradiation end 6a, and drives the rotating means Mθ to expose the wafer W to the light irradiation means Mv. The wafer arc Wc is rotated and is uniformly exposed in the arc exposure width Lc by the ultraviolet rays from the optical fiber irradiation end 6a (FIG. 4).
(See (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 straight portion Ws is exposed with a uniform exposure width over the entire length of the straight portion Ws. The exposure is performed with an exposure width Ls independent of the exposure width Lc of the wafer arc Wc.

In this operation example, the control means E performs the exposure of the straight line portion Ws first and the exposure of the circular arc portion Wc later, but on the contrary, the control means E first exposes the circular arc portion Wc. Straight part W
The exposure of s may be performed later.

The exposure width Lc of the arc portion and the exposure width L of the straight portion
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, the configuration is basically the same as that of 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 wafer W is adjusted in position.

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)).

The control means E, after calculating the reference angle α,
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 to start the irradiation of ultraviolet rays from the optical fiber irradiation end 6a, and drives the rotating means Mθ to rotate the wafer W and rotate the wafer W arc portion Wc. Is exposed (Fig. 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 wafer M by driving the rotating means Mθ, the circular arc portion Wc is exposed with a new exposure width L (θ _t1 ). Then, 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 the radius is calculated 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).

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

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

When the wafer straight portion Ws is exposed, the exposure width is finely and stepwise adjusted by the exposure width L (θ _ti ) for each rotation angle θt _i . 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, when the wafer edge We is detected, the wafer linear portion Ws is made parallel to the Y direction as shown in FIG. 4B, and the tangential displacement means My is driven to linearly move the light irradiation means Mv. The portion Ws may be exposed.

As another method, the wafer W is rotated twice, and the thin exposure width L (θ _t0 ) is fixed as a constant exposure width in the first rotation, and the exposure is continuously performed by making one rotation 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 matches.
In another angle range, the shutter 5 may be closed.

[0068]

As is apparent from the above description, according to the invention described in claim 1, the position adjustment of the light irradiation means with respect to the wafer arc portion is performed according to the set exposure width according to the current rotation angle. By setting the exposure width at the angular position grasped by the clamp claws in a later step to be larger than that at other angular positions, the clamp area can be exposed with a width larger than other areas. 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 large, it is possible to expose only that region with a wide width, and therefore the entire thick film region can be exposed.

Also in the inventions described in claims 2 and 3, similarly to the above-mentioned claim 1, when the clamp region is exposed with a larger width than other regions or when the thick film region is wide, only that region is wide. The width can be used for exposure, contamination of the wafer and the device can be prevented, and the entire thick film region can be exposed.

Further, in the invention described in claim 1, 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. Therefore, it is also possible to perform exposure with the same exposure width over the entire length of the linear portion.

[Brief description of 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 form of a wafer peripheral exposure apparatus.

FIG. 3 is a block configuration 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 operation explanatory diagram of a peripheral exposure apparatus for a second wafer.

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 problem of the related art.

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Go Takada, 322 Hazashishi Furukawa-cho, Fushimi-ku, Kyoto City Dainichi Hon screen manufacturing Co., Ltd. Rakusai Plant Dainichi Main Screen Manufacturing Co., Ltd. Rakusai Plant

Claims (3)

[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, the peripheral portion of which is composed of an arc portion and a linear portion, a light irradiation means for exposing the peripheral portion of the wafer, and a linear portion detecting line sensor for detecting the linear portion of the wafer. Rotation angle calculation means for obtaining current wafer rotation angle information based on the detection of the wafer straight line portion by the straight line portion detection line sensor, and the light irradiation means relatively approaching and separating from the rotation center of the rotation means. Radial displacement means, an exposure width setting means for setting an exposure width according to a rotation angle, a rotation angle calculated by the rotation angle calculation means, and the monitored rotation angle is adjusted by the exposure width setting means. When the set change point of the exposure width is reached, the exposure width according to the rotation angle at that time is read from the exposure width setting means, and the radial displacement means is driven at each angle of the change point of the exposure width. And a control means for moving the light irradiation means to adjust the position of the light irradiation means with respect to the peripheral portion of the wafer. 3. A rotating means for rotating a wafer whose peripheral portion is composed of an arc portion and a linear portion, a light irradiation means for exposing the peripheral portion of the wafer, and a linear portion detecting line sensor for detecting the linear portion of the wafer. Rotation angle calculation means for obtaining current wafer rotation angle information based on the detection of the wafer straight line portion by the straight line portion detection line sensor, and the light irradiation means relatively approaching and separating from the rotation center of the rotation means. Radial displacement means, an exposure width setting means for setting an exposure width according to a rotation angle, a rotation angle calculated by the rotation angle calculation means, and the monitored rotation angle is adjusted by the exposure width setting means. When the set change point of the exposure width is reached, the drive 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.