JPH10308350A - Device and method for exposing periphery and method for manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate for deterioration of resist sensitivity due to side rinsing without increasing a gray zone. SOLUTION: A device for exposing periphery irradiates a part of a peripheral part of a resist-applied wafer 1, having an almost circular form, with exposure light in a form of a specified irradiation region 18, and by relatively rotating a wafer around its center axis under the condition, the resist of the peripheral part of the wafer is exposed in annular manner. In this case, the form of the irradiation region has a side almost along the inner side of the annular form, and also has a form in which the quantity of the exposure light increases from the side toward the center of the annular form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peripheral exposure apparatus and method for performing exposure for removing unnecessary resist around an electronic material such as a semiconductor wafer to which a photosensitive resist is mainly applied, and a device manufacturing using the same. About the method.

[0002]

2. Description of the Related Art Conventionally, in a technique of this type, for example, a technique for forming a circuit pattern on a semiconductor wafer, when a photosensitive resist film is formed on a wafer, a spin coating method generally called a spin coating method is used. In the spin coating method, a wafer is placed on a turntable, a resist is poured near the center of the wafer and rotated, and the resist is applied to the entire surface of the wafer by centrifugal force.

[0003] However, according to the spin coating method, the resist may protrude from the peripheral portion of the wafer and may reach the back side. Unnecessary resist that has wrapped around the wafer periphery and the back surface, if left as it is, will be lost if a mechanical shock such as grabbing or rubbing the wafer for transport during the process is applied, and dust will be lost. This may have an adverse effect, and lower the yield in manufacturing semiconductor devices, which is a major problem.

[0004] Therefore, as a method of removing such an unnecessary portion of the resist, a solvent jetting method (back rinsing method) is used.
Is used. In this method, a solvent is jetted from the back surface of the wafer to which the resist is attached, thereby dissolving unnecessary resist on the back surface of the wafer. Further, it is necessary to remove the resist in the peripheral portion of the wafer. As a method of removing the resist in the peripheral portion of the wafer, as shown in FIG. A so-called “peripheral exposure method” in which a resist is exposed to light and then developed and removed is known. In the example of FIG. 8A, the shape of a portion irradiated with UV light on the wafer is circular.

In Japanese Patent Application Laid-Open No. 1-112037, FIG.
As shown in (b), the shape of the portion irradiated with UV light is rectangular 3
Is disclosed. The effect of making the irradiation area rectangular 3 is described in detail in Japanese Patent Application Laid-Open No. 1-112037, and the description is omitted here.

[0006]

In recent years, the improvement of the solvent jetting method has been remarkably advanced. In addition to the removal of the resist wrapping around the back surface of the wafer (back rinsing method), the resist at the peripheral portion of the wafer is also removed by the solvent jetting method (side rinsing). (A rinsing method), and the resist is removed again by irradiating with UV light over a wide area of the wafer irradiation portion. This is because dust also poses a problem when transporting a resist-coated wafer in a coater developer, and it is necessary to remove the resist around the wafer by solvent spraying (side rinsing) after spin-coating the resist. This is because it has become general.

FIG. 9A is a cross-sectional view of a wafer immediately after a surface is coated with a resist. In the figure, reference numeral 4 denotes a coated resist, and 4b denotes a portion to be removed by a back rinsing method. Further, as shown in FIGS. 9A and 9B, the portion 4c is removed by the side rinse method. FIG.
(B) shows the state of application of the resist 4 on the wafer 1 after performing the back rinsing method and the side rinsing method.
Further, 4f and 4f in FIG.
The portion e is removed. In this way, 4a of FIG.
Is removed by a side rinse method and a peripheral exposure method. FIG. 10 corresponds to FIG.
FIG. 3B shows a state in which the wafer 1 in the state of FIG.

However, the side rinsing method has a problem that the amount of the solvent jetted becomes small, for example, when the amount of the remaining solvent becomes small, and the resist mark 4d remains without being completely melted as shown in FIG. Furthermore, in the side rinsing method, the resist boundary portion 4f to be removed shown in FIG. 9B has a width of about several hundred μm to 1000 μm, and this causes a region generally called a gray zone. It is known that the resist in the gray zone 4f is easily peeled off when developing after exposing a circuit pattern to a pattern forming portion with a stepper, and goes around the circuit pattern portion to cause a pattern defect. . For this reason, before transferring the circuit pattern on the stepper, the peripheral exposure device provided in the stepper irradiates light to the area of the wafer peripheral portion 4a in FIG. It is necessary to remove the remaining resist portion 4e including the gray zone 4f generated by the rinsing method and the resist trace 4d shown in FIG. The resist boundary removed by the peripheral exposure method has a width of several tens μm, which is much narrower than the gray zone 4f generated by the solvent injection method.
A gray zone 4g of up to about m is generated, but with such a width, there is no peeling during development, and the problem of pattern defects does not occur.

However, the resist exposed to the solvent by the side rinse method causes a reduction in sensitivity, and the removal of the resist by the peripheral exposure method requires about 20% more exposure than the case where no solvent is applied. Was found by our experiments. When the peripheral exposure is performed with the same exposure amount as in the case of removing without performing the side rinsing method, although the resist of the portion 4e is removed, the resist trace 4d and the gray zone 4f remain without being completely removed. Such a resist that cannot be completely removed and remains in an isolated state is extremely likely to become dust, which is a problem because it easily causes pattern defects. In order to remove the resist trace 4d and the gray zone 4f by increasing the exposure amount, it is conceivable to reduce the rotation of the wafer during peripheral exposure and increase the integrated exposure amount. However, in this method, 20%, which is a decrease in the sensitivity of the resist, directly leads to an increase in the time for the peripheral exposure, which causes a problem in throughput.

A method of enlarging the UV light irradiation area in the rotation direction of the wafer is conceivable. However, this method has a problem that a gray zone at the time of peripheral exposure is increased. In other words, when the irradiation area is rectangular, the rectangular irradiation area 14 moves around the wafer circumference to expose at the boundary of the resist to be removed, as shown in FIG. Is lower than the integrated exposure amount at the center of the rectangular irradiation area 14 to generate a gray zone (inner ring difference of the integrated exposure amount).

Further, the Hg lamp used for the peripheral exposure is usually replaced after being used for about one month because the illuminance is reduced by about 30%. Solvent injection method (side rinse) and U
When the resist removal by V light irradiation is also used, the Hg lamp needs to be replaced as soon as the above-mentioned decrease in the sensitivity of the resist, which poses a serious problem in running cost.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to compensate for a decrease in resist sensitivity due to a side rinse method without increasing a gray zone (inner ring difference of integrated exposure amount) during peripheral exposure. An object of the present invention is to increase an integrated exposure amount of peripheral exposure.

[0013]

In order to achieve this object, according to the present invention, a part of a peripheral portion of a wafer having a substantially circular shape coated with a resist is irradiated with exposure light in a predetermined irradiation region shape. In this state, in the peripheral exposure apparatus or the method for circularly exposing the resist at the peripheral portion of the wafer by relatively rotating the wafer around its central axis, the shape of the irradiation area is set inside the circular shape. It has one side (edge 16 or the like) substantially along the side and the center of the annular shape (central portion 17) from the side.
, Etc.). The device manufacturing method of the present invention is characterized in that peripheral exposure is performed by such a peripheral exposure method.

According to this, since the exposure amount (integrated exposure amount) exposed at the center of the annular shape is larger than the exposure amount inside the annular shape, the sensitivity existing near the center of the annular shape decreases. In addition to providing a sufficient exposure amount to the resist traces that have been made, since it is not necessary to unnecessarily lengthen the one side near the inside of the annular shape,
It does not increase the gray zone. That is, it is possible to efficiently expose and remove the resist and the trace of the resist in the gray zone caused by the side rinse. Therefore, generation of pattern defects due to resist dust is efficiently suppressed, and efficient device manufacture is performed.

[0015]

In a preferred embodiment of the present invention, the shape of the irradiation region is a tall shape having a bottom side as the one side, a trapezoidal shape having an upper base as the one side, Alternatively, it is a fan-shaped shape having substantially the same curvature as the annular shape. In any case, it is preferable that the one side is curved with substantially the same curvature and the same direction as the inner side of the annular shape. This is because the gray zone can be reduced.

A field stop for shaping the exposure light into a shape of the predetermined irradiation area; and the field stop has a plurality of irradiation shapes having different curvatures depending on the size of the wafer. There are a plurality of things that create an area. By arranging these stops in a turret shape and switching and using the optimum one according to the wafer size, it is possible to perform peripheral exposure on various wafers quickly and efficiently.

[0017] The length of a portion of the irradiation region along the annular shape at the center of the annular shape is 1.2 times or more that of the inside of the annular shape. According to this, since the exposure amount (integrated exposure amount) at the center of the annular shape becomes 1.2 times or more that of the inside of the annular shape, the resist and the trace of the resist in the gray zone portion caused by the side rinse are formed. Both the portion with reduced resist sensitivity and the resist-free resist portion used for side rinsing can be efficiently exposed and removed with a necessary and sufficient exposure amount.

[0018]

FIG. 1 is a schematic sectional view showing an exposure apparatus according to one embodiment of the present invention. In the figure, 61 is a lamp as a light source,
62 is an elliptical mirror, 63 is a plane mirror, 64 is a shutter, 65 is a filter, 6 is the lamp 61, elliptical mirror 62, plane mirror 63, shutter 64 and filter 65
, A light-receiving side fitting for connecting the light guide fiber 8 to the lamp box 6, an optical fiber bundle 9 constituting the light guide fiber 8, and a flexible tube 10 covering the optical fiber bundle 9. is there. Light from the lamp 61 disposed at the first focal point of the elliptical mirror 62 is condensed by the elliptical mirror 62, reflected by the plane mirror 63, and
Reach Then, when the shutter 64 is released, only the light of a desired wavelength out of the irradiation light of the lamp 61 is transmitted by the filter 65, and the light is incident on the incident portion 8 a of the light guide fiber 8 which is the second focal point of the elliptical mirror 62. Form an image. The light incident on the incident end 8a of the fiber 8 is guided by the fiber 8 and exits from the exit end 8b. Fiber output end 8
The light emitted from the lens b irradiates the aperture 15, and a part of the light flux passing through the aperture 15 is converted by the lens unit 12 into the wafer 1.
Focus on top.

FIG. 2 is a diagram showing details of the UV irradiating section including the light guide fiber 8, the diaphragm 15 and the lens unit 12 and the wafer 1 in FIG. FIG. 2A is a cross-sectional view as viewed from a direction perpendicular to the traveling direction of light rays.
(B) is a cross-sectional view of the fiber exit end 8b viewed from the stop 15 side. The position of the stop 15 is conjugate with the surface of the wafer 1 via the lens unit 12. That is, FIG.
The shape of the diaphragm 15 shown in FIG. 2B is imaged on the wafer 1 by the lens unit 12. At this time, the light beam emitted from the fiber end 8b irradiates the entire surface of the stop 15, and a part of the light beam passes through the stop 15 in a form. By the lens unit 12, the shape of the aperture 15 becomes the shape of the light beam irradiation area 18 on the wafer 1.

The feature of this embodiment lies in that the diaphragm 15 on the side of the fiber emission end 8b is barrel-shaped. By making the diaphragm 15 barrel-shaped, the integrated exposure amount at the central portion of the irradiation area 18 on the wafer 1 becomes larger than the integrated exposure amount at the edge portion. Thereby, a sufficient exposure amount for removing the resist residue after the side rinse is obtained. Hereinafter, the barrel shape of the aperture 15 will be described in detail.

FIG. 3C shows the shape of a rectangular aperture 14 conventionally used. Usually, since the outer diameter of the lens unit 12 is a circle, a circular range indicated by a dotted line is an irradiation area 13 where an image is favorably formed without being blurred.
In order to maximize the integrated exposure, a rectangular aperture 1
4 is usually arranged so as to be inscribed in the irradiation area 13 without vignetting.

On the other hand, FIG. 3A shows the relationship between the barrel stop 15 and the irradiation area 13 without vignetting in this embodiment.
By making the circumference of the opening of the barrel-shaped aperture 15 coincide with the circumference of the irradiation area 13, the barrel-shaped aperture 15 is maximized within an image forming range that is not shaken by the lens unit 12. By adopting this shape, the integrated exposure amount by the central portion 17 indicated by the double-ended arrow is made larger than the integrated exposure amount by the edge portion 16 indicated by the double-ended arrow in FIG. It is possible to set a large value most efficiently without any problem.

At this time, the length of the edge 16 and the center 1
The relationship of the length of 7 is such that the length of the central portion 17 ≧ 1.2 × (the edge portion) in order to compensate for the sensitivity decrease (20% reduction) of the side rinse portion existing in the wafer portion where the integrated exposure is performed at the central portion 17 1
6 length). Note that, as shown in FIG. 3B, the opening of the barrel-shaped diaphragm 15 does not always need to be configured to coincide with the circumference of the irradiation area 13. Also in this case, the barrel-shaped diaphragm 15 is characterized by (length of the center portion 17) ≧ 1.2 × (length of the edge portion 16).

As shown in FIG. 4A, the image of the barrel stop 15 is projected onto the wafer 1 by the lens unit 12 so that the exposure area 1
8 is formed. In the figure, reference numeral 1c denotes a region from which the resist has been removed by side rinsing, and 1d denotes a resist mark generated during side rinsing. The barrel-shaped center of the exposure area 18 where the integrated exposure amount becomes the largest is the resist mark 1
The peripheral exposure is performed by aligning the relative position between the exposure area 18 and the wafer 1 so as to be located at d. Reference numeral 1b denotes an area to be exposed and removed by the exposure area 18.

FIG. 4B shows the relative position between the peripheral exposure region 18 and the wafer 1 when the peripheral exposure width is changed by the process. In this case, as shown in FIG. 4B, an arbitrary exposure width can be set by disposing the exposure region 18 outside the wafer 1 as compared with the case of FIG. 4A. At this time, the position of the UV irradiation unit may be shifted and rearranged, but usually, when performing the peripheral exposure,
Since the wafer 1 moves in the horizontal direction (xy directions) and is mounted on a rotating stage, by controlling the rotation center axis of the wafer to a position where the exposure width is changed,
It is assumed that the wafer 1 is arranged inside the exposure area 18. Thus, there is an advantage that the position of the irradiation area (exposure area) on the wafer can be adjusted without adding a device for adjusting the position of the UV irradiation unit. Also, an arbitrary exposure width can be obtained.

FIG. 5A shows a diaphragm 19 according to another embodiment of the present invention. When exposing the peripheral portion of the wafer with the conventional rectangular aperture 14 shown in FIG. 5B, the wafer is rotated to expose the peripheral portion of the wafer. 5 (b) is shown by the one-dot chain line 21, and the edge end is shown by the two-dot chain line 22. The width 20 of the trajectories 21 and 22 contributes to the enlargement of the gray zone when peripheral exposure is performed (the inner ring difference of the integrated exposure amount). On the other hand, according to the stop 19, the edge indicated by the dotted line 23 closer to the rotation center of the stop is formed into a concave edge shape 24 in conformity with the circumference of the wafer. The trajectory 25 indicated by the dashed line coincides with the center of the edge portion 24 at the end, and the width 20 of the trajectory as shown in FIG. 5B is eliminated, so that the gray zone performance can be improved.
The diameter of the concave edge portion 24 of the diaphragm 19 may be such that the diameter when projected onto the wafer 1 by the lens unit 12 is substantially equal to the outer diameter of the wafer 1 on which peripheral exposure is performed.

Further, depending on the wafer size, the edge portion 24
Of the wafer used is 5 ", 6",
A plurality of apertures corresponding to sizes such as 8 "and 12" are formed in a turret shape at the position of the aperture 15 shown in FIG.
The turret may be rotated according to the wafer size, and an optimal aperture may be used according to the wafer size. According to this, since it can correspond to all wafer sizes,
Since there is no need to change the aperture, space saving of the apparatus and improvement in throughput can be expected.

If there is room in the image forming range of the projection lens 12, a trapezoidal diaphragm 26 as shown in FIG. 6A may be used. At this time, the relationship between the length of the edge portion 27 and the length of the center portion 28 is (length of the center portion 28) ≧ 1.2 × (length of the edge portion 27).

Further, as shown in FIG. 6B, a fan-shaped aperture 29 may be used. At this time, the relationship between the arc length of the edge portion 30 and the arc length of the center portion 31 is (center portion 31
Length) ≧ 1.2 × (length of the edge portion 30).

The trapezoidal diaphragm 26 and the fan-shaped diaphragm 2 as described above
According to No. 9, since the integrated exposure amount at the time of performing the peripheral exposure increases from the wafer center side (the edge portions 27 and 30 sides) toward the outside of the wafer, the resist remaining after the side rinse is further removed. A sufficient integrated exposure amount can be obtained. Further, according to the sector stop 29, it can be expected to reduce the gray zone.

In the present invention, the apertures 15, 19, 2
The end face shape of the fiber emitting portion 8b for irradiating 6, 29 is
It can be round or rectangular. However, for the shapes of the apertures 15 and 19, the fiber exit 8
b, the shape of the end face is circular, and for the shapes of the diaphragms 26 and 29, the shape of the end face of the fiber emitting portion 8b is rectangular.
The shape of the end face of the fiber emitting section 8b is reduced by apertures 15, 19,
It is more preferable to adopt a shape close to each of the shapes 6 and 29 since the energy efficiency of transmission on the wafer 1 is improved. At this time, if the end face shape of each of the fiber incident ends 8a is circular, the light beam condensing state at the second light condensing position of the elliptical mirror 62 is closer to a circle, so that the energy efficiency transmitted to the wafer 1 is better. Become more desirable. Further, as shown in FIG.
May be arranged closely, or may be slightly opened as shown in FIG.

In the conventional example shown in Japanese Patent Application Laid-Open No. 1-112037, as shown in FIG. 11A, the shape of the fiber emitting end 8b itself is formed into a rectangular shape, and the fiber emitting end 8b is formed by the lens unit 12 without passing through a stop. , Fiber emission end 8b
Is formed on the wafer 1. But,
When the fiber output end 8b is formed in a rectangular shape, it is difficult to align the optical fiber bundle 9 therein, and the rectangular end portion 33 is formed.
In particular, the arrangement of the optical fiber bundle 9 is disturbed. The disorder of the arrangement of the optical fiber bundles 9 at the end 33 is not preferable because it leads to a decrease in the integrated exposure amount at the time of peripheral exposure and deteriorates the gray zone 4g shown in FIG. 9C. Therefore, as shown in FIG. 11B, when the fiber exit end 8b and the stop 15 are brought into close contact with each other, the opening of the stop 15 is set within a range where the optical fiber bundles 9 in the fiber exit end 8b are aligned. Need to be located. Since the arrangement disorder of the optical fiber bundle 9 is likely to occur in the outer one row, the shape of the opening of the diaphragm 15 is set to be smaller than that of the rectangular area 90 where the optical fiber bundle 9 of the fiber end 8b is closely arranged. It is necessary to reduce the size of the bundle 9 by at least the width of one fiber to reduce the influence of disturbance.

For this purpose, the light exiting from the rectangular area 90 where the optical fiber bundles 9 are arranged as shown in FIG. It is possible to illuminate a range larger than one fiber bundle by the size of the portion, and it is possible to reduce the influence of the arrangement disorder at the rectangular end 33 shown in FIG.

Further, as shown in FIG. 7, a configuration may be adopted in which a lens 32 is provided between the fiber exit end 8b and the stop 15 to perform illumination. In this case, the fiber emission end 8b is located at the focal position on the fiber emission end side of the lens 32,
The aperture 15 may be Koehler-illuminated by the lens 32. By using Koehler illumination, the fiber end 8b
Since the image of the optical fiber bundle 9 does not form an image on the stop 15, it is possible to eliminate the influence of the disorder of the arrangement at the rectangular end shown in FIG.

Next, a description will be given of an example of manufacturing a device that can use this exposure apparatus. FIG. 12 shows a micro device (a semiconductor chip such as an IC or an LSI, a liquid crystal panel, a CC)
D, thin-film magnetic head, micromachine, etc.). In step 31 (circuit design), the circuit of the semiconductor device is designed. Step 32 is a process for making a mask on the basis of the circuit pattern design.
On the other hand, in step 33 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 34 (wafer process) is referred to as a preprocess, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 35 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer prepared in step 34, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). including. In step 36 (inspection), inspections such as an operation check test and a durability test of the semiconductor device manufactured in step 35 are performed. Through these steps, a semiconductor device is completed and shipped (step 37).

FIG. 13 shows a detailed flow of the wafer process. Step 41 (oxidation) oxidizes the wafer's surface. In step 42 (CVD), an insulating film is formed on the wafer surface. In step 43 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 44 (ion implantation), ions are implanted into the wafer. Step 4
In 5 (resist processing), a photosensitive agent is applied to the wafer. Step 46 (exposure) uses the above-described exposure apparatus to print and expose the circuit pattern of the mask onto the wafer. In step 47 (developing), the exposed wafer is developed. In step 48 (etching), portions other than the developed resist image are removed. In step 49 (resist removal),
After the etching, the unnecessary resist is removed.
By repeating these steps, multiple circuit patterns are formed on the wafer. By using the manufacturing method of the present embodiment, a highly integrated semiconductor device, which has conventionally been difficult to manufacture, can be manufactured at low cost.

[0037]

As described above, according to the present invention,
The shape of the irradiation area (exposure area) of the exposure light has one side substantially along the inner side of the annular shape as the portion to be exposed, and the exposure amount from the side toward the center of the annular shape is reduced. Since the shape is increased, the resist and the trace of the resist in the gray zone caused by the side rinse can be efficiently exposed and removed.

Further, since the one side has a shape curved substantially in the same direction and in the same direction as the inside side of the annular shape, the gray zone can be reduced. Further, as a field stop for shaping the exposure light into the shape of the predetermined irradiation area, a plurality of apertures that generate the irradiation areas having a plurality of shapes having different curvatures on one side according to the size of a wafer are used. With the provision, peripheral exposure can be performed quickly and efficiently on various wafers.

Further, the length of a portion of the irradiation area along the annular shape at the center of the annular shape is 1.2 times or more that of the inside of the annular shape. Both the resist and the portion of the resist trace with reduced resist sensitivity and the resist-free resist portion used for side rinsing can be efficiently exposed and removed with a necessary and sufficient exposure amount.

Further, since peripheral exposure is performed by such a peripheral exposure method, generation of pattern defects due to resist dust can be efficiently suppressed, and efficient device manufacture can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an exposure apparatus according to one embodiment of the present invention.

FIG. 2 is a detailed view of a part of FIG.

FIG. 3 is a diagram showing the shape of the stop in FIG. 1 in comparison with a conventional example.

FIG. 4 is a diagram showing a positional relationship between a peripheral exposure area (irradiation area) and a wafer in the apparatus of FIG.

FIG. 5 is a diagram showing another example of a diaphragm that can be used in the apparatus of FIG. 1 in comparison with a conventional example.

FIG. 6 is a view showing still another example of a diaphragm that can be used in the apparatus of FIG. 1;

FIG. 7 is a diagram showing a modification of the apparatus of FIG. 1;

FIG. 8 is a diagram showing a peripheral exposure method according to a conventional example.

FIG. 9 is a cross-sectional view showing how the resist around the wafer is removed.

FIG. 10 is a plan view showing a state in which a resist around a wafer is removed.

FIG. 11 is a diagram showing a fiber emission end of the apparatus of FIG. 1;

FIG. 12 is a flowchart showing a flow of manufacturing a micro device that can be manufactured by the apparatus of FIG. 1;

FIG. 13 is a flowchart showing a detailed flow of a wafer process in FIG. 12;

[Explanation of symbols]

1: wafer, 2, 3, 18: exposure area (irradiation area),
4: resist, 6: lamp house, 61: Hg lamp,
62: elliptical mirror, 63: plane mirror, 64: shutter, 65: filter, 8: fiber, 9: fiber bundle, 12: lens unit, 13: irradiation area without vignetting, 14, 15, 19, 26, 29 : Aperture, 16, 2
4, 27, 30: edge portion, 17, 28, 31: central portion, 20: inner ring difference of integrated exposure amount.

Claims (15)

[Claims] 1. A part of a peripheral portion of a wafer having a substantially circular shape coated with a resist is irradiated with exposure light in a predetermined irradiation region shape, and in this state, the wafer is relatively moved around its central axis. In the peripheral exposure apparatus for circularly exposing the resist in the peripheral portion of the wafer by rotating the peripheral region, the shape of the irradiation region has one side substantially along the inner side of the annular shape, and from the side, A peripheral exposure apparatus having a shape in which the amount of exposure increases toward the center of the annular shape. 2. The peripheral exposure apparatus according to claim 1, wherein the shape of the irradiation area is a tall shape having a bottom side as the one side. 3. The peripheral exposure apparatus according to claim 1, wherein the shape of the irradiation area is a trapezoidal shape having an upper base as the one side. 4. The peripheral exposure apparatus according to claim 1, wherein the shape of the irradiation area is a sector shape, and the curvature is substantially the same as the curvature of the annular shape. 5. The method according to claim 1, wherein the one side is curved with substantially the same curvature and the same direction as the inner side of the annular shape. Peripheral exposure device. 6. A field stop for shaping the exposure light into a shape of the predetermined irradiation area, and as the field stop, a plurality of irradiation shapes having different curvatures depending on the size of the wafer. 6. The peripheral exposure apparatus according to claim 5, further comprising a plurality of devices for generating an area. 7. The device according to claim 1, wherein a length of a portion along the annular shape of the irradiation area at a center of the annular shape is 1.2 times or more as long as that inside the annular shape. The peripheral exposure apparatus according to any one of claims 1 to 6. 8. A portion of a peripheral portion of a resist-applied wafer having a substantially circular shape is irradiated with exposure light in a predetermined irradiation area shape, and in this state, the wafer is relatively moved around its central axis. In the peripheral exposure method of circularly exposing the resist at the peripheral portion of the wafer by rotating the peripheral region, the shape of the irradiation area has one side substantially along the inner side of the circular shape, and A peripheral exposure method, wherein the shape is such that the amount of exposure increases toward the center of the annular shape. 9. The peripheral exposure method according to claim 8, wherein the shape of the irradiation area is a tall shape having a bottom side as the one side. 10. The shape of the irradiation area is such that the upper bottom is
9. The peripheral exposure method according to claim 8, wherein the edge exposure method has a trapezoidal shape having two sides. 11. The peripheral exposure method according to claim 8, wherein the shape of the irradiation area is a sector shape, and the curvature thereof is substantially the same as the curvature of the annular shape. 12. The method according to claim 8, wherein the one side is curved with substantially the same curvature and the same direction as the inner side of the annular shape. Perimeter exposure method. 13. A field stop for shaping the exposure light into a shape of the predetermined irradiation area, wherein the field stop has a plurality of shapes having the different curvatures depending on the size of the wafer. 13. The peripheral exposure method according to claim 12, comprising a plurality of elements for generating an area. 14. The apparatus according to claim 8, wherein a length of a portion along the annular shape of the irradiation region at the center of the annular shape is 1.2 times or more as large as that inside the annular shape. 14. The peripheral exposure method according to any one of items 13 to 13. 15. A device manufacturing method, wherein peripheral exposure is performed by the method according to claim 8.