JPH08335545A - Exposing method and apparatus - Google Patents

Abstract

PURPOSE: To improve throughput by exposing the periphery of an object to be processed after executing the prealignment to the object on a rotary stage and then executing pattern exposure, on the exposing stage, to the periphery of object having completed prealignment and exposure. CONSTITUTION: A semiconductor wafer 3 as an object to be processed is plated on a rotary stage 7 and such semiconductor wafer 3 is pre-aligned. Thereafter, the semiconductor wafer 3 is irradiated, for the purpose of peripheral exposure, with a light beam 2 on the rotary stage 7 through a second optical system 10 having a light control means. The semiconductor wafer 3 having completed the prealignment and peripheral exposure is irradiated with a light beam 2 on an exposure stage 4 with a first optical system 6 for the purpose of pattern exposure. Thereby, throughput of the exposure process of semiconductor wafer 3 can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure technique for an object to be processed such as a semiconductor wafer, and more particularly to an exposure method and apparatus for performing peripheral exposure after prealignment of the object to be processed on a rotary stage for prealignment. .

[0002]

2. Description of the Related Art The techniques described below are for studying the present invention,
The present invention was studied by the present inventors upon completion, and its outline is as follows.

In the exposure technique of a semiconductor wafer which is an example of an object to be processed, peripheral exposure of the semiconductor wafer is required in most photolithography processes.

Here, separate apparatuses are used for an exposure apparatus for performing pattern exposure on a semiconductor wafer and a peripheral exposure apparatus for performing peripheral exposure. After performing pattern exposure by the exposure apparatus, peripheral exposure is performed by the peripheral exposure apparatus. Is going.

An exposure apparatus for semiconductor wafers is described in, for example, Japanese Patent Laid-Open No. 60-186843.

[0006]

However, in the above-mentioned technique, since the peripheral exposure is performed by another apparatus (peripheral exposure apparatus) after the pattern exposure, the throughput in the exposure processing of the semiconductor wafer cannot be improved. It is said that

Further, the peripheral exposure apparatus has a problem that its function is expensive.

Therefore, an object of the present invention is to provide an exposure method and apparatus for improving the throughput in the exposure processing of an object to be processed.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, in the exposure method of the present invention, after pre-aligning the object to be processed on a rotary stage on which the object to be processed such as a semiconductor wafer is placed, the object to be processed is peripherally placed on the rotary stage. The object to be processed that has been exposed and subjected to the pre-alignment and peripheral exposure is subjected to pattern exposure on an exposure stage.

Further, in the exposure method of the present invention, pre-alignment or peripheral exposure of the object to be processed on the rotary stage and pattern exposure on the exposure stage are simultaneously performed.

Further, the exposure apparatus of the present invention is arranged such that the light source for emitting irradiation light such as ultraviolet rays, the exposure stage for mounting an object to be processed such as a semiconductor wafer, and the photomask on which the wiring pattern is formed are used. A first optical system that performs pattern exposure by irradiating an object to be processed on the exposure stage with irradiation light; a rotary stage on which the object to be processed is placed and prealignment of the object to be processed is performed; A second optical system provided with a spectroscopic unit for spectroscopically dividing the irradiation light and a light control unit for controlling an irradiation position of the irradiation light spectroscopically dispersed by the spectroscopic unit. After alignment, peripheral exposure is performed by the second optical system.

The exposure apparatus of the present invention includes a first light source that emits first irradiation light such as ultraviolet rays, an exposure stage on which an object to be processed such as a semiconductor wafer is mounted, and a photomask on which a wiring pattern is formed. A first optical system that performs pattern exposure by irradiating the object to be processed on the exposure stage with the first irradiation light via a substrate and the pre-alignment of the object to be processed and the object to be processed. And a second optical system including a second light source that emits second irradiation light such as another ultraviolet ray and a light control unit that controls an irradiation position of the second irradiation light. In the above, after pre-alignment of the object to be processed, peripheral exposure is performed by the second optical system.

Furthermore, in the exposure apparatus of the present invention, a light shielding member is provided near the exposure stage and the rotary stage.

[0016]

According to the above-mentioned means, the exposure apparatus is provided with the second optical means having the spectroscopic means for separating the irradiation light emitted from the light source and the light control means for controlling the irradiation portion of the irradiation light dispersed by the above-mentioned spectroscopic means. By including the system, after the pre-alignment of the object to be processed on the rotary stage, the peripheral optical exposure can be performed on the rotary stage by the second optical system, and the pre-alignment and the peripheral exposure can be performed. The object can be pattern-exposed on the exposure stage.

Thus, while the pre-alignment and peripheral exposure of the processed object are pattern-exposed on the exposure stage, other processed objects can be pre-aligned or peripheral-exposed on the rotary stage.

As a result, the pre-alignment or peripheral exposure of the object to be processed and the pattern exposure of another object to be processed can be performed simultaneously on the rotary stage and the exposure stage, so that the throughput in the exposure processing of the object to be processed is improved. Can be planned.

Further, since the peripheral exposure of the object to be processed can be performed on the rotary stage of the exposure apparatus, the exposure processing can be performed without using the peripheral exposure apparatus.

Further, since the light shielding member is provided near the exposure stage and the rotary stage, it is possible to prevent leakage of the irradiation light in each of the peripheral exposure and the pattern exposure.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing an embodiment of the structure of an exposure apparatus according to the present invention, and FIG. 2 is a procedure conceptual diagram showing an embodiment of a work procedure in the exposure method of the present invention.

As an example of the exposure apparatus according to this embodiment, a reduction projection exposure apparatus for reducing the wiring pattern formed on the photomask to ⅕ and exposing it will be described.

First, the structure is such that irradiation light 2 such as ultraviolet rays is used.
Of the irradiation light 2 through a mercury lamp 1 as a light source that emits light, an exposure stage 4 on which a semiconductor wafer 3 that is an object to be processed is placed, and a reticle 5 that is a photomask on which a wiring pattern is formed. A first optical system 6 for performing pattern exposure by irradiating the semiconductor wafer 3 on 4;
A pre-alignment stage 7 that is a rotary stage on which the semiconductor wafer 3 is placed and pre-alignment of the semiconductor wafer 3 is performed, a spectroscopic mirror 8 that is a spectroscopic unit that disperses the irradiation light 2, and irradiation light that is spectrally separated by the spectral mirror 8. Second optical system 10 provided with a light control means 9 for controlling the irradiation position of the second semiconductor wafer 3 onto the semiconductor wafer 3. After the pre-alignment of the semiconductor wafer 3 on the pre-alignment stage 7, the second optical system 10 is placed on the pre-alignment stage 7. 2 The peripheral exposure 15 of the semiconductor wafer 3 is performed by the optical system 10.

Further, in the reduction projection exposure apparatus of this embodiment,
A light blocking plate 11 which is a light blocking member is provided near the space between the exposure stage 4 and the pre-alignment stage 7.

Here, the first optical system 6 includes an illumination system lens 6a for converging the irradiation light 2, a reticle 5 having a wiring pattern formed thereon, and a projection lens 6b for projecting the wiring pattern formed on the reticle 5. It consists of and.

Therefore, the irradiation light 2 such as ultraviolet rays emitted from the mercury lamp 1 is applied to the reticle 5, which is a photomask, via the illumination system lens 6a, and the image of the wiring pattern formed on the reticle 5 is further imaged. , Projection lens 6
It is reduced to 1/5 by b and transferred onto the semiconductor wafer 3.

The second optical system 10 includes a spectroscopic mirror 8 that disperses the irradiation light 2, and a light control unit 9 that controls the irradiation position of the irradiation light 2 that is dispersed by the spectroscopic mirror 8 onto the semiconductor wafer 3. , And an optical fiber 10a connecting the spectral mirror 8 and the light control means 9.

Therefore, the irradiation light 2 such as ultraviolet rays which is split by the spectral mirror 8 passes through the optical fiber 10a,
The edge of the semiconductor wafer 3 is irradiated from the irradiation nozzle 9a.

Here, the light control means 9 controls the operation of the irradiation nozzle 9a for irradiating the irradiation light 2 using a control program.

That is, in the control program, for example, the locus of the edge portion of the semiconductor wafer 3 which rotates by θ on the pre-alignment stage 7 is divided into a circumferential portion and an orientation flat portion, and further, the radius of the semiconductor wafer 3 and the like. Is recognized in advance as a parameter.

Therefore, according to the control program,
The irradiation nozzle 9a can be moved along the trajectory of the edge portion of the semiconductor wafer 3 which rotates by θ on the pre-alignment stage 7 (actually, the irradiation nozzle 9a is moved when the orientation flat portion of the semiconductor wafer 3 is irradiated. And the irradiation of the circumference of the semiconductor wafer 3 is
It is performed only by θ rotation of the pre-alignment stage 7).

Further, in the reduction projection exposure apparatus of this embodiment,
A loader 12 that is a mechanism for loading the semiconductor wafer 3 and an unloader 13 that is a mechanism for unloading the semiconductor wafer 3 after the exposure processing are installed.

Next, the exposure method according to this embodiment will be described.

First, the semiconductor wafer 3 is transferred from the loader 12 and the pre-alignment stage 7 which is a rotary stage.
Place on top.

Here, the alignment by the orientation flat portion of the semiconductor wafer 3 (hereinafter referred to as the orientation flat), that is, the orientation flat alignment (pre-alignment).
Do 14.

Further, the peripheral exposure 15 of the semiconductor wafer 3 is performed on the pre-alignment stage 7 by the second optical system 10.

At this time, the peripheral exposure 15 on the circumferential portion of the semiconductor wafer 3 is performed only by the θ rotation of the pre-alignment stage 7, and the peripheral exposure 15 on the orientation flat portion of the semiconductor wafer 3 causes the irradiation nozzle 9a by the control program. Irradiation light 2 is applied to the orientation flat while controlling the drive.
Irradiate.

As a result, the edge portion of the semiconductor wafer 3 is subjected to peripheral exposure 15.

After that, the semiconductor wafer 3 for which the peripheral exposure 15 has been completed is transferred onto the exposure stage 4, and pattern exposure is performed by the first optical system 6.

Further, after the pattern exposure is completed, the semiconductor wafer 3 is transported and accommodated in the unloader 13.

Since there is a difference in processing time for processing one semiconductor wafer 3 between pattern exposure and pre-alignment (for example, pattern exposure is about 1 minute and pre-alignment is about 10 seconds), 1 By using the time during the pattern exposure of the first semiconductor wafer 3, another semiconductor wafer 3 (here,
The peripheral exposure 15 of the second semiconductor wafer 3) can be performed.

That is, the reduction projection exposure apparatus of this embodiment simultaneously performs pre-alignment or peripheral exposure 15 of the semiconductor wafer 3 on the pre-alignment stage 7 and pattern exposure of another semiconductor wafer 3 on the exposure stage 4. It is something to do.

Here, a method for simultaneously performing pre-alignment or peripheral exposure 15 and pattern exposure will be described in detail with reference to FIGS.

First, the first semiconductor wafer 3 among the semiconductor wafers 3 set in the loader 12 is conveyed to the pre-alignment stage 7 and placed there.

Therefore, the orientation flat alignment 14 (pre-alignment) is performed, and further the pre-alignment stage 7
Above, the peripheral exposure 15 of the first semiconductor wafer 3 is performed by the second optical system 10.

After that, the first semiconductor wafer 3 is conveyed to and placed on the exposure stage 4.

Then, the pattern exposure 16 of the first semiconductor wafer 3, that is, the pattern exposure, is performed by the first optical system 6.

At this time, while the second semiconductor wafer 3 is conveyed onto the pre-alignment stage 7 and the pattern exposure 16 of the first semiconductor wafer 3 is performed, that is, the first semiconductor wafer 3 is exposed. Simultaneously with the pattern exposure 16 of No. 3, the orientation flat alignment 14 and the peripheral exposure 15 of the second semiconductor wafer 3 are performed on the pre-alignment stage 7.

Thereafter, when the pattern exposure 16 of the first semiconductor wafer 3 is completed, the first semiconductor wafer 3 is accommodated in the unloader 13, and the orientation flat alignment 14 and the peripheral exposure 15 are completed. The wafer 3 is transferred to the exposure stage 4.

That is, thereafter, the processing of the third and fourth wafers and the semiconductor wafer 3 can be repeated up to the n-th wafer.

In the exposure method according to this embodiment, the peripheral exposure 15 of the second semiconductor wafer 3 is completed while the pattern exposure 16 of the first semiconductor wafer 3 is being performed. The throughput of the exposure process is only the increase in the time required for the peripheral exposure 15 of the first semiconductor wafer 3.

Next, the function and effect obtained by the exposure method and apparatus of this embodiment will be described.

That is, the exposure device disperses the irradiation light 2 such as ultraviolet rays emitted from the mercury lamp 1 into a spectroscopic mirror 8.
And the second optical system 10 having the light control means 9 for controlling the irradiation position of the irradiation light 2 separated by the spectroscopic mirror 8, so that the pre-alignment stage 7 which is a rotary stage can be used to pre-process the semiconductor wafer 3. After the alignment, the peripheral exposure 15 can be performed by the second optical system 10 on the pre-alignment stage 7, and
The semiconductor wafer 3 which has been subjected to the pre-alignment and the peripheral exposure 15 can be subjected to the pattern exposure 16, that is, the pattern exposure, on the exposure stage 4.

As a result, the semiconductor wafer 3 having undergone the pre-alignment and peripheral exposure 15 is pattern-exposed on the exposure stage 4, while another semiconductor wafer 3 is pre-aligned or peripheral-exposed 15 on the pre-alignment stage 7. You can

As a result, on the pre-alignment stage 7 and the exposure stage 4, the pre-alignment of the semiconductor wafer 3 or the peripheral exposure 15 and the pattern exposure of another semiconductor wafer 3 can be performed at the same time. Throughput can be improved.

In other words, in the entire exposure process, it is possible to obtain the same effect as eliminating the process of the peripheral exposure 15.

Since the peripheral exposure 15 of the semiconductor wafer 3 can also be performed on the pre-alignment stage 7 of the exposure apparatus, the exposure processing can be performed without using the peripheral exposure apparatus, and the number of apparatuses can be reduced. Can be planned.

As a result, it is possible to reduce the cost of the entire apparatus relating to the entire exposure process.

The exposure apparatus of the present embodiment can produce the above effects by modifying the exposure apparatus.
The number of equipment can be reduced.

Further, since the light shielding plate 11 as a light shielding member is provided between the exposure stage 4 and the pre-alignment stage 7, leakage of the irradiation light 2 in each of the peripheral exposure 15 or the pattern exposure is prevented. be able to.

As a result, the peripheral exposure 15 or the pattern exposure can be performed with high accuracy.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, although the exposure apparatus described in the above embodiment is a 1/5 reduction projection exposure apparatus, the exposure apparatus may be a 1/1 aligner (exposure apparatus) or the like.

Further, in the exposure apparatus of the above embodiment, the light source is 1
However, like the exposure apparatus of another embodiment shown in FIG. 3, two light sources, that is, the first light source 17 and the second light source, are used.
The light source 18 may be included.

The structure of the exposure apparatus in this case will be described. The first light source 1 for emitting the first irradiation light 19 such as ultraviolet rays.
7, the exposure stage 4 on which the semiconductor wafer 3 to be processed is mounted, and the first irradiation light 19 through the reticle 5 which is a photomask on which a wiring pattern is formed. The first optical system 6 that performs pattern exposure by irradiating the semiconductor wafer 3, the pre-alignment stage 7 that is a rotary stage on which the semiconductor wafer 3 is placed and the semiconductor wafer 3 is pre-aligned, and other first ultraviolet light The second pre-alignment of the semiconductor wafer 3 on the pre-alignment stage 7 is composed of the second light source 18 that emits the second irradiation light 20 and the second optical system 10 that includes the light control unit 9 that controls the irradiation position of the second irradiation light 20. After that, the second optical system 10 exposes the periphery 15 (see FIG. 2).
Is to do.

Even in the exposure apparatus provided with two light sources, the same effects as those of the exposure apparatus of the above embodiment can be obtained.

Further, although the exposure apparatus of the above-mentioned embodiment performs the peripheral exposure on the pre-alignment stage,
As another method of performing the peripheral exposure, first, as in the exposure apparatus of another embodiment shown in FIG. 4, the concave lens 21 and the chrome disk 22 are inserted between the projection lens 6b of the first optical system 6 and the semiconductor wafer 3. Then, peripheral exposure 15 (see FIG. 2) of the semiconductor wafer 3 is performed on the exposure stage 4, and then the concave lens 2
By removing 1 and the chrome disk 22, pattern exposure of the semiconductor wafer 3 is performed on the exposure stage 4.

Further, as another method for performing the peripheral exposure,
A peripheral exposure mechanism may be provided in the coating machine.

That is, peripheral exposure is performed while rotating the semiconductor wafer on the spinner of the coating machine, not on the pre-alignment stage.

Further, in the exposure apparatus of the above-described embodiment, when the orientation flat portion of the semiconductor wafer is exposed to the periphery, the irradiation nozzle moves along the orientation flat portion of the semiconductor wafer by the drive control of the control program. By installing a detection means such as an optical sensor near the side surface of the alignment stage, it is possible to detect the orientation flat portion of the semiconductor wafer without using the control program. Good.

As a result, it is possible to expose the orientation flat portion of the semiconductor wafer to the periphery.

[0073]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

(1). Pre-alignment and peripheral exposure are performed by having a spectroscopic unit that disperses the irradiation light emitted from the light source and a second optical system that includes a light control unit that controls the irradiation position of the irradiation light that has been dispersed by the spectroscopic unit. It is possible to perform other pre-alignment or peripheral exposure on the rotary stage while pattern-exposing the finished work on the exposure stage.

As a result, the pre-alignment or peripheral exposure of the object to be processed and the pattern exposure of the other object to be processed can be performed simultaneously on the rotary stage and the exposure stage, so that the throughput in the exposure processing of the object to be processed can be improved. Can be planned.

(2). Since the peripheral exposure of the object to be processed can be performed on the rotary stage of the exposure apparatus, the exposure processing can be performed without using the peripheral exposure apparatus, and the number of apparatuses can be reduced.

As a result, it is possible to reduce the cost of the entire apparatus relating to the entire exposure process.

(3). By providing the light shielding member near the exposure stage and the rotation stage, it is possible to prevent leakage of irradiation light in each of the peripheral exposure and the pattern exposure.

As a result, peripheral exposure or pattern exposure can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a structural conceptual view showing an embodiment of the structure of an exposure apparatus according to the present invention.

FIG. 2 is a procedure conceptual diagram showing an example of a work procedure in the exposure method of the present invention.

FIG. 3 is a structural conceptual diagram showing an example of the structure of an exposure apparatus that is another embodiment of the present invention.

FIG. 4 is a structural conceptual diagram showing an example of the structure of an exposure apparatus that is another embodiment of the present invention.

[Explanation of symbols]

 1 Mercury Lamp (Light Source) 2 Irradiation Light 3 Semiconductor Wafer (Processing Object) 4 Exposure Stage 5 Reticle (Photomask) 6 First Optical System 6a Illumination System Lens 6b Projection Lens 7 Pre-Alignment Stage (Rotation Stage) 8 Spectral Mirror (Spectroscopic means) 9 Light control means 9a Irradiation nozzle 10 Second optical system 10a Optical fiber 11 Light shielding plate (light shielding member) 12 Loader 13 Unloader 14 Orientation flat alignment 15 Peripheral exposure 16 Pattern exposure 17 First light source 18 Second light source 19 1st Irradiation light 20 Second irradiation light 21 Concave lens 22 Chrome disk

Claims (7)

[Claims] 1. An exposure method for performing pattern exposure and peripheral exposure on an object to be processed such as a semiconductor wafer after pre-aligning the object to be processed on a rotary stage on which the object to be processed is mounted. An exposure method, which comprises subjecting the object to be processed to peripheral exposure on the rotary stage, and subjecting the object to be subjected to the pre-alignment and peripheral exposure to pattern exposure on an exposure stage. 2. The exposure method according to claim 1, wherein pre-alignment or peripheral exposure of the object to be processed on the rotary stage and pattern exposure on the exposure stage are performed simultaneously. Exposure method. 3. An exposure apparatus for performing pattern exposure and peripheral exposure on an object to be processed such as a semiconductor wafer, wherein the light source emits irradiation light such as ultraviolet rays, and an exposure stage on which the object to be processed is placed. A first optical system for performing pattern exposure by irradiating the object to be processed on the exposure stage with the irradiation light through a photomask on which a wiring pattern is formed; A rotary stage for pre-aligning the object to be processed; and a second optical system including a spectroscopic unit for spectroscopically displacing the irradiation light and a light control unit for controlling an irradiation position of the irradiation light dispersed by the spectroscopic unit. Then, after the pre-alignment of the object to be processed on the rotary stage, peripheral exposure is performed by the second optical system. 4. The exposure apparatus according to claim 3, wherein the spectroscopic unit is a spectroscopic mirror that disperses the irradiation light. 5. An exposure apparatus for performing pattern exposure and peripheral exposure on an object to be processed such as a semiconductor wafer, the first light source emitting a first irradiation light such as ultraviolet light, and an exposure for placing the object to be processed. Optical system for performing pattern exposure by irradiating the object to be processed on the exposure stage with the first irradiation light through a photomask having a wiring pattern formed thereon, and the object to be processed. A rotary stage that is mounted and that pre-aligns the object to be processed, a second light source that emits second irradiation light such as another ultraviolet ray, and a light control unit that controls an irradiation position of the second irradiation light are provided. And a second optical system, and the peripheral exposure is performed by the second optical system after pre-alignment of the object to be processed on the rotary stage. 6. The exposure apparatus according to claim 3, 4 or 5, wherein a light shielding member is provided near the exposure stage and the rotary stage. 7. The exposure apparatus according to claim 3, 4, 5 or 6, wherein a mercury lamp is installed as the light source, the first light source or the second light source.