JPS6358930A - Exposing apparatus - Google Patents

Abstract

PURPOSE:To largely reduce the number of steps during the production of an original plate by selecting a necessary pattern for an exposure from original plate patterns, and irradiating only selected pattern with an optical beam by scanning means to form a circuit pattern on a photosensitive material. CONSTITUTION:An opening controller 12 receives a control signal corresponding to the size and shape of a pattern selected from a central processing unit 11 to drive a variable opening mechanism 2 and controls the opening, i.e., the size and shape of an optical beam to be adapted for the selected pattern. A scan controller 13 receives a control signal responsive to the position of the selected pattern from the unit 11, controls to drive a scanning mechanism 5, and irradiates the selected pattern with the beam to project only the pattern on a wafer 9. Thus, a plurality of original plate patterns having high universality are formed on an original plate 7, necessary pattern is selected from the original plate patterns to form a circuit pattern on a photosensitive material 9. Accordingly, the number of steps can be largely reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an exposure apparatus used for manufacturing semiconductors such as custom ICs.

[Conventional technology]

Conventionally, in the manufacturing process of custom ICs such as gate arrays, each I
Common circuits in C were created using a common original plate, and only the circuit pattern portions that differed from IC to IC were created using an overlapping exposure method.

One is a method using a light exposure device, in which the number of original plates corresponding to the different circuit patterns for each type of IC is prepared, and the wafer exposed with the common original plate is overlaid and exposed. It was compatible.

The other is a method using an electron beam exposure device, in which the direction of the electron beam is controlled according to the circuit pattern that differs from IC to IC, and the circuit is created with a surface structure.

[Problem that the invention seeks to solve]

The first technique has the problem that since there are many types of originals, it takes a lot of money and time to create them, and the manufacturing cost per IC increases.

The second technique has problems in that the manufacturing equipment is expensive and the throughput is low.

The purpose of the present invention was made in view of these conventional problems, and is to provide an exposure apparatus that uses light exposure, minimizes the number of times an original is created, reduces manufacturing costs, and improves throughput. There is a particular thing.

[Means for solving problems]

In order to achieve this object, the exposure apparatus of the present invention has the following components (i) to (iv).

(i) An original plate on which a plurality of original patterns are formed (ii) A scanning means capable of sequentially irradiating each original pattern with a light beam (
5) <1ii) Select one from each original pattern,
control means (11, 1) for controlling the scanning means (5) to sequentially irradiate the selected original pattern with the light beam;
3) (iv) Projection means (8) for projecting the original pattern illuminated by the Is light beam onto the photosensitive material (9) [Operation] The exposure apparatus of the present invention projects a highly versatile original pattern on the original (7). A plurality of patterns are formed, and from among these original patterns, the one required for exposure is selected as τt,ll? 11 means (11,
13), and the scanning means (5) irradiates a light beam only onto the selected pattern, thereby exposing the photosensitive material (9).
A circuit pattern is formed on top.

Therefore, one original plate can be used for exposing many types of ICs, and the number of man-hours involved in preparing the original plate can be significantly reduced.

〔Example〕

FIG. 1 is a schematic diagram showing an embodiment of an exposure apparatus of the present invention.

In the figure, a light beam emitted from a light source 1 such as a laser passes through a variable aperture mechanism 2, passes through a lens 3, a reflection mirror 4, and enters a light beam scanning mechanism 5. The light beam scanning mechanism 5 includes deflection means for deflecting the incident light beam. Examples of this deflection means include a galvanometer mirror, a polygon mirror, an acousto-optic deflector, and the like.

The light beam deflected by this scanning mechanism 5 is reflected by a reflecting mirror 6.
It is reflected by the beam and enters the original plate 7.

This original plate 7 consists of a portion through which incident light passes and a portion through which it does not pass, and the light-transmitting portions form a plurality of original patterns for forming circuit patterns, which will be described later.

The variable aperture 2 and this original 7 have a conjugate relationship with respect to the lens 3, and by changing the size and shape of the aperture of the variable aperture 2, the light beam can be made to enter only one pattern on the original 7. can do. Further, the scanning mechanism 5 can irradiate any pattern on the original 7 with the light beam by two-dimensionally biasing the light beam on the original 7.

The light that has passed through the pattern on the original plate 7 passes through a reduction projection lens 8 and then forms an image on a wafer 9 coated with photoresist as a photosensitive material. The wafer 9 is placed on a three-dimensionally movable stage 10.

The central processing unit 11 centrally controls the operation of the exposure apparatus via the aperture control device 12, the scanning control π device 13, the original control bag W14, and the stage control device 15.

The aperture control device 12 drives the variable aperture mechanism 2 in response to a control signal corresponding to the size and shape of the pattern selected from the central processing unit 11, and adjusts the aperture, that is, the size of the light beam, to adapt to the selected pattern. control the shape.

The scanning control device 13 receives a control signal corresponding to the position of the selected pattern from the central processing unit 11 and controls the scanning mechanism 5.
is driven and controlled to irradiate the selected pattern with a light beam so that only this pattern is projected onto the wafer 9.

The original control device 14 receives a command from the central processing unit 11 and displaces the original 7 two-dimensionally.

The stage control device 15 receives a command from the central processing unit 11, drives the stage 10, and displaces the wafer 9 two-dimensionally.

Next, the operation of this embodiment will be explained.

FIG. 2(a) is a diagram showing an exposed field 91 (a region of the wafer 9 where the entire Ir4 region of the original 7 is projected) which is a part of the surface of the wafer 8, and shows the exposure field 91 of the wafer 8. This shows the state before processing. The entire exposed area of the wafer 9 is made up of a plurality of exposed fields 91. In the exposed region 91, there are 12 contact holes 91a to 9 indicated by hatching downward to the right.
11 is formed in advance. In reality, far more contact holes are formed, but for the sake of convenience, 12 will be described.

The figure (b) shows the original plate 7 corresponding to the exposed field S1.
In this effective area 71, there are six circuit patterns 71 that transmit the incident light beam.
3 to 71f are formed. This original pattern is highly versatile and can be used as circuit patterns for various ICs.

FIG. 4C shows a state after exposure processing is performed on the exposed field S1 using the effective area 71 of the original 7. FIG.

This exposure processing operation will be explained in detail below.

First, the central processing unit 11 sends a control signal to the original control device 14 and the stage control device 15, and sends a control signal to the original 7 and the wafer 9.
This embodiment is a reduction projection optical device, and a plurality of patterns of moving areas 71 of the original 7 are repeatedly formed on the wafer 9 by a so-called step-and-repeat operation. At the same time, an exposed field 91 of the wafer 9 to be exposed first is opposed to the original plate 7. Regarding this positioning technology,
It is publicly known from JP 0-130742 and the like.

When this positioning is completed, the central processing unit 11 controls the variable aperture 2 via the aperture control device 12 and the scanning control device 13 based on the data previously stored in the built-in storage device.
, drives the scanning mechanism 5 to control the size, shape, and irradiation position of the light beam. After completing this control, the central processing unit 11
Light transmission by light rA1 is started. Thereby, the light beam is irradiated so as to cover only one of the original patterns, for example, pattern 71a, in the effective area 71 shown in FIG. 2(b). In FIG. 2B, the irradiation area 1a formed by this light beam is indicated by hatching upward to the right. In this way, the irradiation area formed on the original plate 7 by the light beam is determined by the need to transmit the central part of the irradiation area with a flat cross-sectional intensity distribution from the pattern on the original plate 7, and the need to allow for beam positioning errors. , is set considerably larger than the size of the pattern.

As shown in FIG. 2C, the original pattern 71a irradiated with the light beam is projected by the projection lens 8 as an image 91m spanning contact holes 91a and 91d.

After processing such as development, the latent image 91m is formed in both contact holes 9.
1a and 91d are brought into conduction.

When the projection exposure of the pattern 71b is completed, the central processing unit 11 stops the light transmission of the light source 1 using a light shielding device (not shown). After that, the scanning mechanism 5 is driven again by the scanning control Il device 13 to change the irradiation position of the light beam,
Light transmission of light B1 is restarted. As a result, the light beam forms an irradiation area 1b on the area 71 that includes only the original pattern 71C shown in FIG. 2(b). pattern 7ic
Since the size and shape of the variable aperture 2 are the same as the pattern 7ia to which the light beam was irradiated last time, there is no need to change the size and shape of the variable aperture 2 by the aperture control T1 device 12.

When the projection exposure of this pattern 71C is completed, the central processing unit 11 stops the light transmission of the light source 1, and the scanning control device 1
3, the scanning mechanism 5 is driven again to change the irradiation position of the light beam, and the light source 1 resumes light transmission. This causes the light beam to move to the 2nd U! An irradiation area 1C is formed that includes only the original pattern 71e in the effective area 71 shown in J(b).

Since the size and shape of the pattern 71e are also the same as the pattern 71C that was irradiated with the light beam last time, the size and shape of the variable aperture 2 are not changed by the aperture control device 12.

As a result of the projection exposure of the original patterns 71c and 71e, after processing such as development, the contact holes 91C and 91f in the exposed area 91 are projected by the projection 1191n of the pattern 71C, and the contact holes 91h and 91 are projected as a projected image 910 of the pattern 71e. , respectively, to conduction.

When all of the selected original patterns on the effective area 71 are transferred onto the wafer 9 in the above manner, the central processing unit 11 drives the stage 10 via the stage control device 15 to The exposed field to be exposed to light is made to face the effective area 71 of the original plate 7. Then, the above-described operation is repeated to expose the entire surface of the wafer 9.

As in this example of exposure processing, when the pattern to be projected is the same and there is no need to change the size and shape of the variable aperture 2, a fixed aperture can be used instead of the variable aperture 2.

FIGS. 3A, 3B, and 3C are diagrams used to explain another exposure process. This exposure process is performed by dividing the exposure of the same field of the wafer 9 into multiple times and by relatively displacing the original 7 and the wafer 9 between the exposures. This allows the pattern spacing to be made smaller.

In FIG. 3(a), four original patterns 722 to 72d are formed in the effective area 72 of the original 7. As shown in FIG. By scanning in the same manner as in the previous example, the light beam illuminates the original plate 7 with irradiation areas 1d to 1g having a size and shape that include these four patterns.
Form on top one after another.

As a result, latent images 922-32d of circuit patterns corresponding to the respective patterns 72a-72d are formed in the exposed field 92 of the wafer S, as shown in FIG. 3(b).

This is performed over the entire exposed field 92 of the wafer 9 to complete the first exposure process.

Next, the central processing unit 11 sends a control signal to at least one of the original control device 13 and the stage control device 15, and changes the relative position between the original 7 and the wafer 9 as shown in FIG. 3(C).
As shown in FIG. 2, the position at the time of the first exposure process is displaced by a small amount ld in one direction.

By scanning the light beam on the original 7 that is displaced relative to the wafer 9, four original patterns 72a to 72 are created.
The irradiation areas 1h to 1k are sequentially formed for the area d, and the exposed field 92 is exposed.

This is carried out over the entire exposed field 92 of the wafer 9 to complete the second exposure process.

As a result, as shown in FIG. 3(d), a latent image 92e of a circuit pattern corresponding to each of the original patterns 723 to 72d displaced by a distance d appears on the exposed field 92 of the wafer 8.
~92h is formed. A latent image 92e is formed between latent images 92a and 92b formed by the first exposure,
The latent image 92f is on the right side of the latent image 92b, and the latent image 92g is on the right side of the latent image 92b.
2c and 92d, a latent image 92h is formed on the right side of the latent image 92d. That is, the second exposure is performed within the same field as the first exposure field.

Since the size of the light beam irradiation area on the original plate 7 is defined by the above-mentioned reason, the interval between the original patterns on the original plate 7 is restricted to not be smaller than the size of the irradiation area.

However, by using the above exposure processing method, the interval between the latent image patterns on the wafer 9 can be reduced without being subject to this restriction.

FIGS. 4(a) to 4(d) are explanatory diagrams for yet another exposure process. In this exposure process, the same field of the wafer 9 is exposed using a plurality of types of original patterns.

The original plate 7 used in this embodiment includes three effective areas, and three types of original plate patterns having different shapes and sizes are formed in each effective area.

FIG. 4(a) shows the first effective area 73 where the first type original patterns 733 to 73h are formed, and FIG. 4(b) shows the second effective area 73 where the second type original patterns 743 to 74h are formed. 74, and the figure (c) shows the third type of original pattern 7Sa~7.
The third effective area 75 in which 5C is formed is shown. FIG. 4D shows the exposed field 93 of the wafer 9 corresponding to the effective areas of the original plate 7. FIG.

First, the first position of original plate 7 is
The effective area 73 and the exposed field area 93 of the wafer 9 are made to face each other, and the variable aperture 2 is adjusted to match the first original patterns 73b, 73d, 73e, and 73g. Then, by the same scanning as in the previous example, the light beam is applied to the first original patterns 73b and 73d on the first effective area 73.
, 73e, and 73g are sequentially irradiated.

When the transfer of the first original pattern is completed over the entire exposed field 93 of the wafer S, the alignment operation is performed again to make the second effective area 74 and the exposed field 93 face each other, and the variable aperture 2 is moved to the second The images are adjusted according to the original patterns 74b, 74d, 74e, and 74g. By scanning the light beam, the light beam is directed to the second effective area 7.
Second original pattern 74b, 74d, 74e, 7 on 4
4g is sequentially irradiated.

When the transfer of the second master pattern is completed over the entire exposed field 93 of the wafer 9, the positioning operation is performed again to make the third effective area 75 and the exposed field 93 face each other, and at the same time, the variable aperture 2 is moved to the third The third patterns 75a and 75C on the third effective area 75 are sequentially irradiated with the light beam by scanning the zero-order light beam adjusted according to the original patterns 75a and 75C. Exposure of this original pattern is also performed over the entire exposed field 93 of the wafer 9.

As a result of the above exposure process, as shown in FIG. 4(d), each pattern 73b, 73
d, 73e, 73g, 74b, 74d, 74e, 74g
, 7Sa, and 7sc, latent images 932 to 93j of circuit patterns are formed, respectively.

In this way, by selectively using a plurality of types of original patterns formed on one original plate 7, a wide variety of wiring patterns can be formed.

Various original plate patterns can be formed not only on one original plate 7 but also on a plurality of original plates. In this case, each original plate may be replaced every time the exposure process is completed.

This exchange can be automated by employing the technique disclosed in Japanese Patent Application Laid-Open No. 57-64928.

FIG. 5 shows another embodiment of the invention.

In this embodiment, an exposure light source 16 is used to simultaneously expose the entire pattern in the effective area of the master 7 to the entire exposed field of the wafer 9, and an optical integrator 17 is used to uniformize the light tA17 generated. , original plate exchange device 1
9 is added to the configuration of the embodiment of FIG. 1, and the reflecting mirror 6 of the embodiment of FIG. 1 is replaced with a half mirror 18.

In this example, one exposure device can perform the batch exposure of the original,
The above-described scanning exposure performed by scanning the light beam from the light source 1 can be performed one after the other.

FIG. 6 shows the original plate 7 used in the batch exposure process according to this embodiment.
7 is a diagram showing an effective area 76 of FIG. In this region 76, contact holes 91a to 912 shown in FIG. 2(a) are formed.
Original pattern 763-76 for forming! is formed.

An example of the operation of this embodiment will be described below.

The central processing unit 11 first operates the master changing device 19 to insert the batch exposure master 7 having the effective area 76 between the half mirror 18 and the projection lens 8, and then operates the master control device 14 and the stage control device. 15 through this original version 7
and the wafer 9 are aligned.

In addition, as the original plate exchange device 19, for example, Japanese Patent Application Laid-Open No. 57-6
The device disclosed in No. 4928 is mentioned.

Subsequently, the central processing unit 11 causes the batch exposure original 7 to be irradiated with light from the batch exposure light 'fL16 via the integrator 17 and the half mirror 18. As shown by the downward-sloping hatching in FIG.
6 is irradiated with uniform intensity. As a result of this blanket exposure, latent images of contact holes 913 to 91' similar to the exposed field 91 shown in FIG. 2(a) are formed in the exposed field of the wafer 9. The above batch exposure is repeated by a step-and-repeat operation to expose the entire exposed field of the wafer 9.

- When the entire wafer 9 has been exposed by the blanket exposure, the central processing unit 11 operates the master changing device 19 to
The batch exposure original 7 having a
) is inserted between the half mirror 18 and the projection lens 8, and the scanning exposure original 7 and the wafer 9 are aligned.

Next, the central processing unit 11 adjusts the size and shape of the light beam through the aperture control device 12 to match each of the original patterns 713 to 71f in FIG. By alternately repeating the adjustment of the irradiation position of each light beam and the transmission of light by the light source 1, latent images of the selected original patterns 71a, 7ic, and 71e are formed on the exposed field of the wafer 9. Perform this on the entire exposed field.

The above exposure processing results are similar to those shown in FIG. 2(c).

In this embodiment, the scanning exposure light source 1 and the batch exposure light source 1B have the same or similar wavelengths to obtain an image with little aberration.

In the scanning exposure processing of each of the above embodiments, it is effective to increase the exposure power density per unit area and shorten the exposure time in order to increase the throughput. For this purpose, it is better to reduce the opening area of the original pattern through which the light from the light l1111 passes. To this end, it is sufficient to select a photoresist that requires only a small area of exposure.

For example, if the area where the resist is to be left is small, prepare an original pattern for exposing that area.
You can transfer this pattern to a negative resist, or if the area from which the resist is to be removed is small, you can prepare an original pattern for exposing that area and transfer this pattern to a positive resist. .

In each of the above embodiments, the original plate 7 is of a transmissive type that allows light to pass through only the part of the original pattern.
The present invention is not limited to this, and a reflective type in which only the original pattern portion reflects light may be adopted.

〔Effect of the invention〕

As described above, according to the exposure apparatus of the present invention, the original plate (7)
A plurality of highly versatile original patterns are formed on the original plate, and the control means (
11, 13), and the scanning means (5) irradiates a light beam only on the selected pattern to form a circuit pattern on the photosensitive material (9). The master plate can be used to manufacture many types of semiconductors, and the number of man-hours involved in creating the master plate can be significantly reduced.

In addition, since exposure is performed through the original plate (7), the photosensitive material (9
) The positional accuracy of the pattern exposed on the original pattern is determined by the positional accuracy of the original pattern and does not depend on the positioning accuracy of the scanning means (5). Therefore, the positioning accuracy of the scanning means (5) can be reduced, the scanning speed can be increased accordingly, and pattern formation with high throughput can be realized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of an exposure apparatus of the present invention;
2(a) to 2(e) are diagrams for explaining the steps of exposure processing according to the same embodiment, FIG. 3 is a diagram for explaining the steps of another exposure processing according to the same embodiment, and FIG. is a diagram for explaining still another exposure process according to the same embodiment, FIG. 5 is a schematic configuration diagram showing another embodiment of the present invention, and FIG. 6 is a diagram for explaining an exposure process according to the same embodiment. This is a diagram. [Explanation of symbols of main parts] 7・・・・・・・・・Original version

Claims (1)

[Claims] (1) An original plate on which a plurality of circuit patterns are formed, a scanning means capable of sequentially irradiating each of the circuit patterns with a light beam, and selecting some of the circuit patterns and applying the light beam to the selected circuit patterns. A scanning exposure apparatus comprising: a control means for controlling the scanning means to sequentially irradiate the light beam; and a projection means for projecting a circuit pattern illuminated by the light beam onto a photosensitive material.