JPH10312946A - Device and method for exposure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposing device which can correct proximity effects, can suppress dispersion among and in wavers, can prevent the deterioration of contrasts, and can improve the throughput and a method for using the device. SOLUTION: A prescribed patter is formed by converging and deflecting an electron beam 90 emitted from an electron gun 200 by means of an electro- optical system 60 and a deflecting system 70 and irradiating the pattern forming area 20a of a resist film 12 on the surface of a wafer 10 with the converged and deflected electron beam. A ray of light emitted from a light source 100 is selected through a light-transmitting window 42 formed in a mask 40, and the transmitted light is converged by an optical lens 50 and projected upon a pattern-forming area 20a for exposure. Since the control of the deflection of the deflecting system 70 and the formation of the window 42 are performed based on the CAD design data of the mask 40, the deterioration of contrasts can be prevented, and the throughput of an exposing device can be improved while a precise pattern is formed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, for example, an exposure apparatus for providing a light-shielding mask and selectively irradiating a pattern region formed by electron beam lithography with light to perform exposure, thereby improving contrast. And an exposure method therefor.

[0002]

2. Description of the Related Art In pattern exposure using an electron beam,
Due to forward scattering of the irradiated electrons in the resist and back scattering from the resist base, a slight exposure reaction occurs in the resist around the exposed portion. This causes a reduction in pattern dimensional accuracy in a portion where the pattern is close, that is, a so-called proximity effect. For this reason, in pattern exposure using an electron beam, it is necessary to correct the proximity effect by a pattern dimension correction method, a pattern dose correction method, a representative figure method, a bit map method, a ghost exposure method, a fog exposure method, or the like. .

In the exposure method including the above-described correction operation, particularly, the fogging exposure method, a pattern exposure is performed using an electron beam, and then the entire resist film is exposed using an electron beam again. This is a method to make the amount of scattered electrons generated over the entire surface more uniform,
In addition, variations in pattern dimensional accuracy due to the proximity effect can be suppressed without requiring complicated correction calculations.

However, in the above fogging exposure method, complicated correction calculation is not required prior to exposure, but the same substrate needs to be exposed twice with an electron beam. It becomes longer and high throughput cannot be obtained. In addition, the proximity effect itself cannot be suppressed without reducing the amount of scattered electrons generated by the irradiation of the electron beam inside the resist film.

As a method for solving this problem, a step of exposing a pattern obtained by irradiating the resist film with an electron beam using a resist film which reacts to both light and an electron beam, and forming a pattern forming region in the resist film. An exposure method has been proposed in which a step of exposing the entire surface to light is performed before and after. By this exposure method, the sensitivity of the resist film to the electron beam is improved, and the resist film can be subjected to pattern exposure with a smaller electron beam exposure energy, so that the amount of scattered electrons generated in the resist film by the irradiation of the electron beam is increased. Can be suppressed.

[0006]

However, in the above-described exposure method, a portion of the resist film which should not be exposed to the electron beam is exposed at an exposure intensity of 30 to 50% of a portion to be exposed. In addition, there is a disadvantage that the contrast of the amount of stored energy between the exposed portion and the non-exposed portion is reduced, the cross-sectional shape of the resist pattern is deteriorated, and the process margin (process margin) may be reduced. Further, a writing time of an electron beam for exposing the inverted pattern is required, which causes a problem of reduction in throughput.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exposure apparatus and an exposure apparatus capable of correcting a proximity effect, suppressing variations between wafers and within a wafer, and realizing an improvement in throughput. It is to provide a method.

[0008]

To achieve the above object, an exposure apparatus according to the present invention is an exposure apparatus for forming a predetermined pattern on an exposure resist film responsive to light and an electron beam. Irradiating the resist film, an electron beam writing apparatus for writing a predetermined pattern,
A light-shielding mask having a light-transmitting window provided in accordance with the pattern formed by drawing the electron beam, and a light-shielding mask disposed on an incident optical path of light to the resist film; A light irradiation device for irradiating a predetermined region of the resist film with light.

In the present invention, the light transmission window is preferably made of a material transparent to the wavelength of the exposure light, for example, quartz. Alternatively, it is constituted by an electronic shutter for electrically controlling the transmittance of light from the light irradiation device.

In the present invention, the pattern writing by the electron beam and the light irradiation using the light-shielding mask are performed based on the design data of the light-shielding mask.

Further, the exposure method of the present invention is an exposure method for forming a predetermined pattern on an exposure resist film which reacts with light and an electron beam, wherein the predetermined pattern is formed by irradiating the resist film with an electron beam. An electron beam drawing step of drawing, and a light irradiation step of irradiating the resist film with light and exposing the resist film using a light transmission window provided in accordance with the pattern formed in the electron beam drawing step as a mask.

According to the present invention, a predetermined pattern is formed on a resist film made of a material which reacts with light and an electron beam by using an electron beam. A light-transmitting window is provided in the light-shielding mask in accordance with the area where the pattern is formed (hereinafter, referred to as a pattern-forming area), and the light-shielding mask is installed in an incident light path of light of the light irradiation device, and light is selected. Exposure is performed on the resist film by the selective transmission. Therefore, the contrast of the entire resist film and the throughput can be improved, and the proximity effect in electron beam writing can be suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a conceptual view showing a first embodiment of an exposure apparatus and an exposure method according to the present invention. In FIG. 1, an electron beam drawing apparatus and a light irradiation apparatus for forming a pattern on a resist film by an electron beam are omitted, and only a light-shielding mask and a light-transmitting window and a wafer formed on the light-shielding mask are shown. ing. In FIG. 1, 10
Is a wafer, 12 is a resist film on the wafer surface, 20 and 30 are pattern forming regions on which a pattern is formed on the resist film, 40 is a light-shielding mask (hereinafter simply referred to as a mask), and 41 to 49 are light on the mask. Each shows a transmission window. Note that the resist film 12 of the present embodiment is applied on the wafer surface prior to the exposure operation. The resist film 12 reacts to both light and an electron beam. For example, a novolak-type chemically amplified resist is used. The light transmission windows 41 to 49 are formed of a material transparent to the wavelength of the exposure light, for example, quartz. Here, the light used for the exposure is, for example, a wavelength of 193.
248 nm excimer laser beam.

Hereinafter, an exposure method in the exposure apparatus of the present embodiment will be described with reference to FIG. Prior to the exposure processing, a resist film 12 that reacts with an electron beam and light is applied to the surface of the wafer 10 as described above. In the exposure process, first, as shown in the figure, the pattern formation region 2
By irradiating 0 and 30 with an electron beam, a fine pattern is formed. Then, in the mask 40, light transmission windows 41, 42,... Are formed in accordance with the pattern formation regions 20 and 30.

Next, an exposure process using light is performed using the mask 40 on which the light transmission windows 41, 42,... Are formed.
The light exposure process is performed by a light transmitting window 41 in the mask 40,
Only the light that has passed through... Is irradiated on the resist film on the surface of the wafer 10, that is, only the region where the pattern is formed by the electron beam is exposed to light, and the light is exposed by the mask 40 to the other regions. Since the light is blocked, the exposure processing on the resist film is limited to the pattern formation region.

As described above, according to the exposure apparatus and the exposure method of the present embodiment, a reduction in the contrast of the exposure processing can be avoided while a highly accurate drawing of a fine pattern by an electron beam is realized. Further, since the entire surface of the pattern formation region is exposed to light, the throughput can be improved.

The above-described drawing of the pattern by the electron beam and the exposure of the pattern forming region by the light need not be performed in the above-described order, and any operation may be performed first.

Second Embodiment FIG. 2 is a conceptual view showing a second embodiment of the exposure apparatus and the exposure method according to the present invention. In FIG. 2, 10 is a wafer, 12 is a resist film, 20a is a pattern region formed on the resist film, 40 is a mask, 42 is a light transmitting window,
50 is an optical lens, 60 is an electron optical system, 70 is an electron beam deflection system, 80 is a light beam, 90 is an electron beam, 100 is a light source that generates light, 200 is an electron gun that generates an electron beam, and 300 is, for example, , CAD design data used for CAD and the like.

As shown, the exposure apparatus of the present embodiment
Both a light irradiation device and an electron beam writing device are provided. The light irradiation device includes a light source 100 and an optical lens 50.
It consists of. The electron beam writing apparatus includes an electron gun 200, an electron optical system 60, and an electron beam deflection system 70. Further, the resist film 1 of the present embodiment
2 is formed of a material that reacts to both light and an electron beam, for example, a novolak-type chemically amplified resist, as in the first embodiment. Further, the energy of the irradiation light in the exposure processing is set according to the photosensitive characteristics of the resist film 12 and the like. For example, resist film 1
In the case where 2 is a negative type, the energy is set in a range where the resist film irradiated only with light is removed by the development processing after exposure. On the other hand, when the resist film 12 is of a positive type, the energy of the resist film irradiated only with light is set in a range that remains after the development processing after exposure.

The operation of the exposure apparatus according to the present embodiment will be described below with reference to FIG. Prior to the exposure operation, a photosensitive material is applied to the surface of the wafer 10 to form a resist film 12, as shown in FIG. First, the operation of the electron beam writing apparatus will be described. In the electron beam drawing apparatus, an electron beam 90 generated by an electron gun 200 is converged by an electron optical system 60 and is deflected in a predetermined direction by a deflection system 70 to draw a predetermined pattern on the resist film 12. You. Then, as shown in FIG. 2, a region where a pattern is drawn by an electron beam on the resist film is a so-called pattern forming region 20.
a is formed. As shown, the deflection operation of the deflection system 70 is performed based on the mask CAD design data 300.

Next, the operation of the light irradiation device will be described. In the light irradiation device, for example,
An excimer laser beam 80 having a wavelength of 193 to 248 nm is generated. The light beam 80 generated by the light source 100 enters the optical lens via the mask 40. Note that, of the light rays generated by the light source 100, only the light rays transmitted through the light transmission window of the mask 40 can reach the optical lens, and the other parts are blocked by the mask 40. Here, the light transmission window 42 formed in the mask 40 is, as shown in FIG.
Pattern forming area 2 formed based on mask CAD design data 300 and having a pattern drawn by an electron beam
0a.

The light beam transmitted through the light transmission window 42 is converged by the optical lens 50 and, after its direction is adjusted, is irradiated on the resist film 12. Here, the light transmitting window 42 formed in the mask 40 is formed by the resist film 1 by the electron beam.
Since the pattern is formed in accordance with the pattern forming region in which the pattern is formed in 2, the light exposure process is performed only on the pattern forming region with light. Due to the light blocking effect of the mask 40, light irradiation is not performed on portions of the resist film 12 other than the pattern formation region 20a. As a result, a decrease in the contrast of the exposure processing on the resist film 12 is prevented.

As described above, according to the present embodiment, the electron beam 90 generated by the electron gun 200 is converged and deflected by the electron optical system 60 and the deflecting system 70, and the resist film 12 on the surface of the wafer 10 is deflected. Pattern formation area 2
Irradiate 0a to form a predetermined pattern. Light source 100
Is selected by the light transmitting window 42 formed on the mask 40, the transmitted light is converged by the optical lens 50, and is irradiated to the pattern forming region 20a.
Light exposure is performed. Since the deflection control of the deflection system 70 and the formation of the light transmission window 42 of the mask 40 are performed based on the mask CAD design data, it is possible to prevent a decrease in contrast in the exposure processing, and to improve the throughput while forming a fine pattern with high precision. Improvement can be realized.

In the above description, the formation of the pattern by the electron beam is performed before the exposure process by the light. However, the present invention is not limited to the order of the exposure operation, and the pattern formation by the electron beam and Any of the light exposure processes may be performed first. Also, these operations can be performed simultaneously. In such simultaneous processing, while controlling the deflection of the electron beam 90 by the deflection system 70 based on the mask CAD design data, the light transmission window 42 of the mask 40 is further formed using, for example, an electronic shutter or the like. The light transmittance of the shutter is controlled by a control signal corresponding to the mask CAD design data. Thereby, it is possible to simultaneously perform the pattern drawing by the electron beam and the exposure by the light in real time, thereby realizing higher throughput.

[0025]

As described above, according to the exposure apparatus and the exposure method of the present invention, the proximity effect in electron beam writing can be corrected, a fine pattern can be formed with high accuracy, and the contrast in exposure processing can be reduced. Can be suppressed,
There is an advantage that the throughput can be improved.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a first embodiment of an exposure apparatus and an exposure method according to the present invention.

FIG. 2 is a conceptual diagram showing a second embodiment of the exposure apparatus and the exposure method according to the present invention.

[Explanation of symbols]

Reference numeral 10: wafer, 12: resist film, 20, 20a, 3
0: pattern formation area, 40: mask, 41, 42,
..., 49 ... light transmission window, 50 ... optical lens, 60 ... electron optical system, 70 ... electron beam deflection system, 80 ... light beam, 90 ... electron beam, 100 ... light source, 200 ... electron gun, 300 ... mask CAD design data .

Claims (8)

[Claims] 1. An exposure apparatus for forming a predetermined pattern on a resist film for exposure which reacts to light and an electron beam, said apparatus irradiating said resist film with said electron beam to draw a predetermined pattern. And a light-shielding mask having a light-transmitting window provided in accordance with a pattern formed by drawing the electron beam, and a light-shielding mask disposed in an optical path of light incident on the resist film; An exposure apparatus for irradiating a predetermined region of the resist film with light to perform exposure. 2. The exposure apparatus according to claim 1, wherein the light transmission window of the light shielding mask is formed of quartz. 3. The exposure apparatus according to claim 1, wherein the light transmission window of the light shielding mask is constituted by an electronic shutter for electrically controlling the transmittance of light from the light irradiation device. 4. The pattern writing by the electron beam is performed as follows:
2. The exposure apparatus according to claim 1, wherein the exposure is performed based on design data of the light shielding mask. 5. The light irradiation using the light-shielding mask is performed based on design data of the light-shielding mask.
Exposure apparatus according to the above. 6. An exposure method for forming a predetermined pattern on a resist film for exposure responsive to light and an electron beam, comprising: an electron beam drawing step of drawing a predetermined pattern by irradiating the resist film with an electron beam. A light irradiating step of irradiating the resist film with light using a light transmitting window provided in accordance with the pattern formed in the electron beam drawing step as a mask, and exposing the resist film to light. 7. The exposure method according to claim 6, wherein the step of drawing a pattern by the electron beam is performed based on design data of the light shielding mask. 8. A light irradiation step using the light-shielding mask,
7. The exposure method according to claim 6, wherein the exposure is performed based on design data of the light shielding mask.