JPH04100049A - X-ray exposing method and device - Google Patents

Abstract

PURPOSE:To reduce the irregularity of the intensity of a transmitted X-ray and to forme a pattern with high accuracy by finely reciprocating a Be thin film in the process of exposure. CONSTITUTION:A radiated light beam 7 being fetched from a charged particle accumulation ring is reflected by a total reflection mirror 8 to remove the short wavelength component thereof, and further the long wavelength component thereof is removed by the Be thin film 9, so that only the X-ray 13 having 5-15Angstrom wavelength is transmitted. A wafer 12 is exposed by using the X-ray 13, and the Be thin film 9 is finely reciprocating from right to left in the process of the exposure. Since the front and the back of the Be thin film 9 are supported to a vacuum duct 14 by two bellows 15 and 16, it is easy to move in parallel with the surface of the film. By finely reciprocating the Be thin film 9 from right to left in the process of the exposure, the unevenness of the thickness of the Be thin film and the irregularity of the intensity of the X-ray caused by surface roughness are reduced, thereby removing the irregularity of the exposure.

Description

[Detailed Description of the Invention] [Summary] Regarding an X-ray exposure method and exposure apparatus using synchrotron radiation, the purpose of this is to prevent unevenness in the intensity of X-rays irradiated to a resist. In an X-ray exposure method in which X-rays transmitted through a thin film are used to expose a resist, the beryllium thin film is configured to repeatedly move back and forth slightly to the left and right during exposure.

[Industrial application field]

The present invention relates to an X-ray exposure method and exposure apparatus using synchrotron radiation.

In recent years, semiconductor devices have become denser and their patterns have become finer. For this reason, in the photolithography process during manufacturing, there is a limit to the resolution of exposure using visible light, so recently, X-rays with a much shorter wavelength than visible light have been used. Regarding X-ray exposure methods, methods using synchrotron synchrotron radiation are being studied, and compared to methods using conventional X-ray tubes, the X-ray intensity is higher, which improves throughput, and the out-of-parallel radiation is higher. Therefore, it is attracting attention because it allows for finer pattern transfer without penumbra blur.

[Conventional technology]

FIG. 3 is a diagram showing the principle of a synchrotron radiation generator. In the figure, 1 is an injector, 2 is a charged particle storage ring consisting of a deflection magnet 3, a high-frequency cavity 4, and a vacuum duct 5, and 6 is an outlet for synchrotron radiation 7. The charged particles entering the charged particle storage ring 2 from the injector 1 are deflected in their traveling direction by the deflection magnet 3 and circulate within the charged particle storage ring 2, and a high frequency voltage is applied in synchronization with the rotation of the charged particles. Energy is given each time the beam passes through the high-frequency cavity 4, and synchrotron radiation is finally generated.

Since this emitted light is not deflected by the magnet, it is extracted from the emitted light extraction port 6 in the deflection magnet section 3. This synchrotron radiation 7 has a wide wavelength range from X-rays to far infrared rays, but the wavelength range used for X-ray exposure is 5 to 15 wavelengths. X-ray exposure equipment that uses these X-rays includes:
As shown in FIG. 4, a window is provided with a total reflection mirror 8 of t to remove short wavelength components and a beryllium thin film 9 of t to remove long wavelength components. X-rays 13 enter an exposure stepper 10 and pass through a mask 11 to expose a wafer 12.

Note that since this X-ray beam 13 has a horizontally elongated shape, the mask 11 and the wafer 12 move together in the vertical direction and are scanned.

[Problem to be solved by the invention]

In the conventional X-ray exposure apparatus described above, when synchrotron radiation passes through the beryllium thin film 9, the beryllium thin film 9
Due to the thickness unevenness and surface roughness of the X-rays 13, intensity unevenness occurs in the transmitted X-rays 13. Since the wafer 12 and the mask 11 are integrally scanned in the vertical direction, the intensity of the X-rays irradiated to the resist coated on the wafer 12 is uniform in the vertical direction.

However, since it does not scan in the horizontal direction, uneven X-ray intensity causes uneven irradiation of the resist, and in the horizontal direction, there is a problem that high-precision pattern formation is not possible due to changes in the pattern due to uneven doses and changes in the amount of remaining film. There is.

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide an X-ray exposure method and an X-ray exposure apparatus that prevent unevenness in the intensity of X-rays irradiated onto a resist.

[Means to solve the problem]

In order to achieve the above object, the X-ray exposure method of the present invention includes:
The X-ray exposure method utilizes X-rays transmitted through the beryllium thin film 9 from synchrotron radiation to expose the resist, and is characterized in that the beryllium thin film 9 is repeatedly slightly moved back and forth from side to side during exposure.

Further, in the X-ray exposure apparatus of the present invention, in an X-ray exposure apparatus that utilizes X-rays transmitted through the beryllium thin film 9 from synchrotron synchrotron radiation to expose a resist, the beryllium thin film 9 is arranged in front and behind the bellows. 15 and 16, it is attached to and supported by the vacuum duct 14, and is characterized in that it is provided with a driving means that can slightly move the beryllium thin film from side to side.

[For production]

By repeatedly slightly moving the beryllium thin film 9 to the left and right, which transmits X-rays from synchrotron radiation, the intensity unevenness of the transmitted X-rays due to uneven thickness and surface roughness of the beryllium thin film 9 is averaged, and the intensity of the transmitted X-rays to the wafer 12 is Irradiation unevenness is eliminated.

〔Example〕

FIG. 1 is a diagram for explaining the X-ray exposure method of the present invention.

In the figure, 2 is a charged particle storage ring of a synchrotron radiation light generating device, 7 is a synchrotron radiation beam taken out from the charged particle storage ring, and 8 is a synchrotron radiation beam for removing short wavelength components from the synchrotron radiation light. Reflection mirror 9 is a Be thin film for excluding long wavelength components, 11 is a mask, and 12 is a wafer coated with resist.

In such an X-ray exposure apparatus, in the X-ray exposure method of the present invention, while exposing the wafer 12 with X-rays 13,
The Be thin film 9 is repeatedly moved back and forth slightly to the left and right (in the directions of arrows x and x'). The fine movement conditions may be, for example, a fine movement width of about 5 mm, a reciprocation period of IHz, and an exposure time of 10 minutes.

By exposing in this way, even if the X-rays 13 transmitted through the Be thin film 9 have uneven intensity due to uneven thickness or surface roughness of the Be thin film 9, the intensity unevenness is averaged out due to the reciprocating movement of the Be thin film. and average exposure. This enables highly accurate pattern formation.

FIG. 2 is a diagram showing an embodiment of the X-ray exposure apparatus of the present invention.

In the figure, 7 is synchrotron radiation taken out from the charged particle storage ring, 14 is a vacuum duct that guides the synchrotron radiation to the exposure position, and 8 is total reflection for removing short wavelength components from the synchrotron radiation. mirror, 15
．． 16 is a bellows installed in the vacuum duct, 9 is a synchrotron radiation light that removes long wavelength components, and X-rays (wavelengths 5 to 1).
5 people), and the Be thin film 9 transmits 2
It is arranged between the two bellows 15 and 16, and is driven left and right by a drive device, for example, a pulse motor (arrows X-X'
It is designed to be driven back and forth between the two directions. Further, 10 is an exposure stepper that accommodates a mask 11 and a wafer 12, and its housing is connected to a vacuum duct 14.

In this embodiment configured in this way, the emitted light 7 taken out from the charged particle storage ring is reflected by the total reflection mirror 8 to remove the short wavelength component, and further, the long wavelength component is removed by the E3e thin film 9. Only X-rays 13 with wavelengths of 5 to 15 are transmitted. The wafer 12 is exposed to the X-rays 13, and during the exposure, the Be thin film 9 is slightly moved back and forth from side to side. Since the Naori e thin film 9 is supported by the vacuum duct 14 by two bellows 15 and 16 at the front and back,
It is easy to move parallel to the film surface (however, there is a limit to the movement width).

As described above, in this embodiment, by slightly moving the Be thin film 9 back and forth in the left and right directions during exposure, unevenness in the X-ray intensity due to unevenness in the thickness of the Be thin film and surface roughness is reduced, thereby eliminating exposure unevenness. be able to.

〔Effect of the invention〕

As described above, according to the present invention, by slightly moving the Be thin film back and forth during exposure, it is possible to reduce the intensity unevenness of transmitted X-rays, contributing to more accurate pattern formation.

[Brief explanation of drawings]

Fig. 1 is a diagram illustrating the X-ray exposure method of the present invention, Fig. 2 is a diagram showing an embodiment of the X-ray exposure apparatus of the present invention, and Fig. 3v! : I is a diagram showing a conventional synchrotron radiation light generating device, and FIG. 4 is a diagram showing a conventional X-ray exposure device. In the figure, 2 is a charged particle storage ring, 7 is synchrotron radiation, 8 is a total reflection mirror 9 is a Be thin film, 10 is an exposure stepper 11 is a mask, 12 is a wafer 13 is an X-ray, 14 is a vacuum duct, 15. 16 indicates a bellows. Diagram for explaining the X-ray exposure method of the present invention. Figure 3 showing the light generating device

Claims (1)

[Claims] 1. In an X-ray exposure method in which X-rays from synchrotron radiation transmitted through a beryllium thin film (9) are used to expose a resist, the beryllium thin film (9) is repeatedly moved back and forth from side to side during exposure. An X-ray exposure method characterized by slight movement. 2. In an X-ray exposure device that uses X-rays from synchrotron radiation that have passed through the beryllium thin film (9) to expose the resist, the beryllium thin film (9) is exposed to the bellows (15, 16) placed before and after the beryllium thin film (9). X characterized by being provided with a driving means that is attached to and supported by the vacuum duct (14) and that can slightly move the beryllium thin film from side to side.
Line exposure equipment.