JPS6197832A - X-ray exposure device - Google Patents

Abstract

PURPOSE:To enable repetition transcription of high throughput and small shift and small obscurity by a method wherein an X-ray reflector which determines the exposure area is installed at an angle whereby X-ray beams are totally reflected, in an X-ray beam radiated from the target. CONSTITUTION:A target 11 is irradiated with electron beams 9 emitted from an electron gun 8, and soft X rays 12 of wavelength 8.34Angstrom generate. Part of this X-ray is made incident into the plane of a total reflection plate 16, and the other is adsorbed by a disc-shaped absorption plate 17. The total reflection plate 16 is installed 30cm below the target so as to be a total reflection plate 18 for the soft X-ray emitted from the right end 14 of an electron beam spot. For example, totally reflected soft X ray comes into a mask 22 with an angle 21 of 3.18 deg. to the vertical direction. With respect to the reflected light at each position on the total reflection plate 16, the total reflected light at the lower end 23 of the total reflection plate 16 spreads by an angle 24 of 3.53 deg. to the vertical direction. Since soft X rays due to total reflection thus spread only outward, obscurity caused by the soft X ray irradiating the mask does not generate, but only the shift at the mask ends generates.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an X-ray exposure apparatus.

Conventional Structures and Their Problems Traditionally, optical exposure has been used to manufacture semiconductor integrated circuits, but as elements become smaller, a problem has arisen in which resolution is reduced due to the single-diffraction effect of light interference.

Therefore, electron beam and X-ray exposure methods were developed.

However, since the electron beam uses a direct writing method on the wafer, the exposure time is long and it is not economical. On the other hand, a method using soft X-rays with several wavelengths to several tens of wavelengths is cheaper and has higher throughput than the method using an electron beam. In conventional soft X-ray exposure, as shown in FIG. 1, an electron beam 2 emitted from an electron gun 1 is applied to a target 3 to generate soft X-rays 4. For soft X-rays, a mask 6 consisting of a soft X-ray transmission layer and an absorption layer is used.
The soft X-rays incident on and transmitted through the photosensitive layer 7 on the semiconductor substrate 6
was exposed to light and the pattern was transferred. In this method, the second
As shown in the figure, if the distance between the target 3 and the semiconductor substrate 6, the distance g between the mask 6 and the semiconductor substrate 6, the diameter of the semiconductor substrate 6 is d, and the diameter of the electron beam is S, then "Misalignment" Δ is Δ=dg/2D and "blur"
δ becomes δ=gs/D. That is, since both Δ and δ vary in proportion to the distance g between the mask 6 and the semiconductor substrate 6, “warpage” and “distortion” of the substrate have a large influence.

Therefore, it is difficult to reduce both "shift" and "blur" in the batch exposure of X-rays.

On the other hand, it has been proposed to reduce the "shift" by repeatedly exposing small areas using soft X-rays near the center of the radiation, but this method reduces the "shift" at the edges. However, it is not possible to reduce the blur. Also soft X
Since the center of the line is used, only one substrate can be processed with one light source, resulting in low throughput.

Purpose of the Invention The present invention is intended to solve this problem.The purpose of the present invention is to utilize total internal reflection of soft X-rays to enable repeated transfer with high throughput and small "shift" and "blur". This is an X-ray exposure device.

Structure of the Invention The present invention provides an X-ray beam emitted from a target.
An X-ray exposure apparatus characterized in that an X-ray reflector that determines the exposure area is installed at an angle where the X-ray beam is totally reflected, and the totally reflected xH beam is used to perform exposure at the same magnification. As a result, it is possible to realize a highly parallel X-ray beam over a wide range, and by using this, exposure processing of multiple substrates can be performed simultaneously.

DESCRIPTION OF EMBODIMENTS Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 3 is a cross-sectional view of the device.

The electron beam 9 emitted from the electron gun 8 has a beam spot diameter of 1
Irradiate target 11 with 04ff7ff, m, wavelength 8
．． Soft X-rays 12 are generated for 34 people. The electron beam has an accelerating voltage of 30KV and a beam current of 4 people. The soft X-rays are emitted from between the left end 13 and the right end 14 of the beam spot cross section within an angle 15 of 4.28° with respect to the vertical direction.
A part of the generated soft X-rays is incident on the plane of total reflection 16, and the other part is absorbed by disk-shaped absorption plate 17.

The total reflection plate 16 was a stainless steel plate with a width of 2CIR and a length of 5°1 coated with 1 μm of gold. Absorption plate 17
A stainless steel disk with a radius of 15 mm was coated with 1 μm of gold. The total reflection plate 16 is installed 30 m below the target so that the total reflection angle is 18 for the soft X-rays emitted from the right end 14 of the electron beam spot. That is, since the total reflection angle of gold is 0.55°, the total reflection plate 16 was installed at an angle 19 of 3.73° with respect to the vertical direction. Therefore, the angle of incidence of all soft X-rays incident on the total reflection plate 16 is 0.55° or less, so that all of the incident X-rays are reflected. FIG. 4 shows a graph of total reflection angles for soft X-rays for each metal. Alternatively, an X-ray reflector other than the total reflection plate 16 can be used. The soft X-rays totally reflected by the upper end 2Q of the total reflection plate 16 enter the mask 22 at an angle 21 of 3.18° with respect to the vertical direction. Furthermore, the total reflection light at each position on the total reflection plate 16 is 3 times the total reflection light at the lower end 23 of the total reflection plate 1e in the vertical direction.
．． Spread by 24 angles of 53°.

In this way, the soft X-rays due to total reflection spread only outward, so that "blurring" due to the soft "H" irradiated onto the mask does not occur, but only "shifting" at the edge of the mask occurs.

The "shift" due to the soft X-rays totally reflected at the lower end 23 of the total reflection plate 16 is the largest, but under the present experimental conditions, the batch exposure? The "deviation" in the case of this method is 0.638 μm, whereas in this method it is 0.31 μm. Further, the exposure area at this time is determined by the width and length of the total reflection plate, and further determined by the soft X-ray emission angle from the target. In this experiment, 20 excitation
It has a 4-light area of 6 horses. Using this exposed area, the entire lower substrate is moved and exposed repeatedly. Furthermore, since the exposure area can be increased by the number of total reflection plates, a plurality of areas can be exposed with one light source.

Effects of the Invention As detailed above, the present invention provides a dielectric plate that determines the exposure area in the X-ray beam emitted from the target, and is installed at an angle where the X-ray beam is totally reflected. This is an X-ray exposure apparatus that uses a beam to repeatedly perform exposure at the same magnification, and by using the present invention, X-ray exposure with high throughput and small "shift" without "blur" can be performed.

[Brief explanation of drawings]

Figure 1 is a schematic layout of a conventional X-ray exposure device, and Figure 2 is an X-ray exposure device.
Element layout diagram explaining "shift" and "blur" due to ray exposure, Figure 3 is a sectional view of the X-ray exposure equipment layout explaining the present invention in detail, Figure 4 shows the atomic weight of metals and total reflection for soft X-rays. It is a graph showing the relationship between angles. 1...electron gun, 2...electron beam, 3
...Target, 4...Soft X-ray, 5.
...Mask, 6...Semiconductor substrate, 7...
...Photosensitive layer, 8...Electron gun, 9...
・Electronic game, 10...Spot diameter, 11...
...Target, 12...Soft X-ray, 13.
...Beam spot left end %14...Beam spot right end, 16...Angle of 4.28°,
16... Total reflection plate, 17... Absorption plate,
18... Total reflection angle, 19...3,73
Angle of °, 20... Upper end of total reflection plate, 21...
...3.18° angle. 22...Mask, 23...Lower end of total reflection plate, 24...Angle of 3.63°. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4: Scraps!

Claims (1)

[Claims] In the X-ray beam emitted from the target, an X-ray reflector that determines the exposure area is installed at an angle where the X-ray beam is totally reflected, and the totally reflected X-ray beam is used to expose the same size. An X-ray exposure device characterized by performing the following.