JPH03211817A - Exposure aligner - Google Patents

Abstract

PURPOSE:To realize the short time exposure of a pattern whose line width is 0.4mum or less, by constituting an aligner by using a spiral orbit type undulator inserted into an electronic storage ring, and an exposing chamber provided with a reflection optical system which performs demagnification projection applying the undulator radiation generated from the undulator to a light source. CONSTITUTION:The title aligner is constituted of the following; a spiral orbit type undulator 10 inserted into an electronic storage ring 11, and an exposing chamber provided with a reflection optical system which performs demagnification projection applying the undulator radiation generated from said undulator 20 to a light source. The undulator radiation 20 is projected on a wafer 25 by a Schwarzschild's reflecting mirror 24, after being vertically reflected by a reflecting mirror 21 and passing a reticle 22. A pattern on the reticle 22 is reduced to be about 1/4 and forms an image on the wafer 25. Thereby an aligner capable of the short time exposure of a pattern whose line width is 0.4mum or less can be obtained.

Description

[Detailed description of the invention] [Industrial application field 1 This invention relates to semiconductor integrated circuits and printed circuits.

Regarding phosphorography technology in the manufacturing process of optical devices (diffraction gratings, waveguides) and ultrasonic devices, etc., we particularly use short-wavelength, high-intensity undulator radiation generated from high-speed electron beams using a spiral orbit type electronic meandering device (undulator) as a light source. The present invention relates to an exposure apparatus equipped with a reflective optical system that reduces and projects a pattern onto an optical system using light.

[Conventional technology]

FIG. 4 is a block diagram showing an example of a conventional exposure apparatus, in which 1 is a mercury lamp, 2 is an illumination lens, 3 is a reticle, 4 is a projection lens, 5 is a wafer, and 6 is a stepper.

In the above conventional exposure apparatus used for photolithography of semiconductor integrated circuits, an ultra-high pressure mercury arc lamp or a xenon/mercury arc lamp is used as the mercury lamp 1 as a light source. In the case of mercury lamp 1, the spectral lines used for exposure are mainly g-line (wavelength 435.8 nm) and h-line.
This is ultraviolet ray (404°7 nm), and reduction projection exposure using i-line (365 nm) is being considered to aim for even shorter wavelengths. Generally speaking, reduction projection is performed by creating a 5 to 10 times enlarged version of the actual pattern called a reticle 3 (original version of the IC circuit pattern), as shown in Figure 4, and using a lens system to project the reduced pattern onto the wafer 5. This method involves exposing the resist to light. The reticle 3 usually has a pattern including several chips, which are successively exposed onto the wafer 5 by a stepper 6. Therefore, this entire device is abbreviated as a stepper.

[Problem to be solved by the invention 1 However, in the conventional phosphorography technology, the reticle 3
Since a fine pattern drawn on the surface is projected by the illumination lens 2, if the pattern becomes too fine, blurring (diffraction) of the same degree as the wavelength of the light used for pattern transfer will occur. Therefore, as patterns become finer, the wavelength of the light used must also be made shorter. Currently, a mercury lamp 1 is used for exposure, and its wavelength is about 0.4 μm. Therefore, this light cannot be used for ultra-super LSIs with a line width of about 0.5 μm or less. Therefore, as light with a shorter wavelength (11 m wave), for example, x #j is generated in an excimer laser (0.193 μm in the case of ArF), an X-ray tube, or the bending electromagnet part of an electron storage ring.
Attempts have been made to utilize synchrotron radiation (electromagnetic waves) in region A, but
In the case of excimer lasers, problems such as the duration of continuous oscillation have been pointed out. Regarding X-ray synchrotron radiation, it is necessary to create a fine pattern on a mask (corresponding to reticle 3 in Fig. 4) with the same dimensions as the pattern on wafer 5 because it is an isometric beam, and mask pattern fabrication is required. becomes difficult. In addition, X-ray irradiation has problems such as radiation damage on the mask and heat load that distorts the pattern.

This invention was made to solve the above conventional problems, and uses a spiral orbit type undulator as a stable light source with high brightness in the deep ultraviolet and vacuum ultraviolet regions, and reduces and projects patterns using a reflection optical system. The object of the present invention is to obtain an exposure apparatus that can expose a pattern with a line width of 0.4 μm or less in a short time.

[Means for Solving the Problems] An exposure apparatus according to the present invention includes a spiral trajectory undulator inserted into an electron storage ring, and a reflection optical system that uses the undulator radiation light generated from the spiral trajectory undulator as a light source to reduce and project the light. It consists of an exposure chamber equipped with.

[Operation] In the present invention, the undulator radiation light generated from the spiral orbit type undulator is used, and the pattern is reduced and projected with a reflecting mirror, thereby showing a configuration of 0.4 urator. In these figures, 10 is a spiral orbit type undulator, 11 is an electron storage ring, 12 is an exposure chamber, 13 is a synchrotron radiation extraction window, 14 is a bending electromagnet, and 15
16 is a quadrupole magnet, 16 is a high frequency acceleration cavity that adds energy to the stored electron beam, 17 is an inflector 18 is a converter, 19 is a linear accelerator that makes the electron beam enter the electron storage ring 11, 20 is undulator synchrotron radiation, 21 is a reflector, 22 is a reticle (mask),
Reference numeral 23 denotes a reticle stage, and 24 denotes a Schwartschild type reflecting mirror, which consists of a convex surface m 24 a and an annular concave mirror 24b, and the light reflected by the convex mirror 24a is reflected by the concave mirror 24b to form an image on the wafer. 25 is a wafer, 26 is a step stage, 27 is an electron beam, and 28 is a permanent magnet array.

Next, the operation will be explained.

By using the undulator synchrotron radiation 2o as a light source, high brightness can be easily achieved in the far ultraviolet and vacuum ultraviolet regions. The spiral orbit type undulator 10 is a quasi-monochromatic light source that rotates passing high-speed electrons many times to interfere with a specific wavelength.

The spiral orbit type undulator 10 formed with the permanent magnet array 28 as shown in FIG. 2 can obtain high-intensity light because the electrons constantly emit electromagnetic waves. By appropriately changing the magnetic field and the magnet array, electrons can be made to travel on various orbits. [Densokken News No. 462 (July 1988), Polarization generator: Patent application No. 137655, 1988, H, 0n
Polarizing undul by ukiet al
ator with cross and ret
arded magnetic fields:R
ev, Sci, Instru-m, Vol, 60 (19
89) pp. 1838], which facilitates homogenization of the light intensity on the illuminated surface.

A spiral orbit type undulator 10 is inserted into the straight part of the electron storage ring 11. The periodic length of the magnetic field is 7°6cm, the number of periods is 39, and the peak strength of the JI field is 1.4KG (6cm gap between opposing magnet rows), and the peak strength is 150nm (0.15μm) from the accumulated electrons of 370MeV as shown in Figure 3. An undulator radiation light 20 having the following values is obtained. This peak wavelength can be changed by changing the electron energy. (2
In the case of use below 0On, m, the exposure chamber 12 is replaced with air by a rare gas, etc.). This undulator radiation 20 is guided to the exposure chamber 12 through a radiation extraction window 13 made of MgF2. The undulator radiation light 2o is reflected vertically by a reflecting mirror 21, passes through a reticle 22, and then passes through a Schwartschild type reflecting mirror 24.
is projected onto the wafer 25 by. The pattern on the reticle 22 is reduced to about 1/4 and is imaged onto the wafer 25. Furthermore, exposure with a line width of 0.4 μm or less is possible. A spiral track type undulator with a total length of 3 m has an accumulated current of 25
At 0 mA, one exposure can be performed in about 1 second.

[Effect of the Invention 1 As explained above, the present invention includes a spiral orbit type undulator inserted into an electron storage ring, and a reflection optical system that uses the undulator radiation light generated from the spiral orbit type undulator as a light source to reduce and project it. Since it consists of an exposure chamber, exposure of a pattern with a line width of 0.4 μm or less can be realized in a shorter time than conventionally. Reticle (mask)
can be manufactured using conventional techniques, and conventional resist materials can be used, so there is no need to develop new masks and resists. By using a spiral orbit type undulator as a light source, the brightness is higher than that of a conventional planar type undulator, so the straight part of the electron storage ring can be short. Further, since the generation of harmonics from the electrons in the spiral orbit is small, there is an advantage that the deterioration of the MgF2 window for extracting the synchrotron radiation from the electron storage ring can be minimized.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show an embodiment of the present invention. FIG. 1(a) shows the entire exposure apparatus and the configuration of the linear accelerator, and FIG. Figure 1(a) is a diagram showing the configuration of the main optical system of the exposure chamber, Figure 2 is a diagram showing the configuration of the spiral orbit type undulator used in the exposure apparatus of Figure 1, and Figure 3 is a diagram showing the configuration of the undulator-radiated light. FIG. 4, which is a diagram showing a spectrum, is a configuration diagram showing an example of a conventional exposure apparatus. In the figure, 10 is a spiral orbit type undulator, 11 is an electron storage ring, 12 is an exposure chamber, 13 is a synchrotron radiation extraction window, 17 is an inflector, 19 is a linear accelerator, 20 is an undulator synchrotron radiation, 21 is a reflecting mirror, 22 is the reticle,
23 is a reticle stage, 24 is a Schwartschild type reflector, 25 is a wafer, and 26 is a step stage. Figure 1 N O Anonyu Shirisa J Lamp Source Figure 2 Figure 3 Cod Wavelength (nm) 7 Figure

Claims (1)

[Claims] An exposure apparatus comprising: a spiral orbit type undulator inserted into an electron storage ring; and a reflection optical system that uses the undulator radiation light generated from the spiral orbit type undulator as a light source to reduce and project the radiation.