JPH0748080B2 - Synchrotron radiation transparent window - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention uses a synchrotron radiation to transmit the radiation of an exposure apparatus that transfers a circuit pattern of a VLSI or the like onto an exposed plate-like object such as a wafer. Regarding windows

[Conventional technology]

With the progress of highly integrated semiconductor (LSI) technology, the use of synchrotron radiation including soft X-rays is attracting attention even in a semiconductor lithography apparatus that transfers a pattern on a mask onto a wafer to which a resist is attached. It became so.

As shown in FIG. 3, this emitted light is emitted in the tangential direction of the electron orbit when an electron having a speed close to the speed of light is bent by the magnetic field of the deflection magnet (101) in the high vacuum electron storage ring (100). The electromagnetic waves generated by the X-ray exposure apparatus transfer the mask pattern of the VLSI having a line width of quarter micron class to the plate-like object to be exposed because it has good parallelism and strong soft X-rays can be obtained. It is expected as the next X-ray source.

In an actual exposure apparatus using the synchrotron radiation,
Radiation light emitted from the electron storage ring (100) is guided into the transfer device (102) through the beam line (3), and inside the transfer device (102), an X-ray mask (not shown), a wafer drive stage (not shown), etc. The mask pattern is transferred onto the surface of the plate-like object to be exposed (in this case, the resist coated on the wafer) using various devices.

Of these, the inside of the beam line (3) is kept vacuum so as not to adversely affect the high vacuum state in the electron storage ring (100), while the transfer device (102) is
In order to suppress the temperature rise of the mask, the periphery of the mask is surrounded by a chamber (103) and the inside is filled with the atmosphere or another gas atmosphere (helium gas or the like having a small radiant light attenuation effect). Therefore, between the radiation source side (in the figure, the electron storage ring (100) and the beam line (3)) that emits synchrotron radiation and the transfer device (102), a high vacuum on the radiation source side is provided on the way of the radiation light path. A radiant light transmitting thin film (4) such as a beryllium thin film capable of transmitting a part of radiant light is provided so as to separate the region from the atmosphere on the transfer device (102) side.

[Problems to be solved by the invention]

FIG. 4 is a cross-sectional view showing a conventional example of a radiation transmitting window having such a radiation transmitting thin film (4) attached thereto. As shown in the figure, an end wall surface is constituted by the mounting frame (30) provided at the end of the beam line (3), and the radiant light transmitting thin film (4) is installed in the opening of the mounting frame (30). Is clamped around the mounting frame (30) by the retainer (31),
It is fixed with a presser screw (32). The mounting frame (30) in the figure is fixed to the beam line (3) by a beam line mounting screw (33) so that the atmosphere on the extraction side does not leak.

The radiant light transmitting thin film (4) is usually composed of a beryllium film or the like, and plays the role of extracting the soft X-ray component of the synchrotron radiated light guided thereto to the outside.

On the other hand, at the time of exposure, while aligning the radiant light optical path and the radiant light transmissive thin film (4) so that the portion having the highest radiant light intensity passes through the radiant light transmissive thin film (4), the aligner of the aligner is aligned. Although installation and attitude control are performed, the optical path of the radiated light at that time can be confirmed and its intensity sensed only by using an X-ray detector or by actually exposing the resist surface. Had to be actually replaced with a high-purity helium atmosphere (in the air, the optical path was attenuated to 2 mm to reach 0), and it was difficult to finish the axis alignment / posture control in a short time.

The present invention has been made in view of the above problems of the prior art, by improving the configuration of the radiant light transmission window, the alignment and attitude control can be performed with the naked eye or a visible light sensor instead thereof, and in that case It is another object of the present invention to provide a configuration capable of easily detecting the deviation of the optical axes in the horizontal direction and the vertical direction.

[Means for solving problems]

Therefore, the radiant light transmitting window of the present invention is basically characterized in that the radiant light transmissive thin film provided on the wall surface of the end portion of the beam line is in the center, and two or more peripheral portions in the horizontal direction are visible light transmissive portions. .

If an optical component made of quartz, sapphire, or the like is used for the visible light transmitting portion, the radiant light component that passes through this portion is only visible light, and the soft X-ray component is not transmitted.

Further, in the second invention, in addition to the above-mentioned structure, the radiant light transmitting thin film and the visible light transmitting portion are respectively provided with shutters capable of opening and closing (incident or blocking of radiant light) simultaneously or separately.

By providing such a shutter structure, it is possible to prevent unnecessary radiation light leakage by closing the radiation light transmission thin film or the visible light transmission portion when the radiation light need not be transmitted.

[Action]

In the above-mentioned structure, the visible light transmitting portion provided in two or more horizontal positions around the radiation light transmitting thin film in the middle transmits the visible light component of the synchrotron radiation, and the radiation is emitted while observing the radiation with the naked eye. Since it is possible to align the optical path with the synchrotron radiation thin film and control the attitude of the aligner, it becomes possible to detect the vertical deviation of the synchrotron radiation optical path and to sandwich the radiant light transparent membrane. From the comparison of the radiant light intensities on both sides, it is possible to know the relative displacement in the horizontal direction of the radiant light optical axis with respect to the transfer device side.

〔Example〕

 Specific examples of the present invention will be described below.

FIG. 1 is a structural explanatory view of a radiant light transmission window according to the second invention of the present application. In the figure, (3) is the beam line, (30) is the mounting frame,
(4) is a radiation transparent thin film made of beryllium film, (31)
Is a holding metal fitting, (32) is a holding screw, and (33) is a beamline mounting screw, which have exactly the same configuration as described above.

In this embodiment, two openings are provided in a mounting frame (30) on a horizontal line that crosses the central portion of the radiant light transmissive thin film (4), and optical parts (1a) (1b) made of quartz are fitted therein and airtight. By fixing, the visible light transmitting portion is formed.

Further, on the transfer device (not shown) side of the mounting frame (30), there are visible shutters (2a) for the visible light transmitting portion that are independently opened and closed by rotary solenoids (20) (21), and for the soft X-ray transmitting portion. A shutter (2b) is provided for each of the shutters (2a), for entering and blocking of the radiant light transmitted through the optical components (1a), (1b), and for the shutter (2b), the radiant light transmitting thin film (4). ).

As in the present embodiment, the visible light transmitting portion is provided in the horizontal direction around the radiant light transmitting thin film (4) so that the synchrotron radiation emitted from the electron storage ring is flat in the horizontal direction. Therefore, even if there is a slight vertical deviation in the optical path of the emitted light, it becomes possible to detect it immediately. The visible light transmitting parts are provided on both sides of the radiant light transmitting thin film (4) because the horizontal axis can be aligned by adjusting the intensity of the radiated light detected from the visible light transmitting parts to be equal. Is.

In this embodiment, as a preparatory work before the X-ray exposure is performed using the synchrotron radiation emitted from the beam line (3) through such a radiation transmission window structure, the optical path of the radiation is used. And the synchrotron radiation transmitting window structure (in particular, the synchrotron radiation transmitting thin film (4)) were aligned. At this time, the shutter (2a) was opened and the other shutter (2b) was closed so that only the visible light component of the synchrotron radiation could be taken out to the transfer device side.

In such a state, if there is no vertical deviation in the optical path of the synchrotron radiation from the radiation-transmissive thin film (4), from the visible light transmission part consisting of the above-mentioned optical components (1a) (1b). The visible light component of the emitted light will be extracted,
If there is any deviation in the vertical direction than that, the emitted light cannot pass through it, so this entire emitted light transmitting window configuration is kept until the emitted light can be detected by the naked eye from the visible light transmitting portion. It is moved in the vertical direction (if there is a radiation reflection mirror in the beam line (3), it is rotated), and its axis alignment is performed (in the case of a radiation reflection mirror, the With the position determined by the axis alignment as the center of rotation during exposure, the mirror is oscillatedly rotated. If a visible light intensity sensor (not shown) is used to detect the emitted light from the two visible light transmitting portions, the horizontal shift between the two can be known from the intensity comparison of both emitted light. It becomes possible to perform the horizontal axis alignment after performing the directional axis alignment. As a result, the radiant light transmissive thin film (4) in the middle of the two visible light transmissive parts is automatically irradiated with the portion having the strongest radiant light intensity.

If the shutter (2a) is closed and the shutter (2b) is opened after such axis alignment work, the X-ray exposure work will be started.

In addition, FIG. 2 is a horizontal sectional view showing another embodiment of the present invention.

In the figure, optical components (12a) and (12b) are provided at the same positions as in the first embodiment (that is, in the horizontal direction) to form a visible light transmitting portion. One of the components (12a) is a lens. However, each of the other parts (12b) is shown to be constructed by using a pinhole plate or a quartz glass plate with a mark such as a crossed wire.

〔The invention's effect〕

According to the configuration of the synchrotron radiation transmitting window of the present invention described in detail above, when aligning the synchrotron radiation optical path and the synchrotron radiation transmitting thin film, when performing the attitude control of the aligner, or when illuminating visible light for alignment or the like. When using, the visible light component of the radiated light transmitted through the visible light transmitting portions provided at two or more horizontal positions around the radiant light transmitting thin film in the middle is observed with the naked eye or a TV monitor. However, since the above-mentioned axis alignment and attitude control are performed, it becomes possible to detect the vertical deviation of the emitted light optical path at that time, and from the comparison of the emitted light intensities on both sides of the emitted light transmitting thin film, the transfer device side It is possible to know the relative shift of the optical axis of the emitted light in the horizontal direction.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of the second invention of the present application, FIG. 2 is a horizontal sectional view showing another embodiment, and FIG. 3 is a structure of an X-ray exposure apparatus using synchrotron radiation. Schematic,
FIG. 4 is a sectional view showing a conventional structure of the radiant light transmission window. In the figure, (1a) and (1b) are optical components, (10) is a mounting frame, and (1
1) is an inner plate, (12a) is a lens, (12b) is a quartz glass plate, (2a) and (2b) are shutters, (3) is a beam line,
Reference numeral (4) denotes a radiant light transmitting thin film.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05G 1/00 2/00 H05H 13/04 U 9014-2G H05G 1/00 G

Claims (2)

[Claims] 1. A radiant light transmitting window characterized in that a radiant light transmissive thin film provided on a wall surface of an end portion of a beam line is formed in the center, and two or more peripheral portions in the horizontal direction are visible light transmissive portions. 2. The radiant light transmitting thin film provided on the wall surface of the end portion of the beam line is formed in the center, and two or more peripheral portions in the horizontal direction are visible light transmitting portions, and the radiant light transmitting thin film and the visible light transmitting portion are provided. A radiant light transmitting window, characterized in that each of them is provided with a shutter capable of opening and closing them simultaneously or separately.