JPS5950216B2 - X-ray exposure device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray exposure apparatus having high precision and processing capacity.

A conventional X-ray exposure apparatus is shown in FIG.

A is an X-ray light source, 1 is an electron gun, and 2 is a target, which irradiates the target 2 with an electron beam 3 from the electron gun 1. As a result, X-rays 4 are generated. 5 is a vacuum chamber that keeps the electron gun 1 and target 2 in a high vacuum; 6
is a window provided in the vacuum chamber 5 for taking out the X-rays 4.

7 is a mask having an X-ray absorber pattern on an X-ray transparent thin film, and 8 is a wafer whose surface is coated with a resist that reacts with X-rays. They are held with a gap of several tens of μm.

Generally, prior to exposure, it is necessary to align the pattern on the mask 7 and the pattern on the wafer 8.

10 is a mark detection device for this purpose, 11 is an alignment control device, and 12 is an XYθ stage. Send to 11.

The alignment control device 11 receives the signal sent from the mark detection device 10, calculates the amount of positional deviation, and sends a control signal to the XYθ stage 12, so that the XYθ stage 12 moves. When alignment is completed with a predetermined accuracy in this manner, the mask and wafer are fixed and exposed to X-rays.
In X-ray exposure, as shown in Figure 2, the mask and wafer are placed in contact to prevent defects in the patterns on the mask and wafer due to contact, and because the wavelength of X-rays is short, the pattern is blurred due to diffraction. Because it is small, from several μm to several 1
It is held with a gap Sb of 0ltm.

Furthermore, unlike visible light, X-rays cannot be focused to obtain a parallel beam of light, so diverging light from a point light source is used. For this reason, as shown at 21 in FIG. 2, image deviation occurs toward the periphery of the wafer. Furthermore, since the actual light source has a large size, it produces a penumbra as shown at 22 in FIG. 2'.

The shadow and penumbra of this image are as follows, assuming that the distance between the light source and the mask is Ba, the distance between the mask and the wafer is Sb, the radius of the light source is d, and the radius of the wafer is D, as shown in FIG.
5 Image escape = D'Sb.

1=2d-5b Therefore, in order to perform highly accurate pattern transfer, it is necessary to reduce both the image deviation and the penumbra.

Therefore, the distance Sa between the light source and the mask is increased, but since the X-ray intensity is inversely proportional to the square of Sa, there is a drawback that the time required for exposure becomes long. Furthermore, there is also a drawback that the exposed area is limited due to the above-mentioned image deviation. An object of the present invention is to solve these drawbacks by making it possible to simultaneously expose a plurality of wafers using a set of X-ray sources and a mask alignment mechanism, and will be described in detail below.

FIG. 3 shows an embodiment of the present invention, in which 31 is a turntable that rotates around an axis 32, 33 is an X, Y, and θ stage, 34 is a turntable, a mask that can be fixed to 31, and 35 is an X-ray source, and four or more XYθ stages 33 and masks 34 are arranged concentrically on the turntable 31, and the central axis 3 of the turntable 31 is
It faces an X-ray source 35 located on the extension line of 2.

Further, 36 is a mark detection device, and 37 is a positioning control device. A device, which is fixed outside the turntable 31,
This corresponds to one of the multiple sets of X, Y, θ, stage 33 and mask 34. 38 is an X-ray shielding plate.

To operate this, a wafer is set on the X, Y, and one theta stage 33 at position 40, the turntable 31 is rotated by a predetermined angle in the direction of arrow 41, and the mask 34 is marked at position 42. The detection device 36 has X, Y, θ,
The stage 33 is made to correspond to the alignment control device.

At position 42, . 'The mask and wafer are aligned in front, back, left and right positions and angles, and at the same time, the wafer is set on the next X, Y, θ stage 33 at position 40.

The X, Y, θ stage 33 at position 42, which has been aligned, is locked, and the rotation of the turntable 31 moves the stage 33 to position 42.
It comes to position 3 and is exposed to X-rays. The next mask 34 at position 42 and the wafer are aligned, and a new wafer is set on the next X, Y, θ stage 33 at position 40.

Note that due to the X-ray shielding plate 38,
The line is not illuminated. Thereafter, the turntable rotates every time l/n of the exposure time (n=4 in the case of six divisions as shown in FIG. 3B) passes, and the above operation is repeated. The wafer is then exposed at positions 43, 44, 45, and 46, respectively. As explained above, in the first embodiment of the present invention, a plurality of wafers can be exposed simultaneously, so that the processing capacity is several times greater than that of the conventional apparatus. Further, since the plurality of wafers are placed perpendicular to the line connecting the center of the wafers to the light source, there is an advantage that distortion can be minimized. The present invention can expose multiple wafers at the same time using one set of X-ray light source, mark detection device, and alignment control device, so it has high precision and processing ability, and can be used for manufacturing semiconductor devices with fine patterns. be able to.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a conventional X-ray exposure apparatus, Figure 2 is a diagram showing the state of distortion during X-ray exposure by the apparatus of Figure 1, and Figure 3 is an illustration of a conventional X-ray exposure apparatus.
The figures are explanatory diagrams of one embodiment of the present invention, with FIG. 3a being a side view and FIG. 3b being an explanatory diagram of exposure. 31... Turntable, 32... Rotating axis, 33... X, Y, θ stage, 34...
...Mask, 35...X-ray light source, 36...
... Mark detection device, 37 ... Positioning control device, 41 ... Turntable rotation direction,
40-46...Position on the turntable.

Claims (1)

[Claims] 1. An X-ray light source, a turntable having a rotation axis and whose extension line passes through the X-ray light source, and four or more XYθ stages that can slightly move the position and angle, with a perpendicular line passing through the center of each stage. are placed on the turntable concentrically at equal intervals so as to pass through the X-ray light source, and the wafer is fixed to the turntable with a slight gap between the wafer and the wafer fixed to the XYθ stage. X, characterized in that it is equipped with a mask, and a set of mark detection device and alignment control device that can correspond to all the mask/wafer/XYθ stage sets on the turntable by rotating the turntable. Line exposure equipment.