JPS603774B2 - Electron beam exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam exposure apparatus that exposes rectangular patterns of various areas at once.

As a related matter, there are many known electron beam exposure apparatuses that focus an electron beam into a narrow one and perform scanning with the electron beam to expose a predetermined pattern.

However, exposure using such devices takes a lot of time. Therefore, in recent years, an apparatus has been developed that can complete a rectangular pattern based on a rectangle in a single exposure.

Also, devices have been considered in which the size of the rectangular pattern can be varied over a considerable range. FIG. 1 is an explanatory diagram showing one example, and FIG. 2 is an explanatory diagram showing another example.

In these figures, 1 is the electron gun, 2 is the first slit,
3 is a second slit, 4 is a deflector, 5 is a first electron lens, 6 is a second electron lens, and 7 is a third electron lens.

In both the conventional examples shown in FIGS. 1 and 2, the electron flow is deflected by a deflector 4 so that an image of the electron flow passing through the first slit 2 is formed on the second slit 3.
The overlapping state of the first slit image and the second slit 3 is changed to control the pattern of the electron flow passing through the second slit 3 (namely, the size of the image).

Although the pattern of the electron flow passing through the second slit 3 is not shown, it is reduced by a separately provided electron lens, and then projected onto an appropriate position on the semiconductor wafer through a positioning deflector. be. In the subordinate example, the image of the first slit 2 is projected onto the second slit 3 in a one-to-one relationship, that is, the image=M=.

In the case of FIG. 1, the image passes through the center of the second lens 6, so there is little aberration, but the number of electron lenses increases,
Furthermore, since a deflector is included in the electron lens, the electron lens must be made large. In the case of Figure 2,
Although the number of electron lenses can be reduced, since the image passes through the peripheral portion of the second lens 6, aberrations become large. Furthermore, a common drawback of these conventional examples is that when a pattern is projected onto a semiconductor wafer, the image formed by the first slit 2 has larger pockets than the image formed by the second slit 3. Therefore, the pattern is no longer symmetrical. That is, in the rectangular pattern P shown in FIG. 5, if the image is formed in the first slit 2 and the image * is formed in the second slit 3, the pocket in the image is large. be. Now, apart from the above, if one deflector is used to swing the electron flow, as shown in the subordinate examples of Figs. 1 and 2,
As seen in FIG. 3, the path of the electron flow that passes through the second slit 3 also changes.

Therefore, as shown in FIG. 4, another deflector 4' is used to deflect the Kame-Zoko flow so that the electron currents can pass through the second slit 3 in a substantially orthogonal state. things are being done. It should be noted that even with the configuration shown in FIG. 4, the disadvantages such as the blurring of the image described with reference to FIGS. 1 and 2 cannot be solved. The present invention provides an electron beam exposure apparatus that can obtain sharp images without major modifications or additions, and will be described in detail below.

The inventor conducted numerous experiments and found that forming a reduced image of the first slit 2 on the second slit 3 is the simplest and most effective way to eliminate the pockmarked image. Ta.

The reduction rate is sufficient for the back of the house. In this way, in order to form a reduced image on the second slit 3, it is necessary that a>b, but considering the deflection of the electron beam explained with reference to FIG. , a>b cannot be easily satisfied.

Therefore, in the present invention, a deflector 4 that changes the size of the image and a deflector 4' that swings back are installed between the first slit 2 and the second lens 6, and the second lens 6 and the second slit 3 are brought close to each other. However, in order to do so, other conditions are required.

FIG. 6 is an explanatory diagram of one embodiment of the present invention, and the same symbols as those used in FIGS. 1 to 4 indicate the same parts.

As is clear from the figure, the return deflector 4' is installed between the first slit 2 and the second lens 6.

Therefore, in the case of a C mechanism where a>b can be determined arbitrarily, an appropriate reduced image as described above can be formed on the second slit 3 by rubbing 3 to 0'. By the way, in the embodiment shown in FIG. 6, the electron flow that has passed through the deflector 4' for deflection passes through the second lens 6, so that the electron flow that has passed through this second lens 6 is approximately perpendicular to the second slit 3. need to become
For this purpose, as shown in FIG. must be placed in

Therefore, b; (focal length of the second lens 6). These are new conditions necessary to make a>b.
As can be seen from the above explanation, according to the present invention, a sharp pattern can be formed by making some changes to the arrangement of the members used in the follower device. The performance of the electron beam exposure apparatus can be further improved without causing a large economic burden.

[Brief explanation of drawings]

1 to 4 are explanatory diagrams of a conventional example, FIG. 5 is an explanatory diagram of a pattern, and FIGS. 6 and 7 are explanatory diagrams of an embodiment of the present invention. In the figure, 1 is an electron gun, 2 and 3 are slits, and 4 and 4'
is a deflector, and 5, 6, and 7 are lenses. O Figure O 2 Figure O S Figure O 4 Figure O 5 Figure O 6 Figure Soup 7 Figure

Claims (1)

[Claims] 1 A first slit placed on one side of the electron lens, a second slit placed on the other side, a deflector for changing the size of an image placed between the first slit and the lens, and a deflector for deflecting the electron flow, the electron flow deflected by the deflector passing through a focal point on one side of the lens, and a second slit located at a position where the electron flow deflected by the deflector passes through a focal point on the other side of the lens. forming an image on the lens, where a>b, where a is the distance between the first slit and the lens, and b is the distance between the lens and the second slit. An electron beam exposure apparatus characterized by: