JPH03205815A - Variable fairing diaphragm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electron beam lithography system, and more particularly to a variable shaping aperture suitable for increasing the density and speed of lithography of a wiring board used for multilayer wiring.

[Conventional technology]

The variable shape lithography method is widely used for high-speed lithography in electron beam lithography equipment, and has already become an indispensable lithography technology for LSI manufacturing. Under these circumstances, variable shaping drawing technology has been pursued with the aim of finer drawing of arbitrary figures. On the other hand, at the heart of large computers is a module with an LSI chip mounted on a ceramic wiring board. As the patterns of this multilayer wiring board have gradually become finer, there has been a demand for patterning to be performed using an electron beam lithography system instead of the conventional optical method. In this case, compared to conventional LSI drawing, there has been a stronger demand for drawing in an arbitrary direction, although the line width is almost constant. In response to such a request, the method shown in FIG. 4(a). With a conventional variable shaping diaphragm that uses a combination of diaphragms having apertures as shown in (b), when attempting to draw pattern 10 as shown in (C) of the same figure, the number of divisions increases and it takes a long time to draw. There was a problem that it was necessary. In addition, as a prior art related to the present invention, Japanese Unexamined Patent Application Publication No. 1987-
148980, JP-A-1-112729, and the like.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a shaping aperture that can reduce the number of divisions of a unit pattern in drawing an arbitrary figure at high speed.

[Means to solve the problem]

In order to solve the above problem, it is sufficient to provide a basic figure for expressing a line pattern in an arbitrary direction with as few divisions as possible as the aperture pattern of the shaping diaphragm. Such figures are basically polygons. Therefore, if you express this basic figure using two apertures and connect them to express a line pattern in any direction,
The above problem can be solved.

[Effect]

Now, consider the basic figure as a regular octagon as shown in FIG. 2(a). For example, if we consider drawing a line pattern tilted at an arbitrary angle using this basic figure,
It can be drawn by making them continuous as shown in FIG. 2(b). In the case of this basic figure, the linearity at the periphery of the pattern is poor in an inclined pattern other than 45 degrees, but it is smoothed by the proximity effect of the resist and becomes smoother. Further, in the case of a multilayer wiring board, which is the main object of the present invention, some unevenness hardly poses a problem. The shaping aperture to realize this drawing method is shown in Figure 2 a)
This can be easily achieved using something like the one shown in the figure. Here, in order to realize the same pattern using the conventional method, it would be as shown in Figure 4 b) 6 Comparing the two, it can be seen that the method of the present invention clearly requires fewer divisions. . That is, the present invention is more suitable for high-speed drawing than the conventional art.

【Example】

Examples of the present invention will be described below. FIG. 1 is a schematic vertical sectional view of an electron beam lithography apparatus according to an embodiment of the present invention. The electron beam 2 emitted from the electron gun 1 is shaped by a first shaping aperture 11 and then projected onto a second shaping aperture 12 by a projection lens 3. At this time, the shaping deflector 6
The electron beam 2 is deflected by the
It comes out from the shaping aperture 12. This electron beam is transmitted through the reduction lens 4
, projected onto the sample 9 by the objective lens 5. At this time,
It is deflected to a desired position by a deflector 8. Further, the electron beam 2 is turned on and off by the plan force -7. The shaping aperture used in this example is shown in FIG. 2(a). That is, the first shaping aperture 11 is a regular octagon, and the second shaping aperture 12 has a shape similar to that of the first shaping aperture. To be precise, the center of the second aperture is the center of the first aperture.
It is large enough to accommodate a diaphragm, and the shape of the first diaphragm is divided into four parts around the periphery, and each part is moved point-symmetrically. If such a shaping aperture is used, by operating the shaping deflector 6, it becomes possible to connect in any direction with a relatively small number of divisions, as shown in FIG. 2b). The embodiment shown in Fig. 2 a) is just one example, and in order to carry out the present invention without impairing the essence of the present invention, the first diaphragm should be configured with a regular 4n (=1.2,...) square shape. Just leave it there. In particular, n= can be considered as a circle and is shown in Figure 3. The shaped electron beam formed by such an aperture can be connected in any direction as shown in the figure. Note that the electron optical system shown in FIG. 1 shows a basic configuration that can realize a variable shaping electron beam, and it goes without saying that the present invention can be practiced without being limited to this configuration.

【Effect of the invention】

As described above, according to the present invention, it is possible to draw a pattern by reducing the number of divisions, which has the effect of shortening the drawing time. This is particularly effective for drawing patterns such as multilayer wiring boards in which the line width of the wiring pattern is approximately constant but in any direction.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the basic configuration of an electron optical system of an electron beam lithography apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view of a shaping aperture according to an embodiment of the present invention and a diagram using the same. An explanatory diagram of an electron beam lithography method, FIG. 3 is a plan view of a shaping aperture according to another embodiment of the present invention, and FIG. 4 is a plan view of a conventional shaping aperture and an explanatory diagram of electron beam lithography using the same. . Explanation of symbols 1...electron gun, 2...electron beam, 3...projection lens, 4...reducing lens, 5...objective lens, 6...
Shaping deflector, 7... Plunker, 8... Deflector, 9
···sample. 10... Desired drawing pattern, 11...
・First shaping aperture, 12-1 Fig. 2 (Ku) (?)

Claims (1)

[Claims] 1. In an electron beam lithography device that projects a first shaping diaphragm onto a second shaping diaphragm to obtain a desired shaped electron beam for drawing, the first shaping diaphragm has a positive 4n (=1, 2,...) composed of squares,
The center of the second shaping diaphragm has a sufficient size to accommodate the projection pattern of the first shaping diaphragm, and the periphery has a shape in which the shape of the first shaping diaphragm is divided into four parts and each part is moved point-symmetrically. A variable shaping diaphragm characterized by: 2. The variable shaping diaphragm according to claim 1, wherein n is 2, that is, the first shaping diaphragm is a regular octagon. 3. The variable shaping diaphragm according to claim 1, wherein n is infinity, that is, the first shaping diaphragm is circular. 4. An electron beam lithography apparatus characterized by using the variable shaping aperture according to any one of claims 1 to 3.