JPH0559577B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a charged particle beam writing apparatus suitable for electron beam exposure, ion beam implantation, and the like.

(Prior Art) For example, electron beam exposure methods are broadly classified into single-stroke writing methods and batch exposure methods. Of these two methods, the latter is superior in drawing speed, but
A mask having an original pattern, ie, a pattern shape to be imaged onto the object to be exposed, is required. This pattern is usually quite complex and presents various problems such as difficulty in mask fabrication, difficulty in replacement, and inability to use surrounding shapes.

(Problems to be Solved by the Invention) The present invention has been made in order to address the above-mentioned problems, and provides a charged particle beam lithography system that takes advantage of the ability to irradiate a wide area at once in the batch exposure method. It is.

[Structure of the Invention] (Means for Solving Problems) Next, the basic concept of the present invention will be explained with reference to FIG. In FIG. 1, an electron beam 11a is extracted from, for example, an electron beam light source, so-called electron gun 11, which serves as a charged particle beam generating means. This beam 11a is controlled on and off by, for example, a blanking electrode (not shown). The electron beam 11a, which is controlled by the blanking electrode and passes through the blanking slit in the latter stage, is passed through the first slit 12a and the second slit 12b to the electron lens 13 to form a pattern of a predetermined figure on the object to be drawn. imaged as.

(Function) According to the present invention, the charged particle beam that has passed through the first slit is irradiated onto the second slit, shaped, and irradiated onto the object to be drawn. At this time, the second slit 12b electrically moves in the X direction and the Y direction. In this embodiment, instead of actually moving the second slit, the beam is deflected to equivalently change the relative relationship between the first and second slits. By moving the second slit 12b relative to the first slit, the figure can be moved, for example, to the second slit.
It can be changed as appropriate as shown in Figures a, b, and c.

(Embodiment of the Invention) Next, an embodiment of the present invention will be described in detail with reference to FIG.

In Fig. 3, 31 is an electron gun, and this electron gun 31
An electron beam 31a is extracted from. This beam 31a is focused approximately at the center of the blanking electrodes 34, 34' by the first electron lens 33, and
A so-called crossover image of the electron gun 31 is formed. 35 is a blanking slit, and the voltage of the blanking voltage generating circuit 36 connected to the blanking electrodes 34, 34' is 0 [V].
The beam 31a is allowed to pass when the voltage is 40 [V], and the beam 31a is cut off when the voltage is 40 [V]. The beam 31b that has passed through the blanking slit 35 is a diverging beam, but the second lens 37, which is a condenser lens, converts the beam 31b into a parallel beam as shown in the figure. The slit 38 is irradiated with light. Due to the action of this lens 37, the crossover image of the electron gun 31 is not focused on the first slit 38 position, and the electron beam is uniformly irradiated over the entire area of the predetermined hole of the first slit 38. . That is, since the crossover image of the electron gun 31 is not focused at the first slit 38 position, the spot beam that would be generated when the electron gun light source is imaged at the slit 38 position is reduced in the plane of the first slit 38. Since there is no locally high energy beam density distribution, a uniform and uniform beam can be obtained. Furthermore, since the scattered beam is changed into a parallel beam at the first slit 38 position, a higher beam current density can be obtained than if the diverging beam is used as it is. This first slit 38 is located at 12 in FIG.
This corresponds in principle to a.

Hereinafter, the light source will be explained assuming that it is the opening of the first slit 38. In other words, the actual light source is the electron gun 3.
However, for the object to be drawn, the first slit 38 serves as a uniform light source (virtual light source) with a relatively high beam current density as described above. Here, it should be noted that the way of expressing the luminous flux when the first slit 38 is used as a light source below the first slit 38 opens at the point where the virtual light source is focused, and is expressed as a normal light source flux. The point is that it is the opposite. This is to simplify the drawing. The first slit 38 is used as a virtual light source, and the square image, which is regarded as a special rectangular shape, is formed by the third lens 3.
a second slit 4 defined by 9 in a rectangular shape;
The image of the first slit is configured to be focused on zero. In this case, the crossover image of the electron gun 31 is not focused on the second slit 40, but is focused between the third lens 39 and the second slit 40 according to the convex lens imaging formula. Therefore, a uniform beam can be obtained at the second slit 40 position as well as at the first slit 38.

Here, the beam 32a is connected to the deflection electrodes 41, 41'.
When the voltage applied to 44 and 44' is 0 [V], all of the light passes through, creating a square shape in the second slit 40. and second slit 4
The square opening, which is here considered to be a special rectangular shape, provided at 0 has a side of 2.56 [mm].
The beam 32a also has deflection electrodes 41, 41' and 44,
0.1 [V] in each of the x and y directions by 44'
It is designed to deflect by 0.01 [mm] per point.
Therefore, when a voltage of 25.6 V is applied between the deflection electrodes 41 and 41', the beam 32a is completely cut off.

For example, if you want to finally obtain a rectangular figure of 5 [μm] x 100 [μm], use the minicomputer 5, which is an electronic computer.
5, "5" is written in the first register 42 as the width information in the x direction, and "100" is written in the second register 45 as the width information in the y direction.
Then, the output of the D-A converter 43 is 25.1
[V], the output of the D-A converter 46 is 15.6 [V]
voltage is beginning to appear. For this reason,
Only the beam 32b having a width of 50 [μm] in the x direction and 1 [mm] in the y direction finally passes through the second slit 40.
will pass through. In this state, as is clear from FIG. 3, the outline of the cross section of the electron beam that has passed through the hole of the first slit 38 at the position of the second slit 40 intersects the outline of the second slit hole at two points. It turns out. The beam 32b passing through this second slit 40 is transmitted through the objective lens 47.
The image is reduced to 10:1, and the virtual light source, that is, the first slit, is focused on the flat object to be exposed 48 as the object to be drawn. and 5
A rectangular figure 60 with a desired size of [μm]×100 [μm] is obtained. Here, the beam 32b is further deflected in the x direction by deflection electrodes 49, 49' while maintaining its rectangular shape. The amount of deflection is determined by the content given to the third register 50 by the minicomputer 55, and a desired deflection voltage is taken out to the third converter 51. However, it should be noted that the center position of the rectangle generated in the second slit 40 differs depending on the size of the rectangle, so the value stored in the third register 50 will not be stored in the register 42. Corrections must be made in relation to the values entered. Of course, an uncorrected value may be used here, and correction may be made using an electrical circuit by appropriately adding the output voltage of the first converter 43 to the output voltage of the third DA converter 51. Similarly, the beam is deflected in the y direction by the deflection electrodes 52 and 52' while maintaining its rectangular shape. As for this amount of deflection, a desired deflection voltage is taken out to the fourth DA converter 54 according to the contents given to the fourth register 53 by the minicomputer 55. By the way, in this embodiment, after drawing the figure inside the 256 step angle, the object to be exposed 48 is moved to the next step under the control of the minicomputer 55, and the next frame is drawn. Means such as a circuit and a motor for this purpose are omitted in the figure. Further, in order to suppress the heat generation of the first slit 38 and the second slit 40 as much as possible, it is possible to additionally cool the first slit 38 and the second slit 40 with water, or to place a slightly larger slit immediately before each slit. In this way, an original pattern mask can be electrically created and a predetermined electron beam exposure can be performed while taking advantage of the feature of the batch exposure method that allows a wide area to be exposed at once.

In the above embodiment, the case where the first slit 38 and the second slit 40 have one opening has been described, but even if a plurality of openings are provided, the same implementation as in the above embodiment is possible. Furthermore, in the above embodiment, a square shape is obtained when the voltage applied to the deflection electrodes 41, 41' and 44, 44' is 0 [V], but when the voltage is 0 [V], the beam 32a is completely cut off. It is also possible to do so. Furthermore, it is also possible to replace the electron beam with an ion beam, and it is also possible to selectively implant ions only into necessary portions.

[Effects of the Invention] According to the present invention, a beam pattern of an arbitrary shape can be obtained using a uniform beam with a high beam current density as a light source, and the brightness of the formed pattern does not change.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram for explaining the basic concept of the present invention, Figures 2a to 2c are schematic diagrams showing figures drawn in Figure 1, and Figure 3 is a diagram of the book. FIG. 1 is a configuration diagram showing an embodiment according to the invention. In Figure 3, 31 is an electron gun, 31a, 31b, 3
2a, 32b are electron beams, 33, 37, 39,
47 is an electronic lens, 34, 34', 41, 41',
44, 44', 49, 49' and 52, 52' are deflection electrodes, 35 is a blanking slit, 38 is a first slit, 40 is a second slit, 48 is an object to be exposed, 42, 45, 50 , 53 are registers, 43, 46, 51, 54 are D-A converters, and 55 is a minicomputer.

Claims (1)

[Claims] 1. A charged particle beam generating means that generates a charged particle beam, a condenser lens that converts the charged particle beam into a parallel beam, and a first slit that allows the beam to pass through as a beam bundle of a predetermined shape.
A second slit is provided between the first slit and the object to be drawn, and a second slit is provided between the first slit and the second slit to focus the first slit image onto the second slit. a lens that generates a charged particle beam and connects the crossover of the beam from the charged particle beam generating means to a position away from the second slit; The charged particle beam passing through the slit is transferred to the second beam according to predetermined information.
means for deflecting the charged particle beam onto the second slit to form a beam beam having variable dimensions; and an objective lens for forming an image of the charged particle beam having passed through the second slit on the object to be drawn; A charged particle beam drawing device that forms a pattern with a desired shape and size by irradiating a charged particle beam onto an object to be drawn.