JPH0727859B2 - Charged particle beam writing system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable shaped beam type charged particle beam drawing apparatus suitable for electron beam exposure, ion beam implantation and the like.

[0002]

2. Description of the Related Art For example, an electron beam exposure method is roughly classified into a one-stroke writing method and a collective exposure method. The latter of these two methods is superior in drawing speed, but requires a mask having an original drawing pattern, that is, a pattern shape to be imaged on an object to be exposed. This pattern is usually quite complex, making it difficult to make masks, difficult to replace,
There are various problems such as the inability to use a figure surrounded by the surroundings.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and provides a charged particle beam drawing apparatus which makes use of the feature of being able to irradiate a large area at a time in a batch exposure system. is there.

[0004]

Next, the basic concept of the present invention will be described with reference to FIG. In FIG. 1, an electron beam (11a) is extracted from, for example, an electron beam light source, that is, an electron gun (11) as a charged particle beam generating means. This beam (11a) is on / off controlled by a blanking electrode (not shown), for example. The electron beam bundle (11a), which is controlled by the blanking electrode and has passed through the blanking slit (not shown) in the subsequent stage, has the first
An image is formed as a pattern of a predetermined figure on the object to be drawn by the electron lens (13) through the slit (12a) and the second slit (12b).

[0005]

According to the present invention, the charged particle beam bundle passing through the first slit is irradiated onto the second slit to be shaped,
The object to be drawn is irradiated. At this time, the second slit (12b) may be electrically moved in the X direction and the Y direction, but in the present embodiment, instead of actually moving the second slit, the beam is deflected to be equivalent. To change the relative relationship between the first and second slits. This second slit (12
The pattern of the figure on the object to be drawn is moved by the relative movement to the first slit in FIG. 2B, for example, as shown in FIGS.
It can be changed appropriately as shown in (c).

[0006]

Next, one embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 3, (31) is an electron gun, and an electron beam (31a) is extracted from this electron gun (31). This beam (31a) is emitted by the first electron lens (33).
As a result, a so-called crossover image of the electron gun (31) is formed with the focal point substantially at the center of the blanking electrodes (34) and (34 '). (35) is a blanking slit, which includes blanking electrodes (34) and (34 ').
When the voltage of the blanking voltage generation circuit (36) connected to is 0 [V], the beam (31a) is passed and
The beam (31a) is cut off at the time of [V]. Since a relatively high voltage of, for example, 40 [V] is used in this way, it is possible to largely deflect the beam and effectively pass the beam even through the blanking slit (35) having an opening having a relatively large area. Or it can be blocked. Conversely, the blanking electrodes (34), (3
When a low voltage is applied to 4 '), a large deflection cannot be made, so the opening of the blanking slit (35) needs to be made smaller. In this case, since the beam (31a) is narrowed down by the blanking slit (35), only a low current density can be obtained by the first slit (38), but as in this embodiment, the blanking electrode (3) is used.
Since the blanking slit (35) does not have to be made small as long as a configuration in which a relatively high voltage is applied to 4) and (34 '), a large beam current density can be obtained with the first slit (38). it can.

The beam (31b) which has passed through the blanking slit (35) is a diverging beam, but is converted into a parallel beam as shown in the figure by a second lens (37) which is a condenser lens, and has a rectangular shape. The first slit (38) defined in 1. This lens (3
By the action of 7), the crossover image of the electron gun (31) is not formed at the position of the first slit (38), and the electron beam is spread over the entire area of the predetermined slit of the first slit (38). Irradiated uniformly. That is, the crossover image of the electron gun (31) is the first slit (38).
Since they are not connected at a position, a locally high energy beam density distribution, such as a spot beam generated when the electron gun light source is imaged at the slit (38) position, does not occur in the plane of the first slit (38). Therefore, a uniform and uniform beam can be obtained. Moreover, since the divergent beam is changed into a parallel beam at the position of the first slit (38), a higher beam current density can be obtained than when the divergent beam is used as it is. This first slit (38) is indicated by (12a) in FIG.
In principle, it corresponds to.

Hereinafter, the light source will be described by considering it as the opening of the first slit (38). That is, although the actual light source is the electron gun (31), for the object to be drawn, the first slit (38) is a uniform light source (virtual light source) with a relatively high beam current density as described above. Become. Here, it should be noted that the way of expressing the luminous flux when the first slit (38) below the first slit (38) is used as the light source is opened at the point connecting the focal point of the virtual light source, The point is that the expression and the expression of are reversed. This is to simplify the drawing. The square image, which is regarded as a rectangular special shape here by using the first slit (38) as a virtual light source, is formed on the second slit (40) defined by the third lens (39) in a rectangular shape. It is configured to focus the image of the slit. In this case, the crossover image of the electron gun (31) is not formed at the position of the second slit (40), and the third lens (3
9) and the second slit (40). Therefore, a uniform and uniform beam can be obtained at the position of the second slit (40) as well as the position of the first slit (38).

Here, the beam (32a) is directed to the deflection electrode (4).
When the voltage applied to 1), (41 ') and (44), (44') is 0 [V], all of the light is transmitted to form a square in the second slit (40). And the second
The square opening provided in the slit (40), which is regarded as a rectangular special shape here, has a side of 2.56 [mm]. The beam (32a) is also deflected by the deflection electrode (4
1), (41 ') and (44), (44'), 0.01 [m] per 0.1 [V] in the x and y directions, respectively.
m] designed to deflect. Therefore, when a voltage of 25.6 [V] is applied between the deflection electrodes (41) and (41 '), the beam (32a) is all cut off. That is, the first slit (3) is set to the second slit (40) with a minute voltage step as low as 0.1 [V].
The image position of 8) can be changed with high accuracy, and the size and shape can be changed with high accuracy.

Finally, for example, 5 [μm] × 100 [μ
When it is desired to obtain a rectangular figure of [m], a minicomputer (55), which is an electronic computer, writes “5” as width information in the x direction in the first register (42) and y in the second register (45). "100" is written as the width information in the direction. Then, 2 is output to the D-A converter (43).
5.1 [V], the output of the DA converter (46) is 1
A voltage of 5.6 [V] appears. Therefore, 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). In this state, the third
As is clear from the figure, the contour of the cross section of the electron beam passing through the hole of the first slit (38) at the position of the second slit (40) intersects the contour of the second slit hole at two points. Become. The beam (32b) that has passed through the second slit (40) is moved to 1 by the objective lens (47).
It is reduced to 0: 1 and the virtual light source, that is, the first slit is focused on the flat plate-shaped exposed object (48) as the drawing object. And 5 [μm] × 100 [μ
A rectangular figure (60) having a desired size of [m] is obtained. Here, the beam (32b) is further deflected by the deflection electrode (4b).
9) and (49 '), the rectangular shape is preserved and is deflected in the x direction. And the deflection amount is the minicomputer (5
According to the contents given from 5) to the third register (50), a desired deflection voltage is taken out to the third converter (51). However, it should be noted that the center position of the rectangular shape generated in the second slit (40) depends on the size of the rectangular shape. The correction must be made in relation to the value entered in (42). Of course, here, an uncorrected value is used, and the third DA converter (51) is used.
The output voltage of the first converter (43) may be appropriately added to the output voltage of 1 to correct the voltage in an electric circuit. Similarly, the deflection electrodes (52) and (52 ') deflect the light in the y direction while keeping the rectangular shape. This deflection amount is determined by the fourth register (5
A desired deflection voltage is taken out to the fourth DA converter (54) according to the contents given to 3). By the way, in the present embodiment, after the internal figure having 256 step angles is drawn, the exposed object (48) is moved to the next step by the control of the minicomputer (55) to draw the next frame. Circuits for this purpose and means such as a motor 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 water-cool or place a slightly larger slit immediately before each slit. In this way, the original mask is electrically created and predetermined electron beam exposure can be performed while making the best use of the feature of the batch exposure method capable of exposing a large area at a time.

In the above embodiment, the first slit (3
Although the case where the number of openings provided in 8) and the second slit (40) is one has been described, a plurality of openings may be provided in the same manner as in the above embodiment. In the above embodiment, a square is obtained when the voltage applied to the deflection electrodes (41), (41 ') and (44), (44') is 0 [V], but the voltage is 0 [V]. It is also possible that the hour beam (32a) is entirely cut. Further, the electron beam can be replaced with an ion beam, and it is possible to selectively ion-implant only a necessary portion.

[0013]

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

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining a basic concept of the present invention.

FIG. 2 is a schematic diagram showing a figure drawn by FIG.

FIG. 3 is a configuration diagram showing an embodiment according to the present invention.

[Explanation of symbols]

31 ... Electron gun 31a, 31b, 32a, 32b ... Electron beam 33, 37, 39, 47 ... Electron lens 34, 34 ', 41, 41', 44, 44 ', 49, 4
9 ', 52, 52' ... Deflection electrode 35 ... Blanking slit 36 ... Blanking voltage generating circuit 38 ... First slit 40 ... Second slit 48 ... Exposed object 42, 45, 50, 53 ... Register 43 , 46, 51, 54 ... DA converter 55 ... Minicomputer

Claims (1)

[Claims] 1. The size of a beam from a charged particle beam generating means is defined by first and second slits, and a deflection electrode provided between the first and second slits for controlling deflection of the charged particle beam. And a variable shaped beam type drawing apparatus which exposes an object to be drawn as a variable shape, which is provided in the preceding stage of the first slit and is for blanking for controlling ON / OFF of a beam from the charged particle beam generating means. A blanking means including an electrode and a blanking slit , the charged particle beam generating means, and the blanking means.
The blanking electrode position is provided between the king means
First lens connecting the crossover of the charged particle beam with
And between the blanking slit and the first slit
A second lens provided in the blanking electrode, a high voltage is applied to the blanking electrode to deflect the blanking slit with a large swing width, and the deflection electrode is lower than the high voltage. A charged particle beam drawing apparatus characterized in that a size and a shape can be changed with high accuracy by giving a minute voltage step.