JPS6091636A - Electron beam drawing device - Google Patents

Abstract

PURPOSE:To enable not to differ the shape of a pattern edge according to directions by a method wherein, when the substrate to be drawn is being irradiated with electron beams, the irradiation is interrupted in every prescribed unit hour and the drawing pattern is constituted of unit dots. CONSTITUTION:A deflection electrode 116 is synchronized to a synchronous signal, which is sent from a synchronous circuit 123, deflects periodically electron beams and makes the electron beams scan on a substrate 110 to be drawn. A blanking electrode 115 is made an ON-OFF control by a blanking circuit 125 according to the pattern of a pattern memory 126 for drawing. A dot blanking control circuit 128 makes the irradiation of the electron beams interrupt in every constant hour during a time when the electron beams are being irradiated and controls the electrode 115 in such a way that the scanning lines of the electron beams are formed ina dotted pattern. According to this constitution, the rectangular pattern is drawn in such a way as to formed of unit patterns in a dotted condition. Accordingly, it is eliminated that the shape of the patternedge is different in the X direction and the Y direction.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electron beam lithography system, and in particular to an electron beam lithography system for integrated circuits.
The present invention relates to an electron beam lithography device for lithography.

[Technical background of the invention and its problems] In conventional electron beam lithography equipment, the electron beam is deflected by a predetermined width, and the electron beam is turned on and off according to the /e-turn to be lithographically applied to semiconductor wafers, photomasks, etc. Draw a pattern on the board to be drawn.

For example, when drawing two rectangular patterns 1 and 2 as shown in FIG. Turn off. Similarly, the beam is turned on at the beam deflection position 21 and turned off at the beam deflection position. Next, move the stage on which the drawing board is mounted by 1 in the Y direction.
Move the line width and draw the next line. Turn on the beam at beam deflection position #13, turn off the beam at beam deflection position #14, turn on the beam at beam deflection position n,
The beam is turned off at beam deflection position u. Similarly, all the lines are drawn in step 2, and the drawing of the rectangular turn 1°2 is completed. However, in the case of such a drawing method, there is a problem that the shape of the pattern edge is different between the X direction, which is the deflection direction, and the Y direction, which is the direction perpendicular to the deflection direction. This is because the R-turn edge in the X direction is straight, whereas the pattern edge in the Y direction is uneven.

In addition, the area (frame) of a predetermined width in which the electron beam can be deflected at once is about one angle at most, and as shown in Fig. 2 (1), the frame boundary is located between ξ turns 3
may be drawn. For such pattern 3, the beam is first turned on at a beam deflection position 31, and the beam is deflected while remaining on until the final position 32 where the beam can be deflected. Next, pattern 3 is created by moving the scan in the Y direction.
After drawing the left half of pattern 3, move the board by the frame width in the X direction and draw the right half of pattern 3 (normally, the left half is drawn from the top and the right half is drawn from the bottom).

When drawing one pattern 3 by dividing it into two parts in this way, there is a problem in that the degree of irradiation of the electron beam at the frame boundary is different, resulting in the formation of a depression as shown in FIG. 3 in the drawn pattern. In order to eliminate this concave effect, it has been considered to overlap the beam irradiation by slightly increasing the deflection width of both frames at the frame boundary, but it is said that the accuracy of the formed/e-turn will deviate by the amount of overlap. There's a problem.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and it is possible to draw a desired pattern without any difference in the shape of the pattern edge in the direction of beam deflection and in the direction perpendicular thereto, and without any abnormality in the shape of an e-turn at the frame boundary. The purpose of the present invention is to provide an electron beam lithography device that can perform the following steps.

[Summary of the invention]

In order to achieve this object, the electron beam lithography apparatus according to the present invention irradiates the substrate to be drawn with an electron beam, and while the electron beam is irradiating the substrate, the irradiation is intermittent at predetermined unit time intervals to form a pattern to be drawn on the substrate to be drawn. It is characterized by being composed of predetermined unit dots.

[Embodiments of the invention]

FIG. 4 shows an electron beam lithography apparatus according to an embodiment of the present invention. Substrate 1 to be imaged such as a semiconductor wafer or a photomask
10 is fixed to an XY stage 111. The X-Y stage 111 can be moved in the X direction and the Y direction by an X-Y drive motor 112. The current position of the X-Y stage 111 is measured by a laser interferometer 120 and a position measurement circuit 121, and based on the difference between the measured current position and the target position, the X-Y position control circuit 122 determines the
Controls the Y drive motor 112. x-y stage 111
An electron gun 113 is provided above so as to face the surface of the substrate 1100 to be imaged. Electron gun 113 and x-y
Between the stay V 111, there is a condenser lens 114 that focuses the electrons emitted from the electron gun 113, a blanking electrode 115 that controls on/off the irradiation of the particle beam onto the substrate 110 to be drawn, and a deflector that scans the electron beam. Electrode 1
16 are provided. The deflection electrode 116 is connected to the synchronous circuit 1
The electron beam is periodically deflected in synchronization with a synchronization signal from 23 to scan the substrate 110 to be imaged. The blanking electrode 115 is controlled on/off by a blanking circuit 125 according to a pattern in a pattern memory 126 for drawing. This embodiment is characterized in that it has a dot blanking control circuit 128 connected to a drawing control circuit 127. This dot blanking control circuit 128 is
During irradiation with the electron beam, the irradiation is interrupted at regular intervals to control the blanking electrode 115 so that the scanning line of the electron beam becomes dot-shaped. The pattern in the drawing pattern memory 126 is the pattern data 129
is created by the computer system 130 based on. The computer system 130 also controls other circuits based on the Noreen data 129.

Next, the drawing operation by the electron beam drawing apparatus according to this embodiment will be explained. Same rectangular R turns 1 and 2 as in Figure 1 (1)
When drawing, as shown in Figure 5 (1) and (2),
First, the beam is turned on at the beam deflection position 11, but instead of scanning until the beam deflection position 12 remains on,
After scanning while remaining on for a predetermined unit time, the beam is turned off for a short time and then turned on again for a predetermined unit time. The dot blanking control circuit 128 performs this operation. This is repeated until the beam deflection position (112) is reached. Then, as shown in Fig. 5 (
As shown in 1), a dot-shaped unit pattern (more precisely, a unit turn having a dot-shaped exposure density distribution) is formed at 11 or 12 beam deflection positions. The beam deflection positions 12 to 21 are scanned in the off state,
After turning on the beam at beam deflection position 2J, the dot blanking control circuit 128 similarly turns on/off the beam.
A dot-shaped unit pattern is formed by off-control. After the beam is turned off at the beam deflection position n and scanning of this line is completed, the target substrate 110 is moved by one line width in the Y direction, or the electron beam is deflected in the Y direction to scan the next line. will be carried out.

When all lines have been scanned, rectangular patterns 1 and 2 are drawn in the form of dot-shaped units/turns, as shown in FIG. 5(1). Therefore, there is no difference in the shape of pattern edges in the X direction and the Y direction.

Next, for the rectangular turn 3 with the same frame boundary as in Fig. 2 (2), when the beam is on, as shown in Fig. 6, Intermittent beam. In this way, the rectangular pattern 3 is drawn so as to be formed by dot-shaped unit patterns. Therefore, the shape of the pattern edge is the same in both the X and Y directions, and the shape of the frame boundary is not particularly different from other parts.

There are various shapes of electron beams, such as circular beams, rectangular beams, and variable shaped beams, and the present invention can be applied to any of them. In addition, the size and shape of a dot-like unit pattern, etc., differ depending on the time the beam is turned on and off, and how long these times are determined depends on the writing conditions. - Determined by the type of resist, substrate to be drawn, etc.

〔Effect of the invention〕

As described above, according to the present invention, since the drawing pattern is drawn in dot-like unit patterns, the shape of the noso-turn edge does not vary depending on the direction, and a predetermined pattern can be drawn without causing shape abnormalities at frame boundaries. be able to.

[Brief explanation of drawings]

Figures 1 (1) and (2) and Figures 2 (1) and (2) are diagrams showing the writing operation by a conventional electron beam writing apparatus, respectively.
FIG. 3 is a diagram that does not show a specific example of a pattern drawn by the same device, FIG. 4 is a block diagram of an electron beam drawing device according to an embodiment of the present invention, and FIGS. Figures (1), (2
) are diagrams each showing a drawing operation by the same device. 110... Substrate to be drawn, 111... X-Y stage, 112... X-Y drive motor, 113... Electron gun, 114... Condenser lens, 115... Blanking electrode, 116 ... Deflection electrode, 120 ... Laser interferometer, 121 ... Position measurement circuit,
122... X-Y position control circuit, 123... Synchronization circuit, 124... Deflection circuit, 125... Blanking circuit, 126... Pattern memory for drawing, 127...
・Drawing II! l1itill# circuit, 129... turn data, 130... computer system. Applicant's agent Kiyoshi Inomata Figure 1 Figure 4 Figure 5

Claims (1)

[Scope of Claims] Deflection means for deflecting an electron beam to scan the substrate to be drawn in a first direction, and a scanning line of the electron beam by the deflection means in a second direction different from the first direction. an electron beam lithography device that draws a desired /e turn on the substrate with an electron beam; In the above, the control means is configured to 'intermit irradiation at predetermined unit time intervals during irradiation of the electron beam onto the target substrate, and configure a pattern to be drawn on the target substrate to be composed of predetermined unit dots. Characteristic electron beam, Trl, Toto 1 (.