JPH04240718A - Electron beam lithography by variably forming type charged electron particle - Google Patents

Abstract

PURPOSE:To simply correct the rotation setting difference between a first forming aperture and a second forming aperture and perform beam lithography. CONSTITUTION:A forming signal and a deflecting signal are sent to an electromagnetic deflecting device 11 and an aligning deflecting device 9, respectively, from a CPU 14 and a mark is scanned by the formed image of a first overlapping area. Based on the intensity change of a reflecting electron generated from the mark by the scanning, the position of the sides of the overlapped area are measured. Then, different forming signals and deflecting signals are set to the electromagnetic deflecting device 11 and the aligning deflecting device 9 from the CPU 14 and the mark M is scanned by the formed image of a second overlapped area. Based on the intensity change of an reflecting electron generated from the mark by the scanning, the position of the sides of the overlapped area are measured. The rotation is set for a second forming aperture 6 by a rotation correcting mechanism 13 so as to permit the firstly measured sides and the secondly measured sides to be accorded. Then, different forming signals and deflecting signals are sent to the electromagnetic deflecting device 11 and the aligning deflecting device 9, respectively, the mark is scanned by the formed image of a third overlapped area, and the rotation is set for a first forming aperture 3 by a rotation correcting mechanism 12 so as to fix the wave height of the intensity change of a reflecting electron generated from the mark by the scanning.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable-shaped charged particle beam drawing method that accurately performs charged particle beam drawing on a material.

0002

2. Description of the Related Art FIG. 6 shows a schematic diagram of a variable shaping type electron beam lithography apparatus. In the figure, 1 is an electron gun, 2 is an irradiation lens, 3 is a first shaping aperture, 4 is a shaping lens, 5 is a shaping deflector, 6 is a second shaping aperture, 7 is a reduction lens, 8 is an objective lens, and 9 is a positioning A deflector, 10 is a material to be drawn, 11 is an electromagnetic deflector, and 12 and 13 are rotation correction mechanisms.

In such an apparatus, an electron beam emitted from an electron gun 1 is irradiated onto a first shaping aperture 3 by an irradiation lens 2. The aperture image of the first shaping aperture 3 is formed onto the second shaping aperture 6 by the shaping lens 4, but the position of the image formation can be changed by the shaping deflector 5. The image formed by the second forming aperture 6 is transmitted to the drawing material 1 via a reduction lens 7 and an objective lens 8.
0 is irradiated. The irradiation position on the drawing material 10 can be changed by a positioning deflector 9.

By the way, the openings of the first and second shaping apertures 3 and 6 are rectangular or square, and the openings of the first and second shaping apertures 3 and 6 are rectangular or square.
As shown in FIG. 7, the size of the aperture image of the shaping aperture can be determined by varying the area P where the aperture image m of the first shaping aperture 3 overlaps the opening n of the second shaping aperture 6 (shaded area in the figure). Can be adjusted. In other words, the electron beams in this overlapping region P irradiate the material 10 to be drawn, so when it is desired to widen the width of the beam irradiated onto the material 10 to be drawn, the shaping deflector 5 is operated. When it is desired to increase the overlapping area P shown in 7 and narrow the beam width, the shaping deflector 5 is operated to reduce the overlapping area P. In this way, a rectangular or square image formed by the variably shaped electron beam is irradiated onto the drawing material 10, and these rectangular or square images are connected by the positioning deflector 9 to create a desired pattern. There is.

By the way, if there is a rotational setting error in the forming apertures 3 and 6, the edges of the drawn pattern will not be smooth. For example, when drawing a pattern by connecting three rectangular electron beam shots as shown in Fig. 8, if there is no rotational setting error in the forming apertures 3 and 6, a pattern with smooth edges as shown in Fig. 8 (a) can be obtained. . However, if there is a rotation setting error in the molding apertures 3 and 6, the edges will become a jagged pattern as shown in FIG. 8(b).

The present inventor has previously developed a method for correcting such rotational setting errors of the molding apertures 3 and 6. The electromagnetic deflector 11 was provided by this development, and is an electromagnetic deflector for adjusting the molding aperture rotation setting.

By the way, if each of the X-direction and Y-direction deflectors forming the electromagnetic deflector 11 is tilted with respect to the ideal direction (reference coordinate axis direction), the beam cannot be moved in the ideal direction. Deflection correction must be performed. This deflection correction is performed by moving the electromagnetic deflector 11 in the X direction and in the Y direction in a state where the aperture image m of the first shaping aperture 3 is not obstructed by the second shaping aperture 6 and is completely accommodated in the opening n of the second shaping aperture 6. The drawing material 10 is driven in the direction of
This is done by determining the amount of correction of the drive signal applied to the electromagnetic deflector 11 from the change in the edge position of the upper image, and correcting the drive signal of the electromagnetic deflector 11 using this amount of correction (details are given in the special section). (See Application No. 62-278829).

When the deflection correction is completed, the rectangular image m of the first shaping aperture 3 is moved by the electromagnetic deflector 11 with the aperture image m of the first shaping aperture 3 projected so as to overlap with the second shaping aperture 6. , the rotation correction mechanism 12 based on a change in the edge position of the image on the drawing material 10.
, 13 to correct rotational setting errors of the first shaping aperture 3 and the second shaping aperture 6.

[0009]

[Problems to be Solved by the Invention] However, such a deflection correction operation of the electromagnetic deflector 11 is very troublesome.

The present invention provides a variably shaped charged particle beam that does not require such deflection correction of an electromagnetic deflector, but simply corrects rotation setting errors of a shaping aperture to perform highly accurate charged particle beam drawing. Its purpose is to provide a drawing method.

[0011]

[Means for solving the problem] To that end, the present invention
The beam emitted from the charged particle beam source and passed through the first shaping aperture is projected so as to overlap with the second shaping aperture, and the overlapping shaping is performed by an electromagnetic deflector disposed between the first shaping aperture and the second shaping aperture. The image is moved, and the rotation setting error of the second shaping aperture is corrected based on the change in the edge position of the image on the material, and then the beam passing through the first shaping aperture overlaps with the second shaping aperture to form a beam with a band-shaped cross section. The beam is projected so as to be shaped, and after correcting the rotational setting error of the first shaping aperture so that the lateral intensity distribution of the shaped beam cross section is uniform, beam drawing is performed.

0012

Embodiment FIG. 1 is a schematic diagram of a variable shaping type electron beam lithography apparatus using the method of the present invention. In the figure, the same components as in FIG. 6 are denoted by the same numbers. In the figure, 14 is a CPU, 15, 17, 19 are DA converters, 1
6, 18, and 20 are amplifiers, and 21 is a backscattered electron detector. The CPU 14 not only outputs drawing pattern data but also performs accurate beam drawing. The DA converter 15 is for converting pattern data output from the CPU 14 into an analog signal, and the amplifier 16 is for converting the pattern data output from the CPU 14 into an analog signal.
5 as an input to drive the positioning deflector 9. The DA converter 17 receives a deflection signal for adjusting the shaped beam size from the CPU 14 and converts it into an analog signal.
This is for receiving the output of the A converter 17 and driving the electromagnetic deflector 11. The DA converter 19 receives a deflection signal for deflecting the first shaped aperture image m output from the CPU 14 and converts it into an analog signal.The amplifier 20 receives the output of the DA converter 19 and converts it into an analog signal. , for driving the shaping deflector 5.

Now, prior to pattern drawing, aperture rotation setting error correction is performed as follows. First, a shaping signal (X1, Y1) is sent from the CPU 14 to the electromagnetic deflector 11 via the DA converter 17 and amplifier 18. By supplying the shaping signal, the first shaping aperture image m is located at the first position indicated by the solid line, as shown in FIG. By the way, a cross-shaped mark M is attached near the drawing material 10, as shown in FIG. A cross-shaped pattern of Au is formed on the top. Next, a deflection signal is sent from the CPU 14 to the positioning deflector 9 via the DA converter 15 and the amplifier 16, and the first
The formed image of the overlapping region P is scanned. Then, the position of the a-2 side is measured based on the change in the intensity of reflected electrons generated from the mark by the scanning. Next, the electromagnetic deflector 1 is transmitted from the CPU 14 to the DA converter 17 and the amplifier 18.
Send shaping signals (X2, Y1) to 1. At this time, as described above, if each of the X-direction and Y-direction deflectors forming the electromagnetic deflector 11 is tilted with respect to the ideal direction, for example, as shown in FIG.
As shown in , the first shaping aperture image m is located at the second position indicated by the broken line. Next, a deflection signal is sent from the CPU 14 to the positioning deflector 9 via the DA converter 15 and amplifier 16, and the mark M is scanned with the formed image of the second overlapping region P'. Then, in the same manner as described above, the position of the b-2 side is measured based on the change in the intensity of reflected electrons generated from the mark by the scanning. Then, the rotation of the second shaping aperture 6 is set by the rotation correction mechanism 13 so that the positions of the a-2 side and the b-2 side coincide. By the above operations,
The rotational setting error of the second shaping aperture 6 is corrected.

Next, from the CPU 14 to the DA converter 17
, a shaping signal (
X3, Y3). By supplying the shaping signal, the first shaping aperture image m is located at the position indicated by the solid line, as shown in FIG. Next, a deflection signal is sent from the CPU 14 to the positioning deflector 9 via the DA converter 15 and amplifier 16, and the mark M is scanned with the formed image of the overlapping region P0. Through this scanning, changes in the intensity of reflected electrons generated from the mark (FIG. 5 shows the waveform of the reflected electron signal emitted from the mark) are detected. Then, the rotation of the first shaping aperture 3 is set by the rotation correction mechanism 12 so that the peak value K of the reflected electron signal waveform is constant. As described above, the rotation setting error of the first shaping aperture 3 is corrected.

[0015] Furthermore, an elongated molded image of the overlapping region P0' as shown by the broken line in FIG. The rotation of the first shaping aperture 3 may be set so that the peak value of the reflected electron signal waveform is constant.

[0016]

Effects of the Invention According to the present invention, the beam emitted from the charged particle beam source and passed through the first shaping aperture is projected so as to overlap with the second shaping aperture, and the beam is projected between the first shaping aperture and the second shaping aperture. moving the overlapping formed images by a disposed electromagnetic deflector;
The rotation setting error of the second shaping aperture is corrected based on the change in the edge position of the image on the material, and then the beam passing through the first shaping aperture overlaps with the second shaping aperture to form a beam with a band-shaped cross section. After correcting the rotation setting error of the first shaping aperture so that the horizontal intensity distribution of the cross section of the shaped beam is uniform, beam drawing is performed. There is no need to perform deflection correction of the electromagnetic deflector prior to correction of the rotation setting error of the aperture so that an error in the deflection direction of the electromagnetic deflector disposed between the molding aperture and the second molding aperture does not occur;
It is possible to easily correct the rotation setting error between the first molding aperture and the second molding aperture.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a variable shaping type electron beam lithography apparatus shown for explaining the shaping aperture rotation setting error correction method of the present invention.

FIGS. 2, 3, 4, 5 are used to explain the present invention.

FIG. 6 shows a schematic diagram of a variable shaping type electron beam lithography apparatus.

FIGS. 7 and 8 are used to explain variable shaping drawing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Electron gun, 2... Irradiation lens, 3... First shaping aperture, 4... Shaping lens, 5... Shaping deflector, 6... Second shaping aperture, 7... Reduction lens, 8... Objective lens, 9... Positioning deflector , 10... Material to be drawn, 11... Electromagnetic deflector, 12
, 13... Rotation correction mechanism, 14... CPU, 15, 17, 1
9...DA converter, 16, 18, 20... Amplifier, 21... Backscattered electron detector

Claims (1)

[Claims] Claim 1: A beam having a desired cross-sectional shape is obtained by first and second shaping apertures and a shaping deflector placed between these apertures, and this beam is irradiated onto a material to draw a predetermined pattern. In the variably shaped charged particle beam writing method, the beam emitted from the charged particle beam source and passed through the first shaping aperture is projected so as to overlap with the second shaping aperture, and the beam is projected between the first shaping aperture and the second shaping aperture. The overlapping forming images are moved by the arranged electromagnetic deflector, the rotation setting error of the second forming aperture is corrected based on the change in the edge position of the images on the material, and then the beam passing through the first forming aperture is After projecting the beam so that it overlaps with the second shaping aperture to form a beam with a band-shaped cross section, and correcting the rotational setting error of the first shaping aperture so that the lateral intensity distribution of the shaped beam cross section is uniform. , a variably shaped charged particle beam lithography method that performs beam lithography.