JPS59126629A - Method and device for processing by charged particle beam - Google Patents

Abstract

PURPOSE:To facilitate the formation of patterns in a highly accurate manner by a method wherein charged particle beam is spotted in a slender form utilizing the electrooptical characteristics of a quadrupole lens and an axially symmetric lens. CONSTITUTION:A charged particle beam processing device main body 1 has a radiation cylinder 2 with which a charged particle beam is made to irradiate on the material 5 to be processed, and a processing chamber 3 wherein the material 5 to be processed will be provided. The radiation cylinder 2 has a particle beam source 10, a focusing lens 11, a scanning device 14, a magnetic field type quadrupole lens 12 and an axially symmetric lens 13. When the charged particle beam 4 is focused using the focusing lens 4 only, its spot is formed into a circle, but when the quadrupole lens 12 is used, the spot is formed into a longitudinally slender shape or a laterally slender shape or a circular shape according to the position of the cross section. Besides, when the axially symmetric lens 13 is used, the focusing position of the spot can be adjusted.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is applicable to electron beam exposure equipment, micro ion beam equipment, etc., which perform processing such as exposure, etching, and ion implantation on a processed object using a charged particle beam. The present invention relates to a processing method and apparatus.

Conventional technology Processing equipment using charged particle beams, such as exposure equipment, processes the workpiece by irradiating the workpiece with a charged particle beam such as an electron beam or ion beam to draw a predetermined pattern on the workpiece. Generally, a charged particle beam is formed into a minute circular spot on a workpiece using a focusing lens, and in this state, the charged particle beam is scanned to draw a predetermined pattern on the workpiece.

However, since such a device uses a minute circular charged particle beam, the charged particle beam must be scanned two-dimensionally. In this case, the number of repetitions of charged particle beam irradiation and non-irradiation, scanning, retrace scanning, etc. becomes large.
A program for drawing a pattern has the disadvantage that it becomes complicated and takes a long time to draw.

In order to eliminate the above-mentioned drawbacks, an aperture plate is installed in the irradiation cylinder that generates and irradiates the charged particle beam, making the charged particle beam a relatively large rectangle and drawing a predetermined pattern with one irradiation. was proposed. However, since this device has an aperture plate inside the irradiation station, the irradiation system is complicated and expensive, and although it can draw patterns in two orthogonal directions (vertical and horizontal), it cannot draw diagonal patterns. I can't.

In addition, since the size of the charged particle beam is relatively large, if the charged particle beam is continuously generated and scanned, a difference will occur between the irradiation at the periphery and the center of the drawn pattern, which can be prevented. To do this, in general, a charged particle beam is generated intermittently in synchronization with the scanning, and it is necessary to avoid overlapping the irradiation points of the charged particle beam on the object to be processed.In this way, multiple points are irradiated. Because it has to be done, scanning the charged particle beam and controlling it when it is generated becomes compound interest.

OBJECTS OF THE INVENTION An object of the present invention is to provide a processing method and apparatus using a charged particle beam that can draw patterns at high speed, with high precision, and with high stability without complicated control.

According to the present invention, the above object is to actively utilize the electro-optical characteristics of a quadrupole lens and an axially symmetrical lens (dynamic focus lens) to determine the shape of a charged particle beam on a workpiece. This is achieved by forming a long and thin linear spot and adjusting the focal lengths of both lenses to position the focal point in the width direction of the spot on the surface of the object to be processed.

Embodiment In FIG. 1, reference numeral 1 denotes a main body of a charged particle beam processing apparatus, and an irradiation tube 2 that generates a charged particle beam 4 and irradiates it onto an object to be processed 5;
It has a processing section 3 in which a processing object 5 is provided. Irradiation tube 2
In addition to a particle beam source 10 such as an electron gun, a focusing lens 11 such as a magnetic field type electron lens, and a known scanning device 14 for two-dimensionally scanning the charged particle beam 4, a magnetic field type (
An electric field type may be used, but in the following description, a magnetic field type is used. ) is provided with a known quadrupole lens 12 and an axially symmetrical lens 13.

The particle beam 11n10 is connected to a known particle beam source power source 20, the focusing lens 11 is connected to a known manually adjustable lens power source 21,
The quadrupole lens 12 is connected to an axially symmetrical lens 13 at the output terminal of the digital/analog (hereinafter referred to as DA) inverter 22.
is connected to the output terminal of the DA converter 23, and the scanning device 14 is connected to a known scanning power supply 24.
The A converters 22 and 23 and the scanning power supply 24 are connected to a control device M2 such as a computer via an interface 25.
6.

The charged particle beam 4 emitted from the particle beam source 10 is focused by one focusing lens, the spot shape is changed by the quadrupole lens 12 and the axially symmetrical lens 13, and the object to be processed 5 is irradiated with the beam. The object to be processed 5 is scanned at d3.

When the charged particle beam 4 is focused only by the focusing lens 11 in this device at a5, its longitudinal section becomes as shown in FIG.

The shape of the cross section (spot) drilled at c and d is shown in Figure 2 (B).
It is a circle as shown in the figure, and becomes the minimum (positive focus position) at position C. Therefore, when using only the focusing lens 1], the excitation current ■0 at which the charged particle beam 4 becomes the minimum on the object 5 to be processed
The lens power supply 21 may be controlled by the control I device 26 so that the processing is performed.

On the other hand, if a quadrupole lens 12 is used, as shown in FIG.
The spot shape shown in ) is almost circular at position C as shown in Figure 2 (C), but it becomes a long line in the X direction above it and in the Y direction below it, and the spot shape is the smallest in the width direction. Focus positions d in the width direction exist above and below position C. In this case, the distance ΔF1 from the positive focal point C of the focal point position d in the width direction is proportional to the excitation current 11 of the quadrupole lens 12, so if the proportionality constant is K], ΔF I=K
+・11 ・・・・・・・・・(1).

Furthermore, if the axially symmetrical lens 13 is used, the spot shape shown in FIG.
), it is almost circular at position @b, but it becomes a long line above it in the X direction and below it in the Y direction,
Further, focal positions a and C in the width direction, where the width direction is minimum, exist above and below the positions. In this case, the axially symmetrical lens 13
The moving distance ΔF2 of the focal position due to the axis-symmetric lens 13 is
Since it is proportional to the square of the excitation current I2, the proportionality constant is 2
Then, ΔF 2=K 2・(I2) ・・・・・・・・・(
2) becomes.

Both the quadrupole lens 12 and the axially symmetrical lens 13 are used, and the excitation current II is set so that ΔF1 and ΔF2 are equal.
If +2 is set, the charged particle beam 4 focuses on the object 5 in the width direction. Therefore, from equations C11 and 2, 11/(12) = Kl/2...
- (3) can be obtained. Note that FIG. 2(D) is a diagram when ΔF1 and ΔF2 are made equal in this way.

By changing the length of the charged particle beam 4 on the workpiece 5, it is sufficient to change the excitation current 11 for the quadrupole lens 12.
At this time, if the excitation current I2 for the fist-symmetrical lens 13 is adjusted so as to satisfy Expression 3, the object to be processed 5 can always be focused in the width direction. 11 and 12 are outputted from the control device 26 by calculating the three equations in the control device @26.

In this device, in order to draw a rectangular pattern, the excitation currents 11 and 12 for both lenses 12 and 13 are set by the control device 26 so as to satisfy equation 3, and the excitation currents 11 and 12 are set as shown in FIG. First, the spot shape of the charged particle beam 4 on the workpiece 5 is made into a linear shape of a predetermined length, and in this state, the charged particle beam 4 is
The charged particle beam source power supply 2 is controlled by the control device 26 so that it is generated at the position @AI in FIG.
0, the DA converters 22 and 23 and the scanning power supply 24 may be controlled. In this way, a rectangular pattern can be drawn by simply scanning in one direction (once) while generating a charged particle beam. As a result, a predetermined pattern can be drawn at high speed and with high precision using a simple drawing program by the control device 26.

To draw a linear pattern, the controller 26 sets the excitation current [1 and 12] so as to satisfy the equation 3, and as shown in FIG. 3(B), the charged particle beam 4 is The spot shape on the object 5 is made into a line with a predetermined length, and in this state, a charged particle beam is generated at position B1 in FIG.
．． The particle beam source power supply 20 is controlled by the control device 26 to deflect the charged particle beam stepwise by a distance approximately equal to the length of the charged particle beam as shown in B3, and to generate the charged particle beam 4 in synchronization with this deflection.
, the DA converters 22 and 23, and the scanning voltage 124.

In addition, in the above-described embodiment, one additional set of quadrupole lenses is added, and both quadrupole lenses are provided with their respective magnetic poles separated by 45 degrees from each other, and the current ratio applied to both quadrupole lenses is controlled by the control device 26. For example, the charged particle beam is shown in Figure 2 (E).
As shown in the figure, it is possible to form a diagonal linear pattern, thereby making it possible to draw rectangular and linear patterns extending in a diagonal direction.

In addition, in the above explanation, the case where the irradiation and non-irradiation of the particle beam on the object to be processed is controlled by controlling the generation of the particle beam itself, but on the other hand, the so-called blanking position is A pattern can be drawn in the same way by separately providing a particle beam inside the particle beam, keeping the particle beam as it is generated, and controlling the irradiation of the particle beam with a blanking device.

Effects of the Invention As described above, the present invention transforms a charged particle beam into a linear spot using a quadrupole lens and an axially symmetrical lens, and controls the focal length of both lenses to transform the spot in the width direction. Since the focus is placed on the object to be processed, the number of times the complicated charged particle beam irradiation and non-irradiation, scanning, and retrace scanning are repeated is minimized, resulting in high speed, high precision, and high stability. A predetermined pattern can be drawn on.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an electric circuit showing an embodiment of a processing device according to the present invention, Fig. 2 is an explanatory diagram of a spot shape of a charged particle beam, and Fig. 3 is an explanatory diagram of a scanning method of a charged particle beam. be. 1: Charged particle beam processing device main body, 2: Irradiation tube, 3: Processing chamber, 4: Charged particle beam, 5: Processed object, 10: Particle beam source, 1
1: Focusing lens, 12: Quadrupole lens, 13: Axisymmetric lens, 14: Scanning device. Patent applicant Elionix Co., Ltd. Figure 1 Figure 2 (B)

Claims (2)

[Claims] (1) The charged particle beam is shaped into a linear spot using a quadrupole lens and an axially symmetrical lens, and the focal lengths of both lenses are linked by controlling the electrical signals applied to both lenses. A processing method using a charged particle beam, characterized in that the focal point in the width direction of the spot is positioned on the object to be processed by controlling the spot. (2) A quadrupole lens and an axially symmetrical lens are provided in the main body of the charged particle beam processing apparatus, and the electric signals applied to both lenses are controlled i11 in conjunction with each other, so that the spot shape of the charged particle beam becomes a line on the object to be processed. A processing device using a charged particle beam, comprising means for controlling the focal lengths of the 44fA child lens and the axially symmetrical lens in conjunction with each other so that the 44fA child lens and the axially symmetrical lens are in a state where the 44fA child lens and the axially symmetrical lens are in a state where the 44fA child lens has a shape and focuses in the width direction.