JPH03106014A - Charged particle beam lithography device - Google Patents

Abstract

PURPOSE:To make it possible to conduct a high speed patterning at a higher velocity by a method wherein a first and a second memories, in which the setting time to be used for high precision and high speed is stored respectively, are provided, either of the memories is selected, the setting time is read out, and the blanking of a charged particle beam is conducted. CONSTITUTION:There are two types of patterning according to the intended purposes, namely, one type is the case where high precision is required, and the other type is the case where precision is not required so much, but high speed is required rather than precision. A first memory 17, in which the setting time for high precision is stored, and a second memory 18, in which the setting time for high speed is stored, are provided and either one of memories is selected according to the intended purpose. When a highly precise patterning is conducted, a relatively longer setting time is read out from the first memory 17, and when a high speed patterning is conducted, a relatively shorter setting time is read out from the second memory 18, and the blanking of a charged particle beam is conducted. As a result, a high speed patterning can be conducted at a higher velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a charged particle beam lithography apparatus such as an electron beam lithography apparatus used in the process of manufacturing semiconductor devices and the like.

(Prior Art) In a drawing device such as an electron beam drawing device, a pattern is drawn roughly as follows.

(2) Blanking the electron beam, during which time a deflection signal corresponding to the drawing pattern is supplied to a positioning deflector that determines the position of the electron beam on the material.

This deflection signal is supplied through a deflection circuit such as a DA converter or a deflection amplifier, but it is necessary to set the signal to this DA converter or amplifier, and then to receive an accurate signal to the deflector. requires a certain amount of time (settling time), so the electron beam is blanked for this settling time. That is, if the electron beam is not blanked during the settling time, a locus of movement of the electron beam will be drawn on the material.

■ After the settling time of the DA converter and amplifier has passed,
The blanking state of the electron beam is released and the electron beam is shot onto the material. This shot time is determined by the type of resist on the material and the current density of the electron beam.

- When the electron beam shot for a specific pattern is completed, the electron beam is blanked again, and during this time the deflection signal for drawing the next pattern is set.

(Problems to be Solved by the Invention) In such a drawing method, the time required for drawing is the cheek settling time, that is, the sum of the blanking time and the shot time. It is desired that this drawing time be shortened in order to improve the productivity of semiconductor devices and masks. In the invention of the earlier application (Japanese Patent Application No. 59-92533), it was discovered that the settling time corresponds to the distance between the pattern to be drawn and the pattern drawn before it, and When drawing on a computer, calculate the distance between the pattern you are about to draw and the pattern drawn before it, and calculate the required settling time from this distance. is read from the table, and the electron beam is blanked based on the read settling time. By doing this, the blanking of the electron beam will be performed during the true settling time, and the blanking of the electron beam will not be performed even after the signal has been set to the deflection circuit. will be resolved.

According to the invention of this earlier application, the blanking of the electron beam is
This is done accurately according to the settling time of the deflection circuit, and as a result, the total drawing time can be shortened. However, there is a growing demand for further reduction in drawing time.

The present invention has been made in view of these points, and its purpose is to provide a charged particle beam lithography system that can further shorten the lithography time, which is the sum of the electron beam blanking time and the electron beam shot time. It's about making it happen.

(Means for Solving the Problems) A charged particle beam drawing apparatus based on the present invention includes means for focusing a charged particle beam on a material to be drawn, means for blanking the charged particle beam, and A deflection means for controlling the irradiation position of the particle beam, a deflection circuit including a DA converter and a deflection amplifier for supplying a deflection signal to the deflection means, a specific pattern writing position on the material, and a deflection circuit for controlling the irradiation position of the particle beam. a difference signal generation circuit for determining the difference between the desired pattern drawing position, a first memory in which a high-precision settling time table is stored, and a second memory in which a high-speed settling time table is stored. When performing high-precision drawing, a predetermined settling time is read from the first memory using the difference signal from the difference signal generation circuit.
The blanking time of the charged particle beam is controlled according to the read settling time, and during high-speed writing, a predetermined settling time is read from the second memory using the difference signal from the difference signal generation circuit. , the blanking time of the charged particle beam is controlled according to the read settling time.

(Function) There are cases where high accuracy is required for drawing depending on the purpose, and
There are cases where not so much precision is required, but rather high speed. Equipped with a first memory that stores a settling time for high precision and a second memory that stores a settling time for high speed, either memory can be selected depending on the purpose and used for high precision drawing. reads a relatively long settling time from the first memory, and during high-speed writing, reads a relatively short settling time from the second memory to blank the charged particle beam, and performs high-speed writing. Allows drawing to be performed at higher speeds.

(Implementation F!AJ) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an electron beam drawing apparatus based on the present invention, and 1 is an electron gun. The electron beam EB generated from the electron gun 1 is shaped into an electron beam with a predetermined cross-sectional shape by a well-known beam shaping means 6 consisting of a first slit 2, a second slit 3, a focusing lens 4, and a deflector 5. It is said that This beam shaping means 6 projects the image of the first slit 2 onto the second slit 3 using a focusing lens 4, and changes the position of the first slit image on the second slit 3 using a deflector 5. By doing so, a beam with an arbitrary cross-sectional shape can be made to look impressive. The oval beam is
The image is projected onto the drawing material 8 by the focusing lens 7,
The irradiation position of the electron beam on the material 8 is changed by a signal applied to the deflector 9.

A blanking means 12 comprising a blanking electrode 10 and an aperture plate 11 is provided between the electron gun 1 and the beam shaping stage 6. In this blanking means 12, the electron beam EB is deflected by applying a blanking signal to the blanking electrode 10, and the electron beam is prevented from advancing to the beam shaping means 6 by the aperture plate 11.

An electron beam deflection signal to the deflector 9 for drawing a specific pattern is set as a pattern position signal in the register 13 from a drawing controller (not shown). The signal set in the register 13 is applied to the deflector 9 via a DA converter 14 and an amplifier 15. A blanking signal to the blanking means 6 is supplied from a blanking signal generation circuit 16. Blanking signal generation same path 16
One of the settling times read out from the first memory 17 and the second memory 1'8, each storing a different settling time table, is selected and supplied by one switch circuit. . switch circuit 1
One is controlled by the controller 20, which controls the register 13, the register 21, the subtraction circuit 22, and the first and second memories 17 and 18. A signal corresponding to the position of the pattern to be drawn is supplied to the register 13, and the signal set in the register 13 is supplied to the DA converter 14 and also to the subtraction circuit 22. The calculation result of the subtraction circuit 22 is supplied to the controller 20.

Drawing of a pattern in the above-described configuration is performed as follows. First, in order to define a specific pattern t1i, a deflection signal is supplied to the deflector 5 of the beam shaping means 6 to shape the cross-sectional shape of the electron beam according to the pattern.
The material 8 is irradiated with an electron beam having a predetermined cross-sectional shape. At the same time, based on the drawing data, register 1
3, a signal corresponding to the position on the material 8 to which the electron beam is to be irradiated is set. The set signal is the DA converter]
4 is converted into an analog signal, amplified by an amplifier 15, and applied to the deflector 9 of the positioning device 2. As a result, the electron beam with a predetermined cross-sectional shape is
is irradiated to a predetermined position.

When a particular pattern has been drawn and you want to draw the next pattern at a different position on the material, first, the controller 2
By the command from 0, the position signal of the already drawn pattern set in the register 13 is set in the register 21, and the contents of the register 3 are cleared. Thereafter, a signal corresponding to the drawing position of the next pattern is set in the register 13. The signal set in this register 13 is supplied to the DA converter 14, and furthermore, the signal set in this register 13, together with the signal set in the register 21, is supplied to a subtraction circuit 22. The calculation result of the subtraction circuit 22 is supplied to the first memory 17 and the second memory 18 via the controller 20.

The first memory 17 and the second memory 18 store the difference between the position of the pattern drawn immediately before and the position of the next pattern to be drawn, that is, a settling time corresponding to the distance between the two patterns. .

Based on the calculation result of the subtraction circuit 22, a time corresponding to the distance is read from the settling time table stored in the first memory 17 and the second memory 18, and the read time signal is sent to the switch circuit. Supplied in one.

Note that the first memory 17 stores a settling time when performing high-precision drawing, and this time is
After the signal is set in register] 3, DA converter 1
4 and the amplifier 15 are sufficiently stabilized. The second memory 18 stores a settling time for high-speed drawing, but this time is shorter than the settling time stored in the first memory 17.

In the case of high-precision drawing, the controller 20 switches the switch circuit 19 and controls the settling time from the first memory 17 to be supplied to the blanking signal generation circuit 16. As a result, a relatively long blanking signal is supplied to the blanking electrode 10 of the blanking means 12 to blank the electron beam until the DA converter 14 and amplifier 15 operate stably. be done. On the other hand, in the case of high-speed drawing, since very high precision drawing is not required, the controller 20 switches the switch circuit 19 so that the settling time from the second memory 18 is supplied to the blanking signal generation circuit 16. Control as follows. As a result, the blanking electrode 10 of the blanking means 12 is supplied with a relatively short blanking signal. Therefore, during high-speed writing, even if the DA converter 14 and amplifier 15 are in a somewhat unstable state, the blanking state is canceled and the electron beam writing is performed, reducing the total writing time. It can be further shortened.

Although the present invention has been described above, the present invention is not limited to this embodiment. For example, although an electron beam lithography apparatus has been described as an example, the present invention can also be applied to an ion beam lithography apparatus. Furthermore, although two types of settling time tables are prepared, one for high-precision drawing and one for high-speed drawing, three or more tables may be provided and selected from them depending on the type of drawing.

(Effects of the Invention) As explained above, the present invention includes a first memory that stores a settling time for high precision and a second memory that stores a settling time for high speed. , select one memory and when drawing with high precision,
The configuration is such that a relatively long settling time is read from the first memory, and during high-speed writing, a relatively short settling time is read from the second memory to perform blanking of the charged particle beam. , high-speed drawing can be performed at higher speeds.

[Brief explanation of drawings]

The accompanying drawings are diagrams showing an electron beam lithography apparatus that is an embodiment of the present invention. 1... Electron gun 2... First slit 3.
...Second slit 4...Focusing lens 5...Deflector 6...Beam shaping means 7...Focusing lens 8...Material to be drawn 9...Deflector 1
0...Blanking electrode 11...Averture plate 12...Blanking means 13...Resistor 14...DA converter 15.
...Amplifier 16...Blanking signal generation circuit 17.18...Memory 19...Switch circuit 20
...Controller 21...Register 22...Subtraction circuit

Claims (1)

[Claims] means for focusing the charged particle beam onto a material to be imaged; means for blanking the charged particle beam; deflection means for controlling the irradiation position of the charged particle beam on the material; and a deflection signal for providing a deflection signal to the deflection means. A deflection circuit consisting of a DA converter and a deflection amplifier for supplying a signal, a difference signal generation circuit for determining the difference between a specific pattern writing position on the material and the next pattern writing position to be written, and a high-precision settling It is equipped with a first memory in which a time table is stored and a second memory in which a high-speed settling time table is stored. During high-precision drawing, the difference signal from the difference signal generation circuit is used to control the first memory. A predetermined settling time is read from the memory of the charged particle beam, and the blanking time of the charged particle beam is controlled according to the read settling time. During high-speed writing, the blanking time of the charged particle beam is 2
A charged particle beam lithography apparatus configured to read a predetermined settling time from a memory and control a blanking time of a charged particle beam according to the read settling time.