JP2020126941A - Stage device and charged particle beam processing device - Google Patents

Abstract

To prevent a pedestal of a Z stage from tilting while suppressing a decrease in drawing throughput.SOLUTION: A stage device according to an embodiment of the present invention on which a substrate is placed includes an XY stage that can horizontally move, and a Z stage on which the substrate is placed and which is movable in the vertical direction. The Z stage includes a base installed on the XY stage, a fixed portion hung from the base, a table installed above the base, a leaf spring that presses the table to connect and fix the table to the fixing portion, a piezoelectric element that is attached to the leaf spring and to which a voltage is applied on the basis of the acceleration of the XY stage, and a pedestal which is installed on the table and on which the substrate is placed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a stage device and a charged particle beam processing device.

With the high integration of LSIs, the circuit line width required for semiconductor devices has been miniaturized year by year. In order to form a desired circuit pattern on a semiconductor device, a reduction projection type exposure apparatus is used, and a high-precision original image pattern formed on quartz (a mask, or one used especially in a stepper or a scanner is also called a reticle). .) is reduced and transferred onto the wafer. A high-precision original image pattern is drawn by an electron beam drawing device, and so-called electron beam lithography technology is used.

A conventional electron beam drawing apparatus includes a stage on which a sample on which a pattern is drawn is placed, a chamber for housing the stage, an electron beam generation source for emitting an electron beam, which is arranged on a top plate of the chamber, and a sample. And an electron optical lens barrel having an electron beam control system for forming an electron beam in order to draw a desired pattern at a desired position above.

The stage on which the sample is placed has an XY stage movable in a direction orthogonal to the optical axis direction of the electron beam, and a Z stage mounted on the XY stage and movable in the optical axis direction. For example, the Z stage has an inclined table having an inclined surface, a table installed on the inclined surface via a roller, and a pedestal installed on the table and on which a sample is placed. When the roller rotates and the contact point between the inclined surface and the roller changes, the position of the table in the height direction changes.

The table of the Z stage is pressed by a leaf spring. Therefore, when the XY stage is accelerated or decelerated, a force in the pitching direction acts on the pedestal and the pedestal may tilt. When the pedestal is tilted, the focus position of the electron beam is displaced from the position in the height direction of the sample, which deteriorates the drawing accuracy.

When the operation acceleration of the XY stage is reduced in order to suppress the inclination of the pedestal, there is a problem that the drawing throughput is reduced.

JP, 2005-25695, A JP, 2007-142292, A JP 2001-116867 A

It is an object of the present invention to provide a stage device and a charged particle beam processing device that prevent the pedestal of the Z stage from tilting while suppressing a decrease in throughput.

A stage device according to one aspect of the present invention is a stage device on which a substrate is placed, and includes an XY stage that is horizontally movable, and a Z stage that is vertically movable and on which the substrate is placed. And the Z stage includes a base installed on the XY stage, a fixing unit vertically extending from the base, a table installed above the base, and the fixing unit pressing the table. A leaf spring fixed to the leaf spring, a piezoelectric element attached to the leaf spring to which a voltage is applied based on the acceleration of the XY stage, and a pedestal placed on the table on which the substrate is placed, Is to have.

The stage apparatus according to an aspect of the present invention further includes a tilt table installed on the base and having a tilted surface, and a roller arranged between the tilted surface and the table.

In the stage device according to an aspect of the present invention, the leaf springs to which the piezoelectric element is attached are installed on each side of the rectangular table.

In the stage device according to the aspect of the present invention, the piezoelectric elements are attached to both surfaces of the leaf spring.

The charged particle beam processing apparatus according to one aspect of the present invention irradiates a charged particle beam while moving the substrate by the XY stage, and applies a voltage based on the acceleration of the XY stage to the piezoelectric element.

According to the present invention, it is possible to prevent the pedestal of the Z stage from tilting while suppressing a decrease in throughput.

1 is a schematic view of a drawing device according to an embodiment of the present invention. It is a schematic diagram of a stage device concerning the embodiment. (A) (b) is a figure which shows the actuator provided in the leaf spring. It is a figure which shows the installation example of a leaf spring and an actuator. It is a figure which shows the installation example of a leaf spring and an actuator. It is a figure which shows the example of the command method of the command voltage to an actuator. It is a figure which shows the example of the command method of the command voltage to an actuator. It is a figure which shows the example of attachment of the actuator to a leaf spring. It is a schematic diagram of a stage device by a modification.

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to the electron beam, and may be an ion beam or the like.

FIG. 1 is a schematic diagram showing the configuration of a drawing device according to an embodiment of the present invention. As shown in FIG. 1, the drawing apparatus 100 includes a drawing unit 150, a control circuit 160, a stage control circuit 170, and a displacement control circuit 180. The drawing apparatus 100 uses the electron beam 200 to draw a pattern on the substrate 101 coated with the resist. The drawing unit 150 has an electron optical lens barrel 102 and a chamber (drawing chamber) 103. The electron optical lens barrel 102 is arranged on the chamber 103.

An electron gun 201, an illumination lens 202, a first aperture 203, a projection lens 204, a deflector 205, a second aperture 206, an objective lens 207, and a deflector 208 are provided in the electron optical lens barrel 102. The operation of each unit in the electron optical lens barrel 102 is controlled by the control circuit 160. A stage device is arranged in the chamber 103. The stage device includes an XY stage 20 and a Z stage 30 mounted on the XY stage. The XY stage 20 is movable in a direction (horizontal direction) orthogonal to the optical axis direction of the electron beam 200, and the Z stage 30 is movable in the optical axis direction which is the vertical direction. On the Z stage 30, the substrate 101 to be drawn is placed. The substrate 101 includes a mask substrate, a wafer and the like. The stage control circuit 170 controls the acceleration of the XY stage 20 and the height of the Z stage 30.

The electron beam 200 emitted from the electron gun 201 (emitter) is applied to the entire first aperture 203 having an opening by the illumination lens 202. The electron beam 200 is shaped into, for example, a rectangle by passing through the opening of the first aperture 203.

The electron beam 200 that has passed through the first aperture 203 is projected by the projection lens 204 onto the second aperture 206 having an opening. At this time, the deflector 205 controls the deflection of the beam position projected on the second aperture 206, so that the shape and size of the electron beam can be changed (variable shaping).

The electron beam 200 that has passed through the second aperture 206 is focused by the objective lens 207, is deflected by the deflector 208, and is moved to the target position of the substrate 101 on the Z stage 30 mounted on the XY stage 20 that moves continuously. Is irradiated. As a result, a desired pattern is drawn on the substrate 101.

As shown in FIG. 2, the Z stage 30 includes a base 31 installed on the XY stage 20, a fixing portion 32 vertically extending from a peripheral portion of the base 31, an inclined table 33 having an inclined surface, and a roller 34. It has a table 35 installed on the inclined surface of the inclined table 33 via the, and a pedestal 36 installed on the table 35 and on which the substrate 101 is placed. When the roller 34 rotates and the contact point between the inclined surface of the tilt table 33 and the roller 34 changes, the position of the table 35 in the height direction changes, and the height of the substrate 101 can be adjusted.

The mechanism for adjusting the height of the substrate 101 is not limited to that shown in FIG. For example, instead of the tilt table 33 and the rollers 34, as shown in FIG. 9, an actuator (piezoelectric element) 37 that moves up and down and a mover 38 support the table 35, and the actuator 37 moves the mover 38 up and down. By doing so, the height of the table 35 may be changed to adjust the height of the substrate 101.

The table 35 is pressed by a damper including a leaf spring 40, and is connected and fixed to the upper end of the fixing portion 32. An actuator (piezoelectric element) 50 such as a macro fiber composite (MFC) is attached to the leaf spring 40. The displacement control circuit 180 applies a voltage to the actuator 50 to cause displacement (compression/expansion).

When the XY stage 20 equipped with the Z stage 30 is accelerated or decelerated, a force in the pitching direction acts on the pedestal 36 to bend (bend) the leaf spring 40, and the pedestal 36 may tilt. Therefore, in the present embodiment, the force acting on the pedestal 36 is estimated based on the acceleration of the XY stage 20, and a reverse force is applied by the actuator 50 to keep the pedestal 36 horizontal.

The displacement control circuit 180 acquires the acceleration information of the XY stage 20 from the control signal output to the XY stage 20 by the stage control circuit 170, and applies a voltage to the actuator 50 so that the pedestal 36 keeps horizontal. As shown in FIG. 3A, when a voltage that causes the actuator 50 to compress is applied, an upward force is applied to the leaf spring 40. As shown in FIG. 3B, when a voltage that causes the actuator 50 to extend is applied, a downward force is applied to the leaf spring 40.

Pitching and rolling sway may occur on the pedestal 36 in the stage moving direction (for example, the X direction), and therefore it is preferable to install the leaf spring 40 and the actuator 50 so as to suppress these.

For example, as shown in FIG. 4, the leaf spring 40 and the actuator 50 are installed on each of four sides (two sides facing each other in the X direction and two sides facing each other in the Y direction) of the rectangular table 35. Alternatively, as shown in FIG. 5, the leaf spring 40 and the actuator 50 may be installed at two locations on one side and one location on the other side of the two opposite sides in the X direction.

The method for controlling the voltage (command voltage) applied to the actuator 50 by the displacement control circuit 180 is not particularly limited. For example, as shown in FIG. 6, the displacement of the actuator 50 is measured by the sensor 190, and the target value of the displacement and the current value are measured. A combination of feedback control and feedforward control that controls the applied voltage based on the difference from the value and the stage acceleration information can be applied.

Moreover, as shown in FIG. 7, the applied voltage may be controlled by measuring the stage position using a laser interferometer 192 and using the stage pitching amount as a disturbance observer.

As described above, according to the present embodiment, the pedestal 36 can be kept horizontal by applying a voltage to the actuator 50 and applying a force to the leaf spring 40 based on the acceleration of the XY stage 20. Therefore, the focus position of the electron beam and the position of the substrate 101 in the height direction are easily aligned, and the drawing accuracy is improved. Further, since it is not necessary to reduce the operation acceleration of the XY stage 20, it is possible to prevent a decrease in drawing throughput.

In the above embodiment, an example in which the actuator 50 is attached to one surface of the leaf spring 40 has been described, but the actuator 50 may be attached to both surfaces of the leaf spring 40 as shown in FIG. 8.

Further, in these embodiments, the electron beam drawing apparatus has been described as an example, but the same effect can be obtained as long as the apparatus is a device whose beam is affected by a magnetic field. Besides the drawing device, it can be used for a processing device such as an inspection device.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements within a range not departing from the gist of the invention in an implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the constituent elements of different embodiments may be combined appropriately.

20 XY stage 30 Z stage 40 leaf spring 50 actuator 100 drawing device 101 substrate 102 electron optical lens barrel 103 chamber 150 drawing unit 160 control circuit 170 stage control circuit 180 displacement control circuit

Claims (5)

A stage device on which a substrate is placed,
An XY stage that can move horizontally
A Z stage that is vertically movable and on which the substrate is placed;
Equipped with
The Z stage is
A base installed on the XY stage,
A fixed portion hung from the base,
A table installed above the base,
A leaf spring that presses the table to connect and fix the table to the fixing portion;
A piezoelectric element attached to the leaf spring, to which a voltage is applied based on the acceleration of the XY stage;
A pedestal installed on the table and on which the substrate is placed,
A stage device comprising: An inclined table installed on the base and having an inclined surface,
A roller arranged between the inclined surface and the table;
The stage apparatus according to claim 1, further comprising: The stage device according to claim 1 or 2, wherein the leaf spring to which the piezoelectric element is attached is installed on each side of the rectangular table. The stage device according to claim 1, wherein the piezoelectric elements are attached to both surfaces of the leaf spring. It has the stage device according to any one of claims 1 to 4,
Irradiating a charged particle beam while moving the substrate by the XY stage,
A charged particle beam processing apparatus, wherein a voltage based on the acceleration of the XY stage is applied to the piezoelectric element.

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