JP7271978B2 - Stage device and charged particle beam processing device - Google Patents

Description

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

2. Description of the Related Art As LSIs become highly integrated, circuit line widths required for semiconductor devices are becoming finer year by year. In order to form a desired circuit pattern on a semiconductor device, a reduction projection type exposure apparatus is used to form a highly accurate original image pattern (a mask, or a reticle for those used particularly in steppers and scanners) formed on quartz. ) is transferred onto the wafer in a reduced size. A high-precision original image pattern is drawn by an electron beam drawing apparatus using a so-called electron beam lithography technique.

A conventional electron beam writing apparatus includes a stage on which a sample on which a pattern is to be written is placed, a chamber that houses the stage, an electron beam generation source that is arranged on the top plate of the chamber and emits an electron beam, and a sample. an electron optical column having an electron beam control system for forming an electron beam to draw a desired pattern at a desired position on the electron optical column;

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 placed on the inclined surface via rollers, and a pedestal placed on the table and on which the 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 leaf springs. Therefore, when the XY stage accelerates or decelerates, a force in the pitching direction acts on the pedestal, and the pedestal may be tilted. If the pedestal is tilted, the focus position of the electron beam and the position of the sample in the height direction will deviate from each other, degrading the drawing accuracy.

If the motion acceleration of the XY stage is lowered in order to suppress the inclination of the pedestal, there is a problem that the drawing throughput is lowered.

JP 2005-25695 A JP 2007-142292 A Japanese Patent Application Laid-Open No. 2001-116867

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

A stage device according to an aspect of the present invention is a stage device on which a substrate is placed, comprising a horizontally movable XY stage and a vertically movable Z stage on which the substrate is placed. , wherein the Z stage includes a base installed on the XY stage, a fixed part vertically installed from the base, a table installed above the base, and the fixed part pressing the table. a leaf spring connected and fixed to the plate spring, 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; It has

A stage device according to an aspect of the present invention further includes a tilting table that is installed on the base and has a tilted surface, and rollers that are arranged between the tilted surface and the table.

In the stage apparatus according to one aspect of the present invention, the leaf springs to which the piezoelectric elements are attached are installed on each side of the rectangular table.

In the stage device according to one aspect of the present invention, the piezoelectric element is attached to both surfaces of the leaf spring.

A charged particle beam processing apparatus according to an 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 diagram of a rendering device according to an embodiment of the invention; FIG. It is a schematic diagram of a stage device according to the same embodiment. (a) and (b) are diagrams showing an actuator provided on a plate spring. It is a figure which shows the installation example of a leaf|plate spring and an actuator. It is a figure which shows the installation example of a leaf|plate spring and an actuator. FIG. 4 is a diagram showing an example of a command method for command voltages to actuators; FIG. 4 is a diagram showing an example of a command method for command voltages to actuators; FIG. 4 is a diagram showing an example of how an actuator is attached to a leaf spring; It is a schematic diagram of a stage device according to a modification.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. In the embodiment, a configuration using an electron beam as an example of a charged particle beam will be described. 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 apparatus according to an embodiment of the present invention. As shown in FIG. 1, the drawing apparatus 100 includes a drawing section 150, a control circuit 160, a stage control circuit 170, and a displacement control circuit 180. FIG. A drawing apparatus 100 draws a pattern on a substrate 101 coated with a resist using an electron beam 200 . The drawing unit 150 has an electron optical lens barrel 102 and a chamber (drawing room) 103 . Electron optical lens barrel 102 is arranged on 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 . A control circuit 160 controls the operation of each part in the electron optical lens barrel 102 . 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. A substrate 101 to be drawn is placed on the Z stage 30 . The substrate 101 includes a mask substrate, a wafer, and the like. A stage control circuit 170 controls the acceleration of the XY stage 20 and the height of the Z stage 30 .

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

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

After passing through the second aperture 206, the electron beam 200 is focused by the objective lens 207, deflected by the deflector 208, and reaches the target position of the substrate 101 on the Z stage 30 mounted on the continuously moving XY stage 20. be irradiated. A desired pattern is thus 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 fixed portion 32 vertically provided from the periphery of the base 31, an inclined table 33 having an inclined surface, and rollers 34. and a pedestal 36 which is set 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 inclined table 33 and the roller 34 changes, the position of the table 35 changes in the height direction, and the height of the substrate 101 can be adjusted.

Note that 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 rollers 34, as shown in FIG. By changing the height of the table 35, the height of the substrate 101 may be adjusted.

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

When the XY stage 20 on which the Z stage 30 is mounted is accelerated or decelerated, a force in the pitching direction acts on the pedestal 36 and the leaf spring 40 is bent (curved), and the pedestal 36 may be tilted. Therefore, in this embodiment, the force acting on the pedestal 36 is estimated based on the acceleration of the XY stage 20, and the force in the opposite direction is applied by the actuator 50 to keep the pedestal 36 horizontal.

The displacement control circuit 180 acquires 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 voltage to the actuator 50 so that the pedestal 36 is kept horizontal. As shown in FIG. 3( a ), when a voltage is applied to compress the actuator 50 , an upward force is applied to the leaf spring 40 . As shown in FIG. 3B, when a voltage is applied to extend the actuator 50, a downward force is applied to the leaf spring 40. As shown in FIG.

Since the pedestal 36 may be swayed by pitching and rolling in the stage traveling direction (eg, X direction), it is preferable to install the leaf spring 40 and the actuator 50 so as to suppress these swaying.

For example, as shown in FIG. 4, leaf springs 40 and actuators 50 are installed on each of four sides (two opposing sides in the X direction and two opposing sides in the Y direction) of a 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 of the two opposing sides in the X direction and at one location on the other side.

The method of 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. 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.

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

As described above, according to the present embodiment, by applying voltage to the actuator 50 based on the acceleration of the XY stage 20 and applying force to the leaf spring 40, the base 36 can be kept horizontal. Therefore, the focus position of the electron beam and the position in the height direction of the substrate 101 can be easily matched, and the drawing accuracy is improved. In addition, since it is not necessary to lower the motion 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.

Further, in these embodiments, an electron beam writing apparatus was used as an example, but similar effects can be obtained with any apparatus in which the beam is affected by a magnetic field. It can be used for a processing device such as an inspection device in addition to the drawing device.

It should be noted that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the present invention at the implementation stage. Further, various inventions can be formed by appropriate combinations of the plurality of constituent elements disclosed in the above embodiments. For example, some components may be omitted from all components shown in the embodiments. Furthermore, components across different embodiments may be combined as appropriate.

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,
a horizontally movable XY stage;
a Z stage movable in a vertical direction and on which the substrate is mounted;
with
The Z stage is
a base installed on the XY stage;
a fixed portion vertically provided from the base;
a table placed above the base;
a leaf spring that presses the table and connects and fixes it to the fixing part;
a piezoelectric element that is attached to the plate spring and that expands or contracts when a voltage is applied from the outside based on the acceleration of the XY stage;
a pedestal installed on the table and on which the substrate is placed;
A stage device characterized by comprising: a tilting table installed on the base and having a tilting surface;
a roller disposed between the inclined surface and the table;
2. The stage apparatus according to claim 1, further comprising: 3. The stage apparatus according to claim 1, wherein the leaf springs to which the piezoelectric elements are attached are installed on each side of the rectangular table. 4. A stage apparatus according to claim 1, wherein said piezoelectric element is attached to both sides of said leaf spring. Having 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 that causes the piezoelectric element to expand or contract by applying a voltage based on the acceleration of the XY stage to the piezoelectric element .

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