JP2020120012A - Charged particle beam lithography apparatus - Google Patents

Abstract

To suppress an electrooptical lens barrel from tilting.SOLUTION: A charged particle beam lithography apparatus according to one embodiment comprises: a stage on which an object substrate of lithography is mounted; a chamber in which the stage is arranged, and which has a carrying-in/out opening part for the stage formed in one side face and also closed with a door; and an electrooptical lens barrel arranged on the chamber. An outer surface and an inner surface of the door protrude between an upper end and a lower end of the door out of the chamber from the upper end or lower end. The upper half-side outer surface and inner surface of the door are inclined surfaces located more outward on a more lower side, and the lower half-side outer surface and inner surface are inclined surfaces located more outward on a more upper side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a charged particle beam drawing apparatus.

With the high integration of LSI, 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 particularly in a stepper or a scanner is also called a reticle). .) is reduced and transferred onto the wafer. The 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 that houses the stage, an electron beam generation source that emits an electron beam and is placed 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.

When drawing, the inside of the electron optical lens barrel and the inside of the chamber are evacuated by a vacuum pump, and drawing is performed on the sample in a vacuum. An opening having a size that allows the stage to be carried in and out is formed on a side surface of the chamber in order to install, take out, inspect, etc. the stage in the chamber. This opening is closed by a door while the chamber is evacuated. The door can be opened and closed and is fixed to the side surface with screws or the like.

When the inside of the chamber is in a vacuum state, a pressure difference is generated inside and outside the chamber, so that the chamber is slightly deformed. At that time, the amount of deformation differs between the side surface where the opening is formed and the side surface where the opening is not formed, and the electron optical lens barrel fixed to the upper surface of the chamber forms the opening with low rigidity. It is inclined to the side surface.

In order to prevent this, a strut that supports the opening is installed separately, but the pressure difference between the inside and outside of the chamber fluctuates due to fluctuations in atmospheric pressure, and the chamber deforms, so at the joint between the strut and the opening of the chamber. It is difficult to make surface contact with accuracy. Therefore, there is a problem that the tilt characteristics of the lens barrel at the surface contact portion change when the atmospheric pressure rises and when the atmospheric pressure falls.

JP, 2015-38967, A JP, 2010-219373, A JP, 2017-228633, A JP, 2006-136835, A

An object of the present invention is to provide a charged particle beam drawing apparatus that suppresses the tilt of an electron optical lens barrel.

A charged particle beam drawing apparatus according to an aspect of the present invention includes a stage on which a drawing target substrate is placed, the stage is disposed inside, and an opening for loading/unloading the stage is formed on one side surface. A chamber whose part is closed by a door; and an electron optical lens barrel disposed on the chamber, wherein the outer surface and the inner surface of the door are located between the upper end and the lower end of the door from the upper end and the lower end. It projects to the outside of the chamber.

In the charged particle beam drawing apparatus according to one aspect of the present invention, the outer surface and the inner surface of the upper half side of the door are inclined surfaces located outward toward the lower side, and the outer surface and the inner surface of the lower half side are outward toward the upper side. It is a slope located in the direction.

In the charged particle beam drawing apparatus according to the aspect of the present invention, the door is thinner than a wall surface of the chamber.

In the charged particle beam drawing apparatus according to the aspect of the present invention, a strength adjusting plate is attached to the outer surface of the door.

In the charged particle beam drawing apparatus according to the aspect of the present invention, the door projects outward from the chamber between a left end and a right end of the door, between the left end and the right end.

According to the present invention, the tilt of the electron optical lens barrel can be suppressed.

1 is a schematic view of a drawing device according to an embodiment of the present invention. It is an external view of a drawing apparatus. (A) is a perspective view of a door, (b) is a bb line sectional view of (a). It is a figure explaining the state which evacuated the inside of a chamber. It is sectional drawing of the door by a modification. It is sectional drawing of the door by a modification. It is sectional drawing of the door by a modification. It is sectional drawing of the door 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 and a control circuit 160. 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.

In the electron optical lens barrel 102, for example, 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. .. An XY stage 105 is arranged in the chamber 103. The substrate 101 to be drawn is placed on the XY stage 105. The substrate 101 includes a mask substrate, a wafer and the like.

The drawing unit 150 is controlled by the control circuit 160. Further, during the drawing process, the inside of the electron optical lens barrel 102 and the inside of the chamber 103 are evacuated by the vacuum pump 170. In order to install the XY stage 105 in the chamber 103, take out the XY stage 105, and inspect the XY stage 105, one side surface of the chamber 103 has an opening of a size that allows the XY stage 105 to be carried in and out. 20 are formed. While the vacuum is being drawn, the opening 20 is closed by a door 30 which is a separate lid. The door 30 can be opened and closed by a hinge (not shown), and when closing the opening 20, the peripheral edge is fixed to the side surface of the chamber with a bolt or the like.

The chamber 103 is provided with a first laser interferometer that measures the position in the X direction of the XY stage 105 and a second laser interferometer that measures the position in the Y direction on a side surface different from the side surface on which the opening 20 is formed. (Both are not shown).

As shown in FIG. 2, an opening 20 having a size that allows the XY stage 105 to be carried in and out is formed on one side surface 40 of the outer peripheral surface of the chamber 103. Therefore, if it is left as it is, the rigidity of the side surface 40 on which the opening 20 is formed is weaker than that on the side surface on which the opening 20 is not formed.

Therefore, in the present embodiment, as shown in FIGS. 3A and 3B, the door 30 that closes the opening 20 has a vertical cross-sectional shape (in a state where the opening 20 is closed) near the middle of the vertical direction. The shape is such that it protrudes toward the outside of the chamber. Specifically, the outer surface and the inner surface of the upper half side 30u of the door 30 are slopes that are located outward as they are lower, and the outer surface and the inner surface of the lower half side 30d are slopes that are located outward as they are upward. Has become. Note that the most projecting portion does not have to be the center between the upper end and the lower end of the door, but may be between the upper end and the lower end.

Examples of materials for the chamber 103 and the door 30 include Invar. The chamber 103 has a side surface thickness of about 80 mm, a top surface thickness of about 120 mm, and a bottom surface thickness of about 110 mm. The thickness of the door 30 is about 12 mm, which is thinner than the thickness of the wall surface of the chamber 103.

When the length of the door 30 in the vertical direction is H and the protrusion amount in the vicinity of the middle in the vertical direction is F, F/H is preferably about 0.05 to 0.1.

When the opening 20 of the side surface 40 is closed by the door 30 and the inside of the electron optical lens barrel 102 and the chamber 103 are evacuated by the vacuum pump 170, the atmospheric pressure applied to the door 30 causes the door 30 to move up and down as shown in FIG. It is converted into a force that stretches in the direction. As a result, the amounts of deformation of the side surface 40 and other side surfaces become substantially equal, and the tilt of the electron optical lens barrel 102 fixed to the chamber upper surface can be suppressed. As a result, even when there is a change in atmospheric pressure, the error in the beam position irradiated on the substrate 101 is reduced, and the drawing accuracy is improved.

By making the door 30 thinner than the wall surface (top surface, side surface, bottom surface) of the chamber 103, the rigidity of the side surface 40 in which the opening 20 is closed by the door 30 can be matched to the rigidity equivalent to other side surfaces. Therefore, the weight can be reduced.

Further, since the deformation of the side surface adjacent to the side surface 40 on which the laser interferometer is installed is also suppressed, the position of the XY stage 105 can be accurately measured, and the drawing accuracy is improved.

Like the door 30A shown in FIG. 5, the vertical middle portion may be a vertical plane 30p. Further, as shown in FIG. 6, a plate 32 for strength adjustment may be attached to the outer surface of the door 30A (or the door 30). By attaching the plate 32, the vertical extension of the door 20A (30) is suppressed.

A curved shape may be used like the door 30B shown in FIG. 7.

Like the door 30C shown in FIG. 8, it can be formed in a ridged shape (pyramidal shape) in which it protrudes outward in the vicinity of the middle of the vertical direction and the horizontal direction. That is, the door 30C has four slopes, namely, a slope 30_1 located outward toward the bottom, a slope 30_2 located outward toward the left, a slope 30_3 located outward toward the top, and a slope 30_4 located outward toward the right. It may have a slope.

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 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 opening part 30 door 40 side surface 100 drawing device 101 substrate 102 electron optical lens barrel 103 chamber 105 XY stage 150 drawing part 160 control circuit 170 vacuum pump 200 electron beam

Claims (5)

A stage for mounting the drawing target substrate,
A chamber in which the stage is disposed inside, an opening for loading and unloading the stage is formed on one side surface, and the opening is closed by a door;
An electron optical lens barrel arranged on the chamber,
Equipped with
The charged particle beam drawing apparatus according to claim 1, wherein an outer surface and an inner surface of the door project outward from the chamber between an upper end and a lower end of the door than an upper end or a lower end of the door. The outer surface and the inner surface of the upper half side of the door are slopes that are located outward toward the lower side, and the outer surface and the inner surface of the lower half side are slopes that are located outward toward the upper side. The charged particle beam drawing apparatus according to claim 1. The charged particle beam drawing apparatus according to claim 1, wherein the door is thinner than a wall surface of the chamber. The charged particle beam drawing apparatus according to any one of claims 1 to 3, wherein a strength adjusting plate is attached to an outer surface of the door. The charged particle beam drawing apparatus according to claim 1, wherein the door protrudes outward of the chamber between a left end and a right end of the door from a left end or a right end of the door.

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