JPH01227436A - Charged-particle beam lithography equipment - Google Patents

Abstract

PURPOSE:To let the vibrations of a sample-base driving motor, a ball screw, etc., escape to a floor, to inhibit the vibrations of a sample chamber and an electronic optical lens tube and to improve the accuracy of drawing and suppress the generation of the displacement of the sample chamber and a peripheral device by installing a surface plate onto the floor of a building under a condition that no displacement is generated to the floor. CONSTITUTION:In a charged-pasticle beams lithography equipment composed of a sample chamber 16 fixed onto a surface plate 11 and a charged-beam optical lens tube 17 fastened onto the sample chamber 16, said surface plate 11 is mounted on a floor 13 for a building under the state in which no displacement is generated to the floor, 13. The surface plate 11 is fixed firmly onto the floor 13 through support legs 12, and the floor 13 is connected to the structure 15 of the building through a vibrationproof mechanism 14 for preventing vibrations. A sample base on which a sample is placed is housed into the sample chamber 16, a motor 18 for drive is set up onto the surface plate 11, and the revolution of the motor 18 is transmitted over the sample base through a ball screw 19, thus moving the sample base. An inserting chamber 21 and an extracting chamber 22 for the sample are installed to the side sections of the sample chamber 16, and a pre-stage treating chamber 23 and a post- stage treating chamber 24 are fitted onto the floor 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a charged beam lithography apparatus, and particularly to a charged beam lithography apparatus that solves problems in mounting various components.

(Prior Art) Conventionally, an electron beam lithography apparatus is constructed by fixing an electron beam optical column on a sample chamber that accommodates a sample stage on which a sample is placed. In this device, when vibrations from the floor of the building propagate to the sample chamber, electron optical column, etc., the drawing accuracy decreases. For this reason, the surface plate that fixes the sample chamber is connected to the floor with a vibration isolation member (vibration isolation mechanism) such as a coil spring or air spring, and the sample chamber and electron beam optical column are separated from the floor of the building. Ta.

However, when the present inventors actually performed drawing using this type of device, the following problems became clear. That is, the motor that drives the sample stage, the ball screw that is the source of vibration, etc. are mounted on the same surface plate as the sample chamber. Since the surface plate is vibrationally isolated from the floor, these vibrations propagate through the sample chamber to the electron optical column, reducing the drawing accuracy.

Furthermore, due to the vibration isolation mechanism described above, a large displacement may occur between the floor and the sample entrance/exit of the sample chamber.

For this reason, when the loading and unloading of samples into and out of the sample chamber is automated and mechanically carried out, there is a problem in that misalignment between the sample chamber and peripheral equipment (e.g. preliminary chamber) may occur, leading to various inconveniences when loading and unloading samples. was there.

On the other hand, although it is certainly desirable to remove vibrations from the floor of a building, according to experiments conducted by the present inventors, vibrations from the motor that drives the sample stage produce better results than vibrations from the floor. It was found that this had a greater impact on accuracy. Also,
It has also been confirmed that floor vibrations can be reduced to a level that has almost no effect on drawing accuracy by making the floor or the building itself have a vibration-isolating structure.

(Issue 8 to be Solved by the Invention) As described above, conventionally, there has been a problem in which the vibrations of the motor that drives the sample stage propagate to the sample chamber, the electron optical lens barrel, etc., reducing the drawing accuracy. Furthermore, there is a problem in that displacement occurs between the sample chamber and other peripheral devices, causing inconvenience in automating the loading and unloading of samples.

The present invention has been made in consideration of the above circumstances, and its purpose is to allow vibrations of the sample stage drive motor, ball screw, etc. to escape to the floor, and to suppress vibrations of the sample chamber and electron optical column. However, it is an object of the present invention to provide a charged beam lithography apparatus that can improve the lithography precision and suppress the occurrence of displacement between the sample chamber and peripheral equipment.

[Structure of the Invention] (Means for Solving the Problems) The gist of the present invention is to release vibrations of the sample stage drive motor, ball screw, etc. to the floor by directly fixing the surface plate to the floor.

That is, the present invention provides a charged beam lithography apparatus consisting of a sample chamber fixed on a surface plate and a charged beam optical column fixed on the sample chamber, in which the surface plate is moved to the floor of a building and caused to be displaced. More preferably, the floor of the building has a vibration-isolated structure or a structure isolated from other sources of vibration.

Further, the present invention provides a surface plate, a sample chamber that accommodates a sample stage on which a sample is placed and is fixed on the surface plate, a charged beam optical column fixed on the sample chamber, and a sample chamber that is connected to the sample chamber. In a charged beam lithography device that draws a desired pattern on a sample while continuously moving a sample stage, the surface plate and peripheral devices are placed on the floor of a building in a state that does not cause displacement. The protection bed has a vibration-isolated structure or a structure that is isolated from other vibration sources.

(Function) According to the present invention, by fixing the surface plate on which the vibration generation source such as a motor and the sample chamber are directly fixed to the floor without using a vibration isolating mechanism, the sample chamber and the electron optical column can be fixed directly to the floor. Vibration can be reduced and relative displacement between the floor and the sample chamber can be almost eliminated.

G is the acceleration of the vibration generated by the motor, etc., and M is the mass of the surface plate.
If the mass of one motor is m, if the surface plate and the floor are isolated from vibration, the vibration acceleration of the surface plate will be G This is a value that cannot be ignored by devices that draw while drawing. On the other hand, if the surface plate and the floor are fixed with high rigidity, and the mass of the floor is Mo, the vibration acceleration mentioned above is GxM+m+Y,...
- (2), and the vibration is smaller than in the case described above.

That is, it becomes possible to release vibrations to the floor. Here, Mo is generally much larger than M and m, and (2
) is much smaller than the value obtained from equation (1).

Furthermore, in order to improve the vibration isolation effect, if the spring constant of the vibration isolation coil spring or the like is made small, a large displacement will occur even when a slight force (for example, when the sample stage reciprocates) is applied. However, if the surface plate and the floor are directly installed without using a vibration isolation mechanism, such displacement naturally does not occur.

(Example) Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a schematic configuration diagram showing an electron beam lithography apparatus according to an embodiment of the present invention. In the figure, reference numeral 11 denotes a surface plate, and this surface plate 11 is firmly fixed to a floor 13 via support legs 12. The floor 13 is connected to a building structure 15 via a vibration isolation mechanism 14 for vibration isolation. That is, the surface plate 11 is installed on the floor 13 having a vibration-isolating structure without being displaced from the guard bed 13.

A sample chamber 16 is installed above the surface plate 11, and an electron beam optical column 17 is installed above this sample chamber 16. The sample chamber 16 accommodates a sample (not shown) and a sample stage on which the sample is placed. Further, a drive motor 18 is installed on the surface plate 11, and this motor 18
The rotation of is transmitted to the sample stage via the ball screw 19, thereby causing the sample stage to move. Further, a sample insertion chamber 21 and a sample extraction chamber 22 are installed on the side of the sample chamber 16.

On the other hand, above the floor 13, a pre-processing chamber 23 and a post-processing chamber 24 are installed. The pre-processing chamber 23 performs predetermined processing on the sample before drawing, and is connected to the insertion chamber 21 via a connecting portion 25 . The post-processing chamber 24 performs predetermined processing on the sample after drawing, and the connecting section 2
6 to the extraction chamber 22. The sample to be drawn is transported from the pre-processing chamber 23 into the insertion chamber 21, and further transported and placed on the sample stage 16 in the sample chamber 16. The drawn sample is then transported into the take-out chamber 22 and further into the subsequent processing chamber 24.

With this configuration, the surface plate 11 is directly fixed to the floor 13 without using a vibration isolation mechanism, so vibrations caused by the drive of the motor 18 are transmitted to the floor 13 via the surface plate 11. Therefore, vibration can be reduced. That is, since the surface plate 11 and the floor 13 are fixed with high rigidity, the acceleration caused by the vibration of the motor 18 can be sufficiently reduced as shown in equation (2) above. In fact, when we measured vibrations while continuously moving the sample stage in the same way as when drawing, we found that the vibrations on the surface plate 11 were approximately 30% lower than in the conventional example in which the surface plate 11 was fixed to the floor 13 via a vibration isolation mechanism. It decreased by 2/3. This effect is particularly effective in a method in which drawing is performed while continuously moving the sample stage.

Furthermore, since the surface plate 11 is fixed to the floor 13 with high rigidity, the sample chamber 16 (in this case, each chamber 21, 22 fixed to the sample chamber 16), and the pre- and post-processing chambers 23.
It is possible to eliminate the occurrence of misalignment with 24. Contains, accumulates,
Even if the sample transportation is automated, no inconvenience will occur.

Furthermore, by making the method itself have an anti-vibration structure as in the example, it was possible to draw normally even when large vibrations occurred in the building due to an earthquake or the like.

Note that the present invention is not limited to the embodiments described above. For example, the floor does not necessarily have to have an anti-vibration structure, and the building itself may have an anti-vibration structure. Additionally, the present invention is most effective in a method in which drawing is performed while the sample stage is continuously moved, but even if it is not a continuous movement method, it is possible to suppress vibration by driving the sample stage by a motor, etc. The effect of In addition to J electron beam lithography equipment,
It is also possible to apply it to an ion beam drawing device.

In addition, various modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

As described in detail above, according to the present invention, the surface plate on which the sample chamber and the charged beam optical column are installed is fixed to the floor of the building without using a vibration isolation mechanism, so that the sample stage drive motor and The vibrations of the ball screw, etc. can be released to the floor, and the vibrations of the sample chamber and charged beam optical column can be suppressed. Therefore, it is possible to improve the drawing accuracy, and furthermore, it is possible to suppress the occurrence of displacement between the sample chamber and the peripheral equipment.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an electron beam lithography apparatus according to an embodiment of the present invention. 11... Surface plate, 12... Support leg, 13... Floor, 1
4... Vibration isolation mechanism, 15... Building structure, 16...
- Sample chamber, 17... Electron optical lens barrel, 18... Drive motor, 19... Ball screw, 21... Insertion chamber, 22... Extraction chamber, 23... Pre-processing chamber, 23... Post-processing chamber, 25.26... Connection section. Applicant's agent Patent attorney Takehiko Suzue

Claims (3)

[Claims] (1) In a charged beam lithography system consisting of a sample chamber fixed on a surface plate and a charged beam optical column fixed on the sample chamber, the surface plate is in a state in which there is no displacement with respect to the floor of the building. A charged beam lithography device characterized by being installed in. (2) The charged beam lithography apparatus according to claim 1, wherein the floor of the building has a vibration-isolating structure or a structure isolated from other vibration sources. (3) A surface plate, a sample chamber that accommodates a sample stage on which the sample is placed and is fixed on the surface plate, a charged beam optical column fixed on this sample chamber, and a sample chamber that is connected to the sample chamber. In the charged beam lithography device, which draws a desired pattern on a sample while continuously moving a sample stage, the surface plate and the peripheral device are installed on a floor of a building in a state where they are not displaced from the floor; A charged beam lithography apparatus characterized in that the floor has a vibration-isolated structure or a structure isolated from other vibration generating sources.