JPH08320570A - Electron beam plotting device - Google Patents

Abstract

PURPOSE: To effectively improve supporting strength by supporting an objective lens main body at two points on a sample chamber by a beam. CONSTITUTION: The upper end of the objective lens 2 of an electron beam column 1 is fixed by the beam 3 to the sample chamber 5. By fixing the lower end of the lens 2 on the sample chamber 5, the lens 2 is supported at two points, thereby preventing rolling. Namely, the beam 3 whose angle is about 45 deg. is provided at the mount part of the column 1 being the upper surface of the sample chamber and fixed on the upper end of the lens 2. By fixing the lower end of the lens 2 on the sample chamber 5 in such a way, the lens is supported at two points. In the case of plotting by stage continuous moving, a continuous moving direction is ordinarily fixed and reinforcement is performed to agree with the continuous moving direction so as to prevent rolling. By such structure, the supporting force of the column 1 does not depend on the strength of a sample chamber cover 4 but depends on the strength of the beam mounted in a stage moving direction. Especially, by reinforcing the beam 3 in the continuous moving direction to which importance is attached, in the case of continuous moving, the cover 4 is thinned and the entire device is made light in weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam drawing apparatus for exposing a fine pattern on a semiconductor or mask original plate, and
The present invention relates to an electron beam column holding device for improving the electron beam irradiation positioning accuracy.

[0002]

2. Description of the Related Art The prior art is a known example: (Jpn., J., Appl.,
Vol.32 (1993) pp6044-6048 Ota et al.), The lower part of the electron beam column is fixed to the lid of the sample chamber and the strength of the fixed part is optimized. The electron beam drawing apparatus has a history of development from the electron microscope, and the method of fixing the electron beam column has also been developed from the technology of the electron microscope.
The prior art shown in the publicly known example also aims to improve the rigidity of the electron beam column supported at one point by the fixed part, that is, the rigidity of the sample chamber lid. In essence, the weight is increased to improve the rigidity, and there are problems in maintainability and the like in addition to the improvement in characteristics. Especially in the stage continuous movement drawing, which is important as a high-speed drawing technique, the vibration of the electron beam column becomes a problem in terms of accuracy.

[0003]

A method of holding an electron beam column that prevents lateral vibration of the electron beam column due to external vibration or vibration inside the apparatus, especially movement of the sample stage, and enables highly accurate electron beam irradiation positioning. provide.

[0004]

An upper end of an objective lens of an electron beam column is fixed to a sample chamber by a beam. By fixing the lower end of the objective lens to the sample chamber, it supports at two points and prevents rolling.

[0005]

A beam of approximately 45 degrees is provided on the mounting portion of the electron beam column, which is the upper surface of the sample chamber, and the beam is fixed to the upper end of the objective lens.
Two points are supported by fixing the lower end of the objective lens to the sample chamber. In the case of stage continuous movement drawing, the continuous movement direction is usually fixed, and the reinforcement is aligned with that direction to prevent roll.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view of the present invention, and FIG. 2 is an explanatory view of a variable shaped electron beam drawing apparatus to which the present invention is applied. As shown in FIG. 2, the electron beam drawing apparatus generally reduces the electron source 1 or the shaped diaphragm image with a reduction lens, projects the image on the sample 14 with the objective lens 2, and generates a fine pattern according to the writing data. In the variable shaping type electron beam drawing apparatus, the first shaping diaphragm 7 is imaged on the second shaping diaphragm 10 by the shaping lens, and the transmission position thereof is controlled by the shaping deflector 8 to make the beam cross-sectional shape variable.

The beam deflector 13 of the objective lens 2 determines the irradiation position of the reduced electron beam. The sample stage 16 moves the sample 14 within the beam deflection range. The electron beam drawing apparatus sequentially moves the stage movement to the drawing position,
The so-called step-and-repeat drawing method and the continuous moving drawing in which the stage is moved continuously and the beam deflector 13 follows it are possible. In step-and-repeat drawing, the effect of mechanical vibration can be reduced by providing a settling time before drawing, but the drawing time increases. In continuous movement drawing, when the change in drawing density is small, there is an advantage that rapid acceleration / deceleration does not occur as in the step-and-repeat method. However, it can be said that it is mechanically always in a dynamic state, that is, in a vibrating state. Therefore, especially the rolling of the electron beam column in the continuous movement direction becomes a problem. FIG. 1 is an application example of the present invention.
In the analysis in the above-mentioned known example, it is concluded that the primary vibration mode is pendulum vibration of about 100 Hz with the fixed point of the sample chamber as the fulcrum, and reinforcement near the fulcrum is effective. In the embodiment, beams are passed to the upper and lower ends of the objective lens to support the column. In general, a reduction lens that reduces the beam by a few tenths is arranged above the objective lens, so that it is considered that vibration of the reduction lens or more is reduced by the same ratio. Therefore, economical and effective vibration isolation is possible by reinforcing only the objective lens. With this structure, the supporting force of the electron beam column does not depend on the strength of the sample chamber lid but on the strength of the beam mounted in the stage movement direction. In particular, in the case of continuous movement, if the beam in the continuous movement direction is strengthened, the sample chamber lid can be made thinner, and therefore the overall weight can be reduced. Although this embodiment is about fixing the electron beam column to the sample chamber, it is also applicable to mounting the sample chamber itself on a stand.

[0008]

The structure in which two points of the objective lens main body are supported by the beam in the sample chamber can effectively improve the support strength. Further, if the supporting direction is limited to the electron beam column in the stage moving direction, or the structure is strengthened, the sample chamber lid and the like can be lightened.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an electron beam drawing apparatus.

[Explanation of symbols]

1 ... Electron beam column, 2 ... Objective lens, 3 ... Fixed beam, 4 ...
Sample chamber lid, 5 ... Sample chamber.

Claims (2)

[Claims] 1. An electron gun for generating an electron beam, a shaped lens group for shaping the electron beam by a shaping diaphragm, a shaped lens group, a reduction lens group for reducing the shaped beam, and a reduced shaped beam for drawing a sample surface. An electron beam column consisting of an objective lens group for projecting onto a beam and a beam deflector for irradiating and positioning a projected image, a sample stage for moving a sample to a deflected irradiation position, and a sample chamber for holding the sample stage in vacuum. In the electron beam irradiation mechanism, an electron beam drawing apparatus characterized in that a lower part and an upper part of an objective lens are fixed to the sample chamber by beams. 2. An electron beam drawing apparatus reinforced according to claim 1, in a drawing system in which a stage is continuously moved and followed by the beam deflector in a continuous movement direction.