JP3341547B2 - Electron beam drawing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam lithography apparatus, and more particularly, to an electron beam lithography apparatus for performing writing by moving a stage continuously.

[0002]

2. Description of the Related Art Conventionally, in the step-and-repeat type writing, writing on a sample is not performed when a stage is moved. Therefore, the time between the stages is a waste time, which is an obstacle to shortening the writing time (improving throughput). I have. On the other hand, in drawing by continuous movement of the stage, simultaneous drawing is performed while moving the stage, so that the dead time associated with the movement of the stage is eliminated and the drawing time can be reduced. As a method of continuously moving the stage, there is a variable speed movement in which the moving speed of the stage is changed depending on the uniform speed movement and the density of the drawing pattern.

[0003]

In the prior art drawing by continuous movement of the stage, the width which can be drawn during the movement of the stage (column stripe width), that is, the range which can be drawn by deflecting the electron beam in a direction perpendicular to the movement of the stage. Is limited to a maximum of about 5 mm in consideration of drawing accuracy. Here, the smaller the column stripe width is, the more the accuracy is improved to some extent, but the number of divisions of the drawing pattern into column stripes is increased, and the number of continuous movements of the stage is increased accordingly. This will increase the time (reduce the throughput).

As one of the measures for improving the drawing accuracy, so-called multiple drawing has been considered (Japanese Patent Laid-Open No. 6-36995).
However, there is a problem in throughput because it has nothing to do with continuous drawing.

An object of the present invention is to provide an electron beam lithography apparatus suitable for improving the lithography accuracy without lowering the throughput.

[0006]

An electron beam lithography apparatus according to the present invention comprises a stage for moving a sample, an electron gun for irradiating the sample with an electron beam, and a step for dividing the sample into stripes.
And control means for controlling the irradiation time of the sample by the electron beam with split and by deflecting the electron beam in relation to the movement of the sample in each stripe for drawing positioning with respect to the sample of the electron beam Deflects the electron beam
To divide the stripe into a plurality of sub-deflection areas.
The director and the sub deflection area are further divided into a plurality of sub sub deflection areas.
And a sub deflector for split, while continuously the moving the sample, multiple writing lines UTO for each drawing point
In both cases, each writing in the multiple writing is performed by a method of deflecting the electron beam.
Each deflector in a direction perpendicular to the direction of said movement.
Of the sub-deflection area.
Deflection direction of the main deflector with respect to the region and the sub-sub deflection region
Is opposite to the direction of deflection of the sub deflector with respect to
The electron beam is positioned at the same position with respect to each drawing, and the electron beam is irradiated in such a manner that the irradiation time for each drawing portion is in inverse proportion to the number of times of the multiple drawing.

According to this, even when the sample is divided into stripes and writing is performed by continuously moving the sample for each stripe, it is not necessary to reduce the width of the stripe to improve the writing accuracy. A drop in put is prevented. Further, due to the multiple writing, the influence of noise, drift and the like, which are error factors of the electron beam deflection control means, is reduced, and thus the writing accuracy is improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 shows an overall configuration diagram of an electron beam drawing apparatus. The stage 2 is housed in the apparatus main body 1. Sample 3 for drawing
Are mounted on the stage 2. The position of the stage 2 is measured by the length meter 4. The stage control unit 5 performs a moving operation of the stage 2 by controlling the driving unit 6 according to a command from the control computer 7.

The control computer 7 rearranges the drawing pattern data 8 for each column (stripe) in accordance with the drawing order on the sample, and transfers the data to the buffer memory 9. In the drawing control unit 10, when the drawing operation is started by the control computer 7, the drawing control unit 10
The drawing pattern data 8 is sequentially read out, the shot pattern is decomposed into shots, and the coordinates of each shot are calculated.
The data 10a is created and sent to the follow-up correction unit 11. The follow-up correction unit 11 derives deflection data 11a from the stage position 4a measured by the length measuring device 4 and the shot data 10a.
When the stage 2 enters the deflection range, the deflection controller 12 is activated. The deflection control unit 12 performs a writing operation of a writing pattern on the sample 3 mounted on the stage 2 by accurately deflecting the electron beam 14a emitted from the electron gun 14 in accordance with the deflection data 11a.
In the figure, reference numeral 13 denotes an A / D converter.

In the continuous movement drawing, the control computer 7 starts the drawing operation to the drawing control unit 10 for each column (stripe), and then starts the column (stripe) movement operation to the stage control unit 5. It takes.

FIG. 2 shows a drawing method in a column stripe. In the stripe, the drawing area is divided into two stages, a sub deflection area and a sub sub deflection area. Assuming that the stage moving direction in each stripe is Y and the direction perpendicular to the stage moving direction is X, the drawing area is sequentially updated in the X direction.
It is updated in the Y direction in synchronization with the stage movement. The sub deflection area is deflected by the main deflector in the deflection control unit 13. Each sub-deflection area in the sub-deflection area is deflected by a sub-deflector in the deflection control unit 13. Next, the positioning of the drawing data in the sub-sub deflection area, that is, the positioning of the drawing, is performed by the deflection by the sub-sub deflector in the deflection control unit 13.

FIG. 3 shows an example of a deflection operation in the X direction in each stripe. FIG. 3A shows an example of a deflection operation by the main deflector, and FIG. 3B shows an example of a deflection operation by the sub deflector. In the X direction, the deflection operations of the main deflector and the sub deflector are regularly repeated within the stripe. On the other hand, in the Y direction, when the drawing speed is almost the same as the stage moving speed, the operation area of the main deflector in the deflection control unit 13 is small. Thus, the decrease in the drawing accuracy due to the size of the deflection operation area is greater in the X direction.

FIG. 4 shows a flowchart for multiple drawing. First, the number N of multiple writings and the deflection offset ΔX
Is specified. Next, when the number of times n of the multiple writing is set to 1 and the writing of the stripe is started, the writing is repeated a plurality of times for each row of the sub-deflection area in the stripe in the X direction until n> N is satisfied. Will be Here, in the drawing for each column in each X direction, at the beginning of each repeated drawing, the offset Xmoff of the main deflector (input drawing data is “0”)
Is added only in the X direction by ΔX. Further, the offset Xsoff of the sub deflector is added by −ΔX only in the X direction. by this,
In each repetitive drawing, drawing positioning can be performed while changing the deflection operation area of each deflector and drawing the drawing data at the same position.

The above operation is repeated until the writing of the final sub-deflection region in the Y direction with one stripe is completed, and when the writing is completed, the writing is shifted to the stripe of the next column. In this case, the selection of the stripe is performed by the stage movement.

In the above, it is necessary to set the irradiation time of the electron beam in inverse proportion to the number of times of repetition of drawing (the number of times of multiple drawing).

FIG. 5 shows a deflection operation in multiple writing. 5A shows an operation example of the main deflector, and FIG. 5B shows a deflection operation example of the sub deflector. The deflection operation areas of the main deflector and the sub deflector are repeatedly drawn (multi-drawing) while moving by ΔX and −ΔX for each row of the sub deflection areas in the X direction in the stripe. That is, in FIG.
As shown in the figure, each writing in multiple writing
Direction is perpendicular to the direction of stage movement.
This is performed by changing the deflection operation area of
The deflection direction of the main deflector and the sub
Direction is opposite to the deflection direction of the
It is positioned and drawn. As a result, the averaging effect
Is obtained, and the drawing accuracy is improved.

In the above multiple writing, if the irradiation time of the electron beam in each row in the X direction is made unequal, it is possible to change the writing time in each row in the X direction, and to reduce the noise of a specific frequency. It is possible to improve the averaging (averaging) effect.

This can also be realized by making the drawing positioning time variable in each drawing in multiple writing.

In FIG. 2, (A), (B), (C),
(E) and (f) and a, b and c correspond to those in FIGS.

[0020]

According to the present invention, it is possible to improve the drawing accuracy without lowering the throughput.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electron beam lithography apparatus showing an embodiment based on the present invention.

FIG. 2 is a drawing explanatory diagram in a stripe.

FIG. 3 is an explanatory diagram of a deflection operation as an example by a main deflector and a sub deflector.

FIG. 4 is a diagram showing a flow chart of multiple drawing as an example based on the present invention.

FIG. 5 is an explanatory diagram of a deflection operation at the time of multiple writing as another example by the main deflector and the sub deflector.

[Explanation of symbols]

1: apparatus main body, 2: stage, 3: sample, 4: length measuring instrument,
4a: Stage position, 5: Stage control unit, 6: Drive unit, 7: Control computer, 8: Drawing pattern data, 9:
Buffer memory, 10: drawing control unit, 10a: shot data, 11: follow-up correction unit, 11a: deflection data,
12: deflection controller, 12a: deflection data, 13: electron source, 13a: electron beam.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/027

Claims (3)

(57) [Claims] 1. A and stage means for moving a sample, and an electron gun which irradiates an electron beam onto the sample, the sample stripe
Split control means for controlling the irradiation time to the sample in the electron beam performs drawing position by deflecting the electron beam in relation to the movement of the sample in each stripe
And deflecting the electron beam to form a plurality of stripes in the stripe.
The main deflector and the sub-deflection area are divided into sub-deflection areas.
And a sub-deflector into a plurality of sub-sub-deflection region, while continuously the moving the sample, performs a multiple writing for each drawing point, the drawing of said multiplexing Drawing
The image shows that the deflection direction of the electron beam is
The deflection operation area of each deflector is changed in the direction of the angle.
The deflection of the main deflector with respect to the sub-deflection area
Direction and direction of deflection of the sub-deflector with respect to the sub-sub-deflection area
Opposite to the direction, the same position for each drawing
The electron beam lithography apparatus is characterized in that the electron beam is radiated in such a manner that the irradiation time for each of the drawing portions is determined in inverse proportion to the number of times of the multiple drawing. 2. The electron beam lithography apparatus according to claim 1, wherein the irradiation time in each writing in the multiple writing is controlled so as to be non-uniform. 3. The electron beam lithography apparatus according to claim 1, wherein the time of the lithography positioning in each lithography in said multiple lithography is made variable.