JPS6165428A - Drawing method of charged particle beam lithography equipment - Google Patents

Abstract

PURPOSE:To prevent the deterioration of drawing accuracy by a method wherein the table speed is made constant regardless of the pattern density in the titled equipment of table-coupled transfer type. CONSTITUTION:The deflection width of a beam 1 is controlled according to the pattern density by constantly controlling the speed of reciprocating transfer of the table 2 in the X or Y direction. In other words, the pattern density of drawing data is calculated by a pattern density calculating circuit 6, and the deflection width corresponding to the pattern density is calculated by a frame width calculating circuit 7. A drawing position calculating circuit 8 controls beam deflection systems 10-13 on the basis of a table position circuit 9, the frame width calculating circuit 7, and the drawing data, then controlling the deflection width of the beam 1 narrowly in a place of large pattern density and widely in that of small density. This enables the table speed to be kept constant regardless of the pattern density; therefore, the improvement in drawing accuracy can be contrived. Besides, the drive control of the table can be easily performed.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a lithography method for a charged particle beam lithography device, such as an electron beam exposure device. [Technical Background and Problems of the Invention] A continuously moving table scattering electron beam fogging device Then, drawing is performed by irradiating a rectangular electron beam while moving the table back and forth. If the table speed for reciprocating the table is faster than the drawing speed (speed determined by the pattern drawing density), some patterns cannot be drawn. For this reason, the table speed is controlled by reducing the table speed where the pattern density is high so that the pattern is not completely drawn. However, it is difficult to control the table speed at high speed, and locations with high pattern density must be predicted in advance from positions where the table speed can be controlled.

Furthermore, changing the table speed makes the circuit for controlling drawing complicated. In other words, if the table speed is kept constant, the effect on the drawing pattern due to the delay time of the drawing control circuit is only a slight movement in the Y (or X) direction, but if the table speed is made variable, the effect on the drawing pattern is This results in a mottled pattern and deteriorates the accuracy of drawing.

[Purpose of the invention]

The purpose of the present invention is to make the table speed independent of pattern density (
1. l! This is to prevent deterioration of the lj concubine.

[Summary of the invention]

The present invention uses a rectangular charged particle beam while reciprocating the table? The irradiating table is moved back and forth at a constant speed in a continuously moving charged particle beam lithography device, and the areas where the pattern density is high are the X1 horizontal width of the charged particle beam and the narrow comb.
Where the pattern density is low, writing is performed by varying the X deflection width of the charged particle beam and harmonizing the table speed and writing speed.

〔Effect of the invention〕

According to the present invention, by keeping the table speed constant, it becomes easier to correct the parallel lift in the y direction of the drawn pattern and to control the drive of the table.

[Embodiment 1 of the Invention] FIG. 1 shows an example of the configuration of a continuously moving table type' crawler beam exposure device.

In FIG. 1, the pattern density of the drawing data is calculated by a pattern density meter circuit 6. This corresponds to the calculation Vζ of the equi-edge area DE to be drawn described above. A frame width calculation circuit 7 calculates the deflection width r'. The drawing position calculation circuit 8 calculates the drawing position using the drawing data, (frame width) deflection 1f D7', and table position 9, and blanking circuit 10.
Beam forming circuit 11°X deflection circuit 12. The Y+ oblate inward direction circuit 13 is controlled to draw a rectangular doublet beam 1 and a pattern on the wafer 3 on the table 2.

- Figure 2 shows a continuous table movement type electron beam exposure method in which a table 2 is moved back and forth and a rectangular electron beam 1 is used to draw a wafer 3 placed on the table 2.

VT the speed at which table 2 is reciprocated Rectangular electron beam 1
If the drawing speed by irradiation is VD, and the deflectable width of the rectangular electron beam 1 is f+D7, then (Vr −”10
)t<Dy (0 relationship is 711IF
If you choose A, there will be no leftover drawings. However, t is the drawing time. Equivalent area to be drawn (LSI patterns are not necessarily clustered together, but small patterns are dispersed.

Isometrically, one side of this dispersed pattern is the deflection width D□
Let the area considered as the rectangular pattern be the equivalent area l Dg
The time t for drawing is rearranged by substituting ■ into ■.

If so, the table speed vT is 3 of the drawing speed vD.
You can double the speed. If the equivalent area Dg to be drawn is O, vT is ω, and if DE=D, My == 2
VI). However, ■ holds true in the range <D.

The drawing speed VD increases as the deflection width D1 becomes narrower.

The drawing speed vD' when the deflection width is D is now the drawing speed vD' if the deflection width D and 7 are set to ID.
is twice the drawing speed VD when the deflection width is DJ.

The equivalent area to be drawn is D E + drawing speed vDr deflection 1
@(Y direction ID If the table speed at D, is vT, then Lr=(1+”lyD ■ 1)E When the equi-edge area to be drawn becomes DE', ■Equation tl-is satisfied (i.e. from DE 1M drawing speed where the table speed does not change even when DE' is reached) If the drawing speed is V.', then vT = (t + gradient vD') ■ Substituting the formula 0 into the formula ■, we get the formula 9 and ■ From the formula, vT + ``D is Urayasu, and the relationship between :' and D is as follows.

For example, if you are writing at a table speed determined by the deflection @D = D = 1000 μm and the equivalent area to be written DB = 2511/1 m, the density of the pattern to be drawn becomes dense and D6
= sooμm, then the deflection interval D is 600μ
If the width is narrowed to DE=25f)μm, writing can be performed at the same table speed as when writing with DE=25f)μm. FIG. 3 shows the relationship between the pattern density to be written and the deflection i corner D□.

When drawing a 3-inch LSI pattern on a wafer, the deflection width D
Divide and draw the width of the image. The woofer 3 divided into deflection and [D] parts is called frame 4.

The fortune in frame 4 does not change within the frame.

When the pattern density is small, the frame width is widened, and when the pattern density is large, the frame width is f! r: Narrow.

Determine the deflection width D□ from the maximum or minimum of the drawing pattern 50 equivalent area DE in the frame.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a continuously moving table type electron beam exposure apparatus. FIG. 2 is a diagram for explaining the principle of a continuously moving table type electron beam exposure apparatus. FIG. 3 is an explanatory diagram showing the relationship between butter 7 density and deflection @ (frame width). 1... Rectangular electron beam. 2... table. 3...Wafer. 4...Frame 1 5...Drawing pattern. 6...Pattern density calculation circuit. 7...Frame I fortune calculation circuit. 8...Drawing position calculation circuit. 9...Table position circuit. 10... Gra/King circuit. 11... Beam forming circuit. 12...X deflection circuit. 13...Y1 Nannan circuit. (73171 Patent Attorney Nori Wakasuke Chika (and 1 other person) Figure 1

Claims (1)

[Claims] A sample placed on a table that can be moved in the X and Y directions is moved a minute amount in the X or Y direction each time the table moves back and forth in the Y or X direction, and the sample is irradiated with a rectangular or triangular charged particle beam. In a charged particle beam drawing device that draws a pattern, the speed of the table is kept almost constant in the Y or X direction, and if the density of the pattern to be drawn is large, the deflection width in the A lithography method using a charged particle beam lithography apparatus, which is characterized in that when .