JPH05175107A - Charged particle beam lithographic method - Google Patents

Abstract

PURPOSE:To realize a method for charged particle beam lithography in which a quantity of data can be reduced even if it is approximated by many polygonal patterns by dividing a curved pattern. CONSTITUTION:If a curve pattern is divided, divided unit patterns are approximated by a polygonal shape, and a lithography of a desired curve pattern is effected based on data of the polygonal pattern, when the adjacent polygonal patterns are compared, upper and lower sides might be equal in vector directions. In such a case, the adjacent patterns are coupled, and data are compressed as a sole pattern. For example, when the vector directions of the sides of the divided polygonal patterns P1-P3 are checked, if the vector directions of the upper and lower sides of the curve to be lithographically drawn in the longitudinal direction coincide (theta11=theta21=theta31, theta12=theta22=theta32), the adjacent polygonal patterns are converted into single pattern data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam or ion beam drawing method, and more particularly to a charged particle beam drawing method most suitable for drawing a curved pattern.

[0002]

2. Description of the Related Art In an optical device or the like, a pattern through which light passes must be formed in a curved shape. When forming this curved pattern by electron beam drawing, electron beam drawing can only draw a pattern consisting of straight lines such as rectangles and trapezoids, so the electron beam drawing is performed after dividing the curved pattern into polygonal element patterns. There is a need to do. FIG. 4 shows a curved pattern P to be drawn.
When the data of this curved pattern is given, this pattern is divided by the reference length L, and the element pattern after division is approximated by a polygonal shape such as an elongated rectangle or trapezoid. FIG. 2 shows a state approximated by a polygonal shape. The electron beam drawing apparatus draws based on the large number of polygonal patterns.

[0003]

When the curved pattern is divided and approximated by a large number of polygonal patterns in this way, the amount of data increases dramatically, and it takes a long time to transfer the data or the data. The inconvenience arises in that the memory capacity for storing is increased.

The present invention has been made in view of such a point, and an object thereof is to relatively reduce the data amount even if a curved pattern is divided and approximated by a large number of polygonal patterns. It is to realize a charged particle beam drawing method that can be performed.

[0005]

A charged particle beam drawing method according to the present invention divides a curved pattern, approximates each divided unit pattern with a polygonal shape, and outputs a desired pattern based on the data of the polygonal pattern. In the charged particle beam drawing method adapted to draw a curved pattern, of the divided polygonal patterns, the vector direction of the side of the adjacent pattern is checked, and the upper and lower sides in the length direction of the curve to be drawn are checked. If the vector directions match, the adjacent polygonal patterns are converted into a single pattern data.

[0006]

In the charged particle beam drawing method according to the present invention, the vector directions of the sides of adjacent patterns among the divided polygonal patterns are checked, and the vector directions of the upper and lower sides of the length direction of the curve to be drawn are determined. If they match each other, the adjacent polygonal patterns are converted into a single pattern data. Normally, even if it is a curve pattern, the curvature of the curve changes subtly, and when a polygonal shape is approximated in a certain part, the vector directions of the upper and lower sides are the same when comparing adjacent polygonal patterns. There are cases. In such a case, adjacent patterns are concatenated and data is compressed as a single pattern.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 shows an example of an electron beam writing system for carrying out the present invention. Reference numeral 1 is a computer, 2 is a data memory, and the pattern data including the curve pattern data stored in the data memory 2 is read by the computer 1 and supplied to the division unit 3. The pattern data divided by the dividing unit 3 is supplied from the pattern data output unit 4 to the trapezoidal height processing unit 5, the first angle comparison unit 6, and the second angle comparison unit 7. The outputs of the first and second angle comparison units 6 and 7 are supplied to the comparison flag AND unit 8 and the pattern data storage unit 9. The output of the comparison flag AND unit 8 is supplied to the trapezoidal height processing unit 5. Reference numeral 10 is a height adding unit connected to the trapezoidal height processing unit 5. The output of the trapezoidal height processing unit 5 is supplied to the pattern data storage unit 9. The pattern data stored in the pattern data storage unit 9 is supplied to the exposure control unit 11, which produces a deflection signal necessary for writing, and the deflection signal of the electron beam writing apparatus 12 receives the deflection signal. Supplied. The operation of such a configuration will be described below.

First, the pattern data including the curve pattern stored in the data memory 2 is read by the computer 1 and supplied to the division unit 3. In the division unit 3, the curve pattern is divided by the reference length L, for example, as described in FIGS. 4 and 2, and the curve pattern after division is approximated to a polygonal shape. FIG. 1 shows three unit patterns P1 to P3 which are divided and approximated to a polygonal shape.
Data compression is described with reference to FIG. 4 as an example. First, when the drawing data of the unit pattern P1 is supplied from the division unit 3 to the data output unit 4, the data output unit 4 selects one of the trapezoidal data of the unit pattern P1.
The height data d1 is supplied to the trapezoidal height processing unit 5.
Further, the data output unit 4 supplies the trapezoidal angle data θ11, θ12 of the unit pattern P1 to the first angle comparison unit 6 and the second angle comparison unit 7, respectively. The height data d1 and the angle data .theta.11 and .theta.12 are temporarily stored in the memories in the units 5, 6, and 7 as initial data.

Next, the height data d2 and the angle data .theta.21 and .theta.22 of the drawing data of the unit pattern P2 adjacent to the unit pattern P1 are transferred from the data output unit 4 to the trapezoid processing unit 5, the first and second angle comparison units. 6 and 7 are supplied. In the first angle comparison unit 6, the unit pattern P
Angle data θ11 of 1 and angle data θ of unit pattern P2
21 and, in the second angle comparison unit 7,
Angle data θ12 of unit pattern P1 and unit pattern P2
The angle data θ22 of is compared. The result of this comparison is supplied to the comparison flag AND unit 8. Now, θ11 = θ2
When 1, θ21 = θ22, that is, when the vector directions of the upper side and the lower side of the trapezoidal patterns P1 and P2 are the same, the comparison flag AND unit 8 sends a status flag to the trapezoidal height processing unit 5. Based on this flag, the trapezoidal height processing unit 5 sends the trapezoidal height d1 of the unit pattern P1 and the trapezoidal height d2 of the unit pattern P2 to the height adding unit 10, adds d1 + d2, and adds the result dt1. It is stored again in the memory in the height processing unit 5.

Next, the height data d3 and the angle data θ31, θ32 of the drawing data of the unit pattern P3 adjacent to the unit pattern P2 are transferred from the data output unit 4 to the trapezoid processing unit 5, the first and second angle comparison units. 6 and 7 are supplied. In the first angle comparison unit 6, the unit pattern P
Angle data θ11 of 1 and angle data θ of unit pattern P3
31 and, in the second angle comparison unit 7,
Angle data θ12 of unit pattern P1 and unit pattern P3
The angle data θ32 of is compared. The result of this comparison is supplied to the comparison flag AND unit 8. Now, θ11 = θ3
When 1, θ12 = θ32, that is, the trapezoidal pattern P1
When the vector directions of the upper side and the lower side of (P2) and P3 are the same, the comparison flag AND unit 8 sends a status flag to the trapezoidal height processing unit 5. The trapezoidal height processing unit 5 sends the trapezoidal height dt1 added based on this flag and the height d3 of the unit pattern P3 to the height adding unit 10 to add dt1 + d3, and the addition result d
The t2 is again stored in the memory in the height processing unit 5.

Next, although not shown, the unit pattern P
The height data d4 and the angle data .theta.41 and .theta.42 of the drawing data of the unit pattern P4 adjacent to 3 are supplied from the data output unit 4 to the trapezoid processing unit 5, the first and second angle comparison units 6 and 7. The first angle comparison unit 6 compares the angle data θ11 of the unit pattern P1 with the angle data θ41 of the unit pattern P4, and the second angle comparison unit 7 compares the angle data θ12 of the unit pattern P1.
And the angle data θ42 of the unit pattern P4 are compared. The result of this comparison is supplied to the comparison flag AND unit 8. If any one of θ11 and θ41 and θ12 and θ42 is not equal, the comparison flag AND unit 8 sends the status flag to the trapezoidal height processing unit 5. as a result,
The trapezoidal height processing unit 5 sends the trapezoidal height dt2 added up to that time to the pattern data storage unit 9. And
The reference angles θ11 and θ12 stored in the angle comparison units 6 and 7 are sent to the pattern data storage unit 9 at the same time as the trapezoidal height. As a result, the pattern data storage unit 9 stores a new single trapezoidal pattern in which the three unit patterns P1 to P3 are combined. The stored new single pattern data is composed of the trapezoidal height and the angles of the two sides, and is obtained by compressing the three unit pattern data. The pattern data stored in the unit 9 is supplied to the exposure control unit 9, and the exposure control unit 11 creates a deflection signal necessary for drawing. This deflection signal is supplied to the deflector of the electron beam drawing apparatus 12, and a curved pattern approximated by a large number of polygonal patterns is drawn on the drawing material in the drawing apparatus 12.

Although the three unit patterns P1 to P3 are compressed into a single pattern data in the above-described embodiment, either of the angles .theta.21 and .theta.22 of the two sides of the unit pattern P2 corresponds to the unit pattern P1. When the angles are different from the angles θ11 and θ12, the data of the unit pattern P1 is sent to the pattern data storage unit without being compressed. The reference data stored in the trapezoidal height processing unit 5, the angle comparison units 6 and 7 can be changed to that of the unit pattern P2.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, the present invention can be applied to not only an electron beam drawing apparatus but also an ion beam drawing apparatus. Also, an example in which three pattern data are compressed into a single data has been described, but if the angles of the trapezoids are equal, even if there are two or three or more, they are compressed into a single pattern. be able to.

[0014]

As described above, in the charged particle beam drawing method according to the present invention, the vector direction of the side of the adjacent pattern among the divided polygonal patterns is checked, and the length of the curve to be drawn is determined. If the vector directions of the upper and lower sides of the direction are the same, the adjacent polygonal patterns are converted into single pattern data. Even if the pattern is approximated, the amount of data can be made relatively small.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment in the case of compressing data of three unit patterns.

FIG. 2 is a diagram showing a curved pattern divided by a large number of polygonal patterns.

FIG. 3 is a configuration diagram showing an example of an electron beam writing system for carrying out the method of the present invention.

FIG. 4 is a diagram showing a curved pattern to be drawn.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Computer 2 ... Data memory 3 ... Division unit 4 ... Pattern data output unit 5 ... Trapezoidal height processing unit 6, 7 ... Angle comparison unit 8 ... Comparison flag AND unit 9 ... Pattern data storage unit 10 ... Height addition unit 11 ... exposure control unit 12 ... electron beam drawing device

Claims (1)

[Claims] 1. A charged particle beam drawing method in which a curve pattern is divided, each unit pattern after the division is approximated by a polygonal shape, and a desired curve pattern is drawn based on the data of the polygonal pattern. , Of the divided polygonal patterns, check the vector directions of the sides of the adjacent patterns, and if the vector directions of the upper and lower sides of the length direction of the curve to be drawn match,
A charged particle beam drawing method, characterized in that the adjacent polygonal patterns are converted into a single pattern data.