JP2577966B2 - Charged beam drawing method and apparatus - Google Patents

Description

Description: Object of the Invention (Industrial Application Field) The present invention relates to a method and an apparatus for drawing a pattern by using a charged beam, and particularly includes an element pattern having a similar relationship in a pattern to be drawn. The present invention relates to a pattern drawing method and apparatus.

(Prior Art) When drawing a pattern with a charged beam, a pattern to be drawn is generally converted into data in a predetermined format suitable for a drawing apparatus using CAD. This is referred to as pattern data, and this pattern data is enormous when the pattern to be drawn is complicated.

(Problem to be Solved by the Invention) When the amount of pattern data is large, not only the time and cost required to create the pattern data increase, but also a large memory such as a magnetic disk for storing the data is required. In this case, there is a problem that the drawing must be interrupted due to the relationship between the input time from the dispersed magnetic disk and the drawing time as the cost increases in this aspect. .

An object of the present invention is to provide a writing method for reducing the amount of pattern data necessary for charged beam writing and a charged beam writing apparatus suitable for carrying out the writing method.

[Configuration of the invention]

(Means for Solving the Problems) A charged beam drawing method according to the present invention for achieving the above object provides at least one element pattern selected from each element pattern having a similar relationship included in a pattern to be drawn. Using the pattern data and array data having a similarity ratio with respect to the array position of each element pattern and each of the element patterns converted into the pattern data of each element pattern, the pattern data of the writing apparatus is used in accordance with the similarity ratio. By changing the scaling ratio, each element pattern is drawn to complete drawing of all patterns.

One of the patterns suitable for carrying out this method is a pattern in which element patterns having a similar relationship are multiplexed and arranged on a concentric circle. In such a case, each element pattern multiplexed is arranged. Pattern data may be created and used individually or collectively for a plurality of spaced element patterns among the patterns.

Also, the charged beam drawing apparatus according to the present invention naturally has a scaling function,
Further, there is provided means for correcting the displacement of the charged beam in accordance with the scaling ratio.

(Operation) For example, one element pattern is selected from each of the element patterns having a similar relationship and converted into data, and the other element patterns are drawn using a scaling function. Therefore,
The amount of pattern data required for drawing is compressed. It is necessary to devise how to capture the similarity depending on the pattern, and this devise makes it possible to draw a pattern which conventionally required a huge amount of pattern data and was considered practically impossible.

In addition, the displacement of the charged beam may be caused by the scaling, but this is solved by correcting the displacement according to the scaling ratio, and the drawing accuracy can be maintained.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows an example of a pattern to be drawn by applying the present invention. This pattern 10 has a checkered pattern divided into a large number in a circumferential direction and a large number in a radial direction. In FIG. 1, the number of divisions is reduced in view of the expression. However, in actuality, it is finely divided with a width of several μm to several tens of μm. When converted to pattern data, the amount of data becomes enormous.

However, the pattern data 10 is a so-called element pattern 10a (FIG. 2) in which the outermost unit ring pattern 11 including the unit pattern 11a and the second unit ring pattern 12 from the outside including the unit pattern 12a are combined. Can be seen as being multiplexed while being sequentially reduced toward the center of the pattern 10.

That is, the second and third unit ring-shaped patterns 13, 14 from the outside and the element pattern 10a are formed.
The two unit ring-shaped patterns 11, 12 have a similar relationship,
Further, each inner unit ring-shaped pattern also has a similar relationship to the element pattern 10a in a combination of two.

Therefore, the present invention does not create pattern data for the entire pattern 10 shown in FIG. 1, but creates only the element pattern 10a shown in FIG. This element pattern 10a
The pattern data amount of the pattern 10 is reduced to the amount obtained by dividing the total pattern data amount of the pattern 10 by the number of each element pattern having a similar relationship included in the pattern 10, and the pattern data of FIG.
When 10 is finely divided as described above, the pattern data amount is greatly reduced.

The pattern data of the element pattern 10a is stored in a memory 21 such as a magnetic disk of the charged beam drawing apparatus shown in FIG. The memory 21 stores, together with the pattern data, the position information of the element pattern 10a and each of the element patterns sequentially located inside in FIG. 1 having a similar relation to the element pattern 10a and the similarity ratio (reduction or enlargement ratio) to the element pattern 10a, The array data with the scaling ratio is stored. The scaling ratio may be input from a keyboard (not shown) for each drawing of each element pattern.

Thus, the element pattern 10 by the pattern data
Since the scaling ratio of a is 1, the unit ring patterns 11 and 12 in FIG. 1 are drawn by a known method using a charged beam drawing apparatus as shown in FIG.

In FIG. 3, 23 is an interface, 24 is a blanking circuit, 25 is a scanning circuit, 26 is a laser length meter for measuring the position of the XY stage 39, 27 is a stage drive system, and 30 is a charged beam optical mirror. A cylinder, 31 is its power source, 32 is a beam generator, 33 is a charged beam, 34 to 36 are electron lenses, 37 is a blanking electrode, 38 is a scanning electrode, and 1 is a sample for drawing the pattern 10 shown in FIG. It is.

After the outer two unit ring patterns 11 and 12 shown in FIG. 1 are thus drawn, the two inner ring patterns 13 and 14 located inside are drawn next. Since the reduction ratio of the patterns 13 and 14 with respect to 11, 12 is calculated in advance as the scaling ratio and stored in the magnetic disk 21, it is read out by the computer 22 or when not stored in the magnetic disk 21 Input from the keyboard, each parameter of the drawing unit necessary for changing the scaling ratio, that is, the thickness of the charged beam 33,
And current value, scan width, scan interval and XY stage 39
Is changed in accordance with the scaling rate.

Since the displacement of the charged beam 33 is caused by the change in the scaling ratio, a signal at the time of voltage for correcting the displacement according to the scaling ratio is given to the scanning circuit 25 by a command from the computer 22. ing.

When the change of the scaling ratio is completed, drawing is performed based on the pattern data of the element pattern 10a and the position information of the element pattern including the unit ring patterns 13 and 14 shown in FIG. With this drawing, the unit ring patterns 13 and 14 shown in FIG. 1 are drawn.

Hereinafter, also for the unit ring-shaped pattern inside sequentially,
By drawing while changing the scaling ratio, a checkerboard ring-shaped pattern 10 shown in FIG. 1 is drawn.

In the above-described embodiment, the example in which the element pattern 10a is sequentially reduced and drawn is shown. However, since there is generally a limit on the scaleable reduction and enlargement ranges, the element patterns for creating the pattern data are the respective element patterns to be drawn. In some cases, it may be necessary to select an intermediate medium size, or to select a plurality of intermediate sizes. In the case of converting a plurality of element patterns having different sizes into data, as shown in FIG. 1, when the arrangement relation of the element patterns is constant, they are grouped as a set of element patterns. By converting the data into data, the number of drawing times can be reduced.

In addition, as shown in FIG. 1, when the element patterns are connected to each other, errors are accumulated by overlapping the scaling, so that the scaling may be performed in several steps by dividing at appropriate places. If scaling is performed in several steps, the present invention can be applied to patterns that are not completely similar to each other as a whole.

Furthermore, it goes without saying that the present invention can also be applied to a pattern in which each element pattern is randomly arranged on XY coordinates.

〔The invention's effect〕

As described above, according to the charged beam drawing method of the present invention, a pattern having a similar relationship can be drawn with less pattern data, and a large number of element patterns of the same shape having different sizes are collected. It is very effective in drawing patterns.

Further, according to the drawing apparatus of the present invention, since the positional deviation of the charged beam is corrected according to the scaling ratio, it is possible to prevent a decrease in drawing accuracy due to overlapping scaling,
The drawing method according to the present invention can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a pattern to be drawn according to the present invention, FIG. 2 is a plan view showing one element pattern for creating pattern data by selecting from the patterns of FIG. 1,
FIG. 3 is a conceptual diagram showing an example of a charged beam drawing apparatus for carrying out the present invention. 1 ... sample, 10 ... pattern, 10a ... element pattern, 11-14 ... unit ring pattern, 21 ... memory (magnetic disk), 22 ... computer, 23 ...
Interface, 24 Blanking circuit, 25 Scanning circuit, 26 Laser measuring instrument, 27 Stage drive system, 30 Optical beam column, 32 Beam generating section, 33 Charge beam , 34-36 ... Electronic lens, 37 ... Blanking electrode, 38 ... Scanning electrode, 39 ... XY stage.

Claims (4)

(57) [Claims] At least one selected from each of element patterns having a similar relationship included in a pattern to be drawn.
Pattern data for drawing is created for one element pattern, and using the pattern data and array data having an array position of each of the element patterns and a similarity ratio of each of the element patterns to the element pattern converted into the pattern data, A charged beam writing method characterized by changing the scaling ratio of the writing apparatus in accordance with the ratio and writing each element pattern to complete writing of all patterns. 2. The charged beam drawing method according to claim 1, wherein each element pattern having a similar relationship is arranged in multiple concentric circles. 3. The charging device according to claim 2, wherein pattern data is created and used individually or collectively for a plurality of spaced element patterns among multiple element patterns arranged concentrically. Beam drawing method. 4. A charged beam drawing apparatus having a scaling function, wherein means for correcting a displacement of a charged beam in accordance with a scaling ratio is provided.