JPH03116817A - Charged particle beam lithography device - Google Patents

Abstract

PURPOSE:To contrive improvement in accuracy of lithography position by a method wherein, among the data for main deflection, the date less than the minimum decomposition value of a main deflection DA converter is added to auxiliary deflection data, and the added value is rounded off on the side of the auxiliary deflection. CONSTITUTION:The data for main deflection, which is distortion-corrected by a main deflection distortion correcting arithmetic circuit 6, is sent to a data isolation circuit 16. The distortion- corrected main deflection data are separated by the minimum decomposition value of a main deflection DA converter 9 as the boundary, the data higher than the minimum decomposition data is sent to the main deflection DA converter 9, and the data on the terminal of the minimum decomposition value is sent to an adding circuit 17. Subsequently, the data for auxiliary deflection, the deflection of which is corrected by an auxiliary deflection distortion correcting arithmetic circuit 11, are sent to an adding circuit 17. At this point, the data less than the minimum decomposition value and the distortion-corrected auxiliary deflection data are added, and they are sent to a round-off processing circuit 13. The data less than the minimum decomposition value of an auxiliary deflection DA converter 14 are rounded to the nearest whole number by the round-off processing circuit 13, and they are sent to an adding circuit 10. Consequently, as final pattern position data supplied to a positional deflector 3 becomes the data containing only the error generated by one round-off processing, the accuracy of data patterning position can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a charged beam lithography apparatus that reduces malmo processing errors.

[Prior Art] Charged beam lithography systems have recently been in the spotlight as a means of manufacturing LSI devices and VLSI devices.

Figure 2 is a schematic diagram of an electron beam lithography system shown as an example of a charged beam lithography system. However, for convenience, it is expressed as one), 4
is a material placed on a stage (not shown).

With such a device, for example, each pattern P-, , P, , P3 + P4 in each sub-field SF+, SF2, SF, within field F as shown in FIG.
* When drawing P5 (in reality, usually many patterns are drawn in each subfield), draw as follows. The field F is large enough to draw a pattern with the scanning length of the beam (for example, 2.5 mm x 2.5 mm).
5mm), and the subfield is, for example, 100
The area has a size of approximately μm×100 μm.

First, specific position data (Xo+, You) of subfield SF1 with respect to the position (origin) of field F is supplied from pattern data generator 5 to main deflection distortion correction calculation circuit 6 and main deflection distortion correction value table 7. The table stores in advance distortion correction values corresponding to various main deflection distortion values, and the specific position data (Xo+, You)
An appropriate distortion correction value is sent to the main deflection distortion correction calculation circuit 6 using as an address. The output of the circuit, that is, the main deflection position data subjected to distortion correction is rounded off to the nearest whole number by the Marmö processing circuit 8, and is supplied to the addition circuit 10. Subsequently, similarly, the pattern data generating device 5 generates a specific position (X
Data (X+1+YIυ
(consisting of data indicating a specific position of the pattern P1 and beam scanning width data, hereinafter referred to as pattern drawing position data) is supplied to the sub-deflection distortion correction calculation circuit 11 and the sub-deflection distortion correction value table 12. The table stores in advance distortion correction values corresponding to various sub-deflection distortion values,
Using the pattern drawing position data (X++, Yz) as an address, an appropriate distortion correction value is determined by the sub-deflection distortion correction calculation circuit 11.
sent to. The output of the circuit, that is, the sub-deflection position data subjected to distortion correction, is sent to the Marumo processing circuit 13 and sent to the sub-deflection DA.
Addition circuit 1 rounds off values less than the minimum resolution value of converter 14
Supply to 0. The data added by the adding circuit 10 is
The signal is sent to the positioning deflector 3 via the amplifier 15. Since the beam scans the pattern area from a specific position within the pattern area, the pattern P1 is drawn.

In the above example, the Marmo processing circuit operates to round off values less than the minimum decomposition value of the DA converter, but it may also be configured to round up or down. This kind of rounding, rounding up, or rounding down of data is called round processing.

Thereafter, in the same manner, the specific position data of each subfield is sent from the pattern data generator to the main deflection distortion correction calculation circuit 6 and the main deflection distortion correction value table 7 in order to draw each pattern for the specific position of each subfield. Pattern drawing position data indicating the position of the beam is supplied to the sub-deflection distortion correction calculation circuit 11 and the sub-deflection distortion correction value table 12, and all patterns are drawn.

Now, when drawing a pattern in such a drawing apparatus, as described above, the position of the pattern is represented by a specific position of the sub-yield and a relative position to the specific position, and a dedicated main deflection DA converter 9 is used for each. , sub-deflection DA converter 14
is man-powered. In this case, a high-precision DA converter with high bits (for example, 14 to 16 bits) is used as the DA converter for main deflection, and a DA converter with lower bits (for example, By using a high-speed DA converter (9 to 12 bits), high-speed and high-precision pattern drawing is possible (Japanese Patent Publication No. 11830/1983).
(See Special Publication No. 53-24792). As described above, the specific position data of the subfields, that is, the data for main deflection, and the pattern drawing position data, that is, the data for sub-deflection, are each subjected to the Marume processing. This Marume process is carried out by each DA.
This is done because there is a minimum value that can be decomposed since there is a limit to the bit length of the converter, and the bits less than the minimum decomposable bit of each DA converter are processed.

[Problem to be solved by the invention] However, since the main deflection data and the sub-deflection data are processed separately in this way, the final data supplied to the positioning deflector 3 is The pattern position data is data obtained by adding errors (Marumé errors) generated by each Marumé process.

Therefore, there is a problem in improving the drawing position accuracy.

The present invention is aimed at solving such problems.

[Means for Solving the Problems] Therefore, the charged beam writing apparatus of the present invention includes a charged beam generating means, a lens for focusing the beam from the means onto a material, subfield specific position data, and a pattern writing position. A pattern data generator that generates data, a main deflection distortion correction calculation circuit that performs deflection distortion correction on the subfield specific position data, and a minimum resolution value of the main deflection DA converter that converts the output data of the main deflection distortion correction calculation circuit into a separation circuit that separates data at the border and sends data equal to or greater than the minimum resolution value to the main deflection DA converter; a sub-deflection distortion correction calculation circuit that performs deflection distortion correction on the pattern drawing position data; and the sub-deflection distortion correction calculation circuit. an adder circuit for adding the output data of and data smaller than the minimum decomposition value from the separation circuit; a Malmö processing circuit for performing Malmö processing of the output data of the adder circuit; and a Malmö processing circuit for converting the output of the Malmö processing circuit into an analog value. A deflector for scanning a material with a beam based on the output of the main deflection DA converter and the output of the sub deflection DA converter was provided.

[Embodiment] FIG. 1 is a schematic diagram of an electron beam lithography apparatus showing an embodiment of the present invention. In the figure, the numbers used in FIG. 2 are the same components.

In the figure, 16 is a data separation circuit, and 17 is an addition circuit.

With such a device, for example, each pattern p, p2 . p3 + P4 +
When drawing P5, draw it as follows.

First, specific position data (X o I, Y o 1) of subfield SF1 with respect to the position (origin) of field F is supplied from pattern data generator 5 to main deflection distortion correction calculation circuit 6 and main deflection distortion correction value table 7. be done. The table sends appropriate distortion correction values for the specific position data (X.In Yot) to the main deflection distortion correction calculation circuit 6.

The output of the main deflection distortion correction calculation circuit 6, that is, the main deflection data subjected to distortion correction, is sent to the data separation circuit 16.

The data separation circuit separates the main deflection data subjected to the distortion correction using the minimum resolution value of the main deflection DA converter 9 as a boundary,
Data greater than or equal to the minimum decomposition value is sent to the main deflection DA converter 9, and data less than the minimum decomposition value is sent to the addition circuit 17.

Subsequently, in the same way, the specific position (X or , Y
Data (X++, Y++) indicating the position of the beam for drawing the pattern P1 with respect to o1) is supplied to the sub-deflection distortion correction calculation circuit 11 and the sub-deflection distortion correction value table 12. The table sends a distortion correction value corresponding to the sub-deflection distortion value to the sub-deflection distortion correction calculation circuit 11. The output of the circuit, that is, the distortion-corrected sub-deflection data is sent to the adder circuit 1.
Sent to 7. The adding circuit adds the data less than the minimum resolution value and the distortion-corrected sub-deflection data, and sends the result to the Marmö processing circuit 13. The Marumo processing circuit 13 rounds off data less than the minimum decomposition value of the sub-deflection DA converter 14 and supplies the rounded data to the addition circuit 10 . The adder circuit 10 connects the output of the Malmö processing circuit 13 and the main deflection DA converter 9.
The outputs of are added and sent to the positioning deflector 3 via the amplifier 15.

Since the beam scans the pattern area from a specific position within the pattern area, the pattern P1 is drawn.

Thereafter, all patterns are drawn by repeating the same series of operations.

Incidentally, in the above embodiment, the mulme treatment on the main deflection side is eliminated,
I'm trying to process it in a sub-biased example sentence. Conversely, it is possible to eliminate the Malmö processing on the sub-deflection side and use the main deflection example sentence, but when the main deflection operates once, the sub-deflection usually operates many times, so it is better to perform the latter Malmö processing. is not a good idea in terms of operation.

Further, the present invention can also be applied to a lithography apparatus such as an ion beam lithography apparatus.

[Effects of the Invention] In the present invention, among the main deflection data, data that is less than the minimum resolution value of the main deflection DA converter is added to the sub deflection data, and the added data is processed by the sub deflection side. Because there is
The final pattern position data supplied to the positioning deflector includes the error (Malmö error) generated by one Malmö process. Therefore, compared to conventional final pattern position data that includes errors due to the Marumé processing on the main deflection side and errors due to the Marumé processing on the sub-deflection side, the error due to the Marumé processing is smaller. Therefore, data drawing position accuracy has been further improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an electron beam lithography system shown as an embodiment of the present invention, FIG. 2 is a schematic diagram of an electron beam lithography system shown as a conventional example, and FIG. 3 shows subfields in field F. This represents the positional relationship of each pattern within each subfield. 1: Electron gun 2: Focusing lens 3: Deflector for positioning 4: Material 5: Pattern data generator 6
: Main deflection distortion correction calculation circuit 7 Main deflection distortion correction value table 8: Malta processing circuit 9: Main deflection DA converter 1
0 addition circuit 11: Sub-deflection distortion correction calculation circuit 12: Sub-deflection distortion correction value dople 13: Malmo processing circuit 14: Sub-deflection DA converter 15: Amplifier 16: Data separation circuit 17: Addition circuit

Claims (1)

[Claims] A charged beam generating means, a lens for focusing the beam from the means onto a material, a pattern data generating device for generating subfield specific position data and pattern drawing position data, and applying deflection distortion correction to the subfield specific position data. The main deflection distortion correction calculation circuit separates the output data of the main deflection distortion correction calculation circuit at the minimum resolution value of the main deflection DA converter, and the data exceeding the minimum resolution value is transferred to the main deflection DA converter.
a separation circuit to be sent to a converter; a sub-deflection distortion correction calculation circuit that performs deflection distortion correction on the pattern drawing position data; and adding the output data of the sub-deflection distortion correction calculation circuit and data smaller than the minimum resolution value from the separation circuit. an adder circuit for processing the output data of the adder circuit, a Malmö processing circuit for performing Malmö processing of the output data of the adder circuit, a sub-deflection DA converter for converting the output of the Malmö processing circuit into an analog value, an output of the main deflection DA converter; A charged beam drawing device equipped with a deflector that scans a beam over a material based on the output of a sub-deflection DA converter.