JPH05234859A - Charged particle beam writing system - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a charged particle beam drawing apparatus that can perform drawing pattern scaling processing with high accuracy. [Structure] When the drawing pattern is scaled, the scaling coefficient is set in the register 12 from the CPU 1. As a result, the output of the multiplication DA converter to which the value of the register 12 is supplied as the reference signal changes according to this scaling coefficient. Multiplication type D
The output of the A converter 14 is supplied as a reference signal to the multiplication DA converter 11 to which drawing data is supplied, and as a result,
The drawing data is converted into enlarged or reduced data in the multiplication DA converter 14 and output.

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 apparatus, and more particularly to a charged particle beam drawing apparatus which is optimal for use in scaling drawing data.

[0002]

2. Description of the Related Art In recent years, as the memory capacity of semiconductor memory devices has increased from 4M to 6M, and further to 64M bits, the density and precision have increased, and the electron beam drawing apparatus used in the manufacturing process of the device has also been increased. Higher precision and higher speed are required to support this. In the development of a device using an electron beam drawing apparatus, even if the same pattern data is used as a drawing condition, the development is advanced while gradually reducing the enlargement ratio of the drawing pattern included in the data and increasing the density. There is a need. On the other hand, in direct writing in which a necessary pattern is written by directly irradiating a wafer with an electron beam, it is necessary to use it together with conventional drawing using a stepper. In that case, it is necessary to subtly change the pattern size to perform drawing in order to match the size in electron beam drawing with the size in stepper drawing.

[0003]

The work described above is currently carried out by returning to the pattern data source level in CAD and recreating data, or by changing the pattern size by digital hardware operation. However, there is a problem in terms of accuracy due to the limited bit width (minimum LSB limitation), and it takes time (TAT) in the software operation (CAD).

This problem will be described in more detail with reference to the drawings. FIG. 1 shows a circuit configuration of a conventional pattern data processing. Reference numeral 1 is a CPU for transferring pattern data and controlling other components. .. The digital arithmetic circuit 2 includes a register 3 in which the scaling coefficient of the pattern is set by the CPU 1, a digital multiplier 4, a rounding processing circuit 5, and the like.
The pattern data processed by the digital arithmetic circuit 2 is supplied to the electron beam deflector 8 of the electron beam drawing apparatus via the DA converter 6 and the amplifier 7. Reference numeral 9 denotes an electron gun, and the electron beam EB generated from the electron gun 9 is deflected by the deflector 8 and is applied to the drawing material 10.
Other components necessary for the electron beam drawing apparatus, such as a focusing lens system, an optical system for shaping an electron beam, and a structure for moving materials are omitted.

In such a conventional apparatus, the data of the pattern P shown in FIG. 2, that is, the coordinates of the origin of the pattern P (X
1, Y1) and the dimension (x1, y1) of the pattern P are C
It is sent from PU1 to the digital multiplier 4. At this time, C
A scaling coefficient is set in PU1 to register 3. The multiplier 4 multiplies the supplied pattern data by the scaling coefficient, and the multiplication result is sent to the rounding processing circuit 3 for rounding the data. As a result of calculation by this digital calculation circuit 2, FIG.
The data of the pattern P shown in the above is the data of the pattern P ', that is, the coordinates (X2, Y2
) And the dimensions of the pattern P (x2, y2).
The converted data is sent to the deflector 8 via the DA converter 6 and the amplifier 7. The problem here is that, because of the operation bit length in the operation circuit 2, the minimum bit limit in the DA converter 6, and the bit width limit, rounding processing of data must be performed before DA conversion.
With the recent increase in the density of drawing, depending on how the rounding error occurs, the pattern patterns after scaling overlap,
Gaps, etc. have occurred, and the error cannot be ignored. Therefore, a method of increasing the bit width of the operation or the bit width of the DA converter can be considered, but there is a limit to that.

The present invention has been made in view of the above circumstances, and an object thereof is to realize a charged particle beam drawing apparatus capable of performing a drawing pattern scaling process with high accuracy.

[0007]

A charged particle beam drawing apparatus according to the present invention multiplies a first multiplication DA converter to which drawing data is supplied, scaling data of drawing data and a reference signal, A second multiplication type DA converter for supplying a multiplication output to the first multiplication type DA converter as a reference signal, and a charged particle beam deflector for drawing the output of the first multiplication type DA converter It is characterized in that it is configured to supply to.

[0008]

In the charged particle beam drawing apparatus according to the present invention, the first multiplication type DA converter to which the drawing data is supplied is subjected to the second multiplication type DA conversion for multiplying the scaling data of the drawing data by the reference signal. The output of the container is supplied as a reference signal to scale the drawing data.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 shows an embodiment of the present invention, in which the same parts as those in the conventional apparatus of FIG. C
The pattern data from PU1 is multiplied by the DA converter 11
The scaling coefficient from the CPU 1 is set in the register 12. The scaling coefficient set in the register 12 is a multiplication type DA to which a signal from the reference power supply 13 that generates a reference voltage or current is supplied.
It is supplied to the converter 14. The operation output of the multiplication DA converter 14 is supplied to the multiplication DA converter 11 as a reference signal. The output of the multiplication DA converter 11 is amplified by the amplifier 7 and then supplied to the deflector 8. The operation of such a configuration will be described below.

When scaling the drawing pattern,
The scaling coefficient is from CPU1 to register 12
Is set to. As a result, the output of the multiplying DA converter to which the value of the register 12 is supplied as the reference signal changes according to this scaling coefficient. The output of the multiplication type DA converter 14 is supplied as a reference signal to the multiplication type DA converter 11 to which the drawing data is supplied, and as a result, the drawing data is converted into data that has been enlarged or reduced in the multiplication type DA converter 14. Is output. The scaling-processed drawing data is amplified by the amplifier 7 and then supplied to the deflector 8, and the electron beam EB from the electron gun 9 is deflected according to the drawing data, and the drawing target material 1
At 0, a desired pattern is drawn. In this way, the reference signal from the reference signal source 13 is multiplied by the scaling coefficient, and the multiplication result is supplied to the DA converter 11 to which the drawing data is supplied as a reference signal.
It is possible to change the output gain of the DA converter 11 arbitrarily and with high resolution. Also, the multiplication DA converter 1
By increasing the bit length n of 4, the pattern length N becomes 1
The resolution of variable gain can be increased to a resolution of / 2 ⁿ . For example, when the pattern length N is an LSB (minimum resolution) value, a high resolution of 1/2 ⁿ of the LSB value is realized.

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.

[0012]

As described above, the charged particle beam drawing apparatus according to the present invention is provided with the first drawing data.
Since the output of the second multiplying DA converter for multiplying the scaling data of the drawing data by the reference signal is supplied to the multiplying DA converter of No. 2 as the reference signal, the drawing data is scaled. With this configuration, it is possible to perform drawing pattern scaling processing with high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram showing a conventional electron beam drawing apparatus.

FIG. 2 is a diagram for explaining data scaling.

FIG. 3 is a diagram showing an electron beam drawing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 1 ... CPU 9 ... Electron gun 10 ... Drawing material 11,14 ... Register 13 ... Reference power source

Claims (1)

[Claims] 1. A first multiplication type D to which drawing data is supplied.
An A converter and a second multiplication DA converter for multiplying the scaling data of the drawing data by the reference signal and supplying the multiplication output to the first multiplication DA converter as the reference signal. Charged particle beam drawing apparatus configured to supply the output of the multiplying DA converter of 1 to a deflector of the charged particle beam for drawing.