JPH05102017A - Dislocation checking mehtod of pattern in charged particle beam lithography - Google Patents

Abstract

PURPOSE:To surely detect whether the dislocation of a drawing pattern has been caused during a lithographic operation by a method wherein, before a graphic processing operation, the position of the pattern is found, the position of the pattern is found from the data of the pattern after the graphic processing operation and the dislocation of the pattern is checked on the basis of the difference between the two kinds of positions which have been found. CONSTITUTION:A subtracter 13 finds the difference between the following: the positional data of patterns (n) which are set in regions 11c, 11d; and the positional data of patterns (m) which are set in regions 12a, 12b. The value which has been found indicates the distance between the patterns (n) and the patterns (m) after a graphic processing operation. The difference in the distance between the patterns (n) and the patterns (m) which have been set in regions 11e, 11f before the graphic processing operation is found by means of a subtracter 14. The value which has been found by using the subtracter 14 is compared with the permissible value of the dislocation of a distance. Thereby, it is possible to detect the dislocation of the patterns at an early stage and surely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drawing data abnormality checking method in charged particle beam drawing in which a pattern is drawn on a material to be drawn by an electron beam or an ion beam.

[0002]

2. Description of the Related Art FIG. 5 is a conceptual diagram of an electron beam drawing system, in which 1 is a computer, 2 is a graphic processing circuit, and 3 and 4.
Are deflection amplifiers, and 5 and 6 are deflection electrodes for deflecting the electron beam. In such a system, the computer 1
The drawing data from is subjected to graphic division, trapezoidal processing, distortion correction calculation, etc. in the graphic processing circuit 2, and after such various processing, deflection signals corresponding to the pattern are output to the amplifiers 3, 4
It is supplied to the deflection electrodes 5 and 6 via.

[0003]

In such a system, when the pattern data of ,, shown in FIG. 6, are supplied from the computer 1 to the graphic processing circuit 2, various predetermined processes are performed. In the course of processing in the circuit 2, a calculation error or other error may occur, in which case incorrect drawing data is supplied to the deflection amplifiers 3 and 4. For example, the pattern data of FIG. 6 becomes the shifted pattern data such as'. When such a positional deviation of the pattern occurs, the existence of the deviation is not known at the time of occurrence, and after the drawing of all the patterns is completed and the drawn material is developed, visual inspection by an optical microscope or other The occurrence of the deviation can be known only after checking by the defect inspection. As a result, although the material and the chip portion in which the positional deviation of this pattern has occurred become unusable at that time, it takes a considerable time from the occurrence of the deviation to the discovery thereof, and The processing is completely wasted.

The present invention has been made in view of the above points, and an object thereof is to check a pattern deviation in charged particle beam drawing capable of early and surely detecting the occurrence of a pattern position deviation. There is a way to realize.

[0005]

A pattern deviation checking method in charged particle beam drawing according to the present invention performs graphic processing such as distortion correction processing on initial drawing pattern data, and based on the processed data, a drawing target material is drawn. In the charged particle beam drawing method adapted to perform the pattern drawing, the position of the drawing pattern is obtained from the drawing pattern data before the figure processing, and then the position of the drawing pattern is obtained from the drawing pattern data after the figure processing, The pattern shift is checked on the basis of the obtained two types of differences, and the distance between the pattern to be drawn and the drawing pattern drawn immediately before it is calculated from the initial drawing pattern data. Next, regarding the pattern data for which the distance is obtained, the pattern processed data is drawn immediately before the pattern to be drawn. Obtains distances between the image pattern is characterized in that so as to check the deviation of the pattern based on the difference of the two distances found the.

[0006]

According to the pattern deviation checking method in charged particle beam drawing according to the present invention, the position of the drawing pattern is obtained from the drawing pattern data before the figure processing, and then the drawing pattern position is obtained from the drawing pattern data after the figure processing. Then, the deviation of the pattern is checked based on the calculated difference between the two types, and the distance between the pattern to be drawn and the drawing pattern drawn immediately before that is calculated from the initial drawing pattern data. In the pattern data for which the distance is obtained, the distance between the pattern to be drawn and the drawing pattern drawn immediately before is obtained for the data after the graphic processing, and the calculated difference between the two types of distances is obtained. Based on this, the pattern shift is checked.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows an example of an electron beam writing system for carrying out the method according to the invention.
The same parts as those of the conventional system are attached with the same reference numerals and detailed description thereof will be omitted. In this embodiment, the drawing pattern data from the computer 1 is set in the register 7. In the register 7, the area 7 in which the length (X2, Y2) of each side of the pattern is set in the pattern data.
a, 7b and areas 7c, 7d in which the positions (X1, Y1) of the pattern are set. Reference numeral 8 is a register, and the position data of the pattern set in the areas 7c and 7d of the register 7 is supplied and set. Reference numeral 9 denotes a subtracter, which calculates the difference between the data set in the areas 7c and 7d of the register 7 and the data set in the areas 8a and 8b of the register 8. 10 is a register,
Areas 10a to 10d respectively include the area 7a of the register 7.
The data set in .about.7d is set as it is, and the data of the difference obtained by the subtractor 9 is set in the areas 10e and 10f. The data in register 10 is
It is supplied to the graphic processing circuit 2 and subjected to distortion correction calculation and the like. The drawing data processed by the graphic processing circuit 2 is
The lengths (X2 ', Y2') of the sides of the processed pattern are set in the areas 11a, 11b of the register 11 in the areas 11c, 11b.
The position (X1 ', Y1') of the processed pattern is set in d, and the register 10 is set in the areas 11e and 11f.
The difference data set in e and 10f is set as it is. 12 is also a register, and register 11
The position data (X1, Y1) of the pattern set in the areas 11c and 11d of is set. The data in the regions 11a and 11b of the register 11 is supplied to the deflection electrode 5 via the amplifier 3, and the regions 11e and 11 of the register 11 are supplied.
The data of f is supplied to the deflection electrode 6 via the amplifier 4, and the electron beam with which the material to be drawn is irradiated is deflected according to the data. 13 is a subtractor, which is a register 11
The difference between the data set in the areas 11e and 11f of the above and the data set in the areas 12e and 12f of the register 12 is obtained. Reference numeral 14 is also a subtractor, and finds the difference between the subtraction result of the subtractor 13 and the data set in the areas 11e and 11f of the register 11. Reference numeral 15 is a comparison circuit, which calculates the difference between the result of the subtracter 14 and the deviation reference value set in the register 16. The comparison result of the comparison circuit 15 is set in the register 17. 18, 19
Is a delay circuit, which delays the set signals from the computer 1 and the graphic processing circuit 2 and supplies them to the register 10 and the register 17, respectively. The operation of such a configuration will be described below.

Data of a specific pattern from the computer 1, that is, the lengths (X2, Y2) of each side of the pattern and the positions (X1, Y1) of the pattern are set in the areas 7a to 7d of the register 7. Further, in the initial stage, the inside of the register 8 is initially cleared. here,
The arbitrary pattern n shown in FIG. 2 and the pattern m drawn immediately before the n pattern will be described. When the n pattern is drawn, the n pattern data (X2n, Y2
n) and (X1n, Y1n) are set in the register 7 based on the set signal from the computer 1. At this time, the position data (X1m, Y1m) of the m pattern drawn immediately before the n pattern is set in the register 8. The subtractor 9 receives the position data of the n patterns set in the areas 7c and 7d of the register 7 and the area 8 of the register 8.
Differences Lx and Ly from the position signals of the pattern of m set in a and 8b are obtained. This difference is the distance between both patterns before the graphic processing of the patterns described later is performed. The data set in the areas 7a to 7d of the register 7 are set in the areas 10a to 10d of the register 10 based on the set signal delayed by the delay circuit 18, and at this time, the calculation results Lx and Ly of the subtractor 8 are also set. Area 10
e, 10f. The data set in the register 10 is supplied to the graphic processing circuit 2 and subjected to predetermined processing such as distortion correction calculation. The pattern data processed by the processing circuit 2 is stored in the area 11a-
It is set to 11f. At this time, the data of the pattern n has changed to (X2n ', Y2n'), (X1n ', Y1n'), and the distances Lx, Ly between the patterns are set in the areas 10e, 10f of the register 10. The data thus processed is set in the areas 11e and 11f. Here, the position data (X1m ', Y1m') after the graphic processing of the pattern m drawn immediately before is set in the areas 12a and 12b of the register 12, and the subtracter 13
Calculates the difference between the position data of the n patterns set in the areas 11c and 11d and the position data of the m patterns set in the areas 12a and 12b. The obtained values indicate the distances Lx 'and Ly' between the pattern of n and the pattern of m after graphic processing. Next, the values (Lx ', Ly') of the subtractor 13 are supplied to the subtractor 14, and the distances (L) between the patterns n and m before graphic processing set in the regions 11e and 11f in the subtractor 14 are set.
x, Ly) is obtained. The value obtained by the subtracter 14 represents the distance difference between the n and m patterns before and after the graphic processing. The subtraction result of the subtractor 14 is supplied to the comparison circuit 15, and the allowable value Ls of the distance deviation set in the register 16 from the computer 1 is set.
Compared to. If the deviation of the distance between the patterns in both the x and y directions is larger than the allowable value Ls, the graphic processing result of the n pattern becomes an error and "1" is stored in the register 17.
Is set. In this case, a shift detection interrupt signal is generated from the register 17 to the computer 1, and the computer 1 knows that the shift of the pattern exceeding the allowable value has occurred. With respect to the material or the chip having the pattern deviation, various processing steps thereafter are stopped and unnecessary processing is not performed. vice versa,
When the deviation of the distance between the patterns in both the x and y directions is smaller than the allowable value Ls, the graphic processing result of the n pattern is correct, and "0" is set in the register 17. In this case, the shift detection interrupt signal is not generated from the register 17 to the computer 1.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this embodiment. For example, register 8
, The position data of the pattern drawn immediately before is set, and the distance between the drawing pattern and the pattern drawn immediately before is obtained.
For example, the coordinate origin "0" may always be set, and the value of the register 12 may also be set to "0" so that the change in the position of each drawing pattern is monitored by the distance from the coordinate origin. However, in this case, since the distance from the coordinate origin to each pattern is longer than the distance between adjacent patterns, the bit length of the distance data becomes significantly long, and the calculation time in each subtractor becomes long. In addition, the probability of error occurrence in the processing circuit increases due to the long bits. Also,
It is effective to change the allowable deviation value set in the register 16 in accordance with the drawing area instead of making it constant. That is, as shown in FIG.
It is effective to divide into a, Sb, Sc, and Sn, and to set the deviation allowable value for each block. This is because the correction value of the correction calculation performed by the graphic processing circuit 2 differs depending on the drawing position of the material. In this case, among the drawing data, the corresponding allowable value may be read from the memory in which a plurality of allowable values are stored in advance using the position data as an address and set in the register 16. Furthermore, in the above-described embodiment, the case where the distortion correction calculation is performed has been described as an example. However, when the figure division processing is performed, for example, as shown in FIG. 4, the pattern m drawn immediately before is divided into nine pieces. If yes,
Substantially the same shape as when a new pattern is inserted between the pattern m and the pattern n. As a result, in order to obtain the pattern shift of the pattern n after the graphic processing, it is necessary to obtain the difference between the position (Pm9) of the last subdivided pattern m (9) of the pattern m and the position of the pattern n. is there. For that purpose, the configuration including the registers 7, 8, and 10, the subtractor 9, and the delay circuit 18 shown in FIG. 1 may be added to the next stage of the graphic division circuit in the graphic processing circuit 2. Although the above embodiment has been described by taking the electron beam writing as an example, the present invention can be applied to the ion beam writing.

[0010]

As described above, the pattern deviation checking method in charged particle beam drawing based on the present invention obtains the position of the drawing pattern from the drawing pattern data before the graphic processing, and then performs the pattern processing after the graphic processing. The position of the drawing pattern is obtained from the drawing pattern data, and the deviation of the pattern is checked based on the obtained two types of difference. Further, from the initial drawing pattern data, the pattern to be drawn and the drawing pattern drawn immediately before that are drawn. Then, the distance between the pattern data to be drawn and the drawing pattern drawn immediately before is calculated for the pattern data for which the distance is calculated. 2
Since the pattern shift is checked based on the difference in the seed distances, it is possible to detect the occurrence of the pattern shift in real time early and surely during drawing.

[Brief description of drawings]

FIG. 1 shows an example of an electron beam writing system for carrying out the method according to the invention.

FIG. 2 is a diagram showing two patterns that are continuously drawn.

FIG. 3 is a diagram for explaining an example in which a deviation allowable value is changed.

FIG. 4 is a diagram for explaining an embodiment in the case of performing graphic division processing.

FIG. 5 is a conceptual diagram of an electron beam writing system.

FIG. 6 is a diagram showing a drawing pattern.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Computer 2 ... Graphic processing circuit 3, 4 ... Amplifier 5,6 ... Deflection electrode 7,8,10,11,12,16,17 ... Register 9,13,14 ... Subtractor 15 ... Comparison circuit 18,19 ... Delay circuit

Claims (2)

[Claims] 1. A charged particle beam drawing method in which initial drawing pattern data is subjected to graphic processing such as distortion correction processing, and a pattern is drawn on a drawing material based on the processed data. Then, the position of the drawing pattern is obtained from the drawing pattern data, then the position of the drawing pattern is obtained from the drawing pattern data after the graphic processing, and the deviation of the pattern is checked based on the obtained difference between the two types. A method for checking pattern deviation in charged particle beam writing. 2. A charged particle beam drawing method, wherein initial drawing pattern data is subjected to graphic processing such as distortion correction processing, and a pattern is drawn on a drawing material based on the processed data. Then, the distance between the pattern to be drawn and the drawing pattern drawn immediately before that is obtained, and then the pattern data for which the distance is obtained, which is the pattern data to be drawn and its A pattern deviation checking method in charged particle beam drawing, wherein a distance from a drawing pattern drawn immediately before is obtained, and the pattern deviation is checked based on the obtained difference between the two types of distances.