JPS59181615A - Luster type beam drawing device - Google Patents

Abstract

PURPOSE:To adjust beams projected onto a body to be drawn instantaneously and with high accuracy by controlling a data transfer rate and the speed of beam deflection in response to the speed of beams so that the width of beam deflection is made constant in order to adjust the beams. CONSTITUTION:Beam-intensity data are read from a control data generator 21, and deflection control data are prepared and outputted so that the speed of beam deflection corresponding to the data is obtained. When the operation of a deflection circuit 27 and a blanking circuit 24 is started by a synchronous signal from a synchronous circuit 25, data transfer-rate data are prepared on the basis of beam-intensity data and transmitted over a clock adjusting circuit 26. Accordingly, the blanking rate of the blanking circuit 24 is controlled, the deflection width of beams on a body to be drawn 10 is made constant regardless of the speed of deflection, and intensity corresponding to beam-intensity data is obtained as beam intensity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a raster beam lithography system used in the manufacture of semiconductor integrated circuits, and particularly relates to a raster type beam lithography system used in the manufacture of semiconductor integrated circuits, and particularly to a raster type beam lithography system used for manufacturing semiconductor integrated circuits. The present invention relates to a control device for highly accurate control.

[Technical background of the invention]

This type of raster beam lithography apparatus, for example, an electron beam lithography apparatus, deflects the beam B in a fixed direction (X direction) at a constant speed and turns the beam on and off, as shown in FIG. By controlling whether or not drawing can be performed on the drawing substrate 1, and repeating the drawing control described above each time the drawing target substrate 1 is moved by a certain amount in the direction (Y direction) perpendicular to the beam deflection direction, a figure can be drawn on the substrate 1. It is a drawing of a pattern.

Incidentally, one unit of the writing address of the writing pattern corresponds to the size of the beam diameter, and it may be necessary to control the dimensions of the writing pattern within the range of the writing address unit or less. In this case, conventionally, the above dimensions and dimensions have been controlled by mainly changing the magnitude of the beam current and changing the intensity of the beam irradiated onto the beam renost on the drawing substrate.

[Problems with background technology]

However, as mentioned above, when the magnitude of the beam current is changed, the beam diameter, which has a strong relationship with the writing pattern accuracy,
Since the focal position, beam rotation angle, beam position, etc. also change at the same time, it is necessary to remeasure and readjust these parameters. In this case, a series of adjustments of the electron beam column system,
For example, there is a drawback that it usually takes 1 to 2 minutes to adjust the electronic lens O. In addition, since there are many adjustment items, there is a drawback that sufficient overall setting accuracy cannot be obtained.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a raster type beam drawing apparatus that can adjust the intensity of a beam irradiated onto an object to be drawn with high precision and at high speed.

[Summary of the invention]

That is, the raster type beam drawing apparatus of the present invention includes a deflection means that repeatedly performs beam deflection scanning to deflect the beam by a certain width in a certain direction, and a deflection means that repeatedly performs beam deflection scanning to deflect the beam by a certain width in a certain direction, and turns on and off irradiation of the beam to the object to be drawn according to graphic data. and a beam intensity control means that controls the speed of beam deflection scanning by the deflection means according to beam intensity data and controls the transfer rate of a beam on/off control signal to the blanking means. It is characterized by comprising:

Therefore, there is no need to adjust the electron lens barrel system at all, and the beam intensity can be adjusted at high speed and with high precision simply by electronically controlling the data transfer rate and beam deflection speed.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A raster-type electron beam drawing apparatus to which an embodiment of the present invention is applied will be described in detail below with reference to the drawings.

In FIG. 2, an electron beam drawing apparatus main body 20 has an XY stage 11 for fixing the object 10 to be drawn. The XY drive motor 12 is for driving the XY stage 11 in the horizontal direction (X direction) and the vertical direction (Y direction). An electron gun 13 is provided between the electron gun 13 and the XY stage 11, and a condenser lens 14 that focuses the electrons emitted from the electron gun 13, and a condenser lens 14 that focuses the electrons emitted from the electron gun 13, and Irradiation to (
a blanking electrode 15 that controls irradiation (on) and irradiation release (off), and a deflection electrode 1 that scans the electron beam.
6 are provided in sequence.

On the other hand, 21 is a drawing device control data generator, which generates graphic data and beam intensity data. 22 is a computer system, and the control data generator 21
In addition, it is connected to various circuits to be described later, and exchanges data and control signals with these circuits, as well as performs necessary data processing. The drawing dot pattern memory 23 stores the drawing dot pattern data corresponding to the graphic data generated from the control data generator 21 in the computer system 2.
Enter from 2 and store this temporarily. The blanking circuit 24 starts a blanking control operation in synchronization with a synchronization signal from a synchronization circuit 25, and controls the blanking electrode 15 to be turned on or off in accordance with dot pattern data input from the driver A turn memory 23. do. The clock adjustment circuit 26 adjusts the clock output frequency according to the data transfer rate data given from the computer system 22 based on the beam intensity data generated from the control data generator 21 to adjust the blanking rate by the blanking circuit 24. control. The deflection circuit 27 starts the deflection operation in synchronization with the synchronization signal from the synchronization circuit 25, and starts the deflection operation in synchronization with the computer system 22 based on the beam intensity data.
The slope of the waveform of the deflection voltage is controlled according to the beam deflection speed data given from the deflection electrode 1.
Supply to 6. The XY stage drive control circuit 28 controls the moving speed of the xy stage 11 according to data inputted from the computer system 22 based on beam intensity data, and also controls the moving speed of the xy stage 11 based on measurement data outputted from a position measurement circuit 29, which will be described later. The XY drive motor 12 is used to drive and control the XY drive motor 12 so as to control the position of the XY stage 11 in accordance with data given from the combiner system 22. The laser interferometer 30 is for detecting changes in the position of the XY stage 1 using laser light. The position measurement circuit 29 is
Position data of the XY stage 11 is measured based on the detection output of the laser interferometer 30. Note that the deflection circuit 27 corrects the deflection voltage according to bias data given from the computer system 22 based on the measurement data of the position measurement circuit 29. This is to correct the drawing position with respect to the object to be drawn 10 on the beam scanning side when (1) the positioning accuracy of the object to be drawn 10 by the stage 11 cannot be obtained sufficiently.

Next, before explaining the operation of the above electron beam lithography system,
First, the principle of adjusting beam intensity will be described. Generally 8. The relationship among beam intensity (D), current (I), Plankingley (R), deflection speed (S), and deflection width (5) is expressed by the following equation.

WOCR-8・・・・・・(2) In order to change the beam intensity, conventionally the beam current (I)
However, in the device of the present invention, instead of changing the beam current (I), the beam deflection speed (S) is changed so as to keep the beam deflection width (5) constant, and the blanking rate (S) is changed in synchronization with this. R: the transfer rate of the signal that controls the beam on and off) is changed.

FIG. 3 shows a flowchart of the beam drawing control operation by the conbeater system 22. That is, in the first step Sl, XY stage drive control data is created and outputted so as to set the XY stage 11 at the next drive start position based on the position data from the position measurement circuit 29. In the second step S2, graphic data is read from the control data generator 2, converted into drawing dot pattern data, and stored in the dot pattern memory 23. Third
In step S3, bit intensity data is read from the control data generator 21, and deflection control data is created and output so that a beam deflection speed corresponding to the data can be obtained. Then, when the deflection circuit 27 and the blanking circuit 24 start operating according to the synchronization signal from the synchronization circuit 25,
Data transfer rate data is created based on the bit strength data and sent to the clock adjustment circuit 26. KoiKyoshi,
The blanking rate of the blanking circuit 24 is controlled, the deflection width of the beam on the object 10 to be drawn remains constant regardless of the deflection speed, and the beam intensity is obtained in accordance with the bit intensity data. When one beam scan in the X direction is completed in this way, the XY stage 1 is moved by a certain amount in the Y direction in a fourth step S4. Then, the first to fourth steps 81 to S4 are performed until the drawing in the Y direction is completed.
The control is repeated. In the fourth step S4, the XY stage drive control data output is set to control the moving speed of the XY stage 1 in the Y direction according to the data transfer rate. When the Y-direction scanning is completed in this manner, beam writing is again performed on the adjacent xy scanning plane based on new graphic data. Note that the conversion from the graphic data to the drawn dot pattern data is not limited to the converter system, and a dedicated conversion circuit may be used. However, the order of the first step fSl and the second step S2 may be reversed. Furthermore, if all of the graphic data is converted into drawing dot and turn data, the above data conversion can be omitted during the second and subsequent beam scans in the X direction. It is also possible to fix the moving speed of the XY stage 11 in the Y direction to the value at the lowest data transfer rate. However, the drawing speed will be slower.

According to the above-described electron beam drawing apparatus, in order to adjust the intensity of the beam irradiated onto the object to be drawn when controlling the dimensions of the drawing pattern in units of drawing addresses, the electron beam barrel system does not move at all, and the beam The data transfer rate and beam deflection speed are controlled according to the beam intensity so that the deflection width is constant. Therefore, the beam intensity can be adjusted instantaneously (at high speed 9 and with high precision).

In addition, according to the above-mentioned apparatus, it is easy to perform drawing on the same object by partially changing the beam intensity.
It becomes possible to frequently change this partial beam intensity U, and it also becomes possible to change the beam intensity for each X-direction scan.

Furthermore, the present invention is not limited to electron beam lithography apparatuses, but is also applicable to lithography apparatuses that use ion beams, laser beams, etc. other than electron beams.

〔Effect of the invention〕

As described above, according to the raster type beam drawing apparatus of the present invention, it is possible to adjust the intensity of the beam irradiated to the temporary drawing body with high precision and at high speed when controlling the dimensions of the drawing pattern below the drawing address unit. Furthermore, it can be used to improve the productivity of semiconductor integrated circuits.

[Brief explanation of drawings]

Fig. 1 is a diagram shown to explain the state of beam drawing on an object to be drawn in the raster type beam drawing Im device;
The figure is a perspective view of the configuration of an embodiment of the raster type beam drawing apparatus according to the present invention, and FIG. 3 is a flowchart showing an example of the control procedure by the computer system in FIG. 2. 10... object to be drawn, 1no... XY stage, 12.
...XY drive motor, 15...Blanking ti, 1
6... Deflection electrode, 20... Electron beam lithography apparatus main body, 2. ? . . . Computer system, 23 . . . Drawing drawer and turn memory, 24 .

Claims (1)

[Claims] A deflection means that repeatedly performs beam deflection scanning to deflect the beam by a certain width in a certain direction, a blanking hand i that controls on/off irradiation of the beam to the object to be drawn according to graphic data, and a blanking means that controls the beam intensity data. A raster type beam drawing characterized by comprising a beam intensity control means for controlling the speed of beam deflection scanning by the deflection means and controlling the transfer rate of a beam on/off control signal to the blanking means. Device.