JPH0231413A - Method of electron beam exposure - Google Patents

Abstract

PURPOSE:To reduce the memory capacity of an exposure device while facilitating the positive-negative inversion of patterns by a method wherein the beam are scanned in the same way as that of the vector scanning making reference to vector data processed from raster data. CONSTITUTION:A host computer 2 converts any gerber data read out of a magnetic tape 1 into raster data and after deciding if the data are to be inverted to negative or positive, the vector data are processed sideways from the raster data. After finishing the conversion, the host computer 2 transmits the vector data to an exposure device 4. The deflection signals shifted from the starting position X0 to the position X1 wait for the response time of a system and, after the beams are turned ON, to be shifted to the next position X2 where the beams are turned OFF and the deflection signals are shifted to the next position X3. The Y coordinates of the positions X2 and X3 are the same. Later, the same procedures are repeated to draw pictures on the specified patterns. At this time, the vector data are required simply of the coordinate of fulcrum and the length so that the memory 6 capacity of the exposure device 4 may be reduced while facilitating the negative and positive inversion.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electron beam exposure method that can draw minute graphic patterns on high-density integrated circuits, and in particular to an electron beam exposure method that improves drawing speed and reduces memory capacity. This invention relates to an electron beam exposure method.

[Prior Art] FIG. 4 is a diagram showing a beam scanning method of a conventional electron beam exposure apparatus disclosed in, for example, Japanese Unexamined Patent Publication No. 53-126277.

This beam scanning method is a method in which, after turning on the beam, the area that can be drawn with a brush is filled in and the object jumps to the next figure. That is, the small figure Ql to be exposed first
A computer (not shown) specifies the location of the data (
Specifically, the electron beam is positioned at the scanning starting point PL based on the coordinates of the scanning starting point PL when scanning the small figure Ql.

Next, the electron beam is repeatedly scanned five times as indicated by the arrow from the scanning start point P1 in the reference section Al, and a small figure Q1 is drawn. When the exposure of the small figure Q1 is completed, the computer specifies the positions of the small figures Q2 and Q3 in exactly the same way, and the small figures Q2 and Q3 are drawn in the reference section At following the small figure Q1.

After drawing the small figures Q1 to Q3 within the reference section Al as described above, the computer specifies the position of the reference section A2 to be exposed next, and sets the reference section A2 to be exposed sequentially in exactly the same way as in the case of the reference section Al. The sections are sequentially shifted in a zigzag pattern, and small figures within each reference section are exposed at high speed.

This beam scanning method is generally called a vector scanning method.

FIG. 5 shows another beam scanning method disclosed in, for example, Japanese Unexamined Patent Publication No. 62-86717, in which the pattern starting point X at the left end is used. The beam is changed to n and scanned to the pattern end point xof'T at the left end of this line, and this scanning is repeated hereafter.This method is exactly the same as the electronic scanning of a television's cathode ray tube, and is called the raster scanning method. ing.

In other words, beam ON, OF for all coordinate points
It takes 53.7 seconds to scan the entire drawing surface based on the F command, even if the drawing surface is scanned using a 14-bit D/A in X and Y coordinates and a clock frequency of 5 MHz. Also, ON.

The memory required for information regarding OFF also requires 214x214 bits. FIG. 6 is a bar graph diagram showing the beam irradiation amount at each coordinate point in this raster scanning method.

[Problems to be Solved by the Invention] Since the conventional electron beam exposure method uses the exposure method as described above, in the case of the vector scanning method, it is necessary to reverse the ON and OFF states of the beam depending on the properties of the resist. , there was a problem that negative and positive reversal was not possible.

In addition, in the case of the raster scanning method, although negative and positive inversion is easy, the beam has to be scanned, including unnecessary areas, so there are problems such as it takes time to scan and requires a large memory capacity. .

This invention was made with the aim of solving the above-mentioned problems, and it is an electron beam exposure method that can easily perform negative and positive reversal, shorten scanning time, and reduce memory capacity. The purpose is to obtain.

[Means for Solving the Problems] The electron beam exposure method according to the present invention converts a pattern into a collection of vectors in the same direction as the raster scan direction from the raster scan drawing position and beam ON/OFF information. ,
Based on this conversion data, the beam is scanned in the same manner as vector scanning.

[Operation] In the electron beam exposure method according to the present invention, vector data is created from raster data, and the electron beam is scanned using this vector data in the same manner as vector scanning. Therefore, negative and positive inversion is easy and the memory capacity can be reduced. Furthermore, data conversion eliminates the wasted time of deflecting the beam to areas where it is not irradiated, resulting in a significant reduction in scanning time.

[Example] An example of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) is a magnetic tape on which information on a substrate (not shown) is recorded using the Gerber data method;
) is a host computer as a calculation means connected to a magnetic tape (1) and a large capacity memory (3), and (4) is a host computer (2) connected via a data transfer line (5).
(6) is a small capacity memory connected to the exposure device (4).

Next, the operation will be explained. Host computer (2)
First, the Gerber data read from the magnetic tape (1) is converted into raster data.

After deciding whether to invert the negative or positive, create horizontal vector data from the raster data. After the conversion is completed, the host computer (2) transfers the data to the exposure device (4).

In this case, vector data only needs to have the fulcrum coordinates and length, so the data transferred here and the memory capacity required by the exposure device can be significantly reduced, and negative and positive inversion can also be carried out. It's easy.

FIG. 2 is an explanatory diagram of creating a negative pattern based on data from the host computer. In FIG. 2, the deflection signal is first moved from the start position Xo to the position X1, waits for the response time of the system, and then moves to the position X2 where the beam irradiation amount is increased.

Therefore, the beam is moved to 0FFL and the change signal is moved to position X. The Y coordinates of position X2 and position X3 are the same. After that, the desired pattern is drawn by repeating the same process.

The difference from the drawing operation using the vector scanning method is that the vector always faces, for example, in the X-axis stop direction, and the seven wheel coordinates are sequentially scanned from one direction.

Also, the difference from the drawing operation using the raster method is that the Y
If there is no point to be exposed at all when viewed from the axis, do not scan the row corresponding to that Y-axis at all, and even if you add a location where the beam does not need to be turned on even in the - row, never use it as a reference. is not given.

In Figure 2, the parts drawn with solid lines other than the coordinate axes are
This is the part that you want to actually irradiate and expose with the beam. A type in which a pattern is generated in the area irradiated with the beam in this manner is called a negative pattern.

This name comes from the method that used a mask film in conventional ultraviolet exposure.

FIG. 3 is an explanatory diagram of creating a positive pattern by inverting the 0N10FF of the beam shown in FIG. 2, and is intended to generally correspond to high density and fineness of this positive pattern.

Therefore, the exposure device (4) that generates the beam is required to be able to handle and convert both negative and positive patterns.

Note that in the above embodiment, an electron beam was explained, but
A charged beam such as an ion beam may also be used, and the same effects as in the above embodiment can be achieved.

Furthermore, instead of one exposure apparatus exclusively using one host computer, it is also possible to transfer data from one host computer to a number of exposure apparatuses.

[Effects of the Invention] As described above, according to the present invention, since the beam is scanned from raster data to vector data in the same manner as vector scanning, the memory capacity of the exposure apparatus can be reduced, making the apparatus less expensive. can be achieved, resulting in high throughput. In addition, there are effects such as easy reversal of positive and negative patterns.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus for carrying out an electron beam exposure method according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of negative pattern creation by the method of the invention, and FIG. 3 is an illustration of the creation of a positive pattern by the method of the invention. 4 is an explanatory diagram of the conventional vector scanning method, FIG. 5 is an explanatory diagram of the conventional raster scanning method, and FIG. 6 is a bar graph diagram showing the beam irradiation amount in the raster scanning method. In the figure, (2) is the calculation means (host computer)
, (4) is an exposure device. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1: A block diagram showing the example device Figure 1: An explanatory diagram of negative pattern creation Figure 2: Agent: Masuo Oiwa, patent attorney (and 2 others) Figure 3: an explanatory diagram of positive pattern creation

Claims (1)

[Claims] In an electron beam exposure method in which a resist coated on a substrate is irradiated with an electron beam to form a predetermined pattern,
An electron beam exposure method characterized in that the pattern is converted into a collection of vectors in the same direction as a raster scan direction, and the electron beam is scanned in the same manner as vector scan based on this conversion data.