JPH0779074B2 - Electron beam exposure method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam exposure method capable of drawing a minute graphic pattern on a high-density integrated circuit, and more particularly to an electron beam exposure method utilizing a vector scanning method. Is.

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

With this beam scanning method, after turning on the beam, the area that can be drawn with a single stroke is filled and the next figure is jumped to. That is, the electron beam is first scanned based on the data (specifically, the coordinates of the scanning start point P1 when scanning the small figure Q1) designated by the computer (not shown) for the position of the small figure Q1 to be exposed first. It is located at the scanning start point P1.

Next, the electron beam is repeatedly scanned from the scanning start point P1 in the reference section A1 five times as shown by the arrow, and the 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 figure is set in the reference section A1.
Q2 and Q3 are drawn following Q1.

After drawing the small figures Q1 to Q3 in the reference section A1 as described above, the computer specifies the position of the reference section A2 to be exposed next, and the references to be sequentially exposed in the same manner as in the case of the reference section A1. The sections are sequentially shifted in a zigzag manner, and the small figures in each reference section are exposed at high speed.

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

Figure 5 is a representation of another beam scanning method shown in JP example Sho 62-86717, the beam scanning method, the beam is deflected moved to the left end of the pattern start point X _on,
The pattern is scanned to the pattern end point X _{off at} the right end of this line, and this scanning is repeated thereafter, which is just the same method as the electron beam scanning of a cathode ray tube of a television and is called a raster scanning method.

That is, scanning all the drawing surface based on the beam ON / OFF command for all coordinate points means, for example, that the drawing surface has X- and Y-coordinates 14-bit D / A, clock frequency 5
Even scanning in MHz takes 53.7 seconds. Also, ON, OFF
The memory required for information about 2 ¹⁴ × 2 ¹⁴ bits is also required. FIG. 6 is a bar graph 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 is based on the above-described exposure method, in the case of the vector scanning method, ON / OFF of the beam is reversed depending on the property of the resist, that is, However, there was a problem that negative and positive reversals were not possible.

Further, in the case of the raster scanning method, although the negative and positive inversions are easy, there is a problem in that the beam must be scanned including an unnecessary portion, which requires a long scanning time and a large memory capacity. .

The present invention has been made to solve the above problems, and provides an electron beam exposure method capable of easily performing negative and positive inversion and simultaneously shortening the scanning time and reducing the memory capacity. The purpose is to get.

[Means for Solving the Problems] In the electron beam exposure method according to the present invention, data on which an exposure pattern is recorded is converted into raster data, and then negative data or positive data is selected and then reconverted into vector data. The electron beam is scanned based on this vector data.

[Operation] In the electron beam exposure method according to the present invention, data on which a pattern is recorded is converted into raster data, and then negative data or positive data is selected, and then reconverted into vector data.
The electron beam is scanned based on this vector data. Therefore, it is possible to easily select either the negative data or the positive data.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, (1) is a magnetic tape on which information on a substrate (not shown) is recorded by the Gerber data system,
(2) is a host computer as an arithmetic means connected to the magnetic tape (1) and the large capacity memory (3), (4) is an exposure device connected to the host computer (2) via a data transfer line (5), (6) is a small capacity memory connected to the exposure device (4).

Next, the operation will be described. Host computer (2)
Converts the Gerber data read from the magnetic tape (1) into raster data. After selecting whether to invert the negative or positive, the raster data is re-converted to horizontal vector data. After the conversion into vector data is completed, the host computer (2) transfers the data to the exposure device (4).

In this case, since the vector data need only have the coordinates and length of the starting point, the data transferred here and the memory capacity that the exposure apparatus must have can be greatly reduced, and negative and positive inversion can be performed. It's easy.

FIG. 2 is an explanatory diagram for creating a negative pattern based on the data from the host computer. In FIG. 2, first, the deflection signal moved from the start position X ₀ to X ₁ waits for the response time of the system, and after the beam is turned on, the position X ₂
Move up to.

Therefore, the beam is turned off and the deflection signal moves to the position X ₃ . The Y coordinates of position X ₂ and position X ₃ are the same. After that, the same pattern is repeated to draw a desired pattern.

The difference from the drawing operation by the vector scanning method shown in FIG. 4 is that the vector is always in the X-axis direction,
That is, the Y-axis coordinate is sequentially scanned from one direction.

In addition, the difference from the drawing operation by the raster method is that Y
If there is no point to be exposed when viewed from the axis, one row corresponding to the Y axis is not scanned at all, and even if there is a point where the beam does not need to be turned on even for one row, it is absolutely given as a reference. That is not the case.

In Fig. 2, the solid lines other than the coordinate axes are
This is the part where you want to actually irradiate and expose the beam. A type in which a pattern is generated in a portion irradiated with a beam is called a negative pattern. This is the name derived from the method that used a mask film in conventional ultraviolet exposure.

FIG. 3 is an explanatory diagram for forming a positive pattern by reversing the ON / OFF of the beam shown in FIG. 2, and this positive pattern is generally for high density and fineness.

Therefore, it is required that the exposure device (4) for generating the beam can be easily selected in correspondence with both the negative pattern and the positive pattern.

Although the electron beam has been described in the above embodiment,
A charged beam such as an ion beam may be used, and the same effect as that of the above-described embodiment is obtained.

Further, one host computer is not exclusively used by one exposure apparatus, but data can be transferred from one host computer to many exposure apparatuses.

[Effects of the Invention] As described above, according to the present invention, an electron beam is generated based on vector data reconverted after converting data on which a pattern is recorded into raster data, selecting negative data or positive data. Since the scanning is performed, it is possible to easily select either the negative data or the positive data, further shorten the scanning time, and reduce the memory capacity of the electron beam exposure apparatus.

[Brief description of drawings]

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 formation according to the present invention, and FIG. 3 is explanation of positive pattern formation according to the present invention method. 4 and 5 are explanatory views of a conventional vector scanning method, FIG. 5 is an explanatory view of a conventional raster scanning method, and FIG. 6 is a bar graph showing a beam irradiation amount in the raster scanning method. In the figure, (2) is a calculation means (host computer), and 4 is an exposure apparatus.

Claims (2)

[Claims] 1. An electron beam exposure method for irradiating a resist coated on a substrate with an electron beam to form a predetermined pattern, wherein the data recorded with the pattern is converted into raster data and then used for a negative or positive image. An electron beam exposure method, which comprises re-converting into vector data after selecting whether to use, and scanning the electron beam based on the vector data. 2. The electron beam exposure method according to claim 1, wherein the vector data is reconverted into vector data in the same direction as the scanning direction of the raster data.