JPH0691002B2 - Electron beam drawing method and apparatus - Google Patents

Description

The present invention relates to an electron beam writing method and apparatus for irradiating a substrate such as a semiconductor integrated circuit with an electron beam to draw a pattern on the substrate, and more particularly to an electronic computer. Enlargement or reduction of a shot that prevents double exposure or pattern breaks between adjacent shots by hardware at the time of actual drawing, without performing time-consuming enlargement or reduction processing of the shot data using software. Accordingly, the present invention relates to an electron beam drawing method and apparatus using shot data that enables sizing processing in real time.

(Summary of the Invention) The gist of the present invention is that in the variable shaping electron beam drawing method, the sizing of the shot is not performed by software processing by an electronic computer, but the sizing processing is performed by hardware during actual drawing. It is a point.
For this purpose, the shot data with connection information between adjacent shots is used, and the electron beam equipped with an arithmetic circuit for calculating the position, width and height of the shot from the connection information and the given sizing amount. This can be achieved by constructing a drawing device.

(Prior art and its problems) In pattern formation using an electron beam drawing apparatus, in order to obtain a desired pattern width, enlargement or reduction processing of a shot, that is, sizing, is performed depending on the type of resist, the configuration, the type of base film, etc. Processing is required.

For example, consider a case where one rectangular pattern is drawn with nine shots as shown in FIG. To enlarge this rectangular pattern by δx in the x direction and δy in the y direction, nine shots must be prepared as shown in FIG. These nine shots are obtained by moving only the side marked with a circle in FIG. 4, that is, the side without an adjacent shot. ×
If the side marked with is moved, double exposure or pattern breakage occurs, so it cannot be moved.

Conventionally, this involves sizing processing of design data by software using an electronic computer to create shot data, but there is a problem that conversion takes time and the turnaround time increases. On the other hand, a method of sizing the shot unconditionally in real time by changing the coefficient of the beam control system of the electron beam drawing apparatus is also performed, but since the positional relationship between adjacent shots is not considered, Inconveniences such as double exposure or pattern breakage occurred on the side marked with X.

(Means for Solving Problems) The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above problems in a conventional electron beam drawing apparatus, to improve pattern accuracy and turn. An object of the present invention is to provide an electron beam drawing method and apparatus using a shot data format that can improve the surround.

(Example) Hereinafter, the Example of this invention is described based on drawing.

FIG. 1 (a) is a diagram showing a data format which is an embodiment of the present invention. The shape and dimensions of the shot are shown in FIG. The drawing shot data usually consists of at least the position, width and height of the shot,
These data are sent to a beam shaping system, a beam blanking system, a beam deflecting system, and a stage system to realize a desired beam shape at a desired position on the substrate. 4 bits on the right end are connection information newly added in the present invention, corresponding to each side of a, b, c, d of the shot, 0 is connection or "move not possible", 1 is not connection or "move" It means “OK”. An example of this connection information is that of the shot S ₀ in FIG. 2, where the sides a, b, and c are “movable” and the side d is “movable”.

FIG. 3 is a diagram showing a schematic configuration of an electron beam drawing apparatus having a sizing arithmetic circuit according to an embodiment of the present invention.
In the figure, 10 is an electron beam drawing apparatus main body, and an electron gun 1
1, the first shaping aperture 12, the shaping deflector 13, the second shaping aperture 14, the reduction lens 15, and the deflector 16. Reference numeral 17 is a wafer as an example of a drawing target. Further, 20 is a storage unit for storing shot data, 30 is a register circuit for storing the enlargement / reduction amount of the shot, 40 is a sizing arithmetic circuit, 50 is a buffer memory, and 60 is a CPU for controlling each of the above circuits.

The operation of this embodiment will be described below with reference to FIG. The shot data in the shot data storage unit 20 is transferred to the buffer memory 50 prior to drawing. The shot data is transferred to the sizing arithmetic circuit 40 in the order of shots. Here, together with the sizing amount transferred in advance, the sized shot data calculated according to the connection information is transferred to the beam control system to perform the actual sizing.

For example, as shown in FIG. 1 (a), [x ₀ , y ₀ , w ₀ , h ₀ , 1,1,1,
0] becomes Shiyotsutodeta this calculation if (Shiyotsuto S ₀ of FIG. 2) is transferred to the sizing operation circuit 40 can be expressed as follows.

_{x = x 0 -d · δx y} = y 0 -c · δy w = w 0 + (b + d) · δx h = h 0 + (a + c) · δy a, b, connection information c sides 1 ie not connected Because y ₀ ,
The sizing amount is added to or subtracted from w ₀ and h ₀ , and the data is sent to the beam control system. At this time, since the side d facing the side b does not move, the sizing for w ₀ is δx, but the side c facing the side a moves, so h ₀
Is 2δy. On the other hand, since the connection information on the d side is 0, that is, the connection, no calculation is executed for x, and data that does not add or subtract the sizing amount is sent to the beam control system. With this configuration, sized shot data corresponding to S in FIG. 2 can be obtained.

The connection information can be added by a program that converts design data into shot data, but in an electron beam drawing device that has a circuit that repeatedly develops data and a circuit that further divides the shot data, it can also be generated within the device. Is possible. That is, when converting design data into shot data, a rectangle that cannot be drawn in one shot is divided into a plurality of shots having a maximum shot size or less, but connection information between shots can be calculated at the time of division. . Further, the connection information can be calculated because the repeated data is also created by the program. The circuit for further dividing the shot data implements the algorithm of the above program by hardware, and thus the connection information can be calculated similarly.

(Effects of the Invention) As described above, the present invention provides a time-consuming electronic computer by using the connection information of the sizing arithmetic circuit combined with the hardware provided in the electron beam drawing apparatus and the connection. There is an advantage that the sizing process can be performed in real time at high speed by hardware without performing the sizing process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a) is an explanatory view of a data format which is an embodiment of the present invention, FIG. 1 (b) is a view showing the shape and dimensions of a shot, and FIG. 2 is the present invention. FIG. 3 is a diagram used for explaining the operation of FIG. 3, FIG. 3 is a diagram showing a schematic configuration of an electron beam drawing apparatus which is an embodiment of the present invention, and FIG. 4 is an explanatory diagram for drawing a pattern with a plurality of shots. FIG. 5 is an explanatory diagram of a shot when the pattern of FIG. 4 is sized. 10: Electron beam lithography system main body 20: Shot data storage unit 30: Register circuit 40: Sizing circuit 50: Buffer memory 60: CPU

Claims (2)

[Claims] 1. An electron beam is controlled on the basis of shot data which specifies at least the position, width and height of the shot,
In the electron beam drawing method for drawing a desired pattern, connection information indicating whether or not each side of the shot is connected to another adjacent shot is added to each shot data, and the connection is performed when enlarging or reducing. Based on the information, calculate the position, width, and height of the relevant shot with the side that is not connected to other adjacent shots moved by the given enlargement or reduction amount, and draw with this calculated shot data. An electron beam drawing method characterized by: 2. Short data and sizing amount including at least data for specifying the position, width and height of the shot, and connection information indicating whether or not each side of the shot is connected to another adjacent shot. Calculates the position, width and height of the relevant control device that sends each of the shots, and the position of the relevant shot in the state where the side that is not connected to the other adjacent shots is moved by the sizing amount according to the above-mentioned shot data and sizing amount. An electron beam drawing apparatus, comprising: a sizing circuit for controlling the sizing circuit;