JP2577498B2 - Charged particle beam exposure method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Charged particles in which a polygon forming plate having a polygonal transmission pattern formed thereon and a block mask having a plurality of block patterns are arranged on the optical axis. A charged particle beam exposure method in a beam exposure apparatus, which aims to facilitate irradiation when a charged particle beam shaped into a polygon by a polygon forming plate is partially irradiated to a block pattern. When the charged particle beam is partially irradiated on the block pattern, the irradiation area of the charged particle beam is treated as one block, and the value of the deflection amount when the charged particle beam is partially irradiated on the block pattern is distinguished. When the block pattern is given a block identification number and the charged particle beam is partially irradiated on the block pattern, The charged particle beam is deflected using the block pattern selecting deflector based on the identification number.

[Industrial Application Field] The present invention relates to a charged battery having a polygon-shaped plate formed with a polygonal transmission pattern and a block mask formed with a plurality of block patterns arranged on an optical axis. The present invention relates to a charged particle beam exposure method in a particle beam exposure apparatus.

[Prior Art] Conventionally, as an electron beam exposure apparatus which is an example of a charged particle beam exposure apparatus, an electron beam exposure apparatus whose main part is shown in FIG. 3 has been proposed.

In the figure, reference numeral 1 denotes an electron gun, which is provided with a cathode electrode 2, a grid electrode 3, and an anode electrode 4.

5 is an electron beam, 6 is a rectangular shaping aperture for shaping the electron beam 5 into a rectangle, 7 is an optical axis, 8 is an electromagnetic lens that converges the electron beam 5 formed into a rectangle, 9 is a variable rectangle, a variable triangle, etc. A deflector 10 for shaping the electron beam is an electromagnetic lens for converting the electron beam 5 into a parallel beam.

Further, 11 is a block mask, 12 is a mask moving mechanism that translates the block mask 11 as necessary,
As shown in FIG. 4, the block mask 11 sets an area 14 called an area on the substrate 13 and
In FIG. 14, as shown in FIG. 5, an area called a block
15, a desired transmission pattern, that is, a so-called block pattern 16 is formed in the block 15.
Here, the area 14 is an area that is set in units of the area where the electron beam 5 can be deflected.
The selection of 14 is performed by moving the block mask 11 by the mask moving mechanism 12.

In FIG. 3, reference numeral 17 denotes a mask deflecting unit for selecting a desired block pattern from among the block patterns 16 formed on the block mask 11, and the mask deflecting unit 17 comprises an electrostatic deflector. It is configured by arranging four deflectors 18-21. Here, the electron beam 5 is deflected by the deflector 18 in the direction of the selected block pattern 16, then deflected in the vertical direction by the deflector 19, and passes through the selected block pattern 16. The electron beam 5 passing through the block pattern 16 is deflected by the deflector 20
After being deflected toward the optical axis 7, the light is placed on the optical axis 7 by the deflector 21.

Reference numeral 22 denotes an electromagnetic lens that converges the electron beam 5 converted into a parallel beam, 23 denotes a blanking electrode that controls the blocking and passage of the electron beam 5, 24 denotes a reduction lens, 25 denotes an aperture aperture, and 26 and 27 denote projection lenses. , 28 are a main deflector (main deflector) composed of an electromagnetic deflector, 29 is a sub deflector (sub deflector) composed of an electrostatic deflector, 30 is a wafer as a sample,
Reference numeral 31 denotes a wafer stage on which the wafer 30 is mounted.

In such an electron beam exposure apparatus, since the block mask 11 on which various block patterns 16 are formed is used, the throughput is higher than that of the electron beam exposure apparatus configured to expose all the patterns by the variable rectangular method. be able to.

[Problems to be Solved by the Invention] In such a conventional electron beam exposure apparatus as well, if a rectangular block pattern 16A as shown in FIG. The electron beam 5 can be shaped into rectangles 5A of various sizes. Therefore, if a triangular block pattern 16B as shown in FIG. 7 is formed on the block mask 11, the electron beam 5 is deflected, for example, as indicated by an arrow 34, so that the electron beam 5 is deflected. It can be formed into triangles 5B of various sizes similar to 16B. As described above, in such an electron beam exposure apparatus, it is possible to partially irradiate the electron beam 5 with respect to any transmission pattern. In such a case, the number of block patterns is substantially reduced. As a result, the throughput can be improved.

In view of the above, the present invention facilitates irradiation when a charged particle beam such as an electron beam formed into a polygon by a polygon forming plate is partially irradiated to a block pattern formed on a block mask. It is an object of the present invention to provide a charged particle beam exposure method capable of performing the above.

[Means for Solving the Problems] The charged particle beam exposure method according to the present invention provides
A polygon forming plate formed by forming a polygonal transmission pattern,
A block mask formed with a plurality of block patterns, and a block pattern selecting deflector for selecting the block pattern are arranged, and the charged particle beam generated from a charged particle beam source is formed by the polygon forming plate. Charged particles for irradiating the selected one of the plurality of block patterns entirely or partially to form a desired pattern, and then exposing the sample to light. In the beam exposure method, the irradiation area of the charged particle beam when the charged particle beam is partially irradiated on the block pattern is treated as one block, and the charged particle beam is partially irradiated on the block pattern. Block identification number to distinguish the value of the amount of deflection in If partially irradiating a beam to the block pattern, is that the charged particle beam by using the block pattern selecting deflector deflects based on said block identification number.

[Operation] The block identification number can be configured to include, for example, at least information indicating partial irradiation, information regarding the shape of the pattern, and information regarding the size of the pattern on the sample surface.

Further, a block recognition unit may be provided in the control unit of the charged particle beam exposure apparatus, and a block recognition number may be generated from information such as a graphic code, a pattern size, and a pattern position supplied from a pattern generator. .

Embodiment An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

In the present embodiment, information on the block pattern, such as the position of the block pattern in the area, the offset amount, etc., is stored in the block pattern data memory. In this case, the address of this information is managed by, for example, a 16-bit block identification number.

In addition, when a pattern similar to a block pattern can be formed by partially irradiating a charged particle beam such as a triangular pattern, a similar pattern whose size differs on the sample surface by, for example, 0.01 μm unit. A block identification number is assigned to the irradiation position of the charged particle beam that can form the image. That is, it is treated as if there is a separate block pattern at that position.

Therefore, the value of the mask differential deflection amount for generating a similar figure in 0.01 μm units on the sample surface is distinguished by each block identification number, and for example, a transmission area for recognizing each block and exposing accurately is provided. The amount, the dynamic mask differential amount, and the like are obtained, and these are stored in the memory in a subordinate relation to each block identification number. The stored data is corrected by a correction coefficient obtained by mask calibration, and then sent to a block pattern correction unit.

Here, the exposure data is stored as a block identification number, an arrangement position, and an arrangement number for a repetitive figure, and is stored as a figure code, a pattern size, and a pattern position for other patterns.

Therefore, in the present embodiment, it is natural that block exposure is performed for a repetitive figure, and, among other patterns, a figure that can be obtained in a desired shape by partially irradiating a charged particle beam such as a triangle is partially exposed. Block pattern exposure by irradiation is performed, and other patterns are exposed in a variable rectangle.

Therefore, in this embodiment, a block recognition unit is provided, and for a figure that can be obtained in a desired shape by partially irradiating a charged particle beam such as a triangle, the figure code supplied from the pattern generator and the size of the pattern are used. , Supplying the information of the position of the pattern to the block recognition unit,
From these, a block identification number including information on partial irradiation, information on the shape of the pattern, and information on the size of the pattern on the sample surface is generated, and the block is recognized and selected based on the block identification number. To allow exposure.

Such a block identification number is represented by a 16-bit digital signal, for example, as shown in FIG.

Here, the 13th to 15th bits are control bits. In particular, when the 13th and 14th bits are [00], they are variable rectangles, and when they are [01], they are X-axis variable (the charged particle beam is Deflected to partially illuminate), in the case of [10], the Y-axis is variable (partially illuminated by deflecting the charged particle beam in the Y-axis direction), and in the case of [11], there is no variation (the entire surface is exposed). That means).

The 15th bit is a bit that indicates whether the charged particle beam can be changed from left, right, up, or down when performing X axis variable or Y axis variable, and [0] is the X axis variable. In this case, variable from the left side, variable in the Y axis, variable from the upper side, [1] means variable in the X axis, variable from the right side, and variable in the Y axis, variable from the lower side.

The twelfth bit is a bit for identifying a pattern, for example, a triangle code and another graphic code. For example, [1] is set for a standard angle triangle and an arbitrary angle triangle, and In the case of the figure, [0] is set.

The ninth to eleventh bits are for displaying a pattern code in the case of a triangle code. For example, when a pattern code of a standard triangular triangle is registered as shown in FIG. , [000] for pattern code "2", [001] for pattern code "3", [010] for pattern code "4", [011] for pattern code "5", any In the case of an angular triangle, a registered pattern code is set.

The 0th to 8th bits are bits for indicating the beam size, and indicate the size in the X-axis or Y-axis direction, that is, the value of X2 or Y2, so that the LSB becomes 0.01 μm. . Therefore, for example, when X2 = 1.5 μm, [0
10010110], and when X2 = 3.2 μm, [10100
0000] is displayed.

So, for example, if the location on the exposure data is
3, X1, Y1, 1.5, 1.5 [Graphic code, exposure position X, exposure position Y, size in X-axis direction, size in Y-axis direction] In the case of an exposure pattern, the figure code is 3, Is 1.5, the block recognition unit generates a 16-bit code [xxx1001010010110] as the block recognition number. Therefore, block exposure can be performed also on the exposure data indicated by the conventional location.

In the case of partial irradiation, it is a matter of course that the exposure data may be created using the block identification number from the beginning.

According to this embodiment, when the charged particle beam is partially irradiated on the block pattern, the charged particle beam is partially irradiated on the block pattern by deflection by the mask deflecting unit, as in the case of performing the entire surface exposure. Therefore, such partial irradiation can be easily performed.

In the above-described embodiment, a case has been described in which a block pattern capable of forming a similar pattern by partially irradiating a charged particle beam, for example, a case of partially irradiating a triangular block pattern is described. The present invention can be widely applied to the case where partial irradiation is performed on a block pattern having a shape.

[Effects of the Invention] According to the present invention, the irradiation area of the charged particle beam when the charged particle beam formed into a polygon by the polygon forming plate is partially irradiated to the block pattern is also treated as one block. A block identification number is given to distinguish the value of the deflection amount when the charged particle beam is partially irradiated on the block pattern, and the charged particle beam is blocked even when the charged particle beam is partially irradiated on the block pattern. As in the case of irradiating the entire pattern, the method of deflecting the charged particle beam based on the block identification number using the deflector for selecting a block pattern is adopted, so that such partial irradiation can be easily performed. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a block identification number in one embodiment of the present invention, FIG. 2 is a diagram showing an example of a pattern code, and FIG. 3 is a diagram showing a main part of an example of a conventional electron beam exposure apparatus. FIG. 4, FIG. 4 is a plan view showing a block mask used in the conventional example of FIG. 3, FIG. 5 is a plan view showing one area of the block mask of the example of FIG. 4, and FIG. FIG. 7 is a view showing a method of forming a variable rectangle in the conventional electron beam exposure apparatus, and FIG. 7 is a view showing a method of forming a variable triangle in the conventional electron beam exposure apparatus of FIG.

Claims (4)

(57) [Claims] 1. A polygon forming plate having a polygonal transmission pattern formed on an optical axis, a block mask having a plurality of block patterns formed thereon, and a block pattern selection for selecting the block pattern. After arranging a deflector for, after forming the charged particle beam generated from the charged particle beam source into a polygon by the polygon forming plate,
Further, in the charged particle beam exposure method of irradiating the selected one of the plurality of block patterns entirely or partially to form a desired pattern and exposing the sample, the charged particles The irradiation area of the charged particle beam when the beam is partially irradiated on the block pattern is treated as one block, and the value of the amount of polarization when the charged particle beam is partially irradiated on the block pattern is distinguished. To give the block identification number,
When partially irradiating the charged particle beam to the block pattern, the charged particle beam is deflected using the block pattern selecting deflector based on the block identification number. Method. 2. The charged particle beam exposure method according to claim 1, wherein the block pattern to be subjected to the partial irradiation is a block pattern having a shape capable of forming a pattern similar to the block pattern by the partial irradiation. 3. The apparatus according to claim 1, wherein the block identification number includes at least information on partial irradiation, information on a pattern shape, and information on a size of the pattern on the sample surface. Or the charged particle beam exposure method according to 2. 4. The apparatus according to claim 1, further comprising a block recognizing unit for generating the block recognizing number from information such as a graphic code, a pattern size, and a pattern position supplied from a pattern generator. 3. The charged particle beam exposure method according to 3.