JP2007019245A - Charged particle beam exposure apparatus and device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged particle beam exposure for preventing an entire blanking aperture array from becoming unusable as a defective product even when a defect occurs in any blanking electrode of a blanking aperture array composed of a plurality of blanking electrodes. An apparatus and a device manufacturing method using the charged particle beam exposure apparatus are provided.
Drawing blanking is performed such that when at least one drawing blanking electrode does not operate, an area to be drawn by at least one drawing blanking electrode is drawn instead of at least one drawing blanking electrode. Since the blanking aperture array has relief blanking electrodes arranged adjacent to both sides of the electrode, the entire blanking aperture array is not usable, and should be used as a blanking aperture array that performs normal operation. Can improve yield significantly.
[Selection] Figure 4

Description

  The present invention relates to a charged particle beam exposure apparatus such as an electron beam exposure apparatus, an ion beam exposure apparatus used for exposure of a semiconductor integrated circuit or the like, and a focused ion beam apparatus used for processing, and more particularly using a plurality of charged particle beams. The present invention relates to a charged particle beam exposure apparatus for performing pattern drawing and a device manufacturing method using the charged particle beam exposure apparatus.

Conventionally, with respect to electron beam drawing technology in the manufacture of semiconductor devices, for example, Press Journal Co., Ltd., issued February 20, 1988, Monthly Semiconductor World (Semiconductor World) March, P75-P83, (non-patent literature) 1) and Industrial Research Co., Ltd., issued on March 1, 1988, “Electronic Materials March 1988 Issue, P43 to P50 (Non-patent Document 2). Non-patent Document 1 and As described in Non-Patent Document 2, as a representative example of this type of electron beam drawing technique, a drawing method based on a raster scan method using a single spot beam is generally well known.
Further, as a multi-charged particle beam exposure apparatus using a plurality of charged particle beams, for example, a large number of openings are disclosed in Japanese Utility Model Publication No. 56-19402 (Patent Document 1) and Applied Physics 69, 1135 (1994) (Non-Patent Document 3). A blanking aperture array method is described.
In Japanese Utility Model Publication No. 56-19402 (Patent Document 1), a blanking aperture array is formed by using a semiconductor crystal such as silicon as a substrate and forming a plurality of openings in a two-dimensional arrangement at predetermined intervals. A pair of blanking electrodes are formed on the opposing side surfaces of the two, and whether or not a voltage is applied between the blanking electrodes is controlled by pattern data. For example, if one electrode of the blanking electrode in each opening is grounded and a voltage is applied to the other electrode, the electron beam passing through this opening is bent, so after passing through the lens installed in the lower part, the single opening The electron beam is cut by the aperture and does not reach the sample surface (resist layer on the semiconductor substrate).

On the other hand, if a voltage is not applied to the other electrode, the electron beam passing therethrough is not bent, so that the electron beam reaches the sample surface without being cut by the aperture after passing through the lens disposed below. However, in this case, if the voltage is no longer applied to the blanking electrode for some reason, the sample is always irradiated with the beam, causing a problem.
In order to avoid this, a method shown in Japanese Patent Application No. 2003-348354 has been proposed as a method for controlling charged particle beams. A plurality of second deflection means and a first deflection means are provided separately from the second deflection means, and when a voltage or current is applied to the second deflection means, the sample is irradiated with a charged particle beam. In order to irradiate the charged particle beam to the shielding plate when it is not applied, the deflection signal is always applied to the first deflection unit, and when the signal is applied to the second deflection unit, the charged particle beam is applied to the sample. Designed to reach. This is because the charged particle beam does not reach the sample and is shielded by the shielding plate even when any of the plurality of second deflecting means arranged fails. In other words, a method has been proposed that does not have a problem that the sample is always irradiated with the beam even when the voltage is no longer applied to the blanking electrode for some reason.

Here, a conventional drawing method using a charged particle beam exposure apparatus that performs pattern drawing using a blanking aperture array having a large number of openings will be described with reference to FIGS.
As shown in FIG. 1, a plurality of electron beams 10 that have passed through a blanking aperture array 6 having a large number of openings are collectively raster scanned.
FIGS. 2A and 2B are schematic diagrams showing the positions of 4 × 4 blanking electrodes, which are part of the blanking aperture array 6, and the area where each blanking electrode is drawn on the sample 11. A figure is shown.
As shown in FIG. 2A, the electron beam 10 that has passed through one blanking electrode 201 raster scans a rectangular region 201-a region surrounded by a dotted line on the sample 11. The beam that has passed through the adjacent blanking electrode 202 performs a raster scan on a rectangular region 202-A surrounded by a dotted line on the sample 11. Each drawing region such as the blanking electrodes 201 and 202 is controlled so that adjacent regions are aligned and connected. Based on a signal generated by a pattern generator (not shown), each blanking electrode 201, 202, etc. is turned on and off, and writing is performed in each drawing area by a plurality of electron beams 10 for raster scanning. The entire pattern is drawn by connecting the patterns of the individual areas.
Japanese Utility Model Publication No. 56-19402 Press Journal Co., Ltd., issued February 20, 1988, Monthly Semiconductor World (Semiconductor World) March issue, P75-P83 Industrial Research Co., Ltd., issued March 1, 1988, "Electronic Materials March 1988 Issue, P43-P50" Applied Physics 69, 1135 (1994)

However, in the charged particle beam exposure apparatus that performs pattern drawing using the blanking aperture array 6 having a large number of openings shown in FIGS. 1 and 2A, a large number of blanking electrodes 201 constituting the blanking aperture array 6 are used. , 202, etc., for example, as shown in FIG. 2B, if the blanking electrode 202 becomes defective, the pattern drawing by the electron beam 10 in the rectangular region 202-a becomes defective. breaking bad.
As a result, the blanking aperture array 6 is a defective product and cannot be used for drawing, and the blanking aperture array 6 itself needs to be replaced.
Thus, in the blanking aperture array 6 composed of a plurality of blanking electrodes 201, 202, etc., even if only one blanking electrode 202 is defective, it is not allowed and a yield of 100% is required.
Therefore, the present invention prevents the entire blanking aperture array from becoming unusable as a defective product even if any blanking electrode of the blanking aperture array composed of a plurality of blanking electrodes is defective. It is an object to provide a particle beam exposure apparatus and a device manufacturing method using the charged particle beam exposure apparatus.

In order to achieve the above object, a charged particle beam exposure apparatus of the present invention comprises a charged particle beam source for irradiating a charged particle beam and a blanking aperture array having a plurality of openings composed of a plurality of drawing blanking electrodes. A first deflecting means for deflecting each of the charged particle beams; and at least above, below or on the same plane of the first deflecting means, deflecting each of the charged particle beams in a lump, and drawing When the blanking electrode is operated, the sample is irradiated with the electron beam. When at least one drawing blanking electrode is not operated, the electron beam passing through the at least one drawing blanking electrode is used as a shielding plate. A charged particle beam exposure apparatus including: a second deflecting unit configured to irradiate with the first deflecting unit. Adjacent to both sides of the drawing blanking electrode so that the area where the at least one drawing blanking electrode should be drawn instead of the at least one drawing blanking electrode when the king electrode does not operate The blanking aperture array has a relief blanking electrode disposed therein.
Furthermore, the device manufacturing method of the present invention comprises a step of exposing the exposure target using the charged particle beam exposure apparatus, and a step of developing the exposed exposure target.

According to the charged particle beam exposure apparatus of the present invention, when at least one drawing blanking electrode does not operate, an area to be drawn by at least one drawing blanking electrode is used instead of at least one drawing blanking electrode. The blanking aperture array has relief blanking electrodes disposed adjacent to both sides of the drawing blanking electrode so as to draw.
For this reason, when an operation failure occurs in any of the drawing blanking electrodes for some reason, drawing is performed by two relief blanking electrodes adjacent to both sides of the drawing blanking electrode in which the operation failure occurs, and the operation The drawing area shared by the defective drawing blanking electrode is also drawn normally, the entire blanking aperture array is not usable, and it can be used as a blanking aperture array for normal operation, and yield is improved. Improve dramatically.
Further, according to the device manufacturing method of the present invention, when an operation failure occurs in any of the drawing blanking electrodes for any reason, two reliefs adjacent to both sides of the drawing blanking electrode in which the operation failure occurs. A blanking aperture array that draws with a blanking electrode for normal operation and draws normally even in a drawing area shared by the blanking electrode for defective drawing, and the blanking aperture array does not become unusable and operates normally. In order to dramatically improve the yield, the manufacturing efficiency of the semiconductor device is also improved.

  Hereinafter, the present invention will be described based on the embodiments with reference to the drawings.

A multi-electron beam exposure apparatus, which is a charged particle beam apparatus according to a first embodiment of the present invention, will be described with reference to a schematic diagram of a main part of FIG.
The present invention is not limited to the electron beam and can be similarly applied to an exposure apparatus using an ion beam, and the same effect can be obtained.
An electron beam 10, which is a charged particle beam emitted radially from the electron source 1, is formed into an area beam having a desired size by the collimator lens 2, and then enters the mask 3 almost perpendicularly. The mask 3 is a mask having a plurality of patterns. The electron beams 10 formed through the mask 3 are each converged by the lens 4 onto the blanking aperture array 6. The blanking aperture array 6 is composed of an array of a plurality of drawing blanking electrodes, and deflects each electron beam 10. An electrostatic deflector 5 is disposed directly below the blanking aperture array 6 and deflects all the electron beams 10 simultaneously. The electron beam 10 deflected by the blanking aperture array 6 and the deflector 5 is shielded by the blanking diaphragm 9, and the beam not deflected by the blanking aperture array 6 and the deflector 5 is converged by the lenses 7 and 8, and then the sample 11 is irradiated.

When the electron beam 10 is turned on / off by using only the blanking aperture array 6 without using the deflector 5, the drawing blanking electrodes constituting the blanking aperture array 6 as shown in FIG. When a voltage is applied to 6-1 and 6-2, the blanking diaphragm 9 is irradiated with the electron beam 10, and when no voltage is applied, the sample 11 is irradiated with the electron beam 10.
However, the blanking aperture array 6 is an array of deflectors composed of a plurality of drawing blanking electrodes 6-1 and 6-2. As shown in FIG. When the drawing blanking electrode 6-2 also fails, the electron beam 10 is always irradiated onto the sample 11.
Therefore, if the deflector 5 positioned above or below the blanking aperture array 6 is used as shown in FIG. 5C or FIG. When the drawing blanking electrodes 6-1 and 6-2 constituting the ranking aperture array 6 are in operation, the electron beam 10 is irradiated to the sample 11, and the drawing blanking electrode 6-2 is operated. If not, the blanking stop 9 is irradiated with the electron beam 10.
That is, when any of the drawing blanking electrodes 6-1 and 6-2 constituting the blanking aperture array 6 fails, the electron beam 10 is not irradiated on the sample 11.

Next, Embodiment 2 of the present invention will be described with reference to FIG.
The electron beam 10 maintains a vertical state with respect to the sample 11 above and below the blanking aperture array 6 to completely eliminate the axial deviation, and the aberration characteristics are not impaired by the operations of the deflector 5 and the blanking aperture array 6. The electrostatic deflector 5-1 and the deflector 5-2 may be disposed above and below the blanking aperture array 6.
The deflectors 5-1 and 5-2 are common to all the electron beams 10, and the blanking aperture array 6 is a deflector for deflecting the individual electron beams 10. The deflectors 5-1 and 5-2 have a function of deflecting the electron beam 10 to the right side, and the blanking aperture array 6 deflects the beam to the left side. The deflectors 5-1 and 5-2 are arranged symmetrically with respect to the blanking aperture array 6 in the horizontal direction.
In the above configuration, when only the deflectors 5-1 and 5-2 are operated, the electron beam 10 is irradiated to the blanking diaphragm 9, and when the blanking aperture array 6 is further operated, the electron beam 10 is irradiated. Is irradiated to the sample 11.
Accordingly, even when a part of the drawing blanking electrodes in the blanking aperture array 6 fails, such as the drawing blanking electrode 6-2 constituting the blanking aperture array 6, the electron beam 10 reaches the sample 11. Without being blocked by the blanking diaphragm 9, the electron beam 10 maintains a vertical state with respect to the sample 11 above and below the deflector 5 and the blanking aperture array 6, and does not cause an axis deviation, leading to deterioration of beam characteristics. There is no.
Although the deflectors 5, 5-1, 5-2 and the blanking aperture array 6 have been described using an electrostatic type example, the same effect can be obtained even if an electromagnetic type deflector is used.
In the above embodiment, the deflectors 5-1 and 5-2 are arranged at positions symmetrical with respect to the blanking aperture array 6. A similar effect can be obtained by adjusting the deflection sensitivity and the positional relationship of the ranking aperture array 6.

Next, Embodiment 3 of the present invention will be described with reference to FIG.
The deflector 5 is an electromagnetic deflector, the blanking aperture array 6 composed of the drawing blanking electrodes 6-1 and 6-2 is an electrostatic deflector, and the deflection center for each beam of the deflector 5 and the blanking aperture array 6 is They may be arranged on the same plane so that they coincide with each other, and the deflection sensitivities of the deflector 5 and the blanking aperture array 6 are the same and the directions are opposite.
In this case, the electron beam 10 is deflected when only the deflector 5 is operating, and the electron beam 10 is not deflected when the deflector 5 and the blanking aperture array 6 are operating. When the blanking aperture array 6 is operated at all times, the sample 11 can be irradiated with the electron beam 10.
For this reason, even if a part of the blanking aperture array 6 fails, such as the drawing blanking electrode 6-2 constituting the blanking aperture array 6, the electron beam 10 is not always irradiated to the sample 11.
Further, since the deflecting positions of the deflector 5 and the blanking aperture array 6 are the same, the electron beam 10 is maintained perpendicular to the sample 11 not only at the top and bottom of the deflector 5 and the blanking aperture array 6. As a result, the axis of the electron beam 10 is not displaced.
As described above, the electron beam exposure apparatus shown in FIG. 1 always keeps the electron beam 10 deflected using the deflectors 5, 5-1, and 5-2, and the blanking aperture array 6 is The electron beam 10 is irradiated even when the sample 11 is irradiated with the beam only when it is operating, and any of the drawing blanking electrodes 6-1 and 6-2 constituting the blanking aperture array 6 fails. Is not irradiated on the sample 11.

The blanking aperture array 6 having a large number of openings is composed of a plurality of blanking electrodes for drawing composed of n × m columns.
FIG. 3 schematically shows an arrangement of 3 × 3 rows of drawing blanking electrodes 301, 302, and 303. Blanking electrodes 300 ′, 301 ′, and 302 ′ constituting the relief blanking aperture 6 are disposed on both sides of the drawing blanking electrodes 301, 302, and 303. The structure, configuration, dimensions, and arrangement of the relief blanking electrodes 300 ′, 301 ′, and 302 ′ are the same as those of the drawing blanking electrodes 301, 302, and 303.
A rectangular area surrounded by dotted lines indicated as C, D, G, and H represents one drawing area 302-a in which a beam that has passed through one blanking electrode 302 is drawn by raster scanning. A rectangular area surrounded by a dotted line adjacent to the area 302-A represents an area drawn by the adjacent drawing blanking electrodes 301, 302, and 303.
In this way, the drawing regions of the drawing blanking electrodes 301, 302, and 303 are controlled so as to be aligned and connected to the adjacent regions. Based on a signal generated by a pattern generator (not shown), each drawing blanking electrode 301, 302, 303 is turned on and off, and writing is performed in each drawing area by a plurality of raster beams. Is made. As a result, the patterns of the individual areas are connected to draw the entire pattern.

FIG. 4 illustrates a drawing method according to the first embodiment of the present invention when one blanking electrode 302a in the blanking aperture array 6 having a large number of openings becomes defective for some reason.
The drawing blanking electrode 302a draws the rectangular region CDGH. However, suppose that for some reason it is not possible to blank and the area cannot be drawn. In that case, drawing is performed using two relief blanking electrodes 301′a and 302′a adjacent to the drawing blanking electrode 302a.
The relief blanking electrode 301′a can draw the entire rectangular area indicated by ABEF by raster scanning in the direction indicated by arrow α, but draws only the area of CDEF that cannot be drawn due to a defect. In the ABCD area, a signal is generated by a pattern generator (not shown) or controlled by another control means (not shown) so that the electron beam 10 is always turned off.
On the other hand, in the CDEF region, the relief blanking electrode 301′a is turned on and off by a normal pattern signal generated by the pattern generator, and a normal pattern is drawn.
At the same time, the other relief blanking electrode 302′a can draw the entire rectangular area indicated by EFIJ by the raster scan in the direction indicated by the arrow α, but draws only the EFGH area that cannot be drawn due to a defect. The GHIJ region is generated by a signal from a pattern generator (not shown) or controlled by other control means (not shown) so that the electron beam 10 is always turned off.
On the other hand, in the EFGH region, the relief blanking electrode 302′a is turned ON / OFF by a signal based on the normal pattern signal generated by the pattern generator, and a normal pattern is drawn.
Although not shown, the drawing and relief blanking electrodes are connected to each other so that they can be driven by voltage or current, and the wiring is used for each drawing based on signals generated by the pattern generator and other control signals. In addition, the relief blanking electrode is wired and electrically controlled so that it can be turned on and off. Even if the direction of the raster scan is a direction rotated 90 degrees with respect to the direction shown in FIG. 4, the method according to the present embodiment is possible without any problem.

3 and 4 show examples in which the arrangement of the drawing blanking electrodes is set at substantially equal intervals in the X and Y directions, and the relief blanking electrodes are arranged therebetween. Accordingly, the embodiment has been shown in which the interval between the drawing blanking electrode array and the relief blanking electrode array is halved.
However, the arrangement of the blanking electrodes for drawing may be set such that the spacing ratio in the X direction and the Y direction is 2: 1, and the relief blanking electrode rows are arranged between the wide spacings. Thus, the drawing blanking electrodes and the relief blanking electrodes are arranged at equal intervals in the X direction and the Y direction. However, in this case, the ratio of the width in the X direction and the Y direction of the drawing region by one blanking electrode is 2: 1 and becomes a rectangle. The aspect ratio of the raster scan can be adjusted to this and there is no problem.

Next, as Example 4 of the present invention, a semiconductor device manufacturing process using the charged particle beam exposure apparatus of Example 1 will be described.
FIG. 8 is a diagram showing a flow of an entire manufacturing process of a semiconductor device.
In step 1 (circuit design), a semiconductor device circuit is designed.
In step 2 (EB data conversion), exposure control data for the exposure apparatus is created based on the designed circuit pattern.
On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer using lithography using the exposure apparatus and wafer to which the exposure control data has been input. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes, and is shipped in Step 7.
The wafer process in step 4 includes the following steps. An oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, an electrode formation step for forming electrodes on the wafer by vapor deposition, an ion implantation step for implanting ions on the wafer, and applying a photosensitive agent to the wafer The resist processing step, the exposure step for printing and exposing the circuit pattern onto the wafer after the resist processing step by the above-described exposure apparatus, the development step for developing the wafer exposed in the exposure step, and the etching for removing portions other than the resist image developed in the development step Step, resist stripping step to remove resist that is no longer needed after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

It is a principal part schematic diagram of the charged particle beam exposure apparatus of a prior art example and the Example of this invention. It is a block diagram of the blanking aperture array which comprises the charged particle beam exposure apparatus of a prior art example. It is a block diagram of the blanking aperture array which comprises the charged particle beam exposure apparatus of Example 1 of this invention. It is a block diagram of the blanking aperture array which comprises the charged particle beam exposure apparatus of Example 1 of this invention. It is a block diagram of the deflection | deviation effect | action by the 1st deflection | deviation means and 2nd deflection | deviation means which comprise the charged particle beam exposure apparatus of a prior art example and Example 1 of this invention. It is a block diagram of the deflection | deviation effect | action by the 1st deflection | deviation means and 2nd deflection | deviation means which comprise the charged particle beam exposure apparatus of Example 2 of this invention. It is a block diagram of the deflection | deviation effect | action by the 1st deflection | deviation means and 2nd deflection | deviation means which comprise the charged particle beam exposure apparatus of Example 3 of this invention. It is a figure which shows the flow of the whole manufacturing process of the semiconductor device of Example 4 of this invention using the charged particle beam exposure apparatus of Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electron source 2 Collimator lens 3 Mask 4 Lens array 5, 5-1, 5-2 Deflector 6 Blanking aperture array
6-1, 6-2 Blanking electrode for drawing
7, 8 Lens 9 Blanking stop 10 Beam 11 Sample 201, 301, 302, 303 Blanking electrode for drawing 300 ', 301', 302 'Blanking electrode for relief

Claims (2)

A charged particle beam source for irradiating a charged particle beam;
A first deflection means comprising a blanking aperture array having a plurality of openings made of a plurality of drawing blanking electrodes, and deflecting each of the charged particle beams;
Provided at least above, below or on the same plane as the first deflection means, deflects each charged particle beam in a lump, and irradiates the sample with the electron beam when the drawing blanking electrode is operated. A second deflecting means for irradiating the shielding plate with the electron beam passing through the at least one drawing blanking electrode together with the first deflecting means when at least one of the drawing blanking electrodes does not operate; In a charged particle beam exposure apparatus having
The drawing blanking so as to draw a region to be drawn by the at least one drawing blanking electrode instead of the at least one drawing blanking electrode when the at least one drawing blanking electrode does not operate. The charged particle beam exposure apparatus, wherein the blanking aperture array has a relief blanking electrode disposed adjacent to both sides of the electrode.   A device manufacturing method comprising: a step of exposing an exposure target using the charged particle beam exposure apparatus according to claim 1; and a step of developing the exposed exposure target.

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