JP2008041891A - Exposure apparatus, and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus and a device manufacturing method whose throughput is made high when deflecting a charged beam having a wide area by its deflector. <P>SOLUTION: In the exposure apparatus, a plurality of charged beams are subjected to the accelerating, focusing, and deflecting actions performed by a reduction optical system to irradiate a sample with the beams. The apparatus has an electrostatic deflector for generating an electric field which has a pair of electrodes provided oppositely to each other inside or just under the reduction optical system positioned just above the sample. Further, the exposure apparatus has a magnetic-field deflector for generating a magnetic field which has such a pair of coils provided oppositely to each other inside or just under the reduction optical system positioned just above the sample as to interpose the pair of electrodes between them. Moreover, the plurality of charged beams pass between the pair of electrodes. Furthermore, the electrostatic deflector and the magnetic-field deflector are so provided that the direction of the plurality of charged beams being arranged, the direction of the electric field, and the direction of the magnetic field overlap with each other in parallel with each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exposure apparatus and a device manufacturing method using a charged beam such as electrons and ions.

In recent years, miniaturization of LSI patterns has progressed. For example, in the world of DRAMs, device integration plans of 1G, 4G, and 16G have been advanced even after the development of 256M.
Among them, the exposure technique is considered to be an extremely important technique among the fine processing techniques. In particular, the charged beam drawing technique is capable of fine processing of 0.1 μm or less, and is one of the future exposure means. It is expected as one.
Conventionally, a charged beam exposure apparatus used is a single beam drawing method of a Gaussian beam method and a variable shaped beam method.
Since this conventional example has low productivity, it has been used for mask drawing, research and development of VLSI, and application fields to low-volume ASIC devices.
Recently, research and development of charged beam technology has progressed, and a charged beam drawing method that can improve the productivity of a charged beam exposure apparatus and can be used for the production of memory devices such as DRAM has been proposed and researched.
This charged beam drawing method is a method for improving the drawing speed by using a plurality of charged beams.
In order to obtain a throughput of 30 to 40 wafers / hour or more required for semiconductor device production by this charged beam drawing method, several thousand or more beams are required as the number of charged beams.
For this reason, a technology for forming a multi-lens having a high arrangement density by downsizing an electron lens is important.

These multi-electron exposure apparatuses will be described with reference to FIG.
The electron gun 100, the irradiation lens system 110, the charged beam forming unit 120, the lenses 131 and 132 of the reduction optical system 130, and the stage 140 are included.
The electron gun 100 includes a three-electron electron gun including a thermionic source 101 such as LaB6, a Wehnelt electrode 102, and an anode electrode 103.
The charged beam 1 emitted from the electron source 101 forms a close-over, is accelerated to 50 kV, and enters the irradiation lens 111.
Therefore, the charged beam is made substantially parallel and enters the charged beam forming unit 120.
The charged beam forming unit 102 includes an aperture array 121 for dividing a charged beam emitted from a single light source into charged beams, and a multi-lens array 122 having a function of converging each of the divided charged beams. The
Further, the charged beam forming unit 102 includes a BLA (blanking array) 123 that performs beam blanking by independently deflecting the charged beam, and a beam shielding electrode 124 that blocks the blanked beam.
Next, the charged beam exiting the charged beam forming unit 120 is incident on the lower reduction optical system 130.
Next, the charged beam projects a secondary light source image of the charged beam formed by the lens array 122 onto the sample 141 electrostatically adsorbed on the stage 140 by a doublet type lens including the lenses 131 and 132.
In drawing using a charged beam, the charged beam is simultaneously scanned using the deflector 10 provided in the reduction optical system 130.
Then, in synchronization with this scanning, the BLA 123 turns on / off the beam so that an arbitrary pattern is exposed on the sample 141 coated with a photosensitive agent.
In such a system, as a deflector for moving the position of the charged beam, Japanese Patent Application Laid-Open No. 2005-50888 (Patent Document 1) or the like is used. Multipolar deflectors such as poles have been proposed.
Japanese Patent Laid-Open No. 2005-50888

When a charged beam with a large area is deflected using a conventional charged beam deflector, the surrounding beam is distorted, so there is a limit to the increase in size, and the high-throughput charged beam exposure system exceeds the performance of the conventional method. It was difficult to realize.
Accordingly, an object of the present invention is to provide an exposure apparatus and a device manufacturing method with high throughput when a charged beam having a large area is deflected by a deflector.

In order to solve the above problems, an exposure apparatus according to the present invention is an exposure apparatus in which a plurality of charged beams are irradiated on a sample by being subjected to acceleration, convergence, and deflection by a reduction optical system.
An electrostatic deflector which has a pair of electrodes facing each other inside or directly below the reduction optical system located immediately above the sample and generates an electric field;
A magnetic deflector that generates a magnetic field, and has a pair of coils that are opposed to each other with the pair of electrodes sandwiched inside or directly below the reduction optical system located immediately above the sample;
The electrostatic deflector and the magnetic field deflection so that the plurality of charged beams pass between the pair of electrodes, and the direction in which the plurality of charged beams are arranged, the direction of the electric field, and the magnetic field overlap in parallel. A vessel is provided.
Further, the exposure apparatus of the present invention is configured such that scanning signals of the electrostatic deflector and the magnetic deflector are synchronized with the movement of the sample, and the plurality of charged beams are individually turned on / off based on graphic information. Features.
Furthermore, the device manufacturing method of the present invention includes a step of exposing a wafer using the exposure apparatus,
And a step of developing the wafer.

According to the exposure apparatus of the present invention, an electrostatic deflector and a plurality of charged beams pass between a pair of electrodes so that a direction in which the plurality of charged beams are arranged, an electric field direction, and a magnetic field overlap in parallel. A magnetic deflector is provided.
Therefore, the charged beam or ion beam can be deflected in the plane, and a large area can be drawn with little deflection distortion.
The length of the charged beam arrangement is not limited, and an exposure apparatus such as a charged beam exposure apparatus, a charged beam microscope apparatus, a processing apparatus, or an inspection apparatus with high throughput can be realized.
Furthermore, the exposure apparatus of the present invention increases the throughput of the exposure apparatus by synchronizing the scanning signals of the electrostatic deflector and the magnetic field deflector with the sample movement, and individually turning on and off the charged beam based on the graphic information. I can do it.

  Hereinafter, a charged beam exposure apparatus of the present invention will be described with reference to the drawings.

The exposure apparatus of the present invention will be described with reference to FIGS.
In the charged beam exposure apparatus of the present invention shown in FIG. 7, a plurality of charged beams 2 are irradiated on the sample 141 by being accelerated, converged and deflected by the reduction optical system 130.
The electrostatic deflector 3 includes a pair of electrodes 3a and 3a provided facing each other inside or directly below the reduction optical system 130 positioned immediately above the sample 141, and generates an electric field.
The magnetic deflector 4 has a pair of coils 4a and 4a that are provided facing each other with the pair of electrodes 3a and 3a sandwiched inward inside or directly below the reduction optical system 130 positioned immediately above the sample 141, and generates a magnetic field. To do.
The pair of electrodes of the electrostatic deflector 3 is arranged such that the plurality of charged beams 2 pass between the pair of electrodes 3a, 3a, and the direction in which the plurality of charged beams 2 are arranged, the direction of the electric field, and the magnetic field overlap in parallel. 3a, 3a and a pair of coils 4a, 4a of the magnetic deflector 4 are provided.
The charged beam 2 is emitted from the charged beam generator 1 and irradiated onto the sample 141 placed on the continuously moving stage 140.
At this time, the charged beam 2 emitted from the charged beam generator 1 is between the electrodes 3a and 3a of the electrostatic deflector and the coils 4a and 4a of the magnetic deflector 4 placed substantially parallel to the arrangement direction of the charged beam 2. Pass through.

Next, the deflection operation of the charged beam 2 using the electrostatic deflector 3 and the magnetic deflector 4 in which the electric field and the magnetic field are superimposed in parallel will be described with reference to the side view of FIG.
The directions of the electric field and magnetic field generated by the electrostatic deflector 3 and the magnetic deflector 4 are generated in the vertical direction in FIG.
Thus, when the charged beam 2 passes between the electrodes 3a and 3a of the electrostatic deflector 3 and the coils 4a and 4a of the magnetic deflector 4, the electrodes 3a and 3a of the electrostatic deflector 3 act. In the electric field to be deflected in the X direction.
On the other hand, since the magnetic field applied by the coils 4a and 4a of the magnetic field deflector 4 is deflected in the Y direction, the deflection component can be obtained by superimposing the electrostatic deflector 3 and the magnetic field deflector 4 arranged in parallel. Can be orthogonal.

FIG. 3 is a cross-sectional view of the electrostatic deflector 3 and the magnetic deflector 4, in which the charged beams 2 are arranged in the Y direction.
Here, the charged beams 2 are arranged at equal intervals. By operating the coils 4 a and 4 a of the magnetic deflector 4, the charged beam 2 is deflected in the Y direction, and the charged beam 2 can be irradiated while filling the space between the charged beams 2.
On the other hand, by operating the electrodes 3 a and 3 a of the electrostatic deflector 3, the beam is deflected in the X direction that is the arrangement direction of the charged beam 2.
In this way, by operating the electrodes 3a, 3a of the electrostatic deflector 3 and the coils 4a, 4a of the magnetic deflector 4, the charged beam 2 can be freely moved in the plane.
Further, the scanning signals of the electrostatic deflector 3 and the magnetic deflector 4 are synchronized with the movement of the sample 141, and the plurality of charged beams 2 are individually turned on / off based on the graphic information.
Therefore, by causing the charged beam 2 to follow the deflection operation of the electrostatic deflector 3 in synchronization with the movement of the stage 140 shown in FIG. 1, it is possible to realize charged beam drawing in which the stage 140 is continuously moved.

FIG. 4 shows another embodiment in which drawing is performed by the drawing method of the present invention, in which the array 7 of the charged beams 2 on the sample 141 is a staggered array.
The charged beam 2 is deflected by the magnetic deflector 4 in the Y direction of each of the linear arrays a, b, and c and drawn.
Further, the space between the lines in the X direction of the line-shaped arrays a, b, c is deflected by the electrostatic deflector 3, so that the two-dimensionally using the discrete charged beam 2 as shown in the deflection drawing array 7 is used. This area can be drawn.
As described above, a large area is drawn using the electrostatic deflector 3 and the magnetic deflector 4 with a small deflection distortion, thereby limiting the length of the array of the charged beams 2 that has been limited in terms of accuracy. Therefore, a high-throughput charged beam exposure apparatus is realized.
The method of the present invention can be applied not only to a charged beam exposure apparatus, but also to an exposure apparatus such as a charged beam irradiation apparatus that irradiates a wide area with a charged beam or an ion beam, or a sample observation, processing, or inspection apparatus.

Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described with reference to FIGS.
FIG. 5 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, etc.).
Here, a semiconductor chip manufacturing method will be described as an example.
In step S1 (circuit design), a semiconductor device circuit is designed.
In step S2 (mask production), a mask is produced based on the designed circuit pattern.
In step S3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step S4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by using the mask and the wafer by the above-described exposure apparatus using the lithography technique.
Step S5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer manufactured in step S4.
This step S5 includes assembly processes such as assembly process (dicing, bonding), packaging process (chip encapsulation) and the like.
In step S6 (inspection), inspections such as an operation check test and a durability test of the semiconductor device manufactured in step S5 are performed.
Through these steps, the semiconductor device is completed and shipped (step S7).

FIG. 6 is a detailed flowchart of the process above Step 4.
In step S11 (oxidation), the surface of the wafer is oxidized.
In step S12 (CVD), an insulating film is formed on the surface of the wafer.
In step S14 (ion implantation), ions are implanted into the wafer.
In step S15 (resist process), a photosensitive agent is applied to the wafer.
In step S16 (exposure), the circuit pattern of the mask is exposed on the wafer by the exposure apparatus.
In step S17 (development), the exposed wafer is developed.
In step S18 (etching), portions other than the developed resist image are removed.
In step S19 (resist stripping), the resist that has become unnecessary after the etching is removed.
By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.

It is an exposure apparatus of Example 1 of this invention. It is a side view of the deflector of the exposure apparatus of Example 1 of this invention. It is sectional drawing of the deflector of the exposure apparatus of Example 1 of this invention. 1 is an exposure apparatus for charged beam drawing according to a first embodiment of the present invention. It is a flowchart for demonstrating manufacture of the device using the exposure apparatus of Example 1 of this invention. 6 is a detailed flowchart of the wafer process in Step 4 of the flowchart shown in FIG. 5. 1 is an overall configuration diagram of a correction optical system charged beam type exposure apparatus; FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Charged beam generation part 2 Charged beam 3 Electrostatic deflector 3a Electrode 4 Magnetic field deflector 4a Coil a. b. c. Line array 7 array
DESCRIPTION OF SYMBOLS 100 Electron gun 110 Irradiation system 120 Charge beam forming unit 121 Aperture array 122 Lens array 123 Blanker array 124 Shielding electrode 130 Reduction optical system 131, 132 Lens 140 Stage 141 Sample

Claims (3)

An exposure apparatus in which a plurality of charged beams are accelerated, converged and deflected by a reduction optical system and irradiated onto a sample.
An electrostatic deflector which has a pair of electrodes facing each other inside or directly below the reduction optical system located immediately above the sample and generates an electric field;
A magnetic deflector that generates a magnetic field, and has a pair of coils that are opposed to each other with the pair of electrodes sandwiched inside or directly below the reduction optical system located immediately above the sample;
The electrostatic deflector and the magnetic field deflection so that the plurality of charged beams pass between the pair of electrodes, and the direction in which the plurality of charged beams are arranged, the direction of the electric field, and the magnetic field overlap in parallel. An exposure apparatus characterized in that an exposure apparatus is provided.   2. The exposure according to claim 1, wherein scanning signals of the electrostatic deflector and the magnetic deflector are synchronized with movement of the sample, and the plurality of charged beams are individually turned on and off based on graphic information. apparatus A step of exposing a wafer using the exposure apparatus according to claim 1;
And a step of developing the wafer.

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