JP2804664B2 - Electrostatic adsorption mechanism of sample and electron beam lithography system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic adsorption mechanism for a sample and
About the electron beam lithography system.

[0002]

2. Description of the Related Art For example, in a semiconductor manufacturing process, when processing and inspecting a sample such as a workpiece or an inspection object formed of a semiconductor wafer, the sample is transferred to a sample transfer holder on a sample moving table (moving stage mechanism). Is mounted to move between a sample chamber for processing and inspection and a sample exchange chamber for exchanging samples.

Conventional sample transport holders include, for example, JP-A-59-67630, JP-A-59-29435,
As disclosed in JP-A-60-95931, JP-A-60-95932, etc., an electrode for electrostatic attraction and a dielectric (adsorption plate) are provided on a sample transfer holder, and the static electricity at the time of application of this electrode is provided. A reference block for positioning, fixing and holding the sample by using the electro-adsorption force, and for restricting the position of the sample cassette on the upper surface of the sample moving table as disclosed in JP-A-61-214517. A technology has been proposed in which a sample cassette is fixedly mounted by providing a dielectric (adsorption plate) having electrodes for electrostatic adsorption on the reference block.

[0004]

The technique utilizing this kind of electrostatic attraction force can simplify the mechanism as compared with a mechanical chuck mechanism or a vacuum attraction mechanism, and can place a sample on a sample transport holder. In the case of electrostatic attraction, it is evaluated as being able to correct the warpage of the sample.

In this type of conventional sample transfer holder, a mechanism for positioning, fixing and holding the sample is provided on the sample transfer holder side, while the sample transfer holder is positioned, fixed and held on the sample moving table. Since the mechanism was provided on the sample moving table side, there were the following problems in performing maintenance.

That is, if a mechanism for fixing and holding the sample transfer holder is provided on the sample transfer table, the sample transfer table is generally always in the sample chamber (the sample chamber is in a vacuum state during processing and inspection), and thus the sample transfer is performed. When performing maintenance of the holder fixing / holding mechanism, the vacuum of the sample chamber must be released to the atmospheric state, and the sample moving table must be taken out from the sample chamber where the holder is installed. As a result, a large amount of time is required to return the sample chamber to a vacuum again, and a large amount of time is required for maintenance work.

The present invention has been made in view of the above points, and has as its object to enable highly accurate positioning, fixing and holding of a sample while simplifying the mechanism of a sample transfer holder and a sample moving table, and to exchange a sample. The space between the sample chamber and the sample exchange chamber
An object of the present invention is to provide an electrostatic chucking mechanism and an electron beam lithography apparatus which can completely maintain a vacuum in a sample chamber by blocking, and can simplify maintenance and shorten operation time.

[0008]

The present invention achieves the above object.
In order to achieve this, it is basically configured as follows. One
Goes while holding the sample between the sample chamber and the sample exchange chamber.
Incoming sample transport holder and the sample transport holder
And a sample transfer table on which the sample transfer holder is mounted.
Is provided with an insulating substrate and a first electrode on the upper surface side of the insulating substrate.
The upper electrostatic adsorption member for adsorbing the sample,
Sample transfer table laminated on the lower surface side of the substrate via the second electrode
Made and a lower electrostatic adsorbing member for adsorbing, the lower static
By providing a hole from the electro-adsorption member to the insulating substrate,
A common terminal conducting to the first and second electrodes is introduced into the hole.
Is, on the other hand, the sample transport holder mounting surface of said specimen moving stage
When the sample transport holder is positioned and mounted
The common terminal is provided with a power supply terminal that is pressed against the spring by the force of the spring.
The electrostatic adsorption mechanism of the sample (the first
Akira) . The other is a sample exchange chamber for storing samples,
Movement to move the sample carried in from the exchange room
A sample chamber having a table inside;
An electron beam lithography system having an electron beam column for irradiating a child beam.
Thus, the space between the sample exchange chamber and the sample chamber and the sample
The first one for coming and going together and electrostatically adsorbing the sample on the substrate
Electrodes and for electrostatically adsorbing the substrate to the sample stage
To the second electrode, and the first and second electrodes.
A sample transfer hood having an introduction terminal
And the sample transfer holder is fixed to a predetermined position of the sample moving table.
A positioning mechanism for mounting the sample on the position,
When the sample transfer holder is mounted, the moving table
Make sure that a power supply terminal is
An electron beam lithography apparatus (second invention) .

According to the first and second aspects of the present invention, the first electrode for adsorbing the sample (electrostatic adsorption) and the second electrode for adsorbing the sample moving table (electrostatic adsorption) are provided on the sample transfer holder side. And an introduction terminal for these first and second electrodes, and a power supply terminal connected to the introduction terminal on the sample transfer holder side when the sample transfer holder is mounted on the sample moving table side. Since the sample transfer holder is provided, the introduction terminal on the sample transfer holder side and the power supply terminal on the sample transfer table side come into contact and are naturally connected only when the sample transfer holder is mounted on the sample transfer table.
When the sample transfer holder is placed on the sample transfer table, a voltage is applied to the first and second electrodes on the sample transfer holder side via the power supply terminal and the introduction terminal, thereby moving the sample, the sample transfer holder, and the sample transfer unit. Since the tables are electrostatically attracted to each other, highly accurate positioning of the sample can be realized. When the application of voltage to the first and second electrodes is stopped, the electrostatic attraction force is released,
The sample transfer holder can be separated from the sample moving table as it is, and the sample transfer holder can move between the sample chamber and the sample exchange chamber. Sample transfer holder according to the present invention
Has the first and second electrodes for electrostatic attraction as described above.
However, the power is supplied to the power supply terminal
Since this is performed by contact of the lead-in terminal on the holder side, the sample
Since the power supply wiring can be eliminated on the transfer holder side,
Do not pull out the power supply wiring from the feeder holder.
Therefore, the sample transfer holder is located between the sample chamber and sample exchange chamber.
Wiring straddles both the sample chamber and sample exchange chamber when
As a result, there is no
In this case, completely block the space between the sample chamber and sample
The vacuum in the chamber can be maintained. Therefore, sample transfer
Double-sided electrostatic chuck on sample holder (sample / sample transfer holder / sample
Even if a mechanism (electrostatic attraction between moving tables) is adopted,
The vacuum in the sample chamber can be prevented from lowering as much as possible.

When the maintenance of the electrostatic chucking mechanism is performed, the sample transport holder may be moved from the sample chamber to the sample exchange chamber and taken out of the sample exchange chamber. And maintenance work can be simplified. Furthermore, in the first invention
According to one introduction terminal, the first and the second
Voltage can be applied to the two electrodes at the same time.
Since only one power supply circuit is required, circuit simplification and cost reduction
Can be reduced.

[0011]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a part of a sample transfer holder and a sample moving table according to the present embodiment. FIG. 2 is a schematic diagram of an electron beam drawing system in a semiconductor manufacturing process showing an example of an object to which the present embodiment is applied. It is a perspective view.

In FIG. 2, reference numeral 20 denotes a sample chamber, which is provided with an electron beam column 21 and has a movable table (for example, X,
Y stage) 14 is arranged. The position of the sample moving table 14 is controlled by an X-axis and Y-axis moving mechanism (not shown). In addition, a vacuum chamber is formed in the sample chamber 20 by the evacuation action of the vacuum pump.

Reference numeral 22 denotes a sample exchange chamber provided adjacent to the sample chamber 20, which can be brought into a vacuum state (the degree of vacuum is lower than that of the sample chamber) by a vacuum pump. Is stored.

[0015] Between the sample chamber 20 and the sample exchange chamber 22,
A passage port 23 through which the sample transport holder 1 passes is provided,
This passage 23 can be opened and closed by a shutter 24.

When performing electron beam lithography on a sample, the sample is set on the sample transfer holder 1 in the sample exchange chamber 22, and then the sample transfer holder 1 is transferred to the sample transfer table 14 in the sample chamber 20. (Not shown). When the electron beam writing is completed, the sample is transported together with the sample transport holder 1 from the sample chamber 20 to the sample exchange chamber 22, where the processed sample is taken out, replaced with a new sample, and again. The sample holder 1 is transported to the sample moving table 14 in the sample chamber 20.

In the sample exchange process, a state in which the passage port 23 is open (a process in which the sample holder 1 moves back and forth).
Then, the sample exchange chamber 22 is also in a vacuum state and the vacuum drop on the sample chamber 20 side is suppressed as much as possible. When removing the sample from the sample exchange chamber 22, the passage opening 23 is closed to prevent the vacuum drop in the sample chamber 20. doing.

Next, the sample transport holder 1 in this embodiment will be described in detail with reference to FIG.

The sample transport holder 1 comprises a frame 2, an electrostatic chuck mechanism 3, a pin 4a for positioning the sample, a spring 4b, and the like.

The electrostatic suction mechanism 3 includes an insulating substrate 5 and an insulating substrate.
Sample adsorption laminated on the upper surface side of the plate 5 via the first electrode 6
Upper electrostatic attraction member 8 and a second
Lower electrostatic force for adsorbing the sample moving table stacked via the electrodes 7
And a suction member 9. Here, film-like electrodes 6 and 7 are formed on both surfaces of the insulating substrate 5, and electrostatic attraction members 8 and 9 are provided so as to be in contact with the electrodes 6 and 7. That is,
The electrostatic attraction members 8 and 9 are stacked so as to sandwich the insulating substrate 5 with the electrode film in a sandwich manner. Electrostatic suction members 8, 9
Is made of a member having a high dielectric constant, such as Sic, and has a smooth surface by machining.

Reference numeral 10 denotes a lead-in terminal for applying the electrodes 6 and 7, and a hole 1 extending from the lower electrostatic attraction member 9 to the insulating substrate 5.
1 and a common hole which is electrically connected to the electrodes 6 and 7 in the hole 11.
Introduction terminal 10 is Ru is introduced. In this embodiment, pin in the hole 11
The insertion terminal 10 is inserted and fixed in the
0 is in contact with the electrode 6 and the electrode 7. In this way, an electrostatic chucking mechanism that is the main body of the transport holder 1 is formed.
You.

The sample positioning pin 4a is disposed on the sample mounting surface side of the holder 1 on the frame 2, and the pin 4a
A spring 4b for holding the sample 12 in cooperation with a is disposed on the frame 2. A pin hole 13 for positioning on the sample moving table 14 is provided on the lower surface of the frame 2.

The sample transfer table 14 has a sample transfer holder contact surface 15 smoothed by machining on the upper surface thereof, and positioning pins 16 around the contact surface 15 corresponding to the positioning holes 13 on the sample transfer holder 1 side. A power supply terminal 17 that is in electrical contact with the introduction terminal 10 on the sample transfer holder 1 side is provided on the sample transfer holder contact surface 15. The power supply terminal 17 is provided in the hole 1 provided in the sample moving table 14.
9 is supported by a spring 18, and a part thereof is assembled so as to protrude from the holder contact surface 15.

Next, the setting of the sample 12 on the sample transfer holder 1 and the mounting of the sample transfer holder 1 on the sample moving table 14 will be described.

When the sample 12 is set on the sample transfer holder 1, the sample 12 is set in the sample exchange chamber 22 as shown in FIG. First, the sample holding spring 4b is opened, and the sample 1
After the sample 2 is brought into contact with the sample positioning pin 4a and positioned, the sample 12 is held on the electrostatic attraction member 8 by the force of the spring 4b.

The sample transport holder 1 holding the sample 12 is
The sample is transferred from the sample exchange chamber 22 onto the sample moving table 14 in the sample chamber 20, and undergoes a moving process shown by an arrow in FIG.
The sample transport holder 1 is positioned on the sample moving table 14 by fitting the pins 16 to the sample transfer table 14 and placed on the holder contact surface 15. At this time, the power supply terminal 17 and the introduction terminal 10 are in contact with each other.
Is applied to the electrostatic attraction members 8 and 9 disposed on both surfaces of the holder 1, static electricity is charged, the electrostatic attraction member 8 attracts the sample 12, and the electrostatic attraction member 9 is attached to the sample on the sample moving table 14 side. Attach to the transfer holder contact surface 15.

The electrostatic attraction member 8 has a smooth surface that generates a necessary and sufficient attraction force for correcting and flattening the sample 12. Even if the acceleration is applied, a sufficient and sufficient suction force is generated to hold the sample transport holder 1 without displacement.

According to the present embodiment, the sample transport holder 1
One of the electrostatic attraction members 8 performs positioning and fixing / holding while correcting the sample 12 to be flat, and the other electrostatic attraction member 9 carries out fixing and holding to the sample moving table 14, and performs processing and inspection of the sample. Guarantee accuracy. Specifically, when the present embodiment is applied to an apparatus using a charged particle beam such as an electron beam lithography apparatus, the sample holder is machined to a flatness of 5 μm / 100 mm, and the charged particle beam is moved by 2 mm on the sample. When this was done, the amount of displacement of the charged particle beam due to the warpage of the sample was 5 × 1
Since it can be suppressed to 0 × 1/10 ³ μm or less,
High-precision processing, inspection, and measurement using charged particle beams become possible.

Further, by using an electrostatic attraction mechanism for fixing and holding the sample 12 on the holder 1 and for fixing and holding the holder 1 on the sample moving table 14, the kind of the fixing and holding mechanism can be simplified. I can figure it out. Further, only when the sample transfer holder 1 is mounted on the sample transfer table 14, the introduction terminal 10 on the sample transfer holder 1 side and the power supply terminal 17 on the sample transfer table 14 side are connected. Is the sample moving table 14
Sometimes away from, it makes it possible to come and go between the sample chamber 20 and the specimen-exchange chamber 22. That is, for electrostatic attraction
Is supplied to the first and second electrodes 6 and 7 by the sample moving table 14.
Power supply terminal 17 on the side and introduction terminal 10 on the sample transport holder 1 side
Of the sample transfer holder 1 side.
Eliminating the power wiring allows the power supply wiring from the sample transport holder 1
The sample chamber of the sample transfer holder 1 without being pulled out
The wiring between the sample room and the sample exchange room 22
It does not straddle both of the switching rooms. As a result,
When performing the exchange, the sample chamber 20 and the sample exchange chamber 22 are exchanged.
It is possible to completely maintain the vacuum in the sample chamber by completely blocking the space.
You. Therefore, double-sided electrostatic adsorption (sample 12
The mechanism for electrostatic attraction between the holder 1 and the sample moving table 14)
Even if the sample chamber 20 is provided, the vacuum in the sample chamber 20 may be reduced when the sample is exchanged.
It can be prevented as much as possible. In addition, by providing all of these electrostatic suction mechanisms on the sample transfer holder 1 side, maintenance of the electrostatic suction mechanism can be performed by taking out the sample transfer holder 1 in the sample exchange chamber 22 and performing the maintenance as in the conventional case. There is no case in which the sample chamber is brought into the atmospheric state and the moving table of the sample chamber is taken out. Therefore, the sample chamber 20 can maintain a high vacuum state during this kind of maintenance. Although the sample exchange chamber 22 is in the air state during the above maintenance, the degree of vacuum is lower than that of the sample chamber 20 and the management thereof is simple, so that it is easy to return to the vacuum. As a result, maintenance can be simplified and time can be greatly reduced.

In the above embodiment, the voltage is applied to the electrodes 6 and 7 for the electrostatic attraction members 8 and 9 via the power supply terminal 17 after the sample transfer holder 1 is set on the sample moving table 14. A sample can be electrostatically adsorbed by incorporating a battery in the device 1 so that the battery can be applied at least while the electrostatic adsorption member 8 on the sample mounting side is being conveyed.

[0031]

According to the present invention, in an electrostatic chucking mechanism and an electron beam lithography apparatus, a highly accurate positioning, fixing and fixing of a sample can be achieved while simplifying a mechanism of a sample transfer holder and a sample moving table.
The sample chamber and the sample exchange chamber can be held
Can completely block the space of the sample and maintain the vacuum in the sample chamber.
In addition, maintenance can be simplified and work time can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a part of a sample transfer holder and a sample moving table according to an embodiment of the present invention.

FIG. 2 is a perspective view schematically showing an electron beam lithography apparatus as an example to which the above embodiment is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample transfer holder, 3 ... Electrostatic adsorption mechanism, 4a, 4b ...
Sample positioning member (positioning pin, spring), 5: insulating substrate, 6, 7: electrode, 8, 9: electrostatic attraction member, 10: introduction terminal, 12: sample, 13: holder positioning hole, 14: sample moving table , 16: Holder positioning pin, 17: Power supply terminal, 20: Sample chamber, 22: Sample exchange chamber, 25: Sample exchange table.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-214517 (JP, A) JP-A-2-196442 (JP, A) JP-A-59-79545 (JP, A) JP-A-62 286249 (JP, A) JP-A-2-263398 (JP, A) JP-A-1-78023 (JP, U) JP-A-2-135141 (JP, U) JP-A-61-70935 (JP, U) Actual opening Hei 3-10528 (JP, U)

Claims (2)

(57) [Claims] 1. A and sample transfer holder to and from while holding the sample between the sample chamber and the sample exchange chamber, the trial in the sample chamber side
A sample transfer table on which a sample transfer holder is mounted, wherein the sample transfer holder includes an insulating substrate and an upper surface of the insulating substrate.
Upper electrostatic layer for sample adsorption laminated on the side via the first electrode
A suction member and a lower surface of the insulating substrate via a second electrode;
And a lower electrostatic adsorption member for adsorbing the stacked sample moving table.
And a hole is provided from the lower electrostatic attraction member to the insulating substrate.
In addition, a common hole that is electrically connected to the first and second electrodes is formed in this hole.
The terminal is introduced, while the sample transfer holder mounting surface of the sample transfer table is
When the sample carrier is positioned and mounted,
Power feed terminals that are pressed into contact with the through terminals by spring force
A sample electrostatic adsorption mechanism. A sample exchange chamber for accommodating the sample;
The sample transfer table for moving the sample carried in from the transfer room
A sample chamber provided inside and an electron beam for the sample in the sample chamber.
An electron beam lithography system equipped with an electron beam column for irradiating
Between the sample exchange chamber and the sample chamber together with the sample.
And a first electrode for electrostatically adsorbing the sample on the substrate
And a second step for electrostatically adsorbing the substrate to the sample moving table.
2 electrode and the first and second electrodes.
Transfer holder having an introduction terminal introduced for the purpose
And mounting the sample transport holder at a predetermined position on the sample moving table.
And a positioning mechanism for mounting the sample transfer table , wherein the sample transfer table is mounted when the sample transfer holder is mounted.
A power supply terminal at a position where the introduction terminal is located.
An electron beam lithography apparatus, comprising: