KR20230174666A - An electric potenrial barrier module and a lithography apparatus including the same - Google Patents

Abstract

The present invention relates to an electrical potential barrier module and a lithography device including the same, and specifically to an electrical potential barrier module capable of performing the function of a pellicle in a lithography device and a lithography device including the same.

Description

Electric potential barrier module and lithographic apparatus including same {AN ELECTRIC POTENRIAL BARRIER MODULE AND A LITHOGRAPHY APPARATUS INCLUDING THE SAME}

The present invention relates to an electrical potential barrier module and a lithography device including the same, and specifically to an electrical potential barrier module capable of performing the function of a pellicle in a lithography device and a lithography device including the same.

When manufacturing semiconductor devices, a method called photolithography is used to pattern a semiconductor wafer. In photolithography, a photomask is used as a patterning original, and the pattern on the photomask is transferred to the wafer.

However, if dust attaches to the photo mask, light is absorbed or reflected due to the dust, causing damage to the transferred pattern, resulting in a decrease in the performance or yield of the semiconductor device.

Therefore, these works are usually performed in a clean room, but since dust exists even in a clean room, a method of attaching a pellicle is used to prevent dust from attaching to the surface of the photo mask.

In this case, the dust is not attached directly to the surface of the photo mask, but is attached to the pellicle film. In the lithography process, the focus is aligned with the pattern of the photo mask, so the dust on the pellicle is out of focus and is not transferred to the pattern. there is.

The pellicle must have good exposure light transmittance, so it is composed of a very thin film. A pellicle with a thin film structure can cause damage or sagging of the thin film due to external impact or stress on the thin film itself.

Since such damage or sagging can distort the image during the pattern transfer process, it is necessary to maintain the mechanical strength of the pellicle thin film to maintain a complete flat state without sagging or damage.

For this purpose, a method is used to prevent distortion of the pellicle thin film by applying appropriate tension (Tensile Stress) to the thin film itself or by additionally forming a reinforcing layer. This method not only causes complexity in the pellicle manufacturing process, but also causes the reinforcement layer to be damaged. There are many difficulties in developing pellicle for extreme ultraviolet lithography, such as the problem of deterioration of the characteristics of the pellicle thin film due to addition.

Therefore, there is a need to develop a foreign matter prevention module with a new structure that can replace the function of the pellicle described above and a lithography device including the same.

The electrical potential barrier module and the lithographic apparatus equipped with the same according to an embodiment of the present invention aim to solve the following problems in order to solve the above-mentioned conventional problems.

An electric potential barrier module and lithography device that can minimize the inflow of foreign matter into the mask side without using a conventional physical pellicle to prevent foreign matter from the mask side are provided.

The problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the description below.

An electrical potential barrier module according to an embodiment of the present invention relates to a barrier module for blocking the inflow of foreign matter into a mask disposed at the top inside the chamber of a lithography apparatus, wherein the barrier module directs an electron beam to a lower area of the mask. Emitted to form an electrical potential barrier, the position of the barrier module inside the chamber is determined based on the spread area of the electron beam due to the repulsive force between electrons constituting the electron beam.

A filament that generates an electron beam; and a housing formed to accommodate the filament therein, and having a slit formed in the longitudinal direction to emit the electron beam in a direction parallel to the bottom of the mask.

The housing is preferably arranged to be spaced apart from the mask in the vertical and horizontal directions by a preset distance.

The housing is preferably arranged to be spaced apart from the mask so that part or all of the bottom of the mask can be located within the spread area of the electron beam.

A lithographic apparatus according to an embodiment of the present invention includes a chamber whose interior is maintained in a vacuum state; a light source unit disposed within the chamber and generating light for lithography; a mask disposed at the top of the chamber; An optical system that transmits the light generated by the light source unit to the mask; And a barrier module that emits an electron beam to a lower area of the mask to form an electrical potential barrier to block the inflow of particles into the mask, wherein the placement position of the barrier module determines the repulsion force between electrons constituting the electron beam. It is determined based on the spread area of the electron beam.

The barrier module includes a filament that generates an electron beam; and a housing formed to accommodate the filament therein, and having a slit formed in the longitudinal direction to emit the electron beam in a direction parallel to the bottom of the mask.

The housing is preferably arranged to be spaced apart from the mask in the vertical and horizontal directions by a preset distance.

The housing is preferably arranged to be spaced apart from the mask so that part or all of the bottom of the mask can be located within the spread area of the electron beam.

The electrical potential barrier module and lithography device according to an embodiment of the present invention emits an electron beam into the lower area of the mask to form an electrical potential barrier, thereby preventing foreign substances flowing inside the chamber from entering the mask side. You can expect it.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below.

1 is a diagram schematically showing a lithography apparatus according to an embodiment of the present invention.
Figure 2 is a schematic perspective view of an electrical potential barrier module according to an embodiment of the present invention.
Figures 3 and 4 are diagrams showing the process of forming an electric potential barrier by electron beam emission in the electric potential barrier module of Figure 2.
Figures 5 and 6 are diagrams to explain the arrangement of the barrier module and the mask to increase the effect of preventing foreign matter from entering the mask.

Preferred embodiments according to the present invention will be described in detail with reference to the attached drawings, but identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

Additionally, when describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted. In addition, it should be noted that the attached drawings are only intended to facilitate easy understanding of the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the attached drawings.

The present invention relates to a technical feature for preventing particles such as dust moving inside a chamber from moving to the other side of the barrier module, that is, the mask side, by using a barrier module composed of a potential barrier rather than a physical barrier. In particular, the present invention relates to technical features such as dust. The movement of particles is not blocked by physical collision with the barrier module, but by the electrical potential barrier.

In this way, the barrier module that forms an electrical potential barrier is used in a lithography device to prevent particles such as dust located in a chamber such as a lithography light source from moving to the mask, thereby preventing foreign matter from entering the EUV lithography device in a physical manner. It becomes possible not to use a pellicle to prevent .

Hereinafter, the lithography apparatus and the electrical potential barrier module according to this embodiment will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the lithography apparatus according to an embodiment of the present invention includes a chamber 100, a light source unit 200, a mask 300, an optical system 400, a wafer stage 500, and a barrier module 600. It is designed to include

The chamber 100 performs the function of accommodating each component of the lithography apparatus and must be closed to the outside to prevent the inflow of foreign substances from the outside. In particular, in the case of a lithography process using an EUV light source, the EUV light is absorbed in the air. In order to minimize this, it is preferable that the inside of the chamber 100 is maintained in a vacuum state.

The light source unit 200 performs a function of generating light for a photolithography process, and the light source unit 200 of the lithography device according to an embodiment of the present invention generates EUV light 10 for forming fine patterns. desirable.

The EUV light 10 generated in the light source unit 200 is transmitted to the mask 300 on which the fine circuit pattern is formed through the first optical system 400a, and the EUV light 10 passing through the mask 300 is transmitted to the second optical system 400a. It is delivered to the wafer placed on the wafer stage 500 through 400b, and at this time, the photosensitive material coated on the wafer reacts with the EUV light 10 to form a pattern on the wafer.

Meanwhile, in the case of the EUV light 10, as described above, since its wavelength is very short, it is easily absorbed, so the optical system 400 including the first optical system 400a and the second optical system 400b is used in a conventional lithography device. It is preferable that it consists of at least one reflector rather than the lens used.

The barrier module 600 is configured to prevent particles such as dust inside the chamber 100 from entering the mask 300, and emits an electron beam to the lower area of the mask 300 to prevent particles from entering the mask 300. Performs a blocking function.

That is, the barrier module 600 is configured to form an electric potential barrier by an electron beam at the bottom of the mask 300, thereby preventing foreign substances from settling on the mask 300 even without a separate pellicle, which is a conventional physical barrier. It becomes possible.

This barrier module 600 may be configured to include a filament 610, a housing 620, and an anode 630, as shown in FIGS. 2 to 4.

The filament 610 is made of tungsten, etc., and can be formed into a long shape in the longitudinal direction. When the filament 610 is heated to a high temperature by applying a current to the filament 610, it is bound to the surface of the filament 610. Electrons may escape and form an electron beam.

The anode 630 performs the function of accelerating the electron beam, and the housing 620 accommodates the filament 610 and the anode 630 inside, and a longitudinal slit 621 is formed so that the electron beam can be emitted to the outside. It can be.

The electron beam passing through the slit 621 forms an electrical potential barrier 20 in a planar shape parallel to the bottom surface of the mask 300, as shown in FIGS. 2 and 3, thereby allowing particles located below to move toward the mask 300. Entry can be prevented.

Specifically, if particles such as dust inside the chamber 100 have a negative charge, they cannot pass through the electrical potential barrier 20 of the barrier module 600 and move toward the mask 300.

In addition, even if particles such as dust inside the chamber 100 carry a positive (+) charge or do not carry a charge, when they move near the electric potential barrier 20 composed of an electron beam, the particles acquire a negative (-) charge. Therefore, it cannot move toward the mask 300 due to the electrical potential barrier 20 of the barrier module 120.

Meanwhile, in the case of the electron beam passing through the slit 621, as the distance from the emission area increases, it gradually spreads as shown in FIG. 4 due to the repulsive force between electrons in the electron beam, which causes the electron beam within the electrical potential barrier 20 made of the electron beam. The density of electrons decreases as the distance from the barrier module 600 increases.

Therefore, as shown in FIG. 5, the position of the barrier module 600 may be set so that an area where the electron density of the electrical potential barrier 20 is somewhat swamped can be placed under the mask 300. However, according to the present invention, The lithography apparatus according to one embodiment proposes setting the position of the barrier module 600 so that part or all of the bottom of the mask 300 is located within the electron beam spreading area 21, as shown in FIG. 6.

As shown in FIG. 6, when part or all of the bottom of the mask 300 is located within the electron beam spreading area 21, the bottom of the mask 300 is placed under an electronic atmosphere, and as a result, the bottom of the mask 300 is It has a negative (-) charge.

At this time, even if the particles in the chamber 100 settle on the bottom surface of the mask 300 through the spread area 21 of the electrical potential barrier where electrons are arranged at a relatively low density, negative energy is generated in the process of the particles passing through the spread area 21. It has a negative (-) charge, and when it contacts the bottom of the mask 300 in a negative (-) state, the particles are prevented from settling on the bottom of the mask 300 due to electrical repulsion.

That is, when the barrier module 600 is configured as in the embodiment of the present invention, particles such as dust present in the chamber 100 are blocked from moving to the mask 300 by an electrical potential barrier rather than a physical barrier, Dust is prevented from attaching to the mask 300 during the lithography process.

As a result, the lithography device according to the present invention does not require a pellicle, so the complicated process for manufacturing the pellicle can be omitted. Furthermore, unlike the pellicle, the barrier module 600 can be used semi-permanently, thereby reducing the cost of lithography. can do.

Above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to the specific embodiments and should be interpreted in accordance with the appended claims. Additionally, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

100: chamber
200: Light source unit
300: mask
400: Optical system
500: wafer stage
600: Barrier module

Claims (8)

In the barrier module for blocking the inflow of foreign substances into the mask disposed at the top inside the chamber of the lithography apparatus,
The barrier module emits an electron beam into the lower area of the mask to form an electrical potential barrier,
An electrical potential barrier module in which the position of the barrier module inside the chamber is determined based on the spread area of the electron beam due to the repulsive force between electrons constituting the electron beam.
In claim 1,
A filament that generates an electron beam; and
a housing formed to accommodate the filament inside, and having a slit formed in the longitudinal direction to emit the electron beam in a direction parallel to the bottom of the mask;
An electrical potential barrier module comprising:
In claim 2,
The electrical potential barrier module is characterized in that the housing is arranged to be spaced apart in the vertical and horizontal directions by a preset distance from the mask.
In claim 2,
The electrical potential barrier module, wherein the housing is arranged to be spaced apart from the mask so that part or all of the bottom of the mask can be located within the spread area of the electron beam.
A chamber whose interior is maintained in a vacuum state;
a light source unit disposed within the chamber and generating light for lithography;
a mask disposed at the top of the chamber;
An optical system that transmits the light generated by the light source unit to the mask; and
a barrier module that emits an electron beam into a lower area of the mask to form an electrical potential barrier to block particles from entering the mask;
Including,
A lithography apparatus in which the placement position of the barrier module is determined based on the spread area of the electron beam due to repulsion between electrons constituting the electron beam.
The method of claim 5, wherein the barrier module,
A filament that generates an electron beam; and
a housing formed to accommodate the filament inside, and having a slit formed in the longitudinal direction to emit the electron beam in a direction parallel to the bottom of the mask;
A lithographic apparatus comprising:
In claim 6,
The lithography apparatus is characterized in that the housing is arranged to be spaced apart from the mask in the vertical and horizontal directions by a preset distance.
In claim 6,
The lithography apparatus is characterized in that the housing is arranged to be spaced apart from the mask so that part or all of the bottom of the mask is located within the spread area of the electron beam.

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