CN116736640A - Anti-pollution protection device, objective lens and photoetching machine - Google Patents

Abstract

The invention discloses an anti-pollution protection device, an objective lens and a photolithography machine, and belongs to the field of semiconductor technology. The anti-pollution protection device includes a field of view baffle and an annular main structure. The airflow passes through the air inlet and sequentially passes through the first annular channel and the second annular channel. The airflow after entering the accommodation cavity from the second annular channel is finally discharged from the field of view window. A gas layer is formed in the accommodation cavity to protect the lens from contamination, so that the light beam can be projected onto the workpiece through the accommodation cavity and the field of view window after passing through the lens. Due to the homogenization process in the second annular channel and the first annular channel, It makes the outlet air flow more even and avoids local vortices to form pollutant retention areas; it can also effectively resist lateral wind disturbance.

Description

An anti-pollution protection device, objective lens and photolithography machine

Technical field

The invention relates to the field of semiconductor technology, and in particular to an anti-pollution protection device, an objective lens and a photolithography machine.

Background technique

The semiconductor industry is the backbone of the high-tech and information age. Among them, the photolithography technology that sequentially transfers the chip patterns on the mask plate to the corresponding layers of the silicon wafer through exposure to manufacture the required chips is considered to be the core technology in the semiconductor industry chain. However, the photolithography process is inside the photolithography machine, and the organic contamination produced by the photoresist and exposure process on the surface of the objective lens has always hindered the accuracy of photolithography.

The gas bath device is one of the important means of pollution prevention and control. Based on fluid mechanics, by changing the fluid flow rate, flow channel shape, size or air outlet direction, the high-speed inlet flow can be evenly distributed on the surface of the objective lens to form an air curtain to prevent contact with contamination. In addition, the gas bath can also effectively reduce the ambient temperature to prevent photoresist volatilization and contamination caused by high temperatures. However, in the actual internal flow channel design, the outlet airflow cannot be uniform and is disturbed by lateral wind, which easily generates local vortices to form pollutant retention areas, seriously reducing the production efficiency of silicon wafers.

For this reason, there is an urgent need to provide an anti-pollution protection device, an objective lens and a photolithography machine to solve the above problems.

Contents of the invention

The purpose of the present invention is to provide an anti-pollution protection device, an objective lens and a photolithography machine, which can make the outlet air flow more uniform, avoid local vortices to form pollutant retention areas, and effectively resist lateral wind disturbance.

To achieve the above goals, the following technical solutions are provided:

An anti-pollution protection device including:

The annular main structure includes an accommodation cavity, a first annular channel and a second annular channel arranged sequentially from the inside to the outside. The outer wall of the second annular channel is provided with an air inlet, and the second annular channel is connected to the first annular channel. The annular channel is connected, the first annular channel is connected with the accommodation cavity, and the accommodation cavity penetrates the annular main structure along the axial direction of the first annular channel;

A field of view baffle is provided in the accommodation cavity and connected to the annular main structure. The field of view baffle includes a field of view baffle body, and a field of view window is provided on the field of view baffle body. The field of view window passes through the field of view baffle body along the axial direction of the first annular channel.

As an optional solution to the anti-pollution protection device, the second annular channel is provided with a plurality of communication holes at circumferential intervals, and the second annular channel is connected to the first annular channel through the communication holes.

As an optional solution to the anti-pollution protection device, the communication hole and the air inlet are arranged non-coaxially.

As an optional solution to the anti-pollution protection device, the first annular channel is provided with a plurality of nozzles at circumferential intervals, and the first annular channel is connected to the accommodation chamber through the nozzles.

As an optional solution to the anti-pollution protection device, the field of view baffle also includes an airflow homogenizing plate, which is annularly arranged on the field of view baffle body, and is connected to the airflow homogenizing plate. The field baffle body is arranged at a first preset angle B, and the height of the upper end surface of the airflow homogenizing plate is not less than the height of the nozzle.

As an optional solution for the anti-pollution protection device, the angle between the airflow homogenizing plate and the field baffle body is a rounded corner or a sharp corner.

As an optional solution to the anti-pollution protection device, an airflow baffle extending toward the center is circumferentially provided on the annular main structure on the side of the nozzle away from the field of view baffle, and the lower part of the airflow baffle is There is a gap between the end surface and the upper end surface of the airflow homogenizing plate.

As an optional solution to the anti-pollution protection device, the field of view baffle also includes an air flow guide plate, the air flow guide plate is annularly arranged on the field of view baffle body, and the air flow guide plate is connected with the The field baffle body is arranged at a second preset angle C, and the height of the air flow guide plate is smaller than the height of the air flow homogenizing plate.

As an optional solution for the anti-pollution protection device, the airflow homogenizing plate extends obliquely in a direction close to the nozzle, and the first preset angle between the airflow homogenizing plate and the field of view baffle body is B is 25°-85°.

As an optional solution to the anti-pollution protection device, the airflow guide plate extends obliquely in a direction away from the nozzle, and the second preset angle between the airflow guide plate and the field of view baffle body C is 25°-40°.

As an optional solution to the anti-pollution protection device, a first powder cleaning hole is provided through the outer annular wall of the second annular channel, and a second powder cleaning hole is provided on the first annular channel.

As an optional solution to the anti-pollution protection device, the air inlet extends along the radial direction of the second annular channel.

An objective lens, including an objective lens and an anti-pollution protection device as described in any one of the above, the objective lens is arranged on the side of the annular main structure away from the field of view baffle, and the objective lens is coaxially arranged with the field of view window .

A photolithography machine includes the above objective lens.

Compared with the existing technology, the beneficial effects of the present invention are:

The anti-pollution protection device provided by the present invention includes a field of view baffle and an annular main structure. The airflow passes through the air inlet and sequentially passes through the first annular channel and the second annular channel. The airflow after entering the accommodation cavity through the second annular channel finally exits from the viewing area. The field window is discharged, and a gas layer is formed in the accommodation cavity to protect the lens from contamination, so that the light beam can be projected onto the workpiece through the accommodation cavity and the field of view window after passing through the lens. This makes the outlet airflow more uniform, avoids local vortex formation and forms pollutant retention areas, and can also effectively resist lateral wind disturbance.

In the objective lens provided by the present invention, the objective lens is arranged on the side of the annular main structure away from the field of view baffle 1. Through the protective gas layer formed in the accommodation cavity that is fully homogenized and resistant to lateral disturbance, the surface quality of the objective lens is improved. Cleanliness.

The photolithography machine provided by the present invention can form a protective gas layer that is fully homogenized and resistant to lateral disturbance on the surface of the objective lens to be protected, thereby ensuring the etching accuracy of the photolithography machine.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, a brief introduction will be made below to the drawings needed to describe the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. , For those of ordinary skill in the art, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings without exerting creative efforts.

Figure 1 is a schematic assembly diagram of the anti-pollution protection device in the embodiment of the present invention;

Figure 2 is an explosion schematic diagram of the anti-pollution protection device in the embodiment of the present invention;

Figure 3 is a cross-sectional view of the anti-pollution protection device in the embodiment of the present invention;

Figure 4 is a cross-sectional view of the annular main structure in the embodiment of the present invention;

Figure 5 is a partial enlarged view of position A in Figure 4;

Figure 6 is a cross-sectional view of the field baffle body in the embodiment of the present invention;

Figure 7 is a first structural schematic diagram of the field of view window in the embodiment of the present invention;

Figure 8 is a second structural schematic diagram of the field of view window in the embodiment of the present invention;

Figure 9 is a schematic structural diagram of the ring-shaped main structure from below in the embodiment of the present invention.

Reference signs:

1. Field of view baffle; 2. Ring-shaped main structure; 3. First powder cleaning hole; 4. Second powder cleaning hole; 5. First mounting hole; 6. Second mounting hole; 7. Sealing head;

11. Field of view baffle body; 12. Field of view window; 13. Airflow homogenizing plate; 14. Airflow deflector;

21. Accommodation cavity; 22. First annular channel; 221. Nozzle; 23. Second annular channel; 231. Air inlet; 232. Communication hole; 24. Air flow baffle.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Therefore, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or The positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is customarily placed when used. It is only for the convenience of describing the invention and simplifying the description, and does not indicate or imply the device referred to. Or elements must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations on the invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish descriptions and shall not be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should also be noted that, unless otherwise clearly stated and limited, the terms "set" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or Integrally connected; can be mechanical or electrical. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

In the present invention, unless otherwise expressly provided and limited, the term "above" or "below" a first feature of a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention.

In order to achieve greater uniformity of the outlet airflow, avoid local vortices to form pollutant retention areas, and effectively resist lateral wind disturbance, this embodiment provides an anti-pollution protection device. The specific details of this embodiment are described below with reference to Figures 1 to 9 Contents are described in detail.

As shown in Figures 1 to 5, the anti-pollution protection device includes a field of view baffle 1 and an annular main structure 2. The annular main structure 2 includes an accommodation cavity 21, a first annular channel 22 and a second annular channel arranged sequentially from the inside to the outside. The outer wall of the channel 23 and the second annular channel 23 has an air inlet 231 extending through it. As shown in FIG. 4 combined with FIG. 5 , the second annular channel 23 is connected with the first annular channel 22 , and the first annular channel 22 is connected with the accommodation cavity 21 . Since the accommodating cavity 21 penetrates the annular main structure 2 along the axial direction of the first annular channel 22, the air flow flows in from the air inlet 231 and flows out from the accommodating cavity 21. The cross section of the accommodating cavity 21 may be, but is not limited to, circular or elliptical. , rectangular and irregular shapes, etc., the cross-section of the accommodation cavity 21 is preferably circular. The field of view baffle 1 is disposed in the accommodation cavity 21 and connected to the annular main structure 2. The field of view baffle 1 can be detachably connected to the annular main structure 2. The field of view baffle 1 includes a field of view baffle body 11 . A field of view window 12 is provided on the field of view baffle body 11 . The field of view window 12 penetrates the field of view baffle body 11 along the axial direction of the first annular channel 22 . The field of view window 12 is opened on the field of view baffle body 11 , and the final shape of the field of view is determined by the shape of the field of view window 12 . Since the field of view baffle 1 is disposed in the accommodating cavity 21, the position of the field of view window 12 and the accommodating cavity 21 are relatively arranged to avoid blocking light.

For example, the air inlet 231 extends along the radial direction of the second annular channel 23 to facilitate the rapid flow of air into the second annular channel 23 . The air flow flows in from the air inlet 231 and is finally discharged from the field of view window 12. The direction of the air flow initially flowing into the anti-pollution protection device is perpendicular to the direction of final discharge of the anti-pollution protection device, so that the homogenized clean and dry gas flows out on the optical glass. The surface also forms a protective gas layer that can resist lateral disturbance. The optical glass in this embodiment is the objective lens.

In short, the anti-pollution protection device provided by the present invention includes a field of view baffle 1 and an annular main structure 2. Two inner and outer flow channels are distributed inside the annular main structure 2, which are a first connected annular channel 22 and a third annular channel 22. Two annular channels 23 are provided to avoid the problem that a single channel cannot fully homogenize the outlet air flow rate. In other examples, more than two sequentially connected flow channels may be distributed inside the annular main structure 2 , and may be three, four, five, six, etc. sequentially connected flow channels.

In other embodiments, the centers of the second annular channel 23 and the first annular channel 22 in the vertical direction may be at the same height or may be at different heights. The longitudinal cross-sections of the second annular channel 23 and the first annular channel 22 may be But it is not limited to circular, elliptical, rectangular, irregular shapes, etc. Preferably, the longitudinal cross-sectional area of the first annular channel 22 is larger than the longitudinal cross-sectional area of the second annular channel 23 .

Further, as shown in Figure 5, several communication holes 232 or communication channels are provided at circumferential intervals in the second annular channel 23, and the second annular channel 23 is connected to the first annular channel 22 through the communication holes 232 or communication channels. By adjusting the number and position height of the communication holes 232, the airflow uniformity effect can be further increased. Specifically, the air inlet surface of the communication hole 232 or the communication channel faces the inner cavity of the second annular channel 23 , and the air outlet surface of the communication hole 232 or the communication channel faces the inner cavity of the first annular channel 22 .

In some application scenarios, the connecting channel can be multiple disconnected channels or a continuous channel. The vertical height of the air outlet surface of the connecting channel can be adjusted according to the outlet flow velocity distribution requirements.

In some application scenarios, the extension direction of the communication hole 232 or the communication channel may be horizontal, may have a certain angle with the horizontal plane, or may be in an irregular serpentine shape, etc.

Exemplarily, a plurality of communication holes 232 are provided in a wave shape along the extending direction of the second annular channel 23 .

For example, the plurality of communication holes 232 may be located on the same horizontal plane, or may be arranged staggered up and down, without too many restrictions here.

Preferably, the air inlet 231 and the communication hole 232 are arranged non-coaxially, that is, the air flow from the air inlet 231 into the second annular channel 23 does not flow directly from the communication hole 232 into the first annular channel 22, but first flows with the inlet air. The corresponding side walls of the port 231 meet and play the role of diverting flow. Specifically, the air inlet 231 and the communication hole 232 are provided non-correspondingly.

The communication holes 232 on the second annular channel 23 are not evenly distributed in size, and the size and distribution of the holes can be adjusted according to the outlet flow velocity distribution requirements. The first annular channel 22 is provided with a plurality of nozzles 221 circumferentially spaced apart. The first annular channel 22 communicates with the accommodation cavity 21 through the nozzles 221. The airflow passes through the air inlet 231 and sequentially passes through the second annular channel 23 and the first annular channel 22. The air flow is ejected from a number of nozzles 221 of the first annular channel 22 and enters the accommodation cavity 21. The air flow is finally discharged from the field of view window 12, forming an air layer in the accommodation cavity 21 to protect the lens from being contaminated, so that the light beam passes behind the lens. It can be projected onto the workpiece through the accommodation cavity 21 and the field of view window 12. Since a plurality of communication holes 232 are provided at circumferential intervals in the second annular channel 23, a plurality of nozzles 221 are provided at circumferential intervals in the first annular channel 22. The hole size and distribution can also be adjusted according to the outlet airflow distribution requirements to make the outlet airflow more uniform and avoid local vortex formation to form pollutant retention areas; the circumferential arrangement of several nozzles 221 can also effectively resist lateral wind disturbance.

In some application scenarios, multiple nozzles 221 and multiple communication holes 232 are arranged in one-to-one correspondence to take into account the uniformity effect and flow rate of the air flow.

In some application scenarios, the nozzle 221 and the plurality of communication holes 232 are arranged in non-one-to-one correspondence, which is conducive to secondary homogenization of the air flow. The nozzle 221 may be, but is not limited to, a circle, an ellipse, a rectangle, an irregular shape, etc. Preferably, the nozzle 221 is circular.

Further, the field of view baffle 1 also includes an airflow homogenizing plate 13, which is annularly arranged on the field of view baffle body 11, and the height of the upper end surface of the airflow homogenizing plate 13 is not less than the height of the nozzle 221, so as to The airflow ejected from the nozzle 221 is made to meet the front surface of the airflow equalizing plate 13, so that the airflow ejected from the nozzle 221 is further homogenized, and the degree of uniformity of the airflow is improved.

Furthermore, an airflow baffle 24 extending toward the center is circumferentially provided on the annular main structure 2 on the side of the nozzle 221 away from the field of view baffle 1 . The lower end surface of the airflow baffle 24 and the upper end surface of the airflow homogenizing plate 13 There is a gap between them, which is used to create an air curtain protective layer, so that the outgoing air flow state is in a laminar flow state, ensuring the cleanliness of the lens surface.

The air flow baffle 24 is annular in shape. The shape of the airflow baffle 24 can be set according to the homogenization requirements. Preferably, the airflow baffle 24 is annular in shape.

For example, the field of view baffle body 11 is a circular plate-shaped structure, and the airflow baffle 24 and the field of view baffle 11 are parallel to each other.

Moreover, the airflow baffle 24 and the annular main structure 2 are integrated structures to enhance the structural strength.

Further, as shown in Figure 6, the field of view baffle 1 also includes an air flow guide plate 14. The air flow equalizing plate 13 and the air flow guide plate 14 are both annularly arranged on the same side of the field of view baffle body 11, and the air flow is uniform. The chemical plate 13 and the field baffle body 11 are arranged at a first preset angle B, and the airflow guide plate 14 and the field baffle body 11 are arranged at a second preset angle C. Specifically, the first preset included angle B is the included angle between the airflow equalizing plate 13 and the plane of the left part of the field of view baffle body 11; the second preset included angle C is the included angle between the airflow guide plate 14 and the field of view baffle body 11. The angle between the planes of the right part of the baffle body 11. The range of the first preset included angle B is 0-180°, and the range of the second preset included angle C is 0-180°.

The angle between the airflow homogenizing plate 13 and the field baffle body 11 is rounded or sharp, which facilitates adjusting the flow of airflow and reducing flow resistance.

Further, as shown in FIGS. 3 and 6 , the airflow equalizing plate 13 extends obliquely in the direction close to the nozzle 221 , and the first preset angle B between the airflow equalizing plate 13 and the field of view baffle body 11 is 25°-85°. Preferably, the first preset angle B between the airflow equalizing plate 13 and the field of view baffle body 11 is 60-75°. Through the mutual cooperation of the air flow homogenizing plate 13, the air flow baffle 24, and the air flow guide plate 14, the vortex caused by the uneven distribution of flow speed in the accommodation cavity 21 is avoided, so that anti-pollution and lateral resistance are generated in the device accommodation cavity 21. Disturbed clean gas shield.

Further, as shown in FIGS. 3 and 6 , the airflow guide plate 14 extends obliquely in a direction away from the nozzle 221 , and the second preset angle C between the airflow guide plate 14 and the field of view baffle body 11 is 25°-40°. Preferably, the second preset included angle C between the airflow guide plate 14 and the plane of the field baffle body 11 is in the range of 27°-38°. In other embodiments, the height and inclination angle of the airflow deflector 14 can be changed according to the size of the gas protective layer required and the anti-lateral disturbance requirements.

Specifically, in this embodiment, the height of the air flow guide plate 14 is smaller than the height of the air flow equalizing plate 13, which facilitates the rapid convergence of the air flows. After the gas is homogenized, it flows out from the gap between the air flow baffle 24 and the air flow homogenizing plate 13. A part of the air flow flows along the air flow baffle 24 in parallel laminar flow, and the other part of the air flow follows the back of the air flow homogenizing plate 13 and the field of view baffle body 11. The upper surface and the back side of the airflow guide plate 14 flow, and then the two parts of the airflow merge, making the outgoing air flow state in a laminar flow state, and finally flows out from the field of view window 12 . Installing the anti-pollution protection device on the optical glass can form a protective gas layer that can resist lateral disturbance on the surface of the optical glass to be protected.

Specifically, the gap between the airflow baffle 24 and the airflow equalizing plate 13 is set to 0.5mm-2mm. Preferably, the gap between the airflow baffle 24 and the airflow homogenizing plate 13 needs to be set within 1 mm to 1.5 mm to ensure that the outlet air flow rate is fully uniformly distributed.

The field of view window 12 can select openings of different shapes according to optical design requirements. In some application scenarios, as shown in FIG. 7 , the shape of the field of view window 12 is a square. In other application scenarios, as shown in FIG. 8 , the shape of the field of view window 12 is a rectangle. The field of view window 12 is adapted to the emission line of the optical glass without any obstruction.

Further, as shown in FIG. 2 , the first powder cleaning hole 3 is provided through the outer annular wall of the second annular channel 23 . Furthermore, as shown in FIG. 9 , the first annular channel 22 is provided with a second powder cleaning hole 4 . During the use of the anti-pollution protection device, both the first powder cleaning hole 3 and the second powder cleaning hole 4 are in a blocked state. After using the anti-pollution protection device for a certain period of time, connect the air gun to the first powder cleaning hole 3 and the second powder cleaning hole 4 to blow out the sediment or dust inside the anti-pollution protection device to complete the cleaning work.

Specifically, the second annular channel 23 is provided with a first powder cleaning hole 3, and two spaced apart second powder cleaning holes 4 are provided below the first annular channel 22.

Further, as shown in Figures 2 and 9, the first annular channel 22 is provided with a first mounting hole 5, and the field of view baffle body 11 is provided with a second mounting hole 6. The first mounting hole 5 and the second mounting hole are 6 is arranged correspondingly, and the field baffle body 11 is connected to the first mounting hole 5 using fasteners. Specifically, the first mounting hole 5 is a threaded hole. A plurality of first mounting holes 5 are provided. Specifically, four first mounting holes 5 are provided, and the four first mounting holes 5 are evenly spaced below the first annular channel 22 .

Further, as shown in FIG. 9 , the first mounting hole 5 and the second cleaning hole 4 are located on the same side of the first annular channel 22 . As shown in FIG. 2 , a blocking head 7 is protruding from the field baffle body 11 , and the blocking head 7 is provided correspondingly to the second powder cleaning hole 4 . When the field baffle body 11 is installed on the annular main structure 2 , the blocking head 7 is sealingly inserted into the second cleaning hole 4 .

This embodiment also provides an objective lens, which includes an objective lens and the above-mentioned anti-pollution protection device. The objective lens is arranged on a side of the annular main structure 2 away from the field of view baffle 1 , and the objective lens is coaxially arranged with the field of view window 12 , avoid blocking light, and improve the cleanliness of the objective lens surface through the protective gas layer formed in the accommodation cavity 21 that is fully homogenized and resistant to lateral disturbance.

This embodiment also provides a photolithography machine, which includes the above anti-pollution protection device. The field of view window 12 is a rectangular opening, and the anti-pollution protection device is detachably connected to the objective lens.

The principle of this device is that Clean Dry Gas (CDA) first flows into the second annular channel 23 from the air inlet 231. The flow direction changes and is evenly distributed in the flow channel. Through the multiple communication holes 232, the uneven aperture is Distributed to produce a uniform outlet flow rate, it flows into the first annular channel 22. The first annular channel 22 passes through the nozzle 221 with uneven aperture distribution and the air flow homogenizing plate 13 to further homogenize the outlet air flow rate. To ensure the air outlet flow rate, the outlet air flow rate of the nozzle 221 after optimization should remain within the range of 0.7m/s-1m/s, and the number of internal holes and the inlet air flow rate should be set within this range. The design of the mutual cooperation between the second annular channel 23, the first annular channel 22 and the air flow homogenizing plate 13 ensures the uniform distribution of the outlet air flow rate to the greatest extent on the basis of ensuring the outlet air flow rate, and makes the outlet air flow state in a laminar flow state, thereby forming Air shield against lateral disturbances. At the same time, positive pressure gas is generated in the containment chamber 21 to ensure that pollutants are difficult to enter the interior of the device. Under the condition of lateral disturbance, the semi-enclosed containment chamber 21 is the design theoretical basis for the device to effectively maintain the anti-pollution performance of the device (so that Optical glass surface contamination is maintained below 0.5%).

Note that the above are only the preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here, and that various obvious changes, readjustments and substitutions can be made to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the present invention The scope is determined by the scope of the appended claims.

Claims (14)

1. An anti-pollution protection device, characterized in that it includes: The annular main structure (2) includes an accommodation cavity (21), a first annular channel (22) and a second annular channel (23) arranged sequentially from the inside to the outside. The outer wall of the second annular channel (23) is penetrated with The air inlet (231), the second annular channel (23) communicates with the first annular channel (22), the first annular channel (22) communicates with the accommodation cavity (21), the accommodation cavity (21) The cavity (21) penetrates the annular main structure (2) along the axial direction of the first annular channel (22); The field of view baffle (1) is provided in the accommodation cavity (21) and connected to the annular main structure (2). The field of view baffle (1) includes a field of view baffle body (11), so A field of view window (12) is provided on the field of view baffle body (11), and the field of view window (12) penetrates the field of view baffle body (11) along the axial direction of the first annular channel (22). ). 2. The anti-pollution protection device according to claim 1, characterized in that the second annular channel (23) is provided with a plurality of communicating holes (232) at circumferential intervals, and the second annular channel (23) It communicates with the first annular channel (22) through the communication hole (232). 3. The anti-pollution protection device according to claim 2, characterized in that the communication hole (232) and the air inlet (231) are arranged non-coaxially. 4. The anti-pollution protection device according to claim 1, characterized in that the first annular channel (22) is provided with a plurality of nozzles (221) circumferentially spaced, and the first annular channel (22) passes through The nozzle (221) is connected with the accommodation chamber (21). 5. The anti-pollution protection device according to claim 4, characterized in that the field of view baffle (1) also includes an air flow homogenizing plate (13), the air flow homogenizing plate (13) is annularly arranged on the On the field of view baffle body (11), the airflow homogenizing plate (13) and the field of view baffle body (11) are arranged at a first preset angle B, and the airflow homogenizing plate (13) The height of the upper end surface is not less than the height of the nozzle (221). 6. The anti-pollution protection device according to claim 5, characterized in that the angle between the airflow homogenizing plate (13) and the field baffle body (11) is a rounded corner or a sharp corner. 7. The anti-pollution protection device according to claim 5, characterized in that, on the annular main structure (2), the nozzle (221) is circumferentially located on the side away from the field of view baffle (1). An airflow baffle (24) extending toward the center is provided, and there is a gap between the lower end surface of the airflow baffle (24) and the upper end surface of the airflow equalizing plate (13). 8. The anti-pollution protection device according to claim 5 or 7, characterized in that the field of view baffle (1) also includes an air flow guide plate (14), the air flow guide plate (14) is arranged in an annular shape On the field of view baffle body (11), the airflow deflector (14) and the field of view baffle body (11) are arranged at a second preset angle C, and the airflow deflector ( The height of 14) is smaller than the height of the air flow homogenizing plate (13). 9. The anti-pollution protection device according to claim 8, characterized in that the air flow homogenizing plate (13) extends obliquely in a direction close to the nozzle (221), and the air flow homogenizing plate (13) The first preset angle B with the field baffle body (11) is 25°-85°. 10. The anti-pollution protection device according to claim 8, characterized in that the air flow guide plate (14) extends obliquely in a direction away from the nozzle (221), and the air flow guide plate (14) The second preset angle C with the field baffle body (11) is 25°-40°. 11. The anti-pollution protection device according to claim 1, characterized in that the outer annular wall of the second annular channel (23) is provided with a first powder cleaning hole (3), and the first annular channel (23) is provided with a first powder cleaning hole (3). 22) is provided with a second powder cleaning hole (4). 12. The anti-pollution protection device according to claim 2, characterized in that the air inlet (231) extends along the radial direction of the second annular channel (23). 13. An objective lens, characterized in that it includes an objective lens and an anti-pollution protection device as claimed in any one of claims 1 to 12, the objective lens being arranged on the annular main structure (2) away from the field of view baffle (1) ) side, and the objective lens is coaxially arranged with the field of view window (12). 14. A photolithography machine, characterized by comprising the objective lens according to claim 13.