Non-contact wafer stage cleaning device, method, and cleaning inspection device and method thereof

Abstract

The present invention discloses a non-contact cleaning device and method for a wafer stage, and a cleaning inspection device and method thereof. The cleaning device is located directly above the wafer stage. The cleaning device includes a blowing nozzle and a shielding cover circumferentially arranged around the blowing nozzle. The projection position of the shielding cover and the blowing nozzle on the wafer stage is located within the projection position of the wafer on the wafer stage. The present invention uses a non-contact method to clean the wafer stage, avoiding abrasion of the wafer stage. After cleaning, there is no need to use a bare wafer for verification. With the solution of the present invention, the cleanliness of the wafer stage can be confirmed immediately.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor wafer processing, and particularly to a non-contact wafer stage cleaning device, method, cleaning inspection device and method thereof. Background Art

[0002] Before a wafer enters a lithography machine, unwanted contaminants often remain on the back surface. During the exposure process of the wafer, these contaminants will fall off and adhere to the surface of the wafer stage, reducing the cleanliness of the wafer stage. Moreover, the contaminants may transfer to the back surface of the next wafer placed on the wafer stage, expanding the contamination range of the wafer. These contaminants will also reduce the flatness of the wafer stage, causing defocusing during the exposure process of the wafer and affecting product quality. After long-term accumulation of these contaminants, it may also cause damage to the expensive wafer stage, resulting in waste of resources.

[0003] The traditional cleaning method for the wafer stage is to use a manual stone or a dust-free tool to handle it.

[0004] When using a manual stone to grind the wafer stage, the manual stone is pushed outwards for cleaning. During the process of the contaminating particles moving around, it is extremely easy for them to remain between the pins of the wafer stage and cannot be completely removed. When using a dust-free tool such as an ear syringe, it also requires manual cleaning, and the cleaning efficiency is low. Even after cleaning, a bare wafer is needed to verify whether the contaminating particles have been removed.

[0005] Due to the contamination on the back surface of the wafer, contaminating particles enter the wafer stage on the lithography scanner device, resulting in the problem of local focus. Although the pre-cleaning back surface treatment process is also following the cleaning, due to the presence of contaminating particles and wafer water droplets, the problem of local focus still continues to occur. As a result, defective wafers must be reworked.

[0006] Because of the contaminating particles and wafer water droplets, the wafer stage is contaminated. Even if manual cleaning or automatic cleaning is carried out, the contaminating particles cannot be completely removed. Since the local focus tool cleans by contacting the wafer stage, it will also cause wear on the wafer stage. And after cleaning, it is necessary to use a bare wafer again to verify whether it is cleaned, and the verification operation is cumbersome. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that the prior art using manual stone scrubbing or dust-free tool blowing cannot effectively ensure the cleanliness of the wafer stage, and the cleaning efficiency is low, and the verification operation is cumbersome. The purpose is to provide a non-contact wafer stage cleaning device, method, cleaning inspection device and method thereof, which solves the problems of improving the cleaning efficiency and cleanliness of the wafer stage and quickly verifying the cleanliness.

[0008] The present invention is achieved by the following technical solutions:

[0009] First solution, a non-contact wafer stage cleaning device, the cleaning device is located directly above the wafer stage, the cleaning device includes a blowing nozzle, and a shielding cover circumferentially arranged around the blowing nozzle, and the projection position of the shielding cover and the blowing nozzle on the wafer stage is located within the projection position of the wafer on the wafer stage.

[0010] The principle of the non-contact wafer stage cleaning device of the present invention is as follows: automatically blow air towards the wafer stage through the blowing nozzle, so that the contamination particles in the gaps between the pins of the wafer stage chuck move in a jumping motion towards the circumference of the wafer stage along the direction of the air flow. During the upward jumping process of the contamination particles, they are blocked by the shielding cover located above the wafer stage and fall back onto the wafer stage. Then, driven by the air flow again, they move towards the four sides of the wafer stage and finally move out of the wafer stage, achieving the effect of automatically cleaning the wafer stage.

[0011] In the traditional methods, such as manual stone scrubbing or manual blowing with a dust-free tool, it is very difficult to completely clean the contamination particles in the gaps between the pins of the wafer stage chuck, and the cleaning speed is relatively slow, mainly depending on the proficiency of the operator. In the solution of the present invention, the contamination particles in each gap are driven by the air flow to move away from the wafer circumference table, realizing contactless cleaning, with good cleaning effect and high efficiency, and being suitable for industrial applications.

[0012] Further, the shielding cover is circumferentially presented as an annular convex groove, and the concave surface of the annular convex groove faces the wafer stage; the outer circumference of the annular convex groove away from the blowing nozzle forms the outer edge surface of the shielding cover, and the included angle range between the outer edge surface and the inner bottom surface of the annular convex groove is 90 degrees - 180 degrees.

[0013] Further, the included angle between the outer edge surface and the inner bottom surface of the annular convex groove is 135 degrees.

[0014] Further, a dust collection port is arranged on the side wall surface of the outer edge surface close to the blowing nozzle. Driven by the movement of the air flow, the contamination particles jump and scatter between the shielding cover and the wafer stage, and the contamination particles are collected through the dust collection port on the outer edge surface, avoiding the contamination particles from drifting into the air and polluting other equipment, achieving the purpose of dust collection.

[0015] Further, the connecting part of the annular convex groove close to the blowing nozzle forms a step protruding towards the wafer stage.

[0016] Further, the projection position of the blowing nozzle on the wafer stage and the projection position of the wafer on the wafer stage are concentric. To ensure that the air flow pressure blown out by the blowing nozzle just acts on the central position of the wafer stage, so that the air flow movement speeds at each position on the circumference of the wafer stage are balanced, and the contamination particles at each position on the wafer stage can be effectively processed.

[0017] Second solution: non-contact wafer stage cleaning method. Using the above non-contact wafer stage cleaning device, a moving air flow with a constant and controllable speed is blown onto the wafer stage through the air blowing nozzle. Under the action of the moving air flow, the contamination particles on the wafer stage drift from the center of the wafer stage to the periphery and leave the wafer stage.

[0018] Third solution: non-contact wafer stage cleaning inspection device. The inspection device is used to perform cleanliness inspection on the wafer stage cleaned by the above non-contact wafer stage cleaning method. The inspection device includes: a sampling gas volume channel is arranged on the side wall of the air blowing nozzle; a reference nozzle is arranged, and a reference gas volume channel is arranged on the side wall of the reference nozzle. A reference workbench without contamination particles is arranged at the position directly opposite to the reference nozzle; the sampling gas volume channel and the reference gas volume channel are connected to both ends of a differential pressure sensor, and the differential pressure sensor is used to measure the pressure difference of the gas in the sampling gas volume channel and the reference gas volume channel; the sampling gas volume channel and the reference gas volume channel are arranged in a mirror image, the air blowing nozzle and the reference nozzle are arranged in a mirror image, and the gas volume speeds sent to the air blowing nozzle and the reference nozzle are equal, and the position of the reference workbench and the wafer stage are arranged in a mirror image.

[0019] In the prior art, to verify whether the wafer stage is clean, a bare wafer is placed on the wafer stage to be measured, and then the bare wafer is scanned by a computer to determine whether the bare wafer is contaminated, so as to indirectly judge the cleanliness of the wafer stage to be measured. The inspection device of the third solution of the present invention is integrally arranged on the basis of the first solution of the present invention, and inspection and cleaning are carried out synchronously. Through the pressure sensing detection of the sampling gas volume and the reference gas volume of the air blowing nozzle, an effective and accurate measurement of the cleanliness of the wafer stage to be measured is achieved.

[0020] Further, the same air supply pipeline is evenly divided into two identical branch pipelines, and the two branch pipelines are respectively connected to the air blowing nozzle and the reference nozzle.

[0021] Fourth solution, a non-contact cleaning and inspection method for a wafer stage, uses the above non-contact cleaning and inspection device for the wafer stage to perform cleanliness inspection. The inspection method includes: the differential pressure sensor judges according to the pressure difference of the gases in the sampling gas volume channel and the reference gas volume channel; when the pressure of the sampling gas volume flux is less than the pressure of the reference gas volume channel and the pressure difference is greater than a preset threshold, it indicates that the cleanliness of the wafer stage does not meet the production requirements, and the wafer stage is cleaned again; when the pressure of the sampling gas volume flux is greater than the pressure of the reference gas volume channel, it indicates that the reference workbench is contaminated, and the reference workbench is replaced; when the pressure of the sampling gas volume flux is less than or equal to the pressure of the reference gas volume channel and the pressure difference is less than the preset threshold, it indicates that the cleanliness of the wafer stage meets the production requirements.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] The present invention uses a non-contact method to clean the wafer stage, avoiding abrasion of the wafer stage; after cleaning, there is no need to use a bare wafer for verification, and the cleanliness of the wafer stage can be immediately confirmed by using the solution of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0025] Figure 1 is a schematic structural diagram of Embodiment 1;

[0026] Figure 2 is a schematic structural diagram of Embodiment 3.

[0027] Marks in the drawings and corresponding component names:

[0028] 1 - wafer stage, 2 - blowing nozzle, 3 - shielding cover, 31 - outer edge surface, 32 - dust collection port, 33 - annular convex groove, 34 - step, 4 - contamination particle; 5 - reference nozzle, 6 - reference gas volume channel, 7 - sampling gas volume channel, 8 - pressure reducing sensor, 9 - reference workbench. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0030] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those of ordinary skill in the art that: the present invention may be practiced without these specific details. In other instances, well-known structures, circuits, materials, or methods have not been specifically described to avoid obscuring the understanding of the present invention.

[0031] Throughout the specification, the reference to "an embodiment", "embodiment", "an example" or "example" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. Thus, the phrases "an embodiment", "embodiment", "an example" or "example" appearing throughout the specification do not necessarily all refer to the same embodiment or example. In addition, the specific features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art should understand that the diagrams provided herein are for illustrative purposes only and are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0032] In the description of the present invention, the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention.

[0033] During the wafer processing, the wafer stage is used to support the wafer, and the cleanliness of the wafer stage directly affects the cleanliness of the wafer. A chuck is provided on the wafer stage, and pins are provided on the chuck. A plurality of pins together are used to support the wafer. It is easy to hide many contamination particles in the gaps between the pins, and these contamination particles are located in the gaps between the pins. The traditional wafer stage cleaning method fails to effectively clean the contamination particles in these gaps.

[0034] Embodiment 1

[0035] This Embodiment 1 is a non-contact wafer stage cleaning device, as Figure 1As shown in the figure, the cleaning device is located directly above the wafer stage 1. The cleaning device includes a blowing nozzle 2 and a shielding cover 3 circumferentially arranged around the blowing nozzle 2. The projection position of the shielding cover 3 and the blowing nozzle 2 on the wafer stage 1 is within the projection position of the wafer on the wafer stage 1.

[0036] The principle of the non-contact wafer stage cleaning device of Embodiment 1 is as follows: The blowing nozzle 2 automatically blows air towards the wafer stage 1, causing the contamination particles 4 in the gaps between the pins of the chuck of the wafer stage 1 to jump circumferentially towards the wafer stage 1 along the direction of the airflow. During the upward jump of the contamination particles 4, they are blocked by the shielding cover 3 located above the wafer stage 1 and fall back onto the wafer stage 1. Then, again driven by the airflow, they move towards the four sides of the wafer stage 1 and finally move out of the wafer stage 1, achieving the effect of automatically cleaning the wafer stage 1.

[0037] In traditional cleaning methods, such as manual scrubbing with a stone or manual cleaning with a dust-free tool or blowing with a rubber bulb, it is very difficult to completely clean the contamination particles 4 in the gaps between the pins of the chuck of the wafer stage 1, and the cleaning speed is relatively slow, mainly depending on the proficiency of the operator. In the solution of Embodiment 1, the contamination particles 4 in each gap are driven by the airflow ejected from the jet nozzle 2 to move, and the contamination particles 4 are carried away from the wafer stage 1, realizing non-contact cleaning, with good cleaning effect and high efficiency, which is suitable for industrial promotion and application.

[0038] In a possible embodiment, the shielding cover 3 presents a circumferential annular convex groove 33, and the concave surface of the annular convex groove 33 faces the wafer stage 1; the outer peripheral of the annular convex groove 33 away from the blowing nozzle 2 forms the outer edge surface 31 of the shielding cover 3, and the included angle range between the outer edge surface 31 and the inner bottom surface of the annular convex groove 33 is 90 degrees - 180 degrees. In a better solution, the included angle between the outer edge surface 31 and the inner bottom surface of the annular convex groove 33 can be set to 135 degrees. At this angle, the movement range of the contamination particles 4 can be well controlled to avoid drifting into the air.

[0039] In a possible embodiment, a dust collection port 32 is provided on the side wall surface of the outer edge surface 31 close to the blowing nozzle 2. Driven by the airflow movement, the contamination particles 4 jump and scatter between the shielding cover 3 and the wafer stage 1, and the contamination particles 4 are collected through the dust collection port 32 on the outer edge surface 31, avoiding the contamination particles 4 from drifting into the air and contaminating other equipment, achieving the purpose of dust collection.

[0040] In a possible embodiment, the connecting part of the annular convex groove 33 close to the blowing nozzle 2 forms a step 34 protruding towards the wafer stage 1. Driven by the airflow blown out by the blowing nozzle 2, the contamination particles 4 move along the step 34, the annular convex groove 33, and the outer edge surface 31 in sequence and enter the dust collection port 32, avoiding the outer scattering of the contamination particles 4 into the air and affecting other equipment.

[0041] In a possible embodiment, the projection position of the blowing nozzle 2 on the wafer stage 1 is concentric with the projection position of the wafer on the wafer stage 1. This ensures that the air flow pressure blown by the blowing nozzle 2 just acts on the central position of the wafer stage 1, making the air flow movement speeds at all positions in the circumferential direction of the wafer stage 1 balanced, so that the contamination particles 4 at all positions on the wafer stage 1 can be effectively cleaned.

[0042] Embodiment 2

[0043] This Embodiment 2 is a method for cleaning a wafer stage by using the non-contact wafer stage cleaning device of Embodiment 1. Specifically, a moving air flow with a constant and controllable speed is blown onto the wafer stage through a blowing nozzle. Under the action of the moving air flow, the contamination particles on the wafer stage drift from the center of the wafer stage to the surroundings and leave the wafer stage, achieving non-contact cleaning of the wafer stage. The air volume and speed of the blowing nozzle can be manually controlled according to devices such as air pumps in the prior art.

[0044] Embodiment 3

[0045] This Embodiment 3 is a non-contact wafer stage cleaning and inspection device. The inspection device is used to inspect the cleanliness of the wafer stage that has been cleaned by the non-contact wafer stage cleaning method in Embodiment 2. As Figure 2 shown, the part within the dashed box is the cleaning device in Embodiment 1, that is Figure 1 shown. The inspection device of this Embodiment 3 includes: a sampling air volume channel 7 is arranged on the side wall of the blowing nozzle 2; a reference nozzle 5 is arranged, a reference air volume channel 6 is arranged on the side wall of the reference nozzle 5, and a reference workbench 9 without contamination particles is arranged at the position directly opposite to the reference nozzle 5; the sampling air volume channel 7 and the reference air volume channel 6 are connected to both ends of a differential pressure sensor 8, and the differential pressure sensor 8 is used to measure the pressure difference between the gases in the sampling air volume channel and the reference air volume channel; the sampling air volume channel 7 and the reference air volume channel 6 are mirror-symmetrically arranged, the blowing nozzle 2 and the reference nozzle 5 are mirror-symmetrically arranged, and the air volume speed sent to the blowing nozzle 2 and the air volume speed sent to the reference nozzle 5 are equal, and the position of the reference workbench 1 and the wafer stage 1 are mirror-symmetrically arranged.

[0046] In the prior art, for verifying whether a wafer stage is clean, a bare wafer is placed on the wafer stage to be measured, and then the bare wafer is scanned by a computer to determine whether the bare wafer is contaminated, thereby indirectly determining the cleanliness of the wafer stage to be measured. The inspection device of this Embodiment 3, on the basis of Embodiment 1, further sets an integrated setting to synchronize the inspection operation of the wafer stage with the cleaning operation of the wafer stage, and can monitor the cleaning process of the wafer stage in real time. By detecting the pressure sensation of the sampling air volume and the reference air volume of the blowing nozzle, an effective and accurate measurement of the cleanliness of the wafer stage to be measured is achieved.

[0047] In a possible embodiment, the same air supply pipeline is evenly divided into two identical branch pipelines, and the two branch pipelines are respectively connected to the blowing nozzle and the reference nozzle, ensuring that the gas volume composition, gas volume velocity, and gas volume pressure in the two branch pipelines are equal.

[0048] Embodiment 4

[0049] Embodiment 4 is a non-contact wafer stage cleaning and inspection method based on Embodiment 3. The non-contact wafer stage cleaning and inspection device of Embodiment 3 is used to perform cleanliness inspection on the cleaned wafer stage. The inspection method of Embodiment 4 includes: the differential pressure sensor judges according to the pressure difference between the gases in the sampled gas volume channel and the reference gas volume channel; when the pressure of the sampled gas volume flux is less than the pressure of the reference gas volume channel, and the pressure difference is greater than the preset threshold, it indicates that the cleanliness of the wafer stage does not meet the production requirements, and the wafer stage needs to be cleaned again; when the pressure of the sampled gas volume flux is greater than the pressure of the reference gas volume channel, it indicates that the reference workbench is contaminated, and the reference workbench needs to be replaced; when the pressure of the sampled gas volume flux is less than or equal to the pressure of the reference gas volume channel, and the pressure difference is less than the preset threshold, it indicates that the cleanliness of the wafer stage meets the production requirements.

[0050] The working principle of Embodiment 4 is as follows: If there are contamination particles (Particles) on the wafer stage, the gas volume blown into the wafer stage from the blowing nozzle 7 will be blocked by the contamination particles, thereby affecting the flow velocity of the gas volume, resulting in a change in the gas volume pressure of the sampled gas volume pipeline 7. Since the reference workbench is a clean standard reference quantity and there are no contamination particles on the reference workbench, the gas volume blown into the reference workbench 9 from the reference nozzle 5 is constant, making the gas volume pressure of the reference gas volume channel 6 also constant. The gas volume pressure of the sampled gas volume pipeline 7 is compared and judged with the gas volume pressure of the reference gas volume channel 6 through the differential pressure sensor 8. If the gas volume pressure of the sampled gas volume pipeline 7 is less than the gas volume pressure of the reference gas volume channel 6, it indicates that there are contamination particles on the wafer stage and further cleaning is required. If the gas volume pressure of the sampled gas volume pipeline 7 is equal to the gas volume pressure of the reference gas volume channel 6, it indicates that there are no contamination particles on the wafer stage and it is clean. It should be noted that those skilled in the art should know that the "less than" or "equal to" here is not an absolute magnitude comparison, but a comparison within a predetermined range. According to the actual production needs, a threshold range can be set. When the pressure difference is within the threshold range, it indicates that the cleanliness of the wafer stage meets the requirements. When the pressure difference is outside the threshold range, it indicates that there are contamination particles on the wafer stage and its cleanliness does not meet the production requirements.

[0051] Meanwhile, the fourth embodiment of the present invention can also be used to determine whether the reference workbench 9 is contaminated. When the gas pressure in the sampling gas pipeline 7 is greater than the gas pressure in the reference gas passage 6, it indicates that the gas volume of the reference nozzle 5 is blocked by contaminated particles. At this time, the reference workbench 9 is contaminated and needs to be replaced. That is to say, the solution of the fourth embodiment of the present invention can be used to reversely check whether the reference workbench is contaminated. Of course, when the reference workbench is completely clean and not contaminated, the gas pressure in the sampling gas pipeline 7 must be greater than or equal to the gas pressure in the reference gas passage 6.

[0052] The present invention uses a non-contact method to clean the wafer stage. During the cleaning process, the cleaning device does not directly contact the wafer stage. Only the airflow movement is used to drive the contaminated particles in the gap to move outside the wafer stage, avoiding abrasion of the wafer stage. And after cleaning, there is no need to use a bare wafer for verification. With the solution of the present invention, the cleanliness of the wafer stage can be confirmed immediately, realizing the synchronous progress of cleaning and inspection. In the wafer stage cleaning link, the time of the entire wafer processing flow is saved.

[0053] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Non-contact wafer stage cleaning inspection device, characterized in that, the inspection device is used to inspect the cleanliness of a wafer stage cleaned by a non-contact wafer stage cleaning method; the non-contact wafer stage cleaning method uses a non-contact wafer stage cleaning device; the cleaning device is located directly above the wafer stage. The cleaning device includes a blowing nozzle and a shielding cover circumferentially arranged around the blowing nozzle. The projection position of the shielding cover and the blowing nozzle on the wafer stage is within the projection position of the wafer on the wafer stage; the non-contact wafer stage cleaning method is: blowing a moving air flow with a constant and controllable speed through the blowing nozzle to the wafer stage. Under the action of the moving air flow, the contamination particles on the wafer stage drift from the center of the wafer stage to the surroundings and leave the wafer stage; the inspection device includes: a sampling gas volume channel is arranged on the side wall of the blowing nozzle; a reference nozzle is arranged, a reference gas volume channel is arranged on the side wall of the reference nozzle, and a reference workbench without contamination particles is arranged at the position directly opposite to the reference nozzle; the sampling gas volume channel and the reference gas volume channel are connected to both ends of a differential pressure sensor, and the differential pressure sensor is used to measure the pressure difference between the gases in the sampling gas volume channel and the reference gas volume channel; the sampling gas volume channel and the reference gas volume channel are mirror-symmetrically arranged, the blowing nozzle and the reference nozzle are mirror-symmetrically arranged, and the gas volume speeds sent to the blowing nozzle and the reference nozzle are equal, and the position of the reference workbench and the wafer stage are mirror-symmetrically arranged; wherein, the shielding cover presents an annular convex groove circumferentially, and the concave surface of the annular convex groove faces the wafer stage; the outer peripheral of the annular convex groove away from the blowing nozzle forms the outer edge surface of the shielding cover, and the included angle range between the outer edge surface and the inner bottom surface of the annular convex groove is 90 degrees - 180 degrees.

2. The non-contact wafer stage cleaning inspection device according to claim 1, characterized in that, the included angle between the outer edge surface and the inner bottom surface of the annular convex groove is 135 degrees.

3. The non-contact wafer stage cleaning inspection device according to claim 1, characterized in that, a dust collection port is arranged on the side wall surface of the outer edge surface close to the blowing nozzle.

4. The non-contact wafer stage cleaning inspection device according to claim 1, characterized in that, a step convex towards the wafer stage is formed at the connecting part of the annular convex groove close to the blowing nozzle.

5. The non-contact wafer stage cleaning inspection device according to claim 1, characterized in that, the projection position of the blowing nozzle on the wafer stage and the projection position of the wafer on the wafer stage are concentric.

6. The non-contact wafer stage cleaning inspection device according to claim 1, characterized in that, the same air supply pipeline is divided into two identical branch pipelines, and the two branch pipelines are respectively connected to the blowing nozzle and the reference nozzle.

7. Non-contact wafer stage cleaning inspection method, characterized in that, using the non-contact wafer stage cleaning inspection device according to any one of claims 1 - 6 to inspect the cleanliness of the cleaned wafer stage, the inspection method includes: The differential pressure sensor makes a judgment based on the pressure difference between the gases in the sampled gas volume channel and the reference gas volume channel; When the pressure in the sampled gas volume channel is less than the pressure in the reference gas volume channel, and the pressure difference is greater than a preset threshold, it indicates that the cleanliness of the wafer stage does not meet the production requirements, and the wafer stage is cleaned again; When the pressure in the sampled gas volume channel is greater than the pressure in the reference gas volume channel, it indicates that the reference workbench is contaminated, and the reference workbench is replaced; when the pressure in the sampled gas volume channel is less than or equal to the pressure in the reference gas volume channel, and the pressure difference is less than the preset threshold, it indicates that the cleanliness of the wafer stage meets the production requirements.

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