A wafer in-situ anomaly monitoring system and method

Abstract

The present invention discloses a wafer in-situ abnormality monitoring system, which includes a cavity and a stage for arranging wafers. The cavity has an intake valve and a vacuum pump to form the cavity pressure inside the cavity. The vacuum pump is also connected to the stage through a pipeline to form a vacuum pumping hole area on the upper surface of the stage. The vacuum pumping hole area matches and adheres to the back surface of the wafer to form a wafer back surface pressure. When the back surface of the wafer is adsorbed during the cavity pressure increase and vacuum pumping, the change of the wafer back surface pressure is fed back to judge whether there is an abnormality in the wafer position. Through this application, it is realized to judge whether there is an abnormality in the in-situ situation of the wafer according to the pressure feedback during wafer adsorption. The structure is simple, directly matches the wafer and cooperates to ensure the accuracy of monitoring. While protecting the wafer, the production process quality and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to wafer production equipment and processes, and particularly to a wafer in-situ anomaly monitoring system and method. Background Art

[0002] In existing semiconductor processing equipment, a wafer stage is usually used to carry wafers and perform corresponding production processes, such as controlling the wafer temperature. During the process, the accurate and reliable in-situ position of the wafer is a necessary prerequisite for completing the corresponding production process and ensuring production quality and efficiency. Accurate and reliable in-situ position should at least include: the planar X-Y axis coordinate position of the wafer on the stage plane, and the position of the wafer in the longitudinal direction Z axis of the stage. Only when the wafer matches the stage plane position and fits the stage plane in the longitudinal direction can the subsequent wafer processing process be executed, and the smooth completion of the process and the processing quality of the wafer be ensured. If the wafer slides or tilts, that is, the wafer moves on the stage plane, the processing surface of the wafer may not be in the optimal processing area, and defects such as inconsistent processes may occur in the processing area. If the wafer warps or tilts, the processing surfaces of the wafer may be at different heights, and the consistency and stability of the processing process cannot be guaranteed.

[0003] Therefore, if it is impossible to determine whether the wafer has slid, been lifted, warped, tilted, or uneven, for example, being lifted by particles on the back or an uneven air layer, or the abnormal operation of the wafer lifting mechanism resulting in the wafer not falling normally to fit the stage surface, it will lead to abnormal process results. For this reason, a real-time monitoring solution is needed to solve the problem that in existing semiconductor processing equipment, it is impossible to determine whether the wafer has slid or the back has been lifted during the process, resulting in abnormal process results. Summary of the Invention

[0004] To achieve the above technical objectives, the present invention provides a wafer in-situ anomaly monitoring system, which includes a chamber for performing process production and a stage inside the chamber for arranging wafers, wherein: the chamber has an intake valve and a vacuum pump to form the chamber pressure inside the chamber, the vacuum pump is also connected to the stage through a pipeline to form a vacuum hole area on the upper surface of the stage, the vacuum hole area matches and adheres to the back surface of the wafer to form a wafer back pressure, and the change of the wafer back pressure when the wafer back is adsorbed under vacuum after the chamber is pressurized is used to feedback and judge whether there is an anomaly in the wafer position, and the wafer position includes the planar arrangement position and the longitudinal arrangement position of the wafer relative to the stage.

[0005] The present invention provides a wafer in-situ anomaly monitoring system, which can judge whether there is an anomaly in the in-situ situation of the wafer according to the pressure feedback during wafer adsorption. The structure is simple and directly matches the wafer to ensure the accuracy of monitoring. While protecting the wafer, it improves the quality and efficiency of the production process.

[0006] As a further improvement, the air extraction hole region includes: a central hole located in the central area of the stage and peripheral holes located at the periphery. The central hole matches and fits with the center of the wafer, and the peripheral holes match and fit with the outer peripheral surface of the wafer. The back pressure of the wafer includes: the central air pressure in the central hole region and the peripheral air pressure in the peripheral hole region.

[0007] As a further improvement, the chamber pressure is measured and obtained by a pressure gauge module one arranged in the chamber, and the back pressure of the wafer is measured and obtained by a pressure gauge module two arranged on the stage; a central air duct is connected to the lower part of the central hole and a central air pressure gauge is arranged, and a peripheral air duct is connected to the lower part of the peripheral hole and a peripheral air pressure gauge is arranged. The central air duct and the peripheral air duct are independent of each other. The central air pressure gauge and the peripheral air pressure gauge are configured by the pressure gauge module two in the following way: they are the same common air pressure gauge and each air duct is switched by a valve, or they are independent air pressure gauges; control and monitor the changes in the chamber pressure and the back pressure of the wafer, judge the matching and fitting degree between the air extraction hole region and the back of the wafer, and further judge whether the wafer is abnormal in position, and further distinguish whether the wafer is abnormally positioned due to the back of the wafer being lifted or the wafer slipping and deviating from the central area of the stage.

[0008] As a further improvement, the peripheral holes are arranged in a circle relative to the central hole, and the diameter of the circle is smaller than the diameter of the wafer.

[0009] As a further improvement, the peripheral holes are arranged in a continuous ring on the upper surface of the stage, and the ring converges inside the stage to form the peripheral air duct.

[0010] As a further improvement, the peripheral holes have multiple holes and are symmetrically arranged relative to the central hole. The multiple holes form multiple independent peripheral air ducts inside the stage, and the multiple holes are further used to judge the deviation direction when the wafer deviates from the center.

[0011] As a further improvement, an air extraction pipeline and a decompression pipeline are connected in parallel between the air extraction pump and the inlet of the stage, and a vacuum adsorption valve and a desorption valve are respectively arranged on the air extraction pipeline and the decompression pipeline; a valve assembly is arranged on the main air extraction pipeline between the air extraction pump and the chamber, and the desorption valve is connected to the main air extraction pipeline and is connected to the air extraction pump through the valve assembly.

[0012] As a further improvement, the diameter of the circle where the peripheral holes are arranged is smaller than the diameter of the wafer by 0.5 mm to 5 mm, the high-precision of the back of the wafer being lifted is 0.05 mm to 0.1 mm, and the pressure gauge module two is arranged at the inlet of the pipeline when it enters the stage.

[0013] Correspondingly, the present invention further provides a method for on-wafer abnormal monitoring, which employs the above-mentioned on-wafer abnormal monitoring system of the present invention; it includes: controlling and monitoring the changes in the chamber pressure and the back pressure of the wafer; judging the matching and fitting degree between the evacuation hole area and the back of the wafer; further judging whether the wafer is abnormal in position; differentiating whether the abnormal position of the wafer is caused by the back of the wafer being lifted or the wafer slipping and deviating from the center area of the carrier.

[0014] As a further improvement, it at least includes the following one of the modes: Adsorption mode: evacuating the back of the wafer, and adsorbing the wafer on the surface of the carrier through the pressure difference between the front and back of the wafer. The adsorption mode includes: closing the desorption valve and opening the vacuum adsorption valve; the back pressure of the wafer when the chamber pressure rises to the target pressure; checking whether the back pressure of the wafer is less than a first threshold. If it is less, the adsorption is successful; otherwise, the adsorption fails and the wafer is abnormally positioned. Or Detection mode: evacuating the back of the wafer first and then closing the vacuum adsorption valve and the desorption valve, and checking the increase in the back pressure of the wafer. The detection mode includes: closing the desorption valve and opening the vacuum adsorption valve; waiting for the chamber pressure to rise to the target pressure and stabilizing for a certain period of time, closing the vacuum adsorption valve for a certain period of time and then opening it; the chamber pressure rises to the target pressure; checking whether the back pressure of the wafer is < a third threshold. If so, the wafer is normally positioned; otherwise, the wafer is abnormally positioned.

[0015] As a further improvement, it includes the following modes: Desorption mode: connecting the front and back of the wafer to release the adsorption of the wafer. The desorption mode includes: opening the desorption valve and closing the vacuum adsorption valve; checking whether the difference between the chamber pressure and the back pressure of the wafer is less than the second threshold. If it is less, the desorption is successful; otherwise, the desorption fails; and Idle mode: both the vacuum adsorption valve and the desorption valve are closed.

[0016] The on-wafer abnormal monitoring system and method provided by the present invention can judge whether the wafer is abnormal by the change of the back pressure of the wafer during evacuation after the chamber pressure is increased. It has four vacuum adsorption modes, and can judge whether there is a situation such as the wafer slipping, or the back being padded by particles, or the abnormal wafer lifting mechanism causing the wafer not to fall and fit the carrier surface normally, resulting in abnormal process results. It can be monitored in real time and can be applied to semiconductor plasma ashing equipment, plasma surface treatment equipment, plasma etching equipment, and thin film deposition equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the present invention;

[0018] Figure 2 Schematic diagram of the first embodiment of the air extraction hole area of the present invention;

[0019] Figure 3 Cross-sectional schematic diagram of the first embodiment of the air extraction hole area of the present invention;

[0020] Figure 4 Schematic diagram of the second embodiment of the air extraction hole area of the present invention;

[0021] Figure 5 Cross-sectional schematic diagram of the second embodiment of the air extraction hole area of the present invention;

[0022] Figure 6 Variation diagram of the test data of the present invention.

[0023] Reference numerals: cavity 1, wafer 2, stage 3, intake valve 4, air extraction pump 5, pressure gauge module one 6, pressure gauge module two 7, peripheral hole 8, central hole 9, vacuum adsorption valve 10, desorption valve 11, gas source 12, shower head 13, valve assembly 14. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] As Figures 1 to 6 shown, the wafer processing cavity 1 generally has a gas source 12, an intake valve 4, a shower head 13 and a stage. The present invention provides a wafer in-situ abnormality monitoring system, which includes a cavity 1 for performing process production and a stage 3 inside the cavity for arranging a wafer 2, wherein: the cavity has an intake valve 4 and an air extraction pump 5 and forms a cavity pressure inside the cavity, and the air extraction pump 5 is also connected to the stage through a pipeline and forms an air extraction hole area on the upper surface of the stage. The air extraction hole area matches and fits with the back surface of the wafer to form a wafer back surface pressure. When the back surface of the wafer is adsorbed under vacuum after the cavity is pressurized, the change of the wafer back surface pressure is fed back to judge whether there is an abnormality in the wafer position. The wafer position includes the planar arrangement position and the longitudinal arrangement position of the wafer relative to the stage.

[0026] The present invention provides a wafer in-situ abnormality monitoring system, which can judge whether there is an abnormality in the wafer in-situ situation according to the pressure feedback during wafer adsorption. The structure is simple, directly matches the wafer and cooperates to ensure the accuracy of monitoring. While protecting the wafer, the production process quality and efficiency are improved.

[0027] As a further improvement, the air extraction hole region includes a central hole located in the central area of the stage and peripheral holes located at the periphery. The central hole matches and adheres to the center of the wafer, and the peripheral holes match and adhere to the outer peripheral surface of the wafer. The back pressure of the wafer includes the central air pressure in the central hole region and the peripheral air pressure in the peripheral hole region.

[0028] As a further improvement, the chamber pressure is measured and obtained by a pressure gauge module 6 arranged in the chamber, and the back pressure of the wafer is measured and obtained by a pressure gauge module 7 arranged on the stage; a central air duct is connected to the lower part of the central hole 9 and a central air pressure gauge is arranged, and a peripheral air duct is connected to the lower part of the peripheral hole 8 and a peripheral air pressure gauge is arranged. The central air duct and the peripheral air duct are independent of each other. The central air pressure gauge and the peripheral air pressure gauge are configured by the pressure gauge module 7 in the following one of the configurations: being the same common air pressure gauge and each air duct is switched by a valve, or being independent air pressure gauges.

[0029] As a further improvement, control and monitor the changes in the chamber pressure and the back pressure of the wafer, judge the degree of matching and adhesion between the air extraction hole region and the back of the wafer, and further judge whether the wafer is abnormal in position, and further distinguish whether the abnormal position of the wafer is caused by the back of the wafer being raised or the wafer sliding and deviating from the central area of the stage.

[0030] As a further improvement, the peripheral holes 8 are arranged in a circle relative to the central hole 9, and the diameter of the circle is smaller than the diameter of the wafer.

[0031] As a further improvement, the peripheral holes are arranged in a continuous ring on the upper surface of the stage, and the ring converges inside the stage to form the peripheral air duct.

[0032] As a further improvement, the peripheral holes have multiple holes and are symmetrically arranged relative to the central hole. The multiple holes form multiple independent peripheral air ducts inside the stage, and the multiple holes are further used to judge the deviation direction when the wafer deviates from the center.

[0033] As a further improvement, an air extraction pipeline and a decompression pipeline are connected in parallel between the air extraction pump and the inlet of the stage. The air extraction pipeline and the decompression pipeline are respectively provided with a vacuum adsorption valve 10 and a desorption valve 11; a valve assembly 14 is arranged on the main air extraction pipeline between the air extraction pump and the chamber. The desorption valve is connected to the main air extraction pipeline and is connected to the air extraction pump through the valve assembly. The valve assembly can be realized by a butterfly valve or other components known to those skilled in the art.

[0034] As a further improvement, the circumferential diameter of the peripheral holes is less than the diameter of the wafer by 0.5 mm to 5 mm. The high precision of the backside pads of the wafer is from 0.05 mm to 0.1 mm, such as particles with a radial height of 0.05 mm to 0.1 mm, or other normal heightening. The pressure gauge module two is arranged at the inlet of the pipeline into the stage.

[0035] Correspondingly, the present invention also provides a method for monitoring wafer in - position abnormality, which adopts the above - mentioned wafer in - position abnormality monitoring system of the present invention; it includes: controlling and monitoring the changes in the chamber pressure and the backside pressure of the wafer; judging the matching and fitting degree between the air extraction hole area and the backside of the wafer; further judging whether the wafer is in - position abnormally; differentiating whether the wafer in - position abnormality is caused by the heightening of the wafer backside or the wafer slipping and deviating from the central area of the stage.

[0036] As a further improvement, it includes at least one of the following modes: adsorption mode: evacuating the backside of the wafer, and adsorbing the wafer on the surface of the stage through the pressure difference between the front and back sides of the wafer; or detection mode: first evacuating the backside of the wafer, then closing the vacuum adsorption valve and the desorption valve, and checking the increase in the backside pressure of the wafer.

[0037] As a further improvement, it includes the following modes: desorption mode: connecting the backside and the front side of the wafer to release the adsorption of the wafer; and idle mode: both the vacuum adsorption valve and the desorption valve are closed.

[0038] As a further improvement, the adsorption mode includes: closing the desorption valve and opening the vacuum adsorption valve; the backside pressure of the wafer when the chamber pressure rises to the target pressure; checking whether the backside pressure of the wafer is less than threshold one. If it is less, the adsorption is successful; otherwise, the adsorption fails and the wafer is in - position abnormally. The desorption mode includes: opening the desorption valve and closing the vacuum adsorption valve; checking whether the difference between the chamber pressure and the backside pressure of the wafer is less than threshold two. If it is less, the desorption is successful; otherwise, the desorption fails. The detection mode includes: closing the desorption valve and opening the vacuum adsorption valve; waiting for a certain time when the chamber pressure rises to the target pressure and stabilizes, closing the vacuum adsorption valve for a certain time and then opening it; the chamber pressure rises to the target pressure; checking whether the backside pressure of the wafer is < threshold three. If so, the wafer is in - position normally; otherwise, the wafer is in - position abnormally.

[0039] As a further improvement, the target pressure of the chamber pressure is greater than the backside pressure of the wafer. The backside pressure of the wafer in the detection mode is greater than the backside pressure of the wafer in the adsorption mode; the desorption time required in the desorption mode is 1 to 2 seconds; the holding time in the detection mode is 1 to 3 seconds.

[0040] As a further improvement, as the target pressure of the cavity decreases, the back pressure of the wafer in the adsorption mode and the detection mode decreases in a gradient manner, and the pressure change in the detection mode is more significant than that in the adsorption mode.

[0041] As a further improvement, the devices to which it is applied include: semiconductor plasma stripping equipment, plasma surface treatment equipment, plasma etching equipment, and thin film deposition equipment.

[0042] The in-situ abnormal monitoring system and method for wafers provided by the present invention determine whether there is an abnormality in the wafer by the change of the back pressure of the wafer during vacuum pumping after the cavity is pressurized. It has four vacuum adsorption modes and can determine whether there is a slide, or the back surface is padded with particles, or an abnormality in the wafer lifting mechanism causes the wafer not to fall normally and fit the carrier table, etc., resulting in an abnormal process result. It can be monitored in real time and can be applied to semiconductor plasma stripping equipment, plasma surface treatment equipment, plasma etching equipment, and thin film deposition equipment.

[0043] In a preferred embodiment of the present invention, an intake valve in the cavity guides a process gas source into the cavity. A first pressure gauge inside the cavity measures the cavity pressure. The cavity also has a carrier table, which generally has a lifting function and has heating and cooling functions. A wafer is arranged on the carrier table, and the wafer undergoes a process treatment in the cavity. The present invention provides an air extraction hole area on the carrier table and its air duct are connected to an air extraction pump to form the back pressure of the wafer, which is measured by arranging the pressure gauge module two at the entrance of the carrier table through a pipeline. Whether there is an abnormality in the wafer is determined by the change of the back pressure of the wafer during vacuum pumping after the cavity is pressurized. In a preferred embodiment, four vacuum adsorption modes are provided:

[0044] 1. Adsorption mode: The back surface of the wafer is evacuated, and the wafer is adsorbed on the surface of the carrier table by the pressure difference between the front and back surfaces of the wafer. In the adsorption mode, the wafer is adsorbed to the carrier table to form a pressure difference, and whether the wafer is abnormal is judged according to the pressure change. For example, when the wafer deviates, the circumferentially arranged air holes will be partially exposed and not covered by the wafer, while the central hole is still covered, and there is a difference in pressure between the two on the back surface of the wafer. The air holes of the circumferentially arranged air holes where the wafer deviates will cause a difference between the back pressure of the wafer and the standard value, thereby judging the deviation state. Similarly, when there are particles on the back of the wafer, upward gaps appear in both the central hole and the peripheral holes, which results in abnormal pressures in both of them different from the standard pressure. Therefore, whether there are abnormalities in the position and back of the wafer can be judged by the pressure during adsorption.

[0045] The adsorption mode is specifically as follows:

[0046] The desorption valve is closed and the vacuum adsorption valve is opened;

[0047] The chamber pressure P1 rises to the target pressure (such as 9 Torr, etc.), and check the backside pressure P2 of the wafer;

[0048] Check whether the backside pressure P2 of the wafer is < threshold 1: Yes, adsorption is successful, No, adsorption fails, and the wafer is abnormally positioned.

[0049] 2. Desorption mode: The backside of the wafer is connected to the front side of the wafer to release the adsorption of the wafer. After desorption, the vacuum pressure on the backside of the wafer is reduced, which is convenient for subsequent movement of the wafer from the stage without being damaged, realizing subsequent processing of the wafer.

[0050] The specific desorption mode is as follows:

[0051] The desorption valve is opened and the vacuum adsorption valve is closed;

[0052] Check whether (chamber pressure P1 - backside pressure P2 of the wafer) < threshold 2: Yes, desorption is successful, No, desorption fails.

[0053] 3. Detection mode: The backside of the wafer is first evacuated and then the vacuum adsorption valve and the desorption valve are closed, and check the increase in the backside pressure of the wafer. The detection mode is actually an improved adsorption mode, which amplifies the change rate of the adsorption mode. As shown in Table 1 and Figure 6 shown, its discrimination and difference are relatively obvious, especially when there are particles on the back of the wafer and the elevation is more obvious, and the change in pressure can be detected more accurately, and the in-position situation of the wafer can be judged with higher precision. Under the same chamber target pressure change range, the change range of the adsorption mode is relatively small, while the change range and amplitude in the detection mode are larger. In this way, it is easier to judge the in-position situation of the wafer through the detection mode, and also judge the in-position situation with higher precision, whether it is a smaller offset or a smaller particle elevation.

[0054] The specific detection mode is as follows:

[0055] The desorption valve is closed, the vacuum adsorption valve is opened, wait until the chamber pressure P1 rises to the target pressure (such as 9 Torr, etc.) and stabilizes for a certain time (such as 3 s), the vacuum adsorption valve is closed for a certain time (such as 3 s) and then opened;

[0056] The chamber pressure P1 rises to the target pressure, and check the backside pressure P2 of the wafer;

[0057] Check whether the backside pressure P2 of the wafer is < threshold 3: Yes, the wafer is in normal position, No, the wafer is abnormally positioned.

[0058] 4. Idle mode: Both the vacuum adsorption valve and the desorption valve are closed.

[0059] Table 1: Data comparison between adsorption mode and detection mode

[0060]

[0061] In a preferred embodiment of the present invention, those skilled in the art can, based on the disclosed solution of the present invention, implement corresponding automated valve operations and pressure detections, perform logical judgments on four vacuum adsorption modes, and achieve the corresponding technical effects of the present invention and its embodiments. As shown in FIG. 2 and Figure 3 is the first preferred mode of the present invention. The air extraction hole area on the carrier stage includes: a central hole in the center of the carrier stage, and a connected circular ring hole (edge air channel) around it. The circular ring air channels converge into an independent air channel inside. This design can distinguish whether the abnormal situation of the wafer in place is caused by the back of the wafer being raised or the wafer slipping and deviating from the central area. Each of the central and edge air channels corresponds to a pressure gauge (or a common pressure gauge with each channel switched by a valve). At the same time, logical judgments on four vacuum adsorption modes are performed.

[0062] Such as Figure 4 and Figure 5 In the second preferred mode, the air extraction hole area on the carrier stage includes: a central hole in the center of the carrier stage, and a plurality of independent circular holes (edge air channels) around it. The plurality of circular holes are arranged in central symmetry, and the included angle can be 15°, 30°, etc. Based on the ability to distinguish whether the abnormal situation of the wafer in place is caused by the back of the wafer being raised or the wafer slipping and deviating from the central area, this design can further determine the direction of deviation when deviating from the center. Each air channel corresponds to a pressure gauge (or a common pressure gauge with each channel switched by a valve). At the same time, logical judgments on four vacuum adsorption modes are performed.

[0063] As shown in Table 1 and Figure 6 shown, the in-place situation of the wafer can be judged according to the feedback of the back pressure P2 of the wafer during adsorption; the pressures of the adsorption mode (Chuck mode) and the detection mode (Detector mode) show a gradient change under different target pressures of the cavity; the pressure change in the detection mode (Detector mode) is more significant than that in the adsorption mode (Chuck mode).

[0064] It should be understood that the scope to be protected by the present invention is not limited to the non-restrictive embodiments, and it should be understood that the non-restrictive embodiments are only illustrative examples. The substantial scope of protection required by this application is more reflected in the scope provided by the independent claims and their dependent claims.

Claims

1. A wafer in-situ anomaly monitoring system, which includes a chamber for performing process production and a stage inside the chamber for arranging wafers, and is characterized in that: The chamber has an intake valve and a suction pump to form the chamber pressure inside the chamber. The suction pump is also connected to the stage through a pipeline to form a suction pore area on the upper surface of the stage. The suction pore area matches and adheres to the back surface of the wafer to form a wafer back pressure. The change of the wafer back pressure when the back surface of the wafer is adsorbed under vacuum after the chamber is pressurized is fed back to judge whether there is an anomaly in the wafer position. The wafer position includes the planar arrangement position and the longitudinal arrangement position of the wafer relative to the stage; A central hole located in the central area of the stage and peripheral holes located on the periphery. The central hole matches and adheres to the center of the wafer, and the peripheral holes match and adhere to the outer peripheral surface of the wafer. The wafer back pressure includes: the central air pressure in the central hole area and the peripheral air pressure in the peripheral hole area; The chamber pressure is measured and obtained by a pressure gauge module one arranged in the chamber, and the wafer back pressure is measured and obtained by a pressure gauge module two arranged in the stage; The lower part of the central hole is connected with a central air duct and a central air pressure gauge is arranged. The lower part of the peripheral hole is connected with a peripheral air duct and a peripheral air pressure gauge is arranged. The central air duct and the peripheral air duct are independent of each other. The central air pressure gauge and the peripheral air pressure gauge are configured by the pressure gauge module two in the following one of the configurations: being the same common air pressure gauge and each air duct is switched by a valve, or being independent air pressure gauges; Control and monitor the changes of the chamber pressure and the wafer back pressure, judge the matching and adhering degree between the suction pore area and the back surface of the wafer, and further judge whether the wafer is in-situ abnormally, and further distinguish whether the wafer in-situ anomaly is caused by the back surface of the wafer being lifted or the wafer slipping and deviating from the central area of the stage; The peripheral holes are arranged in a circle relative to the central hole, and the diameter of the circle is smaller than the diameter of the wafer.

2. The in-situ abnormal monitoring system for wafers according to claim 1, wherein: The peripheral holes are arranged in a continuous circular ring on the upper surface of the stage, and the circular ring converges inside the stage to form the peripheral air duct.

3. The in-situ abnormal monitoring system for wafers according to claim 1, characterized in that: The peripheral holes have multiple holes and are symmetrically arranged relative to the central hole. The multiple holes form multiple independent peripheral air ducts inside the stage, and the offset direction of the wafer when it deviates from the center is further judged by the pressure of the multiple holes.

4. A wafer in-situ anomaly monitoring system according to claim 2 or 3, characterized in that: A suction pipeline and a decompression pipeline are connected in parallel between the suction pump and the inlet of the stage. A vacuum adsorption valve and a desorption valve are respectively arranged on the suction pipeline and the decompression pipeline; a valve assembly is arranged on the main suction pipeline between the suction pump and the chamber. The desorption valve is connected to the main suction pipeline and is connected to the suction pump through the valve assembly; The diameter of the circle where the peripheral holes are arranged is 0.5 mm to 5 mm smaller than the diameter of the wafer. The high precision of the wafer back pad is 0.05 mm to 0.1 mm. The pressure gauge module two is arranged at the inlet of the pipeline when it enters the stage.

5. A method for in-situ abnormal monitoring of a wafer, characterized in that: Including: Adopt a wafer in-situ anomaly monitoring system according to claim 4; Control and monitor the changes in the chamber pressure and the back pressure of the wafer; Judge the matching and fitting degree between the evacuation hole area and the back surface of the wafer; Further judge whether there is an anomaly in the wafer in-situ; Distinguish whether the anomaly in the wafer in-situ is caused by the elevation of the back surface of the wafer or the deviation of the wafer slide from the center area of the stage.

6. A method for in-situ abnormal monitoring of a wafer according to claim 5, characterized in that: It includes at least one of the following modes: Adsorption mode: The back surface of the wafer is evacuated, and the wafer is adsorbed on the surface of the stage through the pressure difference between the front and back surfaces of the wafer. The adsorption mode includes: the desorption valve is closed, and the vacuum adsorption valve is opened; when the chamber pressure rises to the target pressure, check the back pressure of the wafer; check whether the back pressure of the wafer is less than threshold one. If it is less, the adsorption is successful; otherwise, the adsorption fails and the wafer in-situ is abnormal; or Detection mode: The back surface of the wafer is evacuated first, and then the vacuum adsorption valve and the desorption valve are closed to check the increase in the back pressure of the wafer. The detection mode includes: the desorption valve is closed, and the vacuum adsorption valve is opened; when the chamber pressure rises to the target pressure and stabilizes for a certain time, the vacuum adsorption valve is closed for a certain time and then opened; the chamber pressure rises to the target pressure; check whether the back pressure of the wafer is less than threshold three. If it is less, the wafer in-situ is normal; otherwise, the wafer in-situ is abnormal.

7. A method for in-situ abnormal monitoring of a wafer according to claim 6, characterized in that: It includes the following mode: Desorption mode: The back surface and the front surface of the wafer are connected to release the adsorption of the wafer. The desorption mode includes: the desorption valve is opened, and the vacuum adsorption valve is closed; check whether the difference between the chamber pressure and the back pressure of the wafer is less than threshold two. If it is less, the desorption is successful; otherwise, the desorption fails; and Idle mode: Both the vacuum adsorption valve and the desorption valve are closed.

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