Wafer detection equipment

Abstract

The utility model provides a wafer detection device, comprising a sample chamber used for placing a wafer to be detected; the electron gun chamber is communicated with the sample chamber; the electron gun is arranged in the electron gun chamber and is used for emitting electron beams to the wafer in the sample chamber; the pneumatic channel valve is arranged between the sample chamber and the electron gun chamber and is driven by a gas circuit to open and close so as to realize connection and disconnection between the sample chamber and the electron gun chamber; and the electromagnetic valve is arranged in the gas circuit and is configured to be driven by a circuit to be opened and closed so as to realize on-off of the gas circuit. The opening and closing control of the pneumatic channel valve is realized by controlling the on-off of the gas path through the electromagnetic valve, and when the vacuum degree in the sample chamber becomes lower, the gas in the sample chamber can be prevented from escaping into the electron gun chamber by closing the pneumatic channel valve in time, so that the adverse effect on the electron gun is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor, in particular to a wafer detection equipment. BACKGROUND

[0002] Charged particle beam detection equipment has a wide application in semiconductor industry, for example, including scanning electron microscope, environmental scanning electron microscope, electron beam defect detection equipment, electron beam critical dimension measurement equipment, focused ion beam microscope, double beam microscope and the like. Among them, the part of generating charged particle beam is generally called electron gun or ion gun. In order to ensure the stable operation and service life of the electron gun, the working environment of the electron gun needs to maintain a high vacuum degree. For the area of the detection equipment for placing the sample (wafer) to be detected, due to the need of sample replacement or actual detection speed, the vacuum degree of the area is easy to become lower, which is easy to cause adverse effects on the electron gun. SUMMARY

[0003] One object of the utility model is to provide a wafer detection equipment capable of separating the electron gun and the sample chamber to reduce the influence of the vacuum degree change of the sample chamber on the electron gun.

[0004] A further object of the utility model is to timely close the pneumatic passage valve in the case of solenoid valve failure.

[0005] In particular, the utility model provides a wafer detection equipment, comprising:

[0006] A sample chamber for placing a wafer to be detected;

[0007] An electron gun chamber communicatively arranged with the sample chamber;

[0008] An electron gun arranged in the electron gun chamber and configured to emit an electron beam to the wafer in the sample chamber;

[0009] A pneumatic passage valve arranged between the sample chamber and the electron gun chamber and driven to open and close by a gas circuit to realize the connection and disconnection between the sample chamber and the electron gun chamber; and

[0010] A solenoid valve arranged in the gas circuit and configured to be driven to open and close by an electric circuit to realize the connection and disconnection of the gas circuit.

[0011] Optionally, the wafer detection equipment further comprises:

[0012] A mechanical valve also arranged in the gas circuit and connected in series with the solenoid valve, so that the gas circuit is cut off in the state that any one of the mechanical valve and the solenoid valve is closed; and

[0013] The pneumatic passage valve is configured to be opened in the state that the gas circuit is connected.

[0014] Optionally, the wafer detection device further comprises:

[0015] a pressure sensor disposed in the sample chamber for detecting a pressure in the sample chamber; and

[0016] a circuit switch disposed in the circuit, the circuit switch being configured to open or close according to a detection value of the pressure sensor to realize on-off of the circuit.

[0017] Optionally, the electromagnetic valve is configured to open in a state where the circuit is turned on.

[0018] Optionally, the wafer detection device further comprises:

[0019] a first vacuum pump in communication with the sample chamber for evacuating air in the sample chamber.

[0020] Optionally, the pressure sensor and the first vacuum pump are respectively disposed on opposite sides of the sample chamber.

[0021] Optionally, the wafer detection device further comprises:

[0022] a second vacuum pump in communication with the electron gun chamber for evacuating air in the electron gun chamber.

[0023] Optionally, the electromagnetic valve is configured to close under a condition that the detection value of the pressure sensor is greater than or equal to a first preset threshold value.

[0024] Optionally, the electromagnetic valve is configured to close in a process that the detection value of the pressure sensor decreases from the first preset threshold value to a second preset threshold value, the second preset threshold value being less than the first preset threshold value.

[0025] Optionally, the first preset threshold value is greater than or equal to 1×10 -5 Torr and less than or equal to 1×10 -4 Torr, and the second preset threshold value is greater than or equal to 1×10 -6 Torr and less than or equal to 8×10 -6 Torr.

[0026] The wafer detection equipment of the utility model discloses a pneumatic channel valve is arranged between sample chamber and electron gun chamber, and the pneumatic channel valve is driven to open and close by gas circuit to realize the on-off between sample chamber and electron gun chamber, when the pneumatic channel valve opens, the electron gun in electron gun chamber can normally emit electron beam to the wafer in sample chamber, thereby detecting the wafer, when the pneumatic channel valve closes, electron gun chamber and sample chamber are cut off, so that electron gun chamber and sample chamber realize airtight isolation, thereby the gas in sample chamber cannot escape into electron gun chamber, in this way, when the vacuum degree in sample chamber becomes lower, the gas in sample chamber can be prevented from escaping into electron gun chamber by closing the pneumatic channel valve, thereby avoiding the adverse effect on the electron gun, in addition, the opening and closing control of the pneumatic channel valve is realized by controlling the on-off of the gas circuit by the electromagnetic valve, because the electromagnetic valve is driven to open and close by the circuit, automatic control can be realized, so the closing of the pneumatic channel valve can be realized more quickly and timely by controlling the on-off of the gas circuit by the electromagnetic valve, furthermore, the electromagnetic valve and the pneumatic channel valve cooperate, realize the quick blocking of electron gun chamber and sample chamber, and make the electromagnetic valve away from the electron gun, avoiding the influence of the magnetic field on the electron gun.

[0027] Further, the wafer detection equipment of the utility model realizes the cut-off of the gas circuit and the closing of the pneumatic channel valve by connecting the mechanical valve and the electromagnetic valve in the gas circuit, that is, the mechanical valve controlled manually is provided in addition to the electromagnetic valve controlled automatically to close the pneumatic channel valve, thereby helping the management personnel to choose the timing of closing the pneumatic channel valve flexibly, in addition, the mechanical valve can be used to close the pneumatic channel valve in time in the case of electromagnetic valve failure, effectively avoiding the situation that the pneumatic channel valve cannot be closed due to electromagnetic valve failure, thereby causing the adverse effect on the electron gun.

[0028] The above and other objects, advantages and features of the present utility model will become more apparent from the following detailed description of some embodiments thereof, when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] Some embodiments of the present utility model will be described in detail hereinafter with reference to the drawings, which are presented by way of illustration and not of limitation. The same reference numbers in different drawings represent the same or similar components or parts. It should be understood by those skilled in the art that the drawings are not necessarily drawn to scale. In the drawings:

[0030] Figure 1 is a schematic diagram of the wafer detection equipment according to an embodiment of the utility model;

[0031] Figure 2 is a schematic circuit diagram of the working principle of the pneumatic channel valve of the wafer detection equipment according to an embodiment of the utility model;

[0032] Figure 3 is a schematic block diagram of working principle of a pneumatic channel valve of a wafer detection device according to an embodiment of the present application;

[0033] Figure 4 is a schematic curve diagram of corresponding relationship between electromagnetic valve switch state and pressure in sample chamber in a wafer detection device according to an embodiment of the present application.

[0034] Marked explanation:

[0035] 10, wafer detection device; 100, sample chamber; 200, electron gun chamber; 300, electron gun; 400, pneumatic channel valve; 410, gas circuit; 500, electromagnetic valve; 510, circuit; 520, circuit switch; 600, mechanical valve; 700, pressure sensor; 800, first vacuum pump; 900, second vacuum pump. DETAILED DESCRIPTION

[0036] Those skilled in the art should understand that the embodiments described below are only a part of the embodiments of the present application, not all the embodiments of the present application, and the part of the embodiments are intended to explain the technical principles of the present application, not to limit the protection scope of the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the protection scope of the present application.

[0037] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0038] Further, it should be further pointed out that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0039] AsFigures 1 to 2 As shown in FIG. 1, in one embodiment, the wafer detection device 10 includes a sample chamber 100, an electron gun chamber 200, an electron gun 300, a pneumatic passage valve 400, and a solenoid valve 500. The sample chamber 100 is configured to hold a wafer to be detected. The electron gun chamber 200 is disposed in communication with the sample chamber 100. The electron gun 300 is disposed in the electron gun chamber 200 and configured to emit an electron beam toward the wafer in the sample chamber 100. The pneumatic passage valve 400 is disposed between the sample chamber 100 and the electron gun chamber 200 and is driven to open and close by a gas path 410 to achieve the communication and isolation between the sample chamber 100 and the electron gun chamber 200. The solenoid valve 500 is disposed in the gas path 410 and is configured to be driven to open and close by an electric circuit 510 to achieve the communication and isolation of the gas path 410.

[0040] Referring to Figure 1 and Figure 2 As shown in FIG. 1, specifically, the sample chamber 100 and the electron gun chamber 200 are arranged in a longitudinal direction, and the electron gun 300 is disposed at the top of the electron gun chamber 200. In use, the wafer to be detected is placed in the sample chamber 100 and aligned with the electron gun 300 in the longitudinal direction. The electron gun 300 is capable of emitting an electron beam in the longitudinal direction so that the electron beam is directed to the wafer in the sample chamber 100, thereby achieving the detection of the wafer.

[0041] As shown in FIG. 1, Figure 1 and Figure 2 The pneumatic passage valve 400 is disposed between the sample chamber 100 and the electron gun chamber 200, or in other words, the pneumatic passage valve 400 separates the sample chamber 100 and the electron gun chamber 200. When the pneumatic passage valve 400 is in an open state, the electron gun chamber 200 and the sample chamber 100 are in communication, and the electron beam emitted by the electron gun 300 can reach the wafer in the sample chamber 100. When the pneumatic passage valve 400 is in a closed state, the electron gun chamber 200 and the sample chamber 100 are isolated, that is, the electron gun chamber 200 and the sample chamber 100 are hermetically isolated, so that the gas in the sample chamber 100 cannot escape into the electron gun chamber 200.

[0042] Referring to Figure 1 and Figure 2 As shown in FIG. 1, the pneumatic passage valve 400 is driven to open and close by the gas path 410 and is configured to be open in a state where the gas path 410 is in a conduction state. That is, in the conduction state of the gas path 410, the gas flows along the gas path 410 to the pneumatic passage valve 400, and the pneumatic passage valve 400 opens under the action of the gas pressure; and in the isolation state of the gas path 410, the pneumatic passage valve 400 loses the action of the gas pressure and returns to the closed state under the action of a return structure such as a spring.

[0043] Continuing to refer to Figure 1 and Figure 2As shown, the electromagnetic valve 500 is arranged in the gas path 410, when the electromagnetic valve 500 is opened, the gas path 410 is connected, the pneumatic passage valve 400 is opened, when the electromagnetic valve 500 is closed, the gas path 410 is disconnected, and the pneumatic passage valve 400 is closed. In other words, by controlling the opening and closing of the electromagnetic valve 500, the connection and disconnection of the gas path 410 can be controlled, and in turn the opening and closing of the pneumatic passage valve 400 can be controlled, so that the connection and disconnection between the electron gun chamber 200 and the sample chamber 100 can be controlled.

[0044] In the scheme of the present embodiment, by arranging the pneumatic passage valve 400 between the sample chamber 100 and the electron gun chamber 200, the pneumatic passage valve 400 is driven to open and close by the gas path 410 to realize the connection and disconnection between the sample chamber 100 and the electron gun chamber 200. When the pneumatic passage valve 400 is opened, the electron gun 300 in the electron gun chamber 200 can normally emit an electron beam to the wafer in the sample chamber 100, so as to detect the wafer. When the pneumatic passage valve 400 is closed, the electron gun chamber 200 and the sample chamber 100 are disconnected, so that the electron gun chamber 200 and the sample chamber 100 are hermetically isolated, so that the gas in the sample chamber 100 cannot escape into the electron gun chamber 200. In this way, when the vacuum degree in the sample chamber 100 becomes lower, the gas in the sample chamber 100 can be prevented from escaping into the electron gun chamber 200 by closing the pneumatic passage valve 400, thereby avoiding adverse effects on the electron gun 300.

[0045] In addition, the opening and closing of the pneumatic passage valve 400 is realized by controlling the connection and disconnection of the gas path 410 by the electromagnetic valve 500. Because the electromagnetic valve 500 is driven to open and close by the circuit 510, automatic control can be realized, so that the closing of the pneumatic passage valve 400 can be realized more quickly and timely by controlling the connection and disconnection of the gas path 410 by the electromagnetic valve 500. Moreover, the electromagnetic valve 500 and the pneumatic passage valve 400 cooperate to realize the rapid isolation of the electron gun chamber 200 and the sample chamber 100, and the electromagnetic valve 500 is away from the electron gun 300, so as to avoid the influence of the magnetic field on the electron gun 300.

[0046] It should be noted that in other embodiments, the pneumatic passage valve 400 can also be closed in the state of the gas path being connected, and opened in the state of the gas path being disconnected.

[0047] In addition, it should be noted that in other embodiments, the relative positions of the electron gun chamber and the sample chamber can also be other arrangements, such as transverse arrangement, etc.

[0048] As Figures 1 to 3As shown, the wafer inspection equipment 10 also includes a mechanical valve 600, which is also disposed in the gas path 410 and connected in series with the solenoid valve 500, so that the gas path 410 is isolated when either the mechanical valve 600 or the solenoid valve 500 is closed. In other words, closing either the solenoid valve 500 or the mechanical valve 600 can isolate the gas path 410. Furthermore, because the pneumatic channel valve 400 is open when the gas path 410 is open and closed when the gas path 410 is isolated, closing either the solenoid valve 500 or the mechanical valve 600 can close the pneumatic channel valve 400, thus isolating the sample chamber 100 and the electron gun chamber 200.

[0049] Those skilled in the art will understand that by connecting the mechanical valve 600 and the solenoid valve 500 in series in the pneumatic circuit 410, the pneumatic circuit 410 can be isolated by closing either the solenoid valve 500 or the mechanical valve 600, thereby closing the pneumatic passage valve 400. In other words, in addition to the automatically controlled solenoid valve 500, a manually controlled mechanical valve 600 is provided to close the pneumatic passage valve 400, thus helping managers to flexibly choose when to close the pneumatic passage valve 400. Furthermore, in the event of a malfunction of the solenoid valve 500, the mechanical valve 600 can be used to promptly close the pneumatic passage valve 400, effectively preventing a situation where a malfunction of the solenoid valve 500 prevents the pneumatic passage valve 400 from closing, which could adversely affect the electron gun 300.

[0050] like Figures 1 to 3 As shown, in one embodiment, the wafer inspection apparatus 10 includes a pressure sensor 700 and a circuit switch 520. The pressure sensor 700 is disposed within the sample chamber 100 and is used to detect the pressure within the sample chamber 100. The circuit switch 520 is disposed in the circuit 510 and is configured to open and close according to the detection value of the pressure sensor 700 to realize the on / off state of the circuit 510.

[0051] Reference Figures 1 to 3 As shown, the pressure sensor 700 can be a pressure sensor known to those skilled in the art, such as a vacuum gauge. The circuit switch 520 is a relay, which opens and closes based on the detection signal from the pressure sensor 700, thereby controlling the on / off state of circuit 510, which in turn controls the opening and closing of the solenoid valve 500. The solenoid valve 500 controls the on / off state of the air passage 410, thus controlling the opening and closing of the pneumatic channel valve 400. In summary, the pneumatic channel valve 400 opens and closes based on the detection signal from the pressure sensor 700, and the pressure within the sample chamber 100 reflects the vacuum level within the sample chamber 100. In other words, the pneumatic channel valve 400 opens and closes based on the vacuum level within the sample chamber 100.

[0052] In the scheme of the embodiment, by setting the pressure sensor 700 in the sample chamber 100, the opening and closing of the circuit switch 520 in the circuit 510 is controlled by the pressure sensor 700, and then the opening and closing of the electromagnetic valve 500 is realized, and the electromagnetic valve 500 can realize the opening and closing of the gas circuit 410, thereby realizing the opening and closing of the pneumatic channel valve 400. That is, the pneumatic channel valve 400 can be opened and closed according to the detection signal of the pressure sensor 700, and the pressure in the sample chamber 100 reflects the vacuum degree in the sample chamber 100, in other words, the pneumatic channel valve 400 can be opened and closed according to the vacuum degree in the sample chamber 100, so that the pneumatic channel valve 400 can be closed in time when the vacuum degree in the sample chamber 100 is low.

[0053] Referring to Figures 1 to 3 As shown in FIG. 6, the electromagnetic valve 500 is configured to be opened in the state that the circuit 510 is turned on, that is, in the state that the circuit 510 is turned on, the electromagnetic valve 500 is opened, the gas circuit 410 is turned on, and the pneumatic channel valve 400 is opened; in the state that the circuit 510 is turned off, the electromagnetic valve 500 is closed, the gas circuit 410 is cut off, and the pneumatic channel valve 400 is closed. By the above configuration, the electromagnetic valve 500 is in the closed state when the circuit 510 fails, which helps to avoid the situation that the electromagnetic valve 500 cannot be closed in time due to the failure of the circuit 510 compared with the way that the electromagnetic valve 500 is closed in the state that the circuit 510 is turned on.

[0054] It should be noted that in some other embodiments, the electromagnetic valve can also be configured to be closed in the state that the circuit is turned on and opened in the state that the circuit is turned off.

[0055] Referring to Figures 1 to 4 As shown in FIG. 6, the electromagnetic valve 500 is configured to be closed under the condition that the detection value of the pressure sensor 700 is greater than or equal to a first preset threshold, and the first preset threshold is greater than or equal to 1x10 -5 Torr (Torr, unit of pressure), less than or equal to 1x10 -4 Torr. For example, it can be 1x10 -5 Torr, 3x10 -5 Torr, 5x10 -5 Torr, 7x10 -5 Torr or 1x10 - 4 Torr, etc.

[0056] Specifically, when the detection value of the pressure sensor 700 is greater than or equal to the first preset threshold, that is, the pressure in the sample chamber 100 is high, that is, the vacuum degree is low, the circuit switch 520 is turned off, the electromagnetic valve 500 is closed, the gas circuit 410 is cut off, and the pneumatic channel valve 400 is closed.

[0057] Referring to Figures 1 to 4 In addition, the electromagnetic valve 500 is configured to be closed during the process that the detection value of the pressure sensor 700 decreases from the first preset threshold to the second preset threshold, and the second preset threshold is less than the first preset threshold. The second preset threshold is greater than or equal to 1x10 -6 Torr and less than or equal to 8x10 -6 Torr. For example, it can be 1x10 -6 Torr, 2x10 -6 Torr, 3x10 -6 Torr, 4x10 -6 Torr, 5x10 -6 Torr, 6x10 -6 Torr, 7x10 -6 Torr or 8x10 -6 Torr, etc. And the electromagnetic valve 500 is configured to be opened during the process that the detection value of the pressure sensor 700 increases from the second preset threshold to the first preset threshold, under the condition that the detection value of the pressure sensor 700 is less than or equal to the second preset threshold.

[0058] As Figure 4 shown, that is, when the pressure in the sample chamber 100 starts to decrease from the atmospheric pressure, the electromagnetic valve 500 is not immediately opened, that is, the pneumatic channel valve 400 is not immediately opened, until the pressure in the sample chamber 100 continues to decrease to the second preset threshold, then the electromagnetic valve 500 is opened, that is, the pneumatic channel valve 400 is opened, so that a safety observation time is set for the timing of opening the pneumatic channel valve 400 during the process that the pressure in the sample chamber 100 starts to decrease from the atmospheric pressure, and the pneumatic channel valve 400 is opened after ensuring that the pressure in the sample chamber 100 can be stably decreased, which helps to ensure the safety of the working environment of the electron gun 300.

[0059] It should be noted that the circuit switch is realized by the connection of pure hardware circuits such as pressure sensors and comparators. For example, a hysteresis comparator can be arranged between the pressure sensor and the circuit switch. The hysteresis comparator has a high threshold value and a low threshold value. The signal of the pressure sensor needs to cross different threshold values in the process of rising or falling, and the hysteresis comparator will change the output state. In combination with the embodiment, that is, the first preset threshold value and the second preset threshold value correspond to the high threshold value and the low threshold value of the hysteresis comparator respectively. When the circuit switch is disconnected, only the signal of the pressure sensor less than or equal to the second preset threshold value will cause the hysteresis comparator to change the output state, that is, the circuit switch changes the state, that is, it is closed. After the circuit switch is closed, only the signal of the pressure sensor greater than or equal to the first preset threshold value will cause the hysteresis comparator to change the output state, that is, the circuit switch changes the state, that is, it is disconnected. Thus, the electromagnetic valve is closed in the process that the detection value of the pressure sensor decreases from the first preset threshold value to the second preset threshold value, and is opened in the process that the detection value of the pressure sensor increases from the second preset threshold value to the first preset threshold value.

[0060] As shown in Figure 1 In one embodiment, the wafer detection device 10 further includes a first vacuum pump 800 in communication with the sample chamber 100 for evacuating air in the sample chamber 100. The first vacuum pump 800 can be a separate molecular pump, or a component composed of a mechanical pump and a molecular pump. The first vacuum pump 800 forms a high-vacuum environment in the sample chamber 100 by evacuating air in the sample chamber 100, thereby providing a good working environment for the electron gun 300.

[0061] As shown in Figure 1 The pressure sensor 700 and the first vacuum pump 800 are arranged on opposite sides of the sample chamber 100. Specifically, the pressure sensor 700 is arranged opposite to the connection position of the first vacuum pump 800 and the sample chamber 100. In this way, the distance between the pressure sensor 700 and the first vacuum pump 800 is relatively far. During the process of evacuating the sample chamber 100 by the first vacuum pump 800, after the detection value of the pressure sensor 700 meets the working requirements of the electron gun 300, it can be ensured that the environment of most or all of the sample chamber 100 area meets the requirements, which is beneficial to ensure that the electron gun 300 obtains a good working environment.

[0062] As shown in Figure 1As shown, in one embodiment, the wafer detection device 10 further comprises a second vacuum pump 900, which is in communication with the electron gun chamber 200, for pumping away the air in the electron gun chamber 200. Specifically, the second vacuum pump 900 can be a separate molecular pump, or a combination of a molecular pump and a mechanical pump. The second vacuum pump 900 forms a higher vacuum environment in the electron gun chamber 200 by pumping away the air in the electron gun chamber 200, so that the sample chamber 100 and the electron gun chamber 200 can be independently pumped, thereby providing a better working environment for the electron gun 300.

[0063] It should be noted that the specific structures of the pneumatic channel valve, the electromagnetic valve and the mechanical valve in the above embodiments are known to those skilled in the art, and will not be described in detail.

[0064] At this point, those skilled in the art should realize that although the present application has been shown and described in detail in the above embodiments, many other variants or modifications conforming to the principles of the present application can be directly determined or deduced from the content disclosed in the present application without departing from the spirit and scope of the present application. Therefore, the scope of the present application should be understood and recognized as covering all these other variants or modifications.

Claims

1. A wafer inspection device, characterized in that, include: The sample chamber is used to hold the wafer to be tested; The electron gun chamber is connected to the sample chamber. An electron gun, disposed within the electron gun chamber, is used to emit an electron beam into the wafer within the sample chamber; A pneumatic channel valve is disposed between the sample chamber and the electron gun chamber, and is driven to open and close by a pneumatic path to realize the connection and disconnection between the sample chamber and the electron gun chamber; and A solenoid valve is installed in the air passage and configured to be opened and closed by a circuit to realize the opening and closing of the air passage.

2. The wafer inspection equipment according to claim 1, characterized in that... Also includes: A mechanical valve is also provided in the air passage and connected in series with the solenoid valve, such that the air passage is isolated when either the mechanical valve or the solenoid valve is closed; and... The pneumatic channel valve is configured to open when the air path is open and close when the air path is closed.

3. The wafer inspection equipment according to claim 2, characterized in that... Also includes: A pressure sensor is disposed in the sample chamber to detect the pressure in the sample chamber; and A circuit switch is disposed in the circuit and is configured to open and close according to the detection value of the pressure sensor to realize the on / off state of the circuit.

4. The wafer inspection equipment according to claim 3, characterized in that, The solenoid valve is configured to open when the circuit is on.

5. The wafer inspection equipment according to claim 3, characterized in that... Also includes: A first vacuum pump, connected to the sample chamber, is used to remove air from the sample chamber.

6. The wafer inspection equipment according to claim 5, characterized in that, The pressure sensor and the first vacuum pump are respectively located on opposite sides of the sample chamber.

7. The wafer inspection equipment according to claim 5, characterized in that... Also includes: A second vacuum pump, connected to the electron gun chamber, is used to evacuate the air from the electron gun chamber.

8. The wafer inspection equipment according to claim 3, characterized in that, The solenoid valve is configured to close when the pressure sensor detects a value greater than or equal to a first preset threshold.

9. The wafer inspection equipment according to claim 8, characterized in that, The solenoid valve is configured to close as the detected value of the pressure sensor decreases from the first preset threshold to the second preset threshold, where the second preset threshold is less than the first preset threshold.

10. The wafer inspection equipment according to claim 9, characterized in that, The first preset threshold is greater than or equal to 1×10 -5 Torr is less than or equal to 1×10 -4 Torr, the second preset threshold is greater than or equal to 1×10 -6 Torr is less than or equal to 8 × 10 -6 Torr.

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