Wafer measurement machine and cleaning method

Abstract

The present application discloses a wafer measuring machine, including a wafer stage, a vacuum pumping unit, a pressure blowing unit and a control unit. When the wafer stage is in the second position for measuring the wafer, the control unit is adjusted so that the vacuum pumping unit is connected to the adsorption hole to draw a vacuum into the adsorption hole, and the wafer is adsorbed on the wafer stage. After the wafer is measured, the control unit is adjusted so that the pressure blowing unit is connected to the adsorption hole, and pressurized gas is blown into the adsorption hole to remove the wafer. When the wafer stage is in the first position for cleaning, the control unit is adjusted so that the pressure blowing unit is connected to the adsorption hole, and pressurized gas is blown into the adsorption hole to clean the wafer stage, thereby improving the cleanliness of the wafer stage. The present application also discloses a method for cleaning a wafer measuring machine, wherein the control unit controls the pressure blowing unit to be connected to the adsorption hole to perform air pressure cleaning on the wafer stage, thereby improving the cleanliness of the wafer stage and improving the yield rate of the wafer.

Description

Technical Field

[0001] The present application relates to the field of semiconductor wafer processing, and in particular, to a wafer measuring machine and a wafer cleaning method. Background Art

[0002] During semiconductor wafer measurement, the wafer is typically placed on the wafer stage of the measurement machine for the corresponding operation. The wafer is placed on the wafer stage and vacuum suction is applied to the wafer via suction holes. After undergoing multiple processing steps, the wafer surface cleanliness may contain a certain amount of tiny particles, which can contaminate the wafer stage, reduce the stage's ability to hold the wafer, and affect product yield. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a wafer measuring machine and a cleaning method to improve the cleanliness of the wafer carrier of the measuring machine.

[0004] In one aspect of an embodiment of the present application, a wafer measurement machine is provided, comprising:

[0005] A movable wafer stage having a first position for cleaning and a second position for measuring the wafer, wherein adsorption holes are formed on the wafer stage;

[0006] a vacuum pumping unit connected to the adsorption hole, for vacuuming the adsorption hole to adsorb the wafer onto the wafer stage;

[0007] a pressure blowing unit connected to the adsorption hole, for blowing pressurized gas into the adsorption hole to perform air pressure cleaning on the adsorption hole or facilitate removal of the wafer; and

[0008] A control unit is used to control the vacuum pumping unit and the pressure blowing unit to be connected to or isolated from the adsorption hole respectively.

[0009] Furthermore, the control unit includes a three-way control valve having a first valve port, a second valve port and a third valve port;

[0010] The first valve port is communicated with the adsorption hole, the second valve port is communicated with the vacuum pumping unit, and the third valve port is communicated with the pressure blowing unit.

[0011] Furthermore, the control unit includes:

[0012] a first switch valve, connecting the vacuum pumping unit and the adsorption hole; and

[0013] The second switch valve connects the pressure blowing unit and the adsorption hole.

[0014] Furthermore, the control unit is configured for manual control or automatic control.

[0015] Furthermore, the pressure blowing unit is configured to blow a first pressure gas to perform air pressure cleaning on the adsorption hole, and the pressure blowing unit is configured to blow a second pressure gas to facilitate removal of the wafer, and the pressure of the first pressure gas is greater than the pressure of the second pressure gas.

[0016] Furthermore, the measuring machine also includes a collecting unit configured to suck particles on the wafer stage when the pressure blowing unit performs air pressure cleaning.

[0017] Furthermore, the collection unit includes:

[0018] a cover body configured to be able to cover the wafer stage to at least cover the adsorption hole; and

[0019] The lifting mechanism is configured to lift the cover body so as to move the cover body away from the wafer carrier or cover the adsorption hole.

[0020] Another aspect of the present application provides a method for cleaning a wafer measurement platform, comprising:

[0021] Moving the wafer stage to a first cleaning position;

[0022] Adjusting the control unit so that the pressure blowing unit is connected to the adsorption hole of the slide stage;

[0023] Controlling the pressure blowing unit to blow pressurized gas toward the adsorption hole to perform air pressure cleaning on the adsorption hole;

[0024] Adjusting the control unit to isolate the pressure blowing unit from the adsorption hole;

[0025] The wafer stage is moved so that the wafer stage is in a second position for measuring the wafer.

[0026] Furthermore, before the step of adjusting the control unit to connect the pressure blowing unit to the adsorption hole of the wafer stage, the cleaning method further includes:

[0027] The cover of the collecting unit is lowered to cover the wafer stage.

[0028] Furthermore, the cleaning method further comprises:

[0029] The collecting unit is controlled to draw a vacuum into the cover to suck the particles on the wafer stage.

[0030] An embodiment of the present application provides a wafer measurement platform. The platform includes a wafer carrier having suction holes that can be positioned in a first position for cleaning and a second position for wafer measurement. When the platform is in the second position for wafer measurement, a control unit is regulated to connect a vacuum pumping unit to the suction holes, evacuating the suction holes to absorb the wafer onto the platform for easy wafer measurement. After wafer measurement, the control unit is regulated to connect a pressure blowing unit to the suction holes, blowing pressurized gas into the holes to facilitate wafer removal. When the platform is in the first position for cleaning, the control unit is regulated to connect the pressure blowing unit to the suction holes, blowing pressurized gas into the holes to perform air pressure cleaning of the holes. The control unit is configured to control the vacuum pumping unit and the pressure blowing unit to connect or disconnect the suction holes, respectively. The pressure blowing unit is connected to the suction holes of the platform, and the control unit is regulated to blow pressurized gas into the holes to perform air pressure cleaning of the holes, thereby improving the cleanliness of the platform, reducing particle contamination of the wafers, and improving the wafer yield.

[0031] The embodiment of the present application provides a method for cleaning a wafer measuring machine. When cleaning the measuring machine, the wafer stage is moved so that the wafer stage is in a first cleaning position. The control unit is adjusted to connect the pressure blowing unit with the adsorption hole of the wafer stage. The pressure blowing unit is controlled to blow pressurized gas into the adsorption hole to perform air pressure cleaning on the adsorption hole. The control unit is adjusted to isolate the pressure blowing unit from the adsorption hole. After the cleaning of the measuring machine is completed, the wafer stage is moved so that the wafer stage is in a second position for measuring the wafer. With the wafer stage in the first cleaning position, the control unit controls the pressure blowing unit to blow pressurized gas into the adsorption hole to perform air pressure cleaning on the adsorption hole, thereby improving the cleanliness of the measuring machine and increasing the yield rate of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of a wafer measuring machine provided in an embodiment of the present application;

[0033] Figure 2 A schematic structural diagram of another wafer measurement machine provided in an embodiment of the present application;

[0034] Figure 3 The process of a wafer measuring machine cleaning method provided in the embodiment of the present application is Figure 1 ;as well as

[0035] Figure 4 The process of a wafer measuring machine cleaning method provided in the embodiment of the present application is Figure 2 .

[0036] Description of reference numerals:

[0037] 1-pressure blowing unit, 2-vacuum extraction unit, 3-slide stage, 3A-adsorption hole, 4-control unit, 41-three-way control valve, 41A-first valve port, 41B-second valve port, 41C-third valve port, 42-first switch valve, 43-second switch valve, 44-three-way connector, 5-collecting unit, 51-cover body, 52-lifting mechanism. DETAILED DESCRIPTION

[0038] The specific implementation methods of this application are described in detail below with reference to the accompanying drawings.

[0039] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of this application and should not be regarded as an improper restriction on this application.

[0040] In the description of this application, the terms "first, second, and third" are merely used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first, second, and third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0041] In the description of this application, the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings. It should be understood that these orientation terms are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting this application.

[0042] like Figure 1 As shown, an embodiment of the present application provides a wafer measuring machine, including a movable stage 3, a vacuum pumping unit 2, a pressure blowing unit 1 and a control unit 4. The movable stage 3 has a first position for cleaning and a second position for measuring the wafer, and an adsorption hole 3A is formed on the stage 3. The vacuum pumping unit 2 is connected to the adsorption hole 3A, and is used to draw a vacuum into the adsorption hole 3A to adsorb the wafer on the stage 3. The pressure blowing unit 1 is connected to the adsorption hole 3A, and is used to blow pressurized gas into the adsorption hole 3A to perform air pressure cleaning on the adsorption hole 3A or to facilitate the removal of the wafer. The control unit 4 is used to control the vacuum pumping unit 2 and the pressure blowing unit 1 to be connected to or isolated from the adsorption hole 3A respectively.

[0043] Specifically, when the wafer stage 3 is in the first cleaning position, the control unit 4 controls the pressure blowing unit 1 to be connected to the adsorption hole 3A, and the pressure blowing unit 1 blows in pressurized gas to perform air pressure cleaning on the wafer stage 3, thereby improving the cleanliness of the wafer stage 3 and increasing the yield rate of the wafer. When the wafer stage 3 is in the second position for measuring the wafer, the control unit 4 controls the vacuum exhaust unit 2 to be connected to the adsorption hole 3A, and vacuumizes the adsorption hole 3A, so that the wafer is quickly adsorbed on the adsorption hole 3A, which is convenient for wafer measurement. After the measurement, the control unit 4 controls the pressure blowing unit 1 to be connected to the adsorption hole 3A, and blows in pressurized gas so that the wafer on the adsorption hole 3A is easier to remove.

[0044] The aforementioned "air pressure cleaning" can be understood as removing particles clogged in the adsorption holes by blowing pressurized gas. Compared to cleaning with a cleaning liquid, which easily flows into the adsorption holes and becomes more difficult to remove after mixing with the liquid, the present application improves the cleanliness of the stage adsorption holes by using air pressure cleaning.

[0045] In one embodiment, the pressure blowing unit 1 is configured to blow a first pressure gas to perform air pressure cleaning on the adsorption hole 3A, and the pressure blowing unit 1 is configured to blow a second pressure gas to facilitate the removal of the wafer, and the pressure of the first pressure gas is greater than the pressure of the second pressure gas. Specifically, when cleaning the adsorption hole 3A, the pressure blowing unit 1 blows the first pressure gas, and uses the high-pressure gas to remove the particles in the adsorption hole 3A, unclog the adsorption hole 3A, and avoid clogging of the adsorption hole 3A, which causes the adsorption force to be reduced or the wafer to be contaminated. Particles are, for example, microparticles, debris or dust. When removing the wafer, the pressure blowing unit 1 blows the second pressure gas, and removes the wafer through the second pressure gas, eliminating the adsorption force of the adsorption hole 3A on the wafer, thereby conveniently removing the wafer and facilitating the next operation. By blowing different pressure gases through the pressure blowing unit 1, the wafer stage 3 can meet the needs of different operating conditions, so that the measuring machine has different usage scenarios.

[0046] In one embodiment, the control unit 4 includes a three-way control valve 41, such as a two-position, three-way slide valve. The three-way control valve 41 has a first valve port 41A, a second valve port 41B, and a third valve port 41C. The first valve port 41A is connected to the suction hole 3A, the second valve port 41B is connected to the vacuum pumping unit 2, and the third valve port 41C is connected to the pressure blowing unit 1. Specifically, the second valve port 41B is connected to the vacuum pumping unit 2, and the first valve port 41A is connected to the suction hole 3A. The three-way control valve 41 controls the communication between the first valve port 41A and the second valve port 41B, thereby connecting the vacuum pumping unit 2 to the suction hole 3A, thereby performing vacuuming. The third valve port 41C is connected to the pressure blowing unit 1, and the third valve port 41C is connected to the suction hole 3A. The three-way control valve 41 controls the communication between the first valve port 41A, the third valve port 41C, and the second valve port 41B, thereby connecting the pressure blowing unit 1 to the suction hole 3A, thereby performing pressure cleaning or wafer removal. Through the three-way control valve 41, the adsorption hole 3A can be connected to or isolated from the pressure blowing unit 1 and the vacuum exhaust unit 2 respectively, so as to quickly switch, improve the working efficiency, and improve the rapid switching between the cleaning and measurement states of the measuring machine.

[0047] In one embodiment, if Figure 2 As shown, the control unit 4 includes a first on-off valve 42 and a second on-off valve 43. The first on-off valve 42 connects the vacuum pumping unit 2 and the adsorption hole 3A, and the second on-off valve 43 connects the pressure blowing unit 1 and the adsorption hole 3A. Specifically, the control unit 4 includes a three-way connector 44, the first on-off valve 42, and the second on-off valve 43. One end of the three-way connector 44 is connected to the adsorption hole 3A, and the other two ends of the three-way connector 44 are respectively connected to the first on-off valve 42 and the second on-off valve 43. For example, a main on-off valve is connected between the three-way connector 44 and the adsorption hole 3A, and the main on-off valve controls the communication between the pressure blowing unit 1 and the vacuum pumping unit 2 and the adsorption hole 3A. By controlling the first switch valve 42 to connect the vacuum pumping unit 2 and the adsorption hole 3A, when the wafer stage 3 is in the second position for measuring the wafer, the adsorption hole 3A on the wafer stage 3 adsorbs the wafer. When the wafer stage 3 is in the first position for cleaning, the second switch valve 43 connects the pressure blowing unit 1 and the adsorption hole 3A, and the pressure blowing unit 1 blows pressurized gas to clean the wafer stage 3. The first switch valve 42 and the second switch valve 43 enable different operations to be performed when the wafer stage 3 is in different positions, thereby ensuring the cleanliness of the wafer stage 3 and improving the yield rate of the wafers.

[0048] In one embodiment, the control unit 4 is configured to be manually controlled or automatically controlled. Specifically, when the control unit 4 is automatically controlled, for example, the three-way control valve 41, the first switch valve 42, and the second switch valve 43 of the control unit 4 are all solenoid valves, which can automatically adjust the adsorption hole 3A to be connected to the vacuum pumping unit 2 or the pressure blowing unit 1 according to whether the wafer carrier 3 is in the first position for cleaning or the second position for measuring the wafer, thereby improving the degree of automation of the measuring machine and improving the operating efficiency. When the control unit 4 is manually controlled, for example, the three-way control valve 41, the first switch valve 42, and the second switch valve 43 of the control unit 4 are all manually operated valves, and the control unit 4 is controlled manually, so that the wafer carrier 3 can be flexibly controlled according to the needs of different operations. Through manual control or automatic control of the control unit 4, according to the different operations of cleaning or measuring the wafer on the wafer carrier 3, the control of the control unit 4 is more flexible and convenient, which meets the needs of actual operations.

[0049] In one embodiment, the measuring machine further includes a collection unit 5, which is configured to extract particles from the wafer stage 3 while the pressure blowing unit 1 is performing air pressure cleaning. Specifically, when the wafer stage 3 is in the first cleaning position, the pressure blowing unit 1 cleans the wafer stage 3, and the collection unit 5 extracts and collects the particles after the wafer stage 3 has been cleaned. This allows the particles cleaned from the wafer stage 3 to be removed from the measuring machine through the collection unit 5, preventing the particles from re-contaminating the machine or other wafer equipment. This improves the cleanliness of the measuring machine and ensures the yield rate of the wafers.

[0050] In one embodiment, the collection unit 5 includes a vacuum collection bag, a cover 51 and a lifting mechanism 52. The cover 51 is configured to be able to cover the wafer stage 3 to at least cover the adsorption holes 3A; the vacuum collection bag is connected to the cover 51 to collect particles on the wafer stage 3; the lifting mechanism 52 is configured to lift the cover 51 so that the cover 51 is away from the wafer stage 3 or covers the adsorption holes 3A. Specifically, when the wafer stage 3 is in the first cleaning position, the lifting mechanism 52 lowers the cover 51 so that the cover 51 covers the adsorption holes 3A, for example, covers the entire upper surface of the wafer stage 3, and the pressure blowing unit 1 cleans the adsorption holes 3A. After the particles cleaned by the wafer stage 3 are vacuum-sucked, they are transported to the vacuum collection bag through the cover 51. After the wafer stage 3 is cleaned, the lifting mechanism 52 lifts the cover 51 to leave space for the wafer stage 3 to measure the wafer, thereby facilitating the measurement operation. By raising and lowering the cover 51 through the lifting mechanism 52, the adsorption hole 3A is covered when the wafer stage 3 is cleaned, and space is left for measurement operations when measuring wafers, thereby making the measurement and cleaning of the wafer stage 3 more reasonable and facilitating related operations.

[0051] Another aspect of the embodiment of the present application is as follows Figure 3As shown, a method for cleaning a wafer measuring machine is provided, comprising:

[0052] S10, moving the slide stage to a first cleaning position;

[0053] S20, adjusting the control unit so that the pressure blowing unit is connected to the adsorption hole of the slide stage;

[0054] S30, controlling the pressure blowing unit to blow pressurized gas toward the adsorption holes to perform air pressure cleaning on the adsorption holes;

[0055] S40, adjusting the control unit to isolate the pressure blowing unit from the adsorption hole;

[0056] S50, moving the wafer stage to a second position for measuring the wafer.

[0057] The following combination Figure 3 , each step of the cleaning method for a wafer measuring machine according to an embodiment of the present application is specifically described. It should be noted that the order of the steps described below is merely for the convenience of describing a specific embodiment and does not constitute a limitation on the order of operations. In other embodiments, the order of the steps can be reasonably adjusted according to specific circumstances. S10, move the wafer stage to the first cleaning position.

[0058] Specifically, the wafer stage 3 has a first position for cleaning and a second position for measuring the wafer. The wafer stage 3 is in the second position when measuring the wafer. It should be understood that the wafer measurement system is located in a fixed position or posture. When the wafer stage 3 needs to be cleaned, the wafer stage 3 needs to be moved so that the wafer stage 3 is in the first position for cleaning, so that the wafer stage 3 can meet the different operations of cleaning and measuring the wafer.

[0059] S20, adjusting the control unit so that the pressure blowing unit is connected to the adsorption hole of the wafer stage.

[0060] Specifically, the three-way control valve 41 of the control unit 4 is adjusted so that the first valve port 41A is connected to the adsorption hole 3A, and the third valve port 41C is connected to the pressure blowing unit 1, thereby connecting the pressure blowing unit 1 to the adsorption hole 3A. By adjusting the control unit 4, the air path of the adsorption hole 3A of the slide stage 3 is connected.

[0061] Alternatively, the second switch valve 43 of the control unit 4 is adjusted to be in an open state, and the pressure blowing unit 1 is connected to the adsorption 3A, thereby connecting the air path of the adsorption hole 3A of the wafer stage 3.

[0062] S30, controlling the pressure blowing unit to blow pressurized gas toward the adsorption holes to perform air pressure cleaning on the adsorption holes.

[0063] Specifically, the pressure blowing unit 1 blows the first pressure gas to the adsorption hole 3A to perform air pressure cleaning on the adsorption hole 3A, thereby improving the cleanliness of the wafer stage 3, further improving the measurement result of the wafer, and improving the yield rate.

[0064] S40, adjusting the control unit to isolate the pressure blowing unit from the adsorption hole.

[0065] Specifically, after the cleaning of the wafer stage 3 is completed, the pressure blowing unit 1 is isolated from the adsorption hole 3A by adjusting the control unit 4, thereby completing the cleaning operation of the wafer stage 3 and facilitating the next measurement operation on the wafer on the wafer stage 3.

[0066] Alternatively, after the cleaning of the wafer stage 3 is completed, the first switch valve 43 of the control unit 4 is adjusted so that the first switch valve 43 is in a closed state, and the pressure blowing unit 1 is isolated from the adsorption hole 3A, thereby completing the cleaning operation of the wafer stage 3 and facilitating the next measurement operation on the wafer on the wafer stage 3.

[0067] S50, moving the wafer stage to a second position for measuring the wafer.

[0068] Specifically, the wafer stage 3 is in the first position when cleaning. After the wafer stage 3 is cleaned, the wafer stage 3 is moved when the wafer needs to be measured so that the wafer stage 3 is in the second position for measuring the wafer, which is convenient for measuring the wafer using the wafer measurement system.

[0069] In one embodiment, if Figure 4 As shown, before step S20 of adjusting the control unit 4 to connect the pressure blowing unit 1 with the adsorption hole 3A of the wafer stage 3, the cleaning method further includes:

[0070] S11 , lower the cover 51 of the collecting unit 5 to cover the wafer stage 3 .

[0071] Specifically, before the pressure blowing unit 1 is connected to the adsorption hole 3A, the cover body is lowered by adjusting the lifting mechanism 52, so that the cover body 51 covers the adsorption hole 3A, and further the particles during the cleaning of the adsorption hole 3A are collected by the cover body 51 and transferred to the vacuum collection bag, thereby preventing the particles during cleaning from contaminating the wafer or the measuring machine again.

[0072] In one embodiment, after step S11 of lowering the cover 51 of the collecting unit 5 to cover the wafer stage 3, the cleaning method further includes:

[0073] S12 , controlling the collecting unit 4 to draw a vacuum into the cover 51 to suck the particles on the wafer stage 3 .

[0074] Specifically, the cover body 51 covers the adsorption hole 3A. Before controlling the pressure blowing unit 1 to blow pressurized gas to the adsorption hole 3A to perform air pressure cleaning on the adsorption hole 3A, the collecting unit 4 is controlled to draw vacuum into the cover body 51 to suck the particles on the wafer stage 3. By drawing vacuum on the wafer stage 3 located in the cover body 51, the particles on the wafer stage 3 are cleaned.

[0075] Alternatively, after controlling the pressure blowing unit 1 to blow pressurized gas toward the adsorption holes 3A to perform air pressure cleaning on the adsorption holes 3A, the collection unit 4 is controlled to draw a vacuum into the cover 51 to aspirate particles on the wafer stage 3. For example, the pressure blowing unit 1 blows a first pressurized gas to clean the adsorption holes 3A of the wafer stage 3. The cleaned particles are collected in the cover 51, and the cover 51 is vacuumed to remove the cleaned particles and discharge them outside the measuring machine, thereby improving the cleanliness of the measuring machine.

[0076] In order to better understand the cleaning method of the embodiment of the present application, Figure 4 Further explanation will be given.

[0077] S10, move the wafer stage to the first cleaning position.

[0078] Specifically, the wafer stage 3 has a first position for cleaning and a second position for measuring the wafer. The wafer stage 3 is in the second position when measuring the wafer. It should be understood that the wafer measurement system is located in a fixed position or posture. When the wafer stage 3 needs to be cleaned, the wafer stage 3 needs to be moved so that the wafer stage 3 is in the first position for cleaning, so that the wafer stage 3 can meet the different operations of cleaning and measuring the wafer.

[0079] S11. Lower the cover of the collection unit to cover the wafer stage.

[0080] Specifically, the lifting mechanism 52 is adjusted to lower the cover body 51, so that the cover body 51 covers the adsorption hole 3A, and further the particles during the cleaning of the adsorption hole 3A are collected by the cover body 51 and transferred to the vacuum collection bag, thereby reducing the risk of particles during cleaning contaminating the wafer or the measuring machine again.

[0081] S12, controlling the collecting unit to draw vacuum into the cover to extract the particles on the wafer stage.

[0082] Specifically, the cover body 51 is provided with adsorption holes 3A, and the collection unit 4 is controlled to draw vacuum into the cover body 51 to suck the particles on the wafer stage 3. By drawing vacuum on the wafer stage 3 located in the cover body 51, the particles on the wafer stage 3 are cleaned.

[0083] S20, adjusting the control unit so that the pressure blowing unit is connected to the adsorption hole of the wafer stage.

[0084] Specifically, the three-way control valve 41 of the control unit 4 is adjusted so that the first valve port 41A is connected to the adsorption hole 3A, and the third valve port 41C is connected to the pressure blowing unit 1, thereby connecting the pressure blowing unit 1 to the adsorption hole 3A. By adjusting the control unit 4, the air path of the adsorption hole 3A of the slide stage 3 is connected.

[0085] Alternatively, the second switch valve 43 of the control unit 4 is adjusted to be in an open state, and the pressure blowing unit 1 is connected to the adsorption 3A, thereby connecting the air path of the adsorption hole 3A of the wafer stage 3.

[0086] S30, controlling the pressure blowing unit to blow gas toward the adsorption holes to perform air pressure cleaning on the adsorption holes.

[0087] Specifically, the pressure blowing unit 1 blows the first pressure gas to the adsorption hole 3A to perform air pressure cleaning on the adsorption hole 3A, thereby improving the cleanliness of the wafer stage 3, further improving the measurement result of the wafer, and improving the yield rate.

[0088] S40, adjusting the control unit to isolate the pressure blowing unit from the adsorption hole.

[0089] Specifically, after the cleaning of the wafer stage 3 is completed, the pressure blowing unit 1 is isolated from the adsorption hole 3A by adjusting the control unit 4, thereby completing the cleaning operation of the wafer stage 3 and facilitating the next measurement operation on the wafer on the wafer stage 3.

[0090] Alternatively, after the cleaning of the wafer stage 3 is completed, the first switch valve 43 of the control unit 4 is adjusted so that the first switch valve 43 is in a closed state, and the pressure blowing unit 1 is isolated from the adsorption hole 3A, thereby completing the cleaning operation of the wafer stage 3 and facilitating the next measurement operation on the wafer on the wafer stage 3.

[0091] S50, moving the wafer stage to a second position for measuring the wafer.

[0092] Specifically, the wafer stage 3 is in the first position when cleaning. After the wafer stage 3 is cleaned, the wafer stage 3 is moved when the wafer needs to be measured so that the wafer stage 3 is in the second position for measuring the wafer, which is convenient for measuring the wafer using the wafer measurement system.

[0093] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the above embodiments, or to replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present application.

Claims

1. A method for cleaning a wafer measuring machine, characterized in that: The wafer measurement machine includes: A movable wafer stage having a first position for cleaning and a second position for measuring the wafer, wherein adsorption holes are formed on the wafer stage; a vacuum pumping unit connected to the adsorption hole, for vacuuming the adsorption hole to adsorb the wafer onto the wafer stage; a pressure blowing unit connected to the adsorption hole, for blowing pressurized gas into the adsorption hole to perform air pressure cleaning on the adsorption hole or facilitate removal of the wafer; and a control unit, configured to control the vacuum pumping unit and the pressure blowing unit to be connected to or isolated from the adsorption holes respectively; a collecting unit configured to suck particles on the wafer stage when the pressure blowing unit performs air pressure cleaning; The cleaning method comprises: Moving the wafer stage to a first cleaning position; Before the step of adjusting the control unit to connect the pressure blowing unit to the adsorption hole of the wafer stage, lowering the cover of the collection unit to cover the wafer stage; Adjusting the control unit so that the pressure blowing unit is connected to the adsorption hole of the slide stage; Before controlling the pressure blowing unit to blow pressurized gas to the adsorption holes to perform air pressure cleaning on the adsorption holes, controlling the collecting unit to draw a vacuum into the cover to suck the particles on the wafer stage; Controlling the pressure blowing unit to blow pressurized gas toward the adsorption hole to perform air pressure cleaning on the adsorption hole; Adjusting the control unit to isolate the pressure blowing unit from the adsorption hole; The wafer stage is moved so that the wafer stage is in a second position for measuring the wafer.

2. The cleaning method according to claim 1, wherein The control unit includes a three-way control valve having a first valve port, a second valve port and a third valve port; The first valve port is communicated with the adsorption hole, the second valve port is communicated with the vacuum pumping unit, and the third valve port is communicated with the pressure blowing unit.

3. The cleaning method according to claim 1, wherein The control unit comprises: a first switch valve, connecting the vacuum pumping unit and the adsorption hole; and The second switch valve connects the pressure blowing unit and the adsorption hole.

4. The cleaning method according to claim 1, wherein The control unit is configured for manual control or automatic control.

5. The cleaning method according to claim 1, wherein The pressure blowing unit is configured to blow a first pressure gas to perform air pressure cleaning on the adsorption holes, and the pressure blowing unit is configured to blow a second pressure gas to facilitate removal of the wafer, and the pressure of the first pressure gas is greater than the pressure of the second pressure gas.

6. The cleaning method according to claim 1, wherein The collecting unit comprises: a cover body configured to be able to cover the wafer stage to at least cover the adsorption hole; and The lifting mechanism is configured to lift the cover body so as to move the cover body away from the wafer carrier or cover the adsorption hole.

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