Wafer conveying box

Abstract

The utility model provides a wafer transfer box which mainly comprises a box body, the box body is provided with a pump valve and an air valve, the pump valve is used for pumping air from the box body to adjust the pressure in the box body, and the air valve is used for filling protective gas into the box body; the air pressure control mechanism is respectively connected with the pump valve and the air valve, and the air pressure control mechanism is used for respectively controlling the opening or closing of the pump valve and the air valve. By controlling the air pressure change of the box body, the adhesion viscosity of an organic compound which exists in the deep layer of the wafer surface image or volatilizes slowly is reduced, the impurity removal degree in the wafer conveying box is improved, wafer defects caused by impurities in the wafer production environment are reduced, and the wafer yield is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a wafer transfer box. Background Art

[0002] A wafer cassette is a container used to protect, transport and store wafers. When switching between different processes, a wafer cassette can be used to carry and transport wafers. As wafers are placed in the cassette, the internal environment of the cassette gradually converges with the wafer production environment due to the effect of gas diffusion, resulting in impurities such as moisture, dust particles, metal ions and volatile organic compounds in the production environment also existing in the internal environment of the cassette, which may damage the surface structure or electronic properties of the wafer, thereby reducing the wafer yield.

[0003] In the related art, nitrogen can be used to purge the inside of the wafer transfer box to clean the wafers and exhaust to remove impurities inside the wafer transfer box. However, organic compounds that exist deep in the wafer surface image or evaporate slowly are difficult to completely remove by nitrogen purge, and the internal environment of the wafer transfer box may still cause damage to the surface structure or electronic characteristics of the wafer, thereby reducing the wafer yield. Utility Model Content

[0004] The technical problem to be solved by the present application is that the existing method of purging the inside of a wafer transfer box with nitrogen is difficult to completely remove impurities inside the wafer transfer box, resulting in a low wafer yield.

[0005] In order to solve the above-mentioned technical problems, the present application provides a wafer transfer box, comprising: a box body, the box body is provided with a pump valve and an air valve, the pump valve is used to extract air from the box body to adjust the pressure in the box body, and the air valve is used to fill the box body with protective gas; an air pressure control mechanism, the air pressure control mechanism is respectively connected to the pump valve and the air valve, and the air pressure control mechanism is used to respectively control the opening or closing of the pump valve and the air valve.

[0006] In some embodiments of the present application, the air pressure control mechanism includes: a loading platform, which is arranged on one side of the box body; an exhaust pipe, which is located on the loading platform and is detachably connected to the pump valve; an inflation pipe, which is located on the loading platform and is detachably connected to the air valve; and a controller, wherein a first control end in the controller is electrically connected to the pump valve, and a second control end in the controller is electrically connected to the air valve.

[0007] In some embodiments of the present application, the inflation tube is connected to a gas source of the protective gas.

[0008] In some embodiments of the present application, the protective gas is nitrogen or argon.

[0009] In some embodiments of the present application, a first positioning component is provided on one side of the box body; a second positioning component is provided on the stage, and the first positioning component is adapted to the second positioning component.

[0010] In some embodiments of the present application, when the first positioning component is a positioning groove, the second positioning component is a positioning protrusion adapted to the positioning groove.

[0011] In some embodiments of the present application, when the first positioning component is a positioning protrusion, the second positioning component is a positioning groove adapted to the positioning protrusion.

[0012] In some embodiments of the present application, the air pressure control mechanism also includes: a first pressure sensor arranged in the exhaust pipe, and a second pressure sensor arranged in the inflation pipe; the first pressure sensor and the second pressure sensor are both used to detect the internal pressure of the box body.

[0013] In some embodiments of the present application, the pump valve is a one-way valve, or the pump valve is a one-way valve with adjustable flux.

[0014] In some embodiments of the present application, the gas valve is a one-way valve, or the gas valve is a one-way valve with adjustable flux.

[0015] Compared with the prior art, the technical solution of the present application reduces the adhesion and viscosity of organic compounds that exist deep in the wafer surface image or evaporate slowly by controlling the air pressure change of the box body, thereby improving the degree of impurity removal inside the wafer transfer box, reducing wafer defects caused by impurities in the wafer production environment, and improving the wafer yield. Moreover, it can also reduce the impurity removal time, improve the impurity removal efficiency inside the wafer transfer box, reduce the wafer production cycle, and thus improve the wafer production efficiency. In addition, reducing the impurity removal time can reduce the amount of protective gas used, thereby reducing the cost of protective gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

[0017] Figure 1 is a schematic diagram of the structure of a wafer transfer box according to some embodiments of the present application;

[0018] Description of the accompanying drawings: 11-box body, 111-pump valve, 112-air valve, 12-air pressure control mechanism, 121-stage, 122-exhaust pipe, 123-inflating pipe, 124-controller. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation. It should be clearly understood that the drawings are only for the purpose of illustration and description and are not intended to limit the scope of disclosure of this specification.

[0020] It should be understood that the "module" and "circuit" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0021] The terms used in this application are only for the purpose of describing specific example embodiments and are not restrictive. When used in this specification, the terms "include", "comprises" and / or "contains" mean the existence of the associated integers, steps, operations, elements and / or components, but do not exclude the existence of one or more other features, integers, steps, operations, elements, components and / or groups or the addition of other features, integers, steps, operations, elements, components and / or groups in the wafer transfer box. When describing the association of different components in this specification, it can be a direct relationship or an indirect relationship. For example, "A and B are connected" can mean that A and B are directly connected, or A and B are indirectly connected through other components.

[0022] Wafer pods are widely used wafer transfer carriers in the semiconductor manufacturing process. Wafer pods can separate wafers from the semiconductor production environment to prevent particles, metal ions, volatile organic compounds and other substances from affecting the wafers. For example, a front-opening wafer pod includes a front-opening container and a door frame. The front-opening container can accommodate 25 300mm wafers, and the front-opening container is opened or closed by the door frame.

[0023] After the wafer is placed in the wafer transfer box, nitrogen can be used to purge the inside of the wafer transfer box to clean the wafer and remove impurities inside the wafer transfer box. However, organic compounds that exist deep in the wafer surface image or evaporate slowly are difficult to completely remove by nitrogen purge, and the internal environment of the wafer transfer box may still cause damage to the surface structure or electronic characteristics of the wafer, thereby reducing the wafer yield.

[0024] Specifically, after wafer processing (such as wet etching, dry etching and photolithography), the internal environment of the wafer transfer box can be improved by purging the inside of the wafer transfer box with nitrogen to remove acidic gases or water vapor, reduce wafer collision defects and wafer pattern damage caused by exhaust gas and condensation. However, it is difficult to completely remove organic compounds that exist deep in the wafer surface image or evaporate slowly. If the nitrogen purge time is increased or the nitrogen gas source is increased, although the wafer yield can be improved, it will require more wafer processing time or wafer processing costs.

[0025] Based on the above analysis, if Figure 1 As shown, the wafer transfer box provided in the embodiment of the present application may include:

[0026] A box body 11, wherein the box body 11 is provided with a pump valve 111 and an air valve 112, wherein the pump valve 111 is used to extract gas from the box body 11 to adjust the pressure in the box body 11, and the air valve 112 is used to fill the box body 11 with protective gas;

[0027] The air pressure control mechanism 12 is connected to the pump valve 111 and the air valve 112 respectively, and is used to control the opening or closing of the pump valve 111 and the air valve 112 respectively.

[0028] In the embodiment of the present application, the box body 11 is used to carry wafers. An opening is provided on one side of the box body 11, and a door frame is also provided on the side where the opening is provided. When the door frame is opened, the box body 11 is in an open state, and wafers can be placed therein. When the door frame is closed, the box body 11 is in a closed state, so that the internal environment of the box body 11 is isolated from the production environment of the wafers.

[0029] It is understandable that the box body 11 may include a supporting component inside for supporting the wafer. The outer shape of the box body 11 may be a cuboid to facilitate the transfer of the box body 11. In the embodiment of the present application, the volume of the box body 11 is not limited.

[0030] It should be noted that, since the box body 11 can adjust the pressure inside the box body 11 through the pump valve 111 and the air valve 112, when there is a pressure difference between the inside and outside of the box body 11, the material of the box body 11 can prevent the box body 11 from deforming or deforming to a small extent, thereby avoiding squeezing of the wafers inside the box body 11. The degree of pressure change of the box body 11 is adapted to the pressure bearing degree of the material of the box body 11.

[0031] In an embodiment of the present application, the pneumatic control mechanism 12 can be fixedly arranged near the process equipment that needs to perform crystal transfer. The box body 11 can be placed on the pneumatic control mechanism 12 first, and then the wafer can be placed in the box body 11, so as to adjust the pressure in the box body 11 in time and realize the use of protective gas to purge the wafer in the box body 11.

[0032] In the embodiment of the present application, the box body 11 needs to move back and forth between different process equipment to achieve crystal transfer. Generally, the number of the box bodies 11 is the same as the number of the air pressure control mechanisms 12. Due to the influence of factors such as the wafer processing speed, the number of wafers processed simultaneously, the number of the same processing equipment, the time required to load the wafer, the time required to transfer the wafer, and the time to purge the wafer transfer box, in the actual wafer processing environment, the ratio of the number of the box bodies 11 to the air pressure control mechanisms 12 can be one-to-one, one-to-many, or many-to-one.

[0033] It can be understood that when the quantity ratio of the box body 11 and the air pressure control mechanism 12 is one to many or many to one, the box body 11 matches the size of the air pressure control mechanism 12, and the pump valve 111 and the air valve 112 match the control end of the air pressure control mechanism 12.

[0034] In the embodiment of the present application, the pump valve 111 and the gas valve 112 can be arranged at any position of the box body 11. When the box body 11 is a rectangular parallelepiped, the pump valve 111 and the gas valve 112 can be arranged on any side surface of the box body 11.

[0035] It can be understood that the internal air pressure of the box body 11 can be changed by the pump valve 111 and the gas valve 112. The pump valve 111 is used to extract air from the box body 11 to adjust the pressure in the box body 11, and the gas valve 112 is used to fill the box body 11 with protective gas to adjust the pressure in the box body 11. Through the process of exhausting air and filling protective gas, the inside of the wafer conveyor box can be purged to clean the wafers and exhaust to remove impurities (such as moisture, dust particles, metal ions and volatile organic compounds, etc.) inside the wafer conveyor box, thereby changing the internal gas environment of the box body 11.

[0036] In this way, by controlling the air pressure change of the box body 11, the adhesion viscosity of organic compounds that exist deep in the wafer surface image or evaporate slowly is reduced, the degree of impurity removal inside the wafer transfer box is improved, the wafer defects caused by impurities in the wafer production environment are reduced, and the wafer yield is improved.

[0037] In the embodiments of the present application, Figure 1 As shown, the air pressure control mechanism 12 includes:

[0038] A stage 121, wherein the stage 121 is disposed on one side of the box body 11;

[0039] An exhaust pipe 122, the exhaust pipe 122 is located on the stage 121 and is detachably connected to the pump valve 111;

[0040] An air filling tube 123, the air filling tube 123 is located on the stage 121 and is detachably connected to the air valve 112;

[0041] The controller 124 has a first control terminal electrically connected to the pump valve 111 , and a second control terminal electrically connected to the gas valve 112 .

[0042] In the embodiment of the present application, when the box body 11 is evacuated or inflated, the stage 121 is disposed on one side of the box body 11 to prevent the box body 11 from moving. A clamping component may also be disposed on the stage 121 to further prevent the box body 11 from moving.

[0043] In some embodiments of the present application, a first positioning component is provided on one side of the box body 11; a second positioning component is provided on the stage 121, and the first positioning component is matched with the second positioning component.

[0044] In one example, when the first positioning component is a positioning groove, the second positioning component is a positioning protrusion adapted to the positioning groove.

[0045] In another example, when the first positioning component is a positioning protrusion, the second positioning component is a positioning groove adapted to the positioning protrusion.

[0046] In this way, after the loading platform 121 is disposed on one side of the box body 11 , the first positioning component and the second positioning component define a moving space between each other to prevent the box body 11 from moving on the loading platform 121 .

[0047] In the embodiment of the present application, the exhaust pipe 122 is located on the stage 121, and can be set at any position of the stage 121 without affecting the setting of the box body 11. In the embodiment of the present application, the length of the exhaust pipe 122 is not limited.

[0048] If the stage 121 is disposed on the side of the box body 11 where the pump valve 111 is disposed, the exhaust pipe 122 can be directly connected to the pump valve 111 .

[0049] It is understandable that the diameter of the exhaust pipe 122 is matched with the diameter of the pump valve 111 .

[0050] Similar to the exhaust pipe 122, the inflation pipe 123 is located on the stage 121 and can be set at any position of the stage 121 without affecting the box body 11. In the embodiment of the present application, the length of the inflation pipe 123 is not limited.

[0051] If the loading platform 121 is disposed on the side of the box body 11 where the air valve 112 is disposed, the inflation tube 123 can be docked with the air valve 112 .

[0052] It is understandable that the diameter of the inflation tube 123 is matched with the diameter of the air valve 112 .

[0053] In the embodiment of the present application, the exhaust pipe 122 is detachably connected to the pump valve 111, and the inflation pipe 123 is detachably connected to the gas valve 112, and the specific detachable manner may be a threaded rotation manner. When the exhaust pipe 122 is connected to the pump valve 111, the first control terminal in the controller 124 is electrically connected to the pump valve 111; similarly, when the inflation pipe 123 is connected to the gas valve 112, the second control terminal in the controller 124 is electrically connected to the gas valve 112.

[0054] In order to reduce the impact on the wafer production environment, the exhaust pipe 122 may also be connected to a filtering mechanism to absorb the discharged impurities such as moisture, dust particles, metal ions and volatile organic compounds.

[0055] In the embodiment of the present application, the first control terminal of the controller 124 is electrically connected to the pump valve 111, and the second control terminal of the controller 124 is electrically connected to the gas valve 112. The controller 124 generates and sends valve control instructions to control the opening or closing of the pump valve 111 and the gas valve 112.

[0056] It should be noted that for the same batch of wafers placed in the box body 11, the controller 124 adopts a purge method such as inflating and exhausting at the same time, exhausting-inflating-exhausting, or inflating-exhausting-inflating, to purge the wafers with protective gas. When the exhaust-inflating-exhausting or inflating-exhausting-inflating purge method is adopted, the number of exhausts, the exhaust speed, the amount of gas exhausted at a single time, the number of inflations, and the amount of gas in a single inflation can be determined according to the internal environment of the box body 11, the wafer production environment, or the pressure bearing degree of the material of the box body.

[0057] With respect to the pump valve 111, the air pressure control mechanism 12 controls the pump valve 111 to open, the pump valve 111 draws air from the box body 11, and discharges the internal gas of the box body 11 through the exhaust pipe 122, thereby reducing the pressure in the box body 11 and accelerating the discharge of impurities in the internal gas. When the box body 11 is in a vacuum state or other pumping stop conditions are met, the air pressure control mechanism 12 controls the pump valve 111 to close. Other pumping stop conditions may be that the pressure in the box body 11 reaches a preset threshold, the opening time of the pump valve 111 reaches a preset time, and the pumped gas reaches a preset volume, etc.

[0058] In some embodiments of the present application, the pump valve 111 is a one-way valve to prevent the valve from being incompletely closed during the process of the air pressure control mechanism 12 controlling the pump valve 111, resulting in the backflow of gas from the wafer production environment, causing the box body 11 to be filled with gas containing impurities again, which may lead to insufficient removal of impurities inside the wafer transfer box, and fail to reduce wafer defects caused by impurities in the wafer production environment, thereby failing to improve the wafer yield.

[0059] In some embodiments of the present application, the pump valve 111 is a one-way valve with adjustable flux. The pump valve 111 may include a flux regulating valve, which may be regulated by the air pressure control mechanism 12 or manually. In the embodiments of the present application, the flux regulating method of the flux regulating valve is not limited.

[0060] With respect to the gas valve 112, the air pressure control mechanism 12 controls the gas valve 112 to open, and fills the protective gas into the box body 11 through the gas valve 112. When the gas filling stop condition is met, the air pressure control mechanism 12 controls the gas valve 112 to close. The gas filling stop condition may be that the pressure in the box body 11 reaches a preset threshold, the opening time of the gas valve 112 reaches a preset time, and the filled gas reaches a preset volume, etc.

[0061] In some embodiments of the present application, the gas charging tube 123 is connected to the gas source of the protective gas. After the gas valve 112 is opened, the gas source of the protective gas charges the protective gas into the box body 11 through the gas charging tube 123 and the gas valve 112.

[0062] In some embodiments of the present application, the protective gas is an inert gas, specifically, nitrogen or argon.

[0063] In some embodiments of the present application, the gas valve 112 is a one-way valve to prevent the valve from being completely closed during the process of the air pressure control mechanism 12 controlling the gas valve 112, resulting in the backflow of gas from the wafer production environment, causing the gas source to be filled with gas containing impurities, which may lead to insufficient removal of impurities inside the wafer transfer box, and fail to reduce wafer defects caused by impurities in the wafer production environment, thereby failing to improve the wafer yield.

[0064] In some embodiments of the present application, the gas valve 112 is a one-way valve with adjustable flux. The gas valve 112 may include a flux regulating valve, which may be regulated by the air pressure control mechanism 12 or manually. In the embodiments of the present application, the flux regulating method of the flux regulating valve is not limited.

[0065] In some embodiments of the present application, the air pressure control mechanism also includes: a first pressure sensor arranged in the exhaust pipe, and a second pressure sensor arranged in the inflation pipe; the first pressure sensor and the second pressure sensor are respectively used to detect the internal pressure of the box body.

[0066] Through the first pressure sensor and the second pressure sensor, the internal pressure of the box body 11 can be detected when the pump valve 111 or the air valve 112 is opened, so that the pump valve 111 or the air valve 112 can be opened or closed according to the detected internal pressure of the box body 11 to avoid excessive internal pressure of the box body 11, which may cause damage to the box body 11 or damage to the wafer carried by the box body 11.

[0067] The beneficial effects that may be brought about by the embodiments of the present application include but are not limited to: by controlling the air pressure change of the box body 11, the adhesion and viscosity of organic compounds that exist deep in the wafer surface image or evaporate slowly are reduced, the degree of impurity removal inside the wafer transfer box is improved, the wafer defects caused by impurities in the wafer production environment are reduced, and the wafer yield is improved. Moreover, it is also possible to reduce the impurity removal time, improve the impurity removal efficiency inside the wafer transfer box, reduce the wafer production cycle, and thus improve the wafer production efficiency. In addition, reducing the impurity removal time can reduce the amount of protective gas used, thereby reducing the cost of protective gas.

[0068] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0069] In summary, after reading the contents of this application, those skilled in the art will appreciate that the aforementioned application contents may be presented only in an exemplary manner and may not be restrictive. Although not explicitly stated herein, those skilled in the art will appreciate that this application is intended to encompass various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are within the spirit and scope of the exemplary embodiments of this application.

[0070] It should also be understood that although the terms first, second, third, etc. can be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present application, the first element in some embodiments can be referred to as the second element in other embodiments. The same reference numerals or the same reference signs represent the same elements throughout the specification.

Claims

1. A wafer transfer box, characterized in that: include: A box body, wherein the box body is provided with a pump valve and an air valve, wherein the pump valve is used to extract air from the box body to adjust the pressure in the box body, and the air valve is used to fill the box body with protective gas; An air pressure control mechanism, wherein the air pressure control mechanism is connected to the pump valve and the air valve respectively, and the air pressure control mechanism is used to control the opening or closing of the pump valve and the air valve respectively.

2. The wafer transfer box according to claim 1, characterized in that: The air pressure control mechanism comprises: A loading platform, the loading platform is arranged on one side of the box body; An exhaust pipe, the exhaust pipe is located on the stage and is detachably connected to the pump valve; An air filling tube, the air filling tube is located on the loading platform and is detachably connected to the air valve; A controller, wherein a first control end of the controller is electrically connected to the pump valve, and a second control end of the controller is electrically connected to the gas valve.

3. The wafer transfer box according to claim 2, characterized in that: The gas filling pipe is connected to a gas source of the protective gas.

4. The wafer transfer box according to claim 3, characterized in that: The protective gas is nitrogen or argon.

5. The wafer transfer box according to claim 2, characterized in that: A first positioning component is disposed on one side of the box body; a second positioning component is disposed on the stage, and the first positioning component is matched with the second positioning component.

6. The wafer transfer box according to claim 5, characterized in that: When the first positioning component is a positioning groove, the second positioning component is a positioning protrusion adapted to the positioning groove.

7. The wafer transfer box according to claim 5, characterized in that: When the first positioning component is a positioning protrusion, the second positioning component is a positioning groove adapted to the positioning protrusion.

8. The wafer transfer box according to claim 2, characterized in that: The air pressure control mechanism further includes: a first pressure sensor disposed in the exhaust pipe, and a second pressure sensor disposed in the inflation pipe; the first pressure sensor and the second pressure sensor are both used to detect the internal pressure of the box body.

9. The wafer transfer box according to claim 1, characterized in that: The pump valve is a one-way valve, or the pump valve is a one-way valve with adjustable flux.

10. The wafer transport box according to claim 1, characterized in that: The gas valve is a one-way valve, or the gas valve is a one-way valve with adjustable flux.

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