Wafer cleaning device

Abstract

The embodiment of the utility model provides a wafer cleaning device which comprises the components of a housing which is provided with a chamber and is provided with a first end and a second end which are oppositely arranged; the first end is provided with a first opening, and the second end is provided with a second opening; the carrying table is arranged at the first opening and is used for carrying a wafer; the clamp structure is arranged at the first end and is used for clamping the carrying table at the first opening; the carrying platform also seals the first opening; the cleaning unit is arranged at the position of the shell; and the air draft system is arranged between the cleaning unit and the second opening, is close to the second opening and is used for providing cyclone to discharge and collect foreign matters cleaned by the cleaning unit. According to the wafer cleaning device provided by the embodiment of the invention, the back surface of the wafer can be cleaned, and the wafer utilization rate is improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, in particular to a wafer cleaning device. Background Art

[0002] At present, Metal Oxide Semiconductor (MOS) field effect transistors have been widely used in the semiconductor field; especially in smart cards, Radio Frequency Identification (RFID) devices, new mobile phones and other small, lightweight and powerful electronic devices, and the requirements for the production of semiconductor devices are higher accordingly.

[0003] However, in the actual process of production, the wafers are contaminated, resulting in a decrease in the utilization rate of wafers. Therefore, how to provide a technical solution to clean the wafers to improve the utilization rate of wafers has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Utility Model

[0004] The technical problem solved by the utility model is to provide a wafer cleaning device to clean the back of the wafer so as to improve the utilization rate of the wafer.

[0005] To solve the above problems, an embodiment of the utility model provides a wafer cleaning device, including:

[0006] A housing having a chamber, the housing having a first end and a second end disposed opposite to each other; the first end is provided with a first opening, and the second end is provided with a second opening; a stage disposed at the first opening for carrying a wafer; a fixture structure disposed at the first end for clamping the stage at the first opening; the stage also seals the first opening; a cleaning unit disposed at the housing; and an exhaust system disposed between the cleaning unit and the second opening, near the second opening, for providing a return cyclone to discharge and collect foreign matters cleaned out by the cleaning unit.

[0007] Optionally, the size of the stage is greater than or equal to the size of the first opening, and the size of the first opening is greater than or equal to the size of the wafer; the housing and the stage carrying the wafer form a semi-closed space.

[0008] Optionally, the number of the fixture structures is at least 3.

[0009] Optionally, it further includes: a sensor disposed on the housing or the fixture structure for detecting the position of the wafer.

[0010] Optionally, the cleaning unit includes: a gas supply system disposed inside or outside the housing, providing dry air and ion wind; a porous structure disposed on the inner wall of the housing; an air outlet disposed on the porous structure for blowing the dry air and ion wind provided by the gas supply system to the back surface of the wafer; a filter for removing foreign matters mixed in the gas supply system; a regulating valve for controlling the blowing flow rate and blowing air pressure of the dry air and ion wind; wherein, the filter is disposed between the gas supply system and the regulating valve, and the regulating valve is disposed between the filter and the porous structure.

[0011] Optionally, it further includes: an adjusting structure for adjusting the position of the porous structure along the inner wall of the housing.

[0012] Optionally, the blowing direction of the air outlet is: along the edge of the back surface of the wafer and obliquely towards the center of the wafer.

[0013] Optionally, the air outlet is circular or square; the number of the air outlets is at least two.

[0014] Optionally, the shape of the housing is a cylindrical structure.

[0015] Optionally, the porous structure is a circular ring, and the diameter is greater than or equal to 300 mm; the blowing flow rate is not less than 30 m / s and not greater than 100 m / s; the blowing air pressure is not less than 0.5 Mpa and not greater than 3 Mpa.

[0016] In an embodiment of the present invention, a carrier for carrying a wafer is disposed at the first opening of the housing, and the carrier seals the first opening; between the cleaning unit and the second opening, an air extraction system is disposed near the second opening, so that the swirling wind force formed between the air extraction system and the cleaning unit is stronger. Thus, on the one hand, the cleaning effect of the cleaning unit on the back surface of the wafer is improved, and on the other hand, it is beneficial to discharge and collect foreign matters cleaned by the cleaning unit, prevent secondary contamination of the wafer, and improve the utilization rate of the wafer. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0018] Figure 1 is a schematic structural diagram of a wafer cleaning device according to an embodiment of the present invention;

[0019] Figure 2 is a top view of the combination of the housing and the porous structure according to an embodiment of the present invention;

[0020] Figure 3 is a top view of the combination of the housing and the porous structure according to another embodiment of the present utility model;

[0021] Figure 4 is a schematic diagram of the porous structure according to an embodiment of the present utility model;

[0022] Figure 5 is a schematic diagram of the relationship between the purging direction of the air outlet of the porous structure and the position of the wafer according to an embodiment of the present utility model. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0024] During the manufacturing process of semiconductor devices, most of the robotic arms and carriers use vacuum adsorption to transfer and transport wafers in order to perform processes such as film formation, coating, etching, and degluing. Before these processes, the front side (device side) of the semiconductor wafer is cleaned, but the cleaning of the back side (non-device side) of the wafer is ignored. In the actual manufacturing process, the robotic arm for transferring and transporting the wafer and / or the carrier for carrying the wafer are prone to accumulate crystal dust or oil stains after long-term use, which increases the risk of contamination of the back side of the wafer and may cause insufficient vacuum adsorption force on the robotic arm and / or the carrier. Specifically, first, when the robotic arm transfers the wafer, it is easy to cause the position of the wafer to shift, resulting in the wafer slipping and breaking, reducing the utilization rate of the wafer; second, when the carrier for carrying the wafer moves and scans, it is easy to cause the wafer to be thrown out and broken, also reducing the utilization rate of the wafer.

[0025] In view of the above technical problems, the embodiment of the present utility model provides a wafer cleaning device, which can clean the back side of the wafer to improve the utilization rate of the wafer.

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model Figures 1 to 5 , and the technical solutions in the embodiments of the present utility model will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0027] Refer to Figure 1, an embodiment of the present utility model provides a wafer cleaning device, including: a housing 100 having a chamber, the housing 100 having a first end 102 and a second end 104 disposed opposite to each other; a first opening K1 provided at the first end 102, and a second opening K2 provided at the second end 104; a stage ZT disposed at the first opening K1 for carrying a wafer; a fixture structure 106 disposed at the first end 102 for clamping the stage ZT at the first opening K1; the stage ZT also sealing the first opening K1; a cleaning unit 108 disposed at the housing 100; and an exhaust system 110 disposed between the cleaning unit 108 and the second opening K2, near the second opening K2, for providing a return cyclone F to discharge and collect foreign matters cleaned out by the cleaning unit 108.

[0028] Using the above wafer cleaning device, the back surface of the wafer can be cleaned in the following manner:

[0029] The stage ZT loaded with the wafer is disposed at the first opening K1 through the fixture structure 106, and the stage ZT loaded with the wafer seals the first opening K1; the cleaning unit 108 and the exhaust system 110 disposed at the housing 100 start to work, the cleaning unit 108 cleans the back surface of the wafer, and forms a return cyclone F with the exhaust system 110 to discharge the foreign matters cleaned out by the cleaning unit 108, and the exhaust system 110 collects the discharged foreign matters at the same time; the cleaned wafer is taken away.

[0030] In summary, during the manufacturing process of semiconductor devices, first, by means of the cleaning unit 108 and the exhaust system 110 disposed at the housing 100, foreign matters (such as crystal dust) and / or oil stains attached to the back surface of the wafer are cleaned and removed, improving the cleanliness of the back surface of the wafer, reducing the probability of insufficient vacuum adsorption force of the robotic arm and / or the stage ZT for transporting and conveying the wafer caused by foreign matters and / or oil stains, and reducing the risk of the wafer slipping and breaking or being thrown out and broken, thereby improving the utilization rate of the wafer; second, the cleaning process is completed inside the housing, reducing the probability of the foreign matters cleaned out by the cleaning unit 108 polluting the process environment and / or damaging the production equipment.

[0031] Continue to refer to Figure 1, the housing 100 is in the shape of a columnar structure; the material of the housing includes a metal material (such as stainless steel, aluminum, etc.) or an anti-static plastic material (such as polycarbonate, electro-polypropylene, acrylic, etc.); the columnar structure includes any one of the following: a cylindrical structure, an elliptical cylindrical structure, a square columnar structure, etc. The embodiments of the present application do not limit the material of the housing 100 and the specific columnar structure, and those skilled in the art can adjust and set according to the actual situation. It should be noted that, for the sake of simplicity and clarity of the drawings, the housing 100 in all embodiments of the present invention is exemplified by a cylindrical structure, but the present application should not be limited thereto.

[0032] Continue to refer to Figure 1 , the housing 100 has a first end 102 and a second end 104 which are oppositely arranged; the first end 102 is provided with a first opening K1 to expose the back surface of the wafer to be cleaned; the second end 104 is provided with a second opening K2 to facilitate the cleaning of foreign matters, the adjustment and maintenance of the cleaning device.

[0033] The first end 102 may be provided with all openings or partial openings, and the second end 104 may be provided with all openings or partial openings; the all openings are formed by completely removing the housing material at the first end 102 and the second end 104; the partial openings are formed by partially removing the housing material at the first end 102 and the second end 104; the embodiments of the present application do not limit whether the first opening K1 and the second opening K2 are all openings or partial openings.

[0034] The shape of the first opening K1 and / or the second opening K2 includes any one of the following: circular, square, triangular, irregular opening shape; in this embodiment, the shape of the first opening K1 and the second opening K2 is not limited, as long as the back surface of the wafer to be cleaned can be exposed; for the sake of simplicity and clarity of the drawings, in all embodiments of the present invention, the first opening K1 is a partial opening and the shape is circular, and the second opening K2 is an all opening and the shape is circular for example, but the present application should not be limited thereto.

[0035] Continue to refer to Figure 1 , the wafer cleaning device may include a carrier ZT disposed at the first opening K1 for carrying the wafer.

[0036] In this embodiment, the size of the stage ZT is greater than or equal to the size of the first opening K1, and the size of the first opening K1 is greater than or equal to the size of the wafer, so that the back surface of the wafer is completely exposed within the cleaning range of the cleaning unit 108. The exhaust system 110 and the cleaning unit 108 can clean the back surface of the wafer more comprehensively. In some other embodiments (for example, for a thinned wafer: the thickness of the wafer edge region is greater than the thickness of the thinned region), the size of the stage ZT is greater than or equal to the size of the first opening K1, and the size of the first opening K1 is greater than or equal to the size of the thinned region of the wafer. Those skilled in the art can adjust the size of the first opening K1 according to the actual situation to expose the part of the back surface of the wafer to be cleaned.

[0037] Continuing to refer to Figure 1 , the wafer cleaning device may include a fixture structure 106 disposed at the first end 102 for clamping the stage ZT at the first opening K1; the stage ZT also seals the first opening K1.

[0038] In this embodiment, the fixture structure 106 is used to clamp the stage ZT loaded with the wafer at the first opening K1, that is, to fix the stage ZT loaded with the wafer at the first opening K1 at the first end 102 of the housing 100; the fixture structure 106 has functions such as position adjustment, clamping, and loosening; before the cleaning unit 108 cleans the wafer, the fixture structure 106 adjusts the position of the stage ZT loaded with the wafer at the first opening K1 to expose the back surface of the wafer to be cleaned; when the cleaning unit 108 cleans the back surface of the wafer, the fixture structure 106 clamps the stage ZT loaded with the wafer to fix the wafer without sliding; after the cleaning unit 108 stops cleaning, the fixture structure 106 loosens the wafer stage ZT to facilitate the removal of the wafer with the back surface cleaning completed.

[0039] The number of the fixture structures 106 is at least 3. In this embodiment, the number of the fixture structures 106 is 4.

[0040] In this embodiment, the stage ZT also seals the first opening K1; the housing 100 and the stage ZT carrying the wafer form a semi-closed space, and the advantages are as follows: First, the dry air provided by the air supply system 114 has a stronger blowing force when purging the back of the wafer, improving the cleaning effect of the cleaning unit 108 on the back of the wafer; Second, a better cyclone wind (such as a stronger swirling wind) can be formed between the cleaning unit 108 and the exhaust system 110, which is beneficial to discharging and collecting the foreign matters cleaned by the cleaning unit 108 and preventing secondary contamination of the wafer, thereby improving the wafer utilization rate; Third, the cleaning process is carried out inside the housing 100, reducing the probability of the foreign matters cleaned by the cleaning unit 108 contaminating the process environment and / or damaging the production equipment. In another embodiment, a sealing ring (such as a rubber pad) is provided between the stage ZT and the first opening K1 to further seal the first opening K1 by the stage ZT loaded with the wafer.

[0041] Continue to refer to Figure 1 , the wafer cleaning device further includes: a sensor 112 disposed on the housing 100 or the fixture structure 106 for detecting the position of the wafer, that is, detecting whether the back of the wafer to be cleaned is exposed within the cleaning range of the cleaning unit 108. In this embodiment, the wafer position sensor 112 is disposed on the fixture structure 106. The sensor 112 is an optoelectronic sensor and detects based on the principle of converting an optical signal into an electrical signal. In some other embodiments, the sensor 112 is disposed on the housing 100 or outside the housing 100.

[0042] Continue to refer to Figure 1 , the wafer cleaning device includes: a cleaning unit 108 disposed at the housing 100; the cleaning unit 108 is used for cleaning the back of the wafer.

[0043] In this embodiment, a part of the cleaning unit 108 is disposed inside the housing 100 and a part is disposed outside the housing 100. In some other embodiments, the cleaning unit 108 is entirely located inside the housing 100.

[0044] Continue to refer to Figure 1 , the cleaning unit 108 includes: an air supply system 114 disposed inside or outside the housing 100 for providing dry air and ion wind; in this embodiment, the air supply system 114 is located outside the housing 100. The air supply system 114 provides dry air for purging the foreign matters on the back of the wafer; the ion wind provided by the air supply system 114 is used to neutralize the static electricity in the process, reducing the damage of the static electricity to the wafer.

[0045] In this embodiment, the dry air and the ion wind are mixed and purged from the air outlet to the back of the wafer; in some other embodiments, the dry air and the ion wind can be purged separately to the back of the wafer.

[0046] Reference Figure 1 、 Figure 2 and Figure 3 , the cleaning unit 108 includes: a porous structure 116 disposed on the inner wall of the housing 100.

[0047] In this embodiment, the material of the porous structure 116 includes a metal material (such as stainless steel, aluminum, etc.) or an antistatic plastic material (such as polycarbonate, electropropylene, acrylic, etc.).

[0048] In this embodiment, the porous structure 116 is a circular ring. In another embodiment, the porous structure includes a square ring column.

[0049] In this embodiment, the porous structure 116 is disposed on the inner wall of the housing 100; the porous structure 116 is placed between the first end 102 of the housing 100 and the exhaust system 110. In some other embodiments, the first end 102 of the housing 100, the exhaust system 110, and the porous structure 116 can be arranged in this order, and at this time, the porous structure 116 can be located between the exhaust system 110 and the second end 104.

[0050] In this embodiment, the porous structure 116 is a circular ring, and the diameter is greater than or equal to 300 mm (millimeter ) .

[0051] In this embodiment, there is a distance d1 between the porous structure 116 and the housing 100, which is used to reduce the probability that foreign matters cleaned by the cleaning unit 108 remain between the porous structure 116 and the housing 100 and cause secondary contamination to the wafer. In some other embodiments, different combinations of the shapes of the housing 100 and the porous structure 116 are used to reduce the probability that foreign matters remain between the porous structure 116 and the housing 100. Figure 2 is a top view of the combination of the housing and the porous structure of an embodiment, as Figure 2 shown, the housing 100 is a circular cylinder, the porous structure 116 is a square cylinder, and the circular cylinder is circumscribed to the square cylinder. Figure 3 is a top view of the combination of the housing and the porous structure of another embodiment, as Figure 3 shown, the housing 100 is a square cylinder, the porous structure 116 is a circular ring, and the circular ring is inscribed in the square cylinder. The foreign matters cleaned by the cleaning unit 108 can be discharged from the Figure 2 gap S1 in Figure 3 or the gap S2 in

[0052] Reference Figure 1 、 Figure 4 andFigure 5 , Figure 4 is an exemplary diagram of a porous structure. Figure 5 is a schematic diagram showing the relationship between the purge direction of the air outlet of the porous structure and the wafer position. The cleaning unit 108 includes: an air outlet 118 disposed on the porous structure 116 for purging the dry air and ion wind provided by the gas supply system 114 to the back surface of the wafer.

[0053] The air outlet 118 is circular or square; in this embodiment, the air outlet 118 is circular.

[0054] The number of the air outlets is at least 2; in this embodiment, the number of the air outlets is 8.

[0055] As Figure 4 and Figure 5 shown, the air outlets 118 can be evenly distributed on the porous structure 116; the orientation of the air outlets 118 can be an oblique orientation towards the center of the wafer; the purge direction M of the air outlets 118 is: along the edge of the back surface of the wafer O and obliquely towards the center of the wafer; that is, the air outlets 118 purge along the wafer edge towards the wafer center. The purge direction M of the air outlets 118 forms an angle J with the perpendicular line B1B2 on the surface of the wafer O, and the value of the angle J is adjustable; in this embodiment, the angle J between the purge direction M of the air outlets 118 and the perpendicular line B1B2 on the wafer surface can be not less than 0 degrees and not more than 90 degrees.

[0056] Continuing to refer to Figure 1 , the cleaning unit 108 includes: a filter 120 for removing foreign matters mixed in the gas supply system 114; the filter 120 is used to reduce the probability of the foreign matters clogging the air outlet 118 of the porous structure 116, or reduce the possibility of the foreign matters mixed in the dry air and accelerated by the gas supply system 114 damaging the wafer.

[0057] In this embodiment, the filter 120 is disposed between the gas supply system 114 and the regulating valve 122, which can prevent the foreign matters in the gas supply system from clogging or damaging the regulating valve. In some other embodiments, at least one filter 120 is disposed between the regulating valve and the porous structure 116 to further remove the foreign matters mixed in the dry air.

[0058] It should be noted that there are two sources of the foreign matters mixed in the gas supply system 114: First, from the dry air. For example, before the dry air enters the gas supply system, minute particles such as dust and fibers in the external environment are mixed in the dry air; Second, from the gas supply system 114. For example, during the operation of the equipment in the gas supply system 114, wear particles may be generated and mixed in the dry air output by the gas supply system.

[0059] Continuing to refer to Figure 1, the cleaning unit 108 includes: a regulating valve 122 for controlling the blowing flow rate and blowing air pressure of dry air and ion wind; the regulating valve 122 is disposed between the filter 120 and the porous structure 116.

[0060] In this embodiment, the regulating valve 122 is disposed between the filter 120 and the porous structure 116 and is close to the porous structure 116, which can enable the dry air and ion wind to form a strong wind force through the porous structure 116, enhancing the cleaning effect.

[0061] In this embodiment, the regulating valve 122 is composed of components such as a valve body, a valve core, and a spring, and the size of the air flow channel is changed by adjusting the position of the valve core, thereby realizing the control of the air pressure and air flow.

[0062] It should be noted that the blowing flow rate and blowing air pressure should not be too large, as it is easy to damage the wafer, especially the thinned wafer; the blowing flow rate and blowing air pressure should not be too small, otherwise the cleaning effect cannot be achieved. In this embodiment, the blowing flow rate is not less than 30 m / s (meters per second) and not greater than 100 m / s; the blowing air pressure is not less than 0.5 Mpa (megapascals) and not greater than 3 Mpa.

[0063] Continue to refer to Figure 1 and Figure 4 , the wafer cleaning device further includes: an adjusting structure (not shown) for adjusting the position of the porous structure 116 along the inner wall of the housing 100. The adjusting structure is used to adjust the different positions of the porous structure 116 on the inner wall of the housing 100 to adapt to wafers of different sizes; at the same time, it is convenient to adjust the distance between the porous structure 116 and the wafer, and it is convenient to adjust the angle between the air outlet 118 on the porous structure 116 and the central vertical line of the wafer surface to achieve the best cleaning effect.

[0064] The adjusting structure includes an automatic control system and a rotating structure, and the automatic control system drives the rotating structure to drive the movement of the porous structure 116.

[0065] It should be noted that the exhaust system 110 is disposed between the cleaning unit 108 and the second opening K2, close to the second opening K2, to prevent the exhaust system 110 from affecting the wind force intensity of the dry air blown by the air outlet 118 to clean the wafer and improve the cleaning effect.

[0066] In this embodiment, the dry air at the air outlet 118 blows from the position F0 to the back surface position F1 of the wafer, forming a return swirling wind F with the gas F2 provided by the exhaust system 110, discharging the foreign matters cleaned by the cleaning unit 108, and collecting them in the exhaust system 110.

[0067] Although the present utility model has been disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above without departing from the spirit and scope of the present utility model. Therefore, all contents that do not depart from the technical solution of the present utility model, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present utility model, shall fall within the protection scope of the technical solution of the present utility model.

Claims

1. A wafer cleaning device, characterized in that, Comprising: A housing having a chamber, the housing having a first end and a second end disposed opposite to each other; the first end is provided with a first opening, and the second end is provided with a second opening; A stage disposed at the first opening for carrying a wafer; A fixture structure disposed at the first end for clamping the stage at the first opening; the stage also seals the first opening; A cleaning unit disposed at the housing; An exhaust system disposed between the cleaning unit and the second opening, near the second opening, for providing a return swirling air to discharge and collect foreign matters cleaned out by the cleaning unit.

2. The cleaning device according to claim 1, wherein The size of the stage is greater than or equal to the size of the first opening, and the size of the first opening is greater than or equal to the size of the wafer; The housing and the stage carrying the wafer form a semi-closed space.

3. The cleaning device according to claim 1, characterized in that, The number of the fixture structures is at least 3.

4. The cleaning device according to claim 1, wherein Further comprising: A sensor disposed on the housing or the fixture structure for detecting the position of the wafer.

5. The cleaning device according to claim 1, characterized in that, The cleaning unit includes: An air supply system disposed inside or outside the housing for providing dry air and ion wind; A porous structure disposed on the inner wall of the housing; An air outlet disposed on the porous structure for blowing the dry air and ion wind provided by the air supply system to the back surface of the wafer; A filter for removing foreign matters mixed in the air supply system; A regulating valve for controlling the blowing flow rate and blowing air pressure of the dry air and ion wind; Wherein, the filter is disposed between the air supply system and the regulating valve, and the regulating valve is disposed between the filter and the porous structure.

6. The cleaning device according to claim 5, characterized in that, Further comprising: An adjusting structure for adjusting the position of the porous structure along the inner wall of the housing.

7. The cleaning device according to claim 5, characterized in that, The blowing direction of the air outlet is: along the edge of the back surface of the wafer and obliquely towards the center of the wafer.

8. The cleaning device according to claim 5, wherein, The air outlet is circular or square; the number of the air outlets is at least 2.

9. The cleaning device according to claim 1, wherein, The shape of the housing is a cylindrical structure.

10. The cleaning device according to claim 5, wherein, The porous structure is a circular ring, and the diameter is greater than or equal to 300 mm; the blowing flow rate is not less than 30 m / s and not greater than 100 m / s; the blowing air pressure is not less than 0.5 Mpa and not greater than 3 Mpa.

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