Phosphoric acid high-temperature cleaning equipment

Abstract

The invention relates to the technical field of wafer cleaning, in particular to phosphoric acid high-temperature cleaning equipment. Comprising a tank body, a condensing device and a covering device, the tank body comprises a circulating tank and a circulating tank shell covering the circulating tank, and the upper part of the circulating tank is open; the condensing device is arranged above the tank body and comprises a frame body and a condensing coil; the covering device comprises a cover body and a driving mechanism; one side of the driving mechanism is connected with the circulating tank shell, and the other side of the driving mechanism is connected with the cover body and can drive the cover body to cover the upper opening of the frame body; the side, facing the condensing device, of the cover body is covered with a PFA film, and a sealing structure is arranged on the edge of the PFA film and used for achieving sealing between the cover body and the frame body. According to the condensing device, the temperature of phosphoric acid steam can be reduced to be lower than the boiling point of the phosphoric acid steam, so that the phosphoric acid steam flows back into the circulating tank, the temperature of phosphoric acid cleaning liquid is kept relatively uniform and stable in the working process, and loss caused by volatilization of phosphoric acid is effectively prevented.

Description

Technical Field

[0001] The present application relates to the technical field of wafer cleaning, and in particular to a phosphoric acid high-temperature cleaning device. Background Art

[0002] In the chip manufacturing process, wafer cleaning is a very critical step. Traditional cleaning methods have limited cleaning effects on some stubborn impurities, especially materials such as silicon nitride. Phosphoric acid has special chemical properties at high temperatures. It can effectively react with silicon nitride on the surface of the wafer to remove it. In addition, the high temperature environment helps to speed up the chemical reaction rate, making the cleaning process more efficient. At the same time, by precisely controlling parameters such as temperature, solution concentration, and cleaning time, it is possible to reduce damage to the wafer material itself on the basis of effectively removing impurities, thereby ensuring the quality and performance of the wafer. The emergence of this technology is also to meet the urgent needs for high precision and high cleanliness in advanced semiconductor manufacturing processes.

[0003] However, phosphoric acid is volatile under high temperature conditions. The volatilized acid mist will cause the loss of cleaning materials and affect the cleaning effect. It will also pollute the surrounding environment and pose certain safety hazards. Summary of the invention

[0004] The present application provides a phosphoric acid high-temperature cleaning device, which can keep the temperature of the phosphoric acid cleaning solution relatively stable during operation, and can also effectively prevent the loss of phosphoric acid by volatilization and avoid the escape of acid mist.

[0005] The phosphoric acid high temperature cleaning equipment provided in the present application comprises a tank body, a condensing device and a covering device;

[0006] The tank body includes a circulation tank for placing phosphoric acid cleaning solution and wafers and a circulation tank shell covering the circulation tank, wherein the top of the circulation tank is open; and further includes a heating device for heating the phosphoric acid cleaning solution in the circulation tank;

[0007] The condensing device is arranged above the tank body, and comprises an annular frame body surrounding the opening, and a condensing coil pipe arranged on the inner surface of the frame body and used for filling a condensing medium;

[0008] The covering device comprises a cover body and a driving mechanism; one side of the driving mechanism is connected to the outer shell of the circulation tank, and the other side is connected to the cover body, and can drive the cover body to cover the upper opening of the frame body;

[0009] The side of the cover body facing the condensing device is covered with a PFA film, and a sealing structure is arranged at the edge of the PFA film to achieve sealing between the cover body and the frame body.

[0010] In a preferred embodiment, the circulation groove comprises an inner circulation groove and an outer circulation groove, the lower edge of the outer circulation groove is sealedly connected to the outer wall of the inner circulation groove, and the upper edge of the outer circulation groove can be hung on the upper edge of the outer shell of the circulation groove;

[0011] The upper edge of the inner circulation groove is lower than the upper edge of the outer circulation groove in the vertical direction, and an overflow cavity is formed between the inner circulation groove and the outer circulation groove. A plurality of overflow ports arranged at intervals are arranged on the upper edge of the inner circulation groove so that excess phosphoric acid can overflow into the overflow cavity.

[0012] In a preferred embodiment, the overflow port is "V"-shaped or "U"-shaped.

[0013] In a preferred embodiment, a fluororubber sealing gasket is provided between the condensing device and the open opening of the circulation tank.

[0014] In a preferred embodiment, the outer wall of the circulation tank is coated with thermal insulation rock wool.

[0015] In a preferred embodiment, two ends of the condensing coil pass through the frame to form a medium inlet and a medium outlet;

[0016] The condensing device further comprises a circulation pump and a heat dissipation device, and the medium inlet, the circulation pump, the heat dissipation device and the medium outlet are sequentially connected to realize the circulation of the condensing medium.

[0017] In a preferred embodiment, the frame is made of quartz material; the condensing coil is a PFA tube, which is arranged on the inner wall of the frame in an annular structure with equal intervals.

[0018] In a preferred embodiment, a plurality of support blocks are arranged between the bottom of the circulation tank and the outer shell of the circulation tank to support the circulation tank.

[0019] In a preferred embodiment, the driving mechanism comprises a cylinder and a rotating shaft; one end of the cylinder is rotatably connected to the outer shell of the circulation tank, and the other end of the cylinder is connected to the rotating shaft through a connecting rod, and the cover is mounted on the rotating shaft;

[0020] When the cylinder is extended or retracted, it can drive the rotating shaft to rotate, thereby driving the cover body to cover or open the upper opening of the frame body.

[0021] In a preferred embodiment, it also includes a controller and a sensor electrically connected to each other;

[0022] The sensor is arranged near the cover body, and is used for detecting the opening and closing state of the cover body, and sending the opening and closing state information of the cover body to the controller.

[0023] This application has the following beneficial effects:

[0024] In the present application, the condensing device can reduce the temperature of the phosphoric acid vapor to below its boiling point, thereby turning it back into liquid and flowing back into the circulation tank, so that the temperature of the phosphoric acid cleaning solution can be kept relatively uniform and stable during the operation, and at the same time, the loss caused by the volatilization of phosphoric acid can be effectively prevented; the covering device can prevent the escape of acid mist, ensure the sealing effect of the equipment, and increase safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is an axonometric schematic diagram of a phosphoric acid high temperature cleaning device provided in an embodiment of the present application;

[0027] Figure 2 is an axonometric schematic diagram of a tank body of a phosphoric acid high temperature cleaning device provided in an embodiment of the present application;

[0028] Figure 3 is a longitudinal cross-sectional view of a tank body of a phosphoric acid high temperature cleaning device provided in an embodiment of the present application;

[0029] Figure 4 is an axonometric schematic diagram of a condensing device of a phosphoric acid high temperature cleaning device provided in an embodiment of the present application;

[0030] Figure 5 is a schematic diagram of a first-perspective axonometric view of a covering device for a phosphoric acid high-temperature cleaning device provided in an embodiment of the present application;

[0031] Figure 6 2 is a schematic diagram of an axonometric view of a covering device for a phosphoric acid high temperature cleaning device provided in an embodiment of the present application from a second perspective;

[0032] Figure 7 It is an isometric schematic diagram of a driving mechanism of a covering device of a phosphoric acid high temperature cleaning device provided in an embodiment of the present application;

[0033] Numbers in the figure:

[0034] 1-tank body; 2-condensing device; 3-covering device;

[0035] 4-support frame; 5-external cylinder connecting rod; 6-cover body;

[0036] 7-first rotating shaft; 8-rotating shaft sleeve; 9-flip cover support;

[0037] 10-cylinder; 11-protection box; 12-first cylinder support plate;

[0038] 13-second cylinder support plate; 14-circulation groove; 141-internal circulation groove;

[0039] 142-external circulation tank; 15-circulation tank housing; 16-support block;

[0040] 17-support plate; 18-frame; 19-fluoro rubber sealing pad;

[0041] 20-condensing coil; 21-coil bracket; 22-cross bar;

[0042] 23-vertical bar; 24-PFA tube; 25-PFA film;

[0043] 26-cylinder frame; 27-cylinder connecting piece; 28-cylinder block seat;

[0044] 29-second rotating shaft; 30-sensor. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and marked in the drawings can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0048] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0049] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0050] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0052] like Figures 1 to 7 As shown, this embodiment discloses a phosphoric acid high temperature cleaning device, including a tank body 1, a condensing device 2 and a covering device 3;

[0053] The tank body 1 includes a circulation tank 14 for placing phosphoric acid cleaning solution and wafers and a circulation tank shell 15 covering the circulation tank 14, and the top of the circulation tank 14 is open; a heating device is also provided on the side wall or bottom of the circulation tank 14, which is used to heat the phosphoric acid cleaning solution inside the circulation tank 14, and can maintain the temperature of the phosphoric acid cleaning solution in the range of 150℃-160℃.

[0054] The circulation tank 14 and the circulation tank shell 15 are made of quartz material, and some flame-retardant PP material is used in the flammable position. The circulation tank 14 includes an inner circulation tank 141 and an outer circulation tank 142. The lower edge of the outer circulation tank 142 is sealed and connected to the outer wall of the inner circulation tank 141, and the upper edge of the outer circulation tank 142 can be hung on the upper edge of the circulation tank shell 15;

[0055] The upper edge of the inner circulation groove 141 is lower than the upper edge of the outer circulation groove 142 in the vertical direction, and an overflow cavity is formed between the inner circulation groove 141 and the outer circulation groove 142. The upper edge of the inner circulation groove 141 is provided with a plurality of "V"-shaped or "U"-shaped overflow ports arranged at intervals, so that excess phosphoric acid can overflow into the overflow cavity, thereby allowing the liquid to flow continuously, so that the solute can be evenly dispersed in the solvent, while also preventing local overheating from causing the liquid to boil and splash, ensuring uniform concentration of the liquid, and preventing local overheating. In addition, the circulating overflow can bring some fixed impurities or bubbles in the liquid to the filter device to be determined, remove impurities and bubbles, and achieve the effect of purifying the liquid.

[0056] In a preferred embodiment, the outer wall of the circulation tank 14 is coated with thermal insulation rock wool, which can effectively slow down the rate of decrease in the temperature inside the tank.

[0057] In a preferred embodiment, sealants are respectively added to the joints inside and outside the tank body 1 to increase the sealing effect of the entire device, prevent acid mist from entering the interior of the device, and increase the service life of the device.

[0058] A plurality of support blocks 16 are arranged between the bottom of the circulation tank 14 and the circulation tank shell 15 to support the circulation tank 14. The support blocks 16 are preferably made of NPP (Nylon-modified Polypropylene), and their arrangement and number are not limited, as long as they can provide stable support for the circulation tank 14.

[0059] The condensing device 2 is arranged above the tank body 1, and the condensing device 2 includes an annular frame 18 surrounding the upper open part of the circulation tank 14, and a plurality of coil brackets 21 are fixedly arranged in the circumferential direction of the inner surface of the frame 18. The condensing coils 20 are installed on the coil brackets 21 in an equally spaced annular structure, thereby forming a disc-shaped cooling area on the inner side of the frame 18.

[0060] The winding method, specification and length of the condensing coil 20 can be in various forms, as long as it can cool down the acid mist in the frame 18 and condense and reflux it.

[0061] A fluororubber sealing pad 19 is provided between the frame 18 and the upper edge of the circulation tank 14 to achieve sealing between the tank body 1 and the condensing device 2 to prevent leakage or escape of the phosphoric acid solution.

[0062] The condensing device 2 and the tank body 1 are also fixedly connected via a plurality of outer cylinder connecting rods 5, so that the connection between the two is more firm and reliable during operation.

[0063] In other embodiments, the condensing device 2 and the tank body 1 may also adopt an integrated design solution, which may reduce the disassembly performance of the device but can fundamentally achieve sealing between the condensing device 2 and the tank body 1 .

[0064] Both ends of the condensing coil 20 pass through the frame 18 to form a medium inlet and a medium outlet; the condensing device 2 also includes a circulation pump and a heat dissipation device, and the medium inlet, circulation pump, heat dissipation device and medium outlet are connected in sequence to realize the circulation of the condensing medium.

[0065] In this embodiment, the frame 18 is made of quartz, the condensing coil 20 is a PFA (perfluoroalkoxy Alkane) material pipe, and the condensing medium is water.

[0066] After the vaporized phosphoric acid enters the condensing device 2, it will be cooled and re-liquefied, and then returned to the circulation tank 14 after liquefaction, ensuring the recycling of phosphoric acid, and effectively suppressing the generation of acid mist, preventing harm to the health and safety of operators, and also maintaining the safety and cleanliness of the working area. The frame 18 is made of quartz material to ensure the cleanliness of the internal space. The cooling water enters the cooling area through the condensing coil 20, which plays a cooling role while ensuring the cleanliness of the interior.

[0067] The covering device 3 includes a cover body 6 and a driving mechanism; one side of the driving mechanism is connected to the circulation tank housing 15, and the other side is connected to the cover body 6, which can drive the cover body to cover the upper opening of the frame body 18.

[0068] The cover body 6 mainly includes a horizontal bar 22, a vertical bar 23, a PFA tube 24, and a PFA film 25. The horizontal bar 22 and the vertical bar 23 are made of NPP material and are connected and fixed by screws to form a cover frame. The PFA tube 24 is pressed into the inner groove of the cover frame, and then the PFA film 25 is pressed onto the PFA tube 24 and fixed with screws.

[0069] Since the PFA film 25 is of high purity and has very low impurity content such as metal ions, it can avoid introducing new impurities during the semiconductor cleaning process. Its chemical corrosion resistance can well resist the acidic reagent of phosphoric acid and prevent the cover from being corroded and damaged. Moreover, this material has a wide temperature resistance range and can work normally at the phosphoric acid solution process temperature of 160°C. The cover body 6 is surrounded by PFA tubes 24 to press the frame 18, which not only plays a sealing role, but also can make full use of the corrosion resistance of the PFA material.

[0070] The horizontal bars 22 and the vertical bars 23 may also be made of materials with similar properties to NPP, such as PVDF, PP, PVC, etc., which can also meet the technical requirements.

[0071] The driving mechanism is arranged on one side of the tank body 1, and includes a cylinder assembly and a rotating shaft assembly. The cylinder assembly includes a protection box 11 arranged on the side of the circulation tank shell 15, a cylinder group seat 28 is fixedly connected to the lower part of the protection box 11, and a first cylinder support plate 12 and a second cylinder support plate 13 are fixedly stacked on the upper part of the protection box 11. The lower end of the cylinder 10 is rotatably connected to the cylinder group seat 28; the upper end of the cylinder 10 is rotatably connected to the cylinder connecting member 27 through the cylinder frame 26, and the cylinder connecting member 27 is rotatably connected to the second rotating shaft 29, and the second rotating shaft 29 is inserted into the mounting holes reserved in the first cylinder support plate 12 and the second cylinder support plate 13.

[0072] The cylinder connecting member 27 is an L-shaped connecting rod, so that when the cylinder 10 is extended or retracted, the second rotating shaft 29 can be driven to rotate.

[0073] The shaft assembly includes a first rotating shaft 7, a shaft sleeve 8 and a flip cover support 9. The flip cover support 9 is fixedly arranged on the circulation tank housing 15, the shaft sleeve 8 is arranged on the flip cover support 9, one end of the first rotating shaft 7 is transmission-connected with the second rotating shaft 29, and the other end is inserted into the shaft sleeve 8.

[0074] The cover body 6 is fixedly connected to the first rotating shaft 7 via a plurality of connecting rods, so that the first rotating shaft 7 can drive the cover body 6 to rotate, so as to cover or open the upper opening of the condensing device 2 .

[0075] In order to make the installation of the protection box 11 more secure, a support frame 4 can also be set on the shell of the circulation tank shell 15, and one end of the support frame 4 extends outward to form a support plate 17, and the protection box 11 can be placed on the support plate 17.

[0076] In addition, the device can also be connected to other devices or systems through the support frame 7.

[0077] In a preferred embodiment, it also includes a controller and a sensor 30 that are electrically connected to each other; the sensor 30 is arranged near the cover body 6, and is used to detect the opening and closing status of the cover body 6, and send the opening and closing status information of the cover body 6 to the controller to increase the safety of the device.

[0078] The sensor 30 may be an optical fiber sensor, and the detection result is sensitive and accurate.

[0079] In the present application, the condensing device can reduce the temperature of the phosphoric acid vapor to below its boiling point, thereby turning it back into liquid and flowing back into the circulation tank, so that the temperature of the phosphoric acid cleaning solution can be kept relatively uniform and stable during the operation, and at the same time, the loss caused by the volatilization of phosphoric acid can be effectively prevented; the covering device can prevent the escape of acid mist, ensure the sealing effect of the equipment, and increase safety.

[0080] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A phosphoric acid high temperature cleaning device, characterized in that: It includes a tank body, a condensing device and a covering device; The tank body includes a circulation tank for placing phosphoric acid cleaning solution and wafers and a circulation tank shell covering the circulation tank, wherein the top of the circulation tank is open; and further includes a heating device for heating the phosphoric acid cleaning solution in the circulation tank; The condensing device is arranged above the tank body, and comprises an annular frame body surrounding the opening, and a condensing coil pipe arranged on the inner surface of the frame body and used for filling a condensing medium; The covering device comprises a cover body and a driving mechanism; one side of the driving mechanism is connected to the outer shell of the circulation tank, and the other side is connected to the cover body, and can drive the cover body to cover the upper opening of the frame body; The side of the cover body facing the condensing device is covered with a PFA film, and a sealing structure is arranged at the edge of the PFA film to achieve sealing between the cover body and the frame body.

2. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: The circulation groove comprises an inner circulation groove and an outer circulation groove, the lower edge of the outer circulation groove is sealedly connected to the outer wall of the inner circulation groove, and the upper edge of the outer circulation groove can be hung on the upper edge of the outer shell of the circulation groove; The upper edge of the inner circulation groove is lower than the upper edge of the outer circulation groove in the vertical direction, and an overflow cavity is formed between the inner circulation groove and the outer circulation groove. A plurality of overflow ports arranged at intervals are arranged on the upper edge of the inner circulation groove so that excess phosphoric acid can overflow into the overflow cavity.

3. The phosphoric acid high temperature cleaning equipment according to claim 2, characterized in that: The overflow port is "V"-shaped or "U"-shaped.

4. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: A fluororubber sealing gasket is arranged between the condensing device and the open opening of the circulation tank.

5. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: The outer wall of the circulation tank is coated with thermal insulation rock wool.

6. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: The two ends of the condensing coil pass through the frame to form a medium inlet and a medium outlet; The condensing device further comprises a circulation pump and a heat dissipation device, and the medium inlet, the circulation pump, the heat dissipation device and the medium outlet are sequentially connected to realize the circulation of the condensing medium.

7. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: The frame is made of quartz material; the condensing coil is a PFA tube, which is arranged on the inner wall of the frame in an annular structure with equal intervals.

8. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: A plurality of support blocks are arranged between the bottom of the circulation tank and the outer shell of the circulation tank to support the circulation tank.

9. The phosphoric acid high temperature cleaning equipment according to claim 1, characterized in that: The driving mechanism comprises a cylinder and a rotating shaft; one end of the cylinder is rotatably connected to the outer shell of the circulation tank, the other end of the cylinder is connected to the rotating shaft through a connecting rod, and the cover is mounted on the rotating shaft; When the cylinder is extended or retracted, it can drive the rotating shaft to rotate, thereby driving the cover body to cover or open the upper opening of the frame body.

10. The phosphoric acid high temperature cleaning equipment according to claim 9, characterized in that: Also included is a controller and a sensor electrically connected to each other; The sensor is arranged near the cover body, and is used for detecting the opening and closing state of the cover body, and sending the opening and closing state information of the cover body to the controller.

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