A drying device for silicon carbide wafer after cleaning

Abstract

This invention provides a drying device for silicon carbide wafers after cleaning, comprising a drying body and a drying mechanism, the drying mechanism being disposed within the drying body. The drying body includes a first drying section and a second drying section. The first drying section contains a first chamber, and the second drying section contains a second chamber communicating with the first chamber. The drying mechanism includes at least a lifting assembly and a spraying assembly. The lifting assembly is used to lift and lower a basket loaded with silicon carbide wafers. The spraying assembly includes a spray cover and a spray pipe, the spray pipe communicating with the spray cover. The spray cover is positioned over the top of the first chamber, and the spray cover has multiple evenly distributed spray holes for spraying a mixed mist of IPA and N2 to dry the silicon carbide wafers. This device can more comprehensively cover the surface of the silicon carbide wafers, avoiding localized moisture residue due to uneven spraying, improving drying consistency, and thus further improving the yield of silicon carbide wafer cleaning and drying.

Description

Technical Field

[0001] This utility model belongs to the field of silicon carbide wafer cleaning technology, and specifically relates to a drying device for silicon carbide wafers after cleaning. Background Technology

[0002] After RCA cleaning, wafers must be dried. With the development of semiconductor technology, drying technology has been upgraded from traditional Spin Dry and IPA (isopropyl alcohol) drying to Marangoni drying. This drying technology greatly reduces the amount of IPA used and is more environmentally friendly.

[0003] In actual use, PFA baskets are used to carry silicon carbide wafers into RCA cleaning. After cleaning, the silicon carbide wafers are transported to the drying unit for drying. Then, a mixed mist of IPA and N2 is sprayed through 2 to 5 spray pipes to replace the water on the wafer surface. Then, heated N2 is blown to dry the silicon carbide wafers. However, the mixed mist of IPA and N2 is very prone to uneven spraying during the spraying process, resulting in water stains remaining on the wafer surface. Utility Model Content

[0004] In view of this, the purpose of this utility model is to provide a drying device for silicon carbide wafers after cleaning, which can effectively avoid the phenomenon of local moisture residue on silicon carbide wafers due to uneven spraying, improve the consistency of drying, and thus improve the yield of silicon carbide wafer cleaning and drying.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A drying apparatus for silicon carbide wafers after cleaning includes a drying body and a drying mechanism, wherein the drying mechanism is disposed within the drying body;

[0007] The drying body includes a first drying section and a second drying section. The first drying section has a first chamber, and the second drying section has a second chamber that communicates with the first chamber.

[0008] The drying mechanism includes at least a lifting assembly and a spraying assembly. The lifting assembly is used to lift and lower the basket loaded with silicon carbide wafers. The spraying assembly includes a spray cover and a spray pipe. The spray pipe is connected to the spray cover. The spray cover is placed on the top of the first chamber. The spray cover has multiple evenly distributed spray holes for spraying a mixed mist of IPA and N2 to dry the silicon carbide wafers.

[0009] Optionally, the lifting assembly includes a snap-fit ​​unit, a lifting robotic arm, and a wafer support unit. The snap-fit ​​unit is connected to the lifting robotic arm, and the wafer support unit is disposed on the lifting robotic arm.

[0010] Optionally, the latching unit includes a first latching part and a second latching part, and the lifting robotic arm is disposed between the first latching part and the second latching part;

[0011] The first snap-fit ​​part is provided with a first snap-fit ​​post, and the second snap-fit ​​part is provided with a second snap-fit ​​post. The first snap-fit ​​post and the second snap-fit ​​post are respectively used to engage with the slots on both sides of the bottom of the flower basket.

[0012] Optionally, the lifting robotic arm includes a first drive motor and a lifting arm body. The motor mount of the first drive motor is disposed outside the drying body, and the motor shaft of the first drive motor is disposed inside the drying body and connected to the lifting arm body. The first drive motor can drive the lifting arm body to move vertically inside the drying body.

[0013] Optionally, the wafer support unit includes a top blade, a top blade rod, a lead screw, and a second drive motor. The top blade is connected to the top blade rod, the top blade rod has a cavity, and the lead screw is disposed in the cavity.

[0014] The inner wall of the cavity is provided with a first thread, and the lead screw is provided with a second thread that mates with the first thread. The second drive motor is connected to the lead screw.

[0015] Optionally, the motor mount of the second drive motor is disposed outside the drying body, and the motor rod of the second drive motor is connected to the lead screw.

[0016] Optionally, the flower basket is made of PFA material;

[0017] The flower basket includes a main frame, horizontal ribs and vertical ribs, and there are multiple vertical ribs, which are arranged on the main frame;

[0018] There are at least two horizontal ribs, which are perpendicular to the vertical ribs. The distance between each horizontal rib and the top of the flower basket is no more than 1 / 2 of the height of the flower basket.

[0019] Optionally, a drain valve is also provided at the bottom of the second chamber, and the drain valve has a drainage speed of 0.8m / s to 2m / s.

[0020] Optionally, the number of injection holes is 200-500.

[0021] Optionally, the total jet flow rate of the jet orifice is 20 L / min-30 L / min.

[0022] As can be seen from the above technical solution, when drying silicon carbide wafers after RCA cleaning, the lifting assembly first raises the basket containing the silicon carbide wafers to a preset height. At this time, the spray assembly is activated, and the mixed mist of IPA and N2 enters the spray cover from the spray pipe, and then is sprayed onto the silicon carbide wafer through the spray holes of the spray cover. Since IPA has strong hydrophilicity and is miscible with water, when the mixed mist of IPA and N2 is sprayed onto the surface of the silicon carbide wafer, it can quickly replace the water adhering to the surface of the silicon carbide wafer. The Marangoni effect (the flow phenomenon caused by the difference in surface tension of liquids) is used to promote the removal of water from the wafer surface and reduce water stains. Among them, the setting of multiple spray holes on the spray cover, compared with the existing single spray pipe or few spray pipe spray structure, can more comprehensively cover the surface of the silicon carbide wafer, avoid local water residue caused by uneven spraying, improve the consistency of drying, and thus further improve the yield of silicon carbide wafer cleaning and drying. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the drying apparatus for cleaning silicon carbide wafers disclosed in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the lifting assembly disclosed in the embodiments of this utility model;

[0026] Figure 3 This is a schematic diagram of the structure of a flower basket containing a wafer placed in a snap-fit ​​unit, as disclosed in an embodiment of the present utility model.

[0027] Figure 4 This is a schematic diagram of the structure of a flower basket containing wafers being immersed in a water tank in the second chamber, as disclosed in an embodiment of the present utility model.

[0028] Figure 5 A schematic diagram of the structure of a flower basket loaded with wafers being lifted by a wafer support mechanism, as disclosed in an embodiment of this utility model.

[0029] Figure 6 This is a schematic diagram of the structure of the flower basket disclosed in the embodiment of this utility model;

[0030] Figure 7 This is a front view of the flower basket disclosed in the embodiment of this utility model;

[0031] Figure 8 This is a top view of the spray assembly disclosed in the embodiment of this utility model.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100. First drying section; 101. First chamber;

[0034] 200 - Second drying section; 201 - Second chamber; 202 - Drain valve;

[0035] 300. First locking part; 301. First locking post;

[0036] 400. Second locking part; 401. Second locking post;

[0037] 500. Lifting robotic arm;

[0038] 600, Knob;

[0039] 700, Wafer Support Unit;

[0040] 800. Spray assembly; 801. Spray cover plate; 8011. Spray orifice; 802. Spray pipe;

[0041] 900. Flower basket; 901. Main frame; 902. Horizontal ribs; 903. Vertical ribs;

[0042] 1000, silicon carbide wafer. Detailed Implementation

[0043] In view of this, the core of this utility model is to provide a drying device for silicon carbide wafers after cleaning, which can effectively avoid the phenomenon of local moisture residue on silicon carbide wafers due to uneven spraying, improve the consistency of drying, and thus improve the yield of silicon carbide wafer cleaning and drying.

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model. Please refer to... Figures 1 to 8 .

[0045] Please refer to this. Figure 1 The drying apparatus for cleaning silicon carbide wafers disclosed in this embodiment of the present invention includes a drying body and a drying mechanism, wherein the drying mechanism is disposed within the drying body.

[0046] The drying body specifically includes a first drying section 100 and a second drying section 200. The first drying section 100 is provided with a first chamber 101, and the second drying section 200 is provided with a second chamber 201 that communicates with the first chamber 101.

[0047] The drying mechanism includes at least a lifting assembly and a spraying assembly 800. The lifting assembly is used to lift the basket 900 containing the silicon carbide wafer 1000. The spraying assembly 800 includes a spraying cover plate 801 and a spraying pipe 802. The spraying pipe 802 is connected to the spraying cover plate 801. The spraying cover plate 801 is placed on the top of the first chamber. The spraying cover plate 801 has a plurality of evenly distributed spraying holes 8011 for spraying a mixed mist of IPA and N2 to dry the silicon carbide wafer 1000.

[0048] When drying the silicon carbide wafer 1000 after RCA cleaning, the basket 900 containing the silicon carbide wafer 1000 is first raised to a preset height using a lifting assembly. At this point, the spray assembly 800 is activated, and a mixed mist of IPA and N2 enters the spray cover plate 801 from the spray pipe 802, and is then sprayed onto the silicon carbide wafer 1000 through the spray holes 8011 of the spray cover plate 801. Due to the IPA... With strong hydrophilicity, it is miscible with water. Therefore, when the mixed mist of IPA and N2 is sprayed onto the surface of the silicon carbide wafer 1000, it can quickly replace the water adhering to the surface of the silicon carbide wafer 1000. Utilizing the Marangoni effect (the flow phenomenon caused by the difference in surface tension of liquids), it promotes the removal of water from the wafer surface and reduces water stains. In particular, the multiple spray holes 8011 on the spray cover plate 801, compared with the existing single spray pipe or few spray pipe spray structures, can more comprehensively cover the surface of the silicon carbide wafer 1000, avoid local water residue caused by uneven spraying, improve the consistency of drying, and thus further improve the yield of cleaning and drying of silicon carbide wafer 1000.

[0049] It should be explained that IPA stands for isopropyl alcohol, a colorless, volatile organic solvent with good hydrophilicity and detergency. It has a boiling point of about 82.4°C and is miscible with solvents such as water and ethanol; N2 stands for nitrogen.

[0050] This utility model embodiment does not limit the specific structure of the lifting component. Any structure that meets the usage requirements of this utility model is within the protection scope of this utility model.

[0051] As one embodiment, please refer to Figure 1 and Figure 2The lifting assembly disclosed in this embodiment of the utility model includes a snap-fit ​​unit, a lifting mechanical arm 500 and a wafer support unit 700. The snap-fit ​​unit is connected to the lifting mechanical arm 500, and the wafer support unit 700 is disposed on the lifting mechanical arm 500.

[0052] When drying the silicon carbide wafer 1000, the basket 900 containing the wafer can be placed on the snap-fit ​​unit inside the drying body. This arrangement ensures the stability of the basket 900. By activating the lifting robotic arm 500, the snap-fit ​​unit and the wafer support unit 700 can be raised or lowered inside the drying body.

[0053] This utility model embodiment does not limit the specific structure of the snap-fit ​​unit. Any structure that meets the usage requirements of this utility model is within the protection scope of this utility model.

[0054] As one embodiment, please refer to Figure 2 The snap-fit ​​unit disclosed in this embodiment of the present invention includes a first snap-fit ​​part 300 and a second snap-fit ​​part 400, and a lifting mechanical arm 500 is disposed between the first snap-fit ​​part 300 and the second snap-fit ​​part 400.

[0055] The first snap-fit ​​part 300 is provided with a first snap-fit ​​post 301, and the second snap-fit ​​part 400 is provided with a second snap-fit ​​post 401. The first snap-fit ​​post 301 and the second snap-fit ​​post 401 are respectively used to engage with the snap-fit ​​groove at the bottom of the flower basket 900. This arrangement can improve the snap-fit ​​stability between the flower basket 900 and the snap-fit ​​unit.

[0056] This utility model embodiment does not limit the specific structure of the lifting robotic arm 500. Any structure that meets the usage requirements of this utility model is within the protection scope of this utility model.

[0057] As one embodiment, the lifting robotic arm 500 disclosed in this utility model embodiment includes a first drive motor and a lifting arm body. The motor base of the first drive motor is disposed outside the drying body, and the motor shaft of the first drive motor is disposed inside the drying body and connected to the lifting arm body. The first drive motor can drive the lifting arm body to move vertically inside the drying body.

[0058] The first drive motor is started, and the motor shaft of the first drive motor extends or retracts, thereby driving the main body of the lifting arm to rise or fall, which in turn drives the clamping unit, the basket 900 loaded with wafers and the wafer support unit 700 to rise or fall.

[0059] This embodiment of the invention does not limit the specific structure of the wafer support unit 700. Any structure that meets the requirements of this invention is within the protection scope of this invention.

[0060] As one embodiment, the wafer support unit 700 disclosed in this utility model embodiment includes a top blade, a top blade rod, a lead screw, and a second drive motor. The top blade is connected to the top blade rod, the top blade rod has a cavity, and the lead screw is disposed in the cavity.

[0061] Specifically, the inner wall of the cavity is provided with a first thread, the lead screw is provided with a second thread that mates with the first thread, and the second drive motor is connected to the lead screw.

[0062] The second drive mechanism is activated, which drives the lead screw to rotate. Since the inner wall of the cavity is provided with a first thread and the lead screw is provided with a second thread that mates with the first thread, the rotational motion of the lead screw can be converted into the linear motion of the top cutter bar, that is, the top cutter bar can be raised or lowered, and then the silicon carbide wafer 1000 can be raised or lowered through the top cutter.

[0063] This utility model embodiment does not limit the specific structure of the flower basket 900. Any structure that meets the usage requirements of this utility model is within the protection scope of this utility model.

[0064] As one embodiment, please refer to Figure 6 and Figure 7 The flower basket 900 disclosed in this embodiment of the utility model is made of PFA material. The flower basket 900 includes a main frame, horizontal ribs 902 and vertical ribs 903, and there are multiple vertical ribs 903, which are arranged on the main frame 901.

[0065] Among them, there are at least two horizontal ribs 902, which are set perpendicular to the vertical ribs 903, and the distance between the horizontal ribs 902 and the top of the flower basket 900 is no more than 1 / 2 of the height of the flower basket.

[0066] It should be explained that the Chinese name for PFA is perfluoroalkoxyalkane.

[0067] The bottom of the second chamber 201 is also equipped with a drain valve 202. The drain valve 202 has a drainage speed of 0.8m / s to 2m / s. This setting can make the flower basket 900 completely dry and effectively avoid water stains remaining on the surface of the silicon carbide wafer 1000.

[0068] This embodiment of the invention does not limit the specific number of spray holes 8011 or the spray flow rate. Any quantity that meets the usage requirements of this invention is within the protection scope of this invention. Please refer to [the relevant documentation]. Figure 8 .

[0069] In a preferred embodiment, the number of injection holes 8011 disclosed in this utility model is 200-500.

[0070] As a preferred embodiment, the total jet flow rate of the jet orifice 8011 disclosed in this utility model is 20 L / min-30 L / min.

[0071] It should be noted that, please refer to Figures 2-5 The specific drying steps after cleaning the silicon carbide wafer 1000 are as follows:

[0072] 1) Open the spray cover 801, load the silicon carbide wafer 1000 after RCA cleaning into the basket 900, and transport it into the first chamber 101 of the drying body by the robotic arm. The slots on both sides of the bottom of the basket 900 are respectively engaged with the first locking post 301 of the first locking part 300 and the second locking post 401 of the second locking part 400. The first locking part 300 and the second locking part 400 are both connected to the lifting robotic arm through the knob 600.

[0073] 2) Water entered the second chamber 201;

[0074] 3) Start the lifting robotic arm 500. The lifting robotic arm 500 descends, bringing the silicon carbide wafer 1000 and the flower basket 900 down to the second chamber 201. The silicon carbide wafer 1000 is immersed. Then close the spray cover 801.

[0075] 4) The liquid inlet flow rate in the spray pipe 802 is 10L / min - 25L / min, and the pre-spray flow rate of the spray cover plate 801 is 20L / min - 30L / min, and the pre-spray time is 30S-40S;

[0076] 5) The wafer support unit 700 contacts the silicon carbide wafer 1000 at a speed of 0.8 mm / s-1 mm / s and slowly lifts the silicon carbide wafer 1000.

[0077] 6) After the silicon carbide wafer 1000 is lifted, the spraying assembly 800 is turned on, and the spraying time is 2 min - 5 min. At the same time, the drain valve 202 is turned on, and the drainage speed is 0.8 mm / s - 2 mm / s.

[0078] 7) After the water slowly drains to the bottom of the basket 900, the drain valve 202 is fully opened, the wafer support unit 700 begins to descend, the silicon carbide wafer 1000 returns to the basket 900, the spray cover 801 is opened, and the basket 900 containing the silicon carbide wafer 1000 is raised to the first chamber 101, and the drying of the silicon carbide wafer 1000 is completed.

[0079] The following is a selection process for the drying process after cleaning silicon carbide wafers (1000 series) through multiple experiments:

[0080] 1) First, the dosage and spraying method of IPA were tested, and the results were as follows:

[0081]

[0082] Verification based on the above conditions shows that the spraying component disclosed in this utility model does not require the use of hot N2, and the low IPA flow rate can significantly reduce the proportion of watermarks and improve the cleanliness of the silicon carbide wafer 1000 surface.

[0083] 2) Based on Experiment A above, further optimize the design of the flower basket 900:

[0084]

[0085] Verification based on the above conditions shows that high-top baskets can significantly reduce watermarks, but the removal effect on particle levels is poor. Choosing a low-top basket (with the horizontal ribs at the top, i.e., near the top of the basket) can significantly reduce the proportion of watermarks, ensure particle removal, and improve the surface cleanliness of silicon carbide wafer 1000.

[0086] 3) Based on experiments A and B, further optimize the slow drainage rate:

[0087]

[0088] Based on the above verification, a slow drainage speed of 0.8mm / s-2mm / s can completely dry the basket 900 and effectively avoid water stains remaining on the surface of the silicon carbide wafer 1000.

[0089] The above three experiments show that the drying device for silicon carbide wafers after cleaning disclosed in this embodiment can effectively avoid the phenomenon of local moisture residue on silicon carbide wafers due to uneven spraying, improve the consistency of drying, and thus improve the yield of silicon carbide wafer 1000 cleaning and drying.

[0090] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0091] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0092] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A drying apparatus for silicon carbide wafers after cleaning, characterized in that, It includes a drying body and a drying mechanism, wherein the drying mechanism is disposed within the drying body; The drying body includes a first drying section and a second drying section. The first drying section has a first chamber, and the second drying section has a second chamber that communicates with the first chamber. The drying mechanism includes at least a lifting assembly and a spraying assembly. The lifting assembly is used to lift and lower the basket loaded with silicon carbide wafers. The spraying assembly includes a spray cover and a spray pipe. The spray pipe is connected to the spray cover. The spray cover is placed on the top of the first chamber. The spray cover has multiple evenly distributed spray holes for spraying a mixed mist of IPA and N2 to dry the silicon carbide wafers.

2. The drying apparatus for silicon carbide wafers after cleaning according to claim 1, characterized in that, The lifting assembly includes a snap-fit ​​unit, a lifting robotic arm, and a wafer support unit. The snap-fit ​​unit is connected to the lifting robotic arm, and the wafer support unit is disposed on the lifting robotic arm.

3. The drying apparatus for silicon carbide wafers after cleaning according to claim 2, characterized in that, The latching unit includes a first latching part and a second latching part, and the lifting mechanical arm is disposed between the first latching part and the second latching part; The first snap-fit ​​part is provided with a first snap-fit ​​post, and the second snap-fit ​​part is provided with a second snap-fit ​​post. The first snap-fit ​​post and the second snap-fit ​​post are respectively used to engage with the slots on both sides of the bottom of the flower basket.

4. The drying apparatus for silicon carbide wafers after cleaning according to claim 2, characterized in that, The lifting robotic arm includes a first drive motor and a lifting arm body. The motor mount of the first drive motor is disposed outside the drying body, and the motor shaft of the first drive motor is disposed inside the drying body and connected to the lifting arm body. The first drive motor can drive the lifting arm body to move vertically inside the drying body.

5. The drying apparatus for silicon carbide wafers after cleaning according to claim 2, characterized in that, The wafer support unit includes a top blade, a top blade rod, a lead screw, and a second drive motor. The top blade is connected to the top blade rod, and a cavity is formed inside the top blade rod. The lead screw is disposed inside the cavity. The inner wall of the cavity is provided with a first thread, and the lead screw is provided with a second thread that mates with the first thread. The second drive motor is connected to the lead screw.

6. The drying apparatus for silicon carbide wafers after cleaning according to claim 5, characterized in that, The motor mount of the second drive motor is disposed outside the drying body, and the motor rod of the second drive motor is connected to the lead screw.

7. The drying apparatus for silicon carbide wafers after cleaning according to claim 1, characterized in that, The flower basket is made of PFA material; The flower basket includes a main frame, horizontal ribs and vertical ribs, and there are multiple vertical ribs, which are arranged on the main frame; There are at least two horizontal ribs, which are perpendicular to the vertical ribs. The distance between each horizontal rib and the top of the flower basket is no more than 1 / 2 of the height of the flower basket.

8. The drying apparatus for silicon carbide wafers after cleaning according to claim 1, characterized in that, A drain valve is also provided at the bottom of the second chamber, and the drain valve has a drainage speed of 0.8m / s to 2m / s.

9. The drying apparatus for silicon carbide wafers after cleaning according to claim 1, characterized in that, The number of injection holes is 200-500.

10. The drying apparatus for silicon carbide wafers after cleaning according to claim 1, characterized in that, The total jet flow rate of the jet orifice is 20 L / min-30 L / min.

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