Purification table, purification table use method, and semiconductor apparatus

Abstract

The application discloses a purification table, a purification table use method and a semiconductor device. The purification table is divided into a heat exhaust area, a cooling area and an active air intake area along a boat direction. A heat exhaust port is arranged at the top of the heat exhaust area, and an exhaust port and an exhaust fan are arranged in the cooling area. Harmful gases such as high-temperature gases and corrosive gases are exhausted through the heat exhaust port and the exhaust port, forming a structure of gradually exhausting heat and partition protection. The harmful gases such as high-temperature gases and corrosive gases which follow the quartz boat and the silicon wafer into the purification table can be quickly and effectively exhausted. Meanwhile, the temperature and concentration of the harmful gases can be greatly reduced, the silicon wafer can be prevented from being polluted, and the thermal damage and chemical damage caused by the harmful gases can be reduced. The purification table use method can adjust the rotating speed of the air supply fan and the exhaust fan of the purification table according to the air pressure value, so that the heat dissipation requirement can be met, and the silicon wafer can be prevented from being damaged due to shaking caused by too high air flow speed.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a clean bench, a method of using the clean bench, and semiconductor equipment. Background Technology

[0002] Cleanroom benches are a general term for certain components of process equipment in semiconductor manufacturing. They are used to cool and purify high-temperature products and are widely used in industries such as integrated circuits, power electronics, and solar cells.

[0003] A prior patent application with application number 202022323704.6 discloses a diffusion furnace cleanroom cooling system. By employing a combined air-cooling and water-cooling method within the cleanroom, it addresses the impact of the large amount of heat generated when silicon wafers exit the furnace, thereby accelerating the cooling rate of the silicon wafers and the cleanroom interior, improving process efficiency, and reducing the failure rate of electrical equipment. However, this diffusion furnace cleanroom cooling system still has at least the following problems:

[0004] 1. Taking solar cells as an example, in the existing production process, high-temperature gases, corrosive gases and other harmful gases in the reactor will enter the purification table along with the quartz boat and silicon wafers, making the silicon wafers contaminated and difficult to cool down.

[0005] 2. Silicon wafers can be damaged during cooling due to airflow fluctuations or excessive temperature differences.

[0006] 3. When high-temperature gases, corrosive gases, or other harmful gases come into contact with the circuit components in the electrical cabinet inside the cleanroom, they can easily cause thermal and chemical damage, increasing maintenance and usage costs.

[0007] Based on the above, there is an urgent need for a clean bench, a method for using a clean bench, and a semiconductor device to solve one of the aforementioned problems. Summary of the Invention

[0008] The first objective of this invention is to provide a purification bench that can reduce the amount of harmful gases such as high-temperature gases and corrosive gases that enter the purification bench along with the quartz boat and silicon wafers, thereby preventing further contamination of the silicon wafers or making them difficult to cool down.

[0009] The clean bench includes a frame with an inlet on its side. Along the inlet direction, the frame contains a heat dissipation zone, a cooling zone, and an active air intake zone connected in sequence.

[0010] The heat dissipation zone is equipped with a heat dissipation port, which is used to discharge harmful gases. After the process, the boat loaded with silicon wafers enters the cooling zone through the heat dissipation zone.

[0011] The cooling zone is used to place and cool the boat. The cooling zone is provided with an exhaust vent. An exhaust fan with controllable speed is installed at the exhaust vent. The exhaust fan drives the harmful gas to be discharged from the purification table through the exhaust vent.

[0012] The active air intake zone is provided with a first air inlet, and a speed-controlled blower is installed at the first air inlet.

[0013] Optionally, the purification station also includes an electrical cabinet located in the active air intake area.

[0014] Optionally, the frame has a first sidewall and a second sidewall arranged parallel to the direction of boat entry. The first sidewall is provided with a plurality of first buffer racks for placing the boat. The second sidewall is provided with a plurality of second buffer racks for placing the boat. The boat moves between the first buffer racks and the second buffer racks.

[0015] Optionally, the active air intake zone is provided with an angle-controllable air guide plate, which is used to guide the flow direction of the airflow entering the cooling zone through the air supply fan.

[0016] Optionally, temperature sensors are provided at both ends of the second buffer rack along its length, i.e., at one end of the second buffer rack near the heat dissipation area and at the other end near the active air intake area. The temperature sensors are configured such that if the temperature at the end near the active air intake area is less than 80% of the temperature at the end near the heat dissipation area, the air guide plate is controlled to guide the airflow toward the first buffer rack or between the first buffer rack and the second buffer rack.

[0017] Optionally, a third air inlet is provided along the length direction below the first sidewall, and the third air inlet is in communication with the airflow of the heat dissipation zone, the cooling zone and the active air intake zone; and / or, a second air inlet is provided along the length direction below the second sidewall, and the second air inlet is in communication with the airflow of the heat dissipation zone, the cooling zone and the active air intake zone.

[0018] Optionally, the first sidewall is provided with the exhaust vent and the exhaust fan at a position relative to the first buffer rack.

[0019] Optionally, pressure sensors are provided on both sides of the width of the first buffer rack, i.e., on the side closer to the first sidewall and on the side farther from the first sidewall. The pressure sensors are configured such that if the pressure on the side farther from the first sidewall is detected to be 0.9-1.1 standard atmospheres and the pressure on the side closer to the first sidewall is less than 80% of the pressure on the side farther from the first sidewall, the speed of the exhaust fan is reduced until the pressure on the side closer to the first sidewall is not less than 90% of the pressure on the side farther from the first sidewall, and the pressure on the side farther from the first sidewall is maintained at 0.9-1.1 standard atmospheres.

[0020] The beneficial effects of the clean bench of the present invention are as follows: by dividing the interior of the clean bench into a heat dissipation zone, a cooling zone and an active air intake zone along the direction of the quartz boat, a heat dissipation port is set at the top of the heat dissipation zone, and an exhaust port and an exhaust fan are set in the cooling zone. High-temperature gases, corrosive gases and other harmful gases are discharged through the heat dissipation port and the exhaust port, forming a structure of gradual heat dissipation and zoned protection. It can quickly and effectively discharge high-temperature gases, corrosive gases and other harmful gases that enter the clean bench with the quartz boat and silicon wafers. At the same time, it can greatly reduce the temperature and concentration of harmful gases before they come into contact with the circuit components in the electrical cabinet, prevent the silicon wafers from being contaminated and reduce the thermal and chemical damage caused by harmful gases.

[0021] The second objective of this invention is to provide a method for using a clean bench that can prevent silicon wafers from shaking or vibrating and being damaged due to airflow during cooling.

[0022] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows:

[0023] The method for using a cleanroom bench, used to control the cooling process of a boat loaded with silicon wafers after the process, includes the following steps:

[0024] S1. Place the boat on the second buffer rack inside the purification platform for slow cooling;

[0025] S2. Determine whether the boat has been slowly cooled to a preset temperature;

[0026] S3. If the boat is slowly cooled to a preset temperature, place the boat on the first buffer rack for rapid cooling.

[0027] Furthermore, while performing step S3, the following steps are also included:

[0028] S4. Obtain the air pressure value at the first buffer rack;

[0029] S5. If the air pressure at the first buffer rack is less than 0.9 standard atmospheres or greater than 1.1 standard atmospheres, adjust the speed of the exhaust fan and / or the supply fan so that the air pressure at the first buffer rack is not less than 0.9 standard atmospheres and not greater than 1.1 standard atmospheres.

[0030] The beneficial effects of the cleanroom bench usage method of the present invention are as follows: the above-mentioned cleanroom bench usage method can accelerate the cooling efficiency of silicon wafers to meet production needs, and the cooling method of slow cooling followed by rapid cooling can avoid cracks in silicon wafers due to large surface temperature differences, and also prevent damage to silicon wafers due to excessive airflow during cooling.

[0031] The third objective of this invention is to provide a semiconductor device that can reduce or avoid thermal and chemical damage to the circuit components within the purification station, thereby reducing the maintenance and operating costs of the device.

[0032] To achieve the above-mentioned technical effects, the technical solution of the present invention is as follows:

[0033] Semiconductor equipment, including the aforementioned cleanroom station.

[0034] The beneficial effects of the semiconductor device of the present invention are as follows: by setting a structure for gradual heat dissipation and zoned protection in the semiconductor device, the temperature and concentration of harmful gases can be greatly reduced before they come into contact with the circuit components inside the cabinet, thus preventing damage to the circuit components. Attached Figure Description

[0035] Figure 1 This is a first axonometric perspective view of the cleanroom bench of the present invention;

[0036] Figure 2 This is a top view of the purification table of the present invention;

[0037] Figure 3 yes Figure 2 Internal structure diagram of the AA along the middle edge;

[0038] Figure 4 This is a schematic diagram of part of the airflow direction inside the purification table of the present invention;

[0039] Figure 5 This is a schematic diagram of the structure of the clean bench with the exhaust vent plate removed according to the present invention;

[0040] Figure 6 This is a second isometric internal structure diagram of the cleanroom bench of the present invention;

[0041] Figure 7 This is a schematic diagram of the boat and silicon wafer in this invention.

[0042] In the picture:

[0043] 101. First sidewall; 102. Second sidewall; 11. Heat outlet;

[0044] 201. First buffer rack; 202. Second buffer rack; 21. Exhaust vent plate; 22. Exhaust fan; 23. Second air inlet; 24. Liquid cooling pipe; 25. Refrigeration unit; 26. Third air inlet; 27. Second filter plate;

[0045] 31. Air supply fan; 32. Electrical cabinet; 33. Filter;

[0046] 41. Boat; 42. Silicon wafer. Detailed Implementation

[0047] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Furthermore, features specified as "first" or "second" may explicitly or implicitly include one or more of those features, used to distinguish and describe features, without any order or emphasis. In the description of this invention, unless otherwise stated, "multiple" means two or more.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] The following is for reference. Figures 1 to 7This invention introduces a clean bench, its usage method, and a semiconductor device. This clean bench can be connected to reactors such as diffusion furnaces (not shown in the figure) to cool and purify high-temperature products exiting the reactor. It is widely used in industries such as integrated circuits, power electronics, and solar cell production. For ease of explanation, this invention uses cooling a quartz boat and a silicon wafer 42 as examples to illustrate the clean bench, its usage method, and the semiconductor device. Of course, this clean bench, its usage method, and the semiconductor device can also be used with other types of boats 41; this invention does not specifically limit their application.

[0052] Specifically, the clean bench includes a frame with a boat inlet on its side. The boat inlet connects to reactors such as diffusion furnaces and LPCVD furnaces. The quartz boat and silicon wafer 42, after exiting the reactor, enter the clean bench through the boat inlet along the boat inlet direction (i.e., the direction shown by arrow a in the figure). Exemplarily, in this embodiment, as... Figure 1 As shown, the direction of entry into the quartz boat is parallel to the length of the quartz boat. Of course, in some other embodiments, the direction of entry can also be perpendicular to the length of the quartz boat, meaning the quartz boat rotates after exiting the furnace and then enters the purification table. Therefore, in this invention, the relationship between the direction of entry into the quartz boat and the length of the quartz boat is not specifically limited; any direction from the inlet into the purification table is considered the direction of entry.

[0053] Inside the cleanroom, along the direction from the inlet inwards, the frame is divided into a sequentially connected heat dissipation zone, a cooling zone, and an active air intake zone. For example... Figure 2 As shown, the inlet is located in the heat dissipation zone. After the quartz boat and silicon wafer 42 enter the clean bench, they first enter the heat dissipation zone. The heat dissipation zone is equipped with a heat dissipation port 11, through which high-temperature gases, corrosive gases, and other harmful gases that follow the quartz boat and silicon wafer 42 into the clean bench can be discharged. Preferably, the heat dissipation port 11 is located at the top of the heat dissipation zone. Because of the high temperature (generally 600-700℃), harmful gases will accumulate at the top of the heat dissipation zone, thus facilitating direct discharge to the outside of the clean bench through the heat dissipation port 11 located at the top. This significantly reduces the concentration of harmful gases inside the clean bench and prevents harmful gases from damaging the circuit components in the electrical cabinet 32 ​​inside the clean bench.

[0054] Continue to refer to Figure 2 , Figure 3 and Figure 5As shown, the quartz boat passes through the heat dissipation zone and enters the cooling zone. The cooling zone is equipped with a buffer rack, allowing the quartz boat and silicon wafer 42 to remain in the cooling zone for cooling. The cooling zone has an exhaust vent, at which a speed-controlled exhaust fan 22 is installed. The exhaust fan 22 can expel harmful gases from inside the purification table through the exhaust vent and reduce the temperature of the purification table. Preferably, an exhaust perforated plate 21 is provided on the upper part of the side wall of the purification table. The exhaust perforated plate 21 has several exhaust holes to form the aforementioned exhaust vent, which can significantly increase the exhaust area and effectively expel high-temperature gases by utilizing the effect of gas heating and rising. Optionally, a cooling device 25, such as a liquid cooling plate, is installed on the top of the cooling zone to reduce the temperature inside the purification table.

[0055] The active air intake zone is located at the end of the air purification unit, such as... Figure 2 , Figure 3 As shown, the active air intake zone is equipped with a first air inlet, at which a speed-controlled blower 31 is installed. The blower 31 can deliver cold air from outside the purification table into the purification table, where the cold air absorbs heat from the quartz boat and silicon wafer 42. Preferably, a filter 33 is also provided at the first air inlet, so that the air entering the purification table through the first air inlet has a high degree of cleanliness.

[0056] refer to Figure 4 , Figure 5 As shown, the interior of the purification bench is divided into a heat dissipation zone, a cooling zone, and an active air intake zone along the direction of the quartz boat. A heat dissipation port 11 is set at the top of the heat dissipation zone, and an exhaust port and an exhaust fan 22 are set in the cooling zone. High-temperature gases, corrosive gases, and other harmful gases are quickly discharged through the heat dissipation port 11 and the exhaust port, forming a structure of gradual heat dissipation and zoned protection. This structure can quickly and effectively discharge high-temperature gases, corrosive gases, and other harmful gases that enter the purification bench along with the quartz boat and silicon wafer 42. At the same time, it can greatly reduce the temperature and concentration of harmful gases, prevent the silicon wafer 42 from being contaminated, and reduce the thermal and chemical damage caused by harmful gases.

[0057] Optionally, in this embodiment, the electrical cabinet 32 ​​of the cleanroom is placed within the active air intake zone. Therefore, by controlling the air supply fan 31, the airflow within the active air intake zone can flow from the active air intake zone to the cooling zone, further reducing or preventing the diffusion and flow of harmful gases from the cooling zone to the active air intake zone, thus avoiding thermal and chemical damage to the circuit components in the electrical cabinet 32. Of course, in some other embodiments, the electrical cabinet 32 ​​can be adapted to be installed in other areas within the cleanroom, depending on its actual tolerable operating temperature. Since the active air intake zone is equipped with a first air inlet, and the first air inlet is equipped with a speed-controlled air supply fan 31, the airflow within the active air intake zone is adjusted by controlling the speed of the air supply fan 31 to deliver air into the cleanroom, causing the airflow within the active air intake zone to flow from the active air intake zone to the cooling zone. This further reduces or prevents the diffusion and flow of harmful gases from the cooling zone to the active air intake zone, providing better protection for the circuit components in the electrical cabinet 32 ​​(some airflow directions can be referenced). Figure 4 (Airflow arrow in the image).

[0058] Optionally, the clean bench is equipped with several buffer racks to support the quartz boat and the product or product carrier awaiting cooling. For ease of explanation, in this invention, the two side walls on the frame parallel to the boat entry direction are defined as the first side wall 101 and the second side wall 102, respectively. The buffer racks are installed on the first side wall 101 and the second side wall 102 to support the quartz boat to be cooled and the silicon wafers 42 inside the quartz boat.

[0059] like Figure 6 As shown, in this embodiment, the buffer rack is divided into a first buffer rack 201 and a second buffer rack 202. Several second buffer racks 202 are disposed inside the second side wall 102 for placing freshly baked quartz boats and silicon wafers 42. Several first buffer racks 201 are disposed inside the first side wall 101 for placing quartz boats and silicon wafers 42 transferred from the second buffer racks 102. Several exhaust vents are provided on the first side wall 101. The exhaust fan 22 accelerates the airflow near the exhaust vents, allowing the cold air flowing from the active air intake area to the first buffer rack 201 to fully contact the quartz boats and silicon wafers 42 and mix thoroughly with the warmer air before being discharged from the purification table. This allows the quartz boats and silicon wafers 42 on the first buffer rack 201 to dissipate heat quickly, preventing the warmer air from accumulating in the purification table or even spreading to the active air intake area and affecting the electrical cabinet 32.

[0060] Continue to refer to Figure 6 As shown, a second air inlet 23 is provided along the length of the second sidewall 102. The second air inlet 23 is located below the second buffer rack 202. Cooler air from outside the purification table enters through the second air inlet 23 to dissipate heat from the quartz boat and silicon wafer 42 on the second buffer rack 202, thereby improving the cooling efficiency of the purification table. Preferably, in this embodiment, as... Figure 5 As shown, the exhaust fan 22 is located at the first side wall 101 to prevent it from affecting the airflow stability at the second buffer rack 202, which could lead to large temperature differences or sudden temperature changes on the surface of the high-temperature silicon wafer 42 located in the second buffer rack 202, making it prone to cracking. (Reference) Figure 3 As shown, at least some exhaust vents and at least some exhaust fans 22 are disposed on the first side wall 101 and correspond to the position of the first buffer rack 201, which can further optimize the cooling efficiency of the first buffer rack 201. Optionally, the first side wall 101 is also provided with liquid cooling pipes 24, which can reduce the temperature inside the clean bench and prevent the operating temperature of the exhaust fans 22 from becoming too high, thus protecting the exhaust fans 22.

[0061] Of course, it is understandable that the cooler air entering the purification station from the active air intake zone will also enter the cooling zone. Therefore, in this embodiment, an adjustable air guide plate (not shown in the figure) can also be set in the active air intake zone to guide the flow direction and speed of the cold air when it enters the cooling zone, so as to control the cooling speed of the silicon wafer 42 on the first buffer rack 201 or the second buffer rack 202.

[0062] Specifically, temperature sensors are installed at both ends of the second buffer rack 202 along its length, namely, at one end near the heat sink area and the other end near the active air intake area. When the temperature sensor detects that the temperature at the end near the active air intake area is less than 80% of the temperature at the end near the heat sink area, a large temperature difference exists on the surface of the silicon wafer 42 on the second buffer rack 202, which can easily lead to cracks. In this case, the air guide plate is controlled to direct the airflow towards the first buffer rack 201 or between the first buffer rack 201 and the second buffer rack 202, thereby reducing the amount of cold air flowing to the second buffer rack 202 and preventing a large temperature difference on the surface of the silicon wafer 42 on the second buffer rack 202. Optionally, the plane of the silicon wafer 42 is parallel to the inlet direction, allowing the airflow to flow along the length of the second buffer rack 202. The hot airflow fills the spaces between the silicon wafers 42, reducing the direct mixing of hot and cold airflows between the silicon wafers 42 and preventing a large temperature difference on the surface of the silicon wafer 42.

[0063] Optionally, refer to Figure 7 As shown, in some embodiments, the plane of silicon wafer 42 is parallel to the infeed direction or perpendicular to the infeed direction, so that the exhaust fan 22 can cause the airflow to flow along the short direction (i.e. the width direction) of the first buffer rack 201 to quickly dissipate heat with the shortest path, that is, after the airflow contacts the surface of silicon wafer 42, it flows out of the first buffer rack 201 with the shortest path.

[0064] Optionally, refer to Figure 7As shown, in some parallel embodiments, in order to facilitate the inflow of cold air into the first buffer rack 201, the plane direction of the silicon wafer 42 is parallel to the above-mentioned inlet direction, so that the gaps between the stacked silicon wafers 42 face the active air inlet area, which facilitates the inflow of cold air.

[0065] Optionally, in order to determine whether the silicon wafer 42 is shaking, a pressure sensor (not shown in the figure) is installed in the first buffer rack 201, and the speed of the exhaust fan 22 and the supply fan 31 is adjusted according to the detected pressure value to ensure that the pressure at the first buffer rack 201 is stable (i.e. there is no high-speed airflow or turbulent airflow).

[0066] Specifically, air pressure sensors are installed on both sides of the first buffer rack 201 in the width direction, namely the side closer to the first sidewall 101 and the side farther from the first sidewall 101. If the air pressure detected on the side farther from the first sidewall 101 is 0.9-1.1 standard atmospheres, and the air pressure on the side closer to the first sidewall 101 is less than 80% of the air pressure on the side farther from the first sidewall 101, then the speed of the adjacent or all exhaust fans 22 is reduced until the air pressure on the side closer to the first sidewall 101 is not less than 90% of the air pressure on the side farther from the first sidewall 101, and the air pressure on the side farther from the first sidewall 101 is maintained at 0.9-1.1 standard atmospheres.

[0067] It should be noted that because of its proximity to the exhaust fan 22, the air pressure on the side near the first sidewall 101 will be relatively low, remaining in a continuous negative pressure state. The side furthest from the first sidewall 101, where airflow enters the silicon wafer 42, may be below 1 atmosphere, but should normally be between 0.9 and 1.1 atmospheres. If the pressure difference is too large, it will generate high-speed airflow, causing the silicon wafer 42 to vibrate. If the air pressure on both sides is greater than 1.1 atmospheres, it indicates that heat has accumulated inside the cleanroom, preventing normal cooling.

[0068] Preferably, multiple sets of pressure sensors are equidistantly arranged along the length of the first buffer rack 201. Each set of sensors includes two pressure sensors, which are symmetrically arranged about the central axis of the first buffer rack 201 along its length. Multiple sets of symmetrically arranged pressure sensors can measure pressure more accurately and avoid the influence of temperature on the measurement results.

[0069] Alternatively, transparent glass can be installed in the side wall of the rack, allowing operators to directly observe the cooling of the silicon wafer 42. For example, transparent glass is installed on the first side wall 101, and several heat dissipation holes are provided on the transparent glass, forming the aforementioned exhaust vents. Optionally, transparent glass is also installed on the second side wall 102, and similarly, several heat dissipation holes are provided, which can further optimize heat dissipation.

[0070] Optionally, in this embodiment, reference is made to Figure 6 As shown, the second air inlet 23 is a through-slot, the length of which is the same as the length of the quartz boat, allowing cooler air to flow evenly through the quartz boat and preventing poor heat dissipation in parts or sections of the silicon wafers 42. Preferably, a first filter plate (not shown in the figure) is provided at the second air inlet 23, and the first filter plate contains filter cotton to filter the air entering the purification table from the second air inlet 23.

[0071] Furthermore, such as Figure 4 As shown, a third air inlet 26 is provided on the first side wall 101. The third air inlet 26 is located below the first buffer rack 201. Similar to the second air inlet 23, cooler air from outside the purification table automatically enters through the third air inlet 26, flows through the first buffer rack 201, and absorbs heat. It should be noted that the cooler air entering through the second air inlet 23 and the third air inlet 26 is passively introduced (as opposed to being supplied by a fan), and its airflow is related to the air pressure difference inside and outside the purification table. Therefore, by adjusting the speed of the exhaust fan 22 and the supply fan 31, the air pressure inside the purification table can be controlled, thereby affecting the passive airflow. Of course, a second filter plate 27 can also be installed in the third air inlet 26 to filter the air entering the purification table from the third air inlet 26.

[0072] The present invention also provides a method for using a clean bench, which can control the clean bench to cool the boat 41 (including the silicon wafer 42 inside the boat 41) to be cooled, and the specific steps include:

[0073] S1. Place boat 41 on the second buffer rack 202 inside the purification platform for slow cooling.

[0074] Among them, reference Figure 6 As shown, the quartz boat and the silicon wafer 42 inside the quartz boat are slowly cooled at the second buffer rack 202 under high temperature conditions to prevent excessive temperature differences from causing cracks in the silicon wafer 42. Preferably, a temperature sensor is provided to detect the temperature difference in the area of ​​the second buffer rack 202 to prevent excessive temperature differences on the surface of the silicon wafer 42.

[0075] S2. Determine whether boat 41 has been slowly cooled to the preset temperature.

[0076] Various non-contact measurement methods, such as infrared measurement and ambient temperature measurement, can be used, or contact measurement can be performed by setting a temperature sensor (not shown in the figure). This invention does not make specific limitations on this, as long as the temperature of the quartz boat and silicon wafer 42 can be measured.

[0077] S3. If boat 41 is slowly cooled to the preset temperature, place boat 41 on the first buffer rack 201 for rapid cooling.

[0078] Several exhaust vents are located next to at least part of the first buffer rack 201, and exhaust fans 22 are installed outside the exhaust vents, driving the gas inside the clean bench to be discharged quickly. Due to the high-speed airflow near the exhaust vents, the airflow generates turbulence, allowing the cooler air entering the clean bench from the second air inlet 23 and from the active air intake zone to fully contact the high-temperature objects and quickly carry the heat out of the clean bench. This allows the quartz boat and the silicon wafer 42 inside the quartz boat to cool down quickly, and prevents heat accumulation inside the clean bench.

[0079] Of course, at this time the second buffer rack 202 is in an empty state and can be used to place the quartz boat and silicon wafer 42 of the next batch, so that the clean bench can cool the quartz boat and silicon wafer 42 of two batches at the same time, thereby improving the cooling efficiency of the clean bench.

[0080] Furthermore, the S3 process also includes the following steps:

[0081] S4. Obtain the air pressure value at the first buffer rack 201.

[0082] The air pressure value can be detected by setting up the aforementioned air pressure sensor. The air pressure sensor can be set on the first buffer rack 201 or near the first buffer rack 201. As long as the air pressure value can be obtained, it falls within the scope of protection of this invention.

[0083] S5. If the air pressure at the first buffer rack 201 is less than 0.9 standard atmospheres or greater than 1.1 standard atmospheres, adjust the speed of the exhaust fan 22 and / or the supply fan 31 so that the air pressure at the first buffer rack 201 is not less than 0.9 standard atmospheres and not greater than 1.1 standard atmospheres.

[0084] For example, when the air pressure is less than 0.9 atmospheres, the speed of the exhaust fan 22 is reduced, or the speeds of both the supply fan 31 and the exhaust fan 22 are reduced simultaneously to decrease the airflow velocity within the purification unit. When the air pressure is greater than 1.1 atmospheres, the speed of the exhaust fan 22 is increased, or the speed of the supply fan 31 is increased, or both the exhaust fan 22 and the supply fan 31 are increased simultaneously to quickly remove accumulated heat.

[0085] By using the above-mentioned clean bench method, the cooling efficiency of silicon wafer 42 can be accelerated to meet production needs. The cooling method of slow cooling followed by fast cooling can prevent the silicon wafer 42 from cracking due to large surface temperature differences. It also prevents the silicon wafer 42 from shaking and being damaged due to excessive airflow during cooling.

[0086] Optionally, in some embodiments, the active air intake zone is provided with an angle-adjustable air guide plate, and the temperature difference at the second buffer rack 202 can also be controlled using the following step S6:

[0087] S6. If the temperature difference at the second buffer rack 202 is large, the air guide plate is controlled to guide the airflow to blow towards the first buffer rack 201 or between the first buffer rack 201 and the second buffer rack 202.

[0088] By adjusting the angle of the air guide plate, the amount of cold air flowing directly to the second buffer rack 202 can be reduced, thus preventing the high-temperature silicon wafer 42 placed on the second buffer rack 202 from cracking due to excessive temperature difference and uneven cooling.

[0089] The present invention also provides a semiconductor device, including the aforementioned cleanroom bench. By incorporating a structure for gradual heat dissipation and zoned protection within the semiconductor device, the temperature and concentration of harmful gases can be significantly reduced before they come into contact with the circuit components inside the electrical cabinet 32, thus providing excellent protection for the circuit components within the electrical cabinet 32.

[0090] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A clean bench, characterized in that, The unit includes a frame with a boat inlet on its side. Along the boat inlet direction, the frame contains a heat dissipation zone, a cooling zone, and an active air intake zone connected in sequence, wherein: The heat dissipation zone is provided with a heat dissipation port (11), which is used to discharge harmful gases. After the process, the boat (41) loaded with silicon wafers (42) enters the cooling zone through the heat dissipation zone. The cooling zone is used to place and cool the boat (41). The cooling zone is provided with an exhaust vent. An exhaust fan (22) with controllable speed is installed at the exhaust vent. The exhaust fan (22) drives the harmful gas to be discharged from the purification table through the exhaust vent. The active air intake zone is provided with a first air inlet, and a speed-controllable blower (31) is installed at the first air inlet. The frame has a first sidewall (101) and a second sidewall (102) arranged parallel to the direction of boat entry. The first sidewall (101) is provided with a plurality of first buffer racks (201), which are used to place the boat (41). The second sidewall (102) is provided with a plurality of second buffer racks (202), which are used to place the boat (41). The boat (41) moves between the first buffer rack (201) and the second buffer rack (202).

2. The cleanroom bench according to claim 1, characterized in that, The purification station also includes an electrical cabinet (32), which is located in the active air intake area.

3. The cleanroom bench according to claim 1, characterized in that, The active air intake zone is equipped with an angle-controllable air guide plate, which is used to guide the airflow direction of the airflow entering the cooling zone through the air supply fan (31).

4. The cleanroom bench according to claim 3, characterized in that, Temperature sensors are provided at both ends of the second buffer rack (202) along its length, that is, at one end of the second buffer rack (202) near the heat dissipation area and at the other end near the active air intake area. The temperature sensor is configured to: if the temperature at the end near the active air intake zone is less than 80% of the temperature at the end near the heat dissipation zone, control the air guide plate to direct the airflow toward the first buffer rack (201) or between the first buffer rack (201) and the second buffer rack (202).

5. The cleanroom bench according to claim 1, characterized in that, A third air inlet (26) is provided along the length direction below the first sidewall (101), and the third air inlet (26) is in communication with the airflow of the heat dissipation zone, the cooling zone and the active air intake zone; And / or, a second air inlet (23) is provided along the length direction below the second sidewall (102), and the second air inlet (23) is in communication with the airflow of the heat dissipation zone, the cooling zone and the active air intake zone.

6. The cleanroom bench according to claim 1, characterized in that, The first sidewall (101) is provided with the exhaust port and the exhaust fan (22) at a position relative to the first buffer rack (201).

7. The cleanroom bench according to claim 1, characterized in that, Pressure sensors are provided on both sides of the width direction of the first buffer rack (201), namely on the side closer to the first sidewall (101) and the other side away from the first sidewall (101). The air pressure sensor is configured to: if the air pressure on the side away from the first sidewall (101) is detected to be 0.9-1.1 standard atmospheres, and the air pressure on the side near the first sidewall (101) is less than 80% of the air pressure on the side away from the first sidewall (101), then reduce the speed of the exhaust fan (22) until the air pressure on the side near the first sidewall (101) is not less than 90% of the air pressure on the side away from the first sidewall (101), and maintain the air pressure on the side away from the first sidewall (101) at 0.9-1.1 standard atmospheres.

8. A method for using a cleanroom bench, used to control the cleanroom bench as described in any one of claims 1-7 to cool a boat (41) loaded with silicon wafers (42) after the process, characterized in that, Includes the following steps: S1. Place the boat (41) on the second buffer rack (202) inside the purification platform for slow cooling; S2. Determine whether the boat (41) has been slowly cooled to a preset temperature; S3. If the boat (41) is slowly cooled to a preset temperature, place the boat (41) on the first buffer rack (201) for rapid cooling. Furthermore, while performing step S3, the following steps are also included: S4. Obtain the air pressure value at the first buffer rack (201); S5. If the air pressure at the first buffer rack (201) is less than 0.9 standard atmospheres or greater than 1.1 standard atmospheres, adjust the speed of the exhaust fan (22) and / or the supply fan (31) so that the air pressure at the first buffer rack (201) is not less than 0.9 standard atmospheres and not greater than 1.1 standard atmospheres.

9. A semiconductor device, characterized in that, The cleanroom unit includes any one of claims 1-7.

Images