Chip manufacturing phosphorus diffusion control device

Abstract

The application discloses a chip manufacturing phosphorus diffusion control device, which comprises a source temperature cold well, a plurality of semiconductor cold sources and an isothermal air duct module, the source temperature cold well comprises a cold well cylinder body and an upper pressing cover, the cold well cylinder body is provided with a plurality of cold source mounting seats from top to bottom, the semiconductor cold source comprises a rotary support arranged on the cold source mounting seat, an isothermal mounting cylinder used for coaxial rotation with the cold well cylinder body, a plurality of semiconductor refrigerating sheets arranged around the isothermal mounting cylinder and a control power source, the isothermal air duct module comprises a flow guide air ring coaxially connected with the isothermal mounting cylinder and located in the cold well cylinder body and a suspension frame used for bearing a liquid source bottle, the peripheral surface and the bottom of the suspension frame are provided with a plurality of hollow structures, and the peripheral side and the bottom of the liquid source bottle are separated from the cold well cylinder body to form the isothermal air duct, and the flow guide air ring surrounds the suspension frame and is used for making the upper and lower layers of air flow by rotation, and the device has the advantages of small volume and constant temperature control without complex operation compared with the prior art.

Description

Technical Field

[0001] This invention relates to the field of temperature control device technology, specifically to a phosphorus diffusion control device for chip manufacturing. Background Technology

[0002] Phosphorus diffusion is a crucial step in chip manufacturing. Typically, the fabrication of a PN junction in semiconductors involves creating a P-type region and an N-type region within a single semiconductor crystal, achieving contact between the P-type and N-type semiconductors within the crystal. Currently, this is primarily done by preparing a tunneling oxide passivation layer in an LPCVD machine and then directly transferring the silicon wafer to a high-temperature diffusion furnace for phosphorus or boron doping. The purpose of phosphorus diffusion is to alter the electronic properties of the semiconductor material, typically used to create N-type semiconductor regions (phosphorus-rich regions). N-type regions have excess free electrons, which improve electrical conductivity. This is essential for manufacturing electronic components such as PN junctions, transistors, and capacitors. During phosphorus diffusion, a specific phosphorus source material (such as phosphorus compound gas) is typically used. The chip is placed in a high-temperature environment, and phosphorus atoms are introduced into the semiconductor material through diffusion. The high temperature allows phosphorus atoms to diffuse rapidly and integrate into the crystal structure, thereby altering the material's electrical conductivity.

[0003] Currently, phosphorus oxychloride is commonly used as the phosphorus source for diffusion. Phosphorus oxychloride is in liquid form, colorless and transparent, easily hydrolyzed, and highly volatile. Its diffusion principle involves decomposition at high temperatures to form phosphorus pentachloride and phosphorus oxide, which then react with silicon to form silicon dioxide and phosphorus atoms. The liquid phosphorus source diffusion method offers advantages such as high-efficiency production and uniform, flat PN junctions, which is crucial for manufacturing large-area solar cells. However, there are several issues to consider: precise and reasonable temperature control of the phosphorus source is essential. The phosphorus source requires constant temperature, and its accuracy is critical to the quality of the chip. Since the ambient temperature around the diffusion furnace typically reaches around 35°C, the phosphorus source temperature needs to be within 20±1°C. Therefore, a source temperature controller with high temperature accuracy is needed to house the liquid source bottle and ensure a constant temperature of the phosphorus source entering the diffusion furnace.

[0004] Current temperature control devices involve adding a certain amount of water to a temperature-controlled chamber for cooling. However, water cooling requires constant monitoring of the liquid level to prevent it from becoming too high or too low. Water should be added or removed when changing the source bottle. The water also needs to be changed periodically depending on its quality. To address this, the inventors propose a method using a semiconductor refrigeration chip to construct a source temperature cooling well, thereby achieving temperature control and solving the problem of phosphorus source temperature control in phosphorus diffusion. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned technical defects and provide a chip manufacturing phosphorus diffusion control device that can realize intelligent and visual energy saving.

[0006] This design proposes a phosphorus diffusion control device for chip manufacturing, including a source temperature cold well, several semiconductor cold sources, and a temperature equalization duct module. This device controls the temperature of liquid phosphorus sources using a vertical cooling and placement configuration. The source temperature cold well includes a vertical cold well cylinder and an upper pressure cap on top of the cylinder. Several cold source mounting seats are arranged from top to bottom on the cold well cylinder, and each mounting seat contains a semiconductor cold source. Multiple heat dissipation windows are provided on the outer side of each mounting seat. The semiconductor cold source includes a slewing bearing mounted on the mounting seat, a temperature equalization mounting cylinder located at the rotating end of the slewing bearing and coaxially rotating with the cold well cylinder, and a surrounding... The system includes several thermoelectric cooling chips placed around the temperature equalization mounting cylinder and a control power source for driving the rotation of the slewing bearing. Each thermoelectric cooling chip has fins extending into the cold well cylinder. The temperature equalization duct module includes a guide air ring coaxially connected to the temperature equalization mounting cylinder and located inside the cold well cylinder, as well as a suspension frame for carrying the liquid source bottle. The suspension frame has multiple perforations on its periphery and bottom, and the suspension frame is isolated from the inner wall of the cold well cylinder, and the bottom of the suspension frame is isolated from the bottom surface of the cold well cylinder, thus separating the periphery and bottom of the liquid source bottle from the cold well cylinder to create a temperature equalization duct. The guide air ring surrounds the suspension frame and is used to generate airflow between the upper and lower layers by rotation.

[0007] Furthermore, multiple connecting plates are installed from top to bottom inside the cold well cylinder. The connecting plates are fixed with vertical slides, and the suspension frame is slidably connected to the vertical slides, which facilitates the removal and positioning of the liquid source bottle.

[0008] Furthermore, the cold well shell is composed of several independent shells, which are connected as a whole by connecting the cold source mounting base on the upper or lower side.

[0009] Furthermore, the control power source includes a gear ring coaxially and fixedly mounted on the rotating end of the slewing bearing, a drive motor fixedly mounted on the cold source mounting base, and a transmission gear mounted on the drive motor and used to mesh with the gear ring.

[0010] Furthermore, in this embodiment, a parallel connection is adopted. In the parallel connection, multiple thermoelectric coolers are connected together in parallel. The positive and negative terminals of several thermoelectric coolers of the same thermoelectric cold source are respectively connected to an annular conductor fixedly installed on the outer periphery of the uniform temperature mounting cylinder. The annular conductor is electrically connected to the electrical control box through a sliding contact line.

[0011] Furthermore, the airflow guide ring includes several guide vanes evenly distributed circumferentially on the temperature equalization mounting cylinder.

[0012] Furthermore, several temperature probes are installed on the inner sidewall of the cold well casing.

[0013] Furthermore, a heating element is provided in the temperature equalization channel at the bottom of the cold well body, and an exhaust vent is provided around the heating element in the cold well body.

[0014] Furthermore, the upper pressure cap is detachably mounted from the cold well cylinder, and it is equipped with a latch for engaging with the suspension frame. The upper pressure cap has a central hollow section, allowing the liquid source bottle to be connected to the gas passage.

[0015] Furthermore, the top of the cold well casing is equipped with a locking mechanism for locking the upper pressure cap. The locking mechanism includes a retaining ring located at the top of the cold well casing, a pair of symmetrically arranged adjusting screws, and four locking screws. The inner side of the retaining ring has a toothed locking groove, while the upper pressure cap has a matching locking protrusion. The adjusting screw is a double-ended stud, with two locking screws screwed to each end. The two locking screws on the same adjusting screw are hinged to the cold well casing and the retaining ring through a fisheye bearing and a hinge seat.

[0016] After adopting the above solution, the advantages of this invention compared with the prior art are:

[0017] 1. This solution uses a semiconductor cooling chip for cooling. Compared with traditional water cooling, it has a faster temperature regulation response and more accurate temperature control. At the same time, it does not require cumbersome cooling water replacement steps, making it simpler and more convenient to use.

[0018] 2. By using a well-shaped cooling shell in conjunction with a designed temperature-equalizing air duct module, the temperature uniformity of the internal air can be further improved and the airflow speed can be manually controlled, thereby further improving the accuracy of temperature control and enabling automated constant temperature control. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0020] Figure 2 This is a top view schematic diagram of a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0021] Figure 3 This invention relates to a phosphorus diffusion control device for chip manufacturing. Figure 2 A schematic diagram of the AA section.

[0022] Figure 4 This is a three-dimensional schematic diagram of a cold source mounting base for a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0023] Figure 5 This is a schematic diagram of the cold well cylinder and suspension frame structure of a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0024] Figure 6 This is a three-dimensional schematic diagram of the semiconductor cold source of a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0025] Figure 7 This is a schematic diagram of the connection between the upper pressure cover and the locking mechanism of a phosphorus diffusion control device for chip manufacturing according to the present invention.

[0026] As shown in the figure: 1. Source temperature cold well, 2. Semiconductor cold source, 3. Temperature equalization duct module, 4. Cold well cylinder, 5. Upper pressure cover, 6. Cold source mounting base, 7. Slewing bearing, 8. Temperature equalization mounting cylinder, 9. Semiconductor cooling chip, 10. Control power source, 11. Fin, 12. Air guide ring, 13. Suspension bracket, 14. Connecting plate, 15. Vertical slide rail, 16. Gear ring, 17. Drive motor, 18. Transmission gear, 19. Annular conductor, 20. Sliding contact line, 21. Air guide vane, 22. Temperature probe, 23. Heating element, 24. Exhaust ventilation hole, 25. Locking tenon, 26. Locking ring, 27. Adjusting screw, 28. Locking screw, 29. Locking groove, 30. Locking protrusion. Detailed Implementation

[0027] The following description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Example 1, see Figure 1-7 As shown:

[0029] This embodiment proposes a phosphorus diffusion control device for chip manufacturing, including a source temperature cold well 1, two semiconductor cold sources 2, and a uniform temperature air duct module 3.

[0030] Since this device controls the temperature of a liquid phosphorus source, it employs a vertical shaft cooling and placement configuration. Figure 1 and Figure 4 The source temperature cold well 1 includes a vertical cold well cylinder 4 and an upper pressure cover 5 disposed on the top of the cold well cylinder 4. The cold well cylinder 4 is provided with two cold source mounting seats 6 from top to bottom, and each cold source mounting seat 6 is provided with a semiconductor cold source 2.

[0031] The cold well body 4 consists of three independent bodies, each of which is connected as a whole by a cold source mounting base 6 on the upper or lower side. The cold source mounting base 6 is a double-layered annular base. As can be seen from the attached figure, the outer side of the cold source mounting base 6 has multiple heat dissipation windows, and the annular hollow inside the cold well body 4 facilitates the installation of the semiconductor cold source 2.

[0032] Multiple connecting plates 14 are arranged from top to bottom inside the cold well body 4. The connecting plates 14 are used to fix and install the vertical slide rail 15. In this design, the vertical slide rail 15 is a vertically arranged slide rail, which facilitates the removal and positioning of the liquid source bottle. At the same time, several temperature probes 22 can be installed on the connecting plates 14 of the cold well body 4 for temperature measurement.

[0033] The semiconductor cold source 2 includes a slewing bearing 7 mounted on a cold source mounting base 6, a temperature equalization mounting cylinder 8 mounted on the rotating end of the slewing bearing 7 and used for coaxial rotation with the cold well cylinder 4, a plurality of semiconductor cooling chips 9 surrounding the temperature equalization mounting cylinder, and a control power source 10 for driving the rotating end of the slewing bearing 7 to rotate. (See attached diagram) Figure 3 , 6 The slewing bearing 7 has a fixed end and a rotating end. The fixed end is mounted on the cold source mounting base 6, and the rotating end is connected to the temperature equalization mounting cylinder 8, which allows the temperature equalization mounting cylinder 8 to be positioned between the two independent cylinders of the cold well cylinder 4. Multiple windows are opened on the periphery of the temperature equalization mounting cylinder 8 to fix the fins 11. The free ends of the fins 11 extend into the cold well cylinder 4, while the outer ends are in contact with the cooling surface of the semiconductor refrigeration chip 9.

[0034] By making the thermoelectric cooler 9 rotatable, temperature deviations within the cooling well cylinder 4 caused by the position and individual differences of the thermoelectric cooler 9 can be uniformly distributed. Simultaneously, it can assist in heat dissipation from the outer surface of the thermoelectric cooler 9, thereby stabilizing the cooling capacity. In this embodiment, the control power source 10 includes a gear ring 16 coaxially and fixedly mounted on the rotating end of the slewing bearing 7, a drive motor 17 fixedly mounted on the cold source mounting base 6, and a transmission gear 18 mounted on the drive motor 17 and used to mesh with the gear ring 16.

[0035] Since the thermoelectric cooler 9 is rotating, the positive and negative terminals of several thermoelectric coolers 9 from the same thermoelectric cold source 2 are respectively connected to an annular conductor 19 fixedly installed on the outer periphery of the temperature equalization mounting cylinder 8. The annular conductor 19 is electrically connected to the electrical control box through a sliding contact line 20. In this embodiment, a parallel connection is adopted. In the parallel connection, multiple thermoelectric coolers 9 are connected together in parallel, and the current is split among the individual coolers. This connection method can increase the current capacity of the system and improve the overall cooling power. The parallel connection can reduce the total resistance of the system, improve efficiency, and make it easier to achieve a uniform temperature distribution.

[0036] The temperature equalization duct module 3 includes a guide air ring 12 coaxially connected to the temperature equalization mounting cylinder 8 and located within the cold well cylinder 4, and a suspension bracket 13 for supporting the liquid source bottle. (See appendix for details.) Figure 4 , 5 As shown, the suspension frame 13 is a hexagonal cylinder. Figure 2 , Figure 3As can be seen, it can stably prevent the source bottle from being moved. Meanwhile, the top of the suspension frame 13 has a handle that slides smoothly with the vertical slide rail 15, allowing for smooth pulling. Multiple perforations are provided on the periphery and bottom of the suspension frame 13. The suspension frame 13 is isolated from the inner wall of the cold well cylinder 4, and the bottom of the suspension frame 13 is isolated from the bottom surface of the cold well cylinder 4. This separates the periphery and bottom of the liquid source bottle from the cold well cylinder 4, creating a uniform temperature airflow channel. The airflow guide ring 12 surrounds the suspension frame 13 and is used to generate airflow between the upper and lower layers through rotation.

[0037] The airflow guide ring 12 includes several circumferentially distributed guide vanes 21 on the temperature equalization mounting cylinder 8. These vanes 21 surround the suspension frame 13 and can form vortices, thus guiding the airflow. The temperature equalization duct can be considered as a cylindrical guide area surrounding the entire suspension frame 13 and a convection area at the bottom of the suspension frame 13. Typically, the first semiconductor cold source 2 is located in the upper half of the source bottle, where there is no liquid phosphorus source, thus serving as the primary air cooling source. The secondary semiconductor cold source 2 is mainly located near the liquid phosphorus source and can be set close to the target temperature. After the airflow undergoes primary and secondary cooling, it can convect and mix at the bottom of the suspension frame 13, stabilizing the temperature at the bottom of the source bottle.

[0038] In some cases, a heating element 23 can be installed in the temperature equalization channel at the bottom of the cold well cylinder 4 to prevent the source bottle from becoming too cold and difficult to recover, and an exhaust vent 24 is provided around the heating element 23 in the cold well cylinder 4. That is, the gas flow and exhaust speed can be controlled by the rotation speed.

[0039] In this embodiment, the upper pressure cover 5 is detachably connected to the cold well cylinder 4, and is provided with a latch 25 for abutting against the suspension frame 13. (See attached diagram) Figure 7 The bottom surface of the upper pressure cap 5 has a protruding latch 25 that engages with the handle of the suspension bracket 13, and the center of the upper pressure cap 5 is hollowed out to allow the liquid source bottle to enter the gas passage. In this design, the top of the cold well body 4 is provided with a locking mechanism for locking the upper pressure cap 5. The locking mechanism is used to enhance the installation stability of the upper pressure cap 5. Specifically, the locking mechanism includes a retaining ring 26 located on the top of the cold well body 4, a pair of symmetrically arranged adjusting screws 27, and four locking screws 28. It can be seen that the inner side of the retaining ring 26 is provided with a toothed locking groove 29, and the upper pressure cap 5 is provided with a matching locking protrusion 30. The adjusting screw 27 is a double-ended stud, with two locking screws 28 screwed to each end. The two locking screws 28 on the same adjusting screw 27 are hinged to the cold well body 4 and the retaining ring 26 through a fisheye bearing and a hinge seat. In this way, the upper pressure cover 5 is fixedly engaged with the suspension frame 13, and the upper pressure cover 5 can be fixed with the cold well cylinder 4 by means of the suspension adjusting screw 27.

[0040] In this solution, a thermoelectric cooler (9) is used in temperature control to achieve precise temperature regulation and control. Therefore, a compatible electrical control box is required. The thermoelectric cooler (9) serves as the core component of the temperature control system, maintaining the stability of the set temperature. When the ambient temperature exceeds the set value, current flows through the cooler, generating a cooling effect and removing heat from the control system, thus lowering the temperature. When the ambient temperature falls below the set value, the cooler stops supplying power and ceases cooling to maintain a stable temperature. The electrical control box uses a PLC controller to adjust the supply current, thereby changing the cooling power of the thermoelectric cooler (9) and regulating the temperature of the control system. This method allows for rapid response to temperature changes, achieving precise temperature control.

[0041] In this scheme, due to the two-stage cooling and the fact that the rotation speed also affects airflow and temperature control, feedback control is required in the initial stage of system operation. This can be achieved using a PID controller. Taking this scheme as an example, firstly, the system temperature setpoint is determined, i.e., the target temperature to which the system temperature is to be adjusted. Then, the cylinder area is divided into two smaller areas, with a semiconductor cold source 2 placed in each area. The division of the areas can be based on actual needs and factors such as the size of the cylinder and the heat load distribution.

[0042] Afterwards, temperature probe 22 can be used to measure the temperature at different locations in the cold well cylinder 4 and provide it as a feedback signal to the PID controller. The PID controller calculates the error between the feedback signal and the set value to generate a corresponding control signal. Simultaneously, the rotational speed of the power source 10 needs to be adjusted during this process. At this point, the proportional, integral, and derivative parameters need to be adjusted according to the actual application and performance requirements (based on the source cylinder volume and the model of the semiconductor cooling chip 9) to optimize the control system's response speed, stability, and anti-interference capability. Finally, by continuously monitoring and adjusting the output of the PID controller, the system temperature gradually approaches the set temperature and is maintained within a certain range.

[0043] In practical applications, each group of semiconductor cooling sources 2 can be equipped with an independent PID controller, enabling it to independently control the system based on the temperature feedback signal of its respective area. Each PID controller can perform cooling operations according to the temperature deviation of its own area. This allows the operating state of the corresponding semiconductor cooling chip 9 to be adjusted according to the magnitude of the temperature deviation in different areas. When the temperature in a certain area is too high, the power of the corresponding semiconductor cooling chip 9 is increased; when the temperature in a certain area is too low, the power of the semiconductor cooling chip 9 is reduced and its rotation speed is increased to improve airflow.

[0044] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A phosphorus diffusion control device for chip manufacturing, characterized in that: The system includes a source temperature cold well (1), several semiconductor cold sources (2), and a temperature equalization duct module (3). The source temperature cold well (1) includes a vertical cold well cylinder (4) and an upper pressure cover (5) set on the top of the cold well cylinder (4). The cold well cylinder (4) is provided with several cold source mounting seats (6) from top to bottom, and each cold source mounting seat (6) contains a semiconductor cold source (2). The semiconductor cold source (2) includes a slewing bearing (7) set on the cold source mounting seat (6), a temperature equalization mounting cylinder (8) set on the rotating end of the slewing bearing (7) and used for coaxial rotation with the cold well cylinder (4), and several semiconductor cooling chips (8) surrounding the temperature equalization mounting cylinder. 9) and a control power source (10) for driving the rotation of the rotating end of the slewing bearing (7). Each semiconductor cooling chip (9) has a fin (11) extending into the cold well cylinder (4) on its cooling surface. The temperature equalization duct module (3) includes a guide air ring (12) coaxially connected to the temperature equalization mounting cylinder (8) and located in the cold well cylinder (4) and a suspension frame (13) for carrying the liquid source bottle. The suspension frame (13) has multiple hollows on its circumference and bottom, which separate the circumference and bottom of the liquid source bottle from the cold well cylinder (4) to form a temperature equalization duct. The guide air ring (12) surrounds the suspension frame (13) and is used to generate airflow between the upper and lower layers by rotation.

2. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: Multiple connecting plates (14) are arranged from top to bottom inside the cold well cylinder (4). Vertical slides (15) are fixedly provided on the connecting plates (14), and the suspension frame (13) is slidably connected to the vertical slides (15).

3. The phosphorus diffusion control device for chip manufacturing according to claim 2, characterized in that: The cold well cylinder (4) is composed of several independent cylinders, which are connected as a whole by connecting the cold source mounting base (6) on the upper or lower side.

4. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: The control power source (10) includes a gear ring (16) coaxially and fixedly mounted on the rotating end of the slewing bearing (7), a drive motor (17) fixedly mounted on the cold source mounting base (6), and a transmission gear (18) mounted on the drive motor (17) and used to mesh with the gear ring (16).

5. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: The positive and negative terminals of several semiconductor cooling chips (9) of the same semiconductor cold source (2) are respectively connected to an annular conductor (19) fixedly installed on the outer periphery of the temperature equalization installation cylinder (8). The annular conductor (19) is electrically connected to the electrical control box through the sliding contact line (20).

6. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: current guiding... The air ring (12) includes several guide vanes (21) evenly distributed around the temperature equalization mounting cylinder (8).

7. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: Several temperature probes (22) are installed on the inner side wall of the cold well body (4).

8. The phosphorus diffusion control device for chip manufacturing according to claim 7, characterized in that: A heating element (23) is provided in the temperature equalization channel at the bottom of the cold well cylinder (4), and an exhaust vent (24) is provided on the periphery of the heating element (23) in the cold well cylinder (4).

9. The phosphorus diffusion control device for chip manufacturing according to claim 1, characterized in that: The upper pressure cap (5) is detachably mounted to the cold well cylinder (4), and is provided with a latch (25) for abutting against the suspension frame (13).

10. A phosphorus diffusion control device for chip manufacturing according to claim 9, characterized in that: The top of the cold well body (4) is provided with a locking mechanism for locking the upper pressure cover (5).

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