A zoned heated semiconductor crystal pulling apparatus

Abstract

A kind of partition heating semiconductor smelting crystal pulling device, it is related to semiconductor processing manufacturing technical field, including furnace body, multiple temperature-controlled heating zones are provided in furnace body inner cavity, and the heating zone includes growth temperature zone;Interface temperature monitoring mechanism is further arranged in the inner cavity of furnace body to monitor the solid-liquid interface temperature at the crucible;Rotary lifting mechanism is arranged at the top of furnace body;Rotary lifting mechanism rod passes through the upper end of furnace body and extends into the crystal pulling rod of growth temperature zone, and the rotary lifting mechanism drives the lifting and rotation of crystal pulling rod;Rotary lifting mechanism further includes rotating base, which drives rotary lifting mechanism to rotate when crystal pulling rod reaches the set height, through the precise temperature field of integrated multi-temperature zone, forced convection of rotary stirring, process flexibility of vertical pulling, and realize multi-system linkage control based on interface real temperature, meet the growth demand of high-precision materials such as multi-component compound semiconductor.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing and manufacturing technology, and specifically to a semiconductor melting and crystal pulling apparatus with zoned heating. Background Technology

[0002] Liquid phase epitaxy (LPE) is one of the key technologies for preparing single-crystal thin films of compound semiconductors, and its equipment structure directly determines the quality of crystal growth and process adaptability. After years of development, five mainstream LPE furnace structure types have emerged in this field: horizontal sliding type, vertical pulling type, rotary stirring type, multi-temperature zone type, and continuous growth type. These devices each have their advantages in specific application scenarios, but they also have inherent limitations and cannot simultaneously meet the comprehensive requirements of high-precision multi-component compound semiconductor growth.

[0003] Vertical pull-out LPE furnaces achieve contact and separation between the substrate and the melt by raising and lowering the seed crystal rod, offering flexible processing and being particularly suitable for the growth of multilayer heterostructures. However, the melt mainly relies on natural diffusion to achieve uniform composition, which can easily lead to uneven solute distribution, affecting the thickness and compositional consistency of the epitaxial layer. Furthermore, the temperature field is usually controlled by a single heating element, limiting the ability to adjust the axial temperature gradient.

[0004] Rotary stirring LPE furnaces introduce forced convection through crucible or seed crystal rotation, which significantly improves melt uniformity and is beneficial for the growth of large-area epitaxial layers. However, the temperature field control of such equipment is relatively simple, making it difficult to establish an ideal temperature gradient at the solid-liquid interface. The mechanical disturbance caused by rotation may also affect the interface stability.

[0005] Multi-zone LPE furnaces employ multiple independent heating zones, which can form a flexible and adjustable linear or segmented temperature gradient along the axis, providing a hardware foundation for precise control of thermodynamic subcooling. However, their temperature control logic is usually based on temperature feedback from the furnace wall or heating elements. Due to the difference in thermal resistance and radiation, it is an indirect temperature measurement, which has lag and deviation, making it difficult to achieve accurate and repeatable temperature control.

[0006] In summary, existing LPE equipment suffers from trade-offs in terms of temperature field control precision, melt uniformity, and process flexibility: multi-zone furnaces offer high temperature control precision but poor melt uniformity, rotary stirring furnaces produce uniform melts but have coarse temperature field control, and vertical pulling furnaces offer flexible processes but have a single temperature field. Therefore, there is an urgent need for a composite LPE equipment that can integrate the precise temperature field of multiple zones, the forced convection of rotary stirring, and the process flexibility of vertical pulling, and achieve multi-system linkage control based on the actual interface temperature to meet the growth requirements of high-precision materials such as multi-component compound semiconductors. Summary of the Invention

[0007] I. Technical problems to be solved To address the shortcomings of existing technologies, this invention proposes a semiconductor melting and crystal pulling device with zoned heating. By integrating a precise temperature field across multiple temperature zones, forced convection through rotary stirring, and process flexibility through vertical pulling, and achieving multi-system linkage control based on the actual interface temperature, it effectively meets the growth requirements of high-precision materials such as multi-component compound semiconductors.

[0008] II. Specific Technical Solutions A semiconductor melting and crystal pulling apparatus with zoned heating includes a furnace body. Multiple independently temperature-controlled heating zones are arranged axially within the furnace body, each including at least one growth temperature zone. A crucible is disposed within the growth temperature zone, and a rotary drive mechanism is provided at the bottom of the crucible to drive its rotation. An interface temperature monitoring mechanism is also provided within the furnace body to monitor the solid-liquid interface temperature at the crucible. A rotary pulling mechanism is disposed at the top of the furnace body. The rotary pulling mechanism includes a crystal pulling rod that passes through the upper end of the furnace body to extend into the growth temperature zone. This rotary pulling mechanism drives the crystal pulling rod to rise, fall, and rotate during the crystal pulling process. The rotary pulling mechanism also includes a rotating base, which drives the rotary pulling mechanism to rotate when the crystal pulling rod reaches a set height.

[0009] Implementation principle and working principle: The basic principle of this scheme is to achieve flexible control of the axial temperature gradient through multiple independent temperature-controlled heating zones set along the axial direction in the furnace, with the growth temperature zone being the core growth area; the rotation drive mechanism at the bottom of the crucible drives the crucible to rotate, causing forced convection in the melt and achieving homogenization of the melt composition; the interface temperature monitoring mechanism directly monitors the solid-liquid interface temperature at the crucible, providing real-time and accurate feedback data for temperature field control; the crystal pulling rod of the rotating pulling mechanism can simultaneously achieve lifting (controlling the crystal growth rate) and rotation (improving the interface diffusion layer) during the crystal pulling process, combining the dual functions of vertical pulling and rotational stirring; the innovation of the rotating base is that when the crystal pulling rod rises to the set height (i.e., after the crystal growth is completed and it detaches from the melt), it drives the entire rotating pulling mechanism to rotate and move away, providing operating space for subsequent crystal removal or crucible replacement.

[0010] Preferably, the top of the furnace body is provided with a flip-up door, which is used to open after the product is formed, so that the formed product can pass through the top of the furnace body when the crystal pulling rod rises, and the crystal pulling rod can enter the furnace body after the product is unloaded. The beneficial effect of this preferred embodiment is that the flip-up door is located at the top of the furnace body and is normally closed to maintain the sealed environment (such as protective atmosphere, pressure, etc.) inside the furnace body. When the crystal growth is completed and the crystal pulling rod rises to the top, the flip-up door opens to provide a channel for the crystal (product) to be taken out from the top of the furnace body. After the crystal is taken out, the flip-up door closes, and the crystal pulling rod can descend again into the furnace body to start a new round of growth. This realizes the vertical crystal taking from the top of the furnace body, avoiding the complex mechanical structure required for traditional side or bottom crystal taking, and also reducing heat exchange with the outside world and reducing energy consumption.

[0011] Preferably, the flip door has at least two panels, rotatably connected to the top of the furnace body, and also includes a flip door drive mechanism, which drives the flip doors to rotate simultaneously to achieve closing and opening. The advantages of this preferred embodiment are that the flip door is designed as a structure with at least two or more panels that open and close, and each panel is rotatably connected and installed on the top of the furnace body; the flip door drive mechanism (such as a motor, cylinder and transmission mechanism) drives each panel to rotate synchronously, achieving smooth opening and closing of the door; the multi-panel design allows a larger opening to be formed in the center after the door is opened, facilitating the passage of crystals, while the size of each panel is small, making opening and closing more flexible, and its flip or sliding type will not occupy the space inside the furnace.

[0012] Preferably, the rotating lifting mechanism further includes a displacement sensor, which is used to detect the height parameter of the crystal pulling rod. The flip-door driving mechanism drives the flip-door to open and close according to the height parameter detected by the displacement sensor. The beneficial effect of this preferred embodiment is that the displacement sensor monitors the height position of the crystal pulling rod in real time and transmits the height signal to the controller. The controller makes a judgment based on preset logic: when the crystal pulling rod rises to the predetermined opening height, it issues an opening command to the flip-door driving mechanism; when the crystal pulling rod falls to the predetermined closing height or after the crystal is removed, it issues a closing command. This realizes automatic linkage control between the height of the crystal pulling rod and the opening and closing of the flip-door, and achieves intelligent linkage control between the position of the crystal pulling rod and the opening and closing of the flip-door. It avoids manual judgment and operation, improves the level of intelligence and loading and unloading efficiency, reduces the heat exchange time between the furnace body and the outside, and is also beneficial to save energy and avoid more interference from the outside to the furnace body.

[0013] Preferably, the system also includes a frame, with the rotating base and furnace body respectively disposed on the upper and lower sides of the frame. A furnace body lifting mechanism is also provided between the furnace body and the frame. The furnace body lifting mechanism includes a function to adjust the height of the furnace body according to the solid-liquid interface. The beneficial effect of this preferred embodiment is that this technical solution provides a temperature field adjustment method different from the traditional "crystal pulling rod lifting". The furnace body is mounted on the frame through the furnace body lifting mechanism and can move up and down relative to the fixed rotating lifting mechanism. During crystal growth, the position of the solid-liquid interface is monitored by the interface temperature monitoring mechanism. When it is necessary to adjust the relative position of the solid-liquid interface in the temperature field (for example, to keep the interface always in the optimal temperature gradient zone), the controller controls the furnace body lifting mechanism to lift the entire furnace body, thereby changing the relative position of the melt in the crucible and the fixed temperature field, so that the solid-liquid interface is always in the optimal growth temperature zone, ensuring the consistency and reproducibility of crystal forming, and more importantly, ensuring the consistency of crystal growth.

[0014] Preferably, the device also includes a controller, which is electrically connected to the heating zone, the rotary drive mechanism, the interface temperature monitoring mechanism, the rotary pulling mechanism, and the rotating base, for temperature regulation and drive control at corresponding positions. The advantage of this preferred embodiment is that the controller, as the control core of the entire device, receives the solid-liquid interface temperature signal fed back by the interface temperature monitoring mechanism, and, based on preset process parameters or real-time calculation results, issues power adjustment commands to the heating zone to adjust the temperature gradient, speed adjustment commands to the rotary drive mechanism to control the melt convection intensity, lifting and rotation speed commands to the rotary pulling mechanism to control the crystal growth process, and rotation commands to the rotating base to achieve automatic removal of the crystal pulling rod. All actuators work collaboratively under the unified coordination of the controller, forming a complete closed-loop control system.

[0015] Preferably, the interface temperature monitoring mechanism includes: multiple sets of temperature zone sensors, each set being disposed in each heating zone, with each set monitoring the furnace body temperature on a corresponding side of a heating zone; and at least one set of crucible temperature sensors, disposed at the bottom or side wall of the crucible, for directly monitoring the temperature of the melt inside the crucible; the controller receives the monitoring signals from the temperature zone sensors and the crucible temperature sensors, and corrects the set value of the temperature zone sensors based on the monitoring data from the crucible temperature sensors, thereby achieving precise control of the solid-liquid interface temperature; the controller is further configured to adjust the set value of the temperature zone sensors based on the melt temperature monitored by the crucible temperature sensors and a preset target value. The deviation of the set temperature is compensated by feedforward for the set values ​​of the multiple temperature zone sensors, and the heating power of each heating zone is adjusted according to the compensated set values. The beneficial effect of this preferred method is that it realizes a dual temperature measurement system of "furnace temperature monitoring + melt temperature monitoring", which solves the measurement deviation problem caused by traditional equipment that only monitors the furnace wall temperature. By correcting the furnace temperature set value through feedback of the actual melt temperature, more accurate control of the solid-liquid interface temperature is achieved. The two-stage temperature measurement system complements each other. The temperature zone sensors ensure the basic temperature control of each temperature zone, and the crucible temperature sensor provides accurate calibration basis, which is particularly suitable for the growth of high-quality multi-component compound semiconductors that are sensitive to temperature.

[0016] Preferably, the rotary drive mechanism includes a vertically arranged hollow mounting shaft; the crucible is positioned at the top of the mounting shaft; a crucible temperature sensor for detecting the crucible temperature is located in the middle of the mounting shaft; a rotary bearing base and a crucible drive motor are located at the bottom of the mounting shaft, and the output end of the crucible drive motor drives the mounting shaft to rotate via gears. The advantages of this preferred embodiment are that the rotary drive mechanism drives the hollow mounting shaft to rotate via the crucible drive motor and gear transmission, thereby driving the crucible at the top to rotate, resulting in a crucible rotation speed of 0-5 rpm. The crucible's rotation drives the melt flow, achieving forced homogenization of the melt composition without causing significant material oscillations, thus ensuring forming stability. The hollow structure of the mounting shaft facilitates the arrangement of wiring within the shaft. The crucible temperature sensor is located in the middle of the mounting shaft. Since the mounting shaft is directly connected to the crucible, for example, via a slip ring, this position can accurately sense the temperature at the bottom of the crucible, providing temperature data closer to the heat source for temperature field control.

[0017] Preferably, a lower insulation layer is also provided at the bottom of the mounting shaft. This lower insulation layer and the furnace body are at the same height during heating. A cooling component is provided at the bottom of the lower insulation layer, and a sealing ring is provided between the cooling component and the lower insulation layer. The advantages of this preferred embodiment are that the lower insulation layer, located at the bottom of the mounting shaft, is flush with the bottom of the furnace body during heating, forming a heat insulation barrier at the bottom of the furnace chamber, reducing heat loss from the bottom. The cooling component is located below the lower insulation layer to appropriately cool it, preventing heat from being conducted downwards and damaging the drive components. The sealing ring is located between the lower insulation layer and the cooling component, providing a seal and preventing the cooling component from affecting the lower insulation layer. This ensures that the lower insulation layer has good insulation performance while avoiding deformation and cracking caused by high temperatures.

[0018] Preferably, a venting pipe is provided on the side of the lower insulation layer near the upper surface. This venting pipe has multiple air outlets, which are evenly spaced around the circumference of the lower insulation layer. The air outlets are tangentially aligned with the circumference of the lower insulation layer and inclined upwards, forming a heat-insulating air curtain with the bottom of the furnace body. The beneficial effect of this preferred embodiment is that a ring of air outlets is provided around the upper surface of the lower insulation layer, and inert gases (such as argon or nitrogen) are introduced through the venting pipe. The air outlets are designed to be tangentially aligned with the circumference of the lower insulation layer and inclined upwards. This causes the ejected gas to form a rotating and rising airflow along the inner wall of the furnace body, forming a continuous air curtain barrier between the bottom of the furnace body and the lower insulation layer. This air curtain has a dual function: on the one hand, it prevents the high-temperature heat inside the furnace from radiating and conducting downwards, thus providing heat insulation; on the other hand, the rotating and rising airflow can carry away impurities that may be deposited at the bottom, keeping the furnace clean.

[0019] The beneficial effects of this invention are as follows: 1. By using multiple independent temperature-controlled heating zones to flexibly set the axial temperature gradient, combined with an interface temperature monitoring mechanism to directly monitor the solid-liquid interface temperature, and a crucible temperature sensor to monitor the crucible temperature, a multi-level precise temperature measurement and control system is formed, with a temperature control accuracy of ±0.1℃.

[0020] 2. The crucible rotates under the drive of the rotary drive mechanism, which causes the melt to generate forced convection. Combined with the rotation of the crystal pulling rod, it achieves forced homogenization of the melt composition and avoids the problem of uneven composition caused by natural diffusion in traditional equipment.

[0021] 3. The crystal pulling rod has both lifting and rotating functions. Combined with the furnace body lifting mechanism to adjust the furnace body height, it can flexibly realize the pull-and-release growth of multi-layer heterostructures, meeting the complex growth process requirements of multi-component compound semiconductors.

[0022] 4. The controller provides unified and coordinated control of all actuators to achieve full-process automation; the rotating base is linked with the flip door, and the displacement sensor is linked with the flip door drive mechanism, which realizes the automatic removal of the crystal pulling rod and the automatic opening and closing of the flip door, significantly improving the crystal extraction efficiency and automation level.

[0023] 5. The composite design of the lower insulation layer, insulation layer cooling components, sealing ring and tangential air curtain ensures the insulation effect at the bottom, effectively prevents heat from being conducted downward and damaging precision components, and forms a heat insulation barrier through the air curtain, achieving both thermal field control and mechanical sealing.

[0024] 6. Precise temperature measurement provides the foundation for the coordinated control of the temperature zone, pulling, and rotation systems; the furnace body lifting and the crystal pulling rod lifting form a dual adjustment mechanism; the air curtain insulation and bottom insulation form a dual thermal field protection; this synergistic effect enables the device of this invention to meet the growth requirements of high-precision materials such as multi-component compound semiconductors, and solves the problem of difficult coordinated control of temperature field, flow field and growth interface in the prior art. Attached Figure Description

[0025] Figure 1 This is a side view of the semiconductor melting and crystal pulling apparatus with zoned heating in this embodiment.

[0026] Figure 2 This is a cross-sectional view of the semiconductor melting and crystal pulling apparatus with zoned heating in this embodiment.

[0027] Figure 3 This is a cross-sectional schematic diagram of the melting position in the semiconductor melting and crystal pulling apparatus with zoned heating in this embodiment.

[0028] Explanation of reference numerals in the attached figures: Furnace body 1, heating zone 101, growth temperature zone 102, flip door 103, flip door drive mechanism 104, furnace body lifting mechanism 105, crucible 2, rotation drive mechanism 201, mounting shaft 202, crucible temperature sensor 302, rotation bearing base 204, crucible drive motor 205, lower insulation layer 206, insulation layer cooling assembly 207, sealing ring 208, gas outlet 209, interface temperature monitoring mechanism 3, rotation lifting mechanism 4, crystal pulling rod 401, rotating base 402, displacement sensor 403, frame 5, controller. Detailed Implementation

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] Example 1 like Figure 1-3 As shown, this embodiment provides a semiconductor melting and crystal pulling device with zoned heating, including a furnace body 1, a crucible 2, a rotary drive mechanism 201, an interface temperature monitoring mechanism 3, a rotary pulling mechanism 4, a frame 5, and a controller.

[0031] The furnace body 1 is a vertical cylindrical structure made of quartz tube or stainless steel, forming a sealed growth chamber inside, and is equipped with heat-insulating bricks and heat-insulating blankets on the outside. The inner cavity of the furnace body 1 has five independently temperature-controlled heating zones 101 arranged vertically or axially. Each heating zone 101 is equipped with an independent heating element, such as a resistance wire and a thermocouple. In this embodiment, a platinum-rhodium S-type thermocouple is used to detect the temperature with an accuracy of ±0.1℃. There are 6 of them, corresponding to each heating zone 101 and the crucible 2. In this embodiment, the five heating zones 101 include a growth temperature zone 102 located in the middle. The temperature on the upper and lower sides of the growth temperature zone 102 is symmetrically gradient-distributed to facilitate the temperature stability of the growth temperature 102. This area is the core area for crystal growth.

[0032] A crucible 2 is provided in the growth temperature zone 102 for holding the raw material melt. A rotary drive mechanism 201 is provided at the bottom of the crucible 2. The rotary drive mechanism 201 includes a vertically arranged hollow mounting shaft 202, and the crucible 2 is fixed to the top of the mounting shaft 202. A crucible temperature sensor 204 is provided in the middle of the mounting shaft 202 for detecting the temperature at the bottom of the crucible 2. A rotary bearing base 205 and a crucible drive motor 206 are provided at the bottom of the mounting shaft 202. Specifically, a drive gear is provided at the output end of the crucible drive motor 206, and a driven wheel that meshes with the drive gear is provided at the bottom of the mounting shaft 202. The output end of the crucible drive motor 206 meshes with the gear ring on the mounting shaft 202 through the gear, driving the mounting shaft 202 and the crucible 2 to rotate at a speed of 0-5 RPM. Specifically, the speed can be adjusted and controlled by a controller.

[0033] The interface temperature monitoring mechanism 3 includes: multiple sets of temperature zone sensors 301, each set of temperature zone sensors 301 being disposed in each heating zone, with each set of temperature zone sensors 301 monitoring the furnace body temperature on the corresponding side of a heating zone; and at least one set of crucible temperature sensors 302, disposed at the bottom or side wall of the crucible 2, in this embodiment disposed at the bottom, for directly monitoring the temperature of the melt inside the crucible 2; during implementation, the controller receives the monitoring signals from the temperature zone sensors 301 and the crucible temperature sensors 302, and corrects the set values ​​of the temperature zone sensors based on the monitoring data of the crucible temperature sensors to achieve precise control of the solid-liquid interface temperature; the controller is also configured to adjust the set values ​​of the temperature zone sensors based on the crucible temperature data. The deviation between the melt temperature monitored by the temperature sensor and the preset target temperature is used to feedforward compensation of the set values ​​of the multiple temperature zone sensors, and the heating power of each heating zone is adjusted according to the compensated set values. This realizes a dual temperature measurement system of "furnace temperature monitoring + melt temperature monitoring", which solves the measurement deviation problem caused by traditional equipment that only monitors the furnace wall temperature. By correcting the furnace temperature set value through feedback of the actual melt temperature, more accurate control of the solid-liquid interface temperature is achieved. The two-stage temperature measurement system complements each other. The temperature zone sensors ensure the basic temperature control of each temperature zone, and the crucible temperature sensor provides accurate calibration basis, which is particularly suitable for the growth of high-quality multi-component compound semiconductors that are sensitive to temperature.

[0034] A rotary lifting mechanism 4 is provided on the top of the furnace body 1; the rotary lifting mechanism 4 includes a crystal pulling rod 401 and a rotating base 402; the lower end of the crystal pulling rod 401 passes through the top of the furnace body 1 and extends into the growth temperature zone 102, and the upper end is connected to a rotary drive unit, which specifically adopts a servo motor + reducer, and controls the output of the servo motor rotation speed according to a set program; it also includes a lifting drive unit, which in this solution specifically adopts a servo motor and lead screw cooperation, driving the rotary drive unit and the crystal pulling rod 401 to rise and fall on the lead screw, wherein the rising and falling speed is... The speed range is configured to be no higher than 2000 mm / h and is adjustable, making it easy to set according to different materials. Based on this, the crystal pulling rod achieves a combined lifting and rotating motion under the drive of the rotary lifting mechanism 4. The rotating base 402 is mounted on the frame 6, and the rotary lifting mechanism 4 is mounted entirely on the rotating base 402. The rotating base 402 includes a servo motor and a mounting turntable. The mounting turntable is used to rotate the mounting of the lifting mechanism 4. The mounting turntable is connected to the reducer at the output end of the servo motor through gear teeth to realize the overall rotation of the rotary lifting mechanism 4. When the crystal pulling rod 401 rises to the set height (when the crystal completely leaves the melt and enters the cooling zone), the rotating base 402 drives the entire rotary lifting mechanism 4 to rotate horizontally by 90°-180°, so that the crystal pulling rod 401 and the grown crystal are moved out of the furnace body 1, making room for crystal removal or crucible replacement.

[0035] The top of the furnace body 1 is also provided with a flip door 103. In this embodiment, the flip door 103 is a two-panel double-opening structure, which is connected to the top of the furnace body 1 by hinges. A sliding double-opening door can also be used. The flip door drive mechanism 104 (such as a motor + reducer or cylinder) is connected to the flip door 103 and is used to drive it to open and close synchronously. The top of the rotating lifting mechanism 4 is provided with a displacement sensor 403, which is used to detect the height position of the crystal pulling rod 401 in real time. In this embodiment, the displacement sensor 403 specifically collects the height change of the lifting unit as the height position of the crystal pulling rod 401. The controller 6 receives the signal from the displacement sensor 403. When the crystal pulling rod 401 rises to the opening height, it controls the flip door drive mechanism 104 to drive the flip door 103 to open. When the crystal is taken out and the crystal pulling rod 401 falls to the closing height, it controls the flip door drive mechanism 104 to drive the flip door 103 to close.

[0036] A furnace body lifting mechanism 105 is also provided between the furnace body 1 and the frame 6. The furnace body lifting mechanism 105 includes a guide rail, a slider and a drive motor, which is used to drive the furnace body 1 to adjust the overall height according to the position of the solid-liquid interface, so as to match the relative position of the crystal pulling rod 401 or adjust the position of the solid-liquid interface in the temperature field. Specifically, a weighing sensor can be set at the bottom of the rotating base 402. The weighing sensor calculates the weight difference data before and after the crystal pulling is completed. The weight difference data represents the amount of material reduction in the crucible. The controller can determine the amount of change of the solid-liquid interface based on the change of this data, and then drive the furnace body 1 to move up and down on the frame, so that the interface temperature detection mechanism and temperature zone can always adapt to the material change in the crucible, resulting in better consistency and reproducibility of the produced crystals. When the monitoring value of the weighing sensor records that the generated material has reached the maximum amount of material generated in the crucible, the controller drives the furnace body lifting mechanism to lift and lower, so that the crucible 2 is exposed from the bottom of the furnace body 1, which is convenient for changing materials or directly replacing the dry crucible 2.

[0037] like Figure 2 and 3 As shown, a lower insulation layer 207 is provided at the bottom of the mounting shaft 202. When the furnace body 1 is heated, the lower insulation layer 207 and the bottom of the furnace body 1 are at the same height, forming a bottom insulation structure together, which is not sealed. An insulation layer cooling component 208 is provided at the bottom of the lower insulation layer 207. In this embodiment, a circulating water cooling jacket is specifically used, and the lower insulation layer 207 and the insulation cooling component 208 are sealed by a sealing ring 209 to ensure the airtightness of the bottom of the furnace body and to cool the lower insulation layer.

[0038] A ventilation pipe is provided on the side of the lower insulation layer 207 near the upper surface. Under the action of the temperature zone, the upper surface of the lower insulation layer 207 is heated, thereby preheating the ventilation pipe. The ventilation pipe is provided with multiple air outlets 210. Since the gas at the air outlets 210 has been preheated, its impact on the temperature inside the furnace is very small. The air outlets 210 are evenly spaced around the lower insulation layer 207, and the gas outlet direction is along the circumferential tangent of the lower insulation layer and inclined upward. During operation, an inert gas (such as argon) is introduced, and the gas is ejected from the air outlets 210, forming a heat-insulating gas curtain that rotates and rises along the inner wall of the furnace. On the one hand, it prevents heat from being conducted downward, and on the other hand, it cleans the bottom of the furnace. At the same time, the closed method has advantages. First, the introduced inert gas can form protection during the crystal pulling process. Second, the introduced preheated gas has little impact on the temperature inside the furnace. Third, since it is a gas-sealed method, it is convenient to raise and lower the furnace body 1 and the heating zone 101 as a whole.

[0039] The controller is electrically connected to the heating zone 101, the rotary drive mechanism 201 (crucible drive motor 206), the interface temperature monitoring mechanism 3, the rotary lifting mechanism 4 (lifting and rotating drive unit), the rotating base 402, the displacement sensor 403, the flip door drive mechanism 104, the furnace body lifting mechanism 105, and the crucible temperature sensor 204, respectively. Based on the solid-liquid interface temperature fed back by the interface temperature monitoring mechanism 3 and the crucible temperature fed back by the crucible temperature sensor 204, the controller uses a PID control algorithm to synchronously adjust the heating power of the five heating zones 101, the rotation speed of the crucible 2, and the lifting and rotation speed of the crystal pulling rod 401 to maintain the preset subcooling at the solid-liquid interface.

[0040] Work process Preparation stage: Place the raw materials in crucible 2, close the flip door 103, and introduce a protective atmosphere (such as argon, hydrogen or mixed gas) into the furnace body 1; the controller controls the heating of each heating zone 101 according to the preset process curve, so that the raw materials melt to form a melt.

[0041] Crystal development stage: The furnace body lifting mechanism 105 adjusts the height of the furnace body 1 so that the solid-liquid interface is in the optimal position of the growth temperature zone 102. The rotating lifting mechanism 4 drives the crystal pulling rod 401 to descend so that the seed crystal at the lower end contacts the melt surface.

[0042] Growth stage: Based on the temperature feedback from the interface temperature monitoring mechanism 3, the controller adjusts the power of each heating zone, the crucible rotation rate, the lifting rate and rotation rate of the crystal pulling rod 401 in real time, so as to achieve coordinated control of the temperature field, flow field and growth interface. The crystal pulling rod 401 rises slowly at a preset rate, and the crystal grows gradually.

[0043] Crystal removal stage: After crystal growth is completed, the crystal pulling rod 401 rises to the preset height, the displacement sensor 403 detects the displacement signal, the controller controls the flip door drive mechanism 104 to open the flip door 103, the crystal pulling rod 401 continues to rise until it is completely separated from the furnace body, and then the rotating base 402 drives the entire rotating lifting mechanism 4 to rotate and move away, so that the operator or robot can take away the crystal.

[0044] Reset phase: After the crystal is removed, the rotating base 402 drives the rotating lifting mechanism 4 to return to its original position, the crystal pulling rod 401 descends, and the furnace body 1 and the heating zone inside it also descend as the amount of material generated by the crystal decreases. Then the flip door 103 closes and the next growth begins.

[0045] In other embodiments, the number of heating zones 101 can be three, four, or more, not limited to five; the flip door 103 can be a single-leaf, three-leaf, or four-leaf structure; the insulation layer cooling assembly 208 can be air-cooled, oil-cooled, or other cooling methods; the angle of the air outlet 210 can be optimized and adjusted according to the thermal field simulation results. The rotation angle of the rotating base 402 is not limited to 90° and can be set to any angle according to the operating space requirements.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims.

Claims

1. A semiconductor melting and crystal pulling apparatus with zoned heating, characterized in that: The furnace includes a furnace body (1), the inner cavity of which is provided with multiple independently temperature-controlled heating zones (101) along the axial direction, each heating zone (101) including at least one growth temperature zone (102); a crucible (2) is provided in the growth temperature zone (102), and a rotary drive mechanism (201) for driving the crucible (2) to rotate is provided at the bottom of the crucible (2); the inner cavity of the furnace body (1) is also provided with an interface temperature monitoring mechanism (3) for monitoring the solid-liquid interface temperature at the crucible (2); and a rotary lifting mechanism. (4) The rotating lifting mechanism (4) is set at the top of the furnace body (1). The rotating lifting mechanism (4) includes a crystal pulling rod (401), which passes through the upper end of the furnace body (1) and extends into the growth temperature zone (102). The rotating lifting mechanism (4) drives the crystal pulling rod (401) to rise, fall and rotate during the crystal pulling process. The rotating lifting mechanism (4) also includes a rotating base (402), which is used to drive the rotating lifting mechanism (4) to rotate when the crystal pulling rod (401) reaches a set height.

2. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 1, characterized in that: The top of the furnace body (1) is provided with a flip door (103), which is used to open after the product is formed, so that the formed product can pass through the top of the furnace body (1) when the crystal pulling rod (401) rises, and after the product is unloaded, the crystal pulling rod (401) enters the furnace body (1).

3. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 2, characterized in that: The flip door (103) has at least two panels, which are rotatably connected to the top of the furnace body (1). It also includes a flip door drive mechanism (104), which is used to drive the flip door (103) to rotate simultaneously to achieve closing and opening.

4. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 3, characterized in that: The rotary lifting mechanism (4) also includes a displacement sensor (403), which is used to detect the height parameter of the crystal pulling rod (401). The flip door driving mechanism (104) drives the flip door (103) to open and close according to the height parameter detected by the displacement sensor (403).

5. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 1, characterized in that: It also includes a frame (5), the rotating base (402) and the furnace body (1) are respectively arranged on the upper and lower sides of the frame (5), and a furnace body lifting mechanism (105) is also provided between the furnace body (1) and the frame (5). The furnace body lifting mechanism (105) includes a height adjustment mechanism for driving the furnace body (1) according to the solid-liquid interface.

6. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 1, characterized in that: It also includes a controller, which is electrically connected to the heating zone (101), the rotary drive mechanism (201), the interface temperature monitoring mechanism (3), the rotary lifting mechanism (4) and the rotating base (402) for temperature adjustment and drive control at the corresponding positions.

7. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 6, characterized in that, The interface temperature monitoring mechanism (3) includes: multiple temperature zone sensors (301), which are respectively set in each heating zone (101), and each set of temperature zone sensors monitors the furnace body temperature on the corresponding side of a heating zone (101); it also includes at least one set of crucible temperature sensors (302), which are set at the bottom or side wall of the crucible (2) for directly monitoring the temperature of the melt in the crucible; the controller (6) receives the monitoring signals of the temperature zone sensors and the crucible temperature sensors (302), and corrects the set value of the temperature zone sensors according to the monitoring data of the crucible temperature sensors (302) to achieve precise control of the solid-liquid interface temperature; the controller (6) is also configured to perform feedforward compensation on the set value of the multiple sets of temperature zone sensors according to the deviation between the melt temperature monitored by the crucible temperature sensors (302) and the preset target temperature, and adjust the heating power of each heating zone (101) according to the compensated set value.

8. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 1, characterized in that: The rotary drive mechanism (201) includes a vertically arranged mounting shaft (202), which is a hollow mounting shaft; the crucible (2) is located at the top of the mounting shaft (202); a crucible temperature sensor (302) for detecting the temperature of the crucible (2) is provided in the middle of the mounting shaft (202); a rotary bearing base (204) and a crucible drive motor (205) are provided at the bottom of the mounting shaft (202), and the output end of the crucible drive motor (205) drives the mounting shaft (202) to rotate through gears.

9. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 8, characterized in that: The bottom of the mounting shaft (202) is also provided with a lower insulation layer (206), and the lower insulation layer (206) and the furnace body (1) are at the same height as the bottom of the furnace body (1) when heated; the bottom of the lower insulation layer (206) is provided with an insulation layer cooling component (207), and a sealing ring (208) is provided between the insulation layer cooling component (207) and the lower insulation layer (206).

10. The semiconductor melting and crystal pulling apparatus with zoned heating according to claim 9, characterized in that: A ventilation pipe is provided on the side of the lower insulation layer (206) near the upper surface. The ventilation pipe is provided with multiple air outlets (209). The air outlets (209) are evenly spaced around the lower insulation layer (206), and the air outlet direction is along the circumferential tangent of the lower insulation layer and inclined upward, and cooperates with the bottom of the furnace body (1) to form a heat insulation air curtain.

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