Multi-temperature zone tube furnace for large-area high-uniformity material preparation

Abstract

This invention discloses a multi-temperature zone tube furnace for the preparation of large-area, highly uniform materials. The multi-temperature zone tube furnace includes a furnace tube chamber containing a substrate placement arm, and a heating electrocoupling wire assembly covering the outside of the furnace tube chamber. A substrate lifting system is connected to the substrate placement arm within the furnace tube chamber, and is used to lift the substrate placement arm, allowing the substrate to move within the growth zone under the action of the substrate placement arm. A raw material boat lifting system is connected to a raw material boat within the raw material chamber, and is used to lift the raw material boat, allowing the raw material boat to move within a channel formed by the raw material heating zone and the raw material chamber under the action of the raw material boat lifting system. The multi-gas channel raw material boat of this invention can achieve uniform flow of multi-channel airflow, and after passing through a gas equalization plate, it can further divide the precursor and airflow, achieving uniform growth of materials on large-area substrates. This invention has good airtightness, numerically controlled feeding and discharging, and can achieve uniform flow of airflow and precursor materials, avoiding uneven airflow distribution.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor material preparation technology, specifically relating to the field of material growth equipment with two-dimensional semiconductor materials as a typical example, and more specifically to a multi-temperature zone tube furnace for the preparation of large-area, highly uniform materials. Background Technology

[0002] As the semiconductor industry moves towards smaller process technologies, higher integration levels, and novel functional devices, the demand for large-area, high-quality, and highly uniform semiconductor materials, especially emerging two-dimensional semiconductor materials (such as transition metal chalcogenides), is becoming increasingly urgent. The fabrication of wafer-level single-crystal thin films has become a key bottleneck driving breakthroughs in next-generation electronic and optoelectronic technologies. Chemical vapor deposition (CVD) and its associated tube furnace systems, due to their ability to achieve precursor vapor-phase reaction and deposition at high temperatures, are currently one of the mainstream technologies for preparing these materials.

[0003] However, traditional tube furnace CVD technology faces a series of severe challenges when it comes to the large-scale preparation of advanced semiconductor materials, especially two-dimensional materials. First, some key semiconductor material precursors, such as certain metal halides or oxides, have physical characteristics of high evaporation temperatures and extremely low vapor pressures at room temperature. This makes it difficult to achieve a stable and controllable vapor supply in a tube furnace using conventional carrier gas methods, posing significant challenges to the repeatability and stability of the process.

[0004] Secondly, for these special precursors, traditional methods of precisely controlling the start and end of growth by controlling the carrier gas flow often fail. This is because even if the carrier gas is cut off, the residual precursor vapor in the furnace tube and the continuous evaporation from the high-temperature walls can still lead to unintentional and uncontrolled continued deposition, severely affecting the interface clarity and structural integrity of the film. To address this problem, current processes rely on the "temperature sag" method in the reaction zone after the reaction ends, i.e., rapidly cooling the substrate area below the reaction temperature to forcibly terminate the reaction. However, this method has poor temperature control precision and slow heating and cooling rates, resulting in huge energy consumption, long process cycles, and the potential for drastic temperature fluctuations to introduce thermal stress, leading to cracks or defects in the film.

[0005] A more fundamental challenge lies in the fact that current wafer-level fabrication of semiconductor materials, especially two-dimensional materials, generally suffers from extremely low uniformity. This stems from the laminar flow-dominated transport mode of traditional tube furnaces and the concentration gradient of precursors within the high-temperature region. When precursor molecules reach the growth substrate surface, their diffusion behavior exhibits significant randomness, making it difficult to achieve ordered and uniform transport on a macroscopic scale. This random and non-uniform diffusion process directly leads to the random distribution of nucleation sites and spatial non-uniformity of growth rates, ultimately resulting in significant differences in the number of layers, thickness, grain size, and even chemical composition of the prepared films, failing to meet the integration requirements of high-performance, uniform devices.

[0006] Therefore, developing a novel tube furnace system that can overcome the challenges of transporting low vapor pressure precursors, achieve precise "on / off" control of the growth process, and ultimately guide the precursors to diffuse uniformly rather than randomly is of paramount importance for breaking through the bottlenecks in the preparation of advanced semiconductor materials, especially wafer-level single-crystal two-dimensional materials. Summary of the Invention

[0007] Purpose of the invention: The present invention aims to provide a multi-temperature zone tube furnace for the preparation of large-area, highly uniform materials with precise control of the growth process.

[0008] Technical Solution: The multi-zone tube furnace of the present invention includes a furnace tube chamber, a substrate placement arm disposed within the furnace tube chamber, and a heating electrocoupling wire assembly covering the outside of the furnace tube chamber; the furnace tube chamber is divided into a growth zone and a raw material heating zone; a raw material chamber is connected to the furnace tube chamber and contains a raw material boat; a substrate lifting system is connected to the substrate placement arm within the furnace tube chamber, and the substrate lifting system is used to lift the substrate placement arm, allowing the substrate to move within the growth zone under the action of the substrate placement arm; a raw material boat lifting system is connected to the raw material boat within the raw material chamber, and the raw material boat lifting system is used to lift the raw material boat; the raw material boat moves within a channel formed by the raw material heating zone and the raw material chamber under the action of the raw material boat lifting system.

[0009] In the above technical solution, the multi-temperature zone tube furnace is equipped with a substrate lifting system and a raw material boat lifting system, which can accurately move the substrate and the raw material boat to the center of their respective temperature zones before the reaction. At the end of the reaction, the substrate can be quickly lifted to the outside of the high-temperature zone for cooling to instantly terminate the reaction, while the raw material boat is lowered to the low-temperature zone and physically isolated from the precursor with an insert-type baffle valve. This achieves precise "on / off" control of the start and end of growth, effectively avoiding the thermal stress problems caused by the traditional "sudden temperature drop" method and the unintentional deposition caused by precursor residue.

[0010] In the furnace tube chamber, both the growth zone and the raw material heating zone are cylindrical tubes, with the growth zone having a larger tube diameter than the raw material heating zone. The lower raw material zone uses a narrower tube diameter to achieve better heat preservation and meet the requirements of high evaporation temperature precursors; the upper substrate growth zone uses a larger tube diameter to accommodate large-size wafers and provide them with a uniform thermal and gas field.

[0011] The growth area is equipped with a substrate placement arm, and the top of the substrate placement arm is equipped with a molybdenum sheet partition. The molybdenum sheet partition is used to seal the furnace tube chamber. The substrate placement arm is equipped with several slots for installing substrate trolleys.

[0012] The substrate lifting system includes a first lead screw and nut lifting mechanism and a rotary motor. The nut of the first lead screw and nut lifting mechanism is connected to the substrate placement arm and is used to drive the substrate placement arm to lift and lower. The rotary motor is connected to the substrate placement arm and is used to drive the substrate placement arm to rotate.

[0013] The raw material boat lifting system includes a second screw nut lifting mechanism and a bellows. The nut of the second screw nut lifting mechanism is connected to the bellows, and the bellows is connected to the raw material boat. The second screw nut lifting mechanism is used to lift the raw material boat.

[0014] The raw material boat includes a raw material container, a gas channel, and a perforated insulating column. The gas channel runs through the bottom of the raw material container and connects to it. The perforated insulating column surrounds the gas channel. The raw material boat employs a design with multiple discrete gas channels, which can divert the carrier gas to uniformly carry the precursor vapor evaporated from the raw material.

[0015] The heating electrocoupling wire assembly consists of a first heating electrocoupling wire and a second heating electrocoupling wire. The first heating electrocoupling wire is attached to the outer surface of the growth zone, and the second heating electrocoupling wire is attached to the outer surface of the raw material heating zone. For irregularly shaped furnace tubes with a diameter larger than that of the raw material heating zone, a corresponding irregularly shaped heating electrocoupling wire assembly is required. The heating electrocoupling wire assembly employs a dual thermocouple design, with one thermocouple used for precise temperature measurement and the other for closed-loop control of heating power. This design achieves precise temperature control of ±1℃ for each temperature zone, providing a crucial guarantee for the repeatability of material growth.

[0016] In the furnace tube compartment, a gas equalization plate is installed between the growth zone and the raw material heating zone.

[0017] The gas equalization plate includes a circular gas equalization plate body with several air holes distributed on it. The gas equalization plate is designed with multiple precision air holes, which can perform secondary beam splitting and flow equalization when the airflow from the raw material boat passes through it, ensuring that the gaseous precursor can flow evenly and vertically to the entire substrate surface, fundamentally improving the problem of uneven nucleation and growth caused by random diffusion of the precursor.

[0018] The tubular furnace also includes a frame for fixing the tubular furnace, a mechanical pump connected to the raw material compartment, baffle valves and a pressure gauge respectively located between the furnace tube compartment and the raw material compartment.

[0019] The method of using the tubular furnace of the present invention is as follows:

[0020] The precursor material is placed in the raw material boat, and the wafer substrate is placed in the substrate placement arm. The furnace tube is closed at both ends, and the substrate and raw material are transported to the center of the temperature zone through the substrate lifting system and the raw material boat lifting system. The carrier gas flows into the furnace tube through the bundled gas hose, heating the electrocoupler wire assembly. After its temperature rises to the set temperature, the gaseous precursor and carrier gas generated by the reaction act on the substrate through the gas equalization plate, and the carrier gas flows out from the first mixing chamber flange. After the set reaction time ends, the substrate lifting system rises to the top of the furnace tube chamber and cools down, and the raw material boat lifting system descends to below the baffle valve and inserts the baffle valve to rapidly cool the precursor and prevent the volatilization of secondary substances. After the reactants, substrate and furnace tube chamber have cooled to a certain temperature, the top of the furnace tube chamber is opened to take out the sample, and the observation window is opened to replace the precursor material, ready for the next use.

[0021] Beneficial Effects: Compared with existing technologies, this invention has the following significant advantages: The device has a vertical structure, with the substrate lifting system and the raw material boat lifting system arranged separately vertically. Uniform gas distribution and rectification are achieved through a multi-gas channel raw material boat and a gas equalization plate. Rapid start-up and shutdown of the reaction are achieved through an insert-type baffle valve and a dynamic sealing structure. High-precision temperature field control is achieved through a non-circular multi-temperature zone heating structure and dual thermocouple closed-loop temperature control. The device can significantly improve wafer-level deposition uniformity and process repeatability, and is suitable for large-area fabrication of two-dimensional and three-dimensional semiconductor materials. Specifically, the baffle valve, substrate lifting system, and raw material boat lifting system facilitate timely stopping of the reaction, preventing intermediate contamination of the sample; the design of the gas equalization plate and multi-channel raw material boat promotes uniform sample growth; and the dense substrate holder on the substrate placement arm allows for more flexible sample placement and increases adjustability. Attached Figure Description

[0022] Figure 1 Schematic diagram of a tubular furnace structure Figure 1 .

[0023] Figure 2 This is a schematic diagram of the structure of the furnace tube compartment and the raw material compartment in a tubular furnace.

[0024] Figure 3 This is a schematic diagram of the internal structure of the growth zone.

[0025] Figure 4 This is a schematic diagram of the raw material compartment.

[0026] Figure 5 This is a schematic diagram of the gas distribution plate.

[0027] Figure 6 Schematic diagram of a tubular furnace structure Figure 2 .

[0028] Figure 7 A schematic diagram of a system for preparing large-area, highly uniform materials.

[0029] Figure 8 The diagram shows the working process of the furnace tube compartment and the raw material compartment in a tubular furnace. a is the substrate replacement state diagram, b is the reaction state diagram, and c is the reaction stop state diagram.

[0030] Figure reference numerals: 100, furnace tube chamber; 110, growth zone; 111, molybdenum sheet partition; 112, substrate placement arm; 113, substrate drag; 114, slot; 120, raw material heating zone; 200, raw material chamber; 210, raw material boat; 211, raw material container; 212, gas channel; 213, perforated heat insulation column; 220, observation window; 300, substrate lifting system; 310, rotary motor; 320, first lead screw and nut lifting mechanism; 3 30. First infrared sensor limiter; 400. Raw material boat lifting system; 410. Second lead screw and nut lifting mechanism; 420. Bellows; 500. Heating electrocoupler assembly; 510. First heating electrocoupler; 520. Second heating electrocoupler; 600. Gas distribution plate; 610. Gas distribution plate body; 620. Air hole; 700. Baffle valve; 800. Air pressure pointer; 900. Frame; 10. Ladder; 11. Integrated control center; 12. Mechanical pump. Detailed Implementation

[0031] To further clarify the objectives, technical solutions, and advantages of this invention, the technical solutions in the embodiments of this invention will be further described below with reference to the accompanying drawings. The described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the protection scope of this invention.

[0032] Currently, vacuum tube furnaces remain the most widely used manufacturing technology for material preparation. However, they still cannot achieve controllable movement of precursors and substrates for industrial applications, thus failing to fundamentally solve the problem of precursor volatiles contaminating the chamber and the prepared material during temperature changes. This not only affects manufacturing repeatability but also further impacts material quality. Furthermore, existing automated equipment struggles to adapt to different wafer sizes, hindering more uniform material growth. This non-uniformity stems from uneven distribution of precursors, carrier gases, and other components.

[0033] This embodiment provides a multi-temperature zone tube furnace apparatus for the preparation of large-area, highly uniform materials. The following will describe its application in conjunction with... Figures 1 to 8The following describes embodiments of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, this embodiment of the invention provides a tubular furnace, including a furnace tube compartment 100, a raw material compartment 200, a substrate lifting system 300, a raw material boat lifting system 400, a heating electrocoupling wire assembly 500, a gas equalization plate 600, a baffle valve 700, and a pressure pointer 800. The furnace tube compartment 100 is connected to the raw material compartment 200. The substrate lifting system 300 is connected to the substrate within the furnace tube compartment 100 and is used to lift the substrate within the furnace tube compartment 100. The raw material boat lifting system 400 is connected to the raw material boat within the raw material compartment 200 and is used to lift the raw material boat within the raw material compartment 200. The heating electrocoupling wire assembly 500 is attached to the outer surface of the furnace tube compartment 100 and is used to provide a heat source. The baffle valve 700 is located between the furnace tube compartment 100 and the raw material compartment 200. The baffle valve 700 is an insertion type baffle valve used to connect or disconnect the furnace tube compartment 100 and the raw material compartment 200 according to the reaction progress of the tubular furnace. A pressure gauge 800 is located between the furnace tube compartment 100 and the raw material compartment 200, above the baffle valve 700, and is used to detect the pressure inside the furnace tube compartment 100. A raw material boat 210 is located inside the raw material compartment 200, and an observation window 220 is located outside the raw material compartment 200 for replacing the raw material inside. The heating electrocoupler wire assembly 500 consists of a first heating electrocoupler wire 510, a second heating electrocoupler wire 520, a thermocouple, and a heat insulation layer. The first heating electrocoupler wire 510 is attached to the outer surface of the growth zone 110, and the second heating electrocoupler wire 520 is attached to the outer surface of the raw material heating zone 120. The first and second heating electrocoupler wires 510 and 520 respectively contain thermocouples for temperature control, and the heat insulation layer is located on the outer surfaces of the first and second heating electrocoupler wires 510 and 520. Both the substrate lifting system 300 and the raw material boat lifting system 400 adopt a lead screw and nut lifting mechanism, i.e., the lead screw rotates and the nut moves linearly. This lead screw and nut lifting mechanism adopts an existing conventional design.

[0036] like Figure 2 As shown, the furnace tube compartment 100 is divided into a growth zone 110 and a raw material heating zone 120. Both the growth zone 110 and the raw material heating zone 120 are cylindrical tubes, with the diameter of the growth zone 110 being larger than that of the raw material heating zone 120. A gas distribution plate 600 is located between the growth zone 110 and the raw material heating zone 120. The furnace tube compartment 100 adopts a design with different diameters at the top and bottom; the lower raw material heating zone 120 has a smaller diameter, while the upper growth zone 110 has a larger diameter. A heating electrocoupler wire assembly 500 covers the furnace tube compartment 100 and employs a dual thermocouple design to achieve high-precision independent temperature control within ±1℃ for each temperature zone.

[0037] Preferably, to meet the high-temperature requirements of the raw material heating zone, a narrower furnace tube diameter and heating sleeve cavity internal dimensions are designed to meet the heat preservation requirements; to meet the requirements of large-size growth, the substrate area is designed with a larger furnace tube diameter and heating sleeve cavity internal dimensions; the heating sleeve cavity adopts a dual thermocouple design, which can simultaneously meet the requirements of temperature measurement and temperature control, and achieve high-precision temperature control.

[0038] like Figure 3 As shown, the growth region 110 is provided with a molybdenum sheet partition 111, a substrate placement arm 112, a substrate drag 113, and a slot 114. The molybdenum sheet partition 111 is located at the top of the substrate placement arm 112 and is used to seal the top of the furnace tube chamber 100. Several slots 114 are formed on the substrate placement arm 112 and are used to install the substrate drag 113.

[0039] The substrate placement arm 112 is provided with multiple rows of slots 114 for adapting to and supporting wafer substrates of different sizes. The installation position of the substrate drag 113 is set according to experimental needs, that is, a suitable slot 114 is selected for installing and fixing the substrate drag 113, thereby achieving precise positioning of the substrate.

[0040] Preferably, in this embodiment, the multi-opening slot design allows the substrate to be placed at various cross-sectional positions in the growth region 110, and high-precision positioning can be achieved in conjunction with the substrate lifting system 300; the tube furnace in this embodiment can achieve material preparation at temperatures up to 1200°C, and the substrate placement arm is made of high-temperature resistant quartz or corundum material; it is equipped with multi-size wafer trolleys that can be inserted into the slots to meet different substrate size requirements.

[0041] like Figure 4 As shown, the raw material boat 210 includes a raw material container 211 for holding solid or liquid precursors, a gas channel 212, and a perforated insulating column 213. The gas channel 212 passes through the bottom of the raw material container 211 and is connected to it. The perforated insulating column 213 surrounds the gas channel 212. The perforated insulating column 213 is a hollow column filled with an insulating medium, preferably insulating cotton or porous alumina. The gas channel 212 has multiple independent gas flow channels inside. The upper end of the gas channel extends out and penetrates the bottom surface of the raw material container 211, and the lower end of the gas channel is airtightly coupled to a mixing chamber flange (not shown in the figure).

[0042] In this embodiment, the raw material is placed in the raw material holding dish 211, and multiple discrete gas channels pass through the raw material holding dish 211. After the raw material is evaporated into a gaseous state at high temperature, it can flow evenly onto the substrate through the multiple gas channels.

[0043] A first mixing chamber flange is installed at the upper end of the furnace tube compartment 100, and a second mixing chamber flange is installed at the lower end of the raw material compartment 200. The first mixing chamber flange is connected to one inlet pipe and one outlet pipe, and the second mixing chamber flange is also connected to one inlet pipe and one outlet pipe. Therefore, the tubular furnace has a total of two inlet pipes and two outlet pipes. The two inlet pipes are connected to external gas cylinders, and the two outlet pipes are tail gas pipes. Specifically, the inlet ends of the first and second mixing chamber flanges are connected to external gas cylinders, and the outlet ends of the first and second mixing chamber flanges are connected to tail gas pipes. The tail gas pipes are used to collect waste gas containing various impurities carried by the carrier gas through the entire system. The inlet pipe of the second mixing chamber flange is also connected to a gas pump.

[0044] As a supporting device for the mixing chamber flange, this embodiment includes a bundled gas hose, which connects the gas cylinder to the external gas cylinder and the mixing chamber flange. In this embodiment, the upper end of the tubular furnace is the upper end of the furnace tube compartment 100, and it has an inlet pipe. The lower end of the tubular furnace is the lower end of the raw material compartment 200, and it also has an inlet pipe. The airflow direction is controlled by opening and closing the two inlet pipes. Specifically, one end of the bundled gas hose is connected to the gas cylinder, and the other end is connected to the raw material compartment 200 or the furnace tube compartment 100 via the mixing chamber flange. The bundled gas hose enables inlet and outlet gas flow and mode switching, satisfying the airflow direction switching requirements at different stages of material growth and use. The bundled gas hose is connected to a CNC system and an integrated flow meter system, enabling multi-channel, high-precision airflow control to meet the operation and switching requirements of various carrier gases.

[0045] like Figure 5 As shown, the gas equalization plate 600 includes a circular gas equalization plate body 610, on which a plurality of air holes 620 are distributed. The gas equalization plate 600 is horizontally disposed in the middle of the furnace tube, between the growth zone 110 and the raw material heating zone 120. The gas equalization plate body 610 is provided with an array of precision air holes optimized by fluid simulation, which are used to perform secondary flow equalization on the rising airflow. The gas equalization plate body 610 is provided with multiple air holes, which can further even out the distribution of gaseous precursors and airflow when they pass through, so as to make them flow uniformly towards the substrate.

[0046] like Figure 1-5As shown, the substrate lifting system 300 includes a first lead screw and nut lifting mechanism 320 and a rotary motor 310. The nut of the first lead screw and nut lifting mechanism 320 is connected to the substrate placement arm 112 and is used to drive the substrate placement arm 112 to move up and down. The rotary motor 310 is connected to the substrate placement arm 112 and is used to drive the substrate placement arm 112 to rotate. When the substrate lifting system 300 is started, the lead screw in the first lead screw and nut lifting mechanism 320 rotates, driving the nut to move linearly. The nut drives the substrate placement arm 112 to move, and the rotary motor 310 rotates the substrate placement arm 112, thereby realizing the rotational lifting or lowering of the substrate placement arm 112.

[0047] The first lead screw and nut lifting mechanism 320 drives the substrate placement arm 112 to achieve precise vertical displacement, and the rotary motor 310 can link the substrate placement arm 112 to achieve uniform rotation within and outside the growth region 110. The first infrared sensor limiter 330 is used for position closed-loop feedback.

[0048] The raw material boat lifting system 400 includes a second lead screw and nut lifting mechanism 410 and a bellows 420. The nut of the second lead screw and nut lifting mechanism 410 is connected to the bellows 420, and the bellows 420 is connected to the raw material boat 210. When the lead screw in the second lead screw and nut lifting mechanism 410 rotates, the nut can move linearly back and forth, driving the bellows 420 to compress or expand. When the bellows 420 is compressed, the raw material boat 210 rises; when the bellows 420 is expanded, the raw material boat 210 falls.

[0049] The second infrared sensor limiter is connected to the second lead screw and nut lifting mechanism 410. A compressible bellows 420 is used to maintain the system's airtightness during lifting, and the airtight bellows design enables long-distance movement of the raw material boat. The raw material container 211 in the raw material boat 210 is installed above the bellows, and a perforated heat-insulating column 213 and part of the gas passage 212 are installed inside the bellows.

[0050] When the raw material boat lifting system 400 is started, the second screw nut lifting mechanism 410 drives the raw material boat 210 to rise or fall. When the raw material boat 210 rises, the bellows 420 is compressed, and the raw material boat 210 can move from the raw material compartment 200 to the raw material heating zone 120.

[0051] This embodiment provides a method for using a tube furnace. Precursor material is placed in the raw material boat 210, and the wafer substrate is placed in the substrate placement arm 112. Both ends of the furnace tube are closed. The substrate and raw material are transported to the center of the temperature zone via the substrate lifting system 300 and the raw material boat lifting system 400. Carrier gas flows into the furnace tube through a bundled gas hose, heating the electrocoupler wire assembly 500. After its temperature rises to the set temperature, the gaseous precursor and carrier gas generated by the reaction act on the substrate through the gas equalization plate 600. The carrier gas flows out from the first mixing chamber flange. After the set reaction time ends, the substrate lifting system 300 rises to the upper end of the furnace tube chamber 100 and cools, while the raw material boat lifting system 400 descends below the baffle valve 700 and inserts into the baffle valve 700, allowing the precursor to cool rapidly and preventing the volatilization of secondary substances. After the reactants, substrate, and furnace tube chamber 100 cool to a certain temperature, the upper end of the furnace tube chamber 100 is opened to remove the sample. The observation window 220 is opened to replace the precursor material, ready for the next use.

[0052] Example 2

[0053] like Figure 6 As shown, this embodiment of the invention provides a tubular furnace, including a furnace tube compartment 100, a raw material compartment 200, a substrate lifting system 300, a raw material boat lifting system 400, a heating electrocoupling wire assembly 500, a gas equalization plate 600, a baffle valve 700, a pressure gauge 800, and a frame 900. The furnace tube compartment 100 is connected to the raw material compartment 200. The substrate lifting system 300 is connected to the substrate within the furnace tube compartment 100 and is used to lift the substrate within the furnace tube compartment 100. The raw material boat lifting system 400 is connected to the raw material boat within the raw material compartment 200 and is used to lift the raw material boat within the raw material compartment 200. The heating electrocoupling wire assembly 500 is attached to the outer surface of the furnace tube compartment 100 and is used to provide a heat source. The baffle valve 700 is located between the furnace tube compartment 100 and the raw material compartment 200. The baffle valve 700 is an insertion type baffle valve used to connect or disconnect the furnace tube compartment 100 and the raw material compartment 200 according to the reaction progress of the tubular furnace. A pressure gauge 800 is located between the furnace tube compartment 100 and the raw material compartment 200, and above the baffle valve 700, to detect the pressure inside the furnace tube compartment 100. A frame 900 supports the tube furnace. The first upper plate of the substrate lifting system 300 is fixed to the top surface of the frame 900, and the second lower plate of the raw material boat lifting system 400 is fixed to the bottom surface of the frame 900.

[0054] Specifically, the furnace tube compartment 100, raw material compartment 200, substrate lifting system 300, raw material boat lifting system 400, heating electric coupler wire group 500, gas equalization plate 600, baffle valve 700 and gas pressure pointer 800 are set up in the same way as in Example 1.

[0055] Example 3

[0056] like Figure 7As shown, this embodiment of the invention provides a tubular furnace, including a furnace tube compartment 100, a raw material compartment 200, a substrate lifting system 300, a raw material boat lifting system 400, a heating electrocoupling wire assembly 500, a gas equalization plate 600, a baffle valve 700, a gas pressure pointer 800, a frame 900, a ladder 10, an integrated control center 11, and a mechanical pump 12. The mechanical pump 12 is connected to the gas channel in the raw material compartment 200 via a mixing chamber flange. The ladder 10 is located next to the frame 900 and is used by the operator to operate the tubular furnace. The integrated control center 11 is connected to the various electrical components within the tubular furnace and is used to control the start-up and shutdown of these components. Specifically, the integrated control center 11 is connected to the rotary motor 310, the first lead screw and nut lifting mechanism 320, and the first infrared sensor limiter 330 in the substrate lifting system 300, the second lead screw and nut lifting mechanism 410 and the second infrared sensor limiter in the raw material boat lifting system 400, and the heating electric coupler group 500, respectively, to realize full-process numerical control and collaboration. The integrated control center 11 can also be connected to the mechanical pump 12 and the ladder 10.

[0057] The integrated control center 11 is connected to the bundled gas hose and integrated flow meter system, enabling the programming and switching of multi-channel airflow modes. It not only supports a single carrier gas mode, but also allows for the sequential switching or mixing ratio control of different carrier gases, meeting the preparation needs of complex material systems such as heterojunctions and gradient composition materials.

[0058] Among them, the tube furnace is designed vertically. The vertical structure can effectively avoid the uneven natural convection caused by gravity in the horizontal tube furnace, creating an ideal flow field environment for achieving uniform material synthesis within the substrate cross section.

[0059] The substrate lifting system 300 and substrate placement arm 112 are located at the upper end, while the raw material boat 210 and raw material boat lifting system 400 are located at the lower end. The furnace tube chamber 100 and raw material chamber 200 constitute the furnace tube. The upper end of the furnace tube is connected to the substrate lifting system 300, and the lower end is connected to the raw material boat lifting system 400. Both ends are sealed with rubber rings to the lifting system. The substrate and raw material can be numerically controlled and kept airtight through a mechanical linkage device to prevent air from entering the furnace tube. The designed raw material boat 210 with multiple gas channels can achieve uniform flow of multi-channel airflow. After passing through the gas equalization plate 600, it can further divide the precursor and airflow, achieving uniform growth of materials on a large-area substrate. This invention has good airtightness, numerically controlled feeding and discharging, and can achieve uniform flow of airflow and precursor materials, avoiding uneven airflow distribution.

[0060] Specifically, the furnace tube compartment 100, raw material compartment 200, substrate lifting system 300, raw material boat lifting system 400, heating electric coupler wire group 500, gas equalization plate 600, baffle valve 700 and gas pressure pointer 800 are set in the same way as in Example 1.

[0061] In this embodiment, the substrate and raw materials can be numerically controlled to move up and down within the furnace tube via the linkage of the substrate lifting system 300 and the raw material boat lifting system 400, respectively. Before and during the reaction, the substrate is installed in the substrate carrier and moved to the center of the growth zone 110 under the traction of the substrate lifting system 300. The raw material boat 210 is moved to the center of the raw material heating zone 120 under the traction of the raw material boat lifting system 400. At the end of the reaction, the substrate lifting system 300 raises the substrate to the outside of the temperature zone for cooling, stopping the reaction. At the end of the reaction, the raw material boat lifting system 400 lowers the raw material boat 210 to the raw material chamber 200 for rapid cooling and inserts a baffle valve 700 to isolate the furnace tube chamber 100 and the raw material chamber 200, preventing the overflow of secondary thermal decomposition products and avoiding most of the contamination from the raw materials.

[0062] In this embodiment, the substrate lifting system 300 and the raw material boat lifting system 400 are fixed in a frame 900, which is a stainless steel support. The substrate lifting system 300 and the raw material boat lifting system 400 are connected to the outside through sealing rings, which can effectively achieve a gas-tight effect. Since the designed tube furnace can prepare materials up to 1200°C, all internal components of the furnace tube are made of high-temperature resistant materials, such as the lifting system, which is made of molybdenum metal and high-temperature resistant stainless steel.

[0063] Preferably, for material preparation or sintering at temperatures exceeding 1000°C, water-cooling equipment can be selectively used. This prevents the sealing ring from softening and affecting the airtightness, and further accelerates the cooling of the substrate and precursor, achieving precursor cooling in a shorter time. Preferably, both the upper and lower interfaces of the tube furnace are water-cooled, with cooling water positioned near the sealing ring, enabling real-time water cooling to ensure the airtightness of the sealing ring and meet the equipment's airtightness requirements. The upper end of the tube furnace refers to the upper end of the furnace tube compartment 100, and the lower end of the tube furnace refers to the lower end of the raw material compartment 200.

[0064] Example 4

[0065] like Figure 8 As shown, this embodiment of the invention provides a method for using a tubular furnace, including the following steps:

[0066] like Figure 8 As shown in Figure a, after the equipment completes the previous growth cycle, the substrate lifting system is first controlled to raise the substrate placement arm 112 from the growth region 110. During the raising process, the upper flange of the equipment (the first mixing chamber flange) and the molybdenum sheet partition 111 are opened, and the substrate placement arm 112 is continuously raised until it is removed from the equipment, and the grown sample is taken out (the movable range of the substrate placement arm is as shown in Figure a). Figure 8 (as shown in a).

[0067] To initiate a new growth cycle, a new substrate is inserted into the slot of the substrate placement arm. Preferably, during multiple growth cycles, different positions within the densely packed slots can be selected for substrate placement (the substrate placement range is as follows). Figure 8 (as shown in b), so as to optimize process parameters by combining the growth state at different locations, thereby obtaining higher quality samples.

[0068] like Figure 8 As shown in Figure b, after the substrate loading is completed, the raw material boat lifting system is controlled to lower the substrate placement arm 112 to a preset fixed position. Once lowered to the appropriate position, the molybdenum sheet partition 111 is installed onto the top of the substrate placement arm 112, and the upper flange of the equipment is tightened to ensure the airtightness of the tubular furnace cavity. Subsequently, the airtight observation window is opened and the precursor is replaced; after replacement, the observation window is closed, and the insertion baffle valve is opened to control the raw material boat lifting system to rise to a preset fixed position (the movable range of the raw material boat is as follows). Figure 8 (as shown in c).

[0069] To improve process adjustment flexibility, the relative distance between the raw material boat 210 and the substrate drag 113 can be adjusted by replacing the quartz raw material boat 210 with different heights (the raw material placement range is as follows). Figure 8 As shown in the figure, this enables precise control of precursor vapor concentration and reaction atmosphere uniformity; at the same time, combined with chamber temperature control, it can achieve fine matching of temperature gradient, further improving the crystallization quality and composition uniformity of the film.

[0070] After completing the above mechanical positioning and sealing operations, the mechanical vacuum pump can be selectively started to pump the pressure inside the cavity to 10. -3 The pressure is in the Pa range; then high-purity argon gas is introduced to atmospheric pressure, and the "vacuuming-argon filling" replacement operation is repeated 1 to 3 times to fully remove residual impurity gases in the cavity.

[0071] The heating program is then initiated, and the tube furnace is heated to the target reaction temperature according to the preset temperature rise curve. Since the growth zone 110 and the raw material heating zone 120 operate at different temperatures, they are preferably set and controlled independently. After reaching the target temperature, the temperature is maintained at a constant level for approximately 5 minutes to allow the precursor to enter a stable evaporation state. At this time, the precursor vapor is carried by the carrier gas and blown from the substrate direction towards the raw material boat.

[0072] After the temperature stabilizes, the airflow direction is switched so that the airflow blows from the direction of the raw material boat to the direction of the substrate (i.e., reverse airflow mode) to increase the residence time and adsorption probability of the precursor vapor on the substrate surface. The gas distribution plate 600 set in the gas path is used to uniformly disperse the mixed airflow of carrier gas and precursor vapor; its porous structure can effectively suppress turbulence and reduce the velocity gradient, thereby obtaining a more uniform vapor flux in various areas of the substrate surface, thereby improving the film thickness and spatial uniformity of composition.

[0073] The above growth stages are maintained for a preset time to complete material growth. The specific duration can be set according to the target film thickness and growth rate, preferably 10 to 60 minutes.

[0074] like Figure 8 As shown in Figure c, after growth is complete, the heating program is immediately stopped, and the substrate placement arm is raised to the initial safe height (corresponding to...). Figure 8 The highest slot in a); simultaneously control the raw material boat to descend to the initial standby position (corresponding to Figure 8 (the lowest limit point in c), and close the baffle valve. Then close the argon inlet valve and turn on the mechanical vacuum pump to evacuate the chamber to 10. -3 The pressure is in the Pa range, and then high-purity argon gas is introduced to atmospheric pressure to cool the cavity. After cooling to room temperature, one growth cycle is completed.

Claims

1. A multi-temperature zone tubular furnace, characterized in that, The system includes a furnace tube compartment containing a substrate placement arm and an outer heating electrocoupling wire assembly. The furnace tube compartment is divided into a growth zone and a raw material heating zone. A raw material compartment is connected to the furnace tube compartment and contains a raw material boat. A substrate lifting system is connected to the substrate placement arm within the furnace tube compartment and is used to raise and lower the substrate placement arm, allowing the substrate to move within the growth zone. A raw material boat lifting system is connected to the raw material boat within the raw material compartment and is used to raise and lower the raw material boat. The raw material boat moves within a channel formed by the raw material heating zone and the raw material compartment, driven by the raw material boat lifting system.

2. The multi-zone tubular furnace according to claim 1, characterized in that, In the furnace tube compartment, both the growth zone and the raw material heating zone are cylindrical tubes, with the diameter of the tube in the growth zone being larger than that in the raw material heating zone.

3. The multi-temperature zone tubular furnace according to claim 1, characterized in that, The growth area is equipped with a substrate placement arm, and the top of the substrate placement arm is equipped with a molybdenum sheet partition. The molybdenum sheet partition is used to seal the furnace tube chamber. The substrate placement arm is equipped with several slots for installing substrate trolleys.

4. The multi-zone tubular furnace according to claim 1, characterized in that, The substrate lifting system includes a first lead screw and nut lifting mechanism and a rotary motor. The nut of the first lead screw and nut lifting mechanism is connected to the substrate placement arm and is used to drive the substrate placement arm to lift. The rotary motor is connected to the substrate placement arm and is used to drive the substrate placement arm to rotate.

5. The multi-zone tubular furnace according to claim 1, characterized in that, The raw material boat lifting system includes a second lead screw and nut lifting mechanism and a bellows. The nut of the second lead screw and nut lifting mechanism is connected to the bellows, and the bellows is connected to the raw material boat. The second lead screw and nut lifting mechanism is used to lift the raw material boat.

6. The multi-zone tubular furnace according to claim 1, characterized in that, The raw material boat includes a raw material container, a gas channel, and a perforated heat insulation column. The gas channel runs through the bottom of the raw material container and is connected to it. The perforated heat insulation column surrounds the gas channel.

7. The multi-zone tubular furnace according to claim 1, characterized in that, The heating electrocoupler assembly consists of a first heating electrocoupler wire and a second heating electrocoupler wire, wherein the first heating electrocoupler wire is attached to the outer surface of the growth zone, and the second heating electrocoupler wire is attached to the outer surface of the raw material heating zone.

8. The multi-zone tubular furnace according to claim 1, characterized in that, In the furnace tube compartment, a gas equalization plate is installed between the growth zone and the raw material heating zone.

9. The multi-zone tubular furnace according to claim 7, characterized in that, The gas equalization plate includes a circular gas equalization plate body, on which a number of air holes are distributed.

10. The multi-zone tubular furnace according to claim 1, characterized in that, It also includes a frame for fixing the tubular furnace, a mechanical pump connected to the feed tank, baffle valves and pressure gauges located between the furnace tube compartment and the feed tank respectively.

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