Polycrystalline zinc sulfide chemical vapor deposition system and method

Abstract

A polycrystalline zinc sulfide chemical vapor deposition system and method are provided. The polycrystalline zinc sulfide chemical vapor deposition system includes a chemical vapor deposition furnace, a sulfur melting device, a zinc melting device, a gas supply device, a first pipe, a second pipe, and an extraction device. The chemical vapor deposition furnace includes a furnace body, a deposition chamber, and a heater. The furnace body has through holes that can be opened and closed. The deposition chamber is located inside the furnace body and has perforations at the top. The heater is located inside the furnace body and around the deposition chamber, and is used to heat the deposition chamber. The sulfur melting device is located outside the chemical vapor deposition furnace. The zinc melting device is located outside the chemical vapor deposition furnace. The gas supply device is located outside the chemical vapor deposition furnace. The first pipe connects the sulfur melting device and the deposition chamber. The second pipe connects the zinc melting device and the deposition chamber. The deposition chamber is used for the chemical vapor deposition of zinc vapor and sulfur vapor. The extraction device includes a connecting pipe, a connecting pipe through hole, and a perforation, and is connected to the deposition chamber via the connecting pipe.

Description

Technical Field

[0001] This disclosure relates to the field of zinc sulfide materials, and more specifically to a polycrystalline zinc sulfide chemical vapor deposition system and method. Background Technology

[0002] Zinc sulfide exhibits good transmittance and mechanical properties in the 8-12 μm range and is widely used in infrared guidance, fairings, and other fields. Currently, chamber chemical vapor deposition (CVD) is considered the best process for preparing zinc sulfide.

[0003] Chinese invention patent application publication number CN108165951A, published on June 15, 2018, discloses a preparation equipment for zinc sulfide or zinc selenide shrouds, which uses a reaction system of zinc and hydrogen sulfide. Because this system involves the use of toxic hydrogen sulfide gas, the production process is highly dangerous and requires high-level system design for environmental treatment and gas supply treatment.

[0004] Furthermore, in this preparation equipment, the crucible containing the solid zinc source is located below the deposition chamber, and both the deposition chamber and the crucible are located inside the chemical vapor deposition furnace. This layout restricts the crucible and, consequently, the deposition in the deposition chamber, which is not conducive to improving the preparation capacity of a single chemical vapor deposition furnace.

[0005] Furthermore, in this preparation equipment, both the deposition chamber and the crucible are located inside the chemical vapor deposition furnace. Both the deposition chamber and the crucible are equipped with their own heaters. The heat generated by the heater of the lower crucible will interfere with the temperature field of the upper deposition chamber, thereby affecting the uniformity of the temperature field of the deposition chamber. Summary of the Invention

[0006] In view of the problems existing in the background art, one object of this disclosure is to provide a polycrystalline zinc sulfide chemical vapor deposition system and method, which can avoid the problem of toxic hydrogen sulfide involved in the preparation of zinc sulfide by the reaction system of zinc and hydrogen sulfide, thereby reducing the danger in the production process.

[0007] Another objective of this disclosure is to provide a polycrystalline zinc sulfide chemical vapor deposition system and method, which can overcome the limitation of the raw materials for preparing zinc sulfide by the structure of a single chemical vapor deposition furnace, thereby improving the deposition in the deposition chamber inside the chemical vapor deposition furnace and increasing the preparation capacity of a single chemical vapor deposition furnace.

[0008] Another object of this disclosure is to provide a polycrystalline zinc sulfide chemical vapor deposition system and method that can avoid the influence of heating of the zinc source on the temperature field of the deposition chamber, thereby improving the uniformity of the temperature field of the deposition chamber.

[0009] Therefore, a polycrystalline zinc sulfide chemical vapor deposition system includes a chemical vapor deposition furnace, a sulfur melting device, a zinc melting device, a gas supply device, a first pipe, a second pipe, and a gas extraction device. The chemical vapor deposition furnace includes a furnace body, a deposition chamber, and a heater. The furnace body forms a three-dimensional closed structure and has a through hole at the top, allowing the furnace body to be opened and closed. The deposition chamber is located inside the furnace body and has a perforation at the top. The heater is located inside the furnace body and around the deposition chamber, and is used to heat the deposition chamber from outside the deposition chamber. The sulfur melting device is located outside the chemical vapor deposition furnace and is used to hold sulfur and heat it to evaporate it into sulfur vapor. The zinc melting device is located outside the chemical vapor deposition furnace and is used to hold zinc and heat it to evaporate it into zinc vapor. The gas supply device... The apparatus is located outside the furnace body of the chemical vapor deposition furnace. A gas supply system supplies argon and hydrogen to the sulfur melting unit and argon to the zinc melting unit. A first pipe connects the sulfur melting unit and the deposition chamber to supply argon, hydrogen, and sulfur vapor from the sulfur melting unit into the deposition chamber. A second pipe connects the zinc melting unit and the deposition chamber to supply argon and zinc vapor from the zinc melting unit into the deposition chamber. The deposition chamber is used for chemical vapor deposition of the zinc vapor and sulfur vapor supplied to the deposition chamber to form polycrystalline zinc sulfide. An extraction device includes a connecting pipe that seals a through-hole passing through the furnace body and a perforation in the deposition chamber. The extraction device is connected to the deposition chamber via the connecting pipe to evacuate the deposition chamber and extract the tail gas generated during the chemical vapor deposition process of the zinc vapor and sulfur vapor.

[0010] A polycrystalline zinc sulfide chemical vapor deposition method employs the aforementioned polycrystalline zinc sulfide chemical vapor deposition system. The method includes the following steps: placing high-purity sulfur into a sulfur melting device; controlling the temperature of the sulfur melting device at 150-250℃ and the vacuum degree at 4000-8000 Pa; placing high-purity zinc ingots into a zinc melting device; controlling the temperature of the zinc melting device at 550-650℃ and the vacuum degree at 3000-6000 Pa; and controlling the ratio of hydrogen to sulfur evaporation in the sulfur melting device supplied by a gas supply device at 1.5-2. The volume ratio of argon to sulfur vapor in the sulfur melting unit is controlled at 15-30; the volume ratio of argon supplied to the zinc melting unit to the amount of zinc vapor evaporation is controlled at 10-20; sulfur vapor, hydrogen, and argon are supplied to the deposition chamber through the first pipeline, and zinc vapor and argon are supplied to the deposition chamber through the second pipeline. The zinc vapor and sulfur vapor supplied to the deposition chamber are chemically vapor-deposited to form polycrystalline zinc sulfide. The temperature of the deposition chamber is controlled at 620℃-700℃, and the pressure is controlled at 3000-6000Pa. During the reaction in the deposition chamber, the volume ratio of zinc vapor to sulfur vapor is controlled at 0.7-0.9.

[0011] The beneficial effects of this disclosure are as follows.

[0012] In the polycrystalline zinc sulfide chemical vapor deposition system and method disclosed herein, sulfur vapor is generated by a sulfur melting device, zinc vapor is generated by a zinc melting device, argon and hydrogen are supplied to the sulfur melting device and the zinc melting device by a gas supply device, argon, hydrogen and sulfur vapor from the sulfur melting device are supplied to the deposition chamber through a first pipe, and argon and zinc vapor from the zinc melting device are supplied to the deposition chamber through a second pipe. The zinc vapor and sulfur vapor supplied to the deposition chamber are then chemically vapor deposited to form polycrystalline zinc sulfide. This avoids the problem of toxic hydrogen sulfide involved in the zinc and hydrogen sulfide reaction system for preparing zinc sulfide in the prior art, thereby reducing the danger in the production process and reducing the system design requirements for environmental treatment and gas supply treatment.

[0013] Compared to the prior art where the crucible holding the solid zinc source is located inside the chemical vapor deposition (CVD) furnace, in the polycrystalline zinc sulfide CVD system and method disclosed herein, since the deposition chamber is located inside the CVD furnace while the sulfur melting device for forming sulfur vapor and the zinc melting device for forming zinc vapor are located outside the CVD furnace, the sulfur melting device and the zinc melting device for forming zinc vapor are no longer limited by the CVD furnace body. This improves the deposition efficiency in the deposition chamber inside the CVD furnace, increasing the production capacity and flexibility of a single CVD furnace. Furthermore, since both the sulfur melting device and the zinc melting device are located outside the CVD furnace, it is convenient to inspect the sulfur melting device and the zinc melting device in real time while the CVD furnace is operating, allowing for flexible placement of these devices outside the furnace. Furthermore, the sulfur melting device that forms sulfur vapor and the zinc melting device that forms zinc vapor, located outside the chemical vapor deposition furnace, only need to be connected through the first and second pipes, respectively. In other words, the sulfur melting device, the zinc melting device, and the chemical vapor deposition furnace can be designed and assembled as three independent modules, which greatly simplifies the design and improves the convenience of operation.

[0014] Compared with the prior art where the crucible holding the solid zinc source is located inside the chemical vapor deposition furnace, in the polycrystalline zinc sulfide chemical vapor deposition system and method disclosed herein, since the deposition chamber is located inside the chemical vapor deposition furnace and the zinc melting device that forms zinc vapor is located outside the chemical vapor deposition furnace, the influence of heating of the zinc melting device on the temperature field of the deposition chamber can be avoided, thereby improving the uniformity of the temperature field of the deposition chamber. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a polycrystalline zinc sulfide chemical vapor deposition system according to the present disclosure.

[0016] Figure 2 yes Figure 1 Enlarged view of part of the structure.

[0017] Figure 3 This is a top view schematic diagram of an example deposition chamber of a polycrystalline zinc sulfide chemical vapor deposition system.

[0018] Figure 4 This is a top view schematic diagram of another example of a deposition chamber in a polycrystalline zinc sulfide chemical vapor deposition system.

[0019] Figure 5 This is a structural diagram of the first and second pipes of a polycrystalline zinc sulfide chemical vapor deposition system.

[0020] Figure 6 This is a structural diagram of the support plate and nozzle of a polycrystalline zinc sulfide chemical vapor deposition system.

[0021] The reference numerals in the attached figures are explained as follows:

[0022] 1000 polycrystalline zinc sulfide chemical vapor deposition system 3 zinc melting unit

[0023] 1. Chemical vapor deposition furnace 31. Zinc liquid level drop detection agency

[0024] 10 Furnace body 32 Second heating mechanism

[0025] 101 Through-hole 4 Air Supply Device

[0026] 102 outer wall 5A first pipeline

[0027] 103 Cooling Jacket 5B Second Pipe

[0028] 104 insulation layer, 51 air intake pipe

[0029] 11 Deposition Chamber 52 Heating Layer

[0030] 111 Perforated 53 Insulation Jacket

[0031] 12 heaters, 54 outer casing

[0032] 13 Deposition chamber 6 extraction device

[0033] 131 through hole 61 connecting pipe

[0034] 14 Support Components 62 Dust Collection Pump

[0035] 15 movable cover 63 vacuum pump

[0036] 16-card assembly, 64-card exhaust gas treatment mechanism

[0037] 17 support rods and 7 support plates

[0038] 18 Moving mechanism 71 First airflow channel

[0039] 19 supports, 72 second airflow channels

[0040] 2. Sulfur melting unit 73 flow channel

[0041] 21. Sulfur liquid level drop detection mechanism with 8 nozzles

[0042] 22 First heating mechanism 9 Control device Detailed Implementation

[0043] The accompanying drawings illustrate embodiments of this disclosure, and it will be understood that the disclosed embodiments are merely examples of this disclosure, which can be implemented in various forms. Therefore, the specific details disclosed herein should not be construed as limiting, but are intended only as the basis for the claims and as an illustrative basis to teach those skilled in the art how to implement this disclosure in various ways.

[0044] [Polycrystalline Zinc Sulfide Chemical Vapor Deposition System]

[0045] Reference Figure 1 and Figure 2 According to the present disclosure, the polycrystalline zinc sulfide chemical vapor deposition system 1000 includes a chemical vapor deposition furnace 1, a sulfur melting device 2, a zinc melting device 3, a gas supply device 4, a first pipeline 5A, a second pipeline 5B, and a gas extraction device 6.

[0046] The chemical vapor deposition furnace 1 includes a furnace body 10, a deposition chamber 11, and a heater 12. The furnace body 10 forms a three-dimensional closed structure and has a through hole 101 at the top, allowing it to be opened and closed. The deposition chamber 11 is located inside the furnace body 10 and has a perforation 111 at the top. The heater 12 is located inside the furnace body 10 and around the deposition chamber 11, and is used to heat the deposition chamber 11 from outside. A sulfur melting device 2 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The sulfur melting device 2 is used to hold sulfur and heat it to evaporate it into sulfur vapor. A zinc melting device 3 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The zinc melting device 3 is used to hold zinc and heat it to evaporate it into zinc vapor. A gas supply device 4 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The gas supply device 4 is used to supply argon and hydrogen to the sulfur melting device 2 and to supply argon to the zinc melting device 3. The first conduit 5A connects the sulfur melting device 2 and the deposition chamber 11 to supply argon, hydrogen, and sulfur vapor from the sulfur melting device 2 into the deposition chamber 11. The second conduit 5B connects the zinc melting device 3 and the deposition chamber 11 to supply argon and zinc vapor from the zinc melting device 3 into the deposition chamber 11. The deposition chamber 11 is used for chemical vapor deposition of the zinc vapor and sulfur vapor supplied to the deposition chamber 11 to form polycrystalline zinc sulfide. The vacuum device 6 includes a connecting pipe 61 that seals through the through hole 101 of the furnace body 10 and the perforation 111 of the deposition chamber 11. The vacuum device 6 is connected to the deposition chamber 11 via the connecting pipe 61 to evacuate the deposition chamber 11 and extract the tail gas formed during the chemical vapor deposition of zinc vapor and sulfur vapor.

[0047] In the polycrystalline zinc sulfide chemical vapor deposition system 1000 disclosed herein, sulfur vapor is generated by a sulfur melting device 2, zinc vapor is generated by a zinc melting device 3, argon and hydrogen are supplied to the sulfur melting device 2 and the zinc melting device 3 by a gas supply device 4, argon, hydrogen and sulfur vapor from the sulfur melting device 2 are supplied to the deposition chamber 11 through a first pipe 5A, and argon and zinc vapor from the zinc melting device 3 are supplied to the deposition chamber 11 through a second pipe 5B. The deposition chamber 11 then performs chemical vapor deposition of the zinc vapor and sulfur vapor supplied to the deposition chamber 11 to form polycrystalline zinc sulfide. This avoids the problem of toxic hydrogen sulfide involved in the zinc and hydrogen sulfide reaction system for preparing zinc sulfide in the prior art, thereby reducing the danger in the production process and reducing the system design requirements for environmental treatment and gas supply treatment.

[0048] Compared to the prior art where the crucible holding the solid zinc source is located inside the chemical vapor deposition furnace, in the polycrystalline zinc sulfide chemical vapor deposition system 1000 of this disclosure, since the deposition chamber 11 is located inside the furnace body 10 of the chemical vapor deposition furnace 1, the sulfur melting device 2 that forms sulfur vapor is located outside the furnace body 10 of the chemical vapor deposition furnace 1, and the zinc melting device 3 that forms zinc vapor is located outside the furnace body 10 of the chemical vapor deposition furnace 1, the sulfur melting device 2 and the zinc melting device 3 that provide chemical vapor deposition reactants are no longer restricted by the furnace body 10 of the chemical vapor deposition furnace 1, thereby improving the deposition in the deposition chamber 11 inside the furnace body 10 of the chemical vapor deposition furnace 1, and improving the preparation capacity and preparation flexibility of a single chemical vapor deposition furnace 1. Furthermore, both the sulfur melting device 2, which generates sulfur vapor, and the zinc melting device 3, which generates zinc vapor, are located outside the furnace body 10 of the chemical vapor deposition furnace 1. This facilitates real-time inspection of the sulfur melting device 2 and the zinc melting device 3 while the chemical vapor deposition furnace 1 is operating, and allows for flexible installation of the sulfur melting device 2 and the zinc melting device 3 outside the furnace body 10 of the chemical vapor deposition furnace 1. Moreover, since the sulfur melting device 2 and the zinc melting device 3, located outside the furnace body 10 of the chemical vapor deposition furnace 1, only need to be connected via the first pipe 5A and the second pipe 5B respectively, the sulfur melting device 2, the zinc melting device 3, and the chemical vapor deposition furnace 1 can be designed and assembled as three independent modules, greatly simplifying the design and improving operational convenience.

[0049] Compared to the prior art where the crucibles holding the solid zinc source are all located inside the chemical vapor deposition furnace, in the polycrystalline zinc sulfide chemical vapor deposition system 1000 of this disclosure, since the deposition chamber 11 is located inside the furnace body 10 of the chemical vapor deposition furnace 1, the zinc melting device 3 that forms zinc vapor is located outside the furnace body 10 of the chemical vapor deposition furnace 1. This avoids the influence of heating of the zinc melting device 3 on the temperature field of the deposition chamber 11, thereby improving the uniformity of the temperature field of the deposition chamber 11.

[0050] like Figure 2 As shown, the furnace body 10 includes an outer wall 102, a cooling jacket 103, and an insulation layer 104. The cooling jacket 103 is located inside the outer wall 102, and a circulating cooling medium is introduced into the cooling jacket 103. The insulation layer 104 is located inside the cooling jacket 103. A through hole 101 penetrates the outer wall 102, the cooling jacket 103, and the insulation layer 104. By configuring the cooling jacket 103 and the insulation layer 104 with a circulating cooling medium, the temperature stability inside the furnace body 10 can be effectively maintained, improving the stability and quality of the zinc sulfide preparation process. The circulating cooling medium introduced into the cooling jacket 103 can be, for example, but not limited to, water. For example, the outer wall 102 is made of stainless steel; the cooling jacket 103 is made of carbon steel or stainless steel; and the insulation layer 104 is made of graphite felt.

[0051] The deposition chamber 11 can be constructed by assembling isostatically pressed graphite plates, improving the flexibility of the deposition chamber 11 in adapting to the internal space of the furnace body 10. The specific structure of the deposition chamber 11 can be as follows: Figure 3 and Figure 4 As shown, that is Figure 3 The deposition chamber 11 can be used to deposit and form a spherical dome. Figure 4 The deposition chamber 11 can be used to deposit and form a flat plate. A thermocouple can be installed in the deposition chamber 11.

[0052] Heater 12 can be a graphite heater, which has the characteristics of high heating efficiency and precise and stable temperature control. This allows the temperature required for the polycrystalline zinc sulfide chemical vapor deposition process to be precisely and stably controlled, thereby improving the quality stability and consistency of the prepared polycrystalline zinc sulfide.

[0053] Reference Figure 1 and Figure 2 The chemical vapor deposition furnace 1 also includes an outer deposition chamber 13. The outer deposition chamber 13 is located inside the furnace body 10 and has through holes 131. The outer deposition chamber 13 covers the deposition chamber 11 from all sides and top. A connecting pipe 61 passes through the through holes 101 of the furnace body 10, the through holes 131 of the outer deposition chamber 13, and the through holes 111 of the deposition chamber 11. Therefore, with the deposition chamber 11 constructed from isostatically pressed graphite plates, the outer deposition chamber 13 reduces the amount of dust in the gas leaking from the deposition chamber 11 during deposition that adheres to the inner wall of the furnace body 10 (specifically, the insulation layer 104), thereby reducing the need for cleaning the inner wall of the furnace body 10, lowering costs, and improving production efficiency.

[0054] Similarly, the outer cavity 13 of the deposition chamber can be constructed using isostatically pressed graphite, improving the flexibility of the outer cavity 13 in adapting to the internal space of the furnace body 10 and assembling it according to the outer contour of the deposition chamber 11. A pressure gauge can be installed in the outer cavity 13 of the deposition chamber.

[0055] Based on the configuration of the outer cavity 13 of the deposition chamber, in one example, such as Figure 1 and Figure 2 As shown, heater 12 is located outside the outer cavity 13 of the deposition chamber. Heater 12 covers the outer cavity 13 vertically and is close to the furnace body 10 in the upward direction, partially covering the connecting pipe 61. The closer heater 12 is to the furnace body 10 in the upward direction without hindering its installation and operation, the better. Because heater 12 is located outside the outer cavity 13 and partially covers the connecting pipe 61, the exhaust gas discharged from the deposition chamber 11 via the connecting pipe 61 is still heated by heater 12 (especially when heater 12 is a graphite heater). During the flow of the exhaust gas from the deposition chamber 11 to the furnace body 10, the heating by heater 12 prevents it from cooling down and forming dust. This eliminates the risk of dust falling back into the deposition chamber 11 by gravity and affecting the deposited product, thereby improving the quality of the deposited product in the deposition chamber 11. Furthermore, as... Figure 1 and Figure 2 As shown, heater 12 is located near the bottom of furnace body 10 in a downward direction. In one example, heater 12 is fixed to furnace body 10.

[0056] Reference Figure 1 and Figure 2 In one example, the chemical vapor deposition furnace 1 also includes a support member 14 and a movable cover 15. The support member 14 is located inside the furnace body 10 and supports the deposition chamber 11 and the outer cavity 13 from below. The movable cover 15 is located below the furnace body 10 and is movable to open and close the bottom of the furnace body 10. The movable cover 15 supports the support member 14 from below, supporting the support member 14, deposition chamber 11, and outer cavity 13. The movable cover 15 moves upward to allow the support member 14, deposition chamber 11, and outer cavity 13 to enter the furnace body 10 and contact the bottom of the furnace body 10 to close the furnace body 10. The movable cover 15 moves downward to pull the support member 14, deposition chamber 11, and outer cavity 13 out of the furnace body 10, opening the furnace body 10. This achieves the opening and closing of the furnace body 10. Furthermore, since both opening and closing are performed in the up-down direction, which coincides with the weight direction of the support 14, movable cover 15, deposition chamber 11, and outer cavity 13 of the deposition chamber, the structural stability of the support 14, movable cover 15, deposition chamber 11, and outer cavity 13 of the deposition chamber can be improved during opening and closing. In one example, the support 14 is made of isostatic graphite, and the movable cover 15 is made of stainless steel.

[0057] Reference Figure 1 and Figure 2In one example, the chemical vapor deposition furnace 1 further includes a retainer 16 located between the bottom of the outer cavity 13 of the deposition chamber and the furnace body 10, arranged around the outer cavity 13, and positioned on a support 14 to limit the outer cavity 13 from its periphery. Note that the retainer 16 is spaced apart from the heater 12, and the retainer 16 is movable vertically with the support 14. Thus, the retainer 16 cooperates with the furnace body 10 to guide the outer cavity 13 vertically and to limit its position radially and circumferentially. In one example, the retainer 16 is isostatically pressed graphite.

[0058] like Figure 1 and Figure 2 As shown, in one example, the chemical vapor deposition furnace 1 also includes multiple support rods 17 and a moving mechanism 18. The multiple support rods 17 are fixedly connected to the movable cover 15 from below. The moving mechanism 18 is connected to the multiple support rods 17 and can drive the multiple support rods 17 to move up, down, and horizontally, thereby driving the movable cover 15, together with the support member 14, the deposition chamber 11, and the outer cavity 13 of the deposition chamber to move (i.e., move up and down relative to the furnace body 10, move downwards from the furnace body 10, and then move horizontally, etc.). In one example, the support rods 17 are made of stainless steel. The moving mechanism 18 can employ any known multi-dimensional translation mechanism (or combination thereof) depending on its function, such as a combination of a lifting cylinder and a horizontal movement cylinder.

[0059] like Figure 1 and Figure 2 As shown, in one example, the chemical vapor deposition furnace 1 also includes a support 19 located outside the furnace body 10, which is used to securely support the furnace body 10. The support 19 improves the stability of the furnace body 10. In one example, the support 19 is made of stainless steel.

[0060] Both the first pipe 5A and the second pipe 5B include, from the inside out, an inlet pipe 51, a heating layer 52, an insulation jacket 53, and an outer jacket 54. The heating layer 52 can be a resistance heater or a graphite heater. The heating layer 52 and the insulation jacket 53 ensure that the temperatures of the argon, hydrogen, and sulfur vapor transported through the first pipe 5A are stable along the entire first pipe 5A, and the temperatures of the argon and zinc vapor transported through the second pipe 5B are stable along the entire second pipe 5B. This, in turn, stabilizes the chemical vapor deposition process of the zinc vapor and sulfur vapor supplied to the deposition chamber 11, and ensures the quality of the formed polycrystalline zinc sulfide. Specifically, for example, the inlet pipe 51 is made of graphite; the insulation jacket 53 is made of graphite felt; and the outer jacket 54 is made of stainless steel.

[0061] In one example, the first pipe 5A and the second pipe 5B movably pass through the furnace body 10, the outer cavity 13 of the deposition chamber, and the deposition chamber 11. Note that corresponding sealing rings may or may not be fixed at the locations where they pass through the furnace body 10, the outer cavity 13 of the deposition chamber, and the deposition chamber 11. The movable passage of the first pipe 5A and the second pipe 5B through the furnace body 10, the outer cavity 13 of the deposition chamber, and the deposition chamber 11 improves the flexibility of assembling the furnace body 10, the outer cavity 13 of the deposition chamber, and the deposition chamber 11 with the sulfur melting device 2 and the zinc melting device 3, enabling the opening and closing of the aforementioned furnace body 10, and the simultaneous raising and lowering of the support member 14, the movable cover 15, the deposition chamber 11, and the outer cavity 13 of the deposition chamber. In one example, as... Figure 1 and Figure 2 As shown, the first pipe 5A and the second pipe 5B also movably pass through the heater 12.

[0062] like Figure 1 and Figure 2 As shown, the sulfur melting device 2 is equipped with a sulfur level drop detection mechanism 21, which is used to determine the amount of sulfur evaporation by detecting the drop in the molten sulfur level within the sulfur melting device 2; the zinc melting device 3 is equipped with a zinc level drop detection mechanism 31, which is used to determine the amount of zinc evaporation by detecting the drop in the molten zinc level within the zinc melting device 3. Specifically, for example, the sulfur level drop detection mechanism 21 and the zinc level drop detection mechanism 31 are weighing machines.

[0063] In addition, such as Figure 1 and Figure 2 As shown, the sulfur melting device 2 is equipped with a first heating mechanism 22, which provides heating to the sulfur contained in the sulfur melting device 2 to form sulfur vapor; the zinc melting device 3 is equipped with a second heating mechanism 32, which provides heating to the zinc contained in the zinc melting device 3 to form zinc vapor. Similarly, in one example, both the first heating mechanism 22 and the second heating mechanism 32 are graphite heaters.

[0064] Reference Figure 1 In one example, the extraction device 6 further includes a dust collection pump 62, a vacuum pump 63, and an exhaust gas treatment mechanism 64. The dust collection pump 62 is connected to the connecting pipe 61 and is used to collect dust from the exhaust gas discharged from the outer cavity 13 of the deposition chamber. The vacuum pump 63 is connected to the connecting pipe 61 and is used to evacuate the deposition chamber 11 and maintain the vacuum level within the deposition chamber 11. The exhaust gas treatment mechanism 64 is connected to the vacuum pump 63 and is used to treat the exhaust gas extracted by the vacuum pump 63.

[0065] Reference Figure 1 , Figure 2 and Figure 6In one example, the polycrystalline zinc sulfide chemical vapor deposition system 1000 further includes a support plate 7 and a nozzle 8. The support plate 7 is disposed at the bottom of the deposition chamber 11 and supported on a support member 14. The support plate 7 has a spaced-apart first gas flow channel 71 and second gas flow channel 72. The first gas flow channel 71 connects to a first conduit 5A. The second gas flow channel 72 connects to a second conduit 5B. The nozzle 8 is mounted on the support plate 7 and connects to the first gas flow channel 71 and the second gas flow channel 72, so that argon, hydrogen, and sulfur vapor supplied via the first conduit 5A and the first gas flow channel 71, and argon and zinc vapor supplied via the second conduit 5B and the second gas flow channel 72, are mixed at the nozzle 8 and supplied into the deposition chamber 11. If the argon, hydrogen, and sulfur vapor supplied via the first conduit 5A and the first gas flow channel 71, and the argon and zinc vapor supplied via the second conduit 5B and the second gas flow channel 72, are directly supplied into the deposition chamber 11, the argon, hydrogen, and sulfur vapor mix with the argon and zinc vapor in the deposition chamber 11 for chemical vapor deposition. In this disclosure, the mixture is pre-mixed at the nozzle 8 before entering the deposition chamber 11, which improves the uniformity of the mixing of argon, hydrogen and sulfur vapor with argon and zinc vapor. The mixture is then supplied to the deposition chamber 11 through the nozzle 8. The improvement in the uniformity of the mixing improves the quality of the deposition in the deposition chamber 11.

[0066] The support plate 7 and nozzle 8 can be made of isostatic graphite. For example... Figure 6 As shown, there are multiple nozzles 8, and these nozzles 8 are spaced apart in a single row. The number and number of rows of nozzles 8 can be determined based on the bottom area and two-dimensional dimensions of the bottom area of ​​the sedimentation chamber 11. In one example, the distance between the multiple nozzles 8 is 50-100 mm.

[0067] like Figure 6 As shown, the nozzle 8 is connected to the first airflow channel 71 and the second airflow channel 72 by a corresponding flow channel 73 that is thinner than the first airflow channel 71 and the second airflow channel 72. In this way, the first airflow channel 71 and the corresponding flow channel 73 will undergo a pressurization and acceleration process. Thus, the argon, hydrogen and sulfur vapor supplied by the first airflow channel 71 will be pressurized and accelerated through the corresponding flow channel 73, and the argon and zinc vapor supplied by the second airflow channel 72 will be pressurized and accelerated through the corresponding flow channel 73. As a result, the two pressurized and accelerated fluids at the nozzle 8 will collide and flow upward toward the deposition chamber 11, which improves the uniformity of mixing at the nozzle 8 and improves the quality stability of polycrystalline zinc sulfide deposited by chemical vapor deposition in the deposition chamber 11.

[0068] Reference Figure 1The polycrystalline zinc sulfide chemical vapor deposition system 1000 also includes a control device 9. The control device 9 is communicatively connected to and controls the heater 12, sulfur melting device 2, zinc melting device 3, gas supply device 4, dust collection pump 62, vacuum pump 63, exhaust gas treatment mechanism 64, and even the heating layer 52, moving mechanism 18, sulfur level drop detection mechanism 21, zinc level drop detection mechanism 31, first heating mechanism 22, second heating mechanism 32, thermocouples, and pressure gauges of the chemical vapor deposition furnace 1, thereby improving the automation level of the polycrystalline zinc sulfide chemical vapor deposition process. The control device 9 is, for example, but not limited to, a PLC.

[0069] [Polycrystalline Zinc Sulfide Chemical Vapor Deposition Method]

[0070] The polycrystalline zinc sulfide chemical vapor deposition method disclosed herein employs the aforementioned polycrystalline zinc sulfide chemical vapor deposition system 1000. Further details regarding the features, effects, and operation of the polycrystalline zinc sulfide chemical vapor deposition system 1000 are omitted here.

[0071] The polycrystalline zinc sulfide chemical vapor deposition method includes the following steps:

[0072] High-purity sulfur is placed into sulfur melting device 2; in sulfur melting device 2, the temperature is controlled at 150-250℃ and the vacuum degree is controlled at 4000-8000Pa; high-purity zinc ingots are placed into zinc melting device 3; in zinc melting device 3, the temperature is controlled at 550-650℃ and the vacuum degree is controlled at 3000-6000Pa; the ratio of hydrogen to sulfur evaporation supplied to sulfur melting device 2 by gas supply device 4 is controlled at 1.5-2, and the volume ratio of argon to sulfur vapor supplied to sulfur melting device 2 by gas supply device 4 is controlled at 15-30; gas supply device 4... The volume ratio of argon gas supplied to the zinc melting device 3 to the evaporation of zinc vapor is controlled at 10-20. Sulfur vapor, hydrogen and argon are supplied to the deposition chamber 11 through the first pipe 5A, and zinc vapor and argon are supplied to the deposition chamber 11 through the second pipe 5B. The zinc vapor and sulfur vapor supplied to the deposition chamber 11 are chemically vapor-deposited to form polycrystalline zinc sulfide. The temperature of the deposition chamber 11 is controlled at 620℃-700℃ and the pressure is controlled at 3000-6000Pa. During the reaction in the deposition chamber 11, the volume ratio of zinc vapor to sulfur vapor is controlled at 0.7-0.9.

[0073] According to the polycrystalline zinc sulfide chemical vapor deposition method disclosed herein, polycrystalline zinc sulfide deposited in the deposition chamber 11 can achieve a transmittance >70% in the 8-10 μm range and a hardness HK of 220-230 Kg / mm. 2 .

[0074] [test]

[0075] Example 1

[0076] use Figure 1 The polycrystalline zinc sulfide chemical vapor deposition system 1000 and the aforementioned polycrystalline zinc sulfide chemical vapor deposition method are shown.

[0077] Specifically, the polycrystalline zinc sulfide chemical vapor deposition system includes a chemical vapor deposition furnace 1, a sulfur melting device 2, a zinc melting device 3, a gas supply device 4, a first pipe 5A, a second pipe 5B, a gas extraction device 6, a support plate 7, a nozzle 8, and a control device 9.

[0078] The chemical vapor deposition furnace 1 includes a furnace body 10, a deposition chamber 11, a heater 12, an outer cavity of the deposition chamber 13, a support member 14 and a movable cover 15, a clamping member 16, multiple support rods 17, a moving mechanism 18 and a bracket 19.

[0079] The furnace body 10 forms a three-dimensional closed structure and has a through hole 101 at the top. The furnace body 10 includes an outer wall 102, a cooling jacket 103, and an insulation layer 104. The cooling jacket 103 is located inside the outer wall 102 and is circulated with water as a cooling medium. The insulation layer 104 is located inside the cooling jacket 103. The through hole 101 penetrates the outer wall 102, the cooling jacket 103, and the insulation layer 104. The outer wall 102 is made of stainless steel; the cooling jacket 103 is made of carbon steel or stainless steel. The insulation layer 104 is made of graphite felt.

[0080] The deposition chamber 11 is located inside the furnace body 10 and has a perforation 111 at the top. The deposition chamber 11 is constructed of isostatically pressed graphite plates. Thermocouples are installed in the deposition chamber 11.

[0081] Heater 12 is located outside the outer cavity 13 of the deposition chamber. Heater 12 covers the outer cavity 13 vertically and, in the upward direction, approaches the furnace body 10 to partially cover the connecting pipe 61. Heater 12 is located near the bottom of the furnace body 10 in the downward direction. Heater 12 is a graphite heater. Heater 12 is fixed to the furnace body 10.

[0082] The outer chamber 13 of the deposition chamber is located inside the furnace body 10 and has a through hole 131. The outer chamber 13 covers the deposition chamber 11 from all sides and top. The connecting pipe 61 passes through the through hole 101 of the furnace body 10, the through hole 131 of the outer chamber 13, and the through hole 111 of the deposition chamber 11. The outer chamber 13 of the deposition chamber is constructed of isostatically pressed graphite. A pressure gauge is installed in the outer chamber 13 of the deposition chamber.

[0083] The support member 14 is located inside the furnace body 10 and is used to support the deposition chamber 11 and the outer cavity 13 of the deposition chamber from below. The support member 14 is made of isostatic graphite.

[0084] The movable cover 15 is located below the furnace body 10. The movable cover 15 can be raised and lowered to open and close the bottom of the furnace body 10. The movable cover 15 supports the support member 14 from below, supporting the support member 14, the deposition chamber 11, and the outer cavity 13 of the deposition chamber. The movable cover 15 moves upward to allow the support member 14, the deposition chamber 11, and the outer cavity 13 of the deposition chamber to enter the furnace body 10 and contact the bottom of the furnace body 10 to close the furnace body 10. The movable cover 15 moves downward to pull the support member 14, the deposition chamber 11, and the outer cavity 13 of the deposition chamber out of the furnace body 10 to open the furnace body 10. The movable cover 15 is made of stainless steel.

[0085] The retainer 16 is located between the bottom of the outer cavity 13 of the deposition chamber and the furnace body 10, arranged around the outer cavity 13, and positioned on the support 14 to limit the outer cavity 13 from its surroundings. The retainer 16 is spaced apart from the heater 12. The retainer 16 is made of isostatic graphite.

[0086] Four support rods 17 are fixedly connected to the movable cover 15 from below. The support rods 17 are made of stainless steel.

[0087] The moving mechanism 18 is connected to the plurality of support rods 17 and can drive the four support rods 17 to move up, down and horizontally, thereby driving the movable cover 15 together with the support member 14, the sedimentation chamber 11 and the outer cavity 13 of the sedimentation chamber to move (i.e., move up and down relative to the furnace body 10, move downward out of the furnace body 10 and then move horizontally). The moving mechanism 18 is a combination of a lifting cylinder and a horizontal moving cylinder.

[0088] The bracket 19 is located outside the furnace body 10 and is used to fix the furnace body 10. The bracket 19 is made of stainless steel.

[0089] The sulfur melting device 2 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The sulfur melting device 2 is used to hold sulfur and heat it to evaporate it into sulfur vapor. The sulfur melting device 2 is equipped with a sulfur level drop detection mechanism 21 in the form of a weighing machine. This mechanism determines the amount of sulfur evaporation by detecting the drop in the molten sulfur level within the sulfur melting device 2. The sulfur melting device 2 is equipped with a first heating mechanism 22, which provides heating to the sulfur contained in the device to form sulfur vapor. The zinc melting device 3 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The zinc melting device 3 is used to hold zinc-sulfur and heat it to evaporate it into zinc vapor. The zinc melting device 3 is equipped with a zinc level drop detection mechanism 31 in the form of a weighing machine. This mechanism determines the amount of zinc evaporation by detecting the drop in the molten zinc level within the device. The zinc melting device 3 is equipped with a second heating mechanism 32, which provides heating to the zinc contained in the zinc melting device 3 to form zinc vapor. Both the first heating mechanism 22 and the second heating mechanism 32 are graphite heaters.

[0090] The gas supply device 4 is located outside the furnace body 10 of the chemical vapor deposition furnace 1. The gas supply device 4 is used to supply argon gas to the sulfur melting device 2 and to supply argon gas and hydrogen gas to the zinc melting device 3.

[0091] The first conduit 5A connects the sulfur melting device 2 and the deposition chamber 11 to supply argon, hydrogen, and sulfur vapor from the sulfur melting device 2 into the deposition chamber 11. The second conduit 5B connects the zinc melting device 3 and the deposition chamber 11 to supply argon and zinc vapor from the zinc melting device 3 into the deposition chamber 11. The first conduit 5A and the second conduit 5B movably pass through the furnace body 10, the heater 12, the outer cavity 13 of the deposition chamber 11, and the deposition chamber 11. Both the first conduit 5A and the second conduit 5B include, from the inside out, an inlet pipe 51, a heating layer 52, an insulation jacket 53, and an outer sleeve 54. The inlet pipe 51 is made of graphite; the insulation jacket 53 is made of graphite felt; and the outer sleeve 54 is made of stainless steel. The heating layer 52 is a graphite heater. The first conduit 5A and the second conduit 5B movably pass through the furnace body 10, the outer cavity 13 of the deposition chamber 13, and the deposition chamber 11.

[0092] The extraction device 6 includes a connecting pipe 61, a dust collection pump 62, a vacuum pump 63, and a tail gas treatment mechanism 64. The connecting pipe 61 passes through the through hole 101 of the furnace body 10 and the through hole 111 of the sedimentation chamber 11, and the extraction device 6 is connected to the sedimentation chamber 11 via the connecting pipe 61. The dust collection pump 62 is connected to the connecting pipe 61 and is used to collect dust from the tail gas discharged from the outer cavity 13 of the sedimentation chamber; the vacuum pump 63 is connected to the connecting pipe 61 and is used to evacuate the sedimentation chamber 11 and maintain the vacuum level inside the sedimentation chamber 11; the tail gas treatment mechanism 64 is connected to the vacuum pump 63 and is used to treat the tail gas extracted by the vacuum pump 63.

[0093] A support plate 7 is disposed at the bottom of the deposition chamber 11 and supported on a support member 14. The support plate 7 has a first airflow channel 71 and a second airflow channel 72 spaced apart. The first airflow channel 71 connects to a first pipe 5A, and the second airflow channel 72 connects to a second pipe 5B. Nozzles 8 are mounted on the support plate 7, and the nozzles 8 are connected to the first airflow channel 71 and the second airflow channel 72 by opposing flow channels 73 that are narrower than the first airflow channel 71 and the second airflow channel 72. The support plate 7 and the nozzles 8 are made of isostatic graphite. There are seven nozzles 8, which are spaced apart in a single row. The distance between the seven nozzles 8 is 50-100 mm.

[0094] The control device 9 is communicatively connected to and controls the heater 12, sulfur melting device 2, zinc melting device 3, gas supply device 4, dust collection pump 62, vacuum pump 63, exhaust gas treatment mechanism 64, heating layer 52, moving mechanism 18, sulfur level drop detection mechanism 21, zinc level drop detection mechanism 31, first heating mechanism 22, second heating mechanism 32, pressure gauge, and thermocouple of the chemical vapor deposition furnace 1. The control device 9 is a PLC.

[0095] Based on the aforementioned installation of the polycrystalline zinc sulfide chemical vapor deposition system, the polycrystalline zinc sulfide chemical vapor deposition method employs the following steps:

[0096] Place 5N high-purity sulfur into sulfur melting device 2;

[0097] In the sulfur melting device 2, the temperature of the sulfur melting device 2 is controlled at 150°C (heated by the first heating structure 22), and the vacuum degree is controlled at 4000Pa.

[0098] Place the 5N high-purity zinc ingot into the zinc melting device 3;

[0099] In the zinc melting device 3, the temperature of the molten zinc is controlled at 550°C (heated by the second heating structure 32), and the vacuum degree is controlled at 3000Pa.

[0100] The ratio of hydrogen to sulfur evaporation supplied by gas supply device 4 to sulfur melting device 2 is controlled at 1.5, and the volume ratio of argon to sulfur vapor supplied by gas supply device 4 to sulfur melting device 2 is controlled at 15. The amount of sulfur vapor is detected by sulfur liquid level drop detection mechanism 21 in the form of a weighing machine.

[0101] The volume ratio of the amount of argon gas supplied by the gas supply device 4 to the amount of zinc vapor evaporation is controlled at 10-20. The amount of zinc vapor is detected by the zinc liquid level drop detection mechanism 31 in the form of a weighing machine.

[0102] Sulfur vapor, hydrogen, and argon are supplied to the deposition chamber 11 through the first pipe 5A, while zinc vapor and argon are supplied to the deposition chamber 11 through the second pipe 5B. The zinc vapor and sulfur vapor supplied to the deposition chamber 11 are chemically vapor-deposited to form polycrystalline zinc sulfide. The temperature of the deposition chamber 11 is controlled at 620°C (detected by a thermocouple installed in the deposition chamber 11), and the pressure is controlled at 3000 Pa (detected by a pressure gauge installed in the outer cavity 13 of the deposition chamber). During the reaction in the deposition chamber 11, the volume ratio of zinc vapor to sulfur vapor is controlled at 0.7.

[0103] Example 2

[0104] Except for the following differences, everything is the same as in Example 1:

[0105] In the sulfur melting device 2, the temperature is controlled at 200℃ and the vacuum degree is controlled at 6000Pa.

[0106] In the zinc melting device 3, the temperature of the zinc melting is controlled at 600℃ and the vacuum degree is controlled at 5000Pa;

[0107] The ratio of hydrogen to sulfur evaporation supplied by gas supply device 4 to sulfur melting device 2 is controlled at 1.7, and the volume ratio of argon to sulfur vapor supplied by gas supply device 4 to sulfur melting device 2 is controlled at 20.

[0108] The volume ratio of the amount of argon gas supplied by the gas supply device 4 to the amount of zinc vapor evaporation is controlled at 15.

[0109] The temperature of the deposition chamber 11 is controlled at 650℃ and the pressure is controlled at 5000Pa. During the reaction process in the deposition chamber 11, the volume ratio of zinc vapor to sulfur vapor is controlled at 0.8.

[0110] Example 3

[0111] Except for the following differences, everything is the same as in Example 1:

[0112] In the sulfur melting device 2, the temperature is controlled at 250℃ and the vacuum degree is controlled at 8000Pa.

[0113] In the zinc melting device 3, the temperature of the zinc melting is controlled at 650℃ and the vacuum degree is controlled at 6000Pa;

[0114] The ratio of hydrogen to sulfur evaporation supplied by gas supply device 4 to sulfur melting device 2 is controlled at 2, and the volume ratio of argon to sulfur vapor supplied by gas supply device 4 to sulfur melting device 2 is controlled at 30.

[0115] The volume ratio of the amount of argon gas supplied by the gas supply device 4 to the amount of zinc vapor evaporation is controlled at 20.

[0116] The temperature of the deposition chamber 11 is controlled at 700℃ and the pressure is controlled at 6000Pa. During the reaction process in the deposition chamber 11, the volume ratio of zinc vapor to sulfur vapor is controlled at 0.9.

[0117] After the chemical vapor deposition in Examples 1-3 is completed, the first pipe 5A and the second pipe 5B are removed. The moving mechanism 18 is activated, which drives the multiple support rods 17 to move up, down and horizontally. This allows the movable cover 15, along with the deposition chamber 11, the outer cavity of the deposition chamber 13, the support member 14, the clamp 16, the support plate 7, and the nozzle 8, to move downward out of the furnace body 10. The outer cavity of the deposition chamber 13 is then disassembled, the deposition chamber 11 is disassembled, and the deposited polycrystalline zinc sulfide is removed. Transmittance and hardness tests are then performed in the range of 8-10 μm.

[0118] In Example 1, the polycrystalline zinc sulfide exhibited a transmittance of 71% in the 8-10 μm range and a hardness HK of 230 kg / mm. 2 .

[0119] In Example 2, the polycrystalline zinc sulfide exhibited a transmittance of 72% in the 8-10 μm range and a hardness HK of 224 kg / mm. 2 .

[0120] The polycrystalline zinc sulfide in Example 3 had a transmittance of 73% in the 8-10 μm range and a hardness HK of 220 kg / mm. 2 .

[0121] Combining Examples 1-3, the polycrystalline zinc sulfide formed by chemical vapor deposition in deposition chamber 11 exhibits a transmittance >70% in the 8-10 μm range and a hardness HK of 220-230 Kg / mm. 2 .

[0122] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.

Claims

1. A polycrystalline zinc sulfide chemical vapor deposition system, characterized in that, The polycrystalline zinc sulfide chemical vapor deposition system (1000) includes a chemical vapor deposition furnace (1), a sulfur melting device (2), a zinc melting device (3), a gas supply device (4), a first pipeline (5A), a second pipeline (5B), and a gas extraction device (6); The chemical vapor deposition furnace (1) includes a furnace body (10), a deposition chamber (11), and a heater (12); The furnace body (10) forms a three-dimensional closed structure and has a through hole (101) at the top, so that the furnace body (10) can be opened and closed; The deposition chamber (11) is located inside the furnace body (10) and has a perforation (111) at the top; The heater (12) is located inside the furnace body (10) and around the deposition chamber (11). The heater (12) is used to heat the deposition chamber (11) from outside the deposition chamber (11). The sulfur melting device (2) is located outside the furnace body (10) of the chemical vapor deposition furnace (1). The sulfur melting device (2) is used to hold sulfur and heat and evaporate the sulfur to form sulfur vapor. The zinc melting device (3) is located outside the furnace body (10) of the chemical vapor deposition furnace (1). The zinc melting device (3) is used to hold zinc and heat and evaporate the zinc to form zinc vapor. The gas supply device (4) is located outside the furnace body (10) of the chemical vapor deposition furnace (1). The gas supply device (4) is used to supply argon and hydrogen to the sulfur melting device (2) and to supply argon to the zinc melting device (3). The first conduit (5A) connects the sulfur melting device (2) and the deposition chamber (11) to supply argon, hydrogen and sulfur vapor from the sulfur melting device (2) into the deposition chamber (11); The second pipe (5B) connects the zinc melting device (3) and the deposition chamber (11) to supply argon and zinc vapor from the zinc melting device (3) into the deposition chamber (11); The deposition chamber (11) is used to chemically vapor-deposit zinc vapor and sulfur vapor supplied to the deposition chamber (11) to form polycrystalline zinc sulfide; The extraction device (6) includes a connecting pipe (61), which seals the through hole (101) passing through the furnace body (10) and the perforation (111) of the deposition chamber (11). The extraction device (6) is connected to the deposition chamber (11) via the connecting pipe (61) to evacuate the deposition chamber (11) and extract the tail gas formed during the chemical vapor deposition process of zinc vapor and sulfur vapor.

2. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 1, characterized in that, The chemical vapor deposition furnace (1) also includes an outer cavity (13) for the deposition chamber. The outer cavity (13) of the deposition chamber is located inside the furnace body (10) and has a through hole (131); The outer cavity (13) of the sedimentation chamber covers the sedimentation chamber (11) from all sides and the top; The connecting pipe (61) seals the through hole (101) through the furnace body (10), the through hole (131) of the outer cavity of the sedimentation chamber (13), and the through hole (111) of the sedimentation chamber (11).

3. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 2, characterized in that, The sedimentation chamber (11) is constructed by overlapping isostatically pressed graphite plates; The outer cavity of the deposition chamber (13) is made of isostatically pressed graphite.

4. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 2, characterized in that, The heater (12) is located outside the outer cavity (13) of the deposition chamber. The heater (12) covers the outer cavity (13) of the deposition chamber in the vertical direction and is close to the furnace body (10) in the upward direction to cover part of the connecting pipe (61). The heater (12) is close to the bottom of the furnace body (10) in the downward direction.

5. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 2, characterized in that, The chemical vapor deposition furnace (1) also includes a support (14) and a movable cover (15). The support member (14) is located inside the furnace body (10) and is used to support the deposition chamber (11) and the outer cavity (13) of the deposition chamber from below; The movable cover (15) is located below the furnace body (10). The movable cover (15) can be raised and lowered to open and close the bottom of the furnace body (10). The movable cover (15) is used to support the support member (14) from below to support the support member (14), the sedimentation chamber (11) and the outer cavity of the sedimentation chamber (13). The movable cover (15) moves upward to allow the support member (14), the sedimentation chamber (11) and the outer cavity of the sedimentation chamber (13) to enter the furnace body (10) and the movable cover (15) contacts the bottom of the furnace body (10) to close the furnace body (10). The movable cover (15) moves downward to drive the support member (14), the sedimentation chamber (11) and the outer cavity of the sedimentation chamber (13) out of the furnace body (10) to open the furnace body (10).

6. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 4, characterized in that, The first pipe (5A) and the second pipe (5B) pass through the furnace body (10), the outer cavity of the deposition chamber (13), the deposition chamber (11), and the heater (12).

7. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 5, characterized in that, The polycrystalline zinc sulfide chemical vapor deposition system (1000) also includes a support plate (7) and a nozzle (8); The support plate (7) is located at the bottom of the sedimentation chamber (11) and supported on the support member (14). The support plate (7) is provided with a first airflow channel (71) and a second airflow channel (72) spaced apart; The first airflow channel (71) is connected to the first pipe (5A). The second airflow channel (72) connects to the second pipe (5B). The nozzle (8) is mounted on the support plate (7) and is connected to the first airflow channel (71) and the second airflow channel (72) so that the argon, hydrogen and sulfur vapor supplied through the first pipe (5A) and the first airflow channel (71) and the argon and zinc vapor supplied through the second pipe (5B) and the second airflow channel (72) are mixed at the nozzle (8) and supplied into the deposition chamber (11).

8. The polycrystalline zinc sulfide chemical vapor deposition system according to claim 7, characterized in that, The nozzle (8) is connected to the first airflow channel (71) and the second airflow channel (72) by a relative flow channel (73) that is narrower than the first airflow channel (71) and the second airflow channel (72).

9. A method for chemical vapor deposition of polycrystalline zinc sulfide, characterized in that, The polycrystalline zinc sulfide chemical vapor deposition method employs the polycrystalline zinc sulfide chemical vapor deposition system (1000) as described in any one of claims 1-8; The polycrystalline zinc sulfide chemical vapor deposition method includes the following steps: High-purity sulfur is placed into the sulfur melting device (2); In the sulfur melting device (2), the temperature of the sulfur melting device (2) is controlled at 150-250℃ and the vacuum degree is controlled at 4000-8000Pa; Place the high-purity zinc ingots into the zinc melting device (3); In the zinc melting device (3), the temperature of the zinc melting is controlled at 550-650℃, and the vacuum degree is controlled at 3000-6000Pa; The ratio of hydrogen to sulfur evaporation in the gas supply device (4) to the sulfur melting device (2) is controlled at 1.5-2, and the volume ratio of argon to sulfur vapor in the gas supply device (4) to the sulfur melting device (2) is controlled at 15-30. The volume ratio of the amount of argon gas supplied by the gas supply device (4) to the amount of zinc vapor evaporation is controlled at 10-20. Sulfur vapor, hydrogen and argon are supplied to the deposition chamber (11) through the first pipe (5A), and zinc vapor and argon are supplied to the deposition chamber (11) through the second pipe (5B). The zinc vapor and sulfur vapor supplied to the deposition chamber (11) are chemically vapor-deposited to form polycrystalline zinc sulfide. The temperature of the deposition chamber (11) is controlled at 620℃-700℃ and the pressure is controlled at 3000-6000Pa. During the reaction in the deposition chamber (11), the volume ratio of zinc vapor to sulfur vapor is controlled at 0.7-0.

9.

10. The polycrystalline zinc sulfide chemical vapor deposition method according to claim 9, characterized in that, Polycrystalline zinc sulfide formed by chemical vapor deposition in deposition chamber (11) has a transmittance of >70% in the 8-10 μm range and a hardness HK of 220-230 Kg / mm. 2 .

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