Microwave plasma chemical vapor deposition equipment

Abstract

The invention relates to the field of microwave plasma processing equipment, in particular to microwave plasma chemical vapor deposition equipment. The microwave plasma chemical vapor deposition equipment comprises a furnace tube in which a plasma cavity is formed, and the formed plasma cavity comprises an upper short circuit plate, a side wall and a lower short circuit plate; a substrate cold water table group is arranged above the lower short circuit plate, and a wafer is placed at the upper end of the substrate cold water table group; an air disc is arranged on the outer side of the upper end of the wafer; according to the microwave plasma chemical vapor deposition equipment, the gas disc is arranged above the wafer placed in the plasma cavity, so that the consistency of the concentration and the uniform distribution of the raw material gas at the upper end of the wafer can be fully ensured, and the uniformity of the concentration and the thickness of a substance deposited in the later period is further ensured; and particularly, the concentration of the deposited substances at the edge of the wafer can be ensured to be consistent, so that the quality of the produced deposited substances is relatively high.

Description

Technical Field

[0001] The invention relates to the field of microwave plasma processing equipment, in particular to microwave plasma chemical vapor deposition equipment. Background Art

[0002] Microwave plasma CVD device is a process device that uses microwave energy to achieve chemical vapor deposition. It has the advantages of large output, high quality and low cost. Its principle is that microwaves resonate in the plasma cavity, forming a strong electromagnetic field center area, ionizing the gas to form plasma, and then forming solid material deposition on the surface of the deposition substrate.

[0003] Microwave plasma CVD (MPCVD) is one of the methods for growing high-quality single crystal diamond (SCD) and polycrystalline diamond (PCD). In order to reduce impurities and improve the crystal quality of synthetic diamond, it is important to extend the continuous deposition time as much as possible while maintaining the growth conditions, keep the plasma away from the microwave window usually made of quartz, reduce the corrosion of quartz to avoid releasing impurity silicon, and prevent damage to the quartz window;

[0004] See also Figure 1 , a microwave plasma CVD device is provided in the related art, and the microwave plasma CVD device comprises: a furnace tube 2, wherein a plasma cavity 7 is formed inside the furnace tube 2, and the formed plasma cavity 7 comprises an upper short-circuit plate 14, a side wall and a lower short-circuit plate 11;

[0005] The upper short-circuit plate 14 is movably mounted on the upper end of the side wall, and an opening is provided in the middle of the upper short-circuit plate 14; the lower short-circuit plate 11 is movably mounted on the lower end of the side wall; a waveguide 3 is mounted on the upper short-circuit plate 14, and the waveguide 3 is located above the opening provided in the middle of the upper short-circuit plate 14; the bottom end of the waveguide 3 is connected to the upper short-circuit plate 14; an excitation probe 4 is provided inside the opening, and the excitation probe 4 includes a longitudinal probe portion 41 and a transverse probe portion 42; a microwave window 5 is also provided between the lower end of the upper short-circuit plate 14 and the excitation probe 4;

[0006] A substrate cooling water table group 13 is provided above the lower short-circuit plate 11, and the substrate cooling water table group 13 includes an outer cooling water jacket 131 and an inner cooling water table 133 movably provided on the outer cooling water jacket 131; a wafer 8 is placed on the upper end of the substrate cooling water table group 13; the wafer 8 is located between the excitation probe 4 and the substrate cooling water table group 13; in addition, a flange end 9 is provided on the outer side of the movable lower short-circuit plate 11, and the lower end of the flange end 9 is fixed on the furnace tube 2 through a flange pipe 10; a gas injection port 6 is opened at the side wall of the plasma chamber 7, and the gas injection port 6 is used to introduce raw material gas into the plasma chamber 7;

[0007] In addition, the distance between the upper surface of the outer water cooling jacket 131 and the lower short-circuit plate 11 is L2, the distance between the table surface of the inner water cooling platform 133 and the upper surface of the outer water cooling jacket 131 is L3; the distance between the upper surface of the outer water cooling jacket and the end surface of the flange end of the flange-shaped side wall is L5;

[0008] When the microwave plasma CVD device is used, the generated microwaves pass through the microwave window 5 and enter the plasma cavity 7 through the cooperation of the waveguide 3 and the excitation probe 4. After the microwaves enter the plasma cavity 7, plasma is formed at a place in the plasma cavity 7 where the electromagnetic energy is large enough, so as to form a deposited material on the upper surface of the wafer 8.

[0009] The microwave plasma CVD device is provided with movable components so that L2 and L3 are in an adjustable state. Such a configuration facilitates the adjustment of the impedance in the plasma cavity to maximize the absorption of microwaves and keep the generated plasma away from the quartz window. At the same time, the shape of the plasma near the substrate cooling water table group is changed to maximize the contact between the plasma and the deposition substrate, change the energy density of the plasma, or maintain the relative position of the deposition substrate and the plasma during growth.

[0010] In addition, when L5 is in an adjustable state through further settings, the plasma can be better kept away from the quartz window, which can effectively prevent the window from becoming black and overheating after the plasma chamber has been operating for a long time, thereby reducing the efficiency of microwave transmission to the plasma body and preventing the plasma from etching the window during operation, resulting in the release of impurity silicon and affecting the quality of diamond growth;

[0011] However, the microwave plasma CVD device also has some defects. For example, the raw material gas used for the chemical vapor deposition reaction inside the plasma chamber 7 is injected through the gas injection port 6 opened on one side of the side wall. When the chemical vapor deposition reaction is carried out, since the raw material gas is slowly supplied to one side in a unidirectional manner, the concentration of the raw material gas at the position above the wafer is different. The raw material gas concentration is higher near the gas injection port, while the raw material gas concentration is lower at the position far from the gas injection port. In addition, the wafer used for depositing the material is disc-shaped, so the raw material gas concentration at both ends above the wafer far from the flow direction of the raw material gas will be lower, which ultimately causes the material deposited on the crystal disc by the chemical vapor phase to be unevenly distributed and unevenly thick, resulting in poor product quality. At the same time, after the gas supply is stopped, the gas pressure inside the plasma chamber 7 is greater than the external pressure, which will cause the high-temperature raw material gas to return along the conveying pipeline. If the gas injection port 6 is not closed in time, part of the raw material gas will be lost, and the remaining chemical deposition reaction will be difficult to continue due to insufficient loss of raw material gas.

[0012] In view of the problems in the above background technology, the present invention aims to provide a microwave plasma chemical vapor deposition device. Summary of the invention

[0013] The object of the present invention is to provide a microwave plasma chemical vapor deposition device to solve the problems of uneven thickness and poor quality of deposited materials mentioned in the above background technology.

[0014] To achieve the above object, the present invention provides the following technical solutions:

[0015] A microwave plasma chemical vapor deposition device, the microwave plasma chemical vapor deposition device comprising:

[0016] A furnace tube, wherein the furnace tube is used to realize chemical vapor deposition on the wafer placed therein by microwaves; wherein a plasma cavity is formed inside the furnace tube, and the formed plasma cavity includes an upper short-circuit plate, a side wall and a lower short-circuit plate;

[0017] The upper short-circuit plate is movably mounted on the upper end of the side wall, and an opening is provided in the middle of the upper short-circuit plate; the lower short-circuit plate is movably mounted on the lower end of the side wall;

[0018] A waveguide is installed on the upper short-circuit plate, and the bottom end of the waveguide is connected to the upper short-circuit plate; an excitation probe is arranged inside the opening, and a microwave window is also arranged between the lower end of the upper short-circuit plate and the excitation probe; a substrate cooling water table group is arranged above the lower short-circuit plate, and a wafer is placed on the upper end of the substrate cooling water table group;

[0019] At the same time, a gas disk is provided on the outer side of the upper end of the wafer, which is used to evenly supply raw material gas to the upper surface of the wafer in multiple angles during chemical deposition operations on the wafer. It can also prevent gas leakage inside the plasma chamber when the gas supply is stopped, reduce the gas pressure, and affect the generation of deposited materials on the wafer surface in the later stage.

[0020] As a further solution of the present invention: the excitation probe is a water-cooled excitation probe, which includes a longitudinal probe portion and a transverse probe portion. The longitudinal probe portion is arranged at the center of the waveguide, and the end of the longitudinal probe portion extends into the plasma chamber; the transverse probe portion is annular and is located at the end of the longitudinal probe portion.

[0021] As a further solution of the present invention: the substrate cooling water table group includes an outer cooling water jacket and an inner cooling water table movably arranged on the outer cooling water jacket; the inner cooling water table is at least partially located inside the plasma chamber and is arranged opposite to the lateral probe portion; at the same time, the lower part of the inner cooling water table extends out of the plasma chamber through the opening behind the lower short-circuit plate; in addition, a cooling pipeline is provided inside the outer cooling water jacket, and a cooling medium flows inside the provided cooling pipeline.

[0022] As a further solution of the present invention: upper threaded rods are symmetrically installed on an upper short-circuit plate movably installed at the upper end of the side wall; lower threaded rods are symmetrically installed on a lower short-circuit plate movably installed at the lower end of the side wall; and a flange end is provided on the outer side of the movably displaceable lower short-circuit plate, and the lower end of the flange end is fixed to the furnace tube through a flange pipe.

[0023] As a further solution of the present invention: the two sides of the bottom end of the gas disk are symmetrically connected to the air intake riser and the temporary air riser respectively, and the lower ends of the air intake riser and the temporary air riser are both arranged to pass through the flange ends symmetrically distributed inside the plasma chamber; at the same time, the lower end of the air intake riser is provided with an end, and one end of the end is connected to the corrugated pipe.

[0024] As a further solution of the present invention: a tray is provided at the lower end of the inner wall of the gas disk, and diffuser pipes are installed on the tray in a ring-shaped distribution, and the installed diffuser pipes are connected to the inside of the gas disk.

[0025] As a further solution of the present invention: a diffusion chamber is formed inside the diffuser tube, an air inlet is provided at one end of the diffusion chamber, an exhaust port is provided at the other end of the diffusion chamber, and the diameter of the exhaust port is smaller than the diameter of the air inlet; at the same time, a valve plate is movably installed in the diffusion chamber at the position where the air inlet is provided.

[0026] A microwave plasma chemical vapor deposition device, the microwave plasma chemical vapor deposition device comprising:

[0027] A furnace tube, wherein the furnace tube is used to realize chemical vapor deposition on the wafer placed therein by microwaves; wherein a plasma cavity is formed inside the furnace tube, and the formed plasma cavity includes an upper short-circuit plate, a side wall and a lower short-circuit plate;

[0028] The upper short-circuit plate is movably mounted on the upper end of the side wall, and an opening is provided in the middle of the upper short-circuit plate; the lower short-circuit plate is movably mounted on the lower end of the side wall;

[0029] A waveguide is installed on the upper short-circuit plate, and the bottom end of the waveguide is connected to the upper short-circuit plate; an excitation probe is arranged inside the opening, and a microwave window is also arranged between the lower end of the upper short-circuit plate and the excitation probe; a substrate cooling water table group is arranged above the lower short-circuit plate, and a wafer is placed on the upper end of the substrate cooling water table group;

[0030] At the same time, the inner wall of the plasma chamber 7 is symmetrically and evenly distributed with a diffuser tube 20 which is used to provide raw material gas to the upper surface of the wafer evenly and simultaneously in multiple angles during chemical deposition operations on the wafer. It can also prevent gas leakage inside the plasma chamber when the gas supply is stopped, reduce the gas pressure, and affect the generation of deposited materials on the wafer surface in the later stage.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] Compared with the current microwave plasma CVD devices, the microwave plasma chemical vapor deposition equipment has the following advantages:

[0033] First, a gas disk is arranged above the wafer placed inside the plasma chamber to replace the original gas injection port on the side wall at one end of the plasma chamber; wherein a tray is provided at the lower end of the inner wall of the gas disk, and a diffuser is installed on the tray in an annular manner, and the installed diffuser is connected to the inside of the gas disk; when the raw material gas is transported through the gas disk, the raw material gas can be uniformly transported and covered in multiple angles to the upper surface of the wafer through the annular diffuser, so that the raw material gas concentration at the upper end of the wafer is uniform and evenly distributed, thereby ensuring that the concentration and thickness of the deposited material in the later stage are uniform, and in particular, it can also ensure that the concentration of the deposited material at the edge of the wafer is also consistent, so that the quality of the deposited material produced is higher;

[0034] 2. After the raw material gas enters the pressure diffusion chamber, it is temporarily stored inside the pressure diffusion chamber and then discharged through the exhaust port. Since the diameter of the exhaust port is smaller than that of the air inlet, the gas discharged from the exhaust port can be discharged after being pressurized and accelerated, thereby improving the efficiency of the chemical vapor deposition reaction. After the raw material gas stops supplying gas in the later stage, the valve plate set can restore the valve plate to its initial state under the action of its own gravity and the pressure difference between the inside of the plasma chamber and the outside world (the air pressure inside the plasma chamber is greater than the outside air pressure), which is used to cause blockage at the air inlet position and constitute a one-way valve, thereby preventing the reaction gas inside the plasma chamber from returning to the inside of the gas disk and being discharged in the opposite direction along the input pipeline, thereby reducing the loss of raw material gas and preventing the remaining chemical deposition reaction from being difficult to continue due to insufficient loss of raw material gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0036] Figure 1 It is a schematic diagram of the structure of a microwave plasma CVD device in the prior art.

[0037] Figure 2 This is a schematic diagram of the structure of a microwave plasma chemical vapor deposition device in Example 1 of the present invention.

[0038] Figure 3 This is a schematic diagram of the structure of a gas disk of a microwave plasma chemical vapor deposition device in Example 1 of the present invention.

[0039] Figure 4 This is a top view of a gas disk of a microwave plasma chemical vapor deposition device in Example 1 of the present invention.

[0040] Figure 5 This is a schematic diagram of the structure of a diffuser tube of a microwave plasma chemical vapor deposition device in Example 1 of the present invention.

[0041] Figure 6 This is a schematic structural diagram of a microwave plasma chemical vapor deposition device in Example 2 of the present invention.

[0042] In the figure: 1-upper threaded rod, 2-furnace tube, 3-waveguide, 4-excitation probe, 41-longitudinal probe part, 42-lateral probe part, 5-microwave window, 6-gas injection port, 7-plasma cavity, 8-wafer, 9-flange end, 10-flange pipe, 11-lower short-circuit plate, 12-lower threaded rod, 13-substrate cooling water table group, 131-outer cooling water jacket, 132-cooling pipeline, 133-inner water cooling table, 14-upper short-circuit plate, 15-gas plate, 16-inlet riser, 17-terminal, 18-bellows, 19-temporary gas riser, 20-diffuser, 21-tray, 22-inlet, 23-valve plate, 24-diffuser cavity, 25-exhaust port. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention;

[0044] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there can be an intermediate element at the same time;

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0046] Example 1

[0047] See also Figure 2 , a microwave plasma chemical vapor deposition device provided in embodiment 1 of the present invention, the microwave plasma chemical vapor deposition device comprises:

[0048] A furnace tube 2, wherein the furnace tube 2 is used to perform chemical vapor deposition on a wafer 8 placed therein by microwaves; wherein a plasma chamber 7 is formed inside the furnace tube 2, and the formed plasma chamber 7 includes an upper short-circuit plate 14, a side wall, and a lower short-circuit plate 11;

[0049] The upper short-circuit plate 14 is movably mounted on the upper end of the side wall, and an opening is provided in the middle of the upper short-circuit plate 14, and the opening is used to introduce microwaves; the lower short-circuit plate 11 is movably mounted on the lower end of the side wall;

[0050] A waveguide 3 is mounted on the upper short-circuit plate 14, and the waveguide 3 is located above the opening in the middle of the upper short-circuit plate 14; the bottom end of the waveguide 3 is connected to the upper short-circuit plate 14, and the waveguide 3 is used to introduce the microwave into the opening; for the waveguide 3, suitable metals such as stainless steel or aluminum are used; but in order to reduce the transmission loss of microwaves, the inner surface is preferably plated with a metal with a low resistivity, such as gold, silver or copper; the frequency band wavelength of the microwaves is not limited here, as long as they have a wavelength that can generate plasma; an excitation probe 4 is provided inside the opening, and the excitation probe 4 is used to introduce the microwave into the plasma cavity 7; a microwave window 5 is also provided between the lower end of the upper short-circuit plate 14 and the excitation probe 4, and the microwave window 5 is also used to introduce the microwave into the plasma cavity 7 and keep the inside of the plasma cavity 7 at a preset vacuum, and the microwave window 5 is made of quartz or a material that can make microwaves transparent;

[0051] A substrate cooling water table group 13 is provided above the lower short-circuit plate 11, and a wafer 8 is placed on the upper end of the substrate cooling water table group 13; the wafer 8 is located between the excitation probe 4 and the substrate cooling water table group 13; the placed wafer 8 is used for chemical vapor deposition to produce solid substances on its surface; at the same time, a gas disk 15 is provided on the outer side of the upper end of the wafer 8, and the gas disk 15 is used to uniformly and multi-angle directions to simultaneously provide raw material gas to the upper end surface of the wafer 8 when the wafer 8 is subjected to chemical deposition operation, and can also avoid gas leakage inside the plasma chamber 7 when the gas supply is stopped, reduce the gas pressure, and affect the generation of deposited substances on the surface of the wafer 8 in the later stage; the raw material gas includes a first raw material gas and a second raw material gas, the first raw material gas is at least one of hydrogen, helium and argon; the second raw material gas is hydrocarbon gas or hydrocarbon gas and oxygen-containing gas (such as O 2 ,CO,CO 2 ), nitrogen-containing gases (such as N 2 NH 3 ,NO,NO 2 ), Boron-containing gas (BF 3 , BCl 3 , B 2 H 6 , C 6 H 15 B.C 3 H 9B), phosphorus-containing gases (such as P 4 PF 3 PF 5 , PH 3 ) a mixture of at least one of ;

[0052] In the embodiment of the present invention, when the microwave plasma chemical vapor deposition device is used, the generated microwaves pass through the microwave window 5 and enter the plasma cavity 7 through the cooperation of the provided waveguide 3 and the excitation probe 4;

[0053] After the microwave enters the plasma cavity 7, plasma is formed in the place where the electromagnetic energy is large enough in the plasma cavity 7; by adjusting the distance between the substrate cooling water table group 13 and the lower short-circuit plate 11, the impedance matching with the plasma cavity 7 can be improved to maximize the absorption of microwaves and keep the generated plasma away from the microwave window 5. At the same time, by changing the shape of the plasma near the substrate cooling water table group 13, the contact between the plasma and the wafer 8 can be maximized, the energy density of the plasma can be changed, or the relative position of the deposition substrate and the plasma during growth can be maintained;

[0054] In addition, when the wafer 8 is subjected to chemical deposition, the gas disk 15 can evenly provide the raw material gas to the upper surface of the wafer 8 in multiple angles and directions, and can also prevent the gas from leaking inside the plasma chamber 7 when the gas supply is stopped, thereby reducing the gas pressure and affecting the generation of deposited materials on the surface of the wafer 8 in the later stage;

[0055] See also Figure 2 In one embodiment of the present invention, the excitation probe 4 is a water-cooled excitation probe, and the excitation probe 4 includes a longitudinal probe portion 41 and a transverse probe portion 42. The longitudinal probe portion 41 is arranged at the center of the waveguide 3, and the end of the longitudinal probe portion 41 extends into the plasma chamber 7; the transverse probe portion 42 is annular and is located at the end of the longitudinal probe portion 41;

[0056] The longitudinal probe part 41 is used to vertically introduce microwaves into the plasma cavity 7, while the annular transverse probe part 42 can evenly and effectively cover the upper surface of the wafer 8 installed in the plasma cavity 7 with the incoming microwaves;

[0057] See also Figure 2In one embodiment of the present invention, the substrate cooling water table group 13 includes an outer cooling water jacket 131 and an inner cooling water table 133 movably arranged on the outer cooling water jacket 131, a wafer 8 is placed on the inner cooling water table 133, and the placed wafer 8 is used for chemical vapor deposition; the inner cooling water table 133 is at least partially located inside the plasma chamber 7, and is arranged opposite to the lateral probe part 42; at the same time, the lower part of the inner cooling water table 133 passes through the opening behind the lower short-circuit plate 11 and extends out of the plasma chamber 7; in addition, a cooling pipeline 132 is provided inside the outer cooling water jacket 131, and a cooling medium flows inside the cooling pipeline 132, and water can be selected as the cooling medium, and its circulation cooling can also be achieved through a pump body;

[0058] In the embodiment of the present invention, the inner cooling water table 133 of the substrate cooling water table group 13 is used to place the wafer 8 for chemical vapor deposition; when the wafer 8 is subjected to chemical vapor deposition, the cooling water can be circulated by a pump through the cooling pipeline 132 arranged inside the outer cooling water jacket 131, so as to achieve cooling and temperature reduction of the entire substrate cooling water table group 13 when processing the wafer 8;

[0059] See also Figure 2 In the embodiment of the present invention, upper threaded rods 1 are symmetrically installed on an upper short-circuit plate 14 movably installed at the upper end of the side wall; lower threaded rods 12 are symmetrically installed on a lower short-circuit plate 11 movably installed at the lower end of the side wall; the upper threaded rods 1 have the same function as the lower threaded rods 12, both of which are to push the upper short-circuit plate 14 or the lower short-circuit plate 11 to slide along the side walls on both sides of the plasma chamber 7; at the same time, a flange end 9 is provided on the outer side of the movable lower short-circuit plate 11, and the lower end of the flange end 9 is fixed to the furnace tube 2 through a flange tube 10;

[0060] For example, the distance between the upper short-circuit plate 14 and the lower short-circuit plate 11 is set to L1, and the distance between the lateral probe portion 42 and the outer cooling water jacket 131 is set to L2;

[0061] In the process of pushing the upper short-circuit plate 14 and the lower short-circuit plate 11 closer to each other or the process of the lateral probe part 42 and the outer cooling water jacket 131 closer to each other, the distance position adjustment of L1 or L2 is reduced, and then the enclosed space of the plasma chamber 7 can be compressed as a whole, so that it is easy to adjust the impedance inside the plasma chamber 7 to maximize the absorption of microwaves, form a stronger electromagnetic field center area inside the plasma chamber 7, ionize the gas, form plasma, and then form more solid matter deposition on the surface of the wafer 8;

[0062] When the lateral probe 42 and the outer cooling water jacket 131 are pushed to separate from each other, the position of L2 is expanded, which can better realize the plasma away from the microwave window 5, and can effectively prevent the window from becoming black and overheating after the plasma cavity 7 is operated for a long time, thereby reducing the efficiency of microwave transmission to the plasma body and the plasma etching the window during operation, resulting in the release of impurity silicon and affecting the growth quality of the deposited material on the surface of the wafer 8;

[0063] When the lower short-circuit plate 11 is pushed to slide along the side wall of the plasma chamber 7, the flange end 9 can be provided to limit the sliding displacement of the lower short-circuit plate 11, thereby ensuring that the lower short-circuit plate 11 is not easily displaced during the sliding displacement.

[0064] See also Figure 3 and Figure 4 In one embodiment of the present invention, the two sides of the bottom end of the gas disk 15 are symmetrically connected to the air intake riser 16 and the temporary air riser 19, and the lower ends of the air intake riser 16 and the temporary air riser 19 are both passed through the flange ends 9 symmetrically distributed inside the plasma chamber 7; at the same time, the lower end of the air intake riser 16 is provided with an end 17, and one end of the end 17 is connected to the bellows 18;

[0065] In the embodiment of the present invention, the provided gas inlet riser 16 and the temporary gas riser 19 have the same function, both of which are to support the placed gas disk 15, and ensure that the gas disk 15 located inside the plasma chamber 7 is distributed in a ring shape at the upper end surface of the wafer 8;

[0066] The gas inlet riser 16 has other functions. For example, when the raw material gas is introduced through the bellows 18, it enters along the gas inlet riser 16 and finally diffuses out from the lower end of the gas plate 15 to provide raw material gas for chemical vapor deposition of the wafer 8. The bellows 18 designed in a corrugated shape can adjust and change the gas inlet direction of the raw material gas according to the installation requirements.

[0067] The temporary gas riser 19 also has other functions. In addition to supporting the gas disk 15, it can also temporarily store part of the gas to ensure that the pressure of the gas input into the gas disk 15 is consistent.

[0068] Furthermore, a tray 21 is provided at the lower end of the inner wall of the gas disk 15, and a diffuser pipe 20 is installed on the tray 21 in an annular distribution, and the installed diffuser pipe 20 is connected to the inside of the gas disk 15;

[0069] The annularly distributed diffuser 20 can uniformly increase the pressure and speed of the raw material gas entering the gas disk 15 and then discharge it, and evenly cover the upper surface of the wafer 8 in multiple directions and angles, so as to improve the quality of the deposited material when the wafer 8 is subjected to chemical vapor deposition;

[0070] See also Figure 5Specifically, in the embodiment of the present invention, a pressure diffuser chamber 24 is formed inside the pressure diffuser tube 20, an air inlet 22 is provided at one end of the pressure diffuser chamber 24, and an exhaust port 25 is provided at the other end of the pressure diffuser chamber 24, and the diameter of the exhaust port 25 is smaller than the diameter of the air inlet 22; at the same time, a valve plate 23 is movably installed in the pressure diffuser chamber 24 at the position where the air inlet 22 is provided;

[0071] When the raw gas entering the gas disk 15 is discharged, the gas pressure of the raw gas can push the valve plate 23 to flip inside the pressure diffusion chamber 24, and then the gas inlet 22 can be opened to allow the raw gas to enter the pressure diffusion chamber 24. The continuous entry of the raw gas can keep the valve plate 23 in an open state.

[0072] After the raw gas enters the pressure diffuser chamber 24, it is temporarily stored inside the pressure diffuser chamber 24 and then discharged through the exhaust port 25. Since the diameter of the exhaust port 25 is smaller than that of the air inlet 22, the gas discharged from the exhaust port 25 can be discharged after being pressurized and accelerated.

[0073] After the supply of raw material gas stops in the later stage, the valve plate 23 is set under the action of its own gravity and the pressure difference between the inside of the plasma chamber 7 and the outside (the pressure inside the plasma chamber 7 is greater than the outside pressure), so that the valve plate 23 can be restored to the initial state, which is used to block the position of the air inlet 22, and constitute the function of a one-way valve, which can prevent the reaction gas inside the plasma chamber 7 from returning to the inside of the gas disk 15 and being discharged in the reverse direction along the input pipeline, thereby reducing the loss of raw material gas and preventing the remaining chemical deposition reaction from being difficult to continue due to insufficient loss of raw material gas; at the same time, the raw material gas is high-temperature gas at this time, and if the raw material gas returns, it will cause heat loss;

[0074] Example 2

[0075] See also Figure 6 , a microwave plasma chemical vapor deposition device provided in Example 2 of the present invention, the microwave plasma chemical vapor deposition device comprises:

[0076] A furnace tube 2, wherein the furnace tube 2 is used to perform chemical vapor deposition on a wafer 8 placed therein by microwaves; wherein a plasma chamber 7 is formed inside the furnace tube 2, and the formed plasma chamber 7 includes an upper short-circuit plate 14, a side wall, and a lower short-circuit plate 11;

[0077] The upper short-circuit plate 14 is movably mounted on the upper end of the side wall, and an opening is provided in the middle of the upper short-circuit plate 14, and the opening is used to introduce microwaves; the lower short-circuit plate 11 is movably mounted on the lower end of the side wall;

[0078] A waveguide 3 is mounted on the upper short-circuit plate 14, and the waveguide 3 is located above the opening in the middle of the upper short-circuit plate 14; the bottom end of the waveguide 3 is connected to the upper short-circuit plate 14, and the waveguide 3 is used to introduce the microwave into the opening; for the waveguide 3, suitable metals such as stainless steel or aluminum are used; but in order to reduce the transmission loss of microwaves, the inner surface is preferably plated with a metal with a low resistivity, such as gold, silver or copper; the frequency band wavelength of the microwaves is not limited here, as long as they have a wavelength that can generate plasma; an excitation probe 4 is provided inside the opening, and the excitation probe 4 is used to introduce the microwave into the plasma cavity 7; a microwave window 5 is also provided between the lower end of the upper short-circuit plate 14 and the excitation probe 4, and the microwave window 5 is also used to introduce the microwave into the plasma cavity 7 and keep the inside of the plasma cavity 7 at a preset vacuum, and the microwave window 5 is made of quartz or a material that can make microwaves transparent;

[0079] A substrate cooling water table group 13 is provided above the lower short-circuit plate 11, and a wafer 8 is placed on the upper end of the substrate cooling water table group 13; the wafer 8 is located between the excitation probe 4 and the substrate cooling water table group 13; the placed wafer 8 is used for chemical vapor deposition to produce solid substances on its surface; at the same time, the inner wall of the plasma chamber 7 is symmetrically and evenly connected to the diffuser pipes 20 for air intake; the diffuser pipe 20 is used to uniformly and multi-angle-directedly provide raw material gas to the upper end surface of the wafer 8 when the wafer 8 is chemically deposited, and can also avoid gas leakage inside the plasma chamber 7 when the gas supply is stopped, reduce the gas pressure, and affect the generation of deposited substances on the surface of the wafer 8 in the later stage; the raw material gas includes a first raw material gas and a second raw material gas, the first raw material gas is at least one of hydrogen, helium and argon; the second raw material gas is hydrocarbon gas or hydrocarbon gas and oxygen-containing gas (such as O 2 ,CO,CO 2 ), nitrogen-containing gases (such as N 2 NH 3 ,NO,NO 2 ), Boron-containing gas (BF 3 , BCl 3 , B 2 H 6 , C 6 H 15 B.C 3 H 9 B), phosphorus-containing gases (such as P 4 PF 3 PF 5 , PH 3 ) a mixture of at least one of ;

[0080] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microwave plasma chemical vapor deposition device, comprising: A furnace tube (2), wherein a plasma chamber (7) is formed inside the furnace tube (2), the formed plasma chamber (7) comprising an upper short-circuit plate (14), a side wall and a lower short-circuit plate (11); the upper short-circuit plate (14) is movably mounted on the upper end of the side wall, and an opening is provided at the middle of the upper short-circuit plate (14); the lower short-circuit plate (11) is movably mounted on the lower end of the side wall; the characteristics are: A waveguide (3) is mounted on the upper short-circuit plate (14), and the bottom end of the waveguide (3) is connected to the upper short-circuit plate (14); an excitation probe (4) is provided inside the opening, and a microwave window (5) is also provided between the lower end of the upper short-circuit plate (14) and the excitation probe (4); A substrate cooling water table group (13) is provided above the lower short-circuit plate (11), and a wafer (8) is placed on the upper end of the substrate cooling water table group (13); at the same time, a gas disk (15) is provided on the outer side of the upper end of the wafer (8), which is used to uniformly supply raw material gas to the upper end surface of the wafer (8) in multiple angles when the wafer (8) is chemically deposited, and can also prevent gas leakage inside the plasma chamber (7) when the gas supply is stopped, reduce gas pressure, and affect the generation of deposited materials on the surface of the wafer (8) in the later stage.

2. The microwave plasma chemical vapor deposition equipment according to claim 1, characterized in that: The excitation probe (4) is a water-cooled excitation probe, comprising a longitudinal probe portion (41) and a transverse probe portion (42), wherein the longitudinal probe portion (41) is arranged at the center of the waveguide (3), and the end of the longitudinal probe portion (41) extends into the interior of the plasma chamber (7); and the transverse probe portion (42) is annular and is located at the end of the longitudinal probe portion (41).

3. The microwave plasma chemical vapor deposition equipment according to claim 1, characterized in that: The substrate cooling water table group (13) comprises an outer cooling water jacket (131) and an inner cooling water table (133) movably arranged on the outer cooling water jacket (131); the inner cooling water table (133) is at least partially located inside the plasma chamber (7) and arranged opposite to the transverse probe portion (42); the lower portion of the inner cooling water table (133) passes through the opening behind the lower short-circuit plate (11) and extends out of the plasma chamber (7); in addition, a cooling pipeline (132) is arranged inside the outer cooling water jacket (131), and a cooling medium flows inside the cooling pipeline (132).

4. The microwave plasma chemical vapor deposition equipment according to claim 1, characterized in that: An upper short-circuit plate (14) movably mounted at the upper end of the side wall is symmetrically mounted with upper threaded rods (1); a lower short-circuit plate (11) movably mounted at the lower end of the side wall is symmetrically mounted with lower threaded rods (12); and a flange end (9) is provided on the outer side of the movably displaceable lower short-circuit plate (11), and the lower end of the flange end (9) is mounted and fixed on the furnace tube (2) via a flange pipe (10).

5. The microwave plasma chemical vapor deposition equipment according to claim 4, characterized in that: The two sides of the bottom end of the gas disk (15) are symmetrically connected to the air intake riser (16) and the temporary air riser (19), and the lower ends of the air intake riser (16) and the temporary air riser (19) are both arranged to pass through the flange ends (9) symmetrically distributed inside the plasma chamber (7); at the same time, the lower end of the air intake riser (16) is provided with an end head (17), and one end of the end head (17) is connected to the bellows (18).

6. The microwave plasma chemical vapor deposition equipment according to claim 5, characterized in that: A tray (21) is provided at the lower end of the inner wall of the gas disk (15), and diffuser pipes (20) are installed on the tray (21) in an annular distribution. The installed diffuser pipes (20) are connected to the inside of the gas disk (15).

7. The microwave plasma chemical vapor deposition equipment according to claim 6, characterized in that: A pressure diffuser chamber (24) is formed inside the pressure diffuser tube (20), an air inlet (22) is provided at one end of the pressure diffuser chamber (24), and an exhaust port (25) is provided at the other end of the pressure diffuser chamber (24), wherein the diameter of the exhaust port (25) is smaller than the diameter of the air inlet (22); and a valve plate (23) is movably installed in the pressure diffuser chamber (24) at the position where the air inlet (22) is provided.

8. A microwave plasma chemical vapor deposition device, comprising: A furnace tube (2), wherein a plasma chamber (7) is formed inside the furnace tube (2), the formed plasma chamber (7) comprising an upper short-circuit plate (14), a side wall and a lower short-circuit plate (11); the upper short-circuit plate (14) is movably mounted on the upper end of the side wall, and an opening is provided at the middle of the upper short-circuit plate (14); the lower short-circuit plate (11) is movably mounted on the lower end of the side wall; the characteristics are: A waveguide (3) is mounted on the upper short-circuit plate (14), and the bottom end of the waveguide (3) is connected to the upper short-circuit plate (14); an excitation probe (4) is provided inside the opening, and a microwave window (5) is provided between the lower end of the upper short-circuit plate (14) and the excitation probe (4); a substrate cooling water table group (13) is provided above the lower short-circuit plate (11), and a wafer (8) is placed on the upper end of the substrate cooling water table group (13); At the same time, a diffuser tube (20) is symmetrically and evenly distributed on the inner wall of the plasma chamber (7) for evenly supplying raw material gas to the upper surface of the wafer in multiple angles when the wafer is chemically deposited. When the gas supply is stopped, the diffuser tube can also avoid gas leakage inside the plasma chamber, reduce gas pressure, and affect the generation of deposited material on the wafer surface in the later stage.

Images