Polycrystalline silicon low-pressure chemical vapor deposition reaction device beneficial to prolonging maintenance period

Abstract

According to the polycrystalline silicon low-pressure chemical vapor deposition reaction device beneficial to prolonging the maintenance period, the bottom of a reaction outer pipe is in sealed connection with a flange connecting piece, and the side portion of the flange connecting piece is in sealed connection with a gas inlet header pipe and a vacuumizing assembly; the inner reaction pipe, the first gas inlet pipe, the second gas inlet pipe and the third gas inlet pipe are all fixedly arranged in the flange connecting piece, the inner reaction pipe is nested on the inner side of the outer reaction pipe, the three gas inlet pipes all extend to a reaction area in the inner reaction pipe along the vertical direction, and gas outlet holes of the three gas inlet pipes are respectively positioned at positions with different heights in the inner reaction pipe. The device has the advantages of being compact in structure, simple in principle, high in operation stability and the like, on the premise that reliable sealing work of the reaction tube is guaranteed, the uniformity of gas in the reaction tube is improved, particle pollution in the polycrystalline silicon thin film deposition process is reduced, the maintenance period of equipment is effectively prolonged, and the normal process time of the equipment is remarkably prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer processing thin film deposition equipment, and in particular relates to a polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle. Background Art

[0002] Polysilicon low-pressure chemical vapor deposition technology is a major method for polysilicon thin film deposition in integrated circuit manufacturing. This method is carried out in a reaction tube, and special gases enter the reaction tube through an inlet pipe. In a low-pressure, high-temperature environment, chemical reactions occur and are deposited on the surface of the wafer to form a thin film.

[0003] During the implementation of the existing polysilicon low-pressure chemical vapor deposition process, the reactants in the reaction tube will also be deposited on the quartz parts, pipeline surfaces, etc., causing particle pollution and affecting product quality. Therefore, it is necessary to shut down the equipment regularly before the particle pollution exceeds the standard to clean the equipment reaction chamber, quartz parts, pipelines and other components and carriers, and resume production after the re-machine test is qualified. Particle pollution directly affects the maintenance cycle, which directly affects the effective normal process time of the equipment and is the core performance indicator of polysilicon low-pressure chemical vapor deposition equipment. Frequent maintenance work will increase maintenance and hardware costs and affect the effective output of the equipment. Therefore, a new reaction chamber device is urgently needed to reduce particle pollution, extend the maintenance cycle, and increase the effective normal process time of the equipment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a polysilicon low-pressure chemical vapor deposition reaction device with a compact structure, simple principle, high operating stability and conducive to reducing particle pollution and extending the maintenance cycle in view of the deficiencies in the prior art.

[0005] To achieve the above object, the present invention can adopt the following technical solutions:

[0006] A polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle, comprising: an outer reaction tube, an inner reaction tube, a first air inlet pipe, a second air inlet pipe, a third air inlet pipe, a flange connection, and a vacuum pumping assembly;

[0007] The bottom of the outer reaction tube is sealed with the flange connector, and the sides of the flange connector are respectively sealed with the air intake manifold and the vacuum pumping assembly, the inner reaction tube, the first air intake pipe, the second air intake pipe and the third air intake pipe are all installed and fixed inside the flange connector, and the inner reaction tube is nested inside the outer reaction tube, and a sealed polysilicon deposition area is formed inside the inner reaction tube, the first air intake pipe, the second air intake pipe and the third air intake pipe all extend in the vertical direction to the reaction area inside the inner reaction tube, and the air outlets of the first air intake pipe, the second air intake pipe and the third air intake pipe are respectively located at different heights inside the inner reaction tube.

[0008] As a further improvement of the present invention, the first air inlet pipe is a square tube with two ends connected, and the open end at the top of the first air inlet pipe is close to the upper part of the reaction inner tube.

[0009] As a further improvement of the present invention, the second air inlet pipe is a square tube with one end closed, and the closed end at the top of the second air inlet pipe is close to the upper part of the reaction inner tube, and multiple rows of first air outlet holes are symmetrically provided on both sides of the second air inlet pipe.

[0010] As a further improvement of the present invention, multiple rows of first air outlet holes are arranged in sequence from the top to the middle of the second air inlet pipe downward, and the hole spacing increases from top to bottom.

[0011] As a further improvement of the present invention, the third air inlet pipe is a square tube with a closed top, and the length of the third air inlet pipe is smaller than that of the first air inlet pipe. Multiple rows of second air outlet holes are symmetrically provided on both sides of the third air inlet pipe.

[0012] As a further improvement of the present invention, multiple rows of second air outlet holes are arranged in sequence from the top to the middle of the third air inlet pipe downward, and the hole spacing increases in sequence from top to bottom.

[0013] As a further improvement of the present invention, the wall thickness of the first air inlet pipe, the second air inlet pipe and the third air inlet pipe are all 2 mm to 7 mm; the apertures of the first air outlet and the second air outlet are 3 mm to 5 mm; the length of the first air inlet pipe is L, and the length of the third air inlet pipe is H=(1 / 3~2 / 3)L.

[0014] As a further improvement of the present invention, the materials of the inner reaction tube, the first air inlet pipe, the second air inlet pipe and the third air inlet pipe are all silicon carbide, silicon or quartz.

[0015] As a further improvement of the present invention, the top of the reaction inner tube is closed, and the reaction gas is fed into the reaction inner tube through the first air inlet pipe, the second air inlet pipe and the third air inlet pipe. The air flow direction in the reaction inner tube is from top to bottom and is discharged through the vacuum pumping component.

[0016] As a further improvement of the present invention, the vacuum pumping assembly includes an exhaust pipe and a vacuum pump, one end of the exhaust pipe is sealedly connected to the flange connector, and the other end of the exhaust pipe is sealedly connected to the vacuum pump.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] The polysilicon low-pressure chemical vapor deposition reaction device of the present invention is beneficial to extending the maintenance cycle. The bottom of the outer reaction tube is sealed and connected with the flange connector, and the side of the flange connector is sealed and connected with the air intake main pipe and the vacuum pumping component respectively, so that the process gas is introduced into the reaction chamber or the vacuum is pumped through the flange connector; the inner reaction tube, the first air intake pipe, the second air intake pipe and the third air intake pipe are all installed and fixed inside the flange connector, and the inner reaction tube is nested inside the outer reaction tube, the first air intake pipe, the second air intake pipe and the third air intake pipe are arranged inside the inner reaction tube, and the air outlets of the three air intake pipes are respectively located at different heights inside the inner reaction tube, and extend to the reaction area inside the inner reaction tube in the vertical direction. The top of the inner reaction tube is closed and nested and fixed inside the outer reaction tube. The inner reaction tube forms a polysilicon deposition reaction area, and the airflow direction in the inner reaction tube is from top to bottom. In view of the characteristics of low-pressure chemical vapor deposition of polysilicon, the uniformity of the gas flow field of the process gas in the reaction area is improved by optimizing the design of the reaction inner tube and the air inlet structure and the material selection, which effectively reduces the particle contamination in the polysilicon deposition process, significantly extends the maintenance cycle of the equipment, and increases the cumulative film thickness of continuous normal deposition by 5 to 10 times, significantly extending the normal process time of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structural principle of a polysilicon low-pressure chemical vapor deposition reaction device that is beneficial for extending the maintenance cycle in a specific embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the three-dimensional structure principle of the first air intake pipe in a specific embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the main structural principle of the first air intake pipe in a specific embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of the three-dimensional structure principle of the second air intake pipe in a specific embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the main structural principle of the second air intake pipe in a specific embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the main structural principle of the third air intake pipe in a specific embodiment of the present invention;

[0025] Legend: 1. Reaction outer tube; 2. Reaction inner tube; 3. First air inlet pipe; 4. Process gas; 5. Second air inlet pipe; 6. Third air inlet pipe; 7. Flange connector; 8. Exhaust pipe; 9. Vacuum pump; 31. Open end; 51. Closed end; 52. First air outlet; 61. Second air outlet. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0027] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0029] Example

[0030] like Figure 1 As shown, the polysilicon low-pressure chemical vapor deposition reaction device of the present invention, which is beneficial to extending the maintenance cycle, includes: an outer reaction tube 1, an inner reaction tube 2, a first air inlet pipe 3, a second air inlet pipe 5, a third air inlet pipe 6, a flange connector 7 and a vacuum pumping assembly.

[0031] The bottom of the outer reaction tube 1 is sealed with the flange connector 7, and the side of the flange connector 7 is sealed with the gas inlet manifold (not shown in the figure) and the vacuum assembly. The inner reaction tube 2, the first gas inlet pipe 3, the second gas inlet pipe 5 and the third gas inlet pipe 6 are all installed and fixed inside the flange connector 7, and the inner reaction tube 2 is nested inside the outer reaction tube 1, and a sealed polysilicon deposition area is formed inside the inner reaction tube 2. The first gas inlet pipe 3, the second gas inlet pipe 5 and the third gas inlet pipe 6 are all extended to the reaction area inside the inner reaction tube 2 in the vertical direction, and the gas outlets of the first gas inlet pipe 3, the second gas inlet pipe 5 and the third gas inlet pipe 6 are respectively located at different heights inside the inner reaction tube 2, so that the process gas 4 can be introduced into different height areas of the inner reaction tube 2.

[0032] In this embodiment, the bottom of the outer reaction tube 1 is sealed with the flange connector 7, and the side of the flange connector 7 is sealed with the gas inlet manifold and the vacuum assembly, respectively, so that the process gas 4 is introduced into the reaction chamber or the vacuum is drawn through the flange connector 7. The inner reaction tube 2, the first gas inlet pipe 3, the second gas inlet pipe 5 and the third gas inlet pipe 6 are all installed and fixed inside the flange connector 7, the inner reaction tube 2 is nested inside the outer reaction tube 1, and a sealed reaction area is formed inside the inner reaction tube 2. The first gas inlet pipe 3, the second gas inlet pipe 5 and the third gas inlet pipe 6 all extend vertically to the reaction area inside the inner reaction tube 2, and the gas outlets of the three gas inlet pipes are respectively located at different heights inside the inner reaction tube 2. Under the premise of ensuring the reliable operation of the reaction tube seal, the uniformity of the gas flow field of the process gas in the reaction area is improved, and the adhesion and shedding of the process particle pollutants on the inner wall 2 of the reaction tube are reduced, thereby reducing the particle pollution brought to the wafer surface and effectively extending the maintenance cycle of the equipment. The cumulative film thickness of the continuous normal deposition increases by 5 to 10 times, which significantly extends the normal process time of the equipment.

[0033] like Figure 2 and Figure 3 As shown, the first air inlet pipe 3 is a rectangular tube with two ends connected, and the open end 31 at the top of the first air inlet pipe 3 is close to the top of the reaction inner tube 2 to achieve direct delivery of the process gas 4 to the top of the reaction inner tube 2.

[0034] like Figure 4 and Figure 5 As shown, the second air inlet pipe 5 is a rectangular tube with one end closed, and the closed end 51 at the top of the second air inlet pipe 5 is close to the upper part of the inner reaction tube 2, and multiple rows of first air outlet holes 52 are symmetrically provided on both sides of the second air inlet pipe 5.

[0035] Furthermore, multiple rows of first gas outlet holes 52 are arranged downward from the top to the middle of the second gas inlet pipe 5 , and the first gas outlet holes 52 are set on the narrow side of the rectangular tube to achieve direct delivery of the process gas 4 to the middle and upper part of the reaction inner tube 2 .

[0036] like Figure 6 As shown, the third air inlet pipe 6 is a rectangular tube with a closed top, and the length of the third air inlet pipe 6 is less than that of the first air inlet pipe 3 . Two sides of the third air inlet pipe 6 are symmetrically provided with multiple rows of second air outlet holes 61 .

[0037] Furthermore, multiple rows of second gas outlet holes 61 are arranged downward from the top to the middle of the third gas inlet pipe 6 , and the second gas outlet holes 61 are set on the narrow side of the rectangular tube to achieve direct delivery of the process gas 4 to the middle and lower part of the reaction inner tube 2 .

[0038] In this embodiment, the wall thickness of the first air inlet pipe 3, the second air inlet pipe 5 and the third air inlet pipe 6 are all 2 mm to 7 mm; the aperture of the first air outlet 52 and the second air outlet 61 is 3 mm to 5 mm; the length of the first air inlet pipe 3 and the length of the second air inlet pipe 5 are both L, and the length of the third air inlet pipe 6 is H = (1 / 3 to 2 / 3) L. By using three air inlet pipes with different structures, the air flow in the reaction inner tube 2 flows from top to bottom, which improves the uniformity of the air flow field of the process gas in the reaction tube and reduces the adhesion and shedding of particles in the reaction tube.

[0039] In this embodiment, the material of the reaction inner tube 2 is silicon carbide, and the materials of the first air inlet pipe 3, the second air inlet pipe 5 and the third air inlet pipe 6 are all silicon. In other embodiments, the material of the reaction inner tube 2 can also be silicon or quartz, and the material of the first air inlet pipe 3, the second air inlet pipe 5 and the third air inlet pipe 6 can also be silicon carbide or quartz.

[0040] like Figure 1 As shown, the vacuum pumping assembly includes a vacuum pipe 8 and a vacuum pump 9. One end of the vacuum pipe 8 is sealed with the flange connector 7, and the other end of the vacuum pipe 8 is sealed with the vacuum pump 9. The vacuum pumping assembly is arranged outside the reaction tube to form a low-pressure environment inside the reaction tube.

[0041] like Figure 1 As shown, in this embodiment, the top of the reaction inner tube 2 is closed, and the reaction gas is fed into the reaction inner tube 2 by the first air inlet pipe 3, the second air inlet pipe 5 and the third air inlet pipe 6. The air flow direction in the reaction inner tube 2 is from top to bottom and is discharged through the vacuum pump 9.

[0042] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the spirit and technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A polysilicon low-pressure chemical vapor deposition reaction device that is conducive to extending the maintenance cycle, characterized in that: include: An outer reaction tube (1), an inner reaction tube (2), a first air inlet pipe (3), a second air inlet pipe (5), a third air inlet pipe (6), a flange connection (7) and a vacuum pumping assembly; The bottom of the outer reaction tube (1) is sealedly connected to the flange connection piece (7), and the side of the flange connection piece (7) is sealedly connected to the air intake manifold and the vacuum pumping assembly respectively; the inner reaction tube (2), the first air intake pipe (3), the second air intake pipe (5) and the third air intake pipe (6) are all installed and fixed inside the flange connection piece (7), and the inner reaction tube (2) is nested inside the outer reaction tube (1); a sealed polysilicon deposition area is formed inside the inner reaction tube (2); the first air intake pipe (3), the second air intake pipe (5) and the third air intake pipe (6) are all extended in a vertical direction to the reaction area inside the inner reaction tube (2), and the air outlet holes of the first air intake pipe (3), the second air intake pipe (5) and the third air intake pipe (6) are respectively located at different heights inside the inner reaction tube (2).

2. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 1 is characterized in that: The first air inlet pipe (3) is a square tube with a through top, and the open end (31) at the top of the first air inlet pipe (3) is close to the upper part of the inner reaction tube (2).

3. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 2 is characterized in that: The second air inlet pipe (5) is a square tube with a closed top, and the closed end (51) at the top of the second air inlet pipe (5) is close to the upper part of the inner reaction tube (2), and multiple rows of first air outlet holes (52) are symmetrically provided on both sides of the second air inlet pipe (5).

4. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 3 is characterized in that: The multiple rows of first air outlet holes (52) are arranged in sequence from the top to the middle of the second air inlet pipe (5) downward, and the hole spacing increases in sequence from top to bottom.

5. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 4 is characterized in that: The third air inlet pipe (6) is a square tube with a closed top, and the length of the third air inlet pipe (6) is shorter than the length of the first air inlet pipe (3). Two sides of the third air inlet pipe (6) are symmetrically provided with multiple rows of second air outlet holes (61).

6. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 5 is characterized in that: The multiple rows of second air outlet holes (61) are arranged in sequence from the top to the middle of the third air inlet pipe (6) downward, and the hole spacing increases in sequence from top to bottom.

7. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 6 is characterized in that: The wall thickness of the first air inlet pipe (3), the second air inlet pipe (5) and the third air inlet pipe (6) is 2 mm to 7 mm; the aperture of the first air outlet hole (52) and the second air outlet hole (61) is 3 mm to 5 mm; the length of the first air inlet pipe (3) is L, and the length of the third air inlet pipe (6) is H=(1 / 3 to 2 / 3)L.

8. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to any one of claims 1 to 7, characterized in that: The materials of the inner reaction tube (2), the first air inlet pipe (3), the second air inlet pipe (5) and the third air inlet pipe (6) are all silicon carbide, silicon or quartz.

9. The polysilicon low-pressure chemical vapor deposition reaction device that is beneficial to extending the maintenance cycle according to claim 7, characterized in that: The top of the reaction inner tube (2) is sealed, and the reaction gas is fed into the reaction inner tube (2) through the first air inlet pipe (3), the second air inlet pipe (5) and the third air inlet pipe (6), and the air flow direction in the reaction inner tube (2) is from top to bottom and is discharged through the vacuum pumping component.

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