Concentrated exhaust unit and semiconductor process equipment

Abstract

The invention discloses a centralized exhaust unit and semiconductor process equipment, belongs to the technical field of chemical vapor deposition, and aims to solve the problem of poor exhaust smoothness caused by overlarge length of an exhaust pipeline of a vacuum pump in the prior art. The centralized exhaust unit is used for exhaust of process cavities in semiconductor process equipment, the centralized exhaust unit comprises an exhaust fan and a plurality of vacuum pumps, the air outlet ends of the process cavities are connected with the exhaust fan through the vacuum pumps, the process cavities correspond to the vacuum pumps one to one, and the vacuum pumps correspond to the exhaust fan. The method can be used for chemical vapor deposition.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical vapor deposition, and in particular relates to a centralized exhaust unit and semiconductor process equipment. Background Art

[0002] Currently, semiconductor process equipment can be used for the growth of high-grade diamonds and the deposition of diamonds. Semiconductor process equipment generally includes a working gas supply unit, a process chamber, and an exhaust unit connected in sequence.

[0003] During the growth of diamonds, the pressure in the process chamber needs to be strictly regulated and controlled. Changes or fluctuations in the pressure in the process chamber will affect the growth rate, purity and color of diamonds. Among them, the intake flow rate of the working gas (hydrogen, methane and other gases), the exhaust speed of the exhaust unit and the working temperature in the process chamber will affect the pressure in the process chamber.

[0004] At present, vacuum pumps are usually used as exhaust units. The process chamber corresponds to the vacuum pump one by one. The exhaust pipelines of the vacuum pumps are uniformly collected and discharged to the outside. The pressure in the process chamber is controlled by adjusting the pumping speed of the vacuum pump.

[0005] However, when the number of process chambers is large, the length of the exhaust pipeline of the vacuum pump will be greatly increased, affecting the smoothness of the exhaust. Summary of the invention

[0006] In view of the above analysis, the present invention aims to provide a centralized exhaust unit and semiconductor process equipment to solve the problem in the prior art that the exhaust pipeline of the vacuum pump is too long, resulting in poor exhaust smoothness.

[0007] The purpose of the present invention is mainly achieved through the following technical solutions.

[0008] The present invention provides a centralized exhaust unit for exhausting a process chamber in semiconductor process equipment. The centralized exhaust unit comprises an exhaust fan and multiple vacuum pumps. The gas outlet end of the process chamber is connected to the exhaust fan through the vacuum pump. The process chamber corresponds to the vacuum pump one by one, and multiple vacuum pumps correspond to one exhaust fan.

[0009] Furthermore, the centralized exhaust unit further includes an exhaust pipeline, and a plurality of vacuum pumps are connected to the exhaust fan via the exhaust pipeline.

[0010] Furthermore, the exhaust pipeline includes an exhaust main pipe and multiple exhaust branch pipes, one end of the exhaust branch pipe is connected to the air outlet of the vacuum pump, the other end of the exhaust branch pipe is connected to the exhaust main pipe, and the air outlet end of the exhaust main pipe is connected to the exhaust fan.

[0011] Furthermore, the exhaust branch pipes correspond to the vacuum pumps one by one.

[0012] Furthermore, the centralized exhaust unit further comprises a main pipe pressure sensor and a fan controller, the fan controller is connected to the main pipe pressure sensor and the exhaust fan respectively, and the main pipe pressure sensor is arranged in the exhaust pipe.

[0013] Furthermore, the above-mentioned centralized exhaust unit also includes a cavity pressure sensor, a pre-flow regulating valve and a pre-flow controller. The cavity pressure sensor is arranged in the process cavity, the pre-flow regulating valve is arranged on the connecting pipeline between the process cavity and the vacuum pump, and the pre-flow controller is respectively connected to the cavity pressure sensor and the pre-flow regulating valve.

[0014] Furthermore, the above-mentioned centralized exhaust unit also includes a branch pipe pressure sensor, a post-flow regulating valve and a post-flow controller. The branch pipe pressure sensor is arranged in the exhaust branch pipe, the post-flow regulating valve is arranged on the exhaust branch pipe, and the post-flow controller is respectively connected to the branch pipe pressure sensor and the post-flow regulating valve.

[0015] Furthermore, along the gas flow direction, the branch pipe pressure sensor is located before the post-flow regulating valve.

[0016] Furthermore, the number of process chambers and vacuum pumps is 4 to 6.

[0017] The present invention also provides a semiconductor process equipment, comprising a working gas supply unit, a process chamber and a centralized exhaust unit connected in sequence, wherein the centralized exhaust unit is the centralized exhaust unit provided above.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0019] A) The centralized exhaust unit provided by the present invention has an exhaust fan specially used for exhausting air at the rear end of the vacuum pump. The vacuum pump can promote the gas in the process chamber to flow out of the process chamber. The exhaust fan can further improve the power of gas flow, making it convenient for the gas to be discharged to the outside from the connecting pipeline between the vacuum pump and the exhaust fan in time, thereby improving the smoothness of exhaust.

[0020] B) The centralized exhaust unit provided by the present invention can effectively simplify the overall structure of the centralized exhaust unit because multiple vacuum pumps correspond to one exhaust fan.

[0021] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0023] Figure 1 A schematic structural diagram of a centralized exhaust unit provided in Embodiment 1 of the present invention is provided;

[0024] Figure 2 A schematic diagram of the structure of a semiconductor process equipment provided in Embodiment 2 of the present invention is provided;

[0025] Figure 3 A schematic diagram of the structure of a cavity connecting pipeline in a semiconductor process equipment provided in Embodiment 2 of the present invention is provided, wherein the thermal expansion protrusion is not in contact with the contact sensor;

[0026] Figure 4 A schematic diagram of the structure of a cavity connecting pipeline in a semiconductor process equipment provided in Embodiment 2 of the present invention is provided, wherein the thermal expansion protrusion contacts the contact sensor;

[0027] Figure 5 A schematic structural diagram of a process chamber and a preheating pipeline in a semiconductor process equipment provided in Embodiment 2 of the present invention is provided.

[0028] Reference numerals:

[0029] 1-process cavity; 101-heat-conducting inner cavity; 102-insulating outer shell; 103-heating body; 104-bracket; 2-cavity connecting pipeline; 201-contact sensor; 202-inner cylinder; 203-outer cylinder; 204-thermal expansion and contraction ring; 3-exhaust fan; 4-vacuum pump; 5-main pipe pressure sensor; 6-fan controller; 7-cavity pressure sensor; 8-front flow regulating valve; 9-front flow controller; 10-branch pipe pressure sensor; 11-rear flow regulating valve; 12-rear flow controller; 13-exhaust main pipe; 14-exhaust branch pipe; 15-working gas supply unit; 16-preheating cavity; 17-substrate; 18-first constant diameter section; 19-spherical cavity section; 20-second constant diameter section; 21-insulating outer tube. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0031] Embodiment 1

[0032] This embodiment provides a centralized exhaust unit. Figure 1, used for exhausting a process chamber 1 in a semiconductor process equipment, comprising an exhaust fan 3 (e.g., a variable frequency fan) and a plurality of vacuum pumps 4, the gas outlet end of the process chamber 1 is connected to the exhaust fan 3 through the vacuum pump 4, the process chamber 1 corresponds to the vacuum pump 4 one by one, and a plurality of vacuum pumps 4 correspond to one exhaust fan 3.

[0033] Compared with the prior art, the centralized exhaust unit provided in this embodiment is provided with an exhaust fan 3 specially used for exhaust at the rear end of the vacuum pump 4. The vacuum pump 4 can promote the gas in the process chamber 1 to flow out of the process chamber 1. The exhaust fan 3 can further improve the power of gas flow, and facilitate the gas to be discharged to the outside from the connecting pipeline between the vacuum pump 4 and the exhaust fan 3 in time, thereby improving the smoothness of exhaust. At the same time, since multiple vacuum pumps 4 correspond to one exhaust fan 3, the overall structure of the centralized exhaust unit can be effectively simplified.

[0034] It should be noted that in practical applications, since the working gas flow rate at the air inlet of the process chamber 1 remains basically unchanged, the pumping speed of the vacuum pump 4 needs to be adjusted according to the temperature in the process chamber 1 to ensure the stability of the pressure in the process chamber 1.

[0035] Exemplarily, from the perspective of layout, the number of the process chambers 1 and vacuum pumps 4 is 4 to 6, that is, 4 to 6 vacuum pumps 4 correspond to one exhaust fan 3 .

[0036] It is understandable that, in order to realize the connection between multiple vacuum pumps 4 and one exhaust fan 3, the above-mentioned centralized exhaust unit also includes an exhaust pipeline, and the multiple vacuum pumps 4 are connected to the exhaust fan 3 through the exhaust pipeline.

[0037] Exemplarily, the exhaust pipe includes an exhaust main pipe 13 and a plurality of exhaust branch pipes 14, the exhaust branch pipes 14 correspond to the vacuum pumps 4 one by one, one end of the exhaust branch pipe 14 is connected to the air outlet of the vacuum pump 4, the other end of the exhaust branch pipe 14 is connected to the exhaust main pipe 13, and the air outlet of the exhaust main pipe 13 is connected to the exhaust fan 3. The exhaust pipe with such a structure can further improve the exhaust smoothness of the centralized exhaust unit.

[0038] In order to automatically adjust the fan speed of the exhaust fan 3 according to the pressure in the exhaust pipe 13, the above-mentioned centralized exhaust unit also includes a main pipe pressure sensor 5 and a fan controller 6. The fan controller 6 is connected to the main pipe pressure sensor 5 and the exhaust fan 3 respectively. The main pipe pressure sensor 5 is arranged in the exhaust pipe 13.

[0039] During implementation, the main pressure sensor 5 detects the main air pressure data in the exhaust main pipe 13 in real time and transmits it to the fan controller 6. The exhaust controller receives the main air pressure data and determines whether the main air pressure data is within the main air pressure threshold range. If the main air pressure data is lower than the main air pressure threshold range, it means that the air pressure in the process chamber 1 has decreased. Then the fan controller 6 controls the exhaust fan 3 to reduce its speed. If the main air pressure data is higher than the main air pressure threshold range, it means that the air pressure in the process chamber 1 has decreased. Then the fan controller 6 controls the exhaust fan 3 to increase its speed. If the main air pressure data is within the main air pressure threshold range, it means that the air pressure in the process chamber 1 is relatively stable. Then the fan controller 6 controls the exhaust fan 3 to keep its speed unchanged. In this way, the air pressure in the exhaust main pipe 13 can be monitored in real time through the main pressure sensor 5 and the fan controller 6. The speed of the exhaust fan 3 is adjusted in real time according to the air pressure, which can not only ensure the smooth discharge of the gas in the exhaust main pipe 13, but also ensure the stability of the air pressure in the exhaust main pipe 13.

[0040] Taking into account that the exhaust of the vacuum pump 4 will directly affect the pressure in the process chamber 1, in order to ensure the accuracy of pressure control in the process chamber 1, the above-mentioned centralized exhaust unit also includes a chamber pressure sensor 7, a pre-flow regulating valve 8 (for example, an electric regulating valve) and a pre-flow controller 9. The chamber pressure sensor 7 is arranged in the process chamber 1, and the pre-flow regulating valve 8 is arranged on the connecting pipeline between the process chamber 1 and the vacuum pump 4. The pre-flow controller 9 is respectively connected to the chamber pressure sensor 7 and the pre-flow regulating valve 8.

[0041] During implementation, the cavity pressure sensor 7 detects the cavity pressure data in the process cavity 1 in real time and transmits it to the pre-flow controller 9. The pre-flow controller 9 receives the cavity pressure data and determines whether the cavity pressure data is within the cavity pressure threshold range. If the cavity pressure data is lower than the cavity pressure threshold range, the pre-flow controller 9 controls the opening of the pre-flow regulating valve 8 to decrease. If the cavity pressure data is higher than the cavity pressure threshold range, the pre-flow controller 9 controls the opening of the pre-flow regulating valve 8 to increase. If the cavity pressure data is within the cavity pressure threshold range, the pre-flow controller 9 controls the opening of the pre-flow regulating valve 8 to remain unchanged. In this way, by adjusting the opening of the pre-flow regulating valve 8, the pressure in the process cavity 1 can be adjusted to ensure the pressure stability in the process cavity 1.

[0042] Correspondingly, the above-mentioned centralized exhaust unit also includes a branch pipe pressure sensor 10, a post-flow regulating valve 11 and a post-flow controller 12. The branch pipe pressure sensor 10 is arranged in the exhaust branch pipe 14, and the post-flow regulating valve 11 is arranged on the exhaust branch pipe 14. Along the gas flow direction, the branch pipe pressure sensor 10 is located in front of the post-flow regulating valve 11, and the post-flow controller 12 is respectively connected to the branch pipe pressure sensor 10 and the post-flow regulating valve 11.

[0043] During implementation, the branch pressure sensor 10 detects the branch pressure data in the exhaust branch pipe 14 in real time and transmits it to the post-flow controller 12. The post-flow controller 12 receives the branch pressure data and determines whether the branch pressure data is within the branch pressure threshold range. If the branch pressure data is lower than the branch pressure threshold range, the post-flow controller 12 controls the opening of the post-flow regulating valve 11 to decrease. If the branch pressure data is higher than the branch pressure threshold range, the post-flow controller 12 controls the opening of the post-flow regulating valve 11 to increase. If the branch pressure data is within the branch pressure threshold range, the post-flow controller 12 controls the opening of the post-flow regulating valve 11 to remain unchanged. In this way, by adjusting the opening of the post-flow regulating valve 11, the pressure in the exhaust branch pipe 14 can be adjusted to ensure the pressure stability in the exhaust branch pipe 14.

[0044] It should be noted that, from the perspective of pressure regulation in the process chamber 1, the above-mentioned main pressure sensor 5, fan controller 6, cavity pressure sensor 7, front flow regulating valve 8, front flow controller 9, branch pipe pressure sensor 10, rear flow regulating valve 11 and rear flow controller 12 are set at the same time to perform pressure detection and regulation from multiple aspects, further improve the exhaust smoothness of the centralized exhaust unit, and ensure the pressure stability in the process chamber 1.

[0045] Embodiment 2

[0046] This embodiment provides a semiconductor process equipment. Figure 2 , including a working gas supply unit 15, a process chamber 1 and a centralized exhaust unit connected in sequence, and the centralized exhaust unit is the centralized exhaust unit provided in Example 1.

[0047] Compared with the prior art, the beneficial effects of the semiconductor process equipment provided in this embodiment are substantially the same as the beneficial effects of the centralized exhaust unit provided in the first embodiment, and are not described in detail here.

[0048] During the semiconductor process, it is necessary to continuously supply working gas into the process chamber 1. However, due to the low storage temperature of the working gas, direct supply will cause the temperature in the process chamber 1 to drop suddenly, which is not conducive to maintaining the temperature stability and pressure stability in the process chamber 1. Therefore, the following two methods can be used to preheat the working gas.

[0049] In one embodiment, the semiconductor process equipment further comprises a preheating chamber 16, and the working gas supply unit 15 is connected to the process chamber 1 through the preheating chamber 16. Exemplarily, the temperature of the process chamber 1 is 800-1000°C, and the temperature of the preheating chamber 16 is 700-780°C.

[0050] It is understandable that in order to achieve the connection between the preheating chamber 16 and the process chamber 1 , the semiconductor process equipment further includes a chamber connecting pipeline 2 , and the preheating chamber 16 is connected to the process chamber 1 through the chamber connecting pipeline 2 .

[0051] Considering that the temperature of the preheating chamber 16 is very close to the process chamber 1, the working temperature may be too high at the position of the chamber connecting pipeline 2 close to the process chamber 1, and the working gas with too high temperature may react and deposit in the chamber connecting pipeline 2. In order to avoid the above situation, the structure of the chamber connecting pipeline 2, specifically, includes an inner cylinder 202 and an outer cylinder 203 sleeved outside the inner cylinder 202, and there is a gap between the inner cylinder 202 and the outer cylinder 203. The outer wall of the inner cylinder 202 is provided with a thermal expansion protrusion 204, and the thermal expansion protrusion 204 has a large thermal expansion coefficient. The inner wall of the outer cylinder 203 is provided with a contact sensor 201, and the thermal expansion protrusion 204 corresponds to the position of the contact sensor 201, and there is a small gap between the top of the thermal expansion protrusion 204 and the contact sensor 201.

[0052] In this way, when the working gas temperature in the cavity connecting pipeline 22 does not exceed the temperature threshold (for example, 800° C.), there is a small gap between the top of the thermal expansion protrusion 204 and the contact sensor 201, and the inner tube 202 and the outer tube 203 are isolated from each other by air. The gap between the inner tube 202 and the outer tube 203 can form air insulation, see Figure 3 .

[0053] When the working gas temperature in the cavity connecting pipe 22 exceeds the temperature threshold (for example, 800° C.), the heat in the working gas is transferred to the thermal expansion protrusion 204, so that the thickness of the thermal expansion protrusion 204 increases, and the outer ring surface of the thermal expansion protrusion 204 contacts the contact sensor 201, see Figure 4 The thermal expansion protrusions 204 and the contact sensor 201 that are in contact with each other form a heat-conducting column as a heat-conducting structure, so that the inner cylinder 202 exchanges heat with the external environment. The heat of the working gas is transferred to the external environment through the inner cylinder 202, the thermal expansion protrusions 204, the contact sensor 201 and the outer cylinder 203 in turn.

[0054] It should be noted that, through the specially structured cavity connecting pipeline 2, it is possible to realize automatic adjustment of the working gas temperature in the inner cylinder 202 without setting a temperature sensor and without destroying the overall structure and air tightness of the inner cylinder 202, thereby avoiding the situation where the working gas temperature is too high at the position where the cavity connecting pipeline 2 is close to the process chamber 1.

[0055] In another embodiment, the process chamber 1 includes a heat-conducting inner chamber 101, a heat-insulating outer shell 102, a heating body 103 and a bracket 104, see Figure 5The heat-insulating outer shell 102 is sleeved on the outer wall of the heat-conducting inner cavity 101, the heating body 103 is arranged between the heat-insulating outer shell 102 and the heat-conducting inner cavity 101 and is in direct contact with the heat-conducting inner cavity 101, the bracket 104 is arranged in the heat-conducting inner cavity 101, and the substrate 17 is placed on the bracket 104. The process chamber 1 with such a structure can realize uniform heating of the substrate 17.

[0056] In order to preheat the working gas, the working gas supply unit 15 is connected to the inner cavity of the process chamber 1 through a preheating pipeline. The structure of the preheating pipeline includes a heat transfer inner tube and an insulating outer tube 21 sleeved on the outer wall of the heat transfer inner tube. The heat transfer inner tube and the heat conductive inner cavity 101 are made of the same material, and one end of the heat transfer inner tube is in direct contact with the heat conductive inner cavity 101. The heat generated by the heating body 103 is transferred to the heat conductive inner cavity 101, and the substrate 17 is radiantly heated by the heat conductive inner cavity 101. The heat is transferred to the heat transfer inner tube along the heat conductive inner cavity 101 to preheat the working gas flowing in the heat transfer inner tube.

[0057] In addition, it should be noted that, in actual applications, since the heat transfer inner tube is at a certain distance from the heating body 103, the working gas flowing in the heat transfer inner tube is usually not heated to 800-1000°C.

[0058] In order to fully preheat the working gas, the above-mentioned heat transfer inner tube includes a first constant diameter section 18, a spherical cavity section 19 and a second constant diameter section 20 which are connected in sequence from the working gas supply unit 15 to the process chamber 1. The gas outlet direction of the first constant diameter section 18 is tangent to the spherical cavity section 19, so that the working gas flowing out of the first constant diameter section 18 is supplied into the spherical cavity section 19 along the tangent direction of the spherical cavity section 19 and swirls in the spherical cavity section 19, thereby extending the residence time of the working gas in the heat transfer inner tube and ensuring sufficient preheating of the working gas.

[0059] In order to further improve the preheating effect of the working gas, the diameter of the spherical cavity section 19 is larger than the diameter of the first constant diameter section 18. The flow rate of the working gas flowing from the first constant diameter section 18 into the spherical cavity section 19 will be appropriately reduced, further extending the residence time of the working gas in the spherical cavity section 19.

[0060] In order to ensure the working gas flow rate supplied into the process chamber 1, the diameter of the spherical cavity section 19 is larger than the diameter of the second constant diameter section 20. In this way, the flow rate of the working gas flowing from the spherical cavity section 19 into the second constant diameter section 20 will be appropriately increased so that more working gas can flow onto the substrate 17.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A centralized exhaust unit, characterized in that: Used for exhausting a process chamber in semiconductor process equipment, the centralized exhaust unit includes an exhaust fan and multiple vacuum pumps, the gas outlet of the process chamber is connected to the exhaust fan through a vacuum pump, the process chamber corresponds to the vacuum pump one by one, and multiple vacuum pumps correspond to one exhaust fan.

2. The centralized exhaust unit according to claim 1, characterized in that: It also includes an exhaust pipeline, and multiple vacuum pumps are connected to the exhaust fan through the exhaust pipeline.

3. The centralized exhaust unit according to claim 1, characterized in that: The exhaust pipeline includes an exhaust main pipe and multiple exhaust branch pipes, one end of the exhaust branch pipe is connected to the air outlet of the vacuum pump, the other end of the exhaust branch pipe is connected to the exhaust main pipe, and the air outlet of the exhaust main pipe is connected to the exhaust fan.

4. The centralized exhaust unit according to claim 3, characterized in that: The exhaust branch pipes correspond to the vacuum pumps one by one.

5. The centralized exhaust unit according to claim 1, characterized in that: It also includes a main pipe pressure sensor and a fan controller, wherein the fan controller is connected to the main pipe pressure sensor and the exhaust fan respectively, and the main pipe pressure sensor is arranged in the exhaust pipe.

6. The centralized exhaust unit according to claim 1, characterized in that: It also includes a cavity pressure sensor, a front flow regulating valve and a front flow controller. The cavity pressure sensor is arranged in the process cavity, the front flow regulating valve is arranged on the connecting pipeline between the process cavity and the vacuum pump, and the front flow controller is connected to the cavity pressure sensor and the front flow regulating valve respectively.

7. The centralized exhaust unit according to claim 1, characterized in that: It also includes a branch pipe pressure sensor, a post-flow regulating valve and a post-flow controller. The branch pipe pressure sensor is arranged in the exhaust branch pipe, the post-flow regulating valve is arranged on the exhaust branch pipe, and the post-flow controller is connected to the branch pipe pressure sensor and the post-flow regulating valve respectively.

8. The centralized exhaust unit according to claim 7, characterized in that: Along the gas flow direction, the branch pipe pressure sensor is located before the post-flow regulating valve.

9. The centralized exhaust unit according to claim 1, characterized in that: The number of the process chambers and vacuum pumps is 4 to 6.

10. A semiconductor process equipment, characterized in that: It comprises a working gas supply unit, a process chamber and a centralized exhaust unit which are connected in sequence, and the centralized exhaust unit is the centralized exhaust unit as claimed in any one of claims 1 to 9.

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