Wafer refrigerating system of ion implanter

Abstract

The invention discloses a wafer refrigerating system of an ion implanter, which is characterized in that a cold ring and a process target disc for bearing a first wafer are arranged in a process chamber, the process target disc is arranged at the top of the cold ring, and the bottom of the cold ring is connected with a distributor through a refrigerant penetrating pipe; a pre-cooling ring and a pre-cooling target disc used for bearing a second wafer are arranged in a mechanical arm cavity, the pre-cooling ring is arranged at the bottom of the pre-cooling target disc, the bottom of the pre-cooling ring is connected with a distributor through a pipeline, the distributor is connected with a cold source through a pipeline, and low-temperature nitrogen provided by the cold source is conveyed into the distributor to be distributed for the second time. Then the wafers are conveyed to a cooling ring and a pre-cooling ring respectively, so that the first wafer on the process target disc and the second wafer on the pre-cooling target disc are cooled to a preset temperature; and the low-temperature nitrogen is subjected to heat exchange in the cold ring and the pre-cooling ring, then returns to the distributor and finally returns to the cold source for cyclic utilization. The low-temperature injection device has the characteristics of compact structure, convenience in operation, high refrigeration efficiency and the like, and the overall working efficiency of low-temperature injection is improved.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor device manufacturing equipment, and in particular to a wafer cooling system of an ion implanter. Background Art

[0002] Semiconductor component manufacturing technology and processes are very complex. In the semiconductor process involved, during the ion implantation process, it is necessary to obtain a thicker amorphous layer, a smoother amorphous / single crystal interface and fewer end-of-range (EOR) defects, achieve higher activation and lower diffusion, and achieve better electrical performance (low leakage current, pipeline defects, etc.) of the terminal product. However, in the prior art, it is impossible to obtain a thicker amorphous layer, a smoother amorphous / single crystal interface and fewer end-of-range (EOR) defects during the ion implantation process at room temperature to -90°C. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a wafer cooling system for an ion implanter with a compact structure, convenient operation and high cooling efficiency in view of the above-mentioned problems in the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A wafer cooling system for an ion implanter comprises: a process target plate, a cold ring, a refrigerant pipe, a distributor, a cold source, a pre-cooling ring and a pre-cooling target plate; the process target plate and the cold ring are arranged in a process chamber, and the process target plate is arranged on the top of the cold ring, the process target plate is used to carry a first wafer, the cold ring is evenly provided with cooling channels inside, and the bottom of the cold ring is connected to the distributor through the refrigerant pipe; the pre-cooling ring and the pre-cooling target plate are arranged in a manipulator chamber, and the pre-cooling ring is arranged at the bottom of the pre-cooling target plate, and the pre-cooling target plate is used to Carrying the second wafer, the pre-cooling ring is evenly distributed with cooling channels inside, the bottom of the pre-cooling ring is connected to the distributor through a pipeline, the distributor is connected to the cold source through a pipeline, the low-temperature nitrogen provided by the cold source is transported to the distributor for secondary distribution, and then transported to the cold ring and the pre-cooling ring respectively, so as to realize the first wafer on the process target disk and the second wafer on the pre-cooling target disk to the preset temperature; after the low-temperature nitrogen exchanges heat in the cold ring and the pre-cooling ring, it returns to the distributor, and finally returns to the cold source for recycling.

[0006] As a further improvement of the present invention, a heater is provided inside the distributor, and the input end of the heater is connected to the factory nitrogen source through a nitrogen input pipe, and the input end of the heater is connected to the process chamber and the robot chamber through a nitrogen output pipe; when the ion implantation process is completed, the factory nitrogen input by the nitrogen input pipe is heated to a preset temperature by the heater, and then transported to the process chamber and the robot chamber by the nitrogen output pipe to achieve heating of the first wafer and the second wafer.

[0007] As a further improvement of the present invention, the wafer cooling system also includes a process target gas supply source, which is connected to the process target plate through a gas pipeline, the upper surface of the process target plate is in physical contact with the lower surface of the first wafer of the first wafer, and the exhaust port of the process target gas supply source is located between the upper surface of the process target plate and the lower surface of the first wafer; during the wafer cooling process, the process target gas supply source opens 5Torr-30Torr nitrogen for gas supply.

[0008] As a further improvement of the present invention, a first temperature sensor is installed on the lower surface of the process target disk to collect temperature data of the process target disk in real time.

[0009] As a further improvement of the present invention, the wafer cooling system also includes a cold ring gas supply source, which is connected to the cold ring through a gas pipeline, the upper surface of the cold ring is in physical contact with the lower surface of the process target disk, and the exhaust port of the cold ring gas supply source is located between the upper surface of the cold ring and the lower surface of the process target disk. During the wafer cooling process, the cold ring gas supply source turns on 5Torr-30Torr nitrogen for gas supply.

[0010] As a further improvement of the present invention, a second temperature sensor is installed on the lower surface of the cold ring of the cold ring to collect temperature data of the cold ring in real time.

[0011] As a further improvement of the present invention, the wafer cooling system also includes a pre-cooling target gas supply source, which is connected to the pre-cooling target plate through a gas pipeline, the upper surface of the pre-cooling target plate is in physical contact with the lower surface of the second wafer of the second wafer, and the exhaust port of the pre-cooling target gas supply source is located between the upper surface of the pre-cooling target plate and the lower surface of the second wafer. During the wafer cooling process, the pre-cooling target gas supply source turns on 5Torr-30Torr nitrogen for gas supply.

[0012] As a further improvement of the present invention, a sixth temperature sensor is installed on the lower surface of the pre-cooling ring of the pre-cooling ring to collect the temperature data of the pre-cooling ring in real time; a seventh temperature sensor is installed on the lower surface of the pre-cooling target plate of the pre-cooling target plate to collect the temperature data of the pre-cooling target plate in real time.

[0013] As a further improvement of the present invention, the distributor is provided with a first output pipe, a first return pipe, a second return pipe and a second output pipe; the first output pipe is connected to the cooling medium input port of the refrigerant pipe, and the first return pipe is connected to the cooling medium return port of the refrigerant pipe to realize the recycling of the cooling medium in the cooling loop; the first output pipe is provided with a second pressure sensor and a fourth temperature sensor; the second output pipe is connected to the cooling medium input port of the pre-cooling ring, and the second return pipe is connected to the cooling medium return port of the pre-cooling ring to realize the recycling of the cooling medium in the pre-cooling ring; the second output pipe is provided with a first pressure sensor and a third temperature sensor.

[0014] As a further improvement of the present invention, a cold source working fluid output pipe and a cold source working fluid return pipe are provided on the cold source, the cold source working fluid output pipe is connected to the cooling working fluid input port of the distributor, and the cold source working fluid return pipe is connected to the cooling working fluid return port of the distributor to realize the circulation of the cooling working fluid in the distributor; the cold source working fluid output pipe is provided with a third pressure sensor and a fifth temperature sensor.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] The wafer refrigeration system of the ion implanter of the present invention arranges a cold ring and a process target plate for carrying a first wafer in a process chamber, and the bottom of the cold ring is connected to a distributor through a refrigerant pipe; a pre-cooling ring and a pre-cooling target plate for carrying a second wafer are arranged in a manipulator chamber, and the bottom of the pre-cooling ring is connected to the distributor through a pipeline, and the distributor is connected to a cold source through a pipeline, thus forming the main structure of the wafer refrigeration system; when the wafer needs to be cooled, the low-temperature nitrogen provided by the cold source is transported to the distributor for secondary distribution, and then transported to the cold ring and the pre-cooling ring according to the actual cooling demand. In order to achieve the cooling of the process target plate and the pre-cooling target plate, the first wafer and the second wafer finally reach the low temperature required by the ion implantation process. The cooling operation process is simple and reliable, and the lowest cooling temperature of nitrogen in the cold source is about -180°C, and the wafer can be cooled to -120°C at the lowest. During the ion implantation process, the implanted part of the wafer can produce a thicker amorphous layer, a smoother amorphous / single crystal interface, and fewer end-of-range (EOR) defects, achieving higher activation and lower diffusion, and achieving better electrical performance (low leakage current, pipeline defects, etc.) of the terminal product. Furthermore, after the low-temperature nitrogen is heat-exchanged in the cold ring and the pre-cooling ring, it returns to the distributor and finally returns to the cold source for recycling, which improves the utilization rate of the refrigerant. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structural principle of a wafer cooling system in a specific embodiment of the present invention;

[0018] Figure 2 for Figure 1 Schematic diagram of the structural principle at A in the middle;

[0019] Legend: 1. First wafer; 101. Lower surface of first wafer; 2. Process target; 201. Upper surface of process target; 202. Lower surface of process target; 203. First temperature sensor; 3. Cold ring; 301. Upper surface of cold ring; 302. Second temperature sensor; 303. Lower surface of cold ring; 4. Refrigerant pipe; 5. Distributor; 501. First output pipe; 502. First return pipe; 503. Second return pipe; 504. Second output pipe; 505. First pressure sensor; 506. Third temperature sensor; 507. Nitrogen input pipe; 508. Second pressure sensor; 509. Fourth temperature sensor; 510. Nitrogen Gas output pipe; 6. process target gas supply source; 7. cold ring gas supply source; 8. cold source; 801. third pressure sensor; 802. fifth temperature sensor; 803. cold source working fluid output pipe; 804. cold source working fluid reflux pipe; 9. pre-cooling target gas supply source; 10. pre-cooling ring; 1001. upper surface of pre-cooling ring; 1002. sixth temperature sensor; 1003. lower surface of pre-cooling ring; 11. pre-cooling target disk; 1101. upper surface of pre-cooling target disk; 1102. seventh temperature sensor; 1103. lower surface of pre-cooling target disk; 12. process chamber; 13. heater; 14. second wafer; 1401. lower surface of second wafer; 15. robot chamber. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] 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.

[0023] Example

[0024] like Figure 1 and Figure 2 As shown, the wafer cooling system of the ion implanter of the present invention includes: a process target plate 2, a cold ring 3, a refrigerant pipe 4, a distributor 5, a cold source 8, a pre-cooling ring 10 and a pre-cooling target plate 11. The process target plate 2 and the cold ring 3 are arranged in a process chamber 12, and the process target plate 2 is arranged on the top of the cold ring 3. The process target plate 2 is used to carry the first wafer 1. Cooling channels are evenly distributed inside the cold ring 3, and the bottom of the cold ring 3 is connected to the distributor 5 through the refrigerant pipe 4. Among them, the refrigerant pipe 4 adopts the conventional setting in the field, and its specific structure is not repeated here. The pre-cooling ring 10 and the pre-cooling target plate 11 are arranged in a robot chamber 15, and the pre-cooling ring 10 is arranged at the bottom of the pre-cooling target plate 11. The pre-cooling target plate 11 is used to carry the second wafer 14. Cooling channels are evenly distributed inside the pre-cooling ring 10. The bottom of the pre-cooling ring 10 is connected to the distributor 5 through a pipeline, and the distributor 5 is connected to the cold source 8 through a pipeline. As shown Figure 1 As shown in the figure, the process chamber 12 is on the left and the robot chamber 15 is on the right. The two chambers are interconnected and both are high vacuum environments with a vacuum degree of ≤5E-7Torr. The low-temperature nitrogen provided by the cold source 8 is transported to the distributor 5 for secondary distribution, and then transported to the cold ring 3 and the pre-cooling ring 10 respectively to achieve the first wafer 1 on the process target plate 2 and the second wafer 14 on the pre-cooling target plate 11 to a preset temperature; the low-temperature nitrogen is heat exchanged in the cold ring 3 and the pre-cooling ring 10, and then returned to the distributor 5, and finally returned to the cold source 8 for recycling.

[0025] In this embodiment, the cold source 8 cools the nitrogen through the internal refrigeration system, and the lowest temperature can be -180°C. When the temperature matches the target temperature, for example, -150°C, the low-temperature nitrogen is circulated in the pipeline under a certain pressure by the compressor inside the cold source 8, circulated to the distributor 5, and then redistributed by the distributor 5 to each refrigeration terminal. There are two refrigeration terminals in the present invention, which are respectively in the high-vacuum process chamber 12 and the robot chamber 15. The process chamber 12 contains the process target plate 2, and the robot chamber 15 contains the pre-cooling target plate 11. The process target plate 2 and the pre-cooling target plate 11 cool the wafer and make the wafer reach the low temperature required for the ion implantation process. The wafer can be cooled to -120°C at the lowest.

[0026] In this embodiment, a cold ring 3 and a process target plate 2 for carrying a first wafer 1 are arranged in a process chamber 12, and the bottom of the cold ring 3 is connected to a distributor 5 through a refrigerant pipe 4; a pre-cooling ring 10 and a pre-cooling target plate 11 for carrying a second wafer 14 are arranged in a robot chamber 15, and the bottom of the pre-cooling ring 10 is connected to the distributor 5 through a pipeline, and the distributor 5 is connected to a cold source 8 through a pipeline, thus constituting the main structure of the wafer refrigeration system. When the wafer needs to be cooled, the low-temperature nitrogen provided by the cold source 8 is transported to the distributor 5 for secondary distribution, and then transported to the cold ring 3 and the pre-cooling ring 10 according to the actual cooling demand, so as to realize the cooling of the process target plate 2 and the pre-cooling target plate 11, and finally realize the first wafer 1 and the second wafer 14 to reach the low temperature required by the ion implantation process. The cooling operation process is simple and reliable, and the lowest cooling temperature of nitrogen in the cold source 8 is about -180°C, and the wafer can be cooled to -120°C at the lowest. During the ion implantation process, the implanted part of the wafer can produce a thicker amorphous layer, a smoother amorphous / single crystal interface, and fewer end-of-range (EOR) defects, so as to achieve higher activation and lower diffusion, and achieve the effect of better electrical performance (low leakage current, pipeline defects, etc.) of the terminal product. Further, after the low-temperature nitrogen is heat-exchanged in the cold ring 3 and the pre-cooling ring 10, it returns to the distributor 5, and finally returns to the cold source 8 for recycling, thereby improving the utilization rate of the refrigerant.

[0027] like Figure 2 As shown, a heater 13 is provided inside the distributor 5. The input end of the heater 13 is connected to the factory nitrogen source through the nitrogen input pipe 507, and the input end of the heater 13 is connected to the process chamber 12 and the robot chamber 15 through the nitrogen output pipe 510. When the ion implantation process is completed, the factory nitrogen input by the nitrogen input pipe 507 is heated to a preset temperature by the heater 13, and then after secondary distribution by the valve group inside the distributor 5, it is transported to the process chamber 12 and the robot chamber 15 by the nitrogen output pipe 510 to achieve the temperature increase of the first wafer 1 and the second wafer 14, which is also beneficial to improve the heat exchange efficiency.

[0028] like Figure 1 As shown, the wafer cooling system also includes a process target gas supply source 6. The process target gas supply source 6 is connected to the process target plate 2 through a gas pipeline, the process target plate upper surface 201 of the process target plate 2 is in physical contact with the first wafer lower surface 101 of the first wafer 1, and the exhaust port of the process target gas supply source 6 is located between the process target plate upper surface 201 and the first wafer lower surface 101. During the wafer cooling process, the process target gas supply source 6 starts 5Torr-30Torr nitrogen gas for gas supply, and the nitrogen gas is evenly distributed between the first wafer 1 and the process target plate 2 to increase the heat exchange efficiency between the process target plate 2 and the first wafer 1, increase the cooling rate of the first wafer 1, and improve the overall work efficiency of low-temperature injection.

[0029] In this embodiment, a first temperature sensor 203 is installed on the lower surface 202 of the process target disk 2 to collect temperature data of the process target disk 2 in real time.

[0030] like Figure 1 As shown, the wafer refrigeration system also includes a cold ring gas supply source 7, which is connected to the cold ring 3 through a gas pipeline, and the cold ring upper surface 301 of the cold ring 3 is in physical contact with the process target disk lower surface 202 of the process target disk 2, and the exhaust port of the cold ring gas supply source 7 is located between the cold ring upper surface 301 and the process target disk lower surface 202. During the wafer refrigeration process, the cold ring gas supply source 7 starts 5Torr-30Torr nitrogen to supply gas to increase the cooling rate of the process target disk 2 in a high vacuum environment.

[0031] In this embodiment, after passing through the refrigerant pipe 4, the low-temperature nitrogen enters the interior of the cold ring 3, which contains a heat exchange pipeline. The low-temperature nitrogen circulates in the internal heat exchange pipeline and is fully heat exchanged to achieve the purpose of cooling the cold ring 3. Furthermore, a second temperature sensor 302 is installed on the lower surface 303 of the cold ring 3 to collect temperature data of the cold ring 3 in real time.

[0032] like Figure 1 As shown, the wafer refrigeration system also includes a pre-cooling target gas supply source 9. The pre-cooling target gas supply source 9 is connected to the pre-cooling target plate 11 through a gas pipeline, and the pre-cooling target plate upper surface 1101 of the pre-cooling target plate 11 is in physical contact with the second wafer lower surface 1401 of the second wafer 14, and the exhaust port of the pre-cooling target gas supply source 9 is located between the pre-cooling target plate upper surface 1101 and the second wafer lower surface 1401. During the wafer refrigeration process, the pre-cooling target gas supply source 9 turns on 5Torr-30Torr nitrogen for gas supply, and the nitrogen is evenly distributed between the second wafer 14 and the pre-cooling target plate 11 to increase the heat exchange efficiency between the pre-cooling target plate 11 and the second wafer 14, increase the cooling rate of the second wafer 14, and improve the overall work efficiency of low-temperature injection.

[0033] In this embodiment, the upper surface 1001 of the precooling ring 10 is in physical contact with the lower surface 1103 of the precooling target disk 11. After passing through 5, the low-temperature nitrogen enters the interior of the precooling ring 10. The interior of the precooling ring 10 contains a heat exchange pipeline. The low-temperature nitrogen circulates in the internal heat exchange pipeline and is fully heat exchanged to achieve the purpose of cooling the precooling ring 10. Further, a sixth temperature sensor 1002 is installed on the lower surface 1003 of the precooling ring 10 to collect temperature data of the precooling ring 10 in real time. A seventh temperature sensor 1102 is installed on the lower surface 1103 of the precooling target disk 11 to collect temperature data of the precooling target disk 11 in real time.

[0034] like Figure 2As shown, the distributor 5 is provided with a first output pipe 501, a first return pipe 502, a second return pipe 503 and a second output pipe 504. The first output pipe 501 is connected to the cooling medium input port of the refrigerant pipe 4, and the first return pipe 502 is connected to the cooling medium return port of the refrigerant pipe 4, so as to realize the recycling of the cooling medium in the cold loop 3. The first output pipe 501 is provided with a second pressure sensor 508 and a fourth temperature sensor 509. The second pressure sensor 508 displays the internal pressure of the pipeline between the distributor 5 and the cold loop 3, and the fourth temperature sensor 509 provides the system with the temperature of the working medium in the pipeline between the distributor 5 and the cold loop 3. The second pressure sensor 508 and the fourth temperature sensor 509 provide real-time feedback to the remote control system to ensure the safe operation of the low-temperature refrigeration system while ensuring the maximum cooling rate. The second output pipe 504 is connected to the cooling medium input port of the precooling ring 10, and the second return pipe 503 is connected to the cooling medium return port of the precooling ring 10, so as to realize the recycling of the cooling medium in the precooling ring 10. The second output pipe 504 is provided with a first pressure sensor 505 and a third temperature sensor 506. The first pressure sensor 505 displays the internal pressure of the pipeline between the distributor 5 and the precooling ring 10, and the third temperature sensor 506 provides the system with the temperature of the working medium in the pipeline between the distributor 5 and the precooling ring 10. The first pressure sensor 505 and the third temperature sensor 506 provide real-time feedback to the remote control system to ensure the safe operation of the low-temperature refrigeration system while ensuring the maximum cooling rate.

[0035] In this embodiment, a low-temperature flow regulating valve is provided inside the distributor 5. Based on the monitoring data of the first temperature sensor 203, the second temperature sensor 302, the sixth temperature sensor 1002 and the seventh temperature sensor 1102, combined with the process required temperature and cooling rate of low-temperature injection, the low-temperature flow regulating valve inside the distributor 5 automatically adjusts the opening to match the rapid balance between the required temperature and the actual temperature.

[0036] In this embodiment, when the distributor 5 performs secondary distribution, there are two routes. The first route is the refrigeration circuit of the process target plate 2. The low-temperature nitrogen passes through the first output pipe 501 and the inlet pipe of the refrigerant pipe 4 to reach the cold ring 3 for heat exchange, cools the cold ring 3, and the cold ring 3 contacts and cools the process target plate 2. At the same time, the cold ring gas supply source 7 is turned on to continuously pass a certain amount of nitrogen between the cold ring 3 and the process target plate 2 until the process target plate 2 reaches the target temperature. The process target plate 2 cools the first wafer 1 to the process required temperature, and at the same time, the process target gas supply source 6 is turned on to continuously pass a certain amount of nitrogen between the process target plate 2 and the first wafer 1 until the temperature of the first wafer 1 reaches the target temperature. At this time, the low-temperature nitrogen will have a temperature rise after heat exchange through the cold ring 3. The nitrogen after temperature rise returns to the distributor 5 through the pipeline outlet of the cold ring 3, the outlet pipe of the refrigerant pipe 4, and the first reflux pipe 502, and then returns to the cold source 8, and is recycled through the internal circulation system of the cold source 8 for refrigeration.

[0037] The second route is the refrigeration circuit for the precooling target disk 11. The low-temperature nitrogen reaches the precooling ring 10 through the second output pipe 504, and cools the precooling ring 10 through heat exchange in the internal pipeline of the precooling ring 10. The precooling ring 10 exchanges heat and cools the precooling target disk 11 through physical contact. The second wafer 14 is on the precooling target disk 11, and the two are in physical contact. At the same time, the precooling target gas supply source 9 is turned on, and a certain amount of nitrogen is continuously introduced between the second wafer 14 and the precooling target disk 11 until the precooling target disk 11 and the second wafer 14 are cooled to the process required temperature. The low-temperature nitrogen after heat exchange in the precooling ring 10 is warmed up. The warmed nitrogen returns to the distributor 5 through the pipeline outlet of the precooling ring 10 and the second reflux pipe 503, and then returns to the cold source 8, and is recycled for refrigeration through the internal circulation system of the cold source 8.

[0038] like Figure 1 and Figure 2 As shown, a cold source medium output pipe 803 and a cold source medium return pipe 804 are provided on the cold source 8, the cold source medium output pipe 803 is connected to the cooling medium input port of the distributor 5, and the cold source medium return pipe 804 is connected to the cooling medium return port of the distributor 5, so as to realize the circulation of the cooling medium in the distributor 5. A third pressure sensor 801 and a fifth temperature sensor 802 are provided on the cold source medium output pipe 803. The third pressure sensor 801 displays the internal pressure of the pipeline between the cold source 8 and the distributor 5, and the fifth temperature sensor 802 provides the system with the temperature of the medium in the pipeline between the cold source 8 and the distributor 5. The third pressure sensor 801 and the fifth temperature sensor 802 provide real-time feedback to the system, so as to ensure the safe operation of the low-temperature refrigeration system while ensuring the maximum cooling rate.

[0039] In this embodiment, a low-temperature regulating device is provided inside the cold source 8. According to the monitoring data of the first temperature sensor 203, the second temperature sensor 302, the sixth temperature sensor 1002 and the seventh temperature sensor 1102, combined with the process required temperature and cooling rate of low-temperature injection, the low-temperature regulating device inside the cold source 8 automatically adjusts the power and internal flow of the cold source, adjusts the pipeline pressure and the working fluid temperature, so as to match the rapid balance between the required temperature and the actual temperature.

[0040] The working principle of the wafer cooling system of this embodiment is:

[0041] The refrigeration system inside the cold source 8 cools the nitrogen, and the lowest refrigeration temperature is about -180°C. The compressor inside the cold source 8 applies a certain pressure to the low-temperature nitrogen, so that the low-temperature nitrogen circulates in the refrigerant pipeline. First, the low-temperature nitrogen is transported to the distributor 5 through the cold source working medium output pipe 803. The distributor 5 performs secondary distribution of the low-temperature nitrogen by opening and closing the internal low-temperature valve and is divided into two refrigeration circuits. The first circuit is the refrigeration circuit of the process target plate 2. The low-temperature nitrogen passes through the first output pipe 501 and the inlet pipe of the refrigerant pipe 4, and reaches the cold ring 3 for heat exchange, cooling the cold ring 3, and the cold ring 3 contacts and cools the process target plate 2. The process target plate 2 cools the first wafer 1 to the process required temperature. At this time, the low-temperature nitrogen will have a temperature rise after heat exchange. The nitrogen after temperature rise returns to the distributor 5 through the pipeline outlet of the cold ring 3, the outlet of the refrigerant pipe 4, and the first return pipe 502, and then returns to the cold source 8 through the cold source working medium return pipe 804, and is recycled through the internal circulation system of the cold source 8 for refrigeration. At the same time, the second route is the refrigeration circuit of the pre-cooling target plate 11. The low-temperature nitrogen reaches the pre-cooling ring 10 through the second output pipe 504, and the pre-cooling ring 10 is cooled by the heat exchange of the internal pipeline of the pre-cooling ring 10. The pre-cooling ring 10 performs heat exchange and cooling on the pre-cooling target plate 11 through physical contact, and the temperature is cooled to the process required temperature. The low-temperature nitrogen after heat exchange has a temperature recovery, and the nitrogen after temperature rise returns to the distributor 5 through the pipeline outlet of the pre-cooling ring 10 and the second return pipe 503, and then returns to the cold source 8 through the cold source working medium return pipe 804, and is recycled through the internal circulation system of the cold source 8 for refrigeration.

[0042] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A wafer cooling system for an ion implanter, characterized in that: include: A process target plate (2), a cooling ring (3), a cooling medium pipe (4), a distributor (5), a cooling source (8), a pre-cooling ring (10) and a pre-cooling target plate (11); the process target plate (2) and the cooling ring (3) are arranged in a process chamber (12), and the process target plate (2) is arranged on the top of the cooling ring (3); the process target plate (2) is used to carry a first wafer (1); cooling channels are evenly distributed inside the cooling ring (3); the bottom of the cooling ring (3) is connected to the distributor (5) through the cooling medium pipe (4); the pre-cooling ring (10) and the pre-cooling target plate (11) are arranged in a robot chamber (15), and the pre-cooling ring (10) is arranged at the bottom of the pre-cooling target plate (11); the pre-cooling target plate (11) is used to cool the target plate (11) and the cooling medium pipe (4) is connected to the distributor (5); the pre-cooling ring (10) and the pre-cooling target plate (11) are arranged in a robot chamber (15), and the pre-cooling ring (10) is arranged at the bottom of the pre-cooling target plate (11); The precooling ring (10) is provided with cooling channels evenly distributed inside for carrying the second wafer (14). The bottom of the precooling ring (10) is connected to the distributor (5) through a pipeline. The distributor (5) is connected to the cold source (8) through a pipeline. The low-temperature nitrogen provided by the cold source (8) is transported to the distributor (5) for secondary distribution and then transported to the cold ring (3) and the precooling ring (10) respectively, so as to cool the first wafer (1) on the process target plate (2) and the second wafer (14) on the precooling target plate (11) to a preset temperature. After the low-temperature nitrogen is heat-exchanged in the cold ring (3) and the precooling ring (10), it is returned to the distributor (5) and finally returned to the cold source (8) for recycling.

2. The wafer cooling system of the ion implanter according to claim 1, characterized in that: A heater (13) is provided inside the distributor (5); the input end of the heater (13) is connected to a factory nitrogen source via a nitrogen input pipe (507); the input end of the heater (13) is connected to a process chamber (12) and a robot chamber (15) via a nitrogen output pipe (510); after the ion implantation process is completed, the factory nitrogen inputted through the nitrogen input pipe (507) is heated to a preset temperature by the heater (13), and then transported to the process chamber (12) and the robot chamber (15) via the nitrogen output pipe (510), so as to increase the temperature of the first wafer (1) and the second wafer (14).

3. The wafer cooling system of the ion implanter according to claim 2, characterized in that: The wafer cooling system further comprises a process target gas supply source (6), wherein the process target gas supply source (6) is connected to the process target plate (2) via a gas pipeline, the process target plate upper surface (201) of the process target plate (2) is in physical contact with the first wafer lower surface (101) of the first wafer (1), and the exhaust port of the process target gas supply source (6) is located between the process target plate upper surface (201) and the first wafer lower surface (101); during the wafer cooling process, the process target gas supply source (6) starts to supply nitrogen gas of 5 Torr-30 Torr.

4. The wafer cooling system of the ion implanter according to claim 3, characterized in that: A first temperature sensor (203) is installed on the lower surface (202) of the process target disk (2) to collect temperature data of the process target disk (2) in real time.

5. The wafer cooling system of the ion implanter according to claim 3, characterized in that: The wafer cooling system also includes a cold ring gas supply source (7), the cold ring gas supply source (7) is connected to the cold ring (3) through a gas pipeline, the cold ring upper surface (301) of the cold ring (3) is in physical contact with the process target disk lower surface (202) of the process target disk (2), the exhaust port of the cold ring gas supply source (7) is located between the cold ring upper surface (301) and the process target disk lower surface (202), and during the wafer cooling process, the cold ring gas supply source (7) starts 5Torr-30Torr nitrogen for gas supply.

6. The wafer cooling system of the ion implanter according to claim 5, characterized in that: A second temperature sensor (302) is installed on the lower surface (303) of the cold ring (3) to collect temperature data of the cold ring (3) in real time.

7. The wafer cooling system of the ion implanter according to claim 5, characterized in that: The wafer refrigeration system further comprises a precooling target gas supply source (9), wherein the precooling target gas supply source (9) is connected to the precooling target plate (11) through a gas pipeline, the precooling target plate upper surface (1101) of the precooling target plate (11) is in physical contact with the second wafer lower surface (1401) of the second wafer (14), the exhaust port of the precooling target gas supply source (9) is located between the precooling target plate upper surface (1101) and the second wafer lower surface (1401), and during the wafer refrigeration process, the precooling target gas supply source (9) starts nitrogen gas of 5 Torr-30 Torr for gas supply.

8. The wafer cooling system of the ion implanter according to claim 7, characterized in that: A sixth temperature sensor (1002) is installed on the lower surface (1003) of the precooling ring (10) to collect temperature data of the precooling ring (10) in real time; and a seventh temperature sensor (1102) is installed on the lower surface (1103) of the precooling target disk (11) to collect temperature data of the precooling target disk (11) in real time.

9. The wafer cooling system for an ion implanter according to any one of claims 1 to 8, characterized in that: The distributor (5) is provided with a first output pipe (501), a first return pipe (502), a second return pipe (503) and a second output pipe (504); the first output pipe (501) is connected to the cooling medium input port of the refrigerant pipe (4), and the first return pipe (502) is connected to the cooling medium return port of the refrigerant pipe (4) to realize the recycling of the cooling medium in the cooling ring (3); the first output pipe (501) is provided with a second pressure sensor (508) and a fourth temperature sensor (509); the second output pipe (504) is connected to the cooling medium input port of the pre-cooling ring (10), and the second return pipe (503) is connected to the cooling medium return port of the pre-cooling ring (10) to realize the recycling of the cooling medium in the pre-cooling ring (10); the second output pipe (504) is provided with a first pressure sensor (505) and a third temperature sensor (506).

10. The wafer cooling system for an ion implanter according to any one of claims 1 to 8, characterized in that: The cold source (8) is provided with a cold source working medium output pipe (803) and a cold source working medium return pipe (804); the cold source working medium output pipe (803) is connected to the cooling working medium input port of the distributor (5); the cold source working medium return pipe (804) is connected to the cooling working medium return port of the distributor (5), so as to realize the circulation of the cooling working medium in the distributor (5); and the cold source working medium output pipe (803) is provided with a third pressure sensor (801) and a fifth temperature sensor (802).

Images