Multifunctional heating plate used in ultrahigh vacuum environment

Abstract

The invention belongs to the technical field of vacuum application equipment, and particularly relates to a multifunctional heating plate used in an ultrahigh vacuum environment, which comprises an upper heating plate assembly, a lower tray assembly, a lower tray transmission mechanism and auxiliary functional accessories, the lower tray assembly is located on the lower portion in the vacuum cavity and can move up and down, the lower tray assembly is driven by the lifting power source and the lower tray transmission mechanism to move up and down, and online sample bearing can be achieved. In the annealing process, a radio frequency power supply can be connected through a substrate support on the lower tray assembly, and backwash cleaning can be conducted on a substrate under the condition that argon is introduced. The device is simple in structure, stable and reliable in action, controllable and adjustable in temperature, capable of being used in high and ultrahigh vacuum environments and wide in application range.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vacuum application equipment, in particular to a multifunctional heating disc used in an ultrahigh vacuum environment. BACKGROUND

[0002] When scientific research and industrial production are carried out in a vacuum environment, an ultrahigh vacuum annealing system is needed to anneal wafers (substrates) by using a high-temperature heating disc under the premise of reaching a high vacuum degree. Some substrates need to be cleaned before being plated. At present, mainstream film plating equipment produced at home and abroad has a substrate size that increases year by year. It has become a top priority to develop qualified 12-inch wafers that meet certain use conditions. As an important process on such equipment, a high-temperature heating disc for pre-plating cleaning and post-plating annealing is born in response to the situation. This equipment can be connected to a complex multi-process linkage system to realize online automatic substrate receiving. SUMMARY

[0003] In order to meet the annealing requirements of 12-inch wafers, the purpose of the present application is to provide a multifunctional heating disc used in an ultrahigh vacuum environment.

[0004] The purpose of the present application is achieved by the following technical solutions:

[0005] The present application comprises an upper heating disc assembly, a lower tray assembly, a lower tray transmission mechanism, and a substrate holder. The upper heating disc assembly and the lower tray assembly are both located in a vacuum chamber. The upper heating disc assembly is fixed in the vacuum chamber. The lower tray transmission mechanism is fixed outside the vacuum chamber. The substrate holder is fixed to the upper end of the lower tray assembly and is used to place wafers. The lower end of the lower tray assembly is connected to a lifting power source through the lower tray transmission mechanism. The lifting power source drives the lower tray assembly, the substrate holder, and the wafers placed on the substrate holder to lift and lower, realizing the opening and closing of the upper heating disc assembly. The upper heating disc assembly comprises an upper shielding cover and a main heating disc. The main heating disc is fixed to the bottom surface of the upper shielding cover. When the upper heating disc assembly and the lower tray assembly are closed, the main heating disc anneals the wafers placed on the substrate holder.

[0006] The upper surface of the upper shielding cover is fixed with an upper water cooling disc. The upper surface of the upper water cooling disc is spirally laid with an upper water cooling disc pipe.

[0007] The two ends of the upper water cooling disc pipe are respectively connected with a water cooling disc water inlet connector and a water cooling disc water outlet connector. The water cooling disc water inlet connector and the water cooling disc water outlet connector are respectively sealed and fixed on the vacuum chamber through a mounting flange A and are located outside the vacuum chamber.

[0008] The upper shielding cover is uniformly provided with a plurality of water-cooling support rods along the circumferential direction, the bottom end of each water-cooling support rod is fixedly connected with the upper shielding cover, the upper end of each water-cooling support rod is extended out of the vacuum chamber, each water-cooling support rod is fixedly connected with the vacuum chamber through the mounting flange A, and the upper end of each water-cooling support rod is connected with a water-cooling rod water inlet joint and a water-cooling rod water outlet joint.

[0009] The upper shielding cover is uniformly provided with a plurality of water-cooling support rods along the circumferential direction, the bottom end of each water-cooling support rod is fixedly connected with the upper shielding cover, the upper end of each water-cooling support rod is extended out of the vacuum chamber, each water-cooling support rod is fixedly connected with the vacuum chamber through the mounting flange A, and the upper end of each water-cooling support rod is connected with a water-cooling rod water inlet joint and a water-cooling rod water outlet joint.

[0010] The lower tray assembly comprises a lower shielding cover and a lower tray support, the lower shielding cover is fixed at the upper end of the lower tray support, the lower end of the lower tray support is extended out of the vacuum chamber and connected with the lower tray transmission mechanism.

[0011] The lower end of the lower tray support is provided with a quartz insulation plate fixed on the lower shielding cover.

[0012] 8. The lower tray transmission mechanism comprises a belt transmission assembly, a lead screw, a nut, a mounting flange B, a mounting frame and a connecting plate, the mounting frame is fixedly connected with the vacuum chamber through the mounting flange B, the lifting power source is fixed on the mounting frame, the lead screw is rotatably installed on the mounting frame, the output end of the lifting power source is connected with the lead screw through the belt transmission assembly to drive the rotation of the lead screw, the nut is threadedly connected with the lead screw, one end of the connecting plate is fixedly connected with the nut, and the other end of the connecting plate is connected with the lower end of the lower tray support; a bellows is sleeved on the lower end of the lower tray support between the mounting flange B and the connecting plate, the upper end of the bellows is fixed on the mounting flange B, and the lower end of the bellows is fixed on the connecting plate.

[0013] A guide column is fixedly connected with the mounting frame, the guide column is arranged in parallel with the lead screw, and a guide sleeve is sleeved on one end of the connecting plate.

[0014] An air inlet is arranged on the vacuum chamber, the air inlet is in communication with the first interface of the three-way joint, the second interface of the three-way joint is in communication with an oxygen source through a pipeline and is provided with an electromagnetic valve on the pipeline, and the third interface of the three-way joint is in communication with an argon source through a pipeline and is provided with an electromagnetic valve on the pipeline.

[0015] The advantages and positive effects of the present application are as follows:

[0016] 1. The present application has compact structure, convenient assembly, is suitable for ultra-high vacuum environment, has good heating uniformity, stable and reliable action, high cooperation degree with other systems, can clean and anneal 12-inch and below wafer in ultra-high vacuum environment, can be used in high and ultra-high vacuum environment, has wide application range and high practicality.

[0017] 2. In the working process of the present application, the upper and lower closed heating forms have good heat preservation effect, uniform heating temperature and small power consumption.

[0018] 3. The present application uses welded corrugated pipe to isolate atmosphere, uses external servo motor to drive the lifting of the lower tray assembly, the selected parts have small air release amount, can be used in ultra-high vacuum condition, and has wide application range.

[0019] 4. In the working process of the present application, the lower tray assembly can move up and down, so that the wafer can be taken and placed well. DETAILED DESCRIPTION

[0020] Figure 1 is a schematic diagram of the three-dimensional structure of the present application;

[0021] Figure 2 is a main view of the structure of the present application;

[0022] Figure 3 is a schematic diagram of the upper heating disc assembly of the present application;

[0023] Figure 4 is a schematic diagram of the upper heating disc assembly of the present application;

[0024] Figure 5 is a schematic diagram of the lower tray assembly of the present application;

[0025] Figure 6 is a schematic diagram of the lower tray assembly of the present application;

[0026] Figure 7 is a sectional view of the structure of the present application installed on the vacuum chamber;

[0027] Figure 8 is a schematic diagram of the overall structure of the present application installed on the vacuum chamber;

[0028] Wherein: 1 is a temperature measuring and controlling thermocouple, 2 is an upper heating disc assembly, 201 is an upper shielding cover, 202 is an upper water cooling disc, 203 is a main heating disc, 204 is a water cooling support rod, 205 is a water cooling disc water inlet connector, 206 is a water cooling disc water outlet connector, 207 is a water cooling rod water inlet connector, 208 is a water cooling rod water outlet connector, 209 is an upper water cooling disc pipe, 210 is a mounting flange A, 3 is a lower tray assembly, 301 is a lower shielding cover, 302 is a lower tray support, 4 is a lower tray transmission mechanism, 401 is a servo motor, 402 is a pulley A, 403 is a belt, 404 is a pulley B, 405 is a lead screw, 406 is a lead screw nut, 407 is a guide sleeve, 408 is a guide column, 409 is a mounting flange B, 410 is a corrugated pipe, 411 is a mounting bracket, 412 is a connecting plate, 5 is a wafer, 6 is a wafer holder, 7 is a quartz insulation plate, 8 is an air inlet, and 9 is a vacuum chamber. DETAILED DESCRIPTION

[0029] The application will be further described below in conjunction with the drawings.

[0030] As shown in Figure 1 , Figure 2 and Figure 7 , Figure 8 , the application comprises an upper heating disc assembly 2, a lower tray assembly 3, a lower tray transmission mechanism 4 and a wafer holder 6, wherein the upper heating disc assembly 2 and the lower tray assembly 3 are both located in the vacuum chamber 9, the upper heating disc assembly 2 is fixed in the vacuum chamber 9, the lower tray transmission mechanism 4 is fixed outside the vacuum chamber 9 and located below the upper heating disc assembly 2, and the lower tray assembly 3 is located between the upper heating disc assembly 2 and the lower tray transmission mechanism 4; the wafer holder 6 is fixed at the upper end of the lower tray assembly 3 and used for placing the wafer 5, and the lower end of the lower tray assembly 3 is connected with a lifting power source through the lower tray transmission mechanism 4; the lifting power source drives the lower tray assembly 3, the wafer holder 6 and the wafer 5 placed on the wafer holder 6 to lift through the lower tray transmission mechanism 4, so as to realize the opening and closing of the upper heating disc assembly 2, the sample and wafer exchange, and the wafer taking and placing between the upper heating disc assembly 2 and other systems in an ultrahigh vacuum environment.

[0031] The wafer 5 in the embodiment is a 12-inch wafer, and the wafer holder 6 is divided into two parts of the same shape and size and symmetrically arranged, and the inner surfaces of each part are located on the circumference of a circle with a diameter of 12 inches, so that the 12-inch wafer is automatically centered after being placed on the wafer holder 6.

[0032] As shown in Figures 1 to 4 and Figure 7 , Figure 8As shown, the upper heating disc assembly 2 of the present embodiment comprises an upper shielding cover 201 and a main heating disc 203 fixed on the bottom surface of the upper shielding cover 201. When the upper heating disc assembly 2 and the lower tray assembly 3 are closed, the main heating disc 203 performs annealing treatment on the wafer 5 placed on the substrate support 6. The main heating disc 203 of the present embodiment is a commercially available product, which is a high-nickel alloy armored heating disc purchased from Shanghai Hongdu Electric Appliance Co., Ltd. and is of a double-input form, satisfying the use conditions under the ultra-high vacuum environment and high temperature.

[0033] The upper water cooling disc 202 is fixed above the top surface of the upper shielding cover 201. The upper surface of the upper water cooling disc 202 is spirally laid with upper water cooling disc pipes 209. The two ends of the upper water cooling disc pipes 209 are respectively connected with a water cooling disc water inlet connector 205 and a water cooling disc water outlet connector 206. The water cooling disc water inlet connector 205 and the water cooling disc water outlet connector 206 are respectively sealingly and fixedly connected with the vacuum chamber 9 through a mounting flange A 210 and are located outside the vacuum chamber 9.

[0034] The present embodiment is uniformly provided with a plurality of water cooling support rods 204 along the circumferential direction of the outer edge of the upper shielding cover 201. The bottom end of each water cooling support rod 204 is fixed with the upper shielding cover 201 and the upper water cooling disc 202. The upper end of each water cooling support rod 204 extends out of the vacuum chamber 9. Each water cooling support rod 204 is sealingly and fixedly connected with the vacuum chamber 9 through the mounting flange A 210. Each water cooling support rod 204 is provided with a cooling water channel. The upper end of each water cooling support rod 204 is respectively connected with a water cooling rod water inlet connector 207 and a water cooling rod water outlet connector 208. The water cooling rod water inlet connector 207 and the water cooling rod water outlet connector 208 are respectively communicated with the cooling water channel.

[0035] Because the temperature rise has a greater impact on the vacuum degree under the ultra-high vacuum environment, the upper water cooling disc 202, the upper water cooling disc pipes 209 and the water cooling support rods 204 effectively isolate the heat loss into the ultra-high vacuum annealing system, thereby ensuring the use under the ultra-high vacuum environment.

[0036] The present embodiment is further provided with a temperature measuring and controlling thermocouple 1 on the upper shielding cover 201. One end of the temperature measuring and controlling thermocouple 1 is inserted into the upper shielding cover 201 and extends into the upper shielding cover 201. The other end of the temperature measuring and controlling thermocouple 1 is sealingly and fixedly connected with the vacuum chamber 9 through the mounting flange A 210 and is located outside the vacuum chamber 9. The temperature measuring and controlling thermocouple 1 of the present embodiment is a commercially available product purchased from Shenyang Dongda Sensing Technology Co., Ltd. and adopts a double-core armored structure (one spare is used), which not only ensures the vacuum degree of the ultra-high vacuum annealing system but also ensures that the temperature measuring and controlling thermocouple 1 is not affected in the working process.

[0037] As shown in FIG. 1, the temperature measuring and controlling thermocouple 1 is connected with a temperature measuring and controlling instrument 4 through a temperature measuring and controlling cable 3. Figure 1 , Figure 2 and Figures 5 to 8As shown, the lower tray assembly 3 of the embodiment comprises a lower shielding cover 301 and a lower tray support 302, the lower shielding cover 301 is fixed at the upper end of the lower tray support 302, the lower shielding cover 301 can be closed with the upper shielding cover 201 to lock the heat loss in the heating process and ensure the temperature index; the lower end of the lower tray support 302 is penetrated by the vacuum chamber 9 and connected with the lower tray transmission mechanism 4. The substrate holder 6 and the wafer 5 are located below the center of the main heating disc 203, and a quartz insulating plate 7 fixed on the lower shielding cover 301 is arranged at the lower part of the substrate holder 6; during operation, the wafer 5 is not conductive with other parts except the substrate holder 6, so that the substrate holder 6 can be subjected to radio frequency during the heating process, and after a certain amount of gas is introduced, the wafer 5 can be subjected to reverse sputtering cleaning.

[0038] The lower tray transmission mechanism 4 of the embodiment comprises a belt transmission assembly, a lead screw 405, a nut 406, a mounting flange B 409, a mounting frame 411 and a connecting plate 412, the mounting frame 411 is sealingly and fixedly connected to the vacuum chamber 9 through the mounting flange B 409, a lifting power source is fixed on the mounting frame 411 (the lifting power source of the embodiment is a servo motor 401), and the lead screw 405 is rotatably mounted on the mounting frame 411; the belt transmission assembly comprises a pulley A 402, a belt 403 and a pulley B 404, the output shaft of the servo motor 401 is connected with the pulley A 402, the lower end of the lead screw 405 is connected with the pulley B 404, the pulley A 402 is connected with the pulley B 404 through the belt 403, and the servo motor drives the lead screw 405 to rotate through the belt transmission assembly. The nut 406 is threadedly connected to the lead screw 405, one end of the connecting plate 412 is fixedly connected with the nut 406, and the other end of the connecting plate 412 is connected with the lower end of the lower tray support 302; a bellows 410 is sleeved on the lower end of the lower tray support 302 between the mounting flange B 409 and the connecting plate 412, the upper end of the bellows 410 is fixed on the mounting flange B 409, and the lower end of the bellows 410 is fixed on the connecting plate 412.

[0039] The embodiment further fixedly connects a guide column 408 to the mounting frame 411, the guide column 408 is arranged in parallel with the lead screw 405, and a guide sleeve 407 mounted on one end of the connecting plate 412 is sleeved on the guide column 408. During the lifting of the connecting plate 412 with the nut 406, the guide sleeve 407 and the guide column 408 play a guiding role.

[0040] The embodiment is provided with an air inlet 8 on the vacuum chamber 9, the air inlet 8 is in communication with the first interface of a three-way joint, the second interface of the three-way joint is in communication with an oxygen source through a pipeline and is provided with a solenoid valve on the pipeline, and the third interface of the three-way joint is in communication with an argon source through a pipeline and is provided with a solenoid valve on the pipeline. The introduction of oxygen into the vacuum chamber 9 can perform oxidation treatment on the wafer 5, and the introduction of argon into the vacuum chamber 9 can perform reverse sputtering treatment on the wafer 5.

[0041] This invention uses metal sealing and isolation components throughout. During hoisting, the mounting flange A210 can serve as a connection part with the hoisting mechanism.

[0042] The working principle of this invention is as follows:

[0043] This invention can meet the annealing and degassing requirements of wafers of 12 inches and below, and can be used in ultra-high vacuum environments above 10E-8Pa. The space temperature near wafer 5 can reach up to 800℃. When working stably, the hot vacuum degree is better than 2X10E-4Pa.

[0044] The upper shield 201 and the main heating plate 203 are installed in the upper part of the vacuum chamber 9 and remain fixed. The lower tray assembly 3 moves vertically up and down via the lower tray lifting mechanism 4 and the lifting power source, opening and closing with the upper shield 201. This allows for the placement and removal of 12-inch and smaller wafers in an ultra-high vacuum environment in conjunction with the integrated system. Specifically:

[0045] When the lower tray assembly 3 moves to the lower station, the wafer 5 is transferred to the substrate tray 6 by an external mechanism (such as a robot), and then the external mechanism is removed; when the lower tray assembly 3 moves upward to the upper station, the lower shield 301 and the upper shield 201 close, and the wafer 5 is completely sealed in the center position.

[0046] After the previous step is completed, the ultra-high vacuum annealing system completes a series of vacuuming operations. After reaching the base vacuum, the main heating plate 203 starts heating at the preset power. After 3 to 4 hours, it reaches 800°C, thus annealing the wafer 5.

[0047] During the heating process, the solenoid valve on the pipeline connected to the oxygen source can be opened and the solenoid valve on the pipeline connected to the argon source can be closed, allowing oxygen to be introduced into the vacuum chamber 9 through the inlet 8 to oxidize the wafer 5. Alternatively, after the substrate holder 6 is connected to the radio frequency power supply, the solenoid valve on the pipeline connected to the oxygen source can be closed and the solenoid valve on the pipeline connected to the argon source can be opened, allowing argon to be introduced into the vacuum chamber 9 to achieve a vacuum level of 100-200 Pa, thus performing backsplash cleaning on the wafer 5.

[0048] After a series of processes including heating are completed, the heating function of the ultra-high vacuum annealing system is turned off, and the lower tray assembly 3 moves downward to the next workstation. Since the entire ultra-high vacuum annealing system is still in a high-temperature range at this time, the wafer 5 should not be removed directly. Instead, a set amount of dry nitrogen gas is introduced at this point. Through gas displacement, the temperature of the wafer 5 can be quickly reduced to a temperature suitable for removal. Then, an external mechanism intervenes to remove the wafer 5, completing the entire process.

[0049] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A multi-functional heating tray for use in an ultra-high vacuum environment, characterized by: The application relates to a vacuum annealing device, which comprises an upper heating disc assembly (2), a lower tray assembly (3), a lower tray transmission mechanism (4) and a substrate support (6), wherein the upper heating disc assembly (2) and the lower tray assembly (3) are located in a vacuum chamber (9), the upper heating disc assembly (2) is fixed in the vacuum chamber (9), the lower tray transmission mechanism (4) is fixed outside the vacuum chamber (9), the substrate support (6) is fixed at the upper end of the lower tray assembly (3) and used for placing a wafer (5), the lower end of the lower tray assembly (3) is connected with a lifting power source through the lower tray transmission mechanism (4), the lifting power source drives the lower tray assembly (3), the substrate support (6) and the wafer (5) placed on the substrate support (6) to lift and realize opening and closing of the upper heating disc assembly (2), the upper heating disc assembly (2) comprises an upper shielding cover (201) and a main heating disc (203), the main heating disc (203) is fixed to the bottom surface of the upper shielding cover (201), and the main heating disc (203) performs annealing treatment on the wafer (5) placed on the substrate support (6) when the upper heating disc assembly (2) and the lower tray assembly (3) are closed.

2. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 1, wherein: An upper water cooling disc (202) is fixed to the top surface of the upper shielding cover (201), and the upper surface of the upper water cooling disc (202) is spirally laid with an upper water cooling disc pipe (209).

3. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 2, wherein: The two ends of the upper water cooling disc pipe (209) are respectively connected with a water cooling disc water inlet connector (205) and a water cooling disc water outlet connector (206), the water cooling disc water inlet connector (205) and the water cooling disc water outlet connector (206) are respectively sealed and fixed on the vacuum chamber (9) through mounting flanges A (210) and are located outside the vacuum chamber (9).

4. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 1, wherein: A plurality of water cooling support rods (204) are uniformly arranged on the outer edge of the upper shielding cover (201) in the circumferential direction, the bottom end of each water cooling support rod (204) is fixed to the upper shielding cover (201), the upper end of each water cooling support rod (204) extends out of the vacuum chamber (9), each water cooling support rod (204) is sealed and fixed on the vacuum chamber (9) through the mounting flanges A (210), and the upper end of each water cooling support rod (204) is respectively connected with a water cooling rod water inlet connector (207) and a water cooling rod water outlet connector (208).

5. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 1, wherein: A temperature measuring and controlling thermocouple (1) is further arranged on the upper shielding cover (201), one end of the temperature measuring and controlling thermocouple (1) is inserted into the upper shielding cover (201) and extends into the upper shielding cover (201), and the other end of the temperature measuring and controlling thermocouple (1) is sealed and fixed on the vacuum chamber (9) through the mounting flanges A (210) and is located outside the vacuum chamber (9).

6. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 1, wherein: The lower tray assembly (3) comprises a lower shielding cover (301) and a lower tray support (302), the lower shielding cover (301) is fixed to the upper end of the lower tray support (302), and the lower end of the lower tray support (302) extends out of the vacuum chamber (9) and is connected with the lower tray transmission mechanism (4).

7. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 6, wherein: The substrate holder (6) is provided with a quartz insulating plate (7) fixed on the lower shielding cover (301).

8. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 6, wherein: The lower tray transmission mechanism (4) comprises a belt transmission assembly, a lead screw (405), a lead nut (406), a mounting flange B (409), a mounting frame (411) and a connecting plate (412). The mounting frame (411) is sealingly and fixedly connected to the vacuum chamber (9) through the mounting flange B (409). The lifting power source is fixed on the mounting frame (411). The lead screw (405) is rotatably mounted on the mounting frame (411). The output end of the lifting power source is connected with the lead screw (405) through the belt transmission assembly to drive the lead screw (405) to rotate. The lead nut (406) is threadedly connected to the lead screw (405). One end of the connecting plate (412) is fixedly connected with the lead nut (406). The other end of the connecting plate (412) is connected with the lower end of the lower tray support (302). The lower end of the lower tray support (302) between the mounting flange B (409) and the connecting plate (412) is sleeved with a bellows (410). The upper end of the bellows (410) is fixed on the mounting flange B (409). The lower end of the bellows (410) is fixed on the connecting plate (412).

9. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 8, wherein: The mounting frame (411) is fixedly connected with a guide column (408). The guide column (408) is arranged in parallel with the lead screw (405). The guide column (408) is sleeved with a guide sleeve (407) mounted on one end of the connecting plate (412).

10. The multi-functional heating tray for use in an ultra-high vacuum environment according to claim 1, wherein: The vacuum chamber (9) is provided with an air inlet (8). The air inlet (8) is in communication with the first interface of a three-way joint. The second interface of the three-way joint is in communication with an oxygen source through a pipeline and is provided with a solenoid valve on the pipeline. The third interface of the three-way joint is in communication with an argon source through a pipeline and is provided with a solenoid valve on the pipeline.

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