Chemical film deposition machine

Abstract

The utility model provides a chemical thin film deposition machine table which comprises a machine table main body, a chemical thin film deposition device and a chemical thin film deposition device, the tray is mounted in the cavity, and a wafer is placed in the tray; the base is mounted in the cavity and is positioned below the tray; and at least three gas nozzles, the gas nozzles are connected to a gas inlet pipeline, the gas inlet pipeline is installed on the cavity, and the gas nozzles are used for spraying clean gas to the lower surface of the wafer. According to the chemical film deposition machine provided by the utility model, the air cushion effect between the wafer and the base can be improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductors, in particular to a chemical film deposition machine. Background Art

[0002] The high aspect ratio process (HARP) high pressure process of the wafer can be applied in chemical mechanical polishing equipment, dry etching equipment, photolithography equipment, chemical thin film deposition equipment, etc. When the wafer is transferred to the base of the cavity of the equipment / machine, an air cushion effect will be generated between the base and the wafer, which may cause the uniformity of the film thickness on the wafer surface to deteriorate and affect the wafer quality. Therefore, there is room for improvement. Utility Model Content

[0003] The utility model aims to provide a chemical thin film deposition machine to improve the air cushion effect between a wafer and a base.

[0004] In order to solve the above technical problems, the utility model is realized by the following technical solutions:

[0005] The utility model provides a chemical thin film deposition machine, comprising:

[0006] The machine body includes a cavity;

[0007] A tray is installed in the cavity, and a wafer is placed in the tray;

[0008] A base, installed in the cavity and located below the tray; and

[0009] At least three gas nozzles are connected to an air inlet pipeline installed on the cavity, and the gas nozzles are used to spray cleaning gas onto the lower surface of the wafer.

[0010] In one embodiment of the utility model, the tray comprises:

[0011] A tray body is installed in the cavity; and

[0012] The tray sinking part is located inside the tray body, and the tray sinking part sinks toward the base.

[0013] In an embodiment of the present invention, in the vertical direction, the cross section of the tray is stepped.

[0014] In an embodiment of the present invention, the tray body is in the shape of a circular ring, the tray sinking portion is in the shape of a circular ring, and the outer edge of the tray sinking portion is connected to the inner edge of the tray body.

[0015] In one embodiment of the utility model, a through opening is formed in the central portion of the sinking portion of the tray, the area of ​​the through opening is larger than the area of ​​the upper surface of the base, and the area of ​​the through opening is smaller than the area of ​​the upper surface of the wafer.

[0016] In an embodiment of the present invention, the through opening is circular, and the central axis of the through opening is coaxially arranged with the central axis of the base.

[0017] In one embodiment of the utility model, the plurality of gas nozzles are evenly distributed along a circular path around the central axis of the base, the gas nozzles are fixed on the side walls of the cavity, the nozzle angles of the gas nozzles are in the range of 5° to 75°, the diameters of the gas nozzles are in the range of 2mm to 8mm, and in the vertical direction, the spacing between the gas nozzles and the base is in the range of 10mm to 30mm.

[0018] In an embodiment of the present invention, a lifting structure is further included, and the lifting structure is located between the machine body and the base.

[0019] In one embodiment of the utility model, at least one pressure relief pipe is further included. The pressure relief pipe is arranged on the cavity, and a throttle valve is arranged in the pressure relief pipe.

[0020] In one embodiment of the utility model, a controller is further included, wherein the controller controls the throttle valve to be gradually closed, and the controller controls the lifting structure to drive the base to approach / move away from the tray.

[0021] As described above, the utility model provides a chemical thin film deposition machine, and the unexpected effect is: at the end stage of the self-cleaning of the cavity, by spraying clean gas into the cavity, impurities such as multi-molecular adsorption layers attached to the inner wall of the cavity and the surface of the tray can be removed, and the air cushion effect between the lower surface of the wafer and the surface of the tray can be effectively improved, so that the film thickness uniformity of the surface of the wafer is better during the deposition process. During the deposition process, the air pressure inside the cavity is controlled by gradually increasing the pressure, so that the air pressure inside the cavity gradually increases, which can effectively improve the situation where the wafer is offset and slides. After the deposition is completed, by spraying clean gas into the cavity again, impurities such as water vapor and multi-molecular adsorption layers attached to the lower surface of the wafer and the surface of the base can be removed, which can effectively improve the suction ability between the wafer and the base, and effectively improve the situation of wafer sliding.

[0022] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A schematic diagram of a cleaning process in a chemical thin film deposition machine in an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of a tray in a chemical thin film deposition machine in one embodiment of the utility model;

[0026] Figure 3 It is a working schematic diagram of a throttle valve in a chemical thin film deposition machine in one embodiment of the utility model.

[0027] In the figure: 10, tray; 11, tray body; 12, tray sinking part; 13, opening; 20, base; 30, air inlet pipe; 40, gas nozzle; 50, wafer; 60, pressure relief pipe; 70, throttle valve; 80, cavity; 90, side wall. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] See also Figure 1 The utility model provides a chemical thin film deposition machine, which can be applied to a high aspect ratio process (HARP) high pressure process of a wafer 50 to deposit various film layers on the wafer 50, such as silicon oxide, silicon nitride, etc. The chemical thin film deposition machine may include a machine body, a tray 10, a base 20, an air intake pipe 30, a gas nozzle 40, a pressure relief pipe 6060, a throttle valve 7070, and a controller. The tray 10, the base 20, the air intake pipe 30, the gas nozzle 40, the throttle valve 70, and the controller may be arranged in / on the machine body to complete the deposition of various film layers on the wafer 50 through the cooperation of different structures.

[0030] In one embodiment of the utility model, the machine body may include a cavity 80 (Aligner), an exhaust structure, a gas control structure, a heating structure and other auxiliary structures. Among them, the cavity 80 may be a vacuum cavity 80 or a vacuum chamber, and the vacuum chamber is the main space for thin film deposition. The cavity 80 can usually be made of stainless steel and has good sealing performance. The exhaust structure can adopt a combination of a mechanical pump, a molecular pump and a root pump to extract the gas in the cavity 80 to maintain a high vacuum environment. The gas control structure can be used to control the gas flow and pressure in the cavity 80, and the gas control structure may include a gas flow controller, a pressure sensor, etc. Through the cooperation of the exhaust structure and the gas control structure, a high vacuum environment required for the deposition process can be provided.

[0031] In one embodiment of the utility model, the heating structure is used to provide the heating conditions required in the thin film deposition process. The heating structure may include a resistance heater, a temperature sensor, a temperature controller, etc. The resistance heater may be made of graphite or metal material, and can quickly and evenly heat the wafer 50 and the deposition material. The temperature sensor is used to measure the temperature in the cavity 80 and transmit the signal to the temperature controller for feedback control to achieve constant temperature control during the deposition process.

[0032] See also Figure 2 In one embodiment of the utility model, the tray 10 can be installed in the cavity 80 of the machine body. The shape of the tray 10 can be adapted to the shape of the wafer 50 to position the wafer 50 so that the wafer 50 can be deposited smoothly. The tray 10 may include a tray body 11 and a tray sinking portion 12. The tray sinking portion 12 may be located inside the tray body 11. The tray sinking portion 12 may sink in the direction of the base 20. The outer edge of the tray sinking portion 12 and the inner edge of the tray body 11 may contact each other, and then a step shape may be formed through the mutual cooperation of the two. That is, in the vertical direction, the cross-section of the tray 10 may be stepped so as to place the wafer 50 on the tray sinking portion 12.

[0033] See also Figure 2 In one embodiment of the utility model, the shape of the tray body 11 may not be limited. For example, the tray body 11 may be formed in an annular shape, and its inner wall as a whole may be formed in an annular shape. For another example, the tray body 11 may be formed in a regular polygonal shape, and its inner wall as a whole may be formed in a regular polygonal shape. The shape of the tray body 11 may be set according to actual needs, as long as the inner edge of the tray body 11 can be matched with the outer edge of the wafer 50 to place the wafer 50 on the tray sinking portion 12.

[0034] See also Figure 2In one embodiment of the present invention, the shape of the tray sinking portion 12 may not be limited. For example, the tray sinking portion 12 may be formed in a ring shape. For another example, the tray sinking portion 12 may be formed in a regular polygonal shape. The shape of the tray sinking portion 12 may be set according to actual needs, as long as its outer edge can be connected to the inner edge of the tray body 11 to place the wafer 50 on the tray sinking portion 12.

[0035] See also Figure 2 In one embodiment of the utility model, a through opening 13 may be formed on the central portion of the tray sinking portion 12. The central axis of the through opening 13 may be coaxially arranged with the central axis of the base 20. The shape of the through opening 13 may not be restricted. For example, the through opening may form a circular shape. For another example, the through opening 13 may form a regular polygonal shape. The shape of the through opening 13 may be set according to actual needs, as long as it can satisfy that when the wafer 50 is placed on the tray sinking portion 12, the lower surface of the wafer 50 can be exposed by the through opening 13. Among them, the area of ​​the through opening 13 needs to be larger than the area of ​​the upper surface of the base 20, and at the same time, the area of ​​the through opening 13 needs to be smaller than the area of ​​the upper surface of the wafer 50.

[0036] See also Figure 1 and Figure 2 In one embodiment of the present invention, the base 20 can be installed in the cavity 80 of the machine body through a lifting structure, and is located directly below the opening of the tray sinking part 12. That is, the lifting structure can be located between the machine body and the base 20. The lifting structure can drive the base 20 to approach / move away from the opening of the tray sinking part 12. The base 20 can pass through the opening to complete the transfer / placement of the wafer 50.

[0037] In one embodiment of the utility model, the lifting structure can be a screw (screw rod) mechanism driven by an electric motor, a cylinder driven by hydraulic or pneumatic pressure, or other types of lifting platforms. This lifting structure needs to be able to achieve precise control because the lifting structure affects the distance between the wafer 50 and the gas source, which has an important impact on the deposition process and the uniformity of the film layer. The lifting mechanism needs to work in conjunction with the overall control system of the machine to ensure that the wafer 50 remains in the optimal position during the deposition process. In different CVD systems, different types of lifting structures may be used, depending on the design of the machine and the requirements of the production process.

[0038] See also Figure 1In one embodiment of the utility model, the number of the air inlet duct 30 may be at least one, and the air inlet duct 30 may spray clean gas toward the inside of the cavity 80 to improve the air cushion effect. In this embodiment, a gas nozzle 40 may be provided on the air inlet duct 30, and the gas nozzle 40 may spray toward the opening direction of the tray sinking part 12. Of course, in order to facilitate the control of the opening and closing of the air inlet duct 30, a valve may also be provided in the air inlet duct 30.

[0039] In one embodiment of the present invention, the number of gas nozzles 40 may be at least three, and the gas nozzles are used to spray cleaning gas into the inner wall of the chamber 80, the lower surface of the wafer 50, the surface of the tray 10, and the surface of the base 20. Each gas nozzle 40 is evenly distributed along a circular path around the central axis of the base 20. Specifically, a plurality of gas nozzles 40 are arranged at equal angular distances on the periphery of the base 20, and each gas nozzle 40 is spaced at equal angles relative to adjacent gas nozzles 40 to form a symmetrical circumferential array to ensure that the cleaning gas can be fully distributed on the lower surface of the wafer 50.

[0040] For example, when the number of the gas nozzles 40 is three, the three gas nozzles 40 can be arranged at equal angular distances on the periphery of the base 20, and each gas nozzle 40 is separated by an angle of 120 degrees relative to the adjacent gas nozzles 40 to form a symmetrical circular array. The three gas nozzles 40 can form an equilateral triangle shape. For another example, when the number of the gas nozzles 40 is greater than three, the multiple gas nozzles 40 can form a regular polygon shape, and the gas nozzles 40 can be distributed on the endpoints of the regular polygon.

[0041] In one embodiment of the present invention, the gas nozzle 40 can be fixed on the side wall 90 of the cavity 80, for example, fixed on the pillar of the bottom side wall 90 of the cavity 80. The nozzle angle of the gas nozzle 40 can be in the range of 5° to 75°, for example, the angle can be 5°, 40°, 75°, etc. In the vertical direction, the spacing between the gas nozzle 40 and the base 20 can be in the range of 10mm to 30mm, for example, the spacing can be 10mm, 20mm, 30mm, etc. The diameter of the gas nozzle 40 can be in the range of 2mm to 8mm, for example, the diameter can be 2mm, 5mm, 8mm, etc.

[0042] See also Figure 3 In one embodiment of the utility model, during the deposition of various film layers on the wafer 50, it is necessary to increase the pressure inside the chamber 80 so that the internal environment of the chamber 80 can meet the deposition conditions. In this embodiment, at least one pressure relief pipe 60 can be provided on the chamber 80. A throttle valve 70 (gasnozzle) can be provided on the pressure relief pipe 60. The internal gas pressure of the chamber 80 can be adjusted by controlling the opening and closing angle of the throttle valve 70.

[0043] In one embodiment of the utility model, the throttle valve 70 is a valve used to control the flow of fluid, and the flow rate and pressure of the fluid are adjusted by changing the cross-sectional area of ​​the internal channel of the valve body. In this embodiment, the throttle valve 70 that is opened / closed in stages is designed to stay at different openings to achieve more precise control of the fluid flow. Among them, the valve of the throttle valve 70 can have a precise thread or cam mechanism, allowing the valve stem and the valve disc (the part inside the valve that controls the flow) to move in small increments, so that the valve can be set at multiple different positions, each position providing a different flow level. For other types of throttle valves 70, it has a clear stop or locking mechanism, and can have physical stop points at different opening positions. The operator can close or open the valve to these pre-set stop points as needed to control the fluid flow. For the throttle valve 70 of this embodiment, the controller can accurately control the opening of the valve. For example, a valve driven by a stepper motor or a servo motor can open or close the valve in stages according to a program.

[0044] In one embodiment of the present invention, the controller can be disposed on the machine body, and the controller can control the various structures in the chemical thin film deposition machine to cooperate with each other to complete the deposition. For example, the controller can control the lifting structure of the base 20, the throttle valve 70, the valve of the air intake pipe 30, etc. to work.

[0045] In one embodiment of the utility model, when a thin film is deposited in a chemical thin film deposition machine, for example, when silicon dioxide is deposited on a wafer 50, the silicon dioxide synthesized by esters has strong chemical adsorption, which is related to the presence of hydroxyl groups on its surface. The surface hydroxyl groups of silicon dioxide can combine with molecules in the form of hydrogen bonds to form a multi-molecular adsorption layer, which may then form a multi-molecular adsorption layer, i.e., impurities, on the surface of the inner wall of the cavity 80, the surface of the tray 10, and the surface of the base 20. If the multi-molecular adsorption layer is not cleaned, after a new wafer 50 is placed on the tray 10, an air cushion effect may be formed between the lower surface of the wafer 50 and the surface of the tray 10, resulting in poor uniformity of the film thickness on the surface of the wafer 50 during the deposition process.

[0046] In one embodiment of the utility model, at the end of the self-cleaning stage of the chemical thin film deposition machine, the controller can control the valve of the air inlet pipe 30 to open, and the cleaning gas can be sprayed into the cavity 80 through the gas nozzle 40 of the air inlet pipe 30. After the cleaning gas is blown into the cavity 80, the multi-molecular adsorption layer on the surface of the inner wall of the cavity 80, the surface of the tray 10, and the surface of the base 20 can be cleaned to remove the multi-molecular adsorption layer. Specifically, the cleaning gas can be an inert gas, such as a mixed gas of nitrogen (Nitrogen) and helium (Helium). Nitrogen and helium have small molecular volume, low air viscosity, low surface tension, good diffusivity, stable chemical properties, and easy flow. When nitrogen and helium come into contact with the multi-molecular adsorption layer, they can promote the breakage of the surface hydroxyl bonds of the multi-molecular adsorption layer through impact, which can effectively reduce the surface adsorption capacity of the multi-molecular adsorption layer and effectively improve the air cushion effect. The reaction conditions of the cleaning gas may be: the gas pressure is in the range of 10 tor to 700 tor, the gas flow rate is in the range of 0 ksccm to 40 ksccm, the temperature is in the range of 100°C to 600°C, and the time may be set according to actual needs. For example, the gas pressure may be 10 tor, 400 tor, 700 tor, etc. The gas flow rate may be 10 ksccm, 20 ksccm, 40 ksccm, etc. The temperature may be 100°C, 350°C, 600°C, etc., and the time may be 10 min, 20 min, 30 min, etc.

[0047] In one embodiment of the utility model, after the processing of the multi-molecular adsorption layer is completed, a new wafer 50 can be placed on the tray 10 through the base 20 to complete the deposition. During the deposition process, since the inside of the cavity 80 needs to be in a high-pressure environment, it is necessary to increase the pressure inside the cavity 80. If the pressure increase speed inside the cavity 80 is too fast, it may cause the wafer 50 to deviate from the slide, causing the wafer 50 to slide, resulting in a deterioration in the uniformity of the film thickness on the surface of the wafer 50, affecting the quality of the wafer 50. In this embodiment, the air pressure inside the cavity 80 can be gradually increased by gradually increasing the pressure, which can improve the situation where the wafer 50 deviates from the slide.

[0048] In one embodiment of the utility model, for the original chemical thin film deposition machine, during the pressure increase process, the controller will adjust the opening and closing angle of the throttle valve 70 from 90° to 0° within a unit time, thereby completing the pressure increase. In the present application, the controller can control the opening and closing angle of the throttle valve 70 on the pressure relief pipe 60 to be gradually closed, so that the air pressure inside the cavity 80 gradually increases. That is, the controller can be configured to set a plurality of consecutive closing stages, and in each closing stage, the opening and closing angle of the throttle valve 70 is controlled to be closed to a preset angle, wherein a time interval is set between two adjacent closing stages.

[0049] In one embodiment of the utility model, specifically, the closing stage of the throttle valve 70 can be set to several stages. For example, the first stage can be to adjust its opening and closing angle from 90° to 60°, the second stage can be to adjust its opening and closing angle from 60° to 30°, and the third stage can be to adjust its opening and closing angle from 30° to 0°, and the time interval can be one unit time. During the first stage, one unit time can be consumed. After completing the first stage, you can wait for one unit time before entering the second stage. At this time, the time spent on adjusting the opening and closing angle of the throttle valve 70 from 90° to 0° can be five unit times. Compared with the original chemical thin film deposition machine, the boosting process is slow, which can effectively improve the situation where the wafer 50 has an offset slide.

[0050] In one embodiment of the utility model, after the thin film deposition of the wafer 50 is completed, impurities such as water vapor and multi-molecule adsorption layer may be attached to the lower surface of the wafer 50 and the surface of the base 20. When the wafer 50 needs to be lifted from the tray 10 by the base 20 for transportation, the presence of impurities such as water vapor and multi-molecule adsorption layer on the contact surface between the base 20 and the wafer 50 may cause unstable attraction between the two, and there is a situation that the wafer 50 slips. Therefore, after the thin film deposition of the wafer 50 is completed, the controller can control the valve of the air inlet pipe 30 to open again, and the gas nozzle 40 can spray toward the lower surface of the wafer 50 and the surface of the base 20. The surface hydroxyl bond of the multi-molecule adsorption layer can be broken by impact, and the impurities such as water vapor attached to the lower surface of the wafer 50 and the surface of the base 20 can be cleaned, thereby effectively improving the attraction ability between the wafer 50 and the base 20, and effectively improving the situation that the wafer 50 slips. After the cleaning is completed, the controller can control the base 20 to pass through the opening of the tray 10 to transport the wafer 50.

[0051] It can be seen that in the above scheme, the unexpected effect is: at the end of the self-cleaning stage of the cavity, the impurities such as the multi-molecular adsorption layer attached to the inner wall of the cavity and the surface of the tray can be removed by spraying clean gas into the cavity, which effectively improves the air cushion effect between the lower surface of the wafer and the surface of the tray, so that the film thickness uniformity of the surface of the wafer is better during the deposition process. During the deposition process, the air pressure inside the cavity is controlled by gradually increasing the pressure, so that the air pressure inside the cavity gradually increases, which can effectively improve the situation where the wafer deviates and slides. After the deposition is completed, by spraying clean gas into the cavity again, impurities such as water vapor and multi-molecular adsorption layers attached to the lower surface of the wafer and the surface of the base can be removed, which can effectively improve the suction ability between the wafer and the base, and effectively improve the situation of wafer sliding.

[0052] The embodiments of the utility model disclosed above are only used to help illustrate the utility model. The embodiments do not describe all the details in detail, nor do they limit the utility model to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the utility model, so that technicians in the relevant technical field can well understand and use the utility model. The utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A chemical thin film deposition machine, characterized in that: include: The machine body includes a cavity; A tray is installed in the cavity, and a wafer is placed in the tray; A base, installed in the cavity and located below the tray; as well as At least three gas nozzles are connected to an air inlet pipeline installed on the cavity, and the gas nozzles are used to spray cleaning gas onto the lower surface of the wafer.

2. The chemical thin film deposition machine according to claim 1, characterized in that: The tray comprises: A tray body is installed in the cavity; and The tray sinking part is located inside the tray body, and the tray sinking part sinks toward the base.

3. The chemical thin film deposition machine according to claim 2, characterized in that: In the vertical direction, the cross section of the tray is stepped.

4. The chemical thin film deposition machine according to claim 2, characterized in that: The tray body is in the shape of a circular ring, the tray sinking portion is in the shape of a circular ring, and the outer edge of the tray sinking portion is connected to the inner edge of the tray body.

5. The chemical thin film deposition machine according to claim 4, characterized in that: A through opening is formed in the central portion of the tray sinking portion, the area of ​​the through opening is larger than the area of ​​the upper surface of the base, and the area of ​​the through opening is smaller than the area of ​​the upper surface of the wafer.

6. The chemical thin film deposition machine according to claim 5, characterized in that: The through opening is circular, and the central axis of the through opening is coaxially arranged with the central axis of the base.

7. The chemical thin film deposition machine according to claim 1, characterized in that: The plurality of gas nozzles are evenly distributed along a circular path around the central axis of the base, the gas nozzles are fixed on the side wall of the cavity, the nozzle angle of the gas nozzles is in the range of 5° to 75°, the diameter of the gas nozzles is in the range of 2mm to 8mm, and in the vertical direction, the spacing between the gas nozzles and the base is in the range of 10mm to 30mm.

8. The chemical thin film deposition machine according to claim 1, characterized in that: It also includes a lifting structure, which is located between the machine body and the base.

9. The chemical thin film deposition machine according to claim 8, characterized in that: It also includes at least one pressure relief pipeline, which is arranged on the cavity and has a throttle valve in it.

10. The chemical thin film deposition machine according to claim 9, characterized in that: The device also includes a controller, wherein the controller controls the throttle valve to be gradually closed, and the controller controls the lifting structure to drive the base to approach / move away from the tray.

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