Low-temperature cooling type stable ion source injection device

Abstract

The utility model provides a low-temperature cooling type stable ion source injection device, which comprises a shell, an ion beam current system and a cooling mechanism, the ion beam current system comprises a gas box, an ion source, a mass analyzer and an accelerating tube which are sequentially connected in the shell, and the gas box and the ion source generate ion beams. Impurity ions are screened out by the mass analyzer and then ejected out by the accelerating tube in an accelerating manner; a through hole is formed in the shell corresponding to an outlet of the accelerating tube; the cooling mechanism is arranged on the outer side of the shell and comprises a cooling table, a plurality of cooling fins and a cooling pipe, a containing part is arranged on the cooling table, the containing part is aligned with the through hole, the cooling fins are connected to the cooling table, the cooling pipe penetrates through the cooling fins, the cooling pipe is provided with a liquid inlet and a liquid outlet, and a cooling agent circulates in the cooling pipe so that the cooling table can be cooled. According to the technical scheme of the utility model, the wafer can be cooled before ion implantation so as to form a thicker amorphous layer and fewer range end defects.

Description

Technical Field

[0001] The utility model relates to the technical field of ion implantation equipment, in particular to a low-temperature cooling type stable ion source implantation device. Background Art

[0002] The electrical properties of semiconductor devices depend on the concentration of impurities doped in the semiconductor. In the process of semiconductor wafer manufacturing, in order to turn pure silicon with poor conductivity into a useful semiconductor, a small amount of impurities needs to be added to change its structure and conductivity. This process is called doping. Currently, there are two doping processes: high-temperature thermal diffusion and ion implantation. Ion implantation occupies a mainstream position. Its principle is to ionize an electrically neutral atom or molecule, and then inject the required ion beam into the wafer at a certain angle with a certain energy and dosage, thereby turning the single crystal silicon into an amorphous state.

[0003] The temperature of the wafer has a great influence on the ion implantation process, and the industry has long been researching it, but it has been brought up again by the process industry in recent years. Currently, ion implantation often uses room temperature ion implantation technology, and the ambient temperature during injection is generally around 20°C. However, at room temperature, the atomic lattice is in a higher energy state, and it is easier to restore the single crystal state after being destroyed by the injected ions. Therefore, the speed of amorphization is relatively slow, and the amorphous layer formed is relatively thin. In addition, the gaps (atoms) generated in this process are not easy to stay in the amorphous layer, and the defects at the range end are relatively high. Utility Model Content

[0004] In order to solve the problems in the above-mentioned background technology, the utility model provides a low-temperature cooling type stable ion source implantation device, which is intended to cool the wafer before ion implantation to form a thicker amorphous layer and fewer range end defects.

[0005] The utility model solves the technical problem by adopting a solution: a low temperature cooling type stable ion source implantation device, comprising:

[0006] shell;

[0007] An ion beam system, the ion beam system comprising a gas box, an ion source, a mass analyzer and an accelerating tube connected in sequence inside the housing, the gas box and the ion source generate an ion beam, and the impurity ions are screened out by the mass analyzer and then accelerated and ejected by the accelerating tube, and the housing is provided with a through hole corresponding to the outlet of the accelerating tube;

[0008] A cooling mechanism is arranged on the outside of the shell, and the cooling mechanism includes a cooling platform, a plurality of cooling fins and a cooling pipe. A receiving portion is arranged on the cooling platform, and the receiving portion is aligned with the through hole. The cooling fins are connected to the cooling platform, and the cooling pipes are passed through the cooling fins. The cooling pipes have a liquid inlet and a liquid outlet, and a coolant flows in the cooling pipes to cool the cooling platform.

[0009] In an embodiment of the present invention, the cooling pipe is provided with a coiled portion, and the coiled portion passes through the cooling fins.

[0010] In an embodiment of the present invention, a plurality of mounting grooves are formed at the bottom of the cooling platform corresponding to the cooling fins, and the cooling fins are plugged into the mounting grooves.

[0011] In an embodiment of the present invention, a plurality of cooling fins are arranged at equal intervals.

[0012] In an embodiment of the present invention, the cooling fins are made of aluminum alloy.

[0013] In an embodiment of the present invention, a process chamber is disposed outside the shell, and the cooling mechanism is disposed in the process chamber.

[0014] To sum up, the beneficial effects of the utility model are as follows: the technical solution of the utility model is to arrange a cooling mechanism in the process chamber, the cooling mechanism includes a cooling pipe with a coolant flowing therein, a plurality of cooling fins arranged at equal intervals, and a cooling table plugged into the cooling fins, the cooling pipe passes through the cooling fins to cool the cooling fins and the cooling table, and the wafer placed on the cooling table is also cooled, which can enable the wafer after ion implantation to form a thicker amorphous layer and fewer range end defects.

[0015] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of this embodiment;

[0017] Figure 2 is a schematic diagram of the cooling mechanism of this embodiment;

[0018] Figure 3 is a cross-sectional view of the cooling mechanism of this embodiment;

[0019] Figure 4 Schematic diagram of cooling tubes and cooling fins of this embodiment;

[0020] Figure 5 FIG. 4 is a schematic diagram of a cooling stage of this embodiment.

[0021] In the figure: 1. outer shell; 11. through hole; 12. process chamber; 2. ion beam system; 21. gas box; 22. ion source; 23. mass analyzer; 24. accelerating tube; 3. cooling mechanism; 4. cooling table; 41. accommodating portion; 42. mounting groove; 5. cooling fins; 6. cooling tube; 61. liquid inlet; 62. liquid outlet; 63. winding portion. DETAILED DESCRIPTION

[0022] In order to make the content of the utility model more clearly understood, the utility model is further described below based on specific embodiments in combination with the accompanying drawings.

[0023] It should be noted that the terms "center", "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like used herein to indicate directions or positional relationships are based on directions 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 device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. Unless otherwise specified, "plurality" means two or more.

[0024] Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood by specific circumstances.

[0025] like Figures 1 to 5As shown, the utility model proposes a low-temperature cooling type stable ion source implantation device, including a shell 1, an ion beam system 2 and a cooling mechanism 3. The ion beam system 2 includes a gas box 21, an ion source 22, a mass analyzer 23 and an accelerating tube 24 which are sequentially connected inside the shell 1. The gas box 21 and the ion source 22 generate an ion beam, which is accelerated and ejected by the accelerating tube 24 after impurity ions are screened out by the mass analyzer 23. The shell 1 is provided with a through hole 11 corresponding to the outlet of the accelerating tube 24; the cooling mechanism 3 is arranged on the outside of the shell 1, and the cooling mechanism 3 includes a cooling platform 4, a plurality of cooling fins 5 and a cooling tube 6. The cooling platform 4 is provided with a receiving portion 41, and the receiving portion 41 is aligned with the through hole 11. The cooling fin 5 is connected to the cooling platform 4, and the cooling tube 6 is penetrated by the cooling fin 5. The cooling tube 6 has a liquid inlet 61 and a liquid outlet 62. A coolant flows in the cooling tube 6 to cool the cooling platform 4.

[0026] It can be understood that the ion beam system 2 is a prior art, and only a brief introduction is given here. The gas box 21 is used to provide the gas to be ionized for the ion source 22. The thermal electrons generated in the ion source 22 bombard the gas molecules under the action of the electric field to ionize them. All positively charged ions are repelled by the positive pressure of the anode of the ion source 22 and are drawn out from a slit. At this time, the electrons in the plasma are repelled by the cathode and blocked, thereby forming an ion beam composed of positive ions; the thermal electrons bombarding the impurity source gas molecules will produce a variety of ions, each of which has a different mass-to-charge ratio. When passing through the mass analyzer 23, under the action of the magnetic force, the movement trajectory of the ions will be different, and the required impurity ions can be separated from the mixed ion beam; in order to enable the ions to obtain greater energy to meet the injection requirements, the positive ions must pass through the high voltage of the acceleration tube 24 after coming out of the mass analyzer 23 to obtain the required speed. The acceleration tube 24 is composed of a series of dielectric-isolated electrodes, and the negative voltage on the electrodes increases successively. When the positive ions enter the acceleration tube 24, each negative electrode accelerates the ions step by step. The higher the total voltage, the faster the movement speed of the ions, that is, the greater the kinetic energy.

[0027] The cooling mechanism 3 is arranged outside the shell 1, and is composed of a cooling tube 6, a cooling fin 5 and a cooling platform 4. A receiving portion 41 is arranged on the cooling platform 4 for placing the silicon wafer to be cooled. The receiving portion 41 is aligned with the through hole 11 of the shell 1, so that the ion flow ejected from the outlet of the accelerating tube 24 can be injected into the wafer. A plurality of cooling fins 5 are connected to the bottom of the cooling platform 4. The cooling fins 5 are thin sheet structures made of materials with good thermal conductivity, which can transfer heat more quickly. The cooling tube 6 penetrates the cooling fins 5. Liquid hydrogen, liquid helium, liquid nitrogen, liquid oxygen, liquid methane, liquid nitrous oxide and other optional coolants flow in the cooling tube 6. In this example, the cooling tube 6 is made of copper, which has the advantages of excellent thermal conductivity and corrosion resistance. When the coolant continuously enters the cooling tube 6 from the liquid inlet 61 and then flows out from the liquid outlet 62, the cooling fins 5 and the cooling platform 4 connected to the cooling fins 5 can be quickly cooled down, so that the silicon wafer is cooled to meet the process requirements.

[0028] like Figures 2 to 4 As shown, in one embodiment of the present application, the cooling pipe 6 is provided with a coiled portion 63 , and the coiled portion 63 passes through the cooling fin 5 .

[0029] It can be understood that the cooling tube 6 has a tortuous winding portion 63, which can, on the one hand, increase the length and surface area of ​​the pipe, making the contact area between the pipe and the cooling fins 5 larger, thereby improving the heat exchange efficiency with the cooling fins 5 and making the cooling process of the cooling platform 4 and the silicon wafer faster; on the other hand, it can make the cooling of the cooling platform 4 more uniform, avoiding uneven heat distribution, causing the local temperature of the silicon wafer to be too high or too low, thereby affecting the ion implantation process.

[0030] like Figures 3 to 5 As shown, in one embodiment of the present application, a plurality of mounting grooves 42 are provided at the bottom of the cooling platform 4 corresponding to the cooling fins 5 , and the cooling fins 5 are inserted into the mounting grooves 42 .

[0031] It can be understood that since silicon wafers have various sizes, the cooling table 4 needs to be replaced when cooling wafers of different sizes. In this example, a mounting groove 42 is provided at the bottom of the cooling table 4, which is connected to the cooling fins 5 by plugging, so that the cooling table 4 can be easily replaced or repaired; multiple mounting grooves 42 are connected to the cooling fins 5, which can make the connection between the cooling table 4 and the cooling fins 5 more secure and not easy to loosen, and on the other hand, increase the contact area between the cooling table 4 and the cooling fins 5, thereby improving the cooling efficiency.

[0032] like Figures 2 to 4 As shown, in one embodiment of the present application, a plurality of cooling fins 5 are arranged in an equidistant manner.

[0033] It can be understood that through the above-mentioned configuration, on the one hand, the cooling efficiency can be improved, and the multiple cooling fins 5 arranged equidistantly can effectively increase the total heat exchange surface area. More surface area means greater heat exchange capacity, so the entire system can be cooled more effectively; on the other hand, the cooling of the cooling platform 4 can be made more uniform, avoiding uneven heat distribution, causing the local temperature of the silicon wafer to be too high or too low, thereby affecting the ion implantation process.

[0034] like Figures 2 to 4 As shown, in one embodiment of the present application, the cooling fins 5 are made of aluminum alloy.

[0035] It can be understood that the use of aluminum alloy material to make the cooling fins 5 has the following advantages: excellent thermal conductivity, aluminum alloy has a high thermal conductivity, so that the cooling fins 5 can quickly conduct heat, which helps to improve the cooling efficiency of the silicon wafer; light weight and high strength, aluminum alloy is relatively light compared to other metals, and at the same time has high strength, which enables the cooling fins 5 to reduce the weight of the entire equipment while ensuring the cooling efficiency, and can also provide better support for the cooling platform 4; easy to process, aluminum alloy material is easy to process and form, and can be manufactured into cooling fins 5 of various shapes and sizes according to different usage requirements, which makes the aluminum alloy cooling fins 5 have certain flexibility in manufacturing and customization; low cost, compared with some other metal materials with good thermal conductivity, the price of aluminum alloy is relatively low, so the manufacturing cost is also low, which makes the aluminum alloy cooling fins 5 more competitive in large-scale production and application.

[0036] like Figure 1 As shown, in one embodiment of the present application, a process chamber 12 is disposed outside the housing 1 , and the cooling mechanism 3 is disposed inside the process chamber 12 .

[0037] It can be understood that the process chamber 12 is located below the through hole 11 of the outer shell 1, and the internal space is used to install the cooling mechanism 3. On the one hand, it can isolate the external heat and prevent the external heat from affecting the cooling efficiency. On the other hand, it can also increase safety and avoid the cooling mechanism 3 with extremely low temperature being directly exposed to the outside, thereby protecting the safety of personnel and equipment.

[0038] In summary, the beneficial effects of this embodiment are as follows: this embodiment arranges a cooling mechanism 3 in the process chamber 12, the cooling mechanism 3 includes a cooling pipe 6 with a coolant flowing therethrough, a plurality of cooling fins 5 arranged at equal intervals, and a cooling table 4 plugged into the cooling fins 5, the cooling pipe 6 passes through the cooling fins 5, so that the cooling fins 5 and the cooling table 4 are cooled, and the wafer placed on the cooling table 4 is also cooled, so that the wafer after ion implantation can form a thicker amorphous layer and fewer range end defects.

[0039] The embodiments described above are only preferred implementation modes of the present utility model and cannot be used to limit the protection scope of the present utility model. Any non-substantial changes and modifications made by technicians in this field on the basis of the utility model shall fall within the protection scope of the present utility model.

Claims

1. A low temperature cooling type stable ion source implantation device, characterized in that: include Housing (1); An ion beam system (2), the ion beam system (2) comprising a gas box (21), an ion source (22), a mass analyzer (23) and an accelerating tube (24) which are sequentially connected inside the housing (1); the gas box (21) and the ion source (22) generate an ion beam, and the impurity ions are screened out by the mass analyzer (23) and then accelerated and ejected by the accelerating tube (24); the housing (1) is provided with a through hole (11) corresponding to the outlet of the accelerating tube (24); A cooling mechanism (3), wherein the cooling mechanism (3) is arranged on the outside of the shell (1), the cooling mechanism (3) comprises a cooling platform (4), a plurality of cooling fins (5) and a cooling pipe (6), the cooling platform (4) is provided with a receiving portion (41), and the receiving portion (41) is aligned with the through hole (11), the cooling fins (5) are connected to the cooling platform (4), the cooling pipe (6) is passed through the cooling fins (5), the cooling pipe (6) has a liquid inlet (61) and a liquid outlet (62), and a coolant circulates in the cooling pipe (6) to cool the cooling platform (4).

2. The low temperature cooling type stable ion source implantation device according to claim 1, characterized in that: The cooling pipe (6) is provided with a coiled portion (63), and the coiled portion (63) passes through the cooling fin (5).

3. The low temperature cooling type stable ion source implantation device according to claim 2, characterized in that: A plurality of mounting grooves (42) are provided at the bottom of the cooling platform (4) corresponding to the cooling fins (5), and the cooling fins (5) are plugged into the mounting grooves (42).

4. The low temperature cooling type stable ion source implantation device according to claim 3, characterized in that: The plurality of cooling fins (5) are arranged at equal intervals.

5. The low temperature cooling type stable ion source implantation device according to claim 4, characterized in that: The cooling fins (5) are made of aluminum alloy.

6. The low temperature cooling type stable ion source implantation device according to any one of claims 1 to 5, characterized in that: A process chamber (12) is arranged outside the shell (1), and the cooling mechanism (3) is arranged inside the process chamber (12).

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