A gas path purging device for ion implantation

Abstract

The utility model discloses a kind of gas path purging devices for ion implantation, it is related to the technical field of semiconductor preparation, it includes gas supply pipe, suction pipe, multiple first branch pipe, multiple second branch pipe and multiple special gas pipe;The inlet end of gas supply pipe is connected with gas supply component;The outlet end of suction pipe is connected with vacuum component;The one end of each first branch pipe is connected with gas supply pipe, the other end is connected with corresponding special gas pipe respectively, and first regulating valve and check valve are set on each first branch pipe;The one end of each second branch pipe is connected with suction pipe, the other end is connected with corresponding special gas pipe respectively, and second regulating valve is set on each second branch pipe.The gas path purging device provided by the utility model can realize simultaneous purging of multiple special gas pipes or purging of single special gas pipe, with high purging efficiency;It can prevent backflow of gas in special gas pipe, with simple overall structure, safety and reliability, and convenient maintenance and disassembly.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor fabrication technology, and more specifically, to a gas path purging device for ion implantation. Background Technology

[0002] Ion implanters utilize thermionic electrons generated by the filament in an ion source to bombard gas molecules under the influence of an electric field, causing them to ionize. The ionized gas becomes ions, and the positively charged ions are repelled by the positive voltage of the ion source anode and extracted from the extraction slit to form an ion beam. The desired ions are separated by a mass analyzer, and impurity ions are removed. The beam is then accelerated by an acceleration system to obtain specific energy. The beam direction is then adjusted by a parallelizing magnet, and finally, a scanning system controls the relative movement of the ion beam and the silicon wafer to achieve uniform implantation.

[0003] The gas used in an ion implanter is usually stored in a source gas box, which contains a variety of gases, including toxic gases such as BF3, ASH3, and PH3, as well as some flammable and explosive hazardous chemical gases. These hazardous chemicals will remain in the various gas delivery pipelines during use. When maintaining or replacing mass flow meters or gas cylinders, the gas delivery pipelines must be purged multiple times to prevent leakage of hazardous chemicals. The purging gas is usually an inert gas such as high-purity nitrogen or high-purity argon.

[0004] The existing purging methods are limited, requiring an external purging system to purge a single pipeline, which is very inconvenient to operate and cannot purge multiple pipelines simultaneously, resulting in low purging efficiency. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a gas path purging device for ion implantation to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows: A gas path purging device for ion implantation includes a gas supply pipe, a gas extraction pipe, a plurality of first branch pipes, a plurality of second branch pipes, and a plurality of special gas pipes, wherein each of the special gas pipes is connected to a first branch pipe and a second branch pipe respectively. The inlet end of the gas delivery pipe is connected to a gas delivery assembly for delivering purge gas. The outlet end of the extraction pipe is connected to a vacuum assembly; One end of each first branch pipe is connected to the air supply pipe, and the other end is connected to the corresponding special gas pipe. Each first branch pipe is equipped with a first regulating valve and a one-way valve. One end of each second branch pipe is connected to the air extraction pipe, and the other end is connected to the corresponding special gas pipe. Each second branch pipe is equipped with a second regulating valve.

[0007] Furthermore, the air delivery assembly includes a regulating pipe, the inlet end of which is connected to a purge air source, and the outlet end of which is connected to the air delivery pipe. A third regulating valve, a pressure sensor, and a pressure reducing valve are installed on the regulating pipe.

[0008] Two pressure sensors are provided, located on the front and rear sides of the pressure reducing valve respectively, and the third regulating valve is located on the side near the outlet end of the regulating pipe.

[0009] Furthermore, the purge gas source includes purge gas cylinders or plant-side gas sources.

[0010] Furthermore, a fourth regulating valve is provided on the evacuation pipe near the vacuum assembly.

[0011] Furthermore, the first regulating valve, the second regulating valve, the third regulating valve, and the fourth regulating valve are all diaphragm valves.

[0012] The beneficial effects of this utility model are as follows: The pneumatic purging device provided by this utility model can purge multiple special gas tubes simultaneously or a single special gas tube. The purging is rapid and can complete multiple purgings in a short time, with high purging efficiency. It also effectively prevents mutual interference between the various special gas pipes during purging, and prevents the gas contained in the special gas pipes from flowing back into the purging pipeline, thereby affecting the purity of the purging gas source. It occupies little space, has a wide range of applications, high adaptability, and can be used in various types of ion implanters. Its overall structure is simple, safe and reliable, and easy to maintain and disassemble. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model.

[0015] Figure 2 This is a structural schematic diagram of the air delivery component in this utility model.

[0016] Explanation of reference numerals in the attached figures: 1. Gas supply pipe; 2. Gas extraction pipe; 3. First branch pipe; 4. Second branch pipe; 5. Special gas pipe; 6. Gas supply assembly; 6a. Purge gas source; 6a1. Purge gas cylinder; 6a2. Plant maintenance gas source; 6b. Third regulating valve; 6c. Pressure sensor; 6d. Pressure reducing valve; 6e. Regulating pipe; 7. Vacuum assembly; 8. First regulating valve; 9. Check valve; 10. Second regulating valve; 11. Fourth regulating valve. Detailed Implementation

[0017] The structure provided by this utility model will be explained and described in detail below with reference to the accompanying drawings.

[0018] refer to Figure 1 and Figure 2 As shown, this embodiment specifically discloses a gas path purging device for ion implantation, including a gas supply pipe 1, a gas extraction pipe 2, multiple first branch pipes 3, multiple second branch pipes 4, and multiple special gas pipes 5. Each special gas pipe 5 is connected to a corresponding first branch pipe 3 and a second branch pipe 4. The inlet end of the special gas pipe 5 is connected to the corresponding special gas source, and the outlet end is directly connected to the process chamber in the ion implanter for atomic deposition. The inlet end of the gas supply pipe 1 is connected to a gas supply assembly 6 for supplying purge gas; The outlet end of the suction pipe 2 is connected to a vacuum assembly 7; One end of each first branch pipe 3 is connected to the air supply pipe 1, and the other end is connected to the corresponding special gas pipe 5. Each first branch pipe 3 is equipped with a first regulating valve 8 and a one-way valve 9. One end of each second branch pipe 4 is connected to the air extraction pipe 2, and the other end is connected to the corresponding special gas pipe 5. Each second branch pipe 4 is equipped with a second regulating valve 10.

[0019] That is, multiple first branch pipes 3 are connected to the air supply pipe 1 in sequence, and multiple second branch pipes 4 are connected to the air extraction pipe 2 in sequence; wherein, the end of the air supply pipe 1 can be directly connected to the inlet end of the last first branch pipe 3; the front end of the air extraction pipe 2 can be directly connected to the first second branch pipe 4.

[0020] In this embodiment, the gas supply component 6 serves as the gas source supply end, directly supplying purging gas to the gas supply pipe 1, providing a clean purging gas source for the entire device. The gas supply pipe 1 uniformly distributes the purging gas to multiple first branch pipes 2, realizing gas delivery from a single source to multiple paths, which can meet the simultaneous purging needs of multiple special gas pipes 5.

[0021] Each first branch pipe 2 corresponds to a special gas pipe 5. The first regulating valve 8 on the pipeline can independently control the opening and closing of the corresponding first branch pipe 2, as well as control the amount of purging gas entering the corresponding special gas pipe 5. It can adjust the purging intensity according to the degree of contamination and specification differences of the special gas pipe, so as to achieve purging on demand.

[0022] The one-way valve 9 is a key anti-pollution component. It only allows the purging gas to flow from the first branch pipe 3 to the special gas pipe 5, completely blocking the backflow of the purging gas and preventing residual special gas in the special gas pipe 5 from entering the gas supply pipe 1 and contaminating the main gas source or other unpurged special gas pipes 5.

[0023] The vacuum assembly 7 at the end of the extraction pipe 2 is used to provide negative pressure suction to extract the gas remaining after purging the special gas pipe and the process chamber; each second branch pipe 4 corresponds to a special gas pipe 5, and the second regulating valve 10 on the second branch pipe 4 can independently control the opening and closing of the corresponding second branch pipe 4.

[0024] When it is necessary to purge a certain special gas pipe 5, first control the opening of the first regulating valve 8 on the first branch pipe 3 connected to it. The purging gas enters the special gas pipe 5 that needs to be purged through the gas supply pipe 1 and the corresponding first branch pipe 3. After the purging is completed, close the first regulating valve 8, open the second regulating valve 10, and connect to the vacuum component 7 through the extraction pipe 2 to complete the extraction. At this time, one purging is completed.

[0025] It is understood that the device provided in this embodiment can also realize the simultaneous operation of multiple pipelines. For example, if it is necessary to purge three special gas pipes 5 at the same time, the first regulating valve 8 on the first branch pipe 3 corresponding to the three special gas pipes 5 can be opened at the same time.

[0026] In the illustrated embodiment, the air supply assembly 6 includes a regulating pipe 6e, the inlet end of which is connected to a purge air source 6a, and the outlet end of which is connected to an air supply pipe 1. A third regulating valve 6b, a pressure sensor 6c, and a pressure reducing valve 6d are installed on the regulating pipe 6e.

[0027] In this embodiment, two pressure sensors 6c are provided, located on the front and rear sides of the pressure reducing valve 6d respectively, and the third regulating valve 6b is located on the side near the outlet end of the regulating pipe 6e.

[0028] Among them, the purge gas source 6a provides the raw gas for purging, which includes purge gas cylinder 6a1 or plant-side gas source 6a2. That is, the gas supply end has different connection methods. The first method uses purge gas cylinder 6a1, such as nitrogen or argon gas; the second method can connect to plant-side gas source 6a2 and use the centralized gas supply of plant-side gas source 6a2. Different connection methods can be achieved by changing the corresponding connector, which is convenient and quick.

[0029] After the purge gas supplied by the purge gas source 6a enters the regulating pipe 6e, the pressure sensor at the front end of the pressure reducing valve 6d can display the incoming gas pressure value and detect the gas supply pressure in real time. The gas supply pressure is changed by adjusting the pressure reducing valve 6d. The pressure sensor value at the back end of the pressure reducing valve 6d is observed until the required purge pressure is reached. (If the pressure is too low, the purge will not be clean and there will be residual process gas; if the pressure is too high, the purge gas will open the regulating valves, which will damage the valves and connect the pipelines, causing pollution to the process gas source.)

[0030] In some embodiments, a fourth regulating valve 11 is provided on the suction pipe 2 near the vacuum component 7 to control the opening and closing of the suction pipe 2. That is, the fourth regulating valve 11 is located on the suction pipe 2 near the vacuum component 7, downstream of all the second branch pipes 4, and is the main control valve of the suction circuit. It can control the total negative pressure intensity in the suction pipe 2 as a whole, forming a double protection with multiple second regulating valves 10.

[0031] In this embodiment, the first regulating valve 8, the second regulating valve 10, the third regulating valve 6b, and the fourth regulating valve 11 are all diaphragm valves. Diaphragm valves have a simple structure, with the only vulnerable part being the diaphragm, making replacement convenient and cost-effective. Compared to traditional ball valves, they are more wear-resistant and corrosion-resistant, extending their service life and reducing the time and cost of frequent maintenance downtime when in prolonged contact with purging gases (especially process gases containing toxic or corrosive gases).

[0032] The following is a general explanation of the purging principle and process: The principle of the special gas purging circuit of the source gas box of the ion implanter is: by introducing inert gas (such as nitrogen or argon) to replace and dilute the special gas remaining in the source gas box and pipeline, the risk of cross-contamination of gas path is eliminated, while ensuring the safety of subsequent operation.

[0033] The purging process of the gas path purging device provided by this utility model includes two parts: a gas supply process and a gas extraction process. The entire purging device can be adapted to different types of ion implanters, occupies little space, has a simple structure, and is easy to use. The purging gas source has different connection methods. The first method uses a purging gas cylinder 6a1, such as nitrogen or argon gas. The second method connects to the plant's gas source 6a2, utilizing the plant's centralized gas supply. Different connection methods can be achieved simply by changing the corresponding connector, making it convenient and quick.

[0034] After the purge gas source 6a is connected to the purge gas, the pressure sensor 6c at the front end of the pressure reducing valve 6d can display the connected gas pressure value and detect the gas supply pressure in real time. The gas supply pressure can be changed by adjusting the pressure reducing valve 6d, and the value of the pressure sensor 6c at the rear end of the pressure reducing valve 6d can be observed until the required purge pressure is reached.

[0035] Single-line purging procedure: Open the third regulating valve 6b and the first branch pipe 3 (to... Figure 1The first regulating valve 8 (arranged from left to right) allows the regulated gas to enter the first special gas pipe to complete the gas delivery. A one-way valve 9 connects the first regulating valve 8 and the special gas pipe 5, ensuring that only the purging gas enters the special gas pipe 5 and preventing backflow of gas from the special gas pipe 5 into the first branch pipe 3, thus preventing contamination of the purging gas source. Then, the first regulating valve 8 and the third regulating valve 6b are closed, and the fourth regulating valve 11 and the second regulating valve 10 on the first second branch pipe 4 are opened, connecting the vacuum assembly 7 to complete the evacuation. This completes one purging cycle. As can be seen from the above description, opening and closing four regulating valves 6b, 8, 10, and 11 is sufficient to complete the purging process, which can be completed in a very short time, even within seconds, demonstrating extremely high purging efficiency and effectiveness. The purging of the second, third, Nth, and last special gas pipes is performed in the same manner.

[0036] Multi-line purging process: Open diaphragm valve 6b, and the purging gas enters the gas delivery pipe 1 under pressure. At this time, open the diaphragm valve on the corresponding first branch pipe of the line to be purged. This completes the multi-line gas delivery process. Because each line has a one-way valve 6d, the gas in the special gas pipe 5 will not flow back into the first branch pipe 3 and the gas delivery pipe 1. Moreover, there is no flow between each special gas pipe 5, which ensures the purity of different gases in each special gas pipe 5, thereby ensuring the accuracy of ions in the ion beam and improving the injection efficiency. Then, close the diaphragm valve on the corresponding first branch pipe in sequence, and open the diaphragm valve on the corresponding second branch pipe in sequence to complete the evacuation. The gas in the special gas pipe 5 is drawn away by the vacuum component 7 under the action of gas pressure, completing one purging of the multi-line special gas pipe 5. Then repeat the above operation to perform multiple thorough flushings in a short time.

[0037] In summary, the device provided by this utility model has the following functions: 1. Replacement of residual special gases: Inert gas enters the gas path through the purge inlet, creating positive pressure in the gas box and pipeline, which "pushes" out the residual special gases (such as borane, phosphine, etc.) after previous use from the exhaust port (the exhaust port is located on the process chamber and the process chamber is connected to a dry pump), thereby reducing the concentration of special gases.

[0038] 2. Dilution and purification: Inert gas is continuously introduced to further dilute any trace amounts of special gas that may remain in the gas path, ensuring that the gas composition in the gas path is mainly inert gas, and avoiding reactions caused by mixing different gases when the special gas is replaced later (such as corrosion and explosion risks).

[0039] 3. Pressure balancing assistance: By controlling the inert gas supply pressure, i.e., adjusting the pressure reducing valve at the purging source end, a slight positive pressure is maintained in the gas path to prevent outside air or impurities from entering the gas path, while ensuring a stable and thorough purging process.

[0040] Compared with existing technologies, this ion implantation gas path purging device has the following significant advantages: 1. Adjustable and stable purging pressure, with flexible and variable purging gas source; 2. It can simultaneously purge multiple special gas tubes or purge a single special gas tube; 3. Effectively prevents mutual interference between the various special gas pipes during purging, and prevents the gas contained in the special gas pipes from flowing back into the purging pipeline, thereby affecting the purity of the purging gas source; 4. Rapid purging, capable of completing multiple purging cycles in a short time, with extremely high purging efficiency and effectiveness; 5. It occupies little space, has a wide range of applications, and is highly adaptable, making it suitable for various types of ion implanters; 6. Simple structure, safe and reliable, easy to maintain and disassemble.

[0041] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and simple improvements made on the substantive content of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A gas path purging device for ion implantation, characterized in that, It includes an air supply pipe (1), an air extraction pipe (2), multiple first branch pipes (3), multiple second branch pipes (4) and multiple special air pipes (5), with each special air pipe (5) connected to a first branch pipe (3) and a second branch pipe (4); The inlet end of the gas delivery pipe (1) is connected to a gas delivery assembly (6) for delivering purge gas. The outlet end of the extraction pipe (2) is connected to a vacuum assembly (7); One end of each of the first branch pipes (3) is connected to the air supply pipe (1), and the other end is connected to the corresponding special air pipe (5). Each of the first branch pipes (3) is provided with a first regulating valve (8) and a one-way valve (9). One end of each second branch pipe (4) is connected to the air extraction pipe (2), and the other end is connected to the corresponding special gas pipe (5). Each second branch pipe (4) is equipped with a second regulating valve (10).

2. The pneumatic purging device according to claim 1, characterized in that, The air supply assembly (6) includes a regulating pipe (6e), the inlet end of which is connected to a purge air source (6a), and the outlet end of which is connected to the air supply pipe (1). A third regulating valve (6b), a pressure sensor (6c), and a pressure reducing valve (6d) are installed on the regulating pipe (6e).

3. The air purging device according to claim 2, characterized in that, Two pressure sensors (6c) are provided, located on the front and rear sides of the pressure reducing valve (6d) respectively, and the third regulating valve (6b) is located on the side near the outlet end of the regulating pipe (6e).

4. The pneumatic purging device according to claim 2, characterized in that, The purge gas source (6a) includes a purge gas cylinder (6a1) or a plant-side gas source (6a2).

5. The pneumatic purging device according to claim 2, characterized in that, The extraction pipe (2) is provided with a fourth regulating valve (11) near the vacuum assembly (7).

6. The pneumatic purging device according to claim 5, characterized in that, The first regulating valve (8), the second regulating valve (10), the third regulating valve (6b) and the fourth regulating valve (11) are all diaphragm valves.

Images