Low-pressure gas supply device for ion implanter

Abstract

The utility model relates to a low-pressure gas supply device for an ion implanter. The low-pressure gas supply device comprises a gas conveying system and a control system, the gas conveying system comprises a PH3 pipeline, a BF3 pipeline and an argon pipeline, and the pipelines are connected with the vacuum pipeline through a confluence safety valve after confluence and are connected with the ion source chamber. The PH3 pipeline and the BF3 pipeline are respectively provided with an SDS low-pressure source gas cylinder as a gas source, are connected through a 1 / 4 VCR interface, and are equipped with a pressure gauge, a pressure sensor, a manual valve, a pneumatic control valve and a mass flow controller to accurately control the gas flow. The argon pipeline comprises a process pipeline and a purging pipeline, and the purging pipeline is connected into a PH3 pipeline and a BF3 pipeline, is controlled by a pneumatic control valve and is used for purging toxic gas before a gas cylinder is replaced. By adopting the low-pressure gas source and the mass flow controller, the high-pressure poison gas leakage risk is reduced, the flow control precision is improved to 1%, the maintenance safety is improved through the purging pipeline, and the ion injection device is suitable for various ion injection devices.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor equipment engineering technology, specifically to a low-pressure gas supply device for an ion implanter, which is suitable for the gas supply system of a high-current ion implantation equipment. Background Technology

[0002] Ion implantation is a key process in semiconductor manufacturing. By introducing a controlled number of impurities into a silicon substrate, its electrical properties are altered, thereby enabling the functional design of semiconductor devices. Ion implantation is typically performed within an ion implanter. Its core step involves delivering the required gaseous source from a gas cylinder to the ion source chamber, where the gas is ionized to generate an ion beam, which is then implanted into the silicon substrate. The stable supply and precise control of the gaseous source directly affect the accuracy and consistency of the ion implantation process; therefore, the gas supply system plays a crucial role in the ion implanter.

[0003] Traditional ion implanter gas supply systems mostly employ high-pressure gas cylinder supply. Taking the NV10-160 high-current ion implanter manufactured by ETON Corporation in 1983 as an example, its original gas supply system was a high-pressure system. Process gases (such as PH3 and BF3) were stored in high-pressure cylinders, with pressures reaching up to 700 psi. After flowing out of the high-pressure cylinder, the gas passed through a cylinder shut-off valve, then underwent initial pressure regulation via a pressure regulating valve with a pressure gauge and a control pneumatic valve. Subsequently, a needle valve regulated the gas flow rate, and finally, a manifold valve led into the ion source chamber to complete the gaseous source supply. While this high-pressure supply mode met basic process requirements at the time, it gradually revealed numerous problems in practical applications.

[0004] First, the use of high-pressure gas cylinders poses significant safety hazards. Both PH3 (phosphine) and BF3 (boron trifluoride) are highly toxic gases. High-pressure cylinders operate at 700 psi; in the event of a leak, the toxic gases can spread rapidly, posing a serious threat to the lives of operators. Furthermore, the interfaces and pipelines of high-pressure gas cylinders are prone to minor leaks due to aging or decreased sealing performance after prolonged use, further increasing safety risks. This is especially true in semiconductor manufacturing environments, where production lines typically operate continuously and operators frequently come into contact with equipment; any leak could lead to severe consequences.

[0005] Secondly, traditional gas supply systems are outdated and lack modern safety protection features. Taking the NV10-160 model as an example, its original system lacks toxic gas leak alarm and leak safety interlock functions. In the event of a gas leak, the system cannot promptly alarm or automatically shut off the gas supply, forcing operators to rely on manual inspection to detect the problem. This passive safety management approach significantly increases the probability of accidents. Furthermore, traditional systems are not designed with ease of maintenance in mind; for example, they lack purging lines, making it difficult to remove residual toxic gases when replacing gas cylinders or maintaining pipelines, increasing the risk of operator exposure to toxic gases.

[0006] Furthermore, the gas flow control methods in traditional systems have significant shortcomings. The original system used needle valves for flow regulation, but needle valves have low adjustment precision, resulting in unstable flow control and large fluctuations. This unstable flow control directly affects the stability of the ion beam, leading to poor process consistency. In semiconductor manufacturing, process consistency is a critical factor in ensuring product quality; flow fluctuations can cause performance differences between different batches, thus affecting device manufacturing yield. In addition, the mechanical structure of needle valves has a high failure rate during use, and frequent maintenance requirements further reduce equipment operating efficiency. Utility Model Content

[0007] In view of this, the purpose of this utility model is to solve the above problems and provide a low-pressure gas supply device for an ion implanter to reduce the risk of high-pressure toxic gas leakage, improve the stability of gas flow control, and enhance the safety and ease of maintenance of the system.

[0008] To achieve the above objectives, this utility model provides the following technical solution:

[0009] A low-pressure gas supply device for an ion implanter includes a gas delivery system and a control system, wherein the gas delivery system includes a PH3 pipeline, a BF3 pipeline, and an argon pipeline;

[0010] The PH3 pipeline, BF3 pipeline, and argon pipeline are connected to the vacuum pipeline via a junction safety valve, and then connected to the ion source chamber via the vacuum pipeline.

[0011] The PH3 pipeline and BF3 pipeline are respectively equipped with an SDS low-pressure source gas cylinder and a mass flow controller. The SDS low-pressure source gas cylinder is used as the gas source for process gases PH3 and BF3, respectively, and the gas flow is controlled by the mass flow controller.

[0012] The argon gas pipeline includes an argon gas process pipeline and a purging pipeline. The argon gas process pipeline is connected to the vacuum pipeline to transport argon gas as a process gas. The purging pipeline is connected to the PH3 pipeline and the BF3 pipeline respectively, and is used to purge toxic gases before changing the gas cylinder.

[0013] Furthermore, the PH3 pipeline also includes a pressure gauge, a pressure sensor, a manual valve, and a pneumatic valve; the SDS low-pressure source gas cylinder is connected to the vacuum pipeline through a 1 / 4VCR interface; the pressure gauge, pressure sensor, and mass flow controller are respectively located on three parallel branches; the two branches equipped with the pressure gauge and pressure sensor are respectively connected to the vacuum pipeline through manual valves; the branch equipped with the mass flow controller is equipped with a pneumatic valve, which is controlled by the control system.

[0014] Furthermore, the BF3 pipeline also includes a pressure gauge, a pressure sensor, a manual valve, and a pneumatic valve; the SDS low-pressure source gas cylinder is connected to the vacuum pipeline through a 1 / 4VCR interface; the pressure gauge, pressure sensor, and mass flow controller are respectively located on three parallel branches; the two branches equipped with the pressure gauge and pressure sensor are respectively connected to the vacuum pipeline through manual valves; the branch equipped with the mass flow controller is equipped with a pneumatic valve, which is controlled by the control system.

[0015] Furthermore, both the pressure sensor and the mass flow controller are connected to the control system.

[0016] Furthermore, the argon process pipeline is equipped with a manual valve, a pressure reducing valve, a pressure gauge, and a mass flow controller in sequence, and the control system controls the argon flow rate through the mass flow controller.

[0017] Furthermore, the purging pipeline is connected in parallel with the argon process pipeline, and a manual valve is provided in the purging pipeline for manual control of the purging operation.

[0018] Furthermore, the control system includes:

[0019] A high-precision gas flow controller and power module are connected to a mass flow controller to control the gas flow rate.

[0020] A photoelectric conversion circuit is connected to the pressure sensor and the mass flow controller respectively, and is used to collect pressure and flow signals;

[0021] A digital display screen, connected to the photoelectric conversion circuit, is used to display pressure and flow values, enabling digital monitoring of pressure and flow.

[0022] The beneficial effects of this utility model are as follows:

[0023] Firstly, this invention significantly reduces the safety risk of high-pressure toxic gas leaks by replacing traditional high-pressure cylinders with SDS (Safe Delivery Source) low-pressure gas cylinders in the PH3 and BF3 pipelines. Traditional high-pressure cylinders operate at 700 psi, posing a high risk of leakage. In contrast, the SDS low-pressure gas cylinder uses internal adsorption technology to reduce the gas pressure to a safe range. Even in the event of a leak, the gas diffusion rate is slow, greatly reducing the threat to operators. Furthermore, the SDS low-pressure gas cylinder is equipped with a 1 / 4VCR connector, whose sealing performance is superior to traditional CGA330 connectors, further reducing pipeline leakage rates and ensuring the safety of system operation.

[0024] Secondly, this invention significantly improves the control accuracy and stability of gas flow by introducing a mass flow controller (MFC) to replace the traditional needle valve. The flow regulation accuracy of a traditional needle valve is only about 5%, with significant fluctuations, while the mass flow controller achieves a control accuracy of up to 1%. It can precisely set and maintain the gas flow according to process requirements, reducing the impact of flow fluctuations on ion beam stability, thereby improving process consistency and product yield. Simultaneously, the mass flow controller achieves automated regulation through a control system, reducing errors and labor intensity from manual operation and improving equipment operating efficiency.

[0025] Furthermore, this invention incorporates an argon purging pipeline, significantly enhancing the system's maintenance safety and convenience. Connecting the purging pipeline to both the PH3 and BF3 lines allows for the effective removal of residual toxic gases from the pipelines before cylinder replacement, eliminating the risk of operator exposure to PH3 and BF3 during maintenance. This design not only ensures operational safety but also reduces downtime during maintenance, improving equipment efficiency.

[0026] Furthermore, this invention achieves digital monitoring of gas pressure and flow rate through the connection of a pressure sensor and a mass flow controller with the control system. The photoelectric conversion circuit collects pressure and flow signals in real time and displays them intuitively on a digital screen, enabling operators to monitor the system's operating status at any time, promptly detect abnormalities, and take appropriate measures, further improving the system's reliability and controllability.

[0027] Finally, this device, through optimized piping design, supports simultaneous supply of three gas sources: PH3, BF3, and argon. Its compact and flexible structure makes it suitable for various types of ion implantation equipment, demonstrating strong versatility and potential for widespread application. This comprehensive improvement provides a safer, more stable, and more efficient gas supply solution for ion implantation processes in semiconductor manufacturing.

[0028] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0030] Figure 1 This is a schematic diagram of the low-pressure gas supply device used in the ion implanter of this utility model.

[0031] Figure reference numerals: 1-SDS low-pressure source gas cylinder; 2-Manual valve; 3-Pressure sensor; 4-Pressure gauge; 5-Pneumatic control valve; 6-Mass flow controller; 7-Manifold safety valve; 8-Purge pipeline; 9-Pressure reducing valve; 10-Ion source chamber. Detailed Implementation

[0032] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0034] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] Example 1

[0036] Please see Figure 1 This embodiment provides a low-pressure gas supply device for an ion implanter. The device includes a gas delivery system and a control system. The gas delivery system consists of a PH3 pipeline, a BF3 pipeline and an argon pipeline.

[0037] The PH3 and BF3 pipelines have the same structure, both using SDS low-pressure gas cylinder 1 as the gas source. SDS low-pressure gas cylinder 1 is connected to the vacuum pipeline via a 1 / 4VCR interface. After the gas flows out, it first passes through manual valve 2. After manual valve 2, the pipeline splits into three parallel branches:

[0038] The first branch is equipped with a pressure gauge 4, which is connected to the vacuum line via a manual valve 2 to monitor gas pressure;

[0039] The second branch is equipped with a pressure sensor 3, which is connected to the vacuum line via a manual valve 2 to collect pressure signals;

[0040] The third branch is equipped with a pneumatic control valve 5 and a mass flow controller 6. The pneumatic control valve 5 is used to control the gas flow, and the mass flow controller 6 is used to precisely control the gas flow.

[0041] The three branches eventually converge through the manifold safety valve 7 and connect to the ion source chamber 10.

[0042] Argon gas pipelines are divided into argon gas process pipelines and purging pipelines.

[0043] The argon process pipeline uses an argon cylinder as the gas source. First, the switch is controlled by a manual valve, then the pressure is reduced by a pressure reducing valve 9, then the pressure is monitored by a pressure gauge, and finally the gas flow is controlled by a mass flow controller and delivered to the ion source chamber 10 via a manifold safety valve 7.

[0044] The purging line 8 is connected in parallel with the argon process line and is connected to the PH3 line and BF3 line respectively. The purging line 8 is equipped with a manual valve for manually controlling the purging operation. Before changing the gas cylinder, toxic gases in the PH3 and BF3 lines are removed by argon.

[0045] The control system includes a high-precision gas flow controller and power supply module, photoelectric conversion circuit, and digital display screen. Pressure sensors and the mass flow controller acquire pressure and flow signals through the photoelectric conversion circuit and transmit these signals to the digital display screen for digital monitoring of gas pressure and flow. The gas control valve achieves automated on / off control through the control system, ensuring the stability of gas delivery.

[0046] This device significantly reduces the risk of toxic gas leakage, improves gas flow control accuracy, and enhances maintenance safety by employing SDS low-pressure source gas cylinders, mass flow controllers, and purging pipelines. It is suitable for the gas supply needs of various ion implantation equipment.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A low-pressure gas supply device for an ion implanter, characterized in that: It includes a gas delivery system and a control system, wherein the gas delivery system includes PH3 pipeline, BF3 pipeline and argon pipeline; The PH3 pipeline, BF3 pipeline, and argon pipeline are connected to the vacuum pipeline via a junction safety valve, and then connected to the ion source chamber via the vacuum pipeline. The PH3 pipeline and BF3 pipeline are respectively equipped with an SDS low-pressure source gas cylinder and a mass flow controller. The SDS low-pressure source gas cylinder is used as the gas source for process gases PH3 and BF3, respectively, and the gas flow is controlled by the mass flow controller. The argon gas pipeline includes an argon gas process pipeline and a purging pipeline. The argon gas process pipeline is connected to the vacuum pipeline to transport argon gas as a process gas. The purging pipeline is connected to the PH3 pipeline and the BF3 pipeline respectively, and is used to purge toxic gases before changing the gas cylinder.

2. The low-pressure gas supply device for an ion implanter according to claim 1, characterized in that: The PH3 pipeline also includes a pressure gauge, a pressure sensor, a manual valve, and a pneumatic valve; the SDS low-pressure source gas cylinder is connected to the vacuum pipeline through a 1 / 4VCR interface; the pressure gauge, pressure sensor, and mass flow controller are respectively located on three parallel branches; the two branches equipped with the pressure gauge and pressure sensor are respectively connected to the vacuum pipeline through manual valves; the branch equipped with the mass flow controller is equipped with a pneumatic valve, which is controlled by the control system.

3. The low-pressure gas supply device for an ion implanter according to claim 1, characterized in that: The BF3 pipeline also includes a pressure gauge, a pressure sensor, a manual valve, and a pneumatic valve; the SDS low-pressure source gas cylinder is connected to the vacuum pipeline through a 1 / 4VCR interface; the pressure gauge, pressure sensor, and mass flow controller are respectively located on three parallel branches; the two branches equipped with the pressure gauge and pressure sensor are respectively connected to the vacuum pipeline through manual valves; the branch equipped with the mass flow controller is equipped with a pneumatic valve, which is controlled by the control system.

4. The low-pressure gas supply device for an ion implanter according to claim 2 or 3, characterized in that: The pressure sensor and mass flow controller are both connected to the control system.

5. The low-pressure gas supply device for an ion implanter according to claim 1, characterized in that: The argon process pipeline is equipped with a manual valve, a pressure reducing valve, a pressure gauge, and a mass flow controller in sequence. The control system controls the argon flow rate through the mass flow controller.

6. The low-pressure gas supply device for an ion implanter according to claim 1, characterized in that: The purging pipeline is connected in parallel with the argon process pipeline, and a manual valve is provided in the purging pipeline for manual control of the purging operation.

7. The low-pressure gas supply device for an ion implanter according to claim 2 or 3, characterized in that, The control system includes: A high-precision gas flow controller and power module are connected to a mass flow controller to control the gas flow rate. A photoelectric conversion circuit is connected to the pressure sensor and the mass flow controller respectively, and is used to collect pressure and flow signals; A digital display screen, connected to the photoelectric conversion circuit, is used to display pressure and flow values, enabling digital monitoring of pressure and flow.

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