Gas interface, semiconductor process system and ion implantation system

Abstract

The utility model discloses a gas interface, a semiconductor process system and an ion implantation system. The gas interface comprises an electrically insulating connecting pipe, an input metal gas pipeline, an output metal gas pipeline and an input gas coupler. A process gas flows from an electrically grounded input metal gas line to an output metal gas line via an electrically insulated connecting tube. A plurality of couplings between the metal gas line and the connecting pipe are sealed by a plurality of gas couplings. Each gas coupler includes a sealing washer and a clamp that compresses the sealing washer between an end of each metal gas line and a corresponding end of the connecting pipe. Process gas is delivered to the semiconductor process tool via the output metal gas line. At least one operation is performed at a semiconductor process tool that utilizes both a process gas and a voltage of at least 2 kilovolts delivered to the process tool via an output metal gas line. The connecting tube can be sapphire. The sealing washers can be a plurality of polytetrafluoroethylene sealing washers.

Description

Technical Field

[0001] The present disclosure relates to a gas interface, a semiconductor process system, and an ion implantation system. Background Art

[0002] The following content relates to semiconductor process technology, ion implantation technology, high-voltage technology, toxic gas disposal technology, and related technologies. Summary of the Utility Model

[0003] According to some embodiments of the present disclosure, a gas interface includes: an electrically insulating connecting pipe; an input metal gas pipeline; an output metal gas pipeline; an input gas coupler between one end of the input metal gas pipeline and a first end of the connecting pipe, the input gas coupler including: a sealing gasket disposed between the end of the input metal gas pipeline and the first end of the connecting pipe, and a compression clamp including a first clamping member engaging the end of the input metal gas pipeline and a second clamping member engaging the first end of the connecting pipe, the first clamping member and the second clamping member being fixed together and abutting the sealing gasket between the end of the input metal gas pipeline and the first end of the connecting pipe; and an output gas coupler between one end of the output metal gas pipeline and a second end of the connecting pipe, the output gas coupler including: a sealing gasket disposed between the end of the output metal gas pipeline and the second end of the connecting pipe, and a compression clamp including a first clamping member engaging the end of the output metal gas pipeline and a second clamping member engaging the second end of the connecting pipe, the first clamping member and the second clamping member being fixed together and abutting the sealing gasket between the end of the output metal gas pipeline and the second end of the connecting pipe.

[0004] According to some embodiments of the present disclosure, a semiconductor process system includes: a semiconductor process tool; and the gas interface as described in the foregoing embodiments, wherein the input metal gas pipeline is connected to an electrically grounded gas supply source, and the output metal gas pipeline is connected to the semiconductor process tool.

[0005] According to some embodiments of the present disclosure, an ion implantation system includes: an ion implanter connected to an output metal gas pipeline; and a gas interface including: an electrically insulating housing; an electrically insulating connecting pipe disposed in the housing and fixed to the housing; an input gas coupler disposed in the housing and between one end of an input metal gas pipeline and a first end of the connecting pipe, the input gas coupler including: a sealing gasket disposed between the end of the input metal gas pipeline and the first end of the connecting pipe; and a compression clamp abutting the sealing gasket between the end of the input metal gas pipeline and the first end of the connecting pipe; and an output gas coupler disposed in the housing and between one end of the output metal gas pipeline and a second end of the connecting pipe, the output gas coupler including: a sealing gasket disposed between the end of the output metal gas pipeline and the second end of the connecting pipe; and a compression clamp abutting the sealing gasket between the end of the output metal gas pipeline and the second end of the connecting pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industry practice, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0007] Figure 1 A semiconductor process system is illustrated diagrammatically;

[0008] Figure 2 and Figure 3 is illustrated diagrammatically Figure 1 a perspective view of the gas interface of the semiconductor process system;

[0009] Figure 4 An isolation view of the connecting pipe, and a cross-sectional view of the input gas coupler and the output gas coupler are illustrated diagrammatically;

[0010] Figure 5 and Figure 6 is illustrated diagrammatically Figure 4 a perspective view of an embodiment of the output gas coupler, showing the case without fasteners ( Figure 5 ), and further showing the case without the first clamping member ( Figure 6 ).

[0011]

REFERENCE SIGNS

[0012] 10: Semiconductor process tool / Ion implanter

[0013] 12: Gas flow controller

[0014] 14: Gas tank

[0015] 16: Gas cylinder

[0016] 18: Gas supply cabinet

[0017] 20: Metal gas pipeline

[0018] 20E: End

[0019] 22: Gas interface

[0020] 24: Metal gas pipeline

[0021] 24E: End

[0022] 30: Connecting pipe

[0023] 32: Gas coupler

[0024] 34: Gas coupler

[0025] 36: Housing

[0026] 38: Purified gas exhaust device

[0027] 40: Sensor

[0028] 42: Support

[0029] 44: Restrictive flow orifice

[0030] 50: Purified gas inlet

[0031] 52: Purified gas outlet

[0032] 54: Fastener

[0033] 56: End

[0034] 58: End

[0035] 60: Gas pipe coil

[0036] 62: Pipe coupler

[0037] 64: Gas pipe coil

[0038] 66: Pipe coupler

[0039] 70: Sealing washer

[0040] 72: Clamping piece / Compression clamp

[0041] 72A: Piece

[0042] 72B: Piece

[0043] 74: Clamping piece / Compression clamp

[0044] 76: Fastener

[0045] 80: Fastener

[0046] 82: Annular seat

[0047] 84: Opening / perforation

[0048] 86: Opening

[0049] L: Length Detailed implementation manner

[0050] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and configurations are described below to simplify this disclosure. Of course, these components and configurations are merely examples and are not intended to be limiting. For example, in the following description, the formation of a first feature above or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features such that the first and second features are not in direct contact. In addition, this disclosure may repeat reference numerals and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself prescribe the relationship between the various embodiments and / or configurations discussed.

[0051] In addition, for ease of description, spatially relative terms such as "below", "beneath", "lower", "above", "upper", etc. may be used herein to describe the relationship of one component or feature to another component or feature as depicted in the figures. In addition to the orientation depicted in the figures, spatially relative terms are intended to encompass different orientations of the device during use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0052] Ion implantation is widely used in semiconductor process technologies, such as forming doped regions with high spatial accuracy and controllable doping levels. For example, ion implantation can be used to form buried doped layers of deep p-type wells (DPW) or deep n-type wells (DNW) with defined depths and thicknesses. For n-type doping of silicon via ion implantation, arsine (AsH3) or phosphine (PH3) can be used as process gases to provide arsenic (As) or phosphorus (P) dopants, respectively. In another application, silicon-on-insulator (SOI) wafers can be formed by the SIMOX method, in which a high dose of oxygen atoms is implanted at a controlled depth and thickness, followed by annealing to convert the implanted oxygen layer into silicon dioxide (SiO2). These are only some non-limiting illustrative applications.

[0053] Ion implantation tools include an ion source that receives a process gas (e.g., arsine or phosphine for n-type doping applications), ionizes the gas using, for example, a heating filament and an applied voltage, and accelerates the generated ions towards a target (e.g., a silicon wafer). Magnetic and electrostatic fields can be employed to perform functions such as mass separation to select the ion species for implantation, and ion beam formation and steering to enable scanning or otherwise controlling the spatial extent of one or more implantation regions. The ion energy can be controlled by the accelerator voltage, and the ion energy has a significant impact on the implantation depth. The flow rate of the process gas and the implantation time are some other settings that can control characteristics such as doping levels.

[0054] Although ion implanters are common in semiconductor manufacturing facilities (i.e., semiconductor fabs), they pose some safety challenges. Many of the process gases used in ion implantation are highly toxic. For example, the lethal concentration 50 (LC50) of arsine is approximately 80 to 200 parts-per-million (ppm), depending on the experimental non-human species, and industrial safety regulations typically limit it to below 10 ppm. Phosphine has similar high toxicity. The process gas disposal requirements for such toxic gases are very strict. For example, self-contained breathing apparatus (SCBA) is required during the installation or replacement of process gas cylinders, a continuously operating gas monitoring system is deployed, the leakage of dedicated and special fittings for gas valves and connectors, gas pipelines and valves is regularly inspected, and the leakage of fittings and valves is frequently inspected. Gas scrubbers suitable for the type of process gas used, employee safety training, including formulating evacuation procedures and providing professional training for emergency response personnel, etc.

[0055] In addition to the safety issues posed by the frequent use of toxic gases such as arsine or phosphine, ion implanters also generate high voltages such as for the ion accelerator components. Ion implanters can operate at high voltages of 60 to 80 kilovolts (kV) or even higher in some cases. Therefore, ion implanters pose an electric shock hazard to personnel.

[0056] The combined use of toxic process gases and high voltages in the operation of ion implanters presents further safety challenges. Since polymer or plastic pipes have insufficient sealing and are too prone to damage and are not allowed for handling such toxic gases, gas handling systems for toxic gases such as arsine or phosphine typically employ stainless steel or other metal pipes or conduits for the gas lines. Metal gas fittings are also used to ensure protection against process gas leakage. Gas supply cabinets containing arsine, phosphine, or other process gas cylinders and the downstream gas lines are electrically grounded to prevent electrostatic discharge (ESD) events. This means that the metal gas lines are at electrical ground (0 kV). In contrast, the ion implanter tool can be at a much higher voltage, for example, 60 to 80 kV in some cases.

[0057] In addition to the above safety issues, seismic resistance can be a further safety consideration. The force of a large earthquake or typhoon may damage or rupture gas fittings, resulting in gas leakage, which is particularly serious if the gas involved is a toxic gas such as arsine or phosphine.

[0058] Although the above safety context has been described with particular reference to ion implanter systems, similar issues may also arise in other types of semiconductor process tools that employ a combination of gas input, particularly but not limited to toxic gases, and high voltages. As some other examples, some types of plasma deposition systems and plasma etching systems can employ high voltages when converting source gases or etchant gases into plasma, and thus, these types of semiconductor process tools can similarly utilize high voltages and also receive process gases from an electrically grounded process gas supply source.

[0059] Semiconductor process apparatus embodiments are disclosed herein that provide improved gas handling to enable the safe delivery of one or more gases to a semiconductor process tool that employs high voltages. A gas supply box is also disclosed herein that is inserted between a gas supply cabinet and an ion implanter or other high voltage semiconductor process tool, where the gas supply box has an electrically insulating housing and one or more rigid, airtight, and electrically insulating tubes, such as one or more sapphire tubes, for gas connection between an electrically grounded process gas line and a high voltage semiconductor process tool. Gas fittings are also disclosed for connecting sapphire (or other rigid, airtight, and electrically insulating tubes) to metal gas lines on the electrically grounded side and the high voltage side. The gas supply box according to the embodiments disclosed herein provides advantages such as enabling gas connection during the ground-to-high voltage transition, providing easy engagement and disengagement of the gas connection for maintenance, compatibility with a continuous operation gas monitoring system (including the ability to apply positive pressure to the gas supply box), and good seismic resistance.

[0060] Reference Figure 1, a semiconductor processing system includes a semiconductor processing tool 10 (illustrative ion implanter 10), which is used to operate at high voltages, such as at least 20 kV (kilovolts) in some embodiments, or at least 60 kV in some embodiments, or at least 80 kV in some embodiments, or even higher voltages in some embodiments. In the case of the illustrative ion implanter 10, one or more high-voltage operations may include operations such as: exciting an electrostatic accelerator to accelerate ions of a process gas to generate high-energy ions for implantation into a silicon layer or wafer or other targets for purposes such as dopant implantation, forming an insulator layer of a silicon-on-insulator (SOI) wafer, etc. Gas flow control 12 in the form of pneumatic and / or electro-actuated valves, pneumatic and / or electrically operated mass flow controllers (MFCs), etc. is operated by an electronic ion implanter controller (not shown) to control the flow of process gas into the semiconductor processing tool 10 according to a process recipe or schedule. In some illustrative embodiments, the process gas may be a toxic gas, such as arsine or phosphine, and the gas flow control 12 is installed in a gas cabinet 14 to provide containment and early detection of any process gas leaks (to be described). The process gas is typically supplied in cylinders (also known as gas cylinders), such as the illustrative gas cylinder 16 disposed in a gas supply cabinet 18. Other types of process gas supply sources are considered, such as bubblers supplied by a carrier gas (such as nitrogen or argon). The illustrative gas cylinder 16 is typically connected to a regulator to control the flow of process gas out of the gas cylinder 16, and for toxic process gases, the gas supply cabinet 18 typically includes safety features, such as a continuously operating gas monitoring system, and may be electrically grounded to prevent electrostatic discharge (ESD) events. The input metal gas line 20 is connected from the gas cylinder 16 to a gas interface 22, and the gas interface 22 interfaces with an output metal gas line 24, which delivers the process gas to the semiconductor processing tool 10 (and more specifically, to its gas flow controller 12).

[0061] In operation, as mentioned, the ion implanter 10 performs at least one operation utilizing a high voltage, e.g., at least 20 kV in some embodiments. Since the output metal gas line 24 is conductive, this means that if an electrical fault occurs in the ion implanter 10, the output metal gas line 24 is at high voltage (HV), e.g., at least 20 kV in some embodiments, or at least potentially at high voltage. On the other hand, the input metal gas line 20 is connected to the gas cylinder 16 in the gas supply cabinet 18 and is at ground potential (0 volts). The gas interface 22 includes features that provide a firm electrical isolation between the input metal gas line 20 and the output metal gas line 24, while also ensuring that the process gas (as previously mentioned, which can be a toxic gas such as arsine or phosphine) flows safely from the input metal gas line 20 to the output metal gas line 24. To this end, the gas connection from the input metal gas line 20 to the output metal gas line 24 is via a connecting tube 30, which is electrically insulating and mechanically rigid. The input gas coupler 32 provides a gas-tight seal between the end of the input metal gas line 20 and the first end of the connecting tube 30, while the output gas coupler 34 provides a gas-tight seal between the end of the output metal gas line 24 and the second end of the connecting tube 30. Additionally, the gas interface 22 includes a housing 36, which is electrically insulating, and the connecting tube 30, the input gas coupler 32, and the output gas coupler 34 are disposed within the housing 36.

[0062] Continuing to refer Figure 1 , in some embodiments, a purge gas flows through the housing 36 of the gas interface 22, where the housing is non-leaking or nearly non-leaking (some leakage of the purge gas may be acceptable). The purge gas flows through the housing 36 of the gas interface 22 and through the gas box 14 of the ion implanter 10 to the top purge gas exhaust 38. The purge gas is not a process gas used in the semiconductor process performed by the ion implanter or other semiconductor processing tool 10; rather, the purge gas has a safety function and is used to contain and facilitate the detection of any leakage of the process gas. The purge gas can be, for example, nitrogen (N2) or other inert gases. A gas flow control 12 (e.g., pneumatic and / or electrically operated valves, MFCs, etc.) is disposed in the gas box 14, which is also non-leaking or nearly non-leaking, and the purge gas flows through the gas box 14 (again, some leakage of the purge gas may be acceptable). Leakage of the process gas is most likely to occur at valves, MFCs, gas couplers, etc. (rather than through continuous metal gas lines), and thus continuous monitoring of the gas interface 22 and the gas flow control 12 is important, especially when the process gas is toxic. In Figure 1In a semiconductor processing system, the purge gas typically flows upward through the housing 36 of the gas interface 22, through the gas box 14 containing the gas flow control 12, and into the purge gas exhaust device 38. A continuously operating gas monitoring system sensor 40 is disposed in the purge gas exhaust device 38 to detect the presence of toxic gases in the purge gas flowing through the purge gas exhaust device 38. For example, the gas monitoring system sensor 40 can be a sensor of a multi-point toxic gas monitoring system, such as an MDA Scientific toxic gas monitor, for detecting arsine and / or phosphine at very low concentrations (e.g., on the order of parts per million, ppm). Although not shown, the gas monitoring system can optionally include additional sensors located at other locations, such as additional sensors inside the housing 36 of the gas interface 22, inside the gas box 14, and / or inside the ion implanter 10.

[0063] For example, as previously mentioned, the process gas arsine, which is sometimes used as an n-type dopant source for doping silicon by ion implantation, has a lethal concentration 50% (LC50) of approximately 80 to 200 parts per million (ppm), and industrial safety regulations typically limit it to below 10 ppm. Due to the restricted flow of the purge gas through the housing 36 of the gas interface 22 and the gas box 14 of the ion implanter 10, the concentration of leaked arsine in the ambient air entering the workspace occupied by personnel is much less than the concentration of arsine in the purge gas flowing through the housing 36 and the gas box 14. In addition, the detection of arsine in the purge gas exhaust by the sensor 40 provides early detection of arsine leakage in the gas connector of the gas interface 22, or early detection of arsine leakage in other components of the valve, MFC, or gas flow control 12. In a typical safety configuration, the sensor 40 detecting arsine above (usually very low) concentration thresholds automatically triggers a shut-off valve (not shown) located near the gas cylinder 16 (e.g., inside the gas supply cabinet 18, such as just downstream of the regulator connected to the gas cylinder 16), and also activates an emergency evacuation alarm system including a flashing warning light and an audible evacuation alarm to ensure the safe evacuation of personnel from the area until the arsine leakage can be located and repaired.

[0064] In Figure 1In an illustrative example, the gas interface 22 is disposed between supports 42 of the gas box 14 of the ion implanter 10. These supports 42 may be electrically insulating to facilitate electrical isolation of the gas box 14, and the illustrative supports 42 include stress relief features to provide good seismic resistance in the event of an earthquake, typhoon, or other potential source of vibration interference. Placing the gas interface 22 within the supports 42 advantageously protects the gas interface 22 from accidental contact with personnel working around the ion implanter 10. An optional restrictive flow orifice (RFO) 44 may be provided to control the flow of process gas to the gas interface 22.

[0065] Reference is now made Figure 2 and Figure 3 for a further detailed description of the gas interface 22. The gas interface 22 is shown in the illustrative perspective view of Figure 2 and the same perspective view is shown in Figure 3 where the flow path of the process gas and the ground and HV are indicated by horizontal dashed lines. The illustrative gas box includes a housing 36 which is suitably made of an electrically insulating material such as a hard plastic material. The housing 36 is a structural element and thus should be a rigid body (e.g., hard plastic). It should be noted that the housing 36 is generally a completely (or almost completely) enclosed structure to contain the purge gas flowing therethrough; however, Figures 1 to 3 shows the housing 36 without the front panel and the rear panel to expose the internal components. A purge gas inlet 50 provided at the lower end (e.g., bottom or bottom surface) of the housing 36 provides the flow of purge gas into the housing 36, and a purge gas outlet 52 provided at the upper end (e.g., top) of the housing 36 provides the outflow of purge gas from the housing 36. Referring back briefly to Figure 1 , the purge gas outlet 52 may be connected to a purge gas inlet (not shown) of the gas box 14 of the semiconductor processing tool 10 so that the purge gas can flow from the housing 36 into the gas box 14 and thus flow into the purge gas exhaust device 38. The connecting pipe 30 is firmly held inside the housing 36 by a clamp or other fastener 54. In this way, the assembly of the housing 36 and the connecting pipe 30 forms a rigid assembly which helps to make the gas interface 22 earthquake resistant. The connecting pipe 30 has a first end 56 and a second end 58. In the illustrative example, the connecting pipe 30 is vertically oriented with the first end 56 close to the bottom where the input metal gas line 20 of the housing 36 is located and the second end 58 close to the top where the output metal gas line 24 of the housing 36 is located.

[0066] As best seen in Figure 2 , the input metal gas line 20 (which is typically at electrical ground or 0V potential as Figure 3Non-limiting illustrative embodiments (indicated diagrammatically in the figure) include a plurality of components. These include a gas tube coil 60 that provides seismic stress relief (again enhancing the seismic resistance of the gas interface 22) and various tube connectors 62 (labeled only in the figure). The input gas connector 32 provides a gas-tight seal between the end of the input metal gas line 20 and the first end 56 of the connecting tube 30. The output metal gas line 24 is at high voltage (HV), or at least potentially accidentally at high voltage in the event of an accidental electrical short, shunt, or other failure of the HV components of the semiconductor processing tool 10 (such as a short circuit in the electrostatic accelerator of the illustrative ion implanter 10, which can operate at an electrical HV of at least 2 kilovolts or 60 to 80 kV or higher in some embodiments). Non-limiting illustrative embodiments of the output metal gas line 24 also include a plurality of components, such as a gas tube coil 64 that provides seismic stress relief (again enhancing the seismic resistance of the gas interface 22) and various tube connectors 66 (labeled only in the figure). Figure 2 The figure is marked). Figure 2 The figure is marked).

[0067] More generally, the input metal gas line 20 and the output metal gas line 24 can typically be any suitable metal gas line, such as a stainless steel tube or conduit as one non-limiting illustrative example. Each of the metal gas lines 20 and 24 can be a single tube or conduit, or can include two or more tube or conduit segments interconnected by one or more suitable gas-tight connectors. Each of the metal gas lines 20 and 24 can optionally incorporate one or more components, such as a flow meter, a pressure sensor, a filter, a straight-through valve, etc.

[0068] Reference is now made to Figure 4 which shows an isolated view of the connecting tube 30 and cross-sectional views of the input gas connector 32 and the output gas connector 34. The input gas connector 32 connects the first end 56 of the connecting tube 30 to the end 20E of the input metal gas line 20. The output gas connector 34 connects the second end 58 of the connecting tube 30 to the end 24E of the output metal gas line 24. The input gas connector 32 and the output gas connector 34 have the same configuration in the illustrative example, and thus, the same reference numerals are used to label the same components of the two gas connectors 32 and 34.

[0069] The connecting tube 30 is made of an electrically insulating material and is rigid to provide seismic resistance. The illustrative connecting tube 30 is a one-piece tube, which advantageously avoids seams or joints at locations that could cause process gas leakage. In the illustrative example herein, the connecting tube 30 is a sapphire tube, where the term "sapphire" as used herein encompasses both natural sapphire and synthetic sapphire; in other words, the connecting tube comprises alumina (Al2O3) having a single crystal structure. Sapphire is advantageously a hard material. For example, synthetic sapphire has a Vickers hardness of about 15 to 17 GPa and a Mohs hardness of about 9. Sapphire also has a high resistivity, for example, in some embodiments, about 10 16 ohm-cm at room temperature. Other types of hard and electrically insulating materials may also be considered for use as the connecting tube 30.

[0070] The illustrative connecting tube 30 is a straight tube having a length L as shown in Figure 4 . The length L of the connecting tube 30 should be a length sufficient to ensure sufficient spacing between the end 56 of the connecting tube 30 and the second end 58 of the connecting tube 30 to avoid an arc or other electrical shunt or short circuit between the (at least possible) HV at the second end 58 and the ground potential (0 V) at the first end 56. The minimum value of the length L of the connecting tube 30 required to achieve this electrical isolation depends primarily on the magnitude of the HV (or possible HV) at the output metal gas line 24. Generally, as the maximum HV (or possible HV) on the output metal gas line 24 increases, the minimum length will increase to provide sufficient isolation. In some non-limiting illustrative embodiments, the length L of the connecting tube is at least 15 cm to provide the required electrical isolation; and in some embodiments (e.g., for higher HV), a longer minimum tube length of 20 cm or more is desired.

[0071] Each of the input gas connector 32 and the output gas connector 34 includes a sealing gasket 70. Thus, the input gas connector 32 includes a sealing gasket 70 disposed between the end 20E of the input metal gas pipeline 20 and the first end 56 of the connecting pipe 30; and the output gas connector 34 includes a sealing gasket 70 disposed between the end 22E of the output metal gas pipeline 24 and the second end 58 of the connecting pipe 30. The compression clamp provides compression of the sealing gasket 70 to ensure an airtight seal. In an illustrative example, the first clamping member 72 engages the end 20E of the input metal gas pipeline 20, and the second clamping member 74 engages the first end 56 of the connecting pipe 30. The first clamping member 72 and the second clamping member 74 are fixed together by a fastener 76 (e.g., an illustrative bolt or screw, or other type of fastener) to pull the end 20E of the input metal gas pipeline 20 and the first end 56 of the connecting pipe 30 together, thereby compressing the sealing gasket 70 between the end 20E of the input metal gas pipeline 20 and the first end 56 of the connecting pipe 30. Similarly, the first clamping member 72 engages the end 24E of the input metal gas pipeline 24, and the second clamping member 74 engages the second end 58 of the connecting pipe 30. The first clamping member 72 and the second clamping member 74 are fixed together by a fastener 76 (e.g., an illustrative bolt or screw, or other type of fastener) to pull the end 24E of the output metal gas pipeline 24 and the second end 58 of the connecting pipe 30 together, thereby compressing the sealing gasket 70 between the end 24E of the output metal gas pipeline 24 and the second end 58 of the connecting pipe 30.

[0072] In some non-limiting illustrative embodiments, the sealing gasket 70 may be a polytetrafluoroethylene (PTFE) gasket 70. Advantageously, PTFE is a softer material than the sapphire of the connecting pipe 30. For example, PTFE has a Vickers hardness of approximately 30 to 50 Mpa (compared to about 15 to 17 GPa for sapphire). Thus, the gasket 70 can be compressed against the ends 56 and 58 of the sapphire connecting pipe 30 without damaging the ends 56 and 58 to provide the desired airtight seal. In some embodiments, the PTFE gasket 70 may be made of Teflon TM (a special brand of PTFE). Instead of PTFE, the sealing gasket 70 may be made of another material that is soft enough to avoid damaging the ends 56 and 58 of the rigid connecting pipe 30. The sealing gasket 70 may generally include an electrically insulating material or a conductive material.

[0073] Reference Figure 5 and Figure 6 , a non-limiting illustrative embodiment of the output gas connector 34 is shown without a fastener 76 ( Figure 5 ), and is further shown without a first clamping member 72 (Figure 6 )。 As previously mentioned, the input gas connector 32 and the output gas connector 34 have the same configuration in the illustrative example, and thus Figure 5 and Figure 6 the gas connector of can also represent the input gas connector by inverting it. Starting from a particular reference Figure 5 , the first clamping member 72 can suitably be a single piece, such as a metal plate formed with a central opening, and the end 24E of the output metal gas pipeline 24 is welded or otherwise fixed in an airtight manner within the central opening.

[0074] On the other hand, in the Figure 5 and Figure 6 embodiments, a unified structure for accommodating the sapphire connection tube 30 is achieved by forming the second clamping member 74 into two pieces 72A and 72B, which are fixed together around the second end 58 of the sapphire connection tube 30 and are fixed around it by bolts or other fasteners (such as screws) 80 (also diagrammatically shown and labeled in Figure 4 ). As can be seen in the cross-sectional views of the input gas connector 32 and the output gas connector 34 shown in Figure 4 , the first end 56 and the second end 58 of the connection tube 30 each have an annular seat 82, and the second clamping member 74 engages into the annular seat 82 to fix the second clamping members 74 of the respective gas connectors 32 and 34 to the respective ends 56 and 58 of the connection tube 30. This is only an illustrative example of one way to fix the second clamping member 74 to the ends of the sapphire connection tube 30, and other methods can be considered.

[0075] In Figure 5 and Figure 6 , the fasteners 76 are omitted; however, the openings 84 of the first clamping member 72 into which the fasteners 76 engage are shown (see Figure 5 ) and the openings 86 of the second clamping member 74 (see Figure 5 and Figure 6 ). In the illustrative embodiment, the opening 84 of the first clamping member 72 can suitably be a perforation (optionally with a countersink to accommodate the bolt head), while the opening 86 of the second clamping member 74 is a suitable threaded hole. Then, each fastener 76 passes through the perforation 84 of the first clamping member 72 and is screwed into the aligned threaded opening 86 of the second clamping member 74 to fasten the clamping members 72 and 74 together. Figure 5 and Figure 6 The illustrative embodiments of include six perforations 84 of the first clamping member 72 and six respectively aligned threaded openings 86 of the second clamping member 74, which are arranged at 60-degree intervals around the circumference of the gas connector to provide a symmetric and distributed clamping force; however, different numbers of fasteners can be envisioned.

[0076] The first clamping member 72 and the second clamping member 74 can be made of any suitable rigid material, such as metal, hard plastic, etc. The first clamping member 72 and the second clamping member 74 do not need to be electrically insulated (for example, they can be made of metal).

[0077] The disclosed gas connectors 32 and 34 offer many advantages. It is effective for providing an airtight seal between a metal pipeline and the end of a sapphire or other electrically insulating connecting pipe 30. The gas connectors 32 and 34 can also be reused, that is, repeatedly connected and disconnected, with at most the replacement (usually at low cost) of the PTFE sealing washer 70 (because it will likely be deformed due to the compression applied by the compression clamps 72, 74, and thus the reused sealing washer may be prone to leakage). In addition to the second clamping member 74 that engages the end of the connecting pipe 30 benefiting from having a customized shape to effectively engage the annular seat 82 at the end of the connecting pipe 30, the gas connectors 32 and 34 can also be constructed from mostly off-the-shelf components. The gas connectors 32 and 34 are also rigid, thus further promoting the stability of the gas interface 22 relative to seismic events.

[0078] Return to reference Figures 1 to 3 , the illustrative gas interface 22 includes a single connecting pipe 30 that is suitable for providing the flow transfer of a process gas from an input metal gas pipeline 20 at an electrically grounded (0V) potential to an output metal gas pipeline 24 at a high voltage, while maintaining electrical isolation between the input metal gas pipeline 20 and the output metal gas pipeline 24. It should be understood that the gas interface 22 can alternatively include two, three, four, or more connecting pipes 30 with a similar structure to provide the flow transfer of two, three, four, or more different process gases.

[0079] In another variant embodiment, it is possible to consider including redundant connecting pipes 30 and suitable pneumatic or electro - actuated valve devices to switch the process gas from one connecting pipe 30 to another. For example, this redundancy can provide a redundant flow path for a toxic process gas (such as phosphine or arsine). If a leak occurs in the input gas connector 32 or the output gas connector 34 of the utilized connecting pipe 30 (as detected by the sensor 40), the flow path can be switched to the redundant connecting pipe 30 so that the semiconductor processing tool 10 can continue to operate.

[0080] In the following, some other embodiments will be described.

[0081] In a non-limiting illustrative embodiment, a gas interface includes: a connecting pipe, which is electrically insulating; an input metal gas pipeline; an output metal gas pipeline; an input gas connector that provides an airtight seal between an end of the input metal gas pipeline and a first end of the connecting pipe; and an output gas connector that provides an airtight seal between an end of the output metal gas pipeline and a second end of the connecting pipe. The input gas connector includes: a sealing gasket disposed between the end of the input metal gas pipeline and the first end of the connecting pipe; and a compression clamp including a first clamping member that engages the end of the input metal gas pipeline and a second clamping member that engages the first end of the connecting pipe, and the first clamping member and the second clamping member are fixed together to compress the sealing gasket between the end of the input metal gas pipeline and the first end of the connecting pipe. The output gas connector includes: a sealing gasket disposed between the end of the output metal gas pipeline and the second end of the connecting pipe; and a compression clamp including a first clamping member that engages the end of the output metal gas pipeline and a second clamping member that engages the second end of the connecting pipe, and the first clamping member and the second clamping member are fixed together to compress the sealing gasket between the end of the output metal gas pipeline and the second end of the connecting pipe. According to some embodiments of the present disclosure, the connecting pipe is a sapphire connecting pipe. According to some embodiments of the present disclosure, the sealing gaskets of the input gas connector and the output gas connector are a plurality of polytetrafluoroethylene sealing gaskets. According to some embodiments of the present disclosure, the sealing gaskets of the input gas connector and the output gas connector include a material that is softer than sapphire. According to some embodiments of the present disclosure, the gas interface further includes a housing, which is electrically insulating, and wherein the connecting pipe, the input gas connector, and the output gas connector are disposed within the housing. According to some embodiments of the present disclosure, the housing includes a purge gas inlet and a purge gas outlet for allowing a purge gas to flow through the housing. According to some embodiments of the present disclosure, the connecting pipe is fixed to the housing to form a shock-resistant rigid assembly. According to some embodiments of the present disclosure, the connecting pipe is a straight pipe having a length of at least 15 cm. According to some embodiments of the present disclosure, a semiconductor process system includes: a semiconductor process tool configured to operate at a voltage of at least 2 kV; and a gas interface as described in the foregoing embodiments, wherein the input metal gas pipeline is connected to an electrically grounded gas supply source, and the output metal gas pipeline is connected to the semiconductor process tool. According to some embodiments of the present disclosure, the housing of the gas interface is airtight and includes a purge gas inlet and a purge gas outlet for allowing a purge gas to flow through the housing, and the semiconductor process system further includes: an exhaust device connected to receive the purge gas after the purge gas passes through the purge gas outlet; and a gas monitoring system operatively coupled to the exhaust device and configured to detect a leak of a toxic gas into the purge gas. According to some embodiments of the present disclosure, the semiconductor process tool includes an ion implanter.According to some embodiments of the present disclosure, the input metal gas pipeline includes at least one of a flow meter, a pressure sensor, a filter, and a straight-through valve. According to some embodiments of the present disclosure, the output metal gas pipeline includes at least one of a flow meter, a pressure sensor, a filter, and a straight-through valve.

[0082] In a non-limiting illustrative embodiment, a method of operating a semiconductor processing tool includes the steps of: flowing a process gas from an electrically grounded input metal gas pipeline through an electrically insulating connecting pipe to an output metal gas pipeline, wherein the connection between the metal gas pipeline and the connecting pipe is sealed by a gas connector, each gas connector including a sealing gasket and a clamp that compresses the sealing gasket between the end of the respective metal gas pipeline and the corresponding end of the connecting pipe; delivering the process gas to the semiconductor processing tool via the output metal gas pipeline; and performing at least one operation at the semiconductor processing tool, the semiconductor processing tool utilizing both the process gas delivered to the processing tool via the output metal gas pipeline and a voltage of at least 2 kilovolts. According to some embodiments of the present disclosure, the connecting pipe is a sapphire connecting pipe. According to some embodiments of the present disclosure, the sealing gaskets of the gas connectors are a plurality of polytetrafluoroethylene sealing gaskets. According to some embodiments of the present disclosure, the connecting pipe and the gas connectors are disposed in an electrically insulating housing, and the method further includes: flowing a purifying gas through and out of the housing; and using a gas monitoring system to detect a leakage of a toxic gas into the purifying gas to monitor the purifying gas flowing out of the housing. According to some embodiments of the present disclosure, the process gas includes at least one of phosphine and / or arsine. According to some embodiments of the present disclosure, the semiconductor processing tool includes an ion implanter, and the at least one operation performed at the ion implanter includes: performing ion implantation by ionizing the process gas delivered to the ion implanter via the output metal gas pipeline into an ionized process gas and accelerating a plurality of ions of the ionized process gas using an electrostatic accelerator operating at the voltage of at least 2 kilovolts.

[0083] In a non-limiting illustrative embodiment, an ion implantation system includes: an ion implanter connected to receive a process gas from an output metal gas line; and a gas interface. The gas interface includes: a housing that is electrically insulating; a connecting pipe that is electrically insulating and disposed in the housing and fixed to the housing; an input gas coupler; and an output gas coupler. The input gas coupler is disposed in the housing and provides an airtight seal between an end of the input metal gas line and a first end of the connecting pipe. The input gas coupler includes: a sealing gasket disposed between the end of the input metal gas line and the first end of the connecting pipe; and a compression clamp that compresses the sealing gasket between the end of the input metal gas line and the first end of the connecting pipe. The output gas coupler is disposed in the housing and provides an airtight seal between an end of the output metal gas line and a second end of the connecting pipe. The output gas coupler includes: a sealing gasket disposed between the end of the output metal gas line and the second end of the connecting pipe; and a compression clamp that compresses the sealing gasket between the end of the output metal gas line and the second end of the connecting pipe. According to some embodiments of the present disclosure, the connecting pipe is a sapphire connecting pipe, and the gaskets of the input gas coupler and the output gas coupler are a plurality of polytetrafluoroethylene sealing gaskets. According to some embodiments of the present disclosure, the ion implantation system further includes a gas cylinder connected to the input metal gas line, and the gas cylinder contains arsine or phosphine. According to some embodiments of the present disclosure, the output metal gas line and the input metal gas line include at least one of a flow meter, a pressure sensor, a filter, and a direct-through valve.

[0084] In a non-limiting illustrative embodiment, a process gas flows from an electrically grounded input metal gas line through an electrically insulating connecting pipe to an output metal gas line. The connection between the metal gas line and the connecting pipe is sealed by a gas coupler. Each gas coupler includes a sealing gasket and a clamp that compresses the sealing gasket between the end of the respective metal gas line and the corresponding end of the connecting pipe. The process gas is delivered to a semiconductor processing tool via the output metal gas line. At least one operation is performed at the semiconductor processing tool, and the semiconductor processing tool utilizes both the process gas delivered to the processing tool via the output metal gas line and a voltage of at least 2 kV. The connecting pipe can be sapphire. The sealing gasket can be a polytetrafluoroethylene (PTFE) sealing gasket.

[0085] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages as the embodiments introduced herein. Those skilled in the art should also recognize that such equivalent constructs do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made therein without departing from the spirit and scope of the present disclosure.

Claims

1. A gas interface, characterized in that, Comprising: An electrically insulating connecting pipe; An input metal gas pipeline; An output metal gas pipeline; An input gas connector, between one end of the input metal gas pipeline and a first end of the connecting pipe, the input gas connector comprising: A sealing gasket, disposed between the end of the input metal gas pipeline and the first end of the connecting pipe, and A compression clamp, comprising a first clamping member engaging the end of the input metal gas pipeline and a second clamping member engaging the first end of the connecting pipe, the first clamping member and the second clamping member being fixed together and abutting the sealing gasket between the end of the input metal gas pipeline and the first end of the connecting pipe; and An output gas connector, between one end of the output metal gas pipeline and a second end of the connecting pipe, the output gas connector comprising: A sealing gasket, disposed between the end of the output metal gas pipeline and the second end of the connecting pipe, and A compression clamp, comprising a first clamping member engaging the end of the output metal gas pipeline and a second clamping member engaging the second end of the connecting pipe, the first clamping member and the second clamping member being fixed together and abutting the sealing gasket between the end of the output metal gas pipeline and the second end of the connecting pipe.

2. The gas interface according to claim 1, wherein The input metal gas pipeline comprises at least one of a flow meter, a pressure sensor, a filter and a straight-through valve.

3. The gas interface according to claim 2, wherein, The output metal gas pipeline comprises at least one of a flow meter, a pressure sensor, a filter and a straight-through valve.

4. The gas interface according to claim 1, characterized in that, Further comprising: An electrically insulating housing, wherein the connecting pipe, the input gas connector and the output gas connector are disposed within the housing.

5. The gas interface according to claim 4, characterized in that, The housing comprises a purifying gas inlet and a purifying gas outlet.

6. The gas interface according to claim 1, wherein The connecting pipe is a straight pipe having a length of at least 15 cm.

7. A semiconductor process system, characterized in that, Comprising: A semiconductor processing tool; And The gas interface according to claim 4, wherein the input metal gas pipeline is connected to an electrically grounded gas supply source, and the output metal gas pipeline is connected to the semiconductor processing tool.

8. An ion implantation system, characterized in that, Comprising: An ion implanter, connected to an output metal gas pipeline; and A gas interface, comprising: An electrically insulating housing; An electrically insulating connecting pipe, disposed within the housing and fixed to the housing; An input gas connector, disposed within the housing and between one end of an input metal gas pipeline and a first end of the connecting pipe, the input gas connector comprising: a sealing gasket, disposed between the end of the input metal gas pipeline and the first end of the connecting pipe; and a compression clamp, abutting the sealing gasket between the end of the input metal gas pipeline and the first end of the connecting pipe; and An output gas connector, disposed within the housing and between one end of the output metal gas pipeline and a second end of the connecting pipe, the output gas connector comprising: a sealing gasket, disposed between the end of the output metal gas pipeline and the second end of the connecting pipe; and a compression clamp, abutting the sealing gasket between the end of the output metal gas pipeline and the second end of the connecting pipe.

9. The ion implantation system according to claim 8, wherein, The output metal gas pipeline and the input metal gas pipeline include at least one of a flow meter, a pressure sensor, a filter, and a straight-through valve.

10. The ion implantation system according to claim 8, wherein, Further included is: A gas cylinder connected to the input metal gas pipeline.

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