Air supply system for ion implanter

Abstract

The invention relates to an air supply system for an ion implanter. The air supply system comprises a metal chamber, an electric insulation box, a hard insulation pipe fitting and a flexible pipe fitting, a first pipeline and a second pipeline are arranged in the metal chamber, and the bottom of the metal chamber is fixed on the floor through a plurality of electrical insulating parts; the electrical insulation box is hung on one outer side of the metal chamber, the hard insulation pipe fitting is arranged in the electrical insulation box, one end of the hard insulation pipe fitting is connected with the second pipeline penetrating out of the outer wall of the metal chamber, and the other end of the hard insulation pipe fitting is connected to the flexible pipe fitting penetrating into the electrical insulation box. The electrical insulation box is hung on one side of the metal chamber, so that the doped gas needs to be high-pressure gas in order to prevent the gas in the hard insulation pipe fitting from being influenced by high voltage connected with the metal chamber to generate electrolytic ionization. And the hard insulating pipe fitting is connected with the flexible pipe fitting, so that external vibration energy can be absorbed.

Description

[0001] Divisional application information

[0002] This application is a divisional application of the invention patent application filed on May 9, 2019, with application number 201910383725.6 and invention name “Gas supply system for ion implanter”. Technical Field

[0003] The present invention relates to a gas supply system for an ion implanter, and more particularly to a gas supply system capable of remotely transporting gas for the ion implanter. Background Art

[0004] Ion implanters used in semiconductor equipment factories contain multiple reaction chambers, each of which uses different dopant gases depending on the product process recipe. These dopant gases dissociate under high voltage and are toxic to humans. These dopant gases are pre-filled and placed in a metal chamber within the ion implanter. These chambers are connected to piping within the chamber, which delivers the dopant gases to the ion implanter. This chamber is electrically connected to a high voltage source, meaning it is connected to the high potential of the source. Multiple electrical insulators are also installed between the bottom of the chamber and the floor to prevent a high voltage differential from forming within the chamber.

[0005] Due to the limited capacity of gas cylinders, if the usage of each reaction chamber in the ion implanter during the process is not properly controlled, the reaction chamber will be exhausted and the process will be forced to stop, resulting in losses. Therefore, many semiconductor equipment manufacturers have begun to develop how to connect the pipelines of the ion implanter to a remote large-scale storage dopant gas source to ensure a safe gas supply. Figure 6 As shown, a gas transmission device is provided, in which an electrically insulating tube 72 and a metal corrugated tube 73 connected in series are arranged between a metal chamber 70 and a remote large-volume dopant gas storage chamber 71. The metal corrugated tube 73 can absorb external vibration energy due to its better ductility, thereby avoiding damage to the electrically insulating tube 72; furthermore, since the corrugated tube 73 is made of metal and the metal chamber is at a high potential, in order to avoid the high voltage difference in the tube causing the transported dopant gas to dissociate, as shown in the figure, the metal chamber 70 is further connected to a voltage divider circuit 74, so that the corrugated tube 73 is electrically connected to the voltage divider node of the voltage divider circuit 74, so that the potential of the corrugated tube 73 is lower than the potential of the metal chamber 70, reducing the probability of forming a high voltage difference environment.

[0006] As can be seen from the above description, when an ion implanter uses a gas delivery device with a remotely stored bulk dopant gas source, external vibration damage and high voltage difference dissociation issues must be considered. Summary of the Invention

[0007] In view of the safety considerations of the aforementioned gas transmission device of the remote dopant gas source, the main purpose of the present invention is to provide a new gas supply system for an ion implanter.

[0008] The main technical means used to achieve the above purpose is to make the gas supply system include:

[0009] A metal chamber electrically connected to a high potential of a high voltage source, wherein a first pipe and a second pipe are disposed within the metal chamber, wherein one end of the second pipe is connected to the first pipe and the other end extends out of the metal chamber;

[0010] A plurality of electrically insulating members fixed to the bottom of the metal chamber and electrically connected to a low potential of a high voltage source;

[0011] an electrically insulating box suspended on the outer side of the metal chamber;

[0012] a rigid insulating tube disposed upright in the electrically insulating box, the rigid insulating tube having a first end and a second end, the first end being connected to one end of the second pipe extending from the outside of the metal chamber; and

[0013] a flexible tube, one end of which penetrates the electrically insulating box and is connected to the second end of the rigid insulating tube, and the other end of which is connected to a large amount of dopant gas storage chamber; wherein:

[0014] The product of the length of the electrically insulating box and the pressure of the gas in the box is greater than the maximum dissociation voltage difference between the connection point between the first end of the rigid insulating tube and the second pipeline and the connection point between the second end of the rigid insulating tube and the flexible tube;

[0015] The product of the length of the rigid insulating tube and the gas pressure of the doping gas it transports is greater than the maximum dissociation voltage difference between the connection between the first end of the rigid insulating tube and the second pipeline and the connection between the second end of the rigid insulating tube and the flexible tube.

[0016] As can be seen from the above description, the gas supply system of the present invention primarily suspends the electrical insulation box on the side of the metal chamber, maintaining a certain distance from the floor. This creates a high-voltage, insulated environment without inducing high-voltage discharges. The product of the high-pressure gas within the rigid insulating tubing and its length is designed to exceed the maximum dissociation voltage difference, ensuring that the metal chamber maintains a high-voltage operating environment. Furthermore, the electrical insulation box suspension design and the flexible tubing connecting the rigid insulating tubing absorb external vibration energy, preventing damage to the rigid insulating tubing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. 1 is a schematic diagram of the structure of the first embodiment of the gas supply system of the present invention.

[0018] Figure 2 FIG. 1 is a schematic diagram of the structure of the gas supply system according to the second embodiment of the present invention.

[0019] Figure 3 FIG. 1 is a schematic diagram of the structure of a gas supply system according to a third embodiment of the present invention.

[0020] Figure 4 A Paschen curve diagram of a dopant gas used in the gas supply system of the present invention.

[0021] Figure 5 A Paschen curve diagram of an inert gas used in the gas supply system of the present invention.

[0022] Figure 6 It is a schematic diagram of the structure of an existing gas transmission device.

[0023] Wherein, the reference numerals:

[0024] 1 floor

[0025] 10 Metal Room

[0026] 101 outside

[0027] 102 Bottom

[0028] 11 First pipeline

[0029] 12 Second pipeline

[0030] 13 Air pressure monitoring and regulating valve

[0031] 14 Multi-way gas valve

[0032] 15 gas cylinders

[0033] 20 Electrical insulation

[0034] 30 Electrical insulation box

[0035] 31 gas cylinders

[0036] 40 Rigid insulating pipe fittings

[0037] 41 First End

[0038] 42 Second End

[0039] 50 Flexible pipe fittings

[0040] 60 Third pipeline

[0041] 61 Vacuum Pump

[0042] 62 Fourth pipeline

[0043] 63 air valve

[0044] 64 Inert gas source

[0045] 70 Metal Room

[0046] 71 Bulk dopant gas storage room

[0047] 72 Electrical insulation tube

[0048] 73 corrugated tube

[0049] 74 Voltage Divider Circuit DETAILED DESCRIPTION

[0050] The present invention provides a new gas supply system for an ion implanter. The following describes the technical features of the present invention in detail with reference to several embodiments and accompanying drawings.

[0051] First see Figure 1 FIG. 1 shows a first embodiment of the gas supply system of the present invention, which includes a metal chamber 10 , a plurality of electrical insulating members 20 , an electrical insulating box 30 , a rigid insulating pipe 40 and a flexible pipe 50 .

[0052] The metal chamber 10 includes a first pipe 11 and a second pipe 12. The first pipe 11 extends from an exterior 101 of the metal chamber 10 to transport dopant gas from an ion implanter (not shown). One end of the second pipe 12 is connected to the first pipe 11, while the other end extends from the exterior 101 of the metal chamber 10. In this embodiment, the second pipe 12 is further connected in series with a pressure monitoring and regulating valve 13 to adjust the inlet pressure. For example, if the gas pressure in the second pipe 12 is 35 psi, the pressure monitoring and regulating valve 13 reduces the gas pressure in the second pipe 12 to below atmospheric pressure (<14.7 psi) before transporting it to the first pipe 11. The valve also monitors the gas pressure in the second pipe 12 at all times and transmits the monitored pressure value Sp to a remote control console.

[0053] The electrical insulating member 20 is disposed on the bottom surface 102 of the metal chamber 10 so as to maintain a certain distance d1 between the bottom surface 102 of the metal chamber 10 and the floor 1. In this embodiment, each of the electrical insulating members 20 can be an insulating barrier, and the metal chamber 10 and the insulating barriers are electrically connected to the high and low potentials of a high voltage source (e.g., 80 kilovolts; 80KV), respectively.

[0054] The electrical insulation box 30 is suspended on the outer side 101 of the metal chamber 10 , and the second pipe 12 passes through the electrical insulation box 30 . In this embodiment, the length of the electrical insulation box 30 is d3 , and the first surface 31 of the electrical insulation box 30 closest to the floor 1 does not contact the floor 1 .

[0055] The rigid insulating tube 40 is disposed upright in the electrically insulating box 30 and is substantially parallel to the outer side 101 of the metal chamber 10. The rigid insulating tube 40 has a length d2 and includes a first end 41 and a second end 42. The first end 41 is connected to the second pipe 12. In this embodiment, the rigid insulating tube 40 can be made of a highly electrically insulating hard material such as sapphire glass or ceramic, or a plasticized material (such as a polymer of vinyl, phenyl ester, or sulfide).

[0056] One end of the flexible tubing 50 penetrates the first surface 31 of the electrically insulating box 30 and connects to the second end 42 of the rigid insulating tubing 40. The other end is connected to a remote bulk dopant gas storage chamber 71. In this embodiment, the flexible tubing 50 can be made of metal, such as stainless steel or other flexible metal tubing. The flexible tubing can be inserted beneath the floor 1 without interfering with the electrically insulating components 20 or other equipment on the floor 1. The dopant gas used in conjunction with the gas supply system of the present invention can be arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphine, nitrogen trifluoride, germanium tetrahydride, or any of the aforementioned dopant gases mixed with a supplementary gas such as fluorine, carbon dioxide, hydrogen, nitrogen, or argon.

[0057] Furthermore, to prevent the rigid insulating pipe 40 from accidentally leaking dopant gas into the electrical insulation box 30 and then leaking into the factory due to rupture, the gas supply system of the present invention further includes a vacuum pump 61 and a third pipe 60 connected to the vacuum pump 61. The third pipe 60 is connected to the electrical insulation box 30. The vacuum pump 61 evacuates the electrical insulation box 30 through the third pipe 60, that is, a negative pressure environment is formed in the electrical insulation box 30, and the leaked dopant gas is promptly removed through the third pipe 60. Please refer to Figure 2As shown, the second embodiment of the gas supply system of the present invention provides another solution to the problem of inadvertent leakage of dopant gas from a ruptured rigid insulating pipe 40 into the electrical insulation box 30 and further leakage into the factory. Specifically, the electrical insulation box 30 is connected to a fourth pipeline 62, which is connected to a high-pressure inert gas source 64 via a valve 63. Once the valve 63 is opened, a high-pressure inert gas is continuously introduced into the electrical insulation box 30. The pressure of this inert gas is always greater than the pressure of the dopant gas within the rigid insulating pipe 40. In this way, if the rigid insulating pipe 40 ruptures, the dopant gas pressure within the rigid insulating pipe 40 is lower than the pressure of the inert gas within the electrical insulation box 30, allowing the inert gas to leak into the rigid insulating pipe, thereby preventing the dopant gas from leaking into the electrical insulation box and preventing leakage into the factory. The inert gas can be N2, an inert gas source, or a combination thereof. Furthermore, another feasible approach is to fill the electrical insulation box 30 with epoxy resin and cover the rigid insulating tube 40 ; therefore, when the rigid insulating tube 40 ruptures, it can be covered by the epoxy resin and the impurity gas will not leak out.

[0058] In addition, the present invention may further include a gas cylinder 15 storing dopant gas within the metal chamber 10. The gas cylinder is connected to the first pipeline 11 via a gas valve 14. The gas valve 14 may be opened as needed to allow the gas cylinder 15 to supply the dopant gas to the ion implanter via the first pipeline 11. Alternatively, the gas valve 14 may be closed to allow the second pipeline 12 to continue supplying the dopant gas to the first pipeline 11, which then supplies the dopant gas to the ion implanter.

[0059] See also Figure 3 The third embodiment of the gas supply device of the present invention is shown in FIG. Figure 1 The structure of the air supply device shown is roughly the same, but the electrical insulation box 30, the rigid insulating pipe 40 and the flexible pipe 50 are arranged above the metal chamber 10; in this way, the flexible pipe 50 passes through the upper space of the factory and will not interfere with the equipment on the factory floor 1.

[0060] As can be seen from the above description, the first end 41 of the rigid insulating tube 40 in the gas supply system of the present invention is connected to the second pipeline 12 and housed in an electrically insulating box 30 suspended within the metal chamber. When external vibrations occur, the electrically insulating box 30 and the rigid insulating tube 40 sway synchronously with the metal chamber. Furthermore, the second end 42 of the rigid insulating tube 40 is connected to the flexible tube 50, rather than to a fixed object. This allows the flexible tube 50 to absorb vibration energy within a certain earthquake intensity. The flexible tube 50 is constructed of 1 / 8-inch diameter stainless steel tubing, which is formed into a spring-like shape with fixed spacing. This spring-shaped stainless steel tubing forms a three-dimensional component, providing sufficient flexibility in the face of three-dimensional fluctuations. Therefore, during severe shaking caused by an earthquake, the spring-shaped stainless steel tubing provides sufficient space for cushioning, preventing the rigid insulating tube 40 from being fractured by the stresses of shaking.

[0061] Furthermore, the gas supply system of the present invention can also ensure that the doping gas in the rigid insulating tube 40 will not be dissociated by the high voltage during the delivery of the doping gas to the high potential metal chamber. Figure 4 The Paschen curves for five gases are shown in Figure 1. The Paschen curve function is V = f(pd). Where V is the dissociation voltage for arc or discharge between two electrodes, p is the gas pressure, and d is the electrode distance. Figure 4 As can be seen from the curve, assuming that the pressure of the transported dopant gas is a constant value, the different distances between the two electrodes can determine the dissociation voltage of the arc generated by the gas pressure. The two electrodes of the present invention refer to the first end 41 and the second end 42 of the rigid insulating tube 40. Therefore, in order to prevent the dopant gas in the rigid insulating tube 40 from being dissociated by the high voltage forming an arc, the length d2 of the rigid insulating tube 40 is determined under the premise that the pressure of the gas transported by the rigid insulating tube 40 is maintained at a constant value, and the product of the length and the gas pressure falls outside the range of the product of the gas pressure and the electrode distance corresponding to the dissociation voltage. In other words, the product of the length d2 of the rigid insulating tube 40 and the gas pressure of the dopant gas transported by it is greater than the maximum dissociation voltage difference between the connection point between the first end 41 of the rigid insulating tube 40 and the second pipeline 12 and the connection point between the second end 42 of the rigid insulating tube 40 and the flexible tube 50, so as to ensure that the dopant gas transported by the rigid insulating tube 40 will not be dissociated by the high voltage.

[0062] In addition, Paschen's law can also be used to adjust the gas pressure of the dopant gas transported by the rigid insulating tube 40 so that the product of the gas pressure and the electrode distance falls within the product range corresponding to a higher dissociation voltage. That is, the product of the length of the rigid insulating tube 40 and the pressure of the dopant gas it transports is greater than the maximum dissociation voltage difference between the first end 41 of the rigid insulating tube 40 and the second pipe 12 (metal) and the second end 42 of the rigid insulating tube 40 and the flexible tube 50 (metal). Furthermore, if Figure 2 The second embodiment of the gas supply system of the present invention is shown. By evacuating the inside of the electrical insulation box 30, the insulation of the electrical insulation box 30, which may be subjected to high voltage and become an arc discharge path, is increased, so that the dissociation voltage therein is much larger than the maximum dissociation voltage difference across the insulation distance.

[0063] Furthermore, since the electrically insulating box 30 is also suspended outside the metal chamber 10, which is electrically connected to a high potential, the possibility of arc discharge within the electrically insulating box 30 is also considered. Specifically, the product of the length d3 of the electrically insulating box 30 and the pressure of the gas within the box is greater than the dissociation voltage difference between the connection point between the first end 41 of the rigid insulating tube 40 and the second pipe 12 and the connection point between the second end 42 of the rigid insulating tube 40 and the flexible tube 50. In other words, if Figure 5 As shown, the product of the length d2 of the electrically insulating box 30 and the gas pressure therein falls outside the range of the product of the gas pressure and the electrode distance corresponding to the dissociation voltage, thereby ensuring that the inert gas (nitrogen N2) in the electrically insulating box 30 will not be dissociated by high pressure.

[0064] In summary, the electrically insulating box of the gas supply system of the present invention is suspended on an outer side 101 of the metal chamber. The rigid insulating tube 40 is disposed within the electrically insulating box, one end of which is connected to the second pipeline extending from the outer wall of the metal chamber, and the other end is connected to the flexible tube 50 extending into the electrically insulating box. Because the electrically insulating box is suspended on one side of the metal chamber, the gas within the rigid insulating tube 40 is protected from dissociation by the high pressure of the metal chamber. Furthermore, the connection between the rigid insulating tube 40 and the flexible tube 50 absorbs external vibration energy.

[0065] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims of the present invention.

Claims

1. An air supply system for an ion implanter, characterized in that: include: a metal chamber electrically connected to a high potential of a high voltage source, wherein a gas cylinder storing a dopant gas, a first pipe connected to the gas cylinder, and a second pipe are disposed within the metal chamber, wherein one end of the second pipe is connected to the first pipe through a first gas valve and the other end extends outside the metal chamber; a plurality of electrical insulating members fixed to the bottom of the metal chamber and electrically connected to a low potential of the high voltage source; an electrically insulating box; a rigid insulating pipe member uprightly disposed in the electrically insulating box, the rigid insulating pipe member having a first end and a second end, the first end being connected to one end of the second pipe extending from the outside of the metal chamber; and a flexible tube, one end of which penetrates the electrical insulation box and is connected to the second end of the rigid insulation tube, and the other end of the flexible tube is connected to a large amount of dopant gas storage chamber, The first pipeline transmits the doping gas from the gas cylinder or the large amount of doping gas storage chamber.

2. The gas supply system as claimed in claim 1, wherein the product of the length of the electrically insulating box and the gas pressure therein is greater than the maximum dissociation voltage difference between the connection between the first end of the rigid insulating tube and the second pipeline and the connection between the second end of the rigid insulating tube and the flexible tube.

3. The gas supply system as described in claim 1, wherein the product of the length of the rigid insulating pipe and the gas pressure of the doping gas it transports is greater than the maximum dissociation voltage difference between the connection between the first end of the rigid insulating pipe and the second pipeline and the connection between the second end of the rigid insulating pipe and the flexible pipe.

4. The gas supply system of claim 1 , further comprising: a third pipeline, passing through the electrical insulation box; and A vacuum pump is connected in series to the third pipe to provide a negative pressure environment for the electrical insulation box through the third pipe.

5. The gas supply system of claim 1 , further comprising: a fourth pipe, passing through the electrical insulation box; and A high-pressure inert gas source is connected to the fourth pipeline through a gas valve, and the high-pressure inert gas is continuously fed into the electrical insulation box by opening the gas valve; wherein, The gas pressure of the high-pressure inert gas source is greater than the gas pressure of the doping gas transported by the rigid insulating pipe. 6 . The gas supply system according to claim 1 , wherein the electrical insulation box is filled with epoxy resin and covers the rigid insulation pipe.

7. The gas supply system according to any one of claims 1 to 6, further comprising: An air pressure monitoring and regulating valve is connected to the second pipeline to adjust the intake pressure thereof, monitor the intake pressure and output a monitoring pressure value.

8. The gas supply system according to claim 7, wherein the pressure of the gas transported by the first pipeline is lower than the atmospheric pressure, and the pressure of the gas transported by the second pipeline is higher than the atmospheric pressure.

9. The gas supply system according to any one of claims 1 to 6, wherein the rigid insulating pipe is made of sapphire glass, ceramic or plasticized material; wherein the plasticized material is one of ethylene polymer, phenyl ester polymer and thioether polymer.

10. The gas supply system according to any one of claims 1 to 6, wherein the flexible tube is made of stainless steel.

11. The gas supply system according to any one of claims 1 to 6, wherein the doping gas is arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphine fluoride, nitrogen trifluoride, or germanium tetrahydride.

12. The gas supply system according to any one of claims 1 to 6, wherein the doping gas is a doping gas obtained by mixing one of arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphine, nitrogen trifluoride and germanium tetrahydride with one of fluorine, carbon dioxide, hydrogen, nitrogen and argon.

13. The gas supply system according to any one of claims 1 to 6, wherein the electrical insulation box is suspended outside the metal chamber near the bottom.

14. The gas supply system according to any one of claims 1 to 6, wherein the electrical insulation box is suspended outside the metal chamber near a top surface.

15. The air supply system according to claim 1, wherein the other end of the flexible tube is disposed below a floor.

16. An air supply system for an ion implanter, characterized in that: include: A metal chamber electrically connected to a high potential of a high voltage source, wherein a first pipe and a second pipe are disposed within the metal chamber, wherein one end of the second pipe is connected to the first pipe through a first air valve, and the other end of the second pipe passes through an outside of the metal chamber; a plurality of electrical insulating members fixed to the bottom of the metal chamber and electrically connected to a low potential of the high voltage source; an electrically insulating box suspended on the outer side of the metal chamber; a rigid insulating pipe member uprightly disposed in the electrically insulating box, the rigid insulating pipe member having a first end and a second end, the first end being connected to one end of the second pipe extending from the outside of the metal chamber; and a flexible tube, one end of which passes through the electrically insulating box and is connected to the second end of the rigid insulating tube, and the other end of the flexible tube is connected to a large amount of dopant gas storage chamber; The flexible tube is in the shape of a spring. When vibration occurs, the spring-shaped flexible tube can provide space buffering and the electrical insulation box and the hard insulation tube can shake synchronously with the metal chamber to prevent the hard insulation tube from being damaged by vibration. 17 . The gas supply system according to claim 16 , wherein a gas cylinder storing a doping gas is disposed inside the metal chamber, and wherein the gas cylinder is in communication with the first pipeline.

18. The gas supply system of claim 17, wherein the first pipeline conveys the dopant gas from the gas cylinder or the bulk dopant gas storage chamber.

19. The air supply system according to claim 16, wherein the other end of the flexible tube is disposed below a floor.

20. A gas supply system as described in claim 16, wherein the product of the length of the electrically insulating box and the gas pressure inside the box is greater than the maximum dissociation voltage difference between the connection between the first end of the rigid insulating tube and the second pipeline and the connection between the second end of the rigid insulating tube and the flexible tube, and wherein the product of the length of the rigid insulating tube and the gas pressure of the doped gas it transports is greater than the maximum dissociation voltage difference between the connection between the first end of the rigid insulating tube and the second pipeline and the connection between the second end of the rigid insulating tube and the flexible tube.

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