Gas supply system for ion implanter

Abstract

The present invention is a gas supply system for an ion implantation machine. The gas supply system includes a metal chamber, an electrically insulating box, a rigid insulating pipe fitting, and a flexible pipe fitting. A first and a second pipeline are arranged inside the metal chamber, and its bottom is fixed on the floor through a plurality of electrically insulating parts. The electrically insulating box is suspended on an outer side of the metal chamber. The rigid insulating pipe fitting is arranged inside the electrically insulating box. One end of the rigid insulating pipe fitting is connected to the second pipeline passing through the outer wall of the metal chamber, and the other end is connected to the flexible pipe fitting penetrating into the electrically insulating box. Since the electrically insulating box is suspended on one side of the metal chamber, in order to prevent the gas in the rigid insulating pipe fitting from being electrolytically ionized under the influence of the high voltage connected to the metal chamber, this doping gas needs to be a high-pressure gas. And the connection of the rigid insulating pipe fitting to the flexible pipe fitting can absorb the external vibration energy.

Description

Technical Field

[0001] 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 gases for an ion implanter. Background Art

[0002] Ion implanters used in semiconductor device factories include multiple reaction chambers, and the types of doping gases used in each reaction chamber change with different product process recipes. These doping gases have the characteristic of being dissociated by high voltage and are also toxic to the human body. These doping gases are pre-filled into cylinders and placed in a metal chamber of the ion implanter, and are connected to the pipelines in the metal chamber. The doping gases are transported to the ion implanter through the pipelines. This metal chamber is electrically connected to a high voltage source, that is, the metal chamber is connected to the high potential of the high voltage source, and a plurality of electrical insulating members are further provided between the bottom surface of the metal chamber and the floor to prevent a high voltage difference environment from being generated in the metal chamber.

[0003] Due to the limited capacity of the gas cylinders, if the usage amounts of the doping gases in the respective reaction chambers in the ion implanter are not well controlled, the doping gases in the reaction chambers during the process will be exhausted, and the process will be forced to stop, resulting in losses. Therefore, many semiconductor device factories are currently researching and developing how to connect the pipelines of the ion implanter to a remotely stored large amount of doping gas sources to ensure gas supply. As Figure 6 shown, a gas transmission device is provided with an electrically insulating tube 72 and a metal corrugated tube 73 connected in series between a metal chamber 70 and a remotely stored large amount of doping gas storage chamber 71. The metal corrugated tube 73 has better ductility and can absorb external vibration energy to prevent the electrically insulating tube 72 from being damaged. Furthermore, since the corrugated tube 73 is made of metal and the metal chamber is at a high potential, to prevent a high voltage difference from being generated in the tube and causing the transported doping gas to dissociate, as shown in the figure, the metal chamber 70 is further connected to a voltage dividing circuit 74, and the corrugated tube 73 is electrically connected to the voltage dividing node of the voltage dividing circuit 74. In this way, the potential of the corrugated tube 73 is lower than that of the metal chamber 70, reducing the probability of forming a high voltage difference environment.

[0004] From the above description, it can be seen that when an ion implanter uses a gas transmission device for a remotely stored large amount of doping gas source, it is necessary to consider the problems of external vibration damage and high voltage difference dissociation. Summary of the Invention

[0005] In view of the safety considerations of the gas transmission device for the aforementioned remotely stored doping gas source, the main object of the present invention is to propose a new gas supply system for an ion implanter.

[0006] The main technical means used to achieve the above object is to make the gas supply system include:

[0007] A metal chamber is electrically connected to the high potential of a high-voltage source. Inside the metal chamber, a first pipeline and a second pipeline are provided. One end of the second pipeline communicates with the first pipeline, and the other end penetrates through the outer side of the metal chamber.

[0008] A plurality of electrically insulating members are fixed to the bottom of the metal chamber and are electrically connected to the low potential of a high-voltage source.

[0009] An electrically insulating box is suspended on the outer side of the metal chamber.

[0010] A rigid insulating pipe fitting is vertically arranged inside the electrically insulating box. The rigid insulating pipe fitting has a first end and a second end. The first end is connected to one end of the second pipeline that penetrates through the outer side of the metal chamber; and

[0011] A flexible pipe fitting has one end penetrating into the electrically insulating box and is connected to the second end of the rigid insulating pipe fitting. The other end of the flexible pipe fitting is used to connect to a heavily doped gas storage chamber; wherein:

[0012] 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 of the first end of the rigid insulating pipe fitting and the second pipeline and the connection of the second end of the rigid insulating pipe fitting and the flexible pipe fitting.

[0013] The product of the length of the rigid insulating pipe fitting and the gas pressure of the doped gas it conveys is greater than the maximum dissociation voltage difference between the connection of the first end of the rigid insulating pipe fitting and the second pipeline and the connection of the second end of the rigid insulating pipe fitting and the flexible pipe fitting.

[0014] As can be seen from the above description, the gas supply system of the present invention mainly suspends the electrically insulating box on one side of the metal chamber, that is, maintains a certain distance from the floor, establishing a high-voltage insulation environment without causing high-voltage discharge. Designing the product of the high-pressure gas inside the rigid insulating pipe fitting and the length of the rigid insulating pipe fitting to be greater than the maximum dissociation voltage difference can ensure that the metal chamber maintains a high-voltage operating environment; in addition, the suspension design of the electrically insulating box and the connection of the rigid insulating pipe fitting to the flexible pipe fitting can both absorb external vibration energy and prevent the rigid insulating pipe fitting from being damaged by vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the first embodiment of the gas supply system of the present invention.

[0016] Figure 2 It is a schematic structural diagram of the second embodiment of the gas supply system of the present invention.

[0017] Figure 3 It is a schematic structural diagram of the third embodiment of the gas supply system of the present invention.

[0018] Figure 4 Paschen curve of a doping gas used in the gas supply system of the present invention.

[0019] Figure 5 Paschen curve of an inert gas used in the gas supply system of the present invention.

[0020] Figure 6 Schematic structural diagram of a gas transmission device.

[0021] Wherein, reference numerals:

[0022] 1 Floor

[0023] 10 Metal chamber

[0024] 101 Outer side

[0025] 102 Bottom surface

[0026] 11 First pipeline

[0027] 12 Second pipeline

[0028] 13 Pressure monitoring and regulating valve

[0029] 14 Multi-way gas valve

[0030] 15 Gas cylinder

[0031] 20 Electrical insulator

[0032] 30 Electrical insulating box

[0033] 31 Gas cylinder

[0034] 40 Rigid insulating pipe fitting

[0035] 41 First end

[0036] 42 Second end

[0037] 50 Flexible pipe fitting

[0038] 60 Third pipeline

[0039] 61 Vacuum pump

[0040] 62 Fourth pipeline

[0041] 63 Gas valve

[0042] 64 Inert gas source

[0043] 70 Metal chamber

[0044] 71 Bulk doping gas storage chamber

[0045] 72 Electrical insulating pipe

[0046] 73 corrugated tube

[0047] 74 voltage dividing circuit Specific implementation manners

[0048] The present invention proposes a new gas supply system for an ion implanter, and the following describes the technical features of the present case in detail with multiple embodiments in conjunction with the drawings.

[0049] First, please refer to Figure 1 As shown, it is the first embodiment of the gas supply system of the present invention, which includes a metal chamber 10, a plurality of electrical insulators 20, an electrical insulating box 30, a rigid insulating pipe fitting 40, and a flexible pipe fitting 50.

[0050] The above-mentioned metal chamber 10 includes a first pipeline 11 and a second pipeline 12; wherein the first pipeline 11 penetrates out from the outer side 101 of the metal chamber 10 for conveying doping gas of an ion implanter (not shown in the figure). One end of the second pipeline 12 is connected to the first pipeline 11, and the other end penetrates out from the outer side 101 of the metal chamber 10; in this embodiment, the second pipeline 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 conveyed by the second pipeline 12 is 35 psi, then the pressure monitoring and regulating valve 13 reduces the gas pressure of the second pipeline 12 to less than atmospheric pressure (<14.7 psi) and then conveys it to the first pipeline 11, and monitors the gas pressure of the second pipeline 12 at any time, and transmits the monitored pressure value S p to a remote control console.

[0051] The electrical insulator 20 is arranged on the bottom surface 102 of the metal chamber 10 to keep 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 insulators 20 can be an insulating spacer, and the metal chamber 10 and these insulating spacers are respectively electrically connected to the high and low potentials of a high voltage source (such as 80 kilovolts; 80 KV).

[0052] The above-mentioned electrical insulating box 30 is suspended on the outer side 101 of the metal chamber 10, and the second pipeline 12 penetrates into the electrical insulating box 30; in this embodiment, the length of the electrical insulating box 30 is d3, and the first surface 31 of the electrical insulating box 30 closest to the floor 1 does not contact the floor 1.

[0053] The above-mentioned rigid insulating pipe fitting 40 is vertically arranged in the electrical insulating box 30, substantially parallel to the outer side 101 of the metal chamber 10. The length of the rigid insulating pipe fitting 40 is d2 and includes a first end 41 and a second end 42, and the first end 41 is connected to the second pipeline 12; in this embodiment, the material of the rigid insulating pipe fitting 40 can be a highly electrically insulating hard material such as sapphire glass, ceramic, or can be a plasticized material (such as polymers of ethylene, phenyl ester, thioether, etc.).

[0054] One end of the flexible pipe fitting 50 penetrates the first surface 31 of the electrical insulating box 30 and is connected to the second end 42 of the rigid insulating pipe fitting 40, and the other end is connected to a remote bulk doping gas storage chamber 71; in this embodiment, the material of the flexible pipe fitting 50 can be a metal material, such as stainless steel, or other metal flexible pipes, etc.; the flexible pipe can penetrate under the floor 1 without interfering with the electrical insulating parts 20 or other equipment on the floor 1. The doping gas used in the gas supply system of the present invention can be arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphorus trifluoride, nitrogen trifluoride, germanium tetrahydride, or any doping gas obtained by mixing any of the foregoing with a supplementary gas such as fluorine gas, carbon dioxide gas, hydrogen gas, nitrogen gas, argon gas.

[0055] Furthermore, to prevent the rigid insulating pipe fitting 40 from accidentally leaking doping gas into the electrical insulating box 30 and then leaking into the factory area due to rupture, the gas supply system of the present invention further includes a vacuum pump 61 and a third pipeline 60 connected to the vacuum pump 61. The third pipeline 60 is connected to the electrical insulating box 30. The vacuum pump 61 evacuates the inside of the electrical insulating box 30 through the third pipeline 60, that is, a negative pressure environment is formed inside the electrical insulating box 30, and the leaked doping gas is timely discharged through the third pipeline 60. Please refer to Figure 2 As shown, the second embodiment of the gas supply system of the present invention provides another method to solve the problem that the rigid insulating pipe fitting 40 accidentally leaks doping gas into the electrical insulating box 30 and then leaks into the factory area, that is, the electrical insulating box 30 is connected to a fourth pipeline 62, and the fourth pipeline 62 is connected to a high-pressure inert gas source 64 through a gas valve 63. Once the gas valve 63 is opened, a high-pressure inert gas is continuously introduced into the electrical insulating box 30, and the gas pressure of this inert gas is always greater than the doping gas pressure inside the rigid insulating pipe fitting 40. Thus, when the rigid insulating pipe fitting 40 ruptures, since the doping gas pressure inside the rigid insulating pipe fitting 40 is less than the inert gas pressure inside the electrical insulating box 30, the inert gas can leak into the rigid insulating pipe to block the leakage of the doping gas into the electrical insulating box and prevent the possibility of external leakage to the factory area. The inert gas can be N2, an inert gas source, or a combination thereof. Also, another feasible method is to fill epoxy resin inside the electrical insulating box 30 and coat the rigid insulating pipe fitting 40; therefore, when the rigid insulating pipe fitting 40 ruptures, it can be coated with epoxy resin and will not leak doping gas.

[0056] In addition, the present invention may further dispose a gas cylinder 15 storing doping gas in the above-mentioned metal chamber 10. The gas cylinder is connected to the first pipeline 11 through a gas valve 14. The gas valve 14 can be opened as needed, and the doping gas is supplied from the gas cylinder 15 to the ion implantation machine through the first pipeline 11. Of course, the gas valve 14 can also be closed, and the doping gas is still supplied from the second pipeline 12 to the first pipeline 11, and then the doping gas is supplied from the first pipeline 11 to the ion implantation machine.

[0057] Please refer to Figure 3 shown in the figure, which is the third embodiment of the gas supply device of the present invention. It is substantially the same as the Figure 1 gas supply device shown in the figure, but the electrical insulation box 30, the rigid insulation pipe fitting 40 and the flexible pipe fitting 50 are arranged above the metal chamber 10. In this way, the flexible pipe fitting 50 passes through the upper space of the factory building and will not interfere with the equipment on the factory floor 1.

[0058] As can be seen from the above description, the first end 41 of the rigid insulation pipe fitting 40 in the gas supply system of the present invention is connected to the second pipeline 12 and is accommodated in an electrical insulation box 30 suspended from the metal chamber. When an external vibration occurs due to some reason, the electrical insulation box 30 and the rigid insulation pipe fitting 40 will shake synchronously with the metal chamber. In addition, the second end 42 of the rigid insulation pipe fitting 40 is connected to the flexible pipe fitting 50 instead of being connected to a fixed object, and the vibration energy can be absorbed by the flexible pipe fitting 50 within a certain vibration amplitude. The flexible pipe fitting 50 uses a stainless steel pipe with a diameter of 1 / 8 inch, and the stainless steel pipe is formed into a spring shape at a fixed interval. The spring-shaped stainless steel pipe constitutes a three-dimensional component and can provide sufficient flexibility when changes occur in three dimensions. Therefore, when the earthquake causes severe shaking, the spring-shaped stainless steel pipe can indeed provide sufficient space buffer so that the rigid insulation pipe fitting 40 will not be stressed and broken during the shaking.

[0059] Furthermore, the gas supply system of the present invention can also ensure that the doping gas in the rigid insulation pipe fitting 40 will not be dissociated under high pressure during the transportation of the doping gas to the high-potential metal chamber. Please refer to Figure 4 shown in the figure, which is the Paschen curve of 5 gases. The Paschen curve function is V = f(pd). Among them, V is the dissociation voltage for forming an arc or discharge between two electrodes, p is the gas pressure, and d is the electrode distance. From Figure 4From the curve, it can be seen that assuming the pressure of the doped gas to be transported is a certain value, different distances between the two electrodes can determine the dissociation voltage of the arc generated by this gas pressure. And the two electrodes in the present invention refer to the first end 41 and the second end 42 of the rigid insulating pipe fitting 40. Therefore, in order to prevent the doped gas in the rigid insulating pipe fitting 40 from dissociating due to high pressure to form an arc, on the premise that the gas pressure transported in the rigid insulating pipe fitting 40 is maintained at a certain value, the length d2 of the rigid insulating pipe fitting 40 is determined, and the product of this length and the gas pressure is made to fall outside the range of the product of the gas pressure corresponding to the dissociable voltage and the electrode distance. That is, the product of the length d2 of the rigid insulating pipe fitting 40 and the gas pressure of the doped gas it transports is greater than the maximum dissociation voltage difference between the connection of the first end 41 of the rigid insulating pipe fitting 40 and the second pipeline 12 and the connection of the second end 42 of the rigid insulating pipe fitting 40 and the flexible pipe fitting 50, so as to ensure that the doped gas transported in the rigid insulating pipe fitting 40 will not dissociate due to high pressure.

[0060] In addition, the Paschen's law can also be used to cooperate with adjusting the gas pressure of the doped gas transported in the rigid insulating pipe fitting 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 pipe fitting 40 and the pressure of the doped gas it transports is greater than the maximum dissociation voltage difference between the connection of the first end 41 of the rigid insulating pipe fitting 40 and the second pipeline 12 (metal) and the connection of the second end 42 of the rigid insulating pipe fitting 40 and the flexible pipe fitting 50 (metal); furthermore, as Figure 2 shown in the second embodiment of the gas supply system of the present invention, by evacuating the electrical insulating box 30, the insulation degree of the electrical insulating box 30 that may become an arc discharge path due to high pressure is increased, so that the dissociation voltage therein is much greater than the maximum dissociation voltage difference between the two ends of the insulation distance.

[0061] In addition, since the electrical insulating box 30 is also suspended outside the metal chamber 10 that is electrically connected to the high potential, the possibility of arc discharge in the electrical insulating box 30 is also considered. That is, the product of the length d3 of the electrical insulating box 30 and the gas pressure inside the box is greater than the dissociation voltage difference between the connection of the first end 41 of the rigid insulating pipe fitting 40 and the second pipeline 12 and the connection of the second end 42 of the rigid insulating pipe fitting 40 and the flexible pipe fitting 50; that is to say, as Figure 5 shown, the product of the length d2 of the electrical insulating box 30 and the gas pressure inside the box falls outside the range of the product of the gas pressure corresponding to the dissociable voltage and the electrode distance, so as to ensure that the inert gas (nitrogen N2) in the electrical insulating box 30 will not dissociate due to high pressure.

[0062] In summary, the electrical insulation box of the gas supply system of the present invention is suspended on an outer side 101 of the metal chamber. The rigid insulating pipe fitting 40 is disposed within the electrical insulation box. One end thereof is connected to the second pipeline passing through the outer wall of the metal chamber, and the other end is connected to the flexible pipe fitting 50 penetrating into the electrical insulation box. Since the electrical insulation box is suspended on one side of the metal chamber, dissociation of the gas within the rigid insulating pipe fitting 40 due to the high pressure connected to the metal chamber is avoided, and the connection of the rigid insulating pipe fitting 40 to the flexible pipe fitting 50 can absorb external vibration energy.

[0063] Certainly, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention. However, these corresponding changes and deformations should all fall within the protection scope of the claims of the present invention.

Claims

1. A gas supply system for an ion implantation machine, characterized in that, Comprising: A metal chamber, electrically connected to the high potential of a high voltage source. Inside the metal chamber, there is a gas cylinder storing doping gas, a first pipeline connected to the gas cylinder, and a second pipeline. One end of the second pipeline communicates with the first pipeline through a first gas valve, and the other end penetrates through the outer side of the metal chamber. Multiple electrically insulating members, fixed to the bottom of the metal chamber and electrically connected to the low potential of a high voltage source. An electrically insulating box, suspended outside the metal chamber, and directly leaning against one side wall of the metal chamber. A rigid insulating pipe fitting, vertically arranged inside the electrically insulating box. The rigid insulating pipe fitting has a first end and a second end. The first end is connected to one end of the second pipeline that penetrates through the outer side of the metal chamber. And A flexible pipe fitting, one end of which penetrates into the electrically insulating box and is connected to the second end of the rigid insulating pipe fitting. The other end of the flexible pipe fitting is used to connect to a large doping gas storage chamber. 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 of the first end of the rigid insulating pipe fitting and the second pipeline and the connection of the second end of the rigid insulating pipe fitting and the flexible pipe fitting. The product of the length of the rigid insulating pipe fitting and the gas pressure of the doping gas it conveys is greater than the maximum dissociation voltage difference between the connection of the first end of the rigid insulating pipe fitting and the second pipeline and the connection of the second end of the rigid insulating pipe fitting and the flexible pipe fitting. Wherein the first pipeline conveys the doping gas from the gas cylinder or the large doping gas storage chamber.

2. The gas supply system according to claim 1, further comprising: A third pipeline, penetrating into the electrically insulating box; and A vacuum pump, connected in series to the third pipeline, providing a negative pressure environment for the electrically insulating box through the third pipeline.

3. The gas supply system according to claim 1, further comprising: A fourth pipeline, penetrating into the electrically insulating 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 input into the electrically insulating 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 conveyed by the rigid insulating pipe fitting.

4. The gas supply system according to claim 1, wherein the electrically insulating box is filled with epoxy resin and covers the rigid insulating pipe fitting.

5. The gas supply system according to any one of claims 1 to 4, further comprising: A gas pressure monitoring and regulating valve, connected to the second pipeline to adjust its inlet pressure, and monitor the inlet pressure and output the monitored pressure value.

6. The gas supply system according to claim 5, wherein the gas pressure conveyed by the first pipeline is less than atmospheric pressure, and the gas pressure conveyed by the second pipeline is greater than atmospheric pressure.

7. The gas supply system according to any one of claims 1 to 4, wherein the material of the rigid insulating pipe fitting is sapphire glass, ceramic or plasticized material; wherein the plasticized material is one of vinyl polymers, phenyl ester polymers, and sulfide polymers.

8. The gas supply system according to any one of claims 1 to 4, wherein the material of the flexible pipe fitting is stainless steel.

9. The gas supply system according to any one of claims 1 to 4, wherein the doping gas is arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphorus trifluoride, nitrogen trifluoride, germanium tetrahydride.

10. The gas supply system according to any one of claims 1 to 4, wherein the doping gas is a doped gas obtained by mixing one of arsine, phosphine, boron trifluoride, carbon monoxide, germanium tetrafluoride, silicon tetrafluoride, phosphorus trifluoride, nitrogen trifluoride, germanium tetrahydride with one of fluorine gas, carbon dioxide, hydrogen gas, nitrogen gas, argon gas.

11. The gas supply system according to any one of claims 1 to 4, wherein the electrically insulating box is suspended at a position near the bottom surface on the outer side of the metal chamber.

12. The gas supply system according to any one of claims 1 to 4, wherein the electrically insulating box is suspended at a position near the top surface on the outer side of the metal chamber.

13. The gas supply system according to claim 1, wherein the other end of the flexible pipe fitting is disposed below the floor.

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