Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
  • F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
  • F04C23/005—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids of dissimilar working principle
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
  • F04C28/02—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for several pumps connected in series or in parallel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
  • F04C28/28—Safety arrangements; Monitoring
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D19/00—Axial-flow pumps
  • F04D19/02—Multi-stage pumps
  • F04D19/04—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps
  • F04D19/046—Combinations of two or more different types of pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/005—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by changing flow path between different stages or between a plurality of compressors; Load distribution between compressors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
  • F04D27/02—Surge control
  • F04D27/0292—Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2220/00—Application
  • F04C2220/30—Use in a chemical vapor deposition [CVD] process or in a similar process
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2251/00—Material properties
  • F05C2251/04—Thermal properties
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
  • Y10T137/0324—With control of flow by a condition or characteristic of a fluid
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/8593—Systems
  • Y10T137/85978—With pump
  • Y10T137/86083—Vacuum pump

Definitions

• This invention relates to a method and/or apparatus for adjusting the operating parameters of a vacuum pump arrangement, and more particularly to a method and/or apparatus for self-adjusting the power or temperature limits of the vacuum pump arrangement based on the thermal characteristics of the gas flowing through the vacuum pump arrangement.
• a system used in semiconductor or other industrial manufacturing processes typically includes, among other things, a process tool, a vacuum pump arrangement having a booster pump and a backing pump, and an abatement device.
• the process tool typically includes a process chamber, in which a semiconductor wafer is processed into a predetermined structure.
• the vacuum pump arrangement is connected to the process tool for evacuating the process chamber to create a vacuum environment in the process chamber in order for various semiconductor processing techniques to take place.
• the gas evacuated from the process chamber by the vacuum pump arrangement might be directed to the abatement device, which destroys or decomposes harmful or toxic components of the gas before it is released to the environment.
• Hydrogen is one of the commonly used gases in processes, such as Metalorganic Chemical Vapor Deposition (MOCVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), and silicon epitaxy.
• MOCVD Metalorganic Chemical Vapor Deposition
• PECVD Plasma Enhanced Chemical Vapor Deposition
• silicon epitaxy The gases that are rich in hydrogen often exhibit very different characteristics from those including heavier gaseous components.
• the gas with a large proportion of hydrogen tends to have a high thermal conductivity, whereas the gas with a large proportion of heavy gaseous components tends to have a lower thermal conductivity.
• the temperature differential between the rotor and the stator tends to be smaller than that when the gas contains a large proportion of heavy gaseous components.
• vacuum pumps used in semiconductor manufacturing processes are often not driven as hard as they can be.
• other heavier gases are also present in various steps in many semiconductor manufacturing process cycles.
• the power limits of the vacuum pumps are often set conservatively in order to avoid pump seizure caused by a clash between the rotor and the stator. As a result, the vacuum pumps tend to be underutilized.
• predetermined safety level Due to the high thermal conductivity of hydrogen, the temperature differential between the outside and the inside of the vacuum pump tends to be smaller when the vacuum pump is pumping the hydrogen rich gas as opposed to the heavy gases. Because the internal temperature of a vacuum pump tends to be higher than the temperature on the outside, a limit set based on the thermal characteristics of the heavy gases might be too conservative for hydrogen-rich pumped gases. When the vacuum pump is pumping the hydrogen rich gas, such limit can be easily exceeded, while there is little risk for the pump to seize. This leads to nuisance tripping or a false alarm being triggered.
• the disclosure is also directed to an apparatus comprising: a process tool having a process chamber; a vacuum pump arrangement for evacuating the process chamber; and a controller configured to set operating parameters of the vacuum pump arrangement in response to information representing characteristics of a first gas flowing through the vacuum pump arrangement.
• FIG. 1 illustrates a schematic view of a system where a process chamber, a booster pump, and a backing pump are connected in series in accordance with some embodiments of the invention.
• FIG. 2 illustrates a flow chart showing a method for self-adjusting the operating parameters of the booster pump and the backing pump in accordance with some embodiments of the invention.
• FIG. 3 illustrates a graph comparing the power consumption curves of the vacuum pumps in various conditions in accordance with some embodiments of the invention.
• This disclosure is directed to a method and/or apparatus for adjusting the operating parameters of a vacuum pump arrangement in response to a signal indicative of the thermal characteristics of the gas being evacuated from a process tool upstream of the vacuum pump arrangement, or a determination of the thermal characteristics of the gas flowing through the vacuum pump arrangement based on power consumption patterns of the vacuum pump arrangement.
• the operating parameters of the vacuum pump arrangement can be adjusted in response to the signal received by the vacuum pump arrangement from a process tool that indicates the chemistry and thermal characteristics of the gas being evacuated from the process tool. Absent such signal, the thermal characteristics of the gases can be determined by analyzing the power consumption patterns, since different gases generate different power consumption patterns as they flow through the vacuum pump arrangement.
• FIG. 1 illustrates a schematic view of a system 10 where a process chamber 12 and a vacuum pump arrangement 20 are connected in series in accordance with some embodiments of the invention.
• the vacuum pump arrangement 20 draws gases out of the process chamber 12 and creates a vacuum environment in it to carry out certain processes, such as depositions, etching, ion implantation, epitaxy, etc.
• the gases can be introduced into the process chamber 12 from one or more gas sources, such as the ones designated by 14a and 14b in this figure.
• the gas sources 14a and 14b can be connected to the process chamber 12 via control valves 16a and 16b, respectively.
• the timing of introducing various gases into the process chamber can be controlled by selectively turning on or off the control valves 16a and 16b.
• the flow rates of the gases introduced from the gas sources 14a and 14b into the process chamber 12 can be controlled by adjusting the fluid conductance of the control valves 16a and 16b.
• many semiconductor processing techniques such as MOCVD, PECVD, and silicon epitaxy, often inject hydrogen rich gases into the process chamber 12 at one step, and other heavier gases at other steps.
• hydrogen rich it is understood that the hydrogen component in the gas is 50% or more in mole fraction or 7% or more in mass fraction.
• the vacuum pump arrangement 20 includes a booster pump 22 and a backing pump 24 connected in series.
• the inlet of the booster pump 22 is connected to the outlet of the process chamber 12.
• the outlet of the booster pump 22 is connected to the inlet of the backing pump 24.
• the outlet of the backing pump 24 might be connected to an abatement device (not shown in the figure) where the exhaust gases emitted from the backing pump 24 are treated in order to reduce the harmful impact the exhaust gases might have on the environment.
• Sensors can be implemented in the vacuum pump arrangement 20 to collect data of various measurements, such as the temperatures, power consumptions, pump speeds, etc., of the booster pump 22 and the backing pump 24.
• one or more sensors disposed on the foreline connecting the chamber 12 and vacuum pump arrangement 20 can be employed to determine the nature or characteristic of the gas being evacuated from the chamber 12.
• the controller 30 can be implemented in the vacuum pump arrangement 20 in the form of a control circuit, which can analyze the data to obtain power consumption patterns of the vacuum pump arrangement 20, and set the operating parameters of the vacuum pump arrangement 20 according to the power consumption patterns.
• FIG. 2 illustrates a flow chart 100 showing a method for self-adjusting the operating parameters of the vacuum pump arrangement 20 in accordance with some embodiments of the invention.
• FIG. 3 illustrates an exemplary graph comparing the power consumption curves of the booster pump 22 and the backing pump 24 in various conditions.
• the booster pump 22 and backing pump 24 are set at the hydrogen operating parameters suitable for pumping gases that are rich in hydrogen.
• the hydrogen operating parameters compared to the heavy gas operating parameters can have higher power or temperature limits.
• the hydrogen rich gas has a high thermal conductivity, which leads to a low temperature differential between the inside and outside of a vacuum pump, and therefore permits the vacuum pump to be driven harder.
• Step 104 determines whether the power consumption of the booster pump is greater than a first predetermined threshold. If the power consumption is below the first predetermined threshold, the process goes back to the beginning of step 104. If the power consumption is above the first predetermined threshold, the process proceeds to step 106. Step 106 determines whether the power consumption of the backing pump is below a second predetermined threshold. If the power consumption is above the second predetermined threshold, the process goes back to the beginning of step 104. If the power consumption is below the second predetermined threshold, the process proceeds to step 108 where the booster pump and the backing pump are set to the heavy gas operating parameters.
• the power consumption curve of the booster pump pumping hydrogen is designated by 202, whereas the power consumption curve of the booster pump pumping air is designated by 204.
• the power consumption curve of the backing pump pumping hydrogen is designated by 208, whereas the power consumption curve of the backing pump pumping air is designated by 206.
• hydrogen and air are used as the proxies of the hydrogen rich gas and heavy gas, respectively, for the purposes of explaining the process illustrated in FIG. 2.
• the x-axis represents the gas pressure at the inlet of the vacuum pump arrangement that is constructed by the serially connected booster pump and backing pump.
• the y-axis represents the power consumptions of the booster pump and the backing pump.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
• Control Of Positive-Displacement Pumps (AREA)
• Chemical Vapour Deposition (AREA)
• Non-Positive Displacement Air Blowers (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (8)

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Citations (4)

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• 2012
  • 2012-05-18 GB GB1208735.9A patent/GB2502134B/en active Active
• 2013
  • 2013-04-23 CN CN201380025957.5A patent/CN104285064B/zh active Active
  • 2013-04-23 KR KR1020147031923A patent/KR102077875B1/ko active IP Right Grant
  • 2013-04-23 EP EP13719142.5A patent/EP2850322B1/en active Active
  • 2013-04-23 JP JP2015512114A patent/JP6270067B2/ja active Active
  • 2013-04-23 US US14/391,607 patent/US20150114476A1/en not_active Abandoned
  • 2013-04-23 WO PCT/GB2013/051025 patent/WO2013171454A1/en active Application Filing
  • 2013-04-30 TW TW102115513A patent/TWI673433B/zh active

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