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
  • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
  • F04B37/06—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means
  • F04B37/08—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means by condensing or freezing, e.g. cryogenic pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
  • F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
  • F04B37/14—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use to obtain high vacuum
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B51/00—Testing machines, pumps, or pumping installations
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P95/00—Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass
• • 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
  • F04C2270/00—Control; Monitoring or safety arrangements
  • F04C2270/03—Torque
• • 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
  • F04C2270/00—Control; Monitoring or safety arrangements
  • F04C2270/80—Diagnostics

Definitions

• the present invention relates to the field of predictive and preventive maintenance of a vacuum line associated with a process chamber.
• the invention relates to monitoring the progress of the pollution phenomenon by solid products in the vacuum line (capping, seizing, etc.).
• the invention also extends to the method of monitoring this phenomenon in order to establish a diagnosis and to be able to program the preventive maintenance interventions.
• Stream lines including at least one pumping group are employed in many gas-utilizing processes requiring less than atmospheric pressure, but the gases used in these processes can be converted into byproducts.
• These by-products can be deposited in the form of a layer on the internal surfaces of the vacuum line, and in particular on the surface of the pipes, valves and other accessories, as well as on the moving and static parts of the pump, or still accumulate in dead volumes of the vacuum line. This phenomenon can lead to a loss of performance of the VIDI line and in particular of the pumping unit, or even to its failure. It is then inevitable to interrupt the progress of the process in the associated chamber to proceed with the cleaning or replacement of the relevant element of the vacuum line and in particular of the pumping unit. The costs of these unscheduled interruptions in production are considerable.
• Corrective maintenance is carried out as a function of signals emitted in particular by sensors integrated in the pumping unit.
• Two thresholds have been defined for each analogue measurement: an alarm threshold and an alarm threshold.
• the warning threshold corresponds to an abnormally high analog value, synonymous with a drift of the conditions of use of the pumping group compared to its nominal capacities. Crossing the alarm threshold means that the conditions of use of the pumping group have exceeded the nominal capacities ; and this one stops automatically. In order to minimize the importance of the intervention, the best situation would be to be able to perform corrective action as soon as the alert level is exceeded.
• Partial or total preventive maintenance operations are also carried out according to a periodicity defined as a function of the application for which the vacuum line is used. This periodicity is first evaluated theoretically and then adjusted by experience. However, the periodicity is not always well adapted to the actual state of wear of the components of the pumping unit or to the actual state of pollution of the vacuum line, which can lead to operations that are too late or too late. early.
• the difficulty lies in monitoring the warning and alarm thresholds of the analog signals of the pumping group which does not allow an elaborate diagnosis of the cause of the failure.
• Another problem is the temporal progression of the abnormal behavior of the pumping group that can cause a rapid transition from the alert threshold to the alarm threshold. In this case, it becomes almost impossible to intervene before the alarm threshold, which can lead to irreparable damage to the product being manufactured (for example a semiconductor wafer), but also to the pumping unit.
• EP-0 828 332 relates to the evaluation of the duration of use of a vacuum pump between its maintenance operations.
• the estimation of deposition of unwanted material on the rotor of the vacuum pump is done by measuring the rotational torque and / or the motor current driving the rotor.
• this measurement has the disadvantage of only looking at parameters relating to the engine.
• this measurement is polluted by the variations of flow of the pumped gas, which flux is not known. It is therefore not possible, at the time of the measurement, to distinguish whether the variation of torque or current is due to a flow variation or a pollution of the pump.
• the use of this method is therefore limited to low fluxes, so that the influence of the flux on the motor cut is negligible compared to a pollution of the pump.
• this method only evaluates the dynamic behavior of the rotating parts of the pump. It does not diagnose the cause of abnormal behavior if it is related to the malfunction of elements outside the pumping group, such as clogging of the exhaust system.
• the document US-2004 / 143,418 relates to the determination of the delay in which a failure occurs on a dry pump, the estimation of the lifetime of such a pump is carried out by statistical exploitation of the characteristic data. of the pump (current, temperature, vibrations, etc %) combined with the characteristics of the manufacturing process (gas flow, pressure, substrate temperature, etc %) . This document specifies that it is extremely difficult to predict the life of the pump without taking into account the operating conditions of the process.
• the predictive analytics system is not autonomous: î! depends on information provided by the production equipment requiring the installation of a communication line between the equipment and the monitoring server of the pumps. This line of communication is difficult to establish (confidentiality of data of the equipment manufacturer or customer, technical difficulties, etc %) and its smooth operation is not guaranteed.
• the document WO 2004/01 1 81 0 relates to a method of monitoring the state of a system including a pump, following a test phase of the pump under pre-established conditions. During the test period, signals representative of the correct operation of the system are recorded. The diagnosis of the pump is made by measuring the torque or the current consumed by the motor during the test phase, that is to say outside the production phases. The test conditions, and in particular the pumped gas flow, are pre-established in order to compare the result of the measurement with a reference recorded under the same gas flow conditions. This method is not possible to implement during periods of sustained production because for organizational reasons, it is very difficult to interrupt production in order to test the pumping unit. In addition, this method does not allow the prediction of the clogging of the pump discharge system.
• the problem is to diagnose the state of solid pollution
• a vacuum sign comprising at least one pumping unit, in order to plan the preventive maintenance operations at the most opportune moment and to anticipate a failure of the pumping unit, on any pumped flow value, without considering the conditions and parameters other than those coming from the line of vice and without interrupting His production.
• the object of the present invention is a vacuum line for pumping gases in a process chamber, comprising at least - a pumping unit comprising a pump body and a motor,
• the prediction means calculates the duration of use of the vacuum line before failure of the pumping unit, from the measurement of a parameter works! relating to the engine provided by the first means and the measurement of a functional parameter relating to the exhaust system provided by the second means.
• the means for measuring a functional parameter relating to the motor is a means for measuring at least one characteristic preferably chosen from the power or the current consumed by the motor, the torque and the vibrations. More preferably the means for measuring a parameter works! engine is a means of measuring the power consumed by the engine.
• the means for measuring a functional parameter relating to the evacuation system is a means for measuring the pressure of the gases in the evacuation system.
• the vacuum line according to the invention preferably comprises a first means for measuring the power consumed by the engine, a second means for measuring the pressure of the gases in the evacuation system, and a means for predicting the duration of the use of the vacuum line from the measurement of the power consumed by the engine and the measurement of the gas pressure in the exhaust system.
• the vacuum line may further comprise a third means for measuring a functional parameter relative to the pump body.
• the means for measuring a functional parameter relative to the pump body is a means for measuring at least one characteristic chosen preferably from the temperature of the pump body, the mechanical vibrations ef / or acoustics of the pump body, the nitrogen purge flow rate and the position of the thermal control valves.
• the vacuum line further comprises a means for predicting the duration of use of the vacuum line using the measurement of a functional parameter relative to the pump body,
• sensors can also be integrated in the pumping unit, such as for example a vibratory sensor, an acoustic sensor or an accelerometer.
• the prediction means calculates the duration of use of the vacuum line before failure of the pumping unit, from the measurement of a parameter operates! relating to the engine provided by the first means, to a measurement of a functional parameter relating to the evacuation system provided by the second means and the measurement of a functional parameter relative to the pump body provided by the third means.
• the vacuum line according to the invention is thus capable of performing a self-diagnosis, that is to say a diagnosis made without correlation with signals outside the vacuum line.
• a vacuum line according to the invention comprising a system capable of providing a diagnosis makes it possible, by providing for them, to avoid major failures when the installation of which the vacuum line is part is in a production phase active. Any failure in these circumstances can adversely affect the quality of the product being manufactured or destroy it, which generates a significant financial loss for the customer.
• the subject of the invention is also a method of monitoring a vacuum line as described above, comprising the following steps:
• the method according to the invention consists in identifying and monitoring the progression of the pollution phenomenon in a vacuum line.
• the pollution is due to the solid byproducts resulting from the process gas transformation implemented in a process chamber with which the vacuum line is associated.
• the This phenomenon is monitored by exploiting the time-out characteristic of certain signals from the measuring means, such as sensors arranged on the evacuation system and on the drive motor of the pump.
• the duration of use is obtained in particular by a statistical processing based on the temporal evolution of the amplitude of the parameters measured in order to evaluate the risk of clogging of the vacuum line.
• the parameters which are followed preferably in the context of the invention are on the one hand at least one parameter works! relative to the engine, and on the other hand at least one functional parameter relating to the evacuation system.
• the measured functional parameter relating to the motor is at least one characteristic preferably chosen from the power or the current consumed by the motor, the torque and vibrations. More preferably, the measured functional parameter relating to the engine is the power consumed.
• the measured functional parameter relating to the exhaust system is preferably the gas pressure in the exhaust system.
• the parameters whose correlation monitoring is particularly advantageous are the power consumed by the engine and the gas pressure in the evacuation system.
• the parameter works! measured relative to the motor is the power consumed by the motor
• the parameter works! gas evacuation system is the gas pressure in the exhaust system
• the duration of use of the vacuum line is calculated from the tilted time evolution of the power consumed by the engine and the gas pressure in the exhaust system.
• a functional parameter relating to the pump body can be measured.
• the functional parameter relating to the pump body is at least one characteristic preferably chosen from the temperature of the pump body, the vibrations of the pump body, the nitrogen purge flow rate and the position of the thermal control valves.
• the information on the open or closed state of the thermal control water valves may for example reveal a failure of the cooling network not visible directly by reading the temperature of the pump body.
• the monitoring and the correlation of the temporal evolution of each of the parameters chosen may further optionally include the correlation of the parameters measured with parameters outside the Vacuum Sign, such as, for example, characteristic parameters of the equipment to which the Vacuum Sign is connected.
• the invention has many advantages.
• the method according to the invention uses and exploits the data provided by the measuring means associated with the vacuum line, which can be recorded, in order to idenlify the abnormal behavior of the pumping group and to make a diagnosis in order to anticipate a problem early before exceeding the warning and alarm thresholds of analog signals.
• the method according to the invention makes it possible to identify the influence of its pollution on the state of cleanliness of the gas evacuation system.
• the method according to the invention thus detects the pollution of elements external to the pumping unit such as the evacuation pipe of the pumped gases, a trap or a valve in line on this pipe, or the connection of this pipe to the treatment system.
• the method according to the invention makes it possible to privilege predictive maintenance, it is to maintain the vacuum line only when there is a real need. This avoids costly and sometimes unjustified preventive maintenance operations.
• the diagnosis is early, which minimizes the damage associated with the wear of the components and thus further reduces the cost of maintenance.
• the present invention can be used in a diagnostic logic application that can be integrated into the supervision network of the pumping group in situ, to the pumping unit itself, or to a remote system. software application to perform a self-diagnosis of the vacuum line, ie without correlation with signals outside the pumping group.
• FIG. 1 schematically represents a vacuum line according to the invention
• FIG. 2 shows the repetitive variation of the power consumed by the engine and the pressure of the gases in the exhaust system that is Siée to the variations of the gas flow admitted into the pumping unit during the treatment; the power consumed by the engine M in watts (W) and the gas pressure G in millibars (m bar) are given on the ordinate, and on the abscissa the time T without units;
• FIG. 3 shows a point variation of the power consumed by the engine and the gas pressure which is caused by the pumping of gases from the atmospheric pressure;
• IQ power M in watts is given in ordinate left and pressure G in millibars in ordinate right, and in abscissa time T without units;
• FIG. 4 shows the gradual decrease in the power consumed by the engine after starting; the power M in watts and the pressure G in millibars are given on the ordinate, and on the abscissa the time T without units;
• FIG. 5 shows a progressive increase of the power consumed by the engine and of the gas pressure which is caused by the clogging of the evacuation pipe, the power M in watts and the pressure G in millibars are given on the ordinate, and in abscissa the time T without units, - figure ⁇ shows the random variation of the power consumed by the engine presaging an imminent biocage of the dynamic parts of the pumping group, its power M in watts is given in ordinate, and in abscissa the time T without units,
• the installation shown in FIG. 1 comprises a process chamber 1 intended for the treatment of a substrate. It may be, for example, processes for deposition, etching, ion implantation or heat treatment used in the manufacture of microelectronic devices on silicon wafers. it may also be micro-machining of semiconductor substrates for the production of electromechanical microsystem components (MEMS) or electro-optomechanical microsystems (MOEMS).
• Process chamber 1 is connected by a pipe 2 provided with valves 3a, 3b, 3c to a pump body 4 driven by a motor 5.
• the pump body 4 is connected to a discharge pipe 6 by a silencer 7.
• the pipe may be equipped with a trap 8 for capturing the solid by-products of the reaction, when the gaseous by-products of the process used can not be discharged into the general evacuation 9, the exhaust gases are carried out by the intermediate of a treatment plant 10 through the valves 1 1 a and 1 1 b.
• Process gases can be converted into solid by-products and accumulate in process chamber 1, in line 2 connecting chamber 1 to pump body A, in pump body 4, in silencer 7, in the pipe 6 which leads to the gas treatment plant 10, in the trap 8 and in the valves 11a, 11b.
• the variation of the value of a functional parameter of the pumping group, related to a normal operation can be for example:
• FIG. 2 illustrates the variation of the pressure of the gases G (curve 20) in the evacuation system and the power consumed by the motor M (curve 21) which is due to the variations gas flow to the pumping group when production operations are in progress, or
• Figure 3 illustrates the simultaneous increase in the simultaneous pressure of G gases (curve 30) and the power consumed by the motor M
• curve 31 which is pumping a volume of gas at atmospheric pressure
• Figure 4 illustrates the progressive decrease in the power consumed by the motor M '(curve 41) of the primary pump of the group after start, which is due to the heating of the pumping unit and the progressive evacuation of the solid residues accumulated in the pump body during the stopping phase.
• Curve 40 represents the power consumed by the motor M of the secondary pump of the group.
• the variation of the value of a parameter related to an abnormal operation can be for example:
• Figure 5 illustrates the gradual increase in the power consumed by the motor M (curve 50) and the gas pressure G (curve 51) in the evacuation system, which reveals a clogging the discharge pipe of the pumped gases, or
• the curve 60 of Figure 6 illustrates power peaks consumed by the motor M successive which are the sign of an impending blocking of dynamic parts.
• the invention makes it possible in particular to detect the following phenomena before they induce an irreversible failure of the pumping unit, in particular a clogging of the silencer, the trap, the pipe or the valves of the gas evacuation system, and in some conditions internal clogging of the pumping group by solid byproducts resulting from the transformation of the pumped gases.
• the clogging is identified by monitoring the evolution over time of the power consumed by the engine M and the pressure of the gases G.
• a mathematical algorithm has been determined to measure this evolution and to calculate the time remaining before reaching predefined critical analog thresholds.

Landscapes

• 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)
• Drying Of Semiconductors (AREA)
• Control Of Positive-Displacement Air Blowers (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

Family

ID=36046932

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (28)

Family Cites Families (15)

• 2005
  • 2005-07-04 FR FR0552027A patent/FR2887938A1/fr not_active Withdrawn
• 2006
  • 2006-06-27 EP EP06116150A patent/EP1754888B1/fr not_active Revoked
  • 2006-06-27 AT AT06116150T patent/ATE428051T1/de not_active IP Right Cessation
  • 2006-06-27 DE DE602006006122T patent/DE602006006122D1/de active Active
  • 2006-06-30 US US11/477,361 patent/US7543492B2/en not_active Expired - Fee Related
  • 2006-07-04 JP JP2008518942A patent/JP5053269B2/ja not_active Expired - Fee Related
  • 2006-07-04 KR KR1020087002832A patent/KR101319250B1/ko not_active Expired - Fee Related
  • 2006-07-04 CN CN2006800241425A patent/CN101213371B/zh not_active Expired - Fee Related
  • 2006-07-04 WO PCT/FR2006/050673 patent/WO2007003862A2/fr not_active Ceased

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