Pumping and processing device and method

Abstract

The invention relates to a pump unit (2) that is intended to be fluidically connected downstream of a process chamber (101) and upstream of a gas processing unit (3) in the direction of flow of the pu

Description

Technical field of the invention

[0001] The present invention relates to a pumping set intended to be fluidically coupled downstream of a manufacturing equipment item and upstream of a gas treatment device in the direction of flow of the pumped gases. The invention relates also to a pumping and treatment device and method. Technical background

[0002] In the semiconductor, flat screen or photovoltaic manufacturing industry, the manufacturing methods use gases which, after they have passed through primary vacuum pumps, are generally treated by gas treatment devices.

[0003] Some of these methods are said to be risky, because the gases conveyed in the vacuum lines are flammable and / or explosive. Hydrogen, silane, TEOS and hydrides will be cited by way of example.

[0004] In addition to these hazardous gaseous species, there can also be deposits of solid species reduced in the vacuum lines, that is to say not oxidized, such as silicon dust or polymers of polysilanes. These deposits can build up over time and promote the emergence of additional hazardous conditions. Indeed, some non-oxidized deposits are highly flammable. They can be ignited notably for example by virtue of a sudden pumping of strong gas flow or simply by virtue of the exposure to air of the pipelines or vacuum pumps by the operators during maintenance operations.

[0005] Some explosions can be particularly destructive because of the very great released energy. Such is the case notably with cascade explosions. A first explosion is first of all initialized by the flammable gases. This explosion places in suspension deposits of reduced solid species that are potentially present in the pipelines. These flammable solid deposits placed in suspension by the shock wave from the explosion explode in turn in a “super-explosion”.

[0006] The risk of damage to people and devices is therefore very significant.

[0007] The method currently used to address this issue is to continually dilute the pumped gases with a neutral gas, generally nitrogen. The neutral gas flow rate is determined to be able to address the most unfavorable pumping conditions with an added safety margin. This flow rate is therefore very often widely overdimensioned, which presents numerous drawbacks.

[0008] First of all, the significant input of nitrogen into the vacuum line involves additional costs linked to the gas consumption but also to the energy consumption of the vacuum pump, of the line heating devices and of the gas treatment device.

[0009] In addition, the cooling of the vacuum lines provoked by the dilution of the gases creates other drawbacks, notably because of the cost of the elements of the heating devices and the risk of failures.

[0010] This significant input of neutral gas also necessitates the overdimensioning of the gas treatment devices and of the primary pumping devices.

[0011] The dilution nitrogen also generates the formation of nitrogen oxides or “NOX”, such as NO2, in the gas treatment devices. The nitrogen oxides are toxic and constitute atmospheric pollutants which must be treated in turn.

[0012] Moreover, independently of the quantity of dilution gas injected, the operating parameters of the gas pumping and treatment devices are not always optimized to the quantity of gas that needs to be treated. Indeed, the information on the process gases injected into the process chamber is not reliably and fully accessible to be able to be exploited downstream by the gas pumping and treatment devices. It generally involves the closing of an electrical switch, making it possible only to obtain information on the introduction of gas into the chamber. In addition, this information is not always accessible on all the manufacturing equipment items. In effect, manufacturing steps in the process chamber where few gases need to be treated downstream mobilize overdimensioned dilution and treatment means and relatively significant excessive energy consumptions may ensue. Summary of the invention

[0013] One objective of the present invention is notably to reduce the energy consumption of the gas pumping and / or treatment device.

[0014] Indeed, the subject of the invention is a pumping set intended to be fluidically coupled downstream of a process chamber and upstream of a gas treatment device in the direction of flow of the pumped gases, the pumping set comprising: - a primary vacuum pump, - a Roots secondary vacuum pump, mounted in series with and upstream of the primary vacuum pump and comprising a motor, characterized in that the pumping set comprises a control unit configured to control an output parameter of the pumping set and / or of the gas treatment device as a function of an input parameter, the input parameter being the electrical power consumed by the motor of the Roots secondary vacuum pump.

[0015] The electrical power consumed by the motor of the Roots secondary vacuum pump makes it possible to estimate a quantity of gas to be treated by the gas treatment device, which makes it possible to deduce therefrom an output parameter of the pumping set and / or of the gas treatment device. By knowing, even approximately, the quantity of gas to be treated by the gas treatment device, it is possible to adapt output parameters of the pumping set or of the gas treatment device to the pumping conditions. This solution can be put in place with a pumping and treatment device that is autonomous with respect to the manufacturing equipment item, that is to say without communication with the manufacturing equipment items.

[0016] The pumping set can further comprise one or more of the features which are described hereinbelow, taken alone or in combination.

[0017] The pumping set can comprise a purging device configured to inject a purge gas into the flow path of the pumped gases between an output of the process chamber and an input of the gas treatment device.

[0018] The purging device can be configured to inject a purge gas into at least one pumping stage of the primary vacuum pump.

[0019] The purging device can comprise a controllable flow rate controller comprising a variable opening controllable valve or an on or off controllable regulation valve.

[0020] According to an exemplary embodiment, the output parameter of the pumping set is the flow rate of purge gas to be injected by the purging device. The electrical power consumed by the motor of the Roots secondary vacuum pump makes it possible to estimate a quantity of gas to be treated by the gas treatment device, which makes it possible to deduce therefrom a flow rate of purge gas to be injected. By knowing, even approximately, the quantity of gas to be treated by the gas treatment device, it is possible to adapt the flow rates of purge gas to be injected by the purging device to the pumping conditions. It is then possible to limit the purge gas consumption, which makes it possible to reduce the energy consumption of the pumping set and, at the same time, of the gas treatment device and which makes it possible to minimize, even eliminate, the formation of nitrogen oxides in the gas treatment device.

[0021] According to an exemplary embodiment, for a first state of operation of the Roots secondary vacuum pump with a first electrical power (input parameter), the output parameter, here the flow rate of purge gas to be injected, is higher than for a second state of operation of the Roots secondary vacuum pump with a second electrical power which is higher than the first electrical power.

[0022] For example, notably in cases where the purge gas is injected downstream of the Roots vacuum pump, the second state of operation corresponds to the cleaning step for which the flow rate of gas to be treated by the treatment device is lower than that of the deposition step, the already soluble cleaning gas (NF3) having less need to be treated by the gas treatment device. The first state of operation where the electrical power is lower corresponds to the deposition step.

[0023] By increasing the flow rate of purge gas injected by the purging device when the input parameter is lower, the dilution and the driving of the gases in the flow path of the gases during the deposition step are facilitated.

[0024] By reducing the flow rate of purge gas injected by the purging device when the input parameter is higher, the consumption of purge gas, and the energy consumption of the pumping set and of the gas treatment device are limited and the formation of nitrogen oxides is minimized.

[0025] The purge gas flow rate of the first state of operation is for example at least 20% higher than the purge gas flow rate of the second state of operation which can for example be zero, with the exception of a flow rate of purge gas injected at the bearings of the primary vacuum pump to protect the rolling bearings and the sealing devices situated at the ends of the primary vacuum pump.

[0026] The control unit can be configured to be able to control a plurality of flow rates of purge gas to be injected by the purging device and corresponding to a plurality of electrical power ranges consumed by the motor of the Roots secondary vacuum pump, each electrical power range corresponding to a distinct recipe that can be implemented in the process chamber.

[0027] The purging device can comprise a purge gas heating device. According to an exemplary embodiment, the output parameter of the pumping set is the electrical power of the purge gas heating device.

[0028] According to an exemplary embodiment, for a first state of operation of the Roots secondary vacuum pump with a first electrical power (input parameter), the output parameter, here the electrical power of the heating device, is higher than for a second state of operation of the Roots secondary vacuum pump with a second electrical power which is higher than the first electrical power.

[0029] By increasing the electrical power of the heating device when the input parameter is lower, the temperature of the purge gas is increased during the deposition step, which facilitates the dilution and the driving of the gases in the flow path of the gases.

[0030] By reducing the electrical power of the heating device when the input parameter is higher, excess electrical consumption of the heating device is avoided. It is thus possible to adapt the electrical consumption of the heating of the lines to the flow rates of the gases to be treated by the gas treatment device to avoid excess consumptions.

[0031] The electrical power of the heating device of the first state of operation is for example at least 20% higher than the second electrical power of the heating device of the second state of operation which can be zero.

[0032] The control unit can further be configured to be able to control a plurality of electrical powers of the heating device corresponding to a plurality of electrical power ranges consumed by the motor of the Roots secondary vacuum pump, each electrical power range corresponding to a distinct recipe that can be implemented in the process chamber. It is then possible to accurately adapt the heating of the lines to the pumping situations.

[0033] Another subject of the invention is a pumping and treatment device comprising at least one pumping set as described previously and at least one gas treatment device comprising a treatment unit and / or a washer and / or a chemisorption and / or physisorption cartridge. The treatment unit comprises for example a burner and / or an electrical system and / or a plasma generation device.

[0034] When the treatment device comprises a burner, the burner comprises, for example, an oxidizer and fuel injection device configured to inject an oxidizer and a fuel into the flow path of the pumped gases. The output parameter of the gas treatment device is for example the flow rates of oxidizer and of fuel injected by the oxidizer and fuel injection device.

[0035] For example, for a first state of operation of the Roots secondary vacuum pump with a first electrical power (input parameter), the output parameter, here the flow rates of oxidizer and of fuel injected by the oxidizer and fuel injection device, is higher than for a second state of operation of the Roots secondary vacuum pump with a second electrical power which is higher than the first electrical power.

[0036] By increasing the flow rates of oxidizer and of fuel injected into the burner when the input parameter is lower, the flame temperature of the burner is increased during the deposition step, which facilitates the treatment of the gases, notably by facilitating the transformation of the residues of the process gases into soluble species.

[0037] By reducing the flow rates of oxidizer and of fuel injected into the burner when the input parameter is higher, the flame temperature is reduced during the cleaning step, which makes it possible to save on oxidizers and fuels. It is thus possible to adapt the flow rates of oxidizer and of fuel to the flow rates of the gases to be treated by the gas treatment device to avoid excess consumptions.

[0038] The flow rates of oxidizer and of fuel of the first state of operation are for example at least 20% higher than the flow rates of oxidizer and of fuel of the second state of operation.

[0039] When the treatment unit comprises an electrical system and / or a plasma generation device, the output parameter of the gas treatment device can be the electrical power of the electrical system or of the plasma generation device.

[0040] For example, for a first state of operation of the Roots secondary vacuum pump with a first electrical power (input parameter), the output parameter, here the electrical power of the electrical system or of the plasma generation device, is higher than for a second state of operation of the Roots secondary vacuum pump with a second electrical power which is higher than the first electrical power.

[0041] By increasing the electrical power of the electrical system or of the plasma generation device when the input parameter is lower, the power of the plasma torch is increased, which facilitates the treatment of the gases, notably by facilitating the transformation of the residues of the process gases into soluble species.

[0042] By reducing the electrical power of the electrical system or of the plasma generation device when the input parameter is higher, excess electrical consumption of the electrical system or of the plasma generation device is avoided. It is thus possible to adapt the electrical consumption of the gas treatment device to the flow rates of the gases to be treated to avoid excess consumptions.

[0043] The electrical power of the electrical system or of the plasma generation device of the first state of operation is for example at least 20% higher than the electrical power of the electrical system or of the plasma generation device of the second state of operation.

[0044] The pumping and treatment device can comprise a connecting device configured to orient the gases pumped by the pumping set to the treatment unit of the gas treatment device or to a washer of the gas treatment device or to a central washer or to another gas treatment device, the output parameter of the gas treatment device being the orientation of the connecting device.

[0045] The connecting device comprises, for example, a three-way or four-way valve that is controllable by the control unit.

[0046] For example, the control unit is configured to orient the gases pumped by the pumping set to the gas treatment device for a first state of operation of the Roots secondary vacuum pump with a first electrical power and to orient the gases pumped by the pumping set to a washer of the gas treatment device or to a central washer or to another gas treatment device for a second state of operation of the Roots secondary vacuum pump with a second electrical power which is higher than the first electrical power.

[0047] The cleaning gases used during the cleaning step can be sufficiently soluble and not need to be treated beforehand by the treatment unit. The gases leaving the pumping set can then directly be conveyed to the washer or to the central washer or to another gas treatment device, by bypassing the treatment unit.

[0048] The control unit can further be configured to be able to control the orientation of the gases pumped by the pumping set according to a plurality of electrical power ranges consumed by the motor of the Roots secondary vacuum pump, each electrical power range corresponding to a distinct recipe that can be implemented in the process chamber. It is then possible to accurately adapt the orientation of the gases at the output of the pumping set to the different pumping situations.

[0049] The control unit can be configured to communicate with a central unit of a manufacturing plant, notably manufacturing semiconductor elements or photovoltaic panels or flat screens, comprising manufacturing equipment items and pumping and treatment devices fluidically coupled to the manufacturing equipment items.

[0050] Another subject of the invention is a method for pumping and treating gases by means of a pumping and treatment device as described previously, characterized in that an output parameter of the pumping set and / or of the gas treatment device is controlled as a function of an input parameter, the input parameter being the electrical power consumed by the motor of the Roots secondary vacuum pump.

[0051] The gas pumping and treatment method can be implemented in a process chamber in which recipes that alternate deposition steps with cleaning steps are implemented. Brief description of the figures

[0052] Other features and advantages of the invention will emerge from the following description, given by way of example, in a nonlimiting manner, in light of the attached drawings in which:

[0053] [Fig. 1] Figure 1 is a schematic view of a manufacturing equipment item coupled to a gas pumping and treatment device.

[0054] [Fig. 2] Figure 2 shows a schematic view of the pumping and treatment device of figure 1.

[0055] [Fig. 3] Figure 3 shows a graph of the electrical power (in Watts) consumed by the Roots secondary vacuum pump as a function of the flow of the gases pumped (in slm (1 slm corresponding to 1.69 Pa.m3 / s)) by the Roots secondary vacuum pump for all the recipes that can be implemented in the process chamber.

[0056] [Fig. 4] Figure 4 is a schematic view of a variant embodiment of a purging device of the pumping and treatment device.

[0057] In these figures, elements that are identical bear the same reference numbers. Detailed description

[0058] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Single features of different embodiments can also be combined or interchanged to provide other embodiments.

[0059] “Upstream” is understood to qualify an element which is placed before another with respect to the direction of flow of the pumped gases F1. On the other hand, “downstream” is understood to qualify an element placed after another with respect to the direction of flow of the pumped gases F1.

[0060] A primary vacuum pump is a volumetric vacuum pump, which is configured to, using two rotors, suck, transfer, then discharge a gas to be pumped at atmospheric pressure. A primary vacuum pump is configured to be able to discharge at atmospheric pressure or at a pressure greater than atmospheric pressure, notably up to 1200 mbar (120000 Pa). It is also configured to be able to be started up at atmospheric pressure. The primary vacuum pump comprises two rotors driven in rotation by at least one motor M1 of the primary vacuum pump. The primary vacuum pump is multi-staged and generally comprises between three and ten pumping stages mounted in series.

[0061] A Roots secondary vacuum pump (also called “Roots Blower”, or Roots compressor) is a volumetric vacuum pump configured to, using two Roots rotors, suck, transfer then discharge a gas to be pumped. The Roots secondary vacuum pump is mounted upstream of and in series with a primary vacuum pump. The Roots secondary vacuum pump comprises two rotors driven in rotation by a motor M2 of the Roots secondary vacuum pump. The Roots secondary vacuum pump comprises between one and three pumping stages mounted in series.

[0062] The Roots secondary vacuum pump is differentiated primarily from the primary vacuum pump by greater dimensions of pumping stages and because of the greater pumping capacities, by greater play tolerances, and by the fact that the Roots vacuum pump cannot discharge at atmospheric pressure but must be used serially mounted upstream of a primary vacuum pump.

[0063] A manufacturing plant, notably manufacturing semiconductor elements or photovoltaic panels or flat screens, comprises manufacturing equipment items 100 and pumping and treatment devices 1 fluidically coupled to the manufacturing equipment items 100.

[0064] A manufacturing equipment item 100 for a semiconductor element or a photovoltaic panel or a flatscreen comprises one or more process chambers 101 fluidically coupled to one or more pumping and treatment devices 1 (figure 1). The process chamber 101 is intended to receive one or more substrates 102 intended for the manufacturing of said elements.

[0065] Recipes 103 are implemented in the process chambers 101 of the manufacturing equipment item 100 for the control of the gases injected into the chambers 101, notably recipes 103 alternating deposition steps, for example by a precursor process gas of TEOS type, with cleaning steps, for example by a cleaning gas NF3, or recipes 103 awaiting the input or the output of the substrates 102. These recipes 103 comprise a succession of steps in which the nature, the flow rates and the pressure of the gases as well as the duration of the steps are defined, to be implemented in the process chamber 101.

[0066] The pumping and treatment device 1 comprises at least one pumping set 2 and at least one gas treatment device 3. The pumping set 2 is fluidically coupled to the process chamber 101, downstream of the process chamber 101, and is fluidically coupled to the gas treatment device 3, upstream of the gas treatment device 3 in the direction of flow of the pumped gases schematically represented by the arrows F1 in figure 1.

[0067] A same gas treatment device 3 can be coupled to several pumping sets 2.

[0068] An example of a pumping and treatment device 1 is illustrated in more detail in figure 2.

[0069] The pumping set 2 comprises a primary vacuum pump 4, a Roots secondary vacuum pump 5, mounted in series with and upstream of the primary vacuum pump 4 in the direction of flow of the pumped gases. The Roots secondary vacuum pump 5 comprises a motor M2 configured to drive two rotors of the Roots secondary vacuum pump 5 in rotation.

[0070] The pumping set 2 can also comprise at least one turbomolecular vacuum pump arranged upstream of and in series with the Roots secondary vacuum pump 5 in the direction of flow of the pumped gases F1, interposed between the process chamber 101 and the Roots secondary vacuum pump 5.

[0071] The gas treatment device 3 is configured to treat at atmospheric pressure the gases pumped by the pumping set 2.

[0072] As is known per se, the gas treatment device 3 comprises a treatment unit 6 and / or a washer 8 and / or a chemisorption and / or physisorption cartridge. The treatment unit 6 comprises for example a burner 7 configured to produce thermal reactions at high temperatures by hydrocarbon combustion and / or an electrical system configured to produce thermal reactions at high temperatures by means of heating electrical resistors and / or a plasma generation device.

[0073] According to an exemplary embodiment represented in figure 2, the gas treatment device 3 comprises a burner 7 and a washer 8 arranged in series with and downstream of the burner 7 in the direction of flow of the pumped gases F1.

[0074] The burner 7 comprises an oxidizer and fuel injection device 11 configured to inject an oxidizer, such as oxygen or air, and a fuel, such as methane, into the flow path of the pumped gases, between an output of the manufacturing equipment item 100 and the burner 7, and in particular into a combustion chamber 12 of the burner 7.

[0075] The oxidizer and fuel injection device 11 comprises, for example, a first controllable flow rate controller 13, configured to control the injection of the oxidizer and a second controllable flow rate controller 14, configured to control the injection of the fuel.

[0076] The oxidizer and the fuel injected into the combustion chamber 12 of the burner 7 produce a combustion that makes it possible to raise the pumped gases to very high temperature, which activates the formation of new chemically reactive and soluble species which can be then trapped by the washer 8.

[0077] At the output of the gas treatment device 3, the gases can be evacuated into the atmosphere or to a central washer of the manufacturing plant.

[0078] The pumping set 2 can also comprise a purging device 15 configured to inject a purge gas into the flow path of the pumped gases, between an output of the process chamber 101 and an input of the gas treatment device 3.

[0079] The purge gas is for example a neutral gas such as nitrogen or argon, even dry air.

[0080] The purging device 15 is for example configured to inject a purge gas at the input of the pumping set 2, that is to say at the input of the Roots secondary vacuum pump 5, and / or into the pumping set 2 (figure 1), for example into at least one pumping stage T1-T5 of the primary vacuum pump 4 as will be described later with reference to the variant embodiment of figure 4 and / or at the input of the gas treatment device 3.

[0081] For that, the purging device 15 comprises, for example, at least one controllable flow rate controller 16.

[0082] The flow rate controller 16 comprises, for example, a variable opening controllable valve or an on or off controllable regulation valve. The on or off controllable regulation valves are either open or closed and can switch over at high speed, that is to say change state over very short time periods, for example less than 16 msec, such as less than 10 msec. These are for example solenoid valves, such as electromagnetic or piezoelectric valves. They can therefore be controlled in opening and closure by a square wave control signal. The on or off controllable regulation valves offer the advantage of being simple, reliable, not bulky and inexpensive.

[0083] The pumping set 2 further comprises a control unit 17 configured to control an output parameter of the pumping set 2 and / or of the gas treatment device 3 as a function of an input parameter, the input parameter being the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5.

[0084] The control unit 17, such as an electronic circuit board, comprises one or more controllers or microcontrollers or processors and memory, for executing series of program instructions that make it possible to implement a gas pumping and treatment method notably for a process chamber 101 in which recipes 103 alternating deposition steps with cleaning steps are implemented.

[0085] The control unit 17 can be configured to communicate with a central unit 9 of the manufacturing plant that is remote from the pumping and treatment device 1 (figure 1). The central unit 9 is configured to communicate with at least one other local control unit of a pumping set of the manufacturing plant in order to be able to manage in particular the output parameters of a set of pumping sets and / or of gas treatment devices.

[0086] The communication between the control unit 17 and the central unit 9 can be handled via a wired or wireless link.

[0087] In particular, the control unit 17 is configured to receive the electrical power signals consumed by the motor M2 of the Roots secondary vacuum pump 5, to compare them with data stored in memory, to deduce therefrom a quantity of gas that can be treated by the gas treatment device 3 downstream. From this information and from data stored in memory, such as a look-up table, giving at least one estimation of an output parameter of the pumping set 2 and / or of the gas treatment device 3 as a function of the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5, the control unit 17 can estimate a value to be given to the output parameter or parameters.

[0088] Thus, by knowing, even approximately, the quantity of gas to be treated by the gas treatment device 3, it is possible to deduce therefrom, via the look-up table, the step of the recipe currently being carried out in the process chamber 101, and therefore the nature of the pumped gases, and adapt the output parameters of the pumping set 2 and / or of the gas treatment device 3 to the pumping conditions. This solution can be put in place with a pumping and treatment device 1 that is autonomous with respect to the manufacturing equipment item 100, that is to say without communication with the manufacturing equipment items 100.

[0089] According to an exemplary embodiment, the output parameter of the pumping set 2 is the flow rate of purge gas to be injected by the purging device 15.

[0090] The electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 makes it possible to estimate a quantity of gas to be treated by the gas treatment device 3. From this information and from data stored in memory, such as a look-up table, giving at least one estimation of the flow rate of purge gas to be injected by the purging device 15 as a function of the point where the purge gas is injected, it is possible to deduce therefrom a flow rate of purge gas to be injected.

[0091] By knowing, even approximately, the quantity of gas to be treated by the gas treatment device 3, it is possible to adapt the flow rates of purge gas to be injected by the purging device 15 to the pumping conditions. It is then possible to limit the consumption of purge gas, which makes it possible to reduce the energy consumption of the pumping set 2 and, at the same time, of the gas treatment device 3, and which makes it possible to minimize, even eliminate, the formation of nitrogen oxides in the gas treatment device 3.

[0092] According to an exemplary embodiment, for a first state of operation of the Roots secondary vacuum pump 5 with a first electrical power, the flow rate of purge gas to be injected is higher than for a second state of operation of the Roots secondary vacuum pump 5 with a second electrical power which is higher than the first electrical power.

[0093] This can be better understood by referring to the graph of figure 3 showing an example of electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 as a function of the flow of gases pumped by the Roots secondary vacuum pump 5. This graph collects together all the pumping situations that can be encountered by the pumping set 2 fluidically coupled to a process chamber 101 notably implementing recipes 103 alternating deposition steps B and cleaning steps A.

[0094] It can be seen that, during the cleaning step A, the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 is very much greater than the electrical power consumed during the deposition step B. Knowing the look-up table (or the curve of figure 3), it is possible to deduce, as a function of the electrical power consumed, whether a deposition step B or cleaning step A is taking place in the process chamber 101.

[0095] In this illustrative example, in which the purge gas is injected into the pumping stages T1-T5 of the primary vacuum pump 4, that is to say downstream of the Roots vacuum pump 5, the second state of operation in which the electrical power consumed by the motor M2 of the Roots vacuum pump 5 is the highest corresponds to the cleaning step A for which the flow rate of gas to be treated by the treatment device 3 is less than that of the deposition step B, the cleaning gas (NF3) being already soluble. The first state of operation in which the electrical power is lower corresponds to the deposition step.

[0096] The first state of operation corresponds here for example to the electrical powers consumed by the motor M2 of the Roots vacuum pump 5 that are less than 2000 W and the second state of operation corresponds for example to the electrical powers greater than or equal to 2000 W.

[0097] By increasing the flow rate of purge gas injected by the purging device 15 when the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 is lower, the dilution and the driving of the gases in the flow path of the gases during the deposition step are facilitated.

[0098] By reducing the flow rate of purge gas injected by the purging device 15 when the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 is higher, the consumption of purge gas, the energy consumption of the pumping set 2 and of the gas treatment device 3 are limited and the formation of nitrogen oxides is minimized.

[0099] The flow rate of purge gas of the first state of operation is for example at least 20% higher than the flow rate of purge gas of the second state of operation which can for example be zero, except for a flow rate of purge gas injected at the bearings of the primary vacuum pump 4 to protect the rolling bearings and the sealing devices situated at the ends of the primary vacuum pump 4.

[0100] The control unit 17 can further be configured to be able to control a plurality of flow rates of purge gas to be injected by the purging device 15 corresponding to a plurality of electrical power ranges consumed by the motor M2 of the Roots secondary vacuum pump 5, each electrical power range corresponding to a distinct recipe 103 that can be implemented in the process chamber 101. It is then possible to accurately adapt the purging flow rate to the pumping situations.

[0101] The purging device 15 can comprise a heating device 18 for the purge gas (figure 1), for heating up the purge gas for example to more than 50 °C, such as more than 500 °C.

[0102] The output parameter of the pumping set 2 that can be controlled by the control unit 17 as a function of the electrical power consumed by the motor M2 can be the electrical power of the heating device 18 to control the purge gas heating temperature.

[0103] For example, for a first state of operation of the Roots secondary vacuum pump 5 with a first electrical power, the electrical power of the heating device 18 is higher than for a second state of operation of the Roots secondary vacuum pump 5 with a second electrical power which is higher than the first electrical power.

[0104] By increasing the electrical power of the heating device 18 when the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 is lower, the temperature of the purge gas is increased during the deposition step, which facilitates the dilution and the driving of the gases in the flow path of the gases.

[0105] By reducing the electrical power of the heating device 18 when the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 is higher, excess electrical consumption of the heating device 18 is avoided. It is thus possible to adapt the electrical consumption of the heating of the lines to the flow rates of the gases to be treated by the gas treatment device 3 to avoid excess consumption.

[0106] The electrical power of the heating device 18 of the first state of operation is for example at least 20% higher than the second electrical power of the heating device 18 of the second state of operation which can be zero.

[0107] The control unit 17 can further be configured to be able to control a plurality of electrical powers of the heating device 18 corresponding to a plurality of electrical power ranges consumed by the motor M2 of the Roots secondary vacuum pump 5, each electrical power range corresponding to a distinct recipe 103 that can be implemented in the process chamber 101. It is then possible to accurately adapt the heating of the lines to the pumping situations.

[0108] In the case where the treatment unit 6 includes a burner 7, the output parameter of the gas treatment device 3 that can be controlled by the control unit 17 as a function of the electrical power consumed by the motor M2 can be the flow rates of oxidizer and of fuel injected by the oxidizer and fuel injection device 11.

[0109] For example, for a first state of operation of the Roots secondary vacuum pump 5 with a first electrical power, the flow rates of oxidizer and of fuel injected by the oxidizer and fuel injection device 11 are higher than for a second state of operation of the Roots secondary vacuum pump 5 with a second electrical power which is higher than the first electrical power.

[0110] By increasing the flow rates of oxidizer and of fuel injected into the burner 7 when the electrical power consumed by the motor M2 of the Roots vacuum pump 5 is lower, the flame temperature of the burner 7 is increased during the deposition step, which facilitates the treatment of the gases notably by facilitating the transformation of the residues of the process gases into soluble species.

[0111] By reducing the flow rates of oxidizer and of fuel injected into the burner 7 when the electrical power consumed by the motor M2 of the Roots vacuum pump 5 is higher, the flame temperature is reduced during the cleaning step, which makes it possible to save on oxidizers and fuels. It is thus possible to adapt the flow rates of oxidizer and of fuel to the flow rates of the gases to be treated by the gas treatment device 3 to avoid excess consumptions.

[0112] The flow rates of oxidizer and of fuel of the first state of operation are for example at least 20% higher than the flow rates of oxidizer and of fuel of the second state of operation.

[0113] The flow rates of oxidizer and of fuel of the second state of operation are preferably non-zero in order to always keep a flame lit, notably to more rapidly restart the deposition step which follows the cleaning step in the process chamber 101. However, and as will be seen later, the pumped gases can be diverted for the second state of operation, to bypass the treatment unit 6 and directly rejoin the washer 8 of the gas treatment device 3 or the central washer, in the cases where the recipes 103 implemented in the process chamber 101 use or generate gases and residues that are sufficiently soluble during the cleaning steps.

[0114] The control unit 17 can further be configured to be able to control a plurality of flow rates of oxidizer and of fuel injected by the oxidizer and fuel injection device 11 corresponding to a plurality of electrical power ranges consumed by the motor M2 of the Roots secondary vacuum pump 5, each electrical power range corresponding to a distinct recipe 103 that can be implemented in the process chamber 101. It is then possible to accurately adapt the oxidizer and fuel consumption to the pumping situations.

[0115] The control of the flow rate controllers 13, 14 can be done directly by the control unit 17 of the pumping set 2 or can be done by means of a control unit 19 of the gas treatment device 3 communicating with the control unit 17.

[0116] The control unit 17 and the control unit 19 can communicate with one another by wired or wireless link.

[0117] The control unit 17 can be configured to communicate with the central unit 9 of the manufacturing plant which can be configured to communicate with the local control unit 19 and with at least one other local gas treatment device control unit of the manufacturing plant in order to be able to manage the oxidizer and fuel injection flow rates of a set of gas treatment devices.

[0118] In the case where the treatment unit 6 comprises an electrical system and / or a plasma generation device, the output parameter of the gas treatment device 3 that can be controlled by the control unit 17 as a function of the electrical power consumed by the motor M2 can be the electrical power of the electrical system or of the plasma generation device.

[0119] For example, for a first state of operation of the Roots secondary vacuum pump 5 with a first electrical power, the electrical power of the electrical system or of the plasma generation device is higher than for a second state of operation of the Roots secondary vacuum pump 5 with a second electrical power which is higher than the first electrical power.

[0120] By increasing the electrical power of the electrical system or of the plasma generation device when the electrical power consumed by the motor M2 of the Roots vacuum pump 5 is lower, the power of the plasma torch is increased, which facilitates the treatment of the gases notably by facilitating the transformation of the residues of the process gases into soluble species.

[0121] By reducing the electrical power of the electrical system or of the plasma generation device when the electrical power consumed is higher, excess electrical consumption of the electrical system or of the plasma generation device is avoided. It is thus possible to adapt the electrical consumption of the gas treatment device 3 to the flow rates of the gases to be treated to avoid excess consumptions.

[0122] The electrical power of the electrical system or of the plasma generation device of the first state of operation is for example at least 20% higher than the electrical power of the electrical system or of the plasma generation device of the second state of operation.

[0123] The electrical power of the electrical system or of the plasma generation device of the second state of operation is preferably non-zero in order to conserve a minimum heating power, notably to more rapidly restart the deposition step which follows the cleaning step in the process chamber 101. However, as will be seen later, the pumped gases can be diverted for the second state of operation to bypass the treatment unit 6 of the gas treatment device 3 and directly rejoin the washer 8 of the gas treatment device 3 or a central washer, in the cases where the recipes 103 implemented in the process chamber 101 use or generate gases and residues that are sufficiently soluble during the cleaning steps.

[0124] The control unit 17 can further be configured to be able to control a plurality of electrical powers of the electrical system or of the plasma generation device corresponding to a plurality of electrical power ranges consumed by the motor M2 of the Roots secondary vacuum pump 5, each electrical power range corresponding to a distinct recipe 103 that can be implemented in the process chamber 101. It is then possible to accurately adapt the electrical consumption of the gas treatment device 3 to the pumping situations.

[0125] According to an exemplary embodiment, the pumping and treatment device 1 comprises a connecting device 20 configured to orient the gases pumped by the pumping set 2 to the treatment unit 6 of the gas treatment device 3 or to the washer 8 of the gas treatment device 3 or to a central washer or to another gas treatment device as a function of the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5, the output parameter of the gas treatment device 3 being the orientation of the connecting device 20 (figures 1 and 2).

[0126] The connecting device 20 comprises, for example, a three-way or four-way valve, that can be controlled by the control unit 17.

[0127] For example, the control unit 17 is configured to orient the gases pumped by the pumping set 2 to the treatment unit 6 for a first state of operation of the Roots secondary vacuum pump 5 with a first electrical power and to orient the gases pumped by the pumping set 2 to the washer 8 or to a central washer or to another gas treatment device for a second state of operation of the Roots secondary vacuum pump 5 with a second electrical power which is higher than the first electrical power.

[0128] The cleaning gases used during the cleaning step can be sufficiently soluble and not need to be treated beforehand by the treatment unit 6. The gases leaving the pumping set 2 can then directly be conveyed to the washer 8 or to the central washer or to another gas treatment device, by bypassing the treatment unit 6.

[0129] The control unit 17 can further be configured to be able to control the orientation of the gases pumped by the pumping set 2 according to a plurality of electrical power ranges consumed by the motor M2, each power range corresponding to a distinct recipe 103 that can be implemented in the process chamber 101. It is then possible to accurately adapt the treatment of the gases at the output of the pumping set 2 to the different pumping situations.

[0130] Figure 4 shows a more precise exemplary embodiment of the purging device 15, the purging device 15 being configured to inject a purge gas into at least one pumping stage T1-T5 of the primary vacuum pump 4.

[0131] The primary vacuum pump 4 comprises a stator (or pump body) forming at least two pumping stages T1-T5 mounted in series between a suction orifice 21 and a discharge orifice 22 and in which a gas to be pumped can circulate. In the illustrative example, the primary vacuum pump 4 comprises five pumping stages TITS. The pumping stage T1 communicating with the suction orifice 21 is the stage of lowest pressure, also called first pumping stage, and the pumping stage T5 communicating with the discharge orifice 22 is the stage of highest pressure, also called last pumping stage. The primary vacuum pump 4 further comprises two rotors extending in the compression chambers of the pumping stages T1-T5. The successive pumping stages T1-T5 are coupled in series to one another by respective inter-stage channels coupling the output of the preceding pumping stage to the input of the following stage. The rotors have for example lobes of identical profiles, for example of “Roots” type or of “claw” type, or are of screw type or of another similar volumetric vacuum pump principle. The rotors are configured to revolve synchronously in reverse directions in the pumping stages T1-T5. During rotation, the gas sucked from the input is imprisoned in the volume created by the rotors and the stator of the pumping stage T1-T5, and then is driven by the rotors to the next stage. The rotors are driven in rotation by at least one motor M1 of the primary vacuum pump 4 situated for example at one end.

[0132] The purging device 15 here comprises a distributor 23 configured to distribute a purge gas into at least one pumping stage T1-T5 of the primary vacuum pump 4 and at least one flow rate controller 16 configured to control a flow rate of purge gas in the distributor 23. 5

[0133] The distributor 23 comprises, for example, a common portion of which one input is intended to be linked to a source of purge gas and at least two branches coupled on the one hand to the common portion and on the other hand to a respective pumping stage T1-T5. The branches coupled to the first and last pumping stages T1, T5 are for example configured to emerge at bearings of the primary 10 vacuum pump 4 notably to protect the rolling bearings and the sealing devices situated at the two ends of the primary vacuum pump 4. The branches coupled to the intermediate pumping stages T2, T3, T4 are for example configured to emerge at the respective outputs of the stages.

[0134] There is for example one flow rate controller 16 arranged on each branch of 15 the distributor 23 and controllable by the control unit 17 as a function of the electrical power consumed by the motor M2 of the Roots secondary vacuum pump 5 and therefore of the quantity of gas to be treated. 29 08 25

Claims

1. A pumping and treatment device (1) comprising at least one pumping set (2) and at least one gas treatment device (3) comprising a treatment unit (6), the pumping set (2) being intended to be fluidically 5 coupled downstream of a process chamber (101), the pumping set being configured to be upstream of the gas treatment device (3) in the direction of flow of the pumped gases (F1), the pumping set (2) comprising a primary vacuum pump (4) and a Roots secondary vacuum pump (5), mounted in series with and upstream of the primary vacuum pump (4) and comprising a 10 motor (M2), characterized in that the pumping set (2) comprises a control unit (17) configured to control an output parameter of the gas treatment device (3) as a function of an input parameter, the input parameter being the electrical power consumed by the motor (M2) of the Roots secondary vacuum pump (5).15

2. The pumping and treatment device (1) as claimed in the precedingclaim, further comprising a purging device (15) configured to inject a purge gas into the flow path of the pumped gases between an output of the process chamber (101) and an input of the gas treatment device (3), characterized in that the control unit (17) is also configured to control an output parameter of 2 0 the pumping set (2), the output parameter of the pumping set (2) being the flow rate of purge gas to be injected by the purging device (15).

3. The pumping and treatment device (1) as claimed in the preceding claim, characterized in that for a first state of operation of the Roots secondary vacuum pump (5) with a first electrical power, the flow rate of 2 5 purge gas to be injected is higher than for a second state of operation of theRoots secondary vacuum pump (5) with a second electrical power which is higher than the first electrical power.

4. The pumping and treatment device (1) as claimed in one of claims 2 and 3, characterized in that the control unit (17) is configured to be able to 3 0 control a plurality of flow rates of purge gas to be injected by the purging device (15) and corresponding to a plurality of electrical power ranges consumed by the motor (M2) of the Roots secondary vacuum pump (5), each electrical power range corresponding to a distinct recipe (103) that can be implemented in the process chamber (101).29 08 25

5. The pumping and treatment device (1) as claimed in one of the preceding claims, further comprising a purging device (15) configured to inject a purge gas into the flow path of the pumped gases between an output of the process chamber (101) and an input of the gas treatment device (3), 5 characterized in that the purging device (15) comprises a heating device (18) for heating the purge gas, the control unit (17) being also configured to control an output parameter of the pumping set (2), the output parameter of the pumping set (2) being the electrical power of the heating device (18).

6. The pumping and treatment device (1) as claimed in one of the 10 preceding claims, and of which the treatment unit (6) comprises a burner (7), characterized in that the burner (7) further comprises an oxidizer and fuel injection device (11) configured to inject an oxidizer and a fuel into the flow path of the pumped gases, the output parameter of the gas treatment device (3) being the flow rates of oxidizer and of fuel injected by the oxidizer and 15 fuel injection device (11).

7. The pumping and treatment device (1) as claimed in one of the preceding claims, and of which the treatment unit (6) comprises an electrical system and / or a plasma generation device, characterized in that the output parameter of the gas treatment device (3) is the electrical power of the 2 0 electrical system or of the plasma generation device.

8. The pumping and treatment device (1) as claimed in one of the preceding claims, characterized in that it comprises a connecting device (20) configured to orient the gases pumped by the pumping set (2) to the treatment unit (6) of the gas treatment device (3) or to a washer (8) of the 2 5 gas treatment device (3) or to a central washer or to another gas treatmentdevice, the output parameter of the gas treatment device (3) being the orientation of the connecting device (20).

9. The pumping and treatment device (1) as claimed in one of the preceding claims, characterized in that the control unit (17) is configured to 3 0 communicate with a central unit (9) of a manufacturing plant, notably manufacturing semiconductor elements or photovoltaic panels or flat screens, comprising manufacturing equipment items (100) and pumping and treatment devices (1) fluidically coupled to the manufacturing equipment items (100).

10. A method for pumping and treating gases by means of a pumping and treatment device (1) as claimed in one of the preceding claims, characterized in that an output parameter of the gas treatment device (3) is controlled as a function of an input parameter, the input parameter being the5 electrical power consumed by the motor (M2) of the Roots secondary vacuum pump (5).

11. The method for pumping and treating gases as claimed in the preceding claim, characterized in that it is implemented with a process chamber (101) in which recipes (103) alternating deposition steps with 10 cleaning steps are implemented.29 08 25

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