Installation for the distribution of a precursor compound

Abstract

The invention relates to an installation (1) for the distribution of a precursor compound, comprising: an evaporation vessel (2) for containing a precursor (11) and configured to receive a carrier gas and to allow evaporation of the precursor, forming a gas mixture (12) comprising vapor of the precursor compound and carrier gas; a condensation column (3) comprising a gas mixture inlet (5) and a distribution gas outlet (8), the condensation column (3) being configured to receive, via the gas mixture inlet (5), the gas mixture (12) from the evaporation vessel (2) and to discharge the gas mixture (12) via the distribution gas outlet (8), the condensation column (3) being configured to condense at least a portion of the precursor compound vapor, forming a condensate. Abstract figure: Figure 1.

Description

Title of the invention: Installation for the distribution of a precursor compound

[0001] The present invention relates to an installation for dispensing a precursor compound and a method for dispensing such a precursor compound.

[0002] Chemical vapor deposition (or "CVD") processes are used in the electronics industry, particularly the semiconductor industry, to deposit layers of materials.

[0003] The precursor compounds, which can be solid or liquid, are generally introduced into an evaporation container.

[0004] A carrier gas enters the evaporation vessel, passes through the precursor compound and becomes saturated with the precursor compound forming a precursor compound vapor.

[0005] A gas mixture comprising the carrier gas and the precursor compound vapor is thus formed inside the evaporation container. The gas mixture leaves the evaporation container to reach, in particular, a reaction chamber of a gas deposition reactor. In the reaction chamber, a layer or film of the precursor is then formed on a substrate.

[0006] In the case of a liquid precursor, the evaporation container comprises a carrier gas inlet opening into a dip tube, the dip tube extending inside the evaporation container and being configured to extend below the surface of the liquid precursor when the evaporation container contains liquid precursor.

[0007] The carrier gas enters the evaporation vessel through the carrier gas inlet and passes into the dip tube. The carrier gas exits the dip tube allowing it to form bubbles which will become charged with precursor compound as they rise to the surface of the liquid precursor. This will entrain the gas phase of the liquid precursor and form the precursor compound vapor. The precursor compound vapor mixes with the carrier gas present in the evaporation vessel to form the gas mixture.

[0008] The concentration of precursor compound in the gas mixture is defined by the ratio between the partial pressure of the precursor and the total pressure of the gas mixture.

[0009] For most chemical vapor deposition processes, it is essential to deliver precisely metered amounts of precursor compound vapor to the reaction chamber.

[0010] A known method for providing precise quantities of precursor compound vapor relies on strict control of the precursor temperature and the total pressure of the gas mixture.

[0011] It is also known that the evaporation of the liquid precursor in the evaporation container slightly lowers the temperature of the liquid precursor and thus lowers the concentration of precursor compound in the gas mixture.

[0012] Installations are known which make it possible to compensate for slight variations in temperature caused by the energy consumption due to the evaporation of the precursor. In these installations, the regulation is based on adjusting a quantity of heat to be supplied, this quantity of heat being constant and relatively low.

[0013] Such an installation does not allow the concentration of precursor compound in the gas mixture to be kept stable when the quantity of heat to be supplied is significant and / or variable. The more abrupt the variation in the flow rate of the gas mixture, the more rapid and significant the decrease in the temperature of the liquid phase of the precursor and the more difficult it is to compensate for due to the thermal inertia of the evaporation container.

[0014] For example, highly variable flow rates of the gas mixture are required in industrial processes in which a single evaporation vessel feeds a plurality of reaction chambers and / or deposition reactors and the industrial process changes the number of reaction chambers involved and / or the number of deposition reactors involved at a given time.

[0015] One solution consists of increasing the exchange surface between a hot heat transfer fluid circulating in a double jacket of a reservoir of the evaporation container and the liquid phase of the precursor. Such a solution poses problems related to the sizing of the evaporation container and the safety of such an installation, particularly in the case of a semiconductor manufacturing plant.

[0016] There is a need to maintain the precursor compound concentration in the gas mixture stable, regardless of variations in the flow rate of the gas mixture, within a predetermined time interval. There is also a need for the precursor compound concentration in the gas mixture to be maintained stable while preserving the safety of the installation.

[0017] The present invention aims to effectively remedy these drawbacks by proposing an installation for the distribution of a precursor compound, comprising: - an evaporation container intended to contain a precursor and being configured to receive a carrier gas and to allow evaporation of the precursor by forming a gaseous mixture comprising a vapor of precursor compound and carrier gas; - a condensation column comprising a gas mixture inlet and a distribution gas outlet, the condensation column being configured to receive, via the gas mixture inlet, the gas mixture from the evaporation container and to discharge the gas mixture via the distribution gas outlet. distribution gas, in particular to enable the distribution of the gas mixture to a reaction chamber of a gas deposition reactor for the distribution of the precursor compound, the condensation column being configured to condense at least a portion of the precursor compound vapor by forming a condensate, the condensate preferably being intended to be recycled, for example intended to be poured into the evaporation container.

[0018] This makes it possible to ensure good regulation of the concentration of precursor compound in the gas mixture, while allowing greater variability in the flow rate of this gas mixture.

[0019] According to one embodiment, the evaporation container comprises a carrier gas inlet.

[0020] According to one embodiment, the evaporation container comprises a condensate inlet.

[0021] According to one embodiment, the evaporation container comprises a mixing outlet gaseous.

[0022] According to one embodiment, the evaporation container comprises a dip tube.

[0023] According to one embodiment, the evaporation container is configured to allow the gas carrier to enter the evaporation vessel via the carrier gas inlet and pass through the dip tube to bubble through the precursor forming the precursor compound vapor.

[0024] According to one embodiment, the carrier gas inlet is configured to be able to be connected to a source of a carrier gas.

[0025] According to one embodiment, the condensation column is configured so that the condensate, forming inside the condensation column, can flow, preferably by gravity, out of the condensation column, for example to enter the evaporation container.

[0026] According to one embodiment, the condensation column is configured so that the condensate, forming inside the condensation column, can flow by gravity out of the condensation column to enter the evaporation container by falling into the evaporation container by gravity.

[0027] According to one embodiment, the gas mixture inlet is fluidically connected to the gas mixture outlet.

[0028] According to one embodiment, the condensation column comprises a head and a bottom.

[0029] According to one embodiment, the condensation column extends along a vertical axis between the head and the bottom

[0030] According to one embodiment, the condensation column comprises a condensate outlet, in particular provided on the bottom.

[0031] According to one embodiment, the condensation column is configured so that the condensate exits the condensation column via the condensate outlet.

[0032] According to one embodiment, the condensate outlet is fluidically connected to the condensate inlet.

[0033] According to one embodiment, the condensation column extends along the vertical axis over a length of at least 50 cm, for example a length of at least 80 cm.

[0034] According to one embodiment, the distribution gas outlet is provided on the head.

[0035] According to one embodiment, the condensation column is configured so that the mixture gas exits the condensation column through the distribution gas outlet.

[0036] According to one embodiment, the distribution gas outlet is intended to be fluidically connected to at least one reaction chamber of a gas deposition reactor for the distribution of the precursor compound.

[0037] According to one embodiment, the condensation column comprises a first heat exchanger configured to allow the cooling of the gas mixture.

[0038] According to one embodiment, the first heat exchanger comprises at least one tube extending inside the condensation column, the tube being intended to be traversed by a cooling fluid.

[0039] According to one embodiment, the first heat exchanger is configured to allow the phase change of the gas mixture inside the condensation column.

[0040] According to one embodiment, the first heat exchanger is configured to allow clipping of the temperature of the gas mixture at the distribution gas outlet, relative to the temperature of the gas mixture at the gas mixture inlet, in particular when the temperature of the gas mixture at the gas mixture inlet varies between Tmin and Tmax, Tmax-Tmin being less than 10°C.

[0041] According to one embodiment, the first heat exchanger is configured to allow the temperature of the gas mixture at the distribution gas outlet to be at a constant temperature, in particular at the temperature Tmin, when the temperature of the gas mixture at the gas mixture inlet varies between Tmin and Tmax, Tmax-Tmin being less than 10°C.

[0042] According to one embodiment, the installation is configured so that the concentration of precursor compound in the gas mixture inside the evaporation tank is greater than or equal to the concentration of precursor compound in the gas mixture at the distribution gas outlet.

[0043] According to one embodiment, the installation is configured so that the concentration of precursor compound in the gas mixture at the gas mixture inlet is greater than or equal to the concentration of precursor compound in the gas mixture at the distribution gas outlet, for example greater by a value of at least one percentage point.

[0044] According to one embodiment, there is a volume flow rate of the gas mixture QT, in particular at the distribution gas outlet, which is equal to the sum of the volume flow rate of the carrier gas QP and the volume flow rate of the precursor compound vapor QV.

[0045] According to one embodiment, the concentration of precursor compound in the gas mixture C is such that C = PV / PT = QV / QT, PV being equal to the partial pressure of the precursor in the evaporation container and PT being the total pressure in the evaporation container.

[0046] According to one embodiment, the installation comprises a second heat exchanger to allow heat exchange between a heat transfer fluid and the precursor, the second heat exchanger being for example arranged around the outer wall of the evaporation container or inside the evaporation container.

[0047] This makes it easier to evaporate the precursor.

[0048] According to one embodiment, there is a target temperature of the precursor for which the concentration of precursor compound in the gas mixture, at the distribution gas outlet, is equal to a target concentration value, the second heat exchanger being configured to maintain the liquid precursor at an operating temperature strictly higher than the target temperature.

[0049] According to one embodiment, the evaporation container comprises a precursor inlet to allow the addition of precursor into the evaporation container 2

[0050] According to one embodiment, the evaporation container comprises a pipe for circulating the precursor inside the evaporation container before its introduction into the precursor of the evaporation container.

[0051] According to one embodiment, the pipe is configured to allow heat exchange between the precursor circulating in the pipe and the heat transfer fluid of the second heat exchanger, in particular to allow the precursor entering via the precursor inlet to be brought to a temperature close to that of the precursor which is in the evaporation container 2.

[0052] According to one embodiment, the installation comprises a pressure regulator for regulating the pressure of the gas mixture in the evaporation container.

[0053] According to one embodiment, the pressure regulator is configured to regulate the pressure of the gas entering the evaporation container.

[0054] According to one embodiment, the pressure regulator comprises an electronic pressure regulator, for example an electronic pressure regulating valve.

[0055] According to one embodiment, the installation comprises a pressure sensor for measuring the pressure of the gas mixture in the evaporation container.

[0056] This allows precise and rapid regulation of the flow rate of the gas mixture at the feed gas outlet, depending on the variation in the flow rate requirement of the gas mixture.

[0057] According to one embodiment, the pressure regulator is arranged upstream of the carrier gas inlet.

[0058] According to one embodiment, the precursor compound is an organometallic compound, comprising for example at least one of the following compounds: gallium, trimethylgallium, trichlorosilane, trimethylaluminium.

[0059] According to one embodiment, the precursor is a liquid precursor, for example at a temperature between 10°C and 50°C, at atmospheric pressure.

[0060] According to one embodiment, the carrier gas comprises at least one of: N2, H2, Ar, He.

[0061] The invention further relates to a method of dispensing a precursor compound, by means of an installation as described above, the method comprising the steps of: - have a source of carrier gas; - have at least one reaction chamber of a phase deposition reactor carbonated; - fluidly connecting the carrier gas source to the evaporation vessel to allow the carrier gas to enter the evaporation vessel; - fluidly connect the condensation column to the reaction chamber to allow distribution of the precursor compound.

[0062] The invention will be better understood upon reading the following description and examining the accompanying figure. This figure is given only as an illustration but in no way limits the invention.

[0063] [Fig-1] [Fig.l] is a schematic representation of an installation according to the invention.

[0064] As illustrated in [Fig.l], an installation 1 is shown for the distribution of a precursor compound. The installation 1 comprises an evaporation container 2 intended to contain a liquid precursor 11. In the example considered, the precursor is liquid for a temperature between approximately 10°C and 50°C at atmospheric pressure.

[0065] The evaporation container 2 is configured to receive a carrier gas and to allow evaporation of the liquid precursor 11 by forming a precursor compound vapor. The precursor compound vapor thus mixes with the carrier gas, to form a gas mixture.

[0066] The evaporation container 2 comprises a carrier gas inlet 4 for the entry of the carrier gas into the interior of the evaporation container 2.

[0067] The evaporation container 2 comprises a condensate inlet 14 and a gas mixture outlet 9.

[0068] The evaporation container 2 comprises a dip tube 10 extending inside the evaporation container 2 from the carrier gas inlet 4.

[0069] The evaporation vessel 2 is configured to allow the carrier gas to enter the evaporation vessel 2 via the carrier gas inlet 4 and pass through the dip tube 10 to bubble through the precursor 11 forming the gas mixture 12.

[0070] The installation 1 further comprises a condensation column 3 comprising a gas mixture inlet 5 and a distribution gas outlet 8.

[0071] The condensation column 3 is configured to receive, via the gas mixture inlet 5, the gas mixture 12 from the evaporation container 2 and to discharge the gas mixture 12 via the distribution gas outlet 8.

[0072] Thus, the gas mixture 12 entering through the gas mixture inlet 5, passes through the condensation column 3 to exit through the distribution gas outlet 8.

[0073] The condensation column 3 is configured to condense at least a portion of the precursor compound vapor by forming a condensate intended to be recycled, for example being intended to be discharged into the evaporation container 2.

[0074] Such a condensation column 3, by allowing a portion of the precursor compound vapor to be condensed, will cause a variation in the precursor compound concentration in the gas mixture 12 between the gas mixture inlet 5 and the distribution gas outlet 8.

[0075] The condensation column 3 is configured to allow stabilization of the temperature of the gas mixture 12 circulating in the condensation column 3, despite a variation in the flow rate of the gas mixture in the condensation column 3, the variation being within a predetermined flow rate range.

[0076] The condensation column 3 is configured so that the condensate, forming inside the condensation column 3, can flow by gravity out of the condensation column 3 and into the evaporation vessel 2 by falling into the evaporation vessel 2 by gravity.

[0077] The condensation column 3 extends along a vertical axis between a head and a bottom, a condensate outlet 6 being provided on the bottom.

[0078] The condensate outlet 6 is fluidically connected to the condensate inlet 14.

[0079] The condensation column 3 is configured so that the condensate exits the condensation column 3 via the condensate outlet 6.

[0080] The distribution gas outlet 8 provided on the head.

[0081] The condensation column 3 is configured so that the gas mixture exits the condensation column 3 via the distribution gas outlet 8.

[0082] The distribution gas outlet 8 is intended to be fluidically connected to at least one reaction chamber of a gas deposition reactor for the distribution of the precursor compound.

[0083] The gas mixture inlet 5 is fluidically connected to the mixture outlet gaseous 9.

[0084] The condensation column 3 is configured so that condensate droplets exit the condensation column 3 via the condensate outlet 6 and enter the evaporation vessel 2 via the condensate inlet 14.

[0085] The installation 1 is configured so that the condensate droplets fall by gravity into the liquid precursor IL

[0086] The condensation column 3 comprises a first heat exchanger configured to allow the cooling of the gas mixture, which allows the precursor compound vapor to be condensed.

[0087] The condensation column 3 is configured to be traversed by a cooling fluid, the cooling fluid being intended to exchange heat with the gas mixture.

[0088] The first heat exchanger comprises at least one tube extending inside the condensation column 3.

[0089] The tube is intended to be traversed by the cooling fluid.

[0090] Alternatively, the first heat exchanger comprises a plurality of tubes extending inside the condensation column 3 and intended to be traversed by a cooling fluid.

[0091] In an exemplary embodiment, the condensation column 3 comprises 37 tubes 80 cm long. In this exemplary embodiment, a precursor compound concentration remains stable at + / - 1% of a target concentration value of 12%, regardless of the flow rate of the gas mixture, the flow rate being less than or equal to 30 sim.

[0092] The first heat exchanger is configured to allow the phase change of the gas mixture inside the condensation column 3.

[0093] The installation 1 comprises a device for cooling the cooling fluid, configured to allow the temperature of the cooling fluid circulating in the condensation column 3 to be set at a predetermined temperature. It is thus possible, by adjusting the temperature of the cooling fluid circulating in the condensation column 3, to control the concentration of precursor compound in the gas mixture 12 at the distribution gas outlet 8.

[0094] The installation 1 is configured so that the concentration of precursor compound in the gas mixture 12 at the gas mixture inlet 5 is greater than or equal to the concentration of precursor compound in the gas mixture 12 at the distribution gas outlet 8.

[0095] The installation comprises a pressure sensor 13 for measuring the pressure of the gas mixture 12 in the evaporation container 2.

[0096] The installation comprises a second heat exchanger 16 for increasing or decreasing the temperature of the precursor 11. In the example shown, the second Heat exchanger 16 comprises a conduit arranged inside the evaporation container 2. The conduit is configured to allow the circulation of a heat transfer fluid, the outer wall of the conduit being in contact with the precursor 11.

[0097] Thus, the second heat exchanger 16 allows an exchange of heat between the heat transfer fluid and the precursor 11.

[0098] There is a target temperature of the liquid precursor 11 for which the concentration of precursor compound in the gas mixture 12, at the distribution gas outlet 8, is equal to a target concentration value. The second heat exchanger 16 is configured to maintain the liquid precursor 11 at an operating temperature strictly higher than the target temperature.

[0099] The evaporation vessel 2 comprises a precursor inlet 15 to allow the addition of precursor into the evaporation vessel 2. This allows a substantially constant level of precursor to be maintained within the evaporation vessel 2 over a continuous period of time. The evaporation vessel 2 comprises a pipe for circulating the precursor from its inlet through the precursor inlet 15 to the bottom of the evaporation vessel 2.

[0100] The pipe passes through the second heat exchanger 16 to allow the precursor entering via the precursor inlet 15 to be brought to a temperature close to that of the precursor which is in the evaporation container 2.

[0101] The installation 1 comprises a pressure regulator 7 for regulating the pressure of the gas entering the evaporation container 2. The pressure regulator 7 comprises an electronic pressure regulator, for example an electronic pressure regulating valve. The pressure regulator 7 is arranged upstream of the carrier gas inlet 4.

[0102] The pressure regulator 7 makes it possible to regulate the pressure of the gas mixture 12 in the evaporation container 2.

[0103] The installation 1 comprises a control unit configured to receive at least one item of information relating to the pressure of the gas mixture in the evaporation container 2 via the pressure sensor 13.

[0104] The control unit is configured to regulate the flow rate of the gas mixture based on information relating to the pressure of the gas mixture.

[0105] The control unit is configured to regulate the flow rate of the gas mixture by controlling the pressure regulator 7 to vary the flow rate of carrier gas entering the evaporation vessel 2.

[0106] The precursor compound is an organometallic compound, comprising for example at least one of the following compounds: gallium, trimethylgallium, trichlorosilane, trimethylaluminium. The carrier gas comprises at least one of: N2, H2, Ar, He.

Claims

Claims

1. Installation (1) for the distribution of a precursor compound, comprising: - an evaporation container (2) intended to contain a precursor (11) and being configured to receive a carrier gas and to allow evaporation of the precursor by forming a gas mixture (12) comprising a vapor of precursor compound and carrier gas;characterized in that the installation (1) comprises: - a condensation column (3) comprising a gas mixture inlet (5) and a distribution gas outlet (8), the condensation column (3) being configured to receive, via the gas mixture inlet (5), the gas mixture (12) coming from the evaporation container (2) and to evacuate the gas mixture (12) via the distribution gas outlet (8), in particular to allow the distribution of the gas mixture (12) to a reaction chamber of a gas deposition reactor for the distribution of the precursor compound, the condensation column (3) being configured to condense at least a portion of the precursor compound vapor by forming a condensate, the condensate preferably being intended to be recycled, for example intended to be poured into the evaporation container (2).;

2. Installation (1) according to the preceding claim, the condensation column (3) being configured so that the condensate, forming inside the condensation column (3), can flow, preferably by gravity, outside the condensation column (3), for example to enter the evaporation container (2).

3. Installation (1) according to one of the preceding claims, the condensation column (3) comprising a head and a bottom, the condensation column (3) extending along a vertical axis between the head and the bottom, the condensation column (3) comprising a condensate outlet (6) in particular arranged on the bottom, the condensation column (3) being configured so that the condensate exits the condensation column (3) via the condensate outlet (6).

4. Installation (1) according to one of the preceding claims, the condensation column (3) comprising a first heat exchanger configured to allow the cooling of the gas mixture (12).

5. Installation (1) according to one of the preceding claims, the installation (1) being configured so that the concentration of precursor compound in the gas mixture (12) at the gas mixture inlet (5) is greater than or equal to the concentration of precursor compound in the gas mixture (12) at the distribution gas outlet (8), for example greater by a value of at least one percentage point.

6. Installation (1) according to one of the preceding claims, comprising a second heat exchanger (16) to allow heat exchange between a heat transfer fluid and the precursor (11), the second heat exchanger (16) being for example arranged around the outer wall of the evaporation container (2) or inside the evaporation container (2).

7. Installation (1) according to the preceding claim, characterized in that there is a target temperature of the precursor for which the concentration of precursor compound in the gas mixture (12), at the distribution gas outlet (8), is equal to a target concentration value, the second heat exchanger (16) being configured to maintain the liquid precursor at an operating temperature strictly higher than the target temperature.

8. Installation (1) according to one of the preceding claims, the installation (1) comprising a pressure regulator (7) for regulating the pressure of the gas mixture (12) in the evaporation container (2).

9. Installation (1) according to one of the preceding claims, comprising a pressure sensor (13) for measuring the pressure of the gas mixture (12) in the evaporation container (2).

10. A method of distributing a precursor compound, by means of an installation (1) according to one of the preceding claims, the method comprising the steps of: - providing a source of carrier gas; - providing at least one reaction chamber of a gas deposition reactor; - fluidly connecting the source of carrier gas to the evaporation container (2) to allow the carrier gas to enter the evaporation container (2); fluidly connect the condensation column (3) to the reaction chamber to allow the distribution of the precursor compound.

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