DE202017003314U1 - Device for providing trimethylaluminum - Google Patents

Abstract

Apparatus for providing trimethylaluminum, TMA for short, comprising: a housing; a plurality of conduits for supplying gas to at least one process module in the housing; a tempering unit for controlling the temperature of the interior of the housing and the accommodated components to a predetermined internal temperature; a TMA vaporizer vessel in the housing having an outlet conduit and an inlet conduit, the outlet conduit extending from an upper portion of the TMA vaporizer vessel into the housing and connected to at least one process module via a metering unit in the housing and the inlet conduit at least partially extends through the housing and into the TMA vaporizer vessel and is connectable to a supply line located outside the housing, the area of the inlet line located inside the housing having a predetermined volume, and a control unit configured to intermittently fill TMA into the TMA Vaporizer vessel in which TMA is alternately introduced into the TMA vaporizer vessel via the inlet line during an intake cycle and is maintained in the intake line during a hold cycle TMA but not introduced into the TMA vaporizer vessel, during each intake cycle a TMA volume is introduced into the TMA evaporator vessel that is less than or equal to the predetermined volume.

Description

The present invention relates to a device for providing trimethylaluminum, TMA for short.

TMA is used for different processes, including for the processing of substrates, in particular semiconductor substrates. TMA is highly corrosive and ignites spontaneously in the air and reacts explosively with water. Therefore, when dealing with TMA have high security requirements. Due to local regulations, for example in Asia, the maximum TMA storage quantities per area are limited in the vicinity of process equipment requiring operator access.

In particular, in the processing of semiconductor substrates TMA must be accurately metered for processing, here often systems are used in which a carrier gas is passed through liquid TMA to accommodate TMA. Also, an evaporator system is known in which a larger amount of liquid TMA is also maintained at a predetermined temperature to vaporize TMA to then supply the thus evaporated TMA to a subsequent process, where even a temperature of 25 ° C is sufficient to provide a vapor pressure of about 2670 Pa. Typically, such evaporators are maintained at a temperature of 40 ° C, resulting in a vapor pressure of about 4000 Pa results. Such vaporized TMA can be well dosed provided for processing of semiconductor substrates with known vapor pressure.

Due to possible limitations of the maximum amount of TMA vorzuhaltenden now the problem arises that a corresponding evaporator vessel must be replaced or replenished more frequently. However, any system opening requires longer downtime, during which time TMA can not process. In addition, there is a risk that air enters the system, which is a security risk.

Therefore, a closed refill system in which an evaporator vessel does not need to be opened is contemplated, and in which the size-limited evaporator vessel can be replenished via a remote TMA storage vessel not subject to size limitation.

Although a refill system can reduce problems with the opening of the vaporizer vessel and the resulting downtime, in an evaporator system of the type described above in which a predetermined vapor pressure produces a given vapor pressure, these can produce variations in vapor pressure, which in turn reduces the accuracy of the TMA Affect dosage. Such fluctuations arise in particular in that the temperature of the tracked TMA differs from the temperature of the TMA in the evaporator vessel. The greater the temperature difference and the larger the tracked TMA amount, the greater are corresponding fluctuations.

An example of a refill system, which should be suitable for TMA among others, is from the WO 2006 059 187 A1 known. In this system, a special heater is provided between a remote reservoir and a local reservoir.

The invention is based on the object to provide a device for providing TMA that has a simple structure.

According to the invention, a device for providing trimethylaluminum, TMA for short, is provided according to claim 1. In particular, the apparatus for providing trimethylaluminum comprises: a housing, a plurality of conduits for supplying gas to at least one process module in the housing, a temperature control unit for controlling the interior of the housing and the accommodated components to a predetermined internal temperature, a TMA evaporator vessel in the housing having an outlet conduit and an inlet conduit, the outlet conduit extending from an upper portion of the TMA vaporizer vessel into the housing and connected to at least one process module via a metering unit in the housing and the inlet conduit at least partially through the housing and extends in a lower region of the TMA evaporator vessel and is connectable to a lying outside the housing supply line, wherein the lying within the housing portion of the inlet line has a predetermined volume, and a control unit config for intermittently introducing TMA into the TMA vaporizer vessel, where TMA is alternately introduced into the TMA vaporizer vessel via the inlet line during an intake cycle, and is kept in the intake line during a hold cycle TMA but not introduced into the TMA vaporizer vessel, wherein during each intake cycle, a TMA volume is introduced into the TMA evaporator vessel that is less than or equal to the predetermined volume.

Such a device allows TMA to be introduced into the TMA vaporizer vessel such that only as much TMA is introduced during each intake cycle as in the interior of the housing during the hold cycle Inlet line was kept, and this can be tempered to the predetermined internal temperature in the housing. Preferably, the control unit is configured to select the length of the holding cycle such that TMA in the portion of the inlet duct located in the housing substantially assumes the predetermined internal temperature, with substantially deviations of at most 5 ° C, preferably 3 ° and more preferably should not exceed 1 °.

According to one embodiment, the device further comprises a level monitoring unit for the TMA evaporator vessel, which is suitable to determine the level inside the TMA evaporator vessel via a sensor and wherein the control unit is suitable, the inlet and holding cycles at least partially based on the determined level to control. As a result, the level in the TMA evaporator vessel can be controlled.

In one embodiment, the control unit is configured to receive consumption data via the dosing unit and to control the intake and hold cycles at least partially based on the consumption data.

Preferably, the predetermined volume is sized to be greater than or equal to a maximum expected TMA consumption for a predetermined period of time, such as one hour, to allow sufficient time for temperature control of the TMA in the inlet conduit to the predetermined internal temperature.

According to one embodiment, the upper region of the TMA evaporator vessel is in the upper half, preferably in the upper third of the TMA evaporator vessel and / or the lower region of the TMA evaporator vessel in the lower half, preferably in the lower third of the TMA evaporator vessel Level of liquid TMA in the TMA evaporator vessel is usually maintained at a level between a lower end of the inlet conduit and a lower end of the outlet conduit.

Preferably, the predetermined volume is in the range of 10-100 ml, preferably in the range of 20 to 30 ml, and the volume of the TMA evaporator vessel in the range of 1 and 5 liters, preferably in the range of 1.5 and 3 liters. Thus, the predetermined volume is significantly smaller compared to the volume of the TMA vaporizer vessel, and in particular also compared to an average retained TMA liquid volume in the TMA vaporizer vessel, so that an effect of a TMA liquid filled in during a filling cycle is reduced to the temperature of the TMA vaporizer vessel. Evaporator vessel befindliches TMA liquid is low. In particular, the predetermined volume is at least a factor of 50, preferably a factor of 100, smaller than the volume of the TMA vaporizer vessel, and preferably a factor of at least 30-50 smaller than the volume of the average TMA fluid amount.

The invention will be explained in more detail with reference to the drawings. In the drawings shows:

1 a schematic cross-sectional view through an apparatus for providing trimethylaluminum;

2 a schematic sectional view through a TMA evaporator vessel of the device according to 1 ,

Location information used in the following description refers primarily to the illustration in the drawings and therefore should not be taken as limiting. You can also refer to a preferred final arrangement.

1 shows a schematic cross-sectional view of a device 1 for providing trimethylaluminum, TMA for short. The device 1 has a housing 3 , a variety of wires 5 . 6 in the case 3 for the gas supply at least one (not shown) process module, a temperature control unit 8th for tempering the interior of the housing 3 and the absorbed components to a predetermined internal temperature, a TMA evaporator vessel 10 in the case 3 that is an outlet pipe 6 and an inlet pipe 12 and at least one metering unit 14 on.

The housing 3 may be a housing known in the art, commonly referred to as a gas cabinet, which typically houses a plurality of gas supply ports, internal gas lines and gas exhaust ports, and a control or regulating unit that controls gas flows between the gas supply ports and the gas exhaust ports.

The temperature control unit 8th may be of any suitable type which is suitable for bringing and maintaining the temperature inside the housing and thus also the components therein to a predetermined temperature. In particular, the temperature control unit should 8th be designed so that it can set a predetermined temperature in the range of 35 ° C to 50 ° C, in particular in the range of 38 ° C to 45 ° C. A uniform internal temperature or a temperature slightly rising in the direction of the process units in the housing has the advantage that a condensation of gases in Gas-carrying parts can be avoided, if the temperature is selected accordingly. Also, more uniform gas pressures can be maintained in the gas-carrying parts. Within the housing, a temperature gradient of a few ° C running from bottom to top, wherein the area lying below are cooler, preferably less than 5 ° C can be set.

Gas-carrying parts are in 1 for example, the lines 5 and 6 as well as the dosing unit, via which the lines 5 with the line 6 keep in touch. In the illustration are three lines 5 provided, for example, each form a supply line for a process unit. The lines are via the dosing unit 14 with gas, especially TMA in gaseous form. For this purpose, the dosing unit 14 over the line 6 supplied with TMA in gaseous form. The administration 6 in turn provides an outlet line of a TMA vaporizer vessel 10 as is usual.

While in the past TMA vaporizer vessels with a sufficient volume have been used for weeks or even longer periods of time, efforts are now being made to substantially limit the volume of TMA vaporizer vessels. This in 1 illustrated TMA evaporator vessel 10 For example, it has a volume of 1 to 5 liters, with a volume of 2 to 3 liters being preferred. Here is the volume of the TMA evaporator vessel 10 of course greater than the volume of TMA liquid held in the TMA vaporizer vessel. For example, in operation, approximately half of the volume will be filled by TMA fluid, while approximately the other half will be filled by TMA gas. Such a situation is exemplary in 2 shown. Of course, the consumption of TMA results in fluctuations in the respective volumes during operation. For example, the average retained volume is reduced to such an extent that in normal operation it only lasts for 1 to 2 days instead of weeks.

The temperature of the TMA evaporator vessel 10 and the TMA contained therein during operation by the temperature control unit 8th substantially constant at the predetermined internal temperature of the housing 3 held. As a result, above the TMA liquid, a certain vapor pressure is generated, such as a vapor pressure of about 4,000 Pa at a temperature of 40 ° C. Such a predetermined vapor pressure allows a good dosage of TMA gas via the metering unit 14 and the wires 5 corresponding process units.

In order to be able to process interruption-free over longer periods of time, such as weeks or even longer, despite a reduced volume of the TMA evaporator vessel, the device has 1 The administration 12 on, as shown essentially inside the case 3 runs. The administration 12 is about a connection 16 with an external line 17 connected to an external TMA source that is, for example, in a fire protection area and thus not subject to the volume limitations in the process area. Such a TMA source may provide TMA fluid for extended periods of time, such as weeks or longer.

But it is over the line 12 not continuous TMA in liquid form into the TMA vaporizer vessel 10 passed but intermittently. This is a control unit 18 provided, which is schematically in 1 on the line 12 is shown. The control unit 18 For example, it may have a volumetric flow regulator or even simple valves. In particular, the control unit 18 configured to intermittently introduce TMA into the TMA vaporizer vessel, wherein liquid TMA alternately over the inlet line during an intake cycle 12 is introduced into the TMA evaporator vessel, and during a hold cycle TMA in the inlet line 12 held but not introduced into the TMA evaporator vessel. Here is the control unit 18 specifically configured to introduce a TMA volume into the TMA vaporizer vessel that is less than or equal to a predetermined volume during each intake cycle. In this case, the predetermined volume corresponds to the volume of the part of the line 12 inside the case 3 is and thus usually tempered during operation to the internal temperature.

Thus, the liquid TMA introduced during an intake cycle into the TMA vaporizer vessel 10 in each case essentially the same temperature as the TMA in the TMA evaporator vessel 10 , As a result, temperature fluctuations in the TMA evaporator vessel 10 avoided or at least reduced. The respectively fed volume and the holding time are coordinated so that trailing TMA in the holding time for a sufficiently long period of time in the line 12 lingers to be tempered again substantially to the internal temperature.

Based on a maximum expected consumption of TMA per unit of time, the person skilled in the art can here determine both a corresponding predetermined volume and corresponding intake and holding cycles which make it possible to adequately fill the TMA evaporator vessel with appropriately tempered TMA.

For example, the predetermined volume may be in the range of 10-100 ml, preferably in the range of 20 to 30 ml, for example average consumption per hour. A corresponding volume would be tempered without further within corresponding holding cycles in the range of 1 hour.

A further advantageous feature for keeping the vapor pressure constant in the TMA evaporator vessel is that the volume of liquid TMA fed in per inlet cycle is substantially smaller than the volume of the liquid TMA held in the TMA evaporator vessel, with a ratio of 1 to 30 or greater being sought here ,

The control unit 18 can be time-controlled, but it can also, for example, consumption data via the dosing unit 14 obtained and / or level data of the TMA evaporator vessel 10 , Such level data can be, for example, by an outside of the TMA evaporator vessel 10 lying ultrasonic sensor 20 or another suitable sensor, for example in the TMA evaporator vessel 10 is arranged to be detected. Based on such data, the control unit could 18 then control the inlet and holding cycles as needed.

The invention has been explained in more detail with reference to an embodiment, without being limited to the specific embodiment.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2006059187 A1 [0007]

Claims (9)

Apparatus for providing trimethylaluminum, TMA for short, comprising: a housing; a plurality of conduits for supplying gas to at least one process module in the housing; a tempering unit for controlling the temperature of the interior of the housing and the accommodated components to a predetermined internal temperature; a TMA evaporator vessel in the housing having an outlet conduit and an inlet conduit, wherein the outlet line extends from an upper region of the TMA evaporator vessel into the housing and is connected via a metering unit in the housing with at least one process module, and the inlet line extends at least partially through the housing and into the TMA evaporator vessel and is connectable to a supply line located outside the housing, the area of the inlet line lying within the housing having a predetermined volume, and a controller configured to intermittently charge TMA into the TMA vaporizer vessel in which TMA is alternately introduced into the TMA vaporizer vessel via the inlet line during an intake cycle, and not into the TMA vaporizer vessel during a hold cycle TMA in the intake line a TMA volume is introduced into the TMA vaporizer vessel during each intake cycle that is less than or equal to the predetermined volume. The apparatus of claim 1, wherein the control unit is configured to select the length of the hold cycle such that TMA in the housing portion of the inlet conduit assumes the predetermined internal temperature. Apparatus according to claim 1 or 2, further comprising a level monitoring unit for the TMA evaporator vessel, which is suitable to determine the level inside the TMA evaporator vessel via sensor and wherein the control unit is suitable, the inlet and holding cycles at least partially based on the determined Level control. Device according to one of the preceding claims, wherein the control unit is configured to receive consumption data on the metering unit and to control the intake and holding cycles at least partially based on the consumption data. The apparatus of any one of the preceding claims, wherein the predetermined volume is sized to be greater than or equal to a maximum expected TMA consumption for a predetermined period of time. Device according to one of the preceding claims wherein the upper portion of the TMA evaporator vessel is in the upper half, preferably in the upper third of the TMA evaporator vessel. Device according to one of the preceding claims, wherein the lower region of the TMA evaporator vessel is in the lower half, preferably in the lower third of the TMA evaporator vessel. Device according to one of the preceding claims, wherein the predetermined volume in the range of 10-100 ml, preferably in the range of 20 to 30 ml, and the volume of the TMA evaporator vessel in the range of 1 and 5 liters, preferably in the range of 1, 5 and 3 liters lies. Device according to one of the preceding claims, wherein the predetermined volume is at least a factor of 50, preferably by a factor of 100, smaller than the volume of the TMA evaporator vessel.

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