KR20140004007A - Source container and method for using source container - Google Patents

Abstract

When supplying a gas phase raw material, which sublimates a precursor of a raw material, to a process chamber for performing film forming treatment on an object to be treated, a method prepared by the present invention efficiently sublimates the precursor inside a raw material container. Trays (41), which accommodate the precursor (50), in multiple layers are accumulated on top of each other inside a housing (24) having an opening (30) that communicates with the process chamber (2). Each tray (41) comprises: an inlet (a hole) (45) which introduces carrier gas into the tray (41); an outlet (a gap) (28) which communicates with the opening (30) as the carrier gas leaks along with the gas phase raw material of the precursor (50); and a cover (46) which can be opened and closed and holds the precursor (50) inside the tray (41).

Description

SOURCE CONTAINER AND METHOD FOR USING SOURCE CONTAINER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process chamber for performing a film forming process on a target object, a raw material container accommodating a precursor when supplying a vapor phase raw material obtained by sublimating a precursor of a film forming raw material, and a method of using the raw material container.

In the metallization process for the manufacture of integrated circuits, a substrate, which is a workpiece, is placed in a process chamber, and a gaseous raw material obtained by subliming a precursor of a raw material from a raw material container, for example, CO and the like is introduced into the process chamber as a carrier gas. The film formation process is performed on the substrate.

At this time, a metal carbonyl precursor, such as ruthenium carbonyl, is used as the precursor. In order to efficiently sublimate such a low vapor pressure precursor, the raw material container has a multistage tray structure inside, which is a precursor in a carrier gas flow path. The surface area of the is secured. Such a raw material container is disclosed by patent document 1, for example.

Japanese Patent Publication No. 2008-522029

By the way, in the case of the raw material container of a multistage tray structure as shown in the said patent document 1, since each tray becomes shallow, precursor may overflow from the tray of an upper stage to the tray of a lower stage by the vibration or inclination at the time of conveyance. . A sufficient amount of sublimation cannot be obtained from the tray containing fewer precursors, and as a result, the supply amount of the gaseous-phase raw material may be insufficient, and thus stable film forming may not be performed, which may cause a defect in the film forming process.

This invention is made | formed in view of the problem with the conventional raw material container as mentioned above, and an object of this invention is to sublimate efficiently the precursor in a raw material container.

MEANS TO SOLVE THE PROBLEM In order to solve the said problem, this invention is a raw material container which accommodates the said precursor for supplying the gaseous raw material which sublimed the precursor of a raw material to the process chamber which performs the film-forming process to a to-be-processed object, and is opened to communicate with the said process chamber. In a housing having a stack, trays for accommodating the precursor are stacked in multiple stages up and down, wherein each tray has an inlet for introducing a carrier gas into the tray and a carrier gas flows out along with the gaseous raw material of the precursor to communicate with the opening. It has an outlet to make and the cover which hold | maintains the said precursor in the said tray is provided so that opening and closing is possible.

In the said raw material container, it is preferable that the said cover covers the upper part of the said precursor, and it is in close contact with the back surface side of the tray of the upper end of the said cover at the time of opening. The cover may be closed by its own weight when the inside of the housing is at atmospheric pressure, and may be pulled upward when the inside of the housing is depressurized. When the cover is closed, it is preferable to contact the upper surface of the precursor in the tray.

In the said raw material container, the said cover may be equipped with the basket of mesh shape on the back surface, and the precursor may be accommodated in the said basket. The lid may be formed of the same material as the precursor. The precursor may be a solid precursor of a metal carbonyl film.

According to the present invention, there is provided a method of using a raw material container, wherein the inside of the housing is depressurized to a pressure at the time of film forming treatment, and then the lid is opened. In the use method of this raw material container, you may start pressure reduction with the start of supply of the said carrier gas.

According to the present invention, by closing the lid of the tray during transportation, it is possible to prevent the precursor from flowing out of the tray even if the raw material container is tilted or shaken. On the other hand, in the film formation process, if the cover is opened, the vaporized raw material is transported by the carrier gas while ensuring sufficient conductance, so that stable film formation can be performed. That is, since a sufficient sublimation amount can be maintained for a long time, a stable film formation rate can be maintained for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the film-forming system using the raw material container of this invention.
2A and 2B are longitudinal sectional views showing an example of an embodiment of the raw material container of the present invention, and Fig. 2A shows a closed state, and Fig. 2B shows a opened state.
3 is a perspective view of a tray of the raw material container of FIG. 1.
4 is a cross-sectional perspective view of the raw material container of FIG. 1.
5A and 5B are longitudinal cross-sectional views showing different embodiments of the raw material container of the present invention, in which Fig. 5A shows the lid closed and Fig. 5B shows the lid open.
6A and 6B are longitudinal cross-sectional views showing different embodiments of the raw material container of the present invention, and Fig. 6A shows a closed state, and Fig. 6B shows a closed state.
7 is a partially enlarged view of a lid of the raw material container of FIGS. 6A and 6B.
8 is a flowchart showing a procedure of a film forming process using the raw material container of the present invention.
9 is a graph comparing the change of the pressure of the present invention and the conventional vacuum exhaust.
10A and 10B are longitudinal sectional views showing different embodiments of the raw material container of the present invention, in which FIG. 10A shows a closed state, and FIG. 10B shows a opened state.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in this specification and drawing, in the element which has substantially the same functional structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

FIG. 1 shows an example of a film forming system 1 in which a thin film such as a ruthenium (Ru) metal film is deposited on a substrate W to form a film. The film-forming system 1 is equipped with the process chamber 2 which has the board | substrate holder 11 which supports the board | substrate W. As shown in FIG. The process chamber 2 is connected to the raw material container 4 via the gas phase raw material supply part 3. In the film forming system 1, the temperature of the process chamber 2, the gas phase raw material supply unit 3, the raw material container 4, and the operation of the pump described later are controlled by the control unit 5.

The process chamber 2 and the raw material container 4 are connected to the vacuum pump 6 via the duct 12 provided in the middle of the gaseous-phase raw material supply part 3. The vacuum pump 6 exhausts from the process chamber 2, the gas phase raw material supply part 3 and the raw material container 4, and a pressure suitable for forming a thin film on the substrate W in the process chamber 2, and also the raw material. The vessel 4 is brought to a pressure suitable for vaporizing the precursor.

The raw material container 4 is configured to store the precursor of the film forming raw material and also heat it to a temperature sufficient to sublimate or evaporate the precursor. The raw material which became into a gaseous state in the raw material container 4 is introduce | transduced into the gaseous-phase raw material supply part 3. The precursor is, for example, a solid film precursor, and metal carbonyl, specifically, ruthenium carbonyl (Ru ₃ (CO) ₁₂ ) or the like is used. In addition, as a precursor, for example, rhenium carbonyl (Re ₂ (CO) ₁₀ ) or W (CO) ₆ , Mo (CO) ₆ , Co ₂ (CO) ₈ , Rh ₄ (CO) ₁₂ , Cr (CO) ₆ or Os ₃ (CO) ₁₂ may be included. Hereinafter, the case of a solid precursor is demonstrated as an example of the Example of this invention.

The raw material container 4 is temperature-controlled by the control part 5 in order to achieve the temperature which sublimes a solid precursor. When the precursor of the raw material is heated to sublimate, a carrier gas flows to transport the gaseous raw material to the process chamber 2. Carrier gas is sent from the carrier gas supply part 7 controlled by the control part 5 to the raw material container 4 via the carrier gas supply pipe 13. As the carrier gas, for example, carbon monoxide (CO) is used. Although not shown, the carrier gas supply unit 7 may include a gas source, one or two or more control valves, one or two or more filters, and a mass flow controller.

The vapor phase raw material of the precursor sublimated in the raw material container 4 flows with a carrier gas, and flows into the process chamber 2 through the vapor phase raw material supply part 3. In order to prevent the vapor phase raw material of the precursor from condensation or decomposition, the vapor phase raw material supply part 3 is temperature controlled by the control part 5. What is necessary is just to set the temperature of the gaseous-phase raw material supply part 3 about the same as the temperature of the raw material container 4, for example.

The gas phase raw material introduced into the upper part of the process chamber 2 is dispersed through the gas phase raw material distribution plate 14, and flows into the processing chamber 20 above the substrate W. The gas phase raw material dispersion plate 14 may be temperature controlled by the controller 5. The temperature of the gas phase raw material dispersion plate 14 may be, for example, approximately equal to or higher than the temperature of the gas phase raw material supply part 3.

When the vapor phase raw material of a precursor flows into the process chamber 20, a vapor phase raw material adsorb | sucks on the surface of the board | substrate W, and a thin film is formed on the board | substrate W. FIG. The substrate holder 11 is temperature controlled by the controller 5. The temperature of the substrate W is raised to about 200 ° C, for example. In addition, you may control the temperature of the wall surface of the process chamber 2 with the control part 5, and may control the temperature in the process chamber 2.

In the above film-forming system 1, an example of the Example of the raw material container of this invention is demonstrated below.

2A and 2B are sectional views of the raw material container 4 according to the present embodiment. The raw material container 4 is in close contact with a disk-shaped bottom plate 21, a substantially cylindrical side plate 22 having a flange 22a at the top, and a flange 22a at the upper side of the side plate 22, 30 has a housing 24 composed of a top plate 23 formed thereon. The opening 30 communicates with the process chamber 2 of the film forming system 1 via the vapor phase raw material supply unit 3 shown in FIG. 1. The housing 24 is made of a material having excellent thermal conductivity, for example, aluminum, and may be coated.

The heater 31 is attached to the outer side of the side plate 22 of the housing 24 and temperature-controlled so that the inside of the raw material container 4 may be maintained at 80 degreeC, for example by the control part 5 shown in FIG. As mentioned above, when the inside of the raw material container 4 is heated to predetermined temperature, a precursor will sublimate and the gaseous-phase raw material of a precursor will be produced | generated. This gas phase raw material is conveyed to the process chamber 2 via the gas phase raw material supply part 3.

Moreover, the housing 24 has the carrier gas inlet 32 which penetrates the top plate 23, as shown to FIG. 2A and FIG. 2B, for example, and as shown in FIG. 1, the carrier gas supply pipe 13 ) Is connected to the carrier gas supply part 7 in a hermetic shape via the ().

As shown to FIG. 2A and FIG. 2B, the raw material container 4 has the tray 41 of several steps laminated | stacked in the up-down direction inside the housing 24. As shown in FIG. Each tray 41 has an outer circumferential wall 42, a bottom portion 43, and an inner circumferential wall 44 as shown in FIG. 3 in the present embodiment, and each tray 41 has a central portion in common. have. Thereby, when the tray 41 is laminated | stacked, the cavity part 25 is formed in the longitudinal direction in the center part of the raw material container 4, as shown to FIG. 2A and FIG. 2B. The lowermost tray 41 is mounted on the bottom plate 21 of the housing 24, and each tray 41 of the upper end has a bottom 43 stacked on the upper end of the outer peripheral wall 42 at the lower end. As shown to FIG. 2A and FIG. 2B, the clearance gap is formed between the outer peripheral wall 42 of each tray 41, and the side plate 22 of the housing 24. As shown in FIG. In addition, a gap 28 is formed between the upper end of the inner circumferential wall 44 of each tray 41 and the bottom 43 of the straight tray 41 in order to secure a flow path of carrier gas described later. . In each of these trays 41, the precursor 50 of film-forming raw material is accommodated. The precursor of the film forming raw material may be, for example, a solid precursor, or may be a solid powder or a solid tablet. In addition, in the example shown to FIG. 2A and FIG. 2B, although the stage of the tray 41 of the raw material container 4 is five stages, it is not limited to five stages.

3, in the upper part of the outer peripheral wall 42 of each tray 41, the some hole 45 as an inlet which introduces carrier gas into the tray 41 is formed. Thereby, the carrier gas supplied toward the raw material container 4 from the carrier gas supply part 7 (refer FIG. 1) is introduce | transduced into the raw material container 4 from the carrier gas introduction port 32 (refer FIG. 2A), In addition, it enters the tray 41 through the hole 45 of each tray 41. And the center of the raw material container 4 flows through the precursor 50, and is through the clearance gap 28 (outlet) of the inner peripheral wall 44 of the tray 41, and the bottom part 43 of the tray 41 of a straight line. Flow into the cavity 25 formed in the. Therefore, when the precursor 50 sublimes, the carrier gas flows along the cavity 25 of the raw material container 4 together with the gaseous raw material, and flows out from the opening 30 formed in the upper center. In order to reliably introduce the carrier gas into the tray 41, the amount of the precursor 50 accommodated in each tray 41 is lower than the position of the hole 45 of the outer circumferential wall 42.

Each tray 41 is provided with a lid 46 covering the upper portion of the tray 41 so that the precursor 50 in the tray 41 does not overflow even when the raw material container 4 is inclined during transportation. On the other hand, in the cavity 25 in the center of the housing 24, a columnar body 26 extending in the longitudinal direction is provided, and elevating mechanisms 27 such as actuators for elevating the columnar body 26 in the vertical direction, for example. ) Is provided at the center of the bottom plate 21 of the housing 24. As shown in FIG. 4, the lid 46 of the tray 41 of each stage is connected to this pillar body 26 by the some bracket 47, for example. And when the precursor 50 in the tray 41 is not sublimated, such as at the time of conveyance of the raw material container 4, as shown in FIG. 2A, it is set as the height which the lid 46 closes the tray 41, During the film formation process, the lift mechanism 27 is operated to move the lid 46 upward. When the lid 46 is raised, as shown in FIG. 2B, the lid 46 is brought into contact with the bottom 43 of the straight tray 41. By doing in this way, the lid | cover 46 is kept warm by the heat transfer from the tray 41, the temperature of the lid | cover 46 falls, and it can prevent that a gaseous-phase raw material cools and solidifies. In addition, the means for moving the columnar body 26 up and down is not limited to an actuator, You may carry out manually as a screw or latch structure.

Moreover, as an example of the Example of this invention, you may attach a bellows as the lifting mechanism 27, and may connect the columnar body 26 to the upper end of a bellows. In this case, when the inside of the raw material container 4 is maintained at atmospheric pressure, the lid 46 is closed by the weight of the lid 46 or the pillar 26 and the bellows itself. When the raw material container 4 is depressurized in order to perform a film-forming process, and it lowers to predetermined | prescribed pressure, the atmospheric rolling force will exceed its own weight, the bellows will raise, and the cover 46 will raise accordingly. Set the bellows. According to this embodiment, the lid 41 can be naturally opened at the time of use of the raw material container 4 without any special operation.

As described above, according to the present invention, since the precursor 50 does not overflow from the tray 41 even when the raw material container 4 is inclined during transportation, the precursor 50 of the tray 41 of each stage is retained. The quantity can be kept constant, and it can be stabilized for a long time and can supply a gaseous-phase raw material efficiently.

5A and 5B show another embodiment of the present invention. The lid 46 of each tray 41 is in contact with the precursor 50 in the tray 41 to cover the upper surface of the precursor 50 and a protrusion projecting upward of the inner wall of the tray 41. Has 62. At the time of conveyance of the raw material container 4, etc., as shown in FIG. 5A, when the cover part 61 presses the upper surface of the precursor 50, not only fall of the precursor 50 but also inclination can be prevented. Therefore, the amount of the precursor 50 in the tray 41 is not deflected, and uniform gaseous raw material can be discharged. When the lid 46 is opened, the lid portion 61 is brought into contact with the bottom portion 43 of the straight tray 41. At this time, as shown in FIG. 5B, the trays 41 at each stage are gradually turned toward the upper end so that the protrusions 62 are located inward of the inner circumferential wall 44 of the straight tray 41. Is formed to be close to the outer circumferential wall 42 side.

6A and 6B show another embodiment of the present invention, and FIG. 7 is an enlarged view of a part of the lid 46 of the embodiment of FIGS. 6A and 6B. A mesh basket 63 is provided below the lid 46 of each tray 41, and the precursor 50 is accommodated in the basket 63 as well. The basket 63 has a shape and a size accommodated in the tray 41. In this case, when the lid 46 is closed, deflection of the precursor 50 can be prevented by pressing the precursor 50 in the tray 41 as shown in FIG. 6A. At the time of opening of the lid 46, as shown in FIG. 6B, the lid 46 contacts the bottom 43 of the straight tray 41, and the precursor 50 in the basket 63 moves the straight tray ( 41) is disposed on the back side. Then, the carrier gas passes between the basket 63 and the precursor 50 in the tray 41, and the carrier gas forms the gaseous raw material obtained by sublimation of the precursors 50 in the basket 63 and the tray 41. In order to convey, the surface area of the precursor 50 can be ensured more.

Next, the procedure of film-forming on a board | substrate using the raw material container of this invention is demonstrated according to FIG.

First, the substrate W is placed in the process chamber 2 of the film forming system 1 (step S1 in FIG. 8). Next, the raw material container 4 which accommodated the precursor 50 used as a film-forming raw material in the tray 41 of each stage is introduce | transduced into the film-forming system 1 (process S2 of FIG. 8).

Subsequently, heating of the raw material container 4, vacuum evacuation by the vacuum pump 6, and introduction of the carrier gas by the carrier gas supply unit 7 are performed simultaneously (step S3 in FIG. 8). Heating is performed until the inside of the raw material container 4 becomes 80 degreeC, for example. Vacuum evacuation is performed until the inside of the raw material container 4 becomes 0.1 Torr (13.3 Pa), for example.

When the lid 46 is connected to the bellows, when the inside of the raw material container 4 is depressurized to a predetermined pressure, the lid 46 is pulled up. When using an actuator or the like as the lifting mechanism 27, for example, the pressure is reduced to a predetermined pressure, for example, 0.1 Torr (13.3 Pa), and then the lid 46 is opened (step S4 in FIG. 8).

The precursor is sublimed, a gaseous raw material is generated, conveyed by the carrier gas, and sent to the process chamber 2 (step S5 in FIG. 8). In the process chamber, the substrate is heated to a substrate temperature sufficient to decompose the gas phase raw material, and the substrate is exposed to the gas phase raw material (step S6 in FIG. 8).

When the inside of the raw material container 4 in the atmospheric pressure is evacuated, the pressure in the raw material container 4 decreases rapidly, the gas flow rate in the raw material container 4 rises, and the precursor is wound up without sublimation, and the process chamber Is inhaled. For this reason, conventionally, pressure reduction was carried out gradually for a long time and trouble. In the present invention, by vacuum evacuation in a state where the lid 46 of the tray 41 is closed, the winding up of the precursor 50 can be suppressed and rapid decompression can be performed. That is, as shown in Fig. 9, the time until the processing pressure during the film formation process, is shortened by the time (t ₁₎ from the conventional time (t _2), greater the time and effort required for evacuating width Can be reduced. Moreover, since CO introduction time can also be shortened in the meantime, usage amount can be reduced and a significant cost reduction effect is acquired.

In addition, in order to suppress decomposition of the precursor from heating until the pressure is reduced to a predetermined pressure after heating the raw material container, vacuum evacuation is performed after filling the inside of the raw material container with CO. Induced by CO, the particles of the precursor rose without sublimation and fell on the substrate, whereby uniform film formation could not be performed. According to the present invention, since the lid is closed until the pressure is reduced to a predetermined pressure, the particles of the precursor that are not sublimated fall on the substrate.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these examples. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims and that they are obviously also within the technical scope of the invention.

For example, in each of the above embodiments, the lid 46 covers the upper portion of each tray 41. However, as shown in FIG. 10A, the tray 41 is directly aligned with the inner circumferential wall 44 of the tray 41. ) May be a ring-shaped lid 46 that closes the gap with the gap. In this case, at the time of opening, the lid 46 is brought into contact with the inside of the inner circumferential wall 44 of the straight tray 41, as shown in Fig. 10B.

In addition, the lid 46 according to the present invention may be formed of the same material as the precursor 50 in the tray 41. In this case, for example, in the embodiment of FIGS. 2A and 2B, the precursor 50 is disposed on both sides of the tray 41 at each stage when the lid 46 is opened, and the carrier gas passes therebetween. Therefore, the surface area of the precursor 50 becomes large and it can sublimate efficiently.

In the present invention, the shape of the tray 41 may not be annular as shown in FIG. 3. In addition, the cavity 25 of the raw material container 4 formed by the inner circumferential wall 44 of the tray 41 may not be cylindrical.

The precursor of the film-forming raw material is not limited to a solid metal carbonyl precursor and the like, but may be a liquid precursor.

1: deposition system
2: process chamber
4: raw material container
24: Housing
30: opening
41: Tray
45: hole
46: Cover
50: precursor
W: substrate

Claims (9)

A process chamber for performing a film forming process on a target object, the raw material container containing the precursor for supplying a gas phase raw material obtained by sublimating a precursor of a raw material,
In a housing having an opening communicating with the process chamber, a tray containing the precursor is stacked in multiple stages up and down,
Each tray has an inlet through which carrier gas is introduced into the tray and an outlet through which carrier gas flows out with the vapor phase raw material of the precursor and communicates with the opening, and enables opening and closing of a lid holding the precursor in the tray. The raw material container provided. The method of claim 1,
The lid covers the upper portion of the precursor, and when opened, the lid is in close contact with the rear surface side of the tray immediately above the lid. 3. The method of claim 2,
The lid is closed by self weight when the inside of the housing is at atmospheric pressure, and is pulled upward when the inside of the housing is depressurized. The method according to claim 2 or 3,
The lid is in contact with the upper surface of the precursor in the tray when the lid is closed. The method according to claim 2 or 3,
The lid is provided with a mesh basket on the back side, and the precursor container is accommodated in the basket. The method according to any one of claims 1 to 3,
The lid is formed of the same material as the precursor. The method according to any one of claims 1 to 3,
The precursor is a raw material container, characterized in that the solid precursor of the metal carbonyl film. As a use method of the raw material container in any one of Claims 1-3,
A method of using a raw material container, the pressure reduction in the housing is started while the lid is closed, and the lid is opened after the pressure in the housing is reduced to a pressure during film formation. The method of claim 8,
A method of using a raw material container is characterized by starting depressurization with the start of supply of the carrier gas.

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