JPH05819A - Tantalum oxide thin film manufacturing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] Tantalum oxide thin film production that can control the actual flow rate of organic tantalum compound raw material, can supply a stable amount of raw material, and can form a tantalum oxide thin film with a high thin film deposition rate. Provide the device. [Configuration] The liquid Ta is directly controlled by the liquid flow controller 8.
After controlling the flow rate of (OC ₂ H ₅ ) ₅ , it is supplied to the three-way valve 9, and the oxygen-containing gas 16 and the inert gas 10 composed of Ar are supplied.
And mixed gas in the three-way valve 9 and Ta (OC ₂ H
₅ ) ₅ is vaporized in a mist to vaporize it and vacuum chamber 1
A tantalum oxide thin film is deposited on the substrate 3 by thermal decomposition and reaction inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a tantalum oxide thin film useful as a capacitive insulating film such as DRAM (dynamic ram).

[0002]

2. Description of the Related Art In recent years, a raw material gas is heated and decomposed in a vacuum chamber.
The CVD method (chemical vapor deposition method) of reacting to form a thin film on a substrate has been attracting attention as a useful means for forming a thin film of a semiconductor, a dielectric, or the like. Also in the forming method, it has been attempted to manufacture a thin film by a chemical vapor deposition method using a CVD apparatus. In this case, a so-called CVD apparatus having a vacuum chamber that can normally be heated is used.

A conventional tantalum oxide thin film manufacturing apparatus will be described below with reference to the drawings. Figure 4 shows the conventional C
It is a schematic diagram showing the composition of the tantalum oxide thin film manufacturing device (CVD device) used for the tantalum oxide thin film formation method by the VD method.

Conventionally, a tantalum oxide thin film has been produced by a CVD apparatus using a liquid organic tantalum compound typified by liquid Ta (OC ₂ H ₅ ) ₅ and oxygen gas as raw materials.

In FIG. 4, the liquid raw material Ta (OC
_Since it is difficult to directly control the actual flow rate of ₂ H ₅ ) ₅ , the flow rate control device 32 controls the flow rate of the gas to 1000 sccm with an inert gas 21 such as He or Ar, and the heater 2
The gas introduction tube 2 heated to about 150 ° C. by the heater 30 by bubbling Ta (OC ₂ H ₅ ) ₅ in the ampoule 23 whose temperature is controlled to about 130 ° C. by 2
The raw material was introduced into the vacuum chamber 24 through No. 6.

100 sccm by the flow controller 33
The oxygen gas 31 whose flow rate is controlled is also introduced into the vacuum chamber 24 at the same time, and these raw material gases introduced into the vacuum chamber 24 are heated to about 450 ° C. by a heater 25 capable of heating the vacuum chamber 24.
The vacuum chamber 2 is heated to a certain degree and decomposed and reacted.
A tantalum oxide thin film is formed on a substrate 27 made of polysilicon, tungsten silicide (WSi), or the like, which is arranged in the substrate 4.

However, in such an apparatus, when the apparatus configuration changes, the flow rate of the organic tantalum raw material gas is likely to change and it is difficult to stably supply the raw material, and the liquid organic tantalum compound is bubbled with an inert gas to produce the organic tantalum compound. To supply a large amount of inert gas,
There are drawbacks such as a low deposition rate of the tantalum oxide thin film.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and can control the actual flow rate of an organic tantalum compound raw material, and thus can supply a stable amount of the raw material, and a tantalum oxide thin film having a high thin film deposition rate. An object of the present invention is to provide a tantalum oxide thin film manufacturing apparatus capable of forming a film.

[0009]

To achieve the above object, a tantalum oxide production apparatus of the present invention introduces a vaporized substance or a spray of a liquid organic tantalum compound, an oxygen-containing gas and an inert gas, and thermally decomposes them. .A liquid flow rate control for controlling the flow rate of the liquid organic tantalum compound in a liquid state in a thin film manufacturing apparatus having a heatable vacuum chamber equipped with a heater for forming a tantalum oxide thin film by a chemical vapor deposition method for reacting A device, a liquid organic tantalum compound whose flow rate is controlled by the liquid flow rate control device, and a mixed gas of the oxygen-containing gas and an inert gas are merged, and the liquid organic tantalum compound is vaporized or atomized by the mixed gas flow. It is characterized by having a three-way valve provided with a passage for introducing the mixed gas together with the mixed gas into the vacuum chamber.

[0010]

The tantalum oxide production apparatus of the present invention is a tantalum oxide thin film formed by a chemical vapor deposition method in which a vaporized substance or a spray of a liquid organic tantalum compound and an oxygen-containing gas and an inert gas are introduced and thermally decomposed and reacted. In a thin film forming apparatus having a heatable vacuum chamber having a heater for forming a liquid, a liquid flow rate control device for controlling the flow rate of the liquid organic tantalum compound in a liquid state, and a flow rate control by the liquid flow rate control device. Liquid organic tantalum compound,
Three sides provided with a passage for introducing the oxygen-containing gas and a mixed gas of an inert gas into the vacuum chamber together with the mixed gas as a vaporized or atomized substance of the liquid organic tantalum compound by the mixed gas flow. Because it has a valve,
The liquid flow rate controller can directly control the flow rate of the liquid organic tantalum raw material in the liquid state, and since the liquid organic tantalum compound can be vaporized or atomized with the three-way valve, the need for bubbling is eliminated and the flow rate of the inert gas is reduced. be able to. Therefore, the amounts of the organic tantalum raw material and the oxygen-containing gas can be relatively increased.

Therefore, the supply amount of the organic tantalum raw material is always stable regardless of the apparatus configuration, the partial pressure of the organic tantalum raw material gas and the oxygen-containing gas with respect to the inert gas is increased, and the deposition rate of the tantalum oxide thin film can be increased. A thin film manufacturing apparatus can be provided.

[0012]

EXAMPLE FIG. 1 is a schematic view of an apparatus for producing a tantalum oxide thin film used in an example of the present invention. 1 is evacuated to a vacuum of 1 Torr by the vacuum exhaust device 2 in the vacuum chamber. 3 is a vacuum chamber 1
In this embodiment, a substrate made of polysilicon was used. The vacuum chamber 1 is heated to 250 ° C. by a heater 4 provided outside the vacuum chamber 1, and
The substrate 3 is heated by the heater 5 to an appropriate temperature of about 450 to 600 ° C. The liquid organic tantalum compound Ta (OC ₂ H ₅ ) ₅ in the ampoule 6 is pressurized by the He gas 7 which is an inert gas, and introduced into the liquid flow rate controller 8. Liquid Ta (OC ₂ H ₅ ) ₅ whose flow rate is controlled to 0.01 g / min is introduced into the three-way valve 9 from the liquid organic tantalum compound supply pipe 14, and the inert gas whose flow rate is controlled to 100 sccm by the flow control device 15. Is A
100 sccm by r gas 10 and flow controller 17
The oxygen-containing gas (oxygen gas is used in this embodiment) 16 whose flow rate is controlled is sprayed or vaporized in the three-way valve 9 by the mixed gas joined in the gas introduction pipe 13, and then the three-way valve 9 is used. The heater 12 for heating the gas introduction pipe 11 connecting the exhaust passage of
It is introduced into the vacuum chamber 1 through the gas introduction pipe 11 heated to 0 ° C. The introduced raw material mixed gas reacts near the surface of the substrate 3, and a tantalum oxide thin film is deposited on the substrate 3.

In order to explain the mechanism of the three-way valve 9 used above, FIG. 2 shows a schematic structural diagram of the three-way valve used in this embodiment. In FIG. 2, 9 is a three-way valve, 41 is a vertically movable valve,
43 is a housing of a three-way valve, 46 is a valve fitting hole in which the valve 41 is slidable up and down, 42 is a valve movable connected to an appropriate movable device (not shown) for vertically moving the valve. The member, 44, is a mixed gas introduction passage of an oxygen-containing gas and an inert gas which is connected to the gas introduction pipe 13, and has a diameter reduced near the valve 41. Further, 45 is a discharge passage connected to the gas introduction pipe 11 connecting with the vacuum chamber 1, 12 is a heater for heating the gas introduction pipe 11, 47 is a liquid which has passed through the liquid flow rate control device in FIG. A nozzle connected to the organic tantalum compound supply pipe 14 for supplying a liquid organic tantalum compound.

In FIG. 2, the position of the valve 41 in the valve fitting hole 46 is adjusted by the valve movable member 42, so that the liquid organic tantalum compound supplied from the liquid organic tantalum compound supply pipe 14 is supplied from the tip of the nozzle 47. When done,
Since the passage of the mixed gas introduction passage 44 of the oxygen-containing gas and the inert gas which is connected to the gas introduction pipe 13 is narrow, the flow velocity of the mixed gas passing through the mixed gas introduction passage 44 is accelerated and the mixed gas is supplied from the nozzle 47. The liquid organic tantalum compound as a spray passes through the discharge passage 45, is supplied to the gas introduction pipe 11 heated by the heater 12, is vaporized, and is introduced into the vacuum chamber 1.

FIG. 3 shows the deposition rate of the tantalum oxide thin film formed by the apparatus shown in FIG. 1 of the embodiment of the present invention (shown by white circles in FIG. 3) and tantalum oxide formed by the conventional apparatus shown in FIG. The deposition rate of the thin film (indicated by a black circle in FIG. 3) is shown. When deposited by the conventional apparatus shown in FIG. 4, the deposition rate of the tantalum oxide thin film is about 25 Å / min when the substrate temperature is 500 ° C., whereas the tantalum oxide thin film deposited by the apparatus of the present invention shown in FIG. The deposition rate of the thin film is about 100 Å / min, and when the substrate temperature is 550 ° C., the deposition rate is about 60 Å / min in the conventional apparatus, whereas the deposition rate is about 150 Å / min in the apparatus of the present invention. min
You can see that it is.

It should be noted that the flow rate of the inert gas 21 should be controlled by the conventional device.
If the amount is too small, the deposition rate of tantalum oxide will decrease further.
Will end up. In the present invention, a liquid organic tantalum compound
An example of Ta (OC₂H_Five) _FiveBesides, for example, T
a (OC₃H₇)_FiveAnd Ta (OC_FourH₉)_FiveEtc.
Be done. These liquid organics include, but are not limited to,
The supply amount of the tantalum compound is usually 0.001 to 0.5 g /
The range of about min is preferable.

Although the substrate material is not particularly limited, for example, polysilicon, tungsten silicide (WSi) or the like is preferably used. The temperature of the inner wall of the vacuum chamber is usually about 200 to 400 ° C, and the temperature of the gas introducing pipe 11 is preferably about 120 to 300 ° C.
The pressure in the vacuum chamber is generally in the range of about 0.5 to 10 Torr, and the inert gas is not particularly limited, but Ar or He is usually used, and the oxygen-containing gas is Any gas can be used as long as it can heat and decompose an organic tantalum compound under vacuum to form tantalum oxide. Specifically, oxygen gas, N ₂ O gas and the like are usually used, but the gas is not limited to these. ..

The flow rates of these inert gas and oxygen-containing gas are not particularly limited, but usually 50.
A range of about 1000 sccm is suitable.

[0019]

EFFECT OF THE INVENTION The supply amount of the organic tantalum raw material is always stable, the flow rate of the inert gas can be reduced, the partial pressure of the organic tantalum raw material gas and the oxygen-containing gas relative to the inert gas is increased, and the tantalum oxide thin film A tantalum oxide thin film manufacturing apparatus capable of increasing the deposition rate can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view of a tantalum oxide thin film manufacturing apparatus in one embodiment of the present invention.

FIG. 2 is an end view of a schematic cross section of a three-way valve of the tantalum oxide thin film manufacturing apparatus in one embodiment of the present invention.

FIG. 3 is a graph showing a deposition rate with respect to a substrate temperature of a tantalum oxide thin film when an apparatus according to an embodiment of the present invention and an apparatus according to a conventional example are used.

FIG. 4 is a schematic view of a conventional tantalum oxide thin film manufacturing apparatus.

[Explanation of symbols]

 1 Vacuum Chamber 2 Vacuum Evacuation Device 3 Substrate 4 Heater 5 Heater 6 Ampoule 7 Inert Gas 8 Liquid Flow Control Device 9 Three-way Valve 11 Gas Inlet Pipe 12 Heater 13 Gas Inlet Pipe 14 Liquid Organic Tantalum Compound Supply Pipe 15 Flow Control Device 16 Oxygen Contained gas 17 Flow control device 21 Inert gas 22 Heater 23 Ampoule 24 Vacuum chamber 25 Heater 26 Gas introduction pipe 27 Substrate 29 Vacuum exhaust device 30 Heater 31 Oxygen gas 32 Flow control device 33 Flow control device 41 Valve 42 Valve movable member 43 Three-way Valve housing 44 Mixed gas introduction passage 45 Discharge passage 46 Valve fitting hole 47 Nozzle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatoshi Kitagawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Ken Kamata, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Takashi Hirao 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroshi Nishizato 14-3 Shinsen, Narita, Chiba Applied Technology Japan Co., Ltd. Technology Center

Claims (1)

Claim: What is claimed is: 1. A tantalum oxide thin film formed by a chemical vapor deposition method in which a vaporized substance or a spray of a liquid organic tantalum compound and an oxygen-containing gas and an inert gas are introduced and thermally decomposed and reacted. In a thin film manufacturing apparatus having a heatable vacuum chamber equipped with a heater for forming, a liquid flow rate control device for controlling the flow rate of the liquid organic tantalum compound in a liquid state, and a flow rate control by the liquid flow rate control device. In order to introduce the liquid organic tantalum compound and the mixed gas of the oxygen-containing gas and the inert gas into the vacuum chamber together with the mixed gas as the vaporized or atomized substance of the liquid organic tantalum compound by the mixed gas flow. An apparatus for producing a tantalum oxide thin film, comprising a three-way valve having the passage of 1.