JP2002088477A - Method and apparatus for feeding vaporized material, and method and system for organometallic chemical vapor deposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for feeding a vaporized material by which a vaporized material can stably be fed and to provide an organometallic chemical vapor deposition method and a system therefor by which the reproducibility of a deposited film can be improved by stably feeding the vaporized thin film raw material. SOLUTION: A liquid thin film raw material composed of an organic metal is vaporized by bubbling using a carrier gas and is fed to the inside of an evacuated film deposition chamber 2. The amount of the vaporized thin film raw material to be fed to the film deposition chamber 2 is controlled so that the pressure on the feeding part of the vaporized thin film raw material to the side of the film deposition chamber 2 and the pressure difference between the pressure on the feeding side and the pressure in the film deposition chamber are respectively held to fixed ranges. Vapor deposition is performed at the inside of the film deposition chamber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for supplying a vaporized substance by vaporizing a liquid substance by bubbling using a carrier gas and supplying the vaporized substance into a reduced-pressure chamber. The present invention relates to a metal organic chemical vapor deposition method and apparatus used for forming a semiconductor film, an insulator film, a dielectric film, and the like by vaporizing a raw material and performing vapor deposition in a film formation chamber.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a conventional metal organic chemical vapor deposition apparatus (MO-CVD apparatus), a liquid thin film raw material (liquid raw material) 1 made of an organic metal is bubbled using a carrier gas. It is vaporized and supplied to the depressurized film forming chamber 3 via the mass flow controller (MFC) 2 to perform vapor deposition in the film forming chamber 3. The MFC 2 controls the flow rate of the thin film material to a constant amount so as to stably supply the vaporized thin film material into the film forming chamber 3.

[0003]

However, according to the prior art, even if the gas flow rate flowing through the MFC can be controlled well, the partial pressure of the thin film material to be transported also increases with the fluctuation of the supply pressure of the thin film material. Due to the fluctuation, the stability of the epitaxy growth operation is poor, and the reproducibility of film formation is insufficient.

The present invention has been made in view of such conventional problems, and a vapor supply method and apparatus capable of stably supplying a vapor, and a stable supply of a vaporized thin film material. It is an object of the present invention to provide a metal organic chemical vapor deposition method and apparatus capable of improving the reproducibility of film formation.

[0005]

In order to achieve the above object, a liquid supply method according to the present invention comprises the steps of: evaporating a liquid substance by bubbling using a carrier gas; A supply method, characterized in that a supply side pressure of the vaporized substance to the chamber side and a pressure difference between the supply side pressure and the chamber internal pressure are each maintained within a certain range.

In the liquid supply method according to the present invention, the supply side pressure of the vaporized substance to the chamber side and the pressure difference between the supply side pressure and the pressure in the chamber are kept within a certain range, so that the vaporized substance is removed. It is possible to stabilize the partial pressure and supply the vaporized material stably into the chamber.

[0007] A vaporizer supply device according to the present invention vaporizes a liquid substance by bubbling using a carrier gas,
What is claimed is: 1. A vapor pressure supply device for supplying a reduced pressure to a chamber, comprising: a first pressure gauge for measuring a pressure of a supply side of the vaporized substance to a chamber side; and a second pressure gauge for measuring a pressure inside the chamber. Pressure difference calculating means for calculating a difference between the value of the supply pressure measured by the first pressure gauge and the value of the pressure measured by the second pressure gauge, and the supply pressure measured by the first pressure gauge It is characterized by having pressure holding means for keeping the pressure value and the pressure difference obtained by the pressure difference calculation means within respective fixed ranges.

[0008] In the vaporizer supply device according to the present invention, the pressure holding means measures the value of the supply side pressure measured by the first pressure gauge,
The difference between the supply-side pressure obtained by the pressure difference calculation means and the pressure inside the chamber is kept within a certain range. Thereby, the partial pressure of the vaporized material can be stabilized, and the vaporized material can be stably supplied into the chamber. The pressure holding means is, for example, a flow rate control device capable of adjusting the supply amount of the vaporized thin film material from the container to the film forming chamber. In the vaporized material supply method and apparatus according to the present invention, it is preferable that the supply side pressure and the pressure difference between the supply side pressure and the chamber internal pressure be as constant as possible.

In the metal organic chemical vapor deposition method according to the present invention, a liquid thin film material composed of an organic metal is vaporized by bubbling using a carrier gas and supplied to a reduced-pressure deposition chamber. A metal-organic chemical vapor deposition method for performing vapor deposition in a chamber, wherein a supply side pressure of the vaporized thin film material to the film formation chamber side and a pressure difference between the supply side pressure and the film formation chamber pressure are constant. The supply amount of the vaporized thin film raw material to the film forming chamber is adjusted so as to be kept within the range described above.

In the metalorganic chemical vapor deposition method according to the present invention, the supply side pressure of the vaporized thin film material to the film formation chamber side and the pressure difference between the supply side pressure and the pressure in the film formation chamber are each fixed. By maintaining the range, the partial pressure of the vaporized thin film material can be stabilized, and the thin film material can be stably supplied into the film formation chamber. Thereby, the reproducibility of film formation can be improved.

The metal organic chemical vapor deposition apparatus according to the present invention is characterized in that the thin film material is vaporized by bubbling using a carrier gas from a container containing a liquid thin film material made of an organic metal, and the pressure in the film forming chamber is reduced. A first pressure gauge for measuring a supply pressure of a thin film material vaporized inside the container to a film forming chamber side, wherein the pressure is supplied to the film forming chamber and the vapor deposition is performed in the film forming chamber. And a second pressure gauge for measuring the pressure inside the film forming chamber, and a difference between a value of the supply pressure measured by the first pressure gauge and a value of the pressure measured by the second pressure gauge. Pressure difference calculation means to be sought, a flow rate control device capable of adjusting a supply amount of the vaporized thin film raw material from the container to the film forming chamber, and a value of the supply side pressure measured by the first pressure gauge,
Control means for controlling the flow rate control device such that the pressure difference calculated by the pressure difference calculation means is kept within a certain range.

In the metal organic chemical vapor deposition apparatus according to the present invention, the flow rate control device is controlled by the control means, and the value of the supply side pressure measured by the first manometer and the supply side pressure determined by the pressure difference calculation means are determined. By maintaining the difference between the pressure and the pressure inside the film forming chamber within a certain range, the partial pressure of the vaporized thin film material can be stabilized, and the thin film material can be stably supplied into the film forming chamber. Thereby, the reproducibility of film formation can be improved.

The flow control device preferably comprises one or more valves or a mass flow controller (MFC). The pressure difference calculation means and the control means,
It preferably comprises a computer having each function.

In the liquid supply method and apparatus and the metal organic chemical vapor deposition method and apparatus according to the present invention, the carrier gas is, for example, hydrogen gas. In the metal organic chemical vapor deposition method and apparatus according to the present invention, it is preferable that the supply-side pressure and the pressure difference between the supply-side pressure and the pressure in the film forming chamber are as constant as possible. In the metal organic chemical vapor deposition method and apparatus according to the present invention, the pressure inside the film forming chamber is preferably about 0.01 to 20 Torr. In addition, the liquid thin film raw material made of an organic metal is made of, for example, a substance capable of forming a semiconductor film such as diethyl zinc, an insulator film, a dielectric film, and the like.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. As shown in FIGS. 1 and 2, a metal organic chemical vapor deposition apparatus includes a container 11, a film forming chamber 12, pressure gauges P0 to P3, valves V0 to V7.
And a personal computer PC.

The container 11 is a closed container and contains liquid diethyl zinc as a thin film material (liquid material) 13 made of an organic metal. The container 11 is placed in a water bath 14 for bubbler. The water bath 14
A temperature control mechanism 15 composed of a heater is built in, and the temperature can be controlled.

As shown in FIG. 1, the container 11 is connected to a carrier gas supply side via a pipe 16 extending to near the bottom of the container. In a pipe 16 between the carrier gas supply side and the container 11, a pressure gauge P0, a valve V0, and a valve V1 are sequentially provided. The pressure gauge P0 measures the pressure on the carrier gas supply side. A pressure gauge P1 is provided in a pipe 16 between the valve V0 and the valve V1. The pressure gauge P1 measures the pressure between the valve V0 and the valve V1. A valve V2 is provided in the pipe 16 extending to P1.

The container 11 is connected to a film forming chamber 12 via a pipe 16 extending to an upper part in the container 11. Piping 16 between the container 11 and the film forming chamber 12
Is provided with a valve 3, a valve 4 and a valve 5 in this order. The opening of the valve 4 can be adjusted by a driving unit 4a. The valve 4 is capable of adjusting the supply amount of the vaporized thin film raw material 13 from the container 11 to the film forming chamber 12 by adjusting the opening degree. Valve 2 consists of valve 4 and valve 5
Is connected to the pipe 16 between the two.

The film forming chamber 12 is connected via a pipe 16 to an exhaust valve V6 and a rotary pump RP. The opening of the exhaust valve V6 can be adjusted by an instruction. Further, the film forming chamber 12 sequentially includes an MFC, a valve V7, and a gas source gas supply side CO2 through a pipe 16.
It is connected to the. The gas source gas supply side CO2 supplies carbon dioxide into the film formation chamber 12. The film forming chamber 12 is connected to a pressure gauge P2 via a pipe 16. The pressure gauge P2 measures the pressure inside the film forming chamber 12. The container 11 is connected to a pressure gauge P3 via a pipe 16. The pressure gauge P3 measures the pressure in the container 11.

The pressure gauges P0, P1 and P3 are provided with a valve V
When 0 and V1 are open, they show the same pressure value. The pressure value coincides with the pressure on the supply side of the thin film material vaporized inside the container 11 to the film forming chamber 12 side. Pressure gauge P1,
Pressure gauge P2, drive unit 4a of valve 4, and valve V6
Is connected to the transmission / reception unit of the personal computer PC. The personal computer PC includes a pressure difference calculating unit that calculates a difference between a value of the supply pressure measured by the pressure gauge P1 and a value of the pressure measured by the pressure gauge P2, a value of the supply pressure measured by the pressure gauge P1, Control means for controlling the valve 4 so that the pressure difference calculated by the pressure difference calculation means is kept constant.

With such a configuration, the metal organic chemical vapor deposition apparatus vaporizes the thin film raw material 13 from the container 11 by bubbling using a carrier gas, and supplies the thin film raw material 13 into the depressurized film forming chamber 12. The vapor deposition is performed in the step 12.

The metal organic chemical vapor deposition apparatus is shown in FIG.
As shown in the figure, using MFC instead of valve V4,
The supply amount of the vaporized thin film raw material from the container 11 to the film forming chamber 12 may be adjusted.

Next, the operation procedure of the metal organic chemical vapor deposition apparatus will be described. 1) First, all valves V0, V1, V2, V3, V
4. Confirm that V5, V6, and V7 are closed.

2) Open the valve V6 to reduce the pressure in the film forming chamber to, for example, 5 × 10 (-5) Torr or less.
The pressure in the film forming chamber can be measured by the pressure gauge P2.

3) Open the valve V5. Thereby, the flow path from the valve V2 to the film forming chamber 2 and the valve V
The flow paths from 4 to the film formation chamber 2 all match the pressure inside the film formation chamber.

4) The valve V7 is opened to allow a certain amount of the gaseous source gas to flow into the inside of the film forming chamber 2, and the valve V6 is adjusted to set the pressure in the film forming chamber to a constant value. The gas source gas flowing into the film forming chamber 2 from the gas source gas supply side CO2 is, for example, carbon dioxide, and the fixed flow rate is, for example, 20 sccm. The pressure in the film forming chamber is set to, for example, 5 mbar.

5) Pressure inside the container 1 indicated by the pressure gauge P3 and three valves V0, V1, V indicated by the pressure gauge P1
It is confirmed that the pressure in the pipe closed in step 2 is lower than the carrier gas supply side pressure indicated by the pressure gauge P0. After confirmation, the valve V0 is opened, and it is confirmed that the pressure value of the pressure gauge P0 matches the pressure value of the pressure gauge P1.
Open 1 and confirm that the pressure value of the pressure gauge P0, the pressure value of the pressure gauge P1, and the pressure value of the pressure gauge P3 match.

6) The pressure in the vessel 1 indicated by the pressure gauge P3 is larger than the pressure in the film formation chamber indicated by the pressure gauge P2. For example, the pressure in the film formation chamber is 5 m.
In the case of bar, after confirming that the value is larger, the valve V3 is opened. Further, the pressure in the film forming chamber indicated by the pressure gauge P2 is a constant film forming pressure, for example, 1
The opening of the valve V4 is adjusted so that the pressure becomes Torr.

7) In this case, the opening degree of the valve V4 is adjusted by
The drive unit of the valve V4 from the personal computer PC so that the difference between the pressure value in the pipe indicated by the pressure gauge P1 and the pressure value in the film forming chamber indicated by the pressure gauge P2 is constant. 4a to send a control signal.

8) After completion of the film formation, first, the valve V7 is closed. Further, while operating the rotary pump RP, and closing the valve V3 while keeping the valve V6 open,
Immediately thereafter, the valve V1 is also closed. Thereafter, the valve V0 is also closed, the valve V4 is fully opened, and the valve V3 and the valve V
Exhaust all gases between 4 After a sufficient time has passed since the value of the pressure in the film forming chamber indicated by the pressure gauge P2 indicates the lower limit, the valve V4 is also closed. The valve V2 is opened, the valve V0 is also opened, and the valves are closed in the order of the valves V5, V2, and V0 while flowing the carrier gas. After a sufficient time has passed since the pressure in the film forming chamber was reduced to a vacuum and the value of the pressure gauge P2 indicated the lower limit, the valve V6 was closed. Finally, the rotary pump RP is stopped.

The metal organic chemical vapor deposition apparatus uses a valve V4
Is controlled by a personal computer PC (control means), and the thin film raw material 1 measured by the pressure gauges P0, P1, and P3.
And the personal computer PC
By keeping the difference between the supply pressure obtained by the (pressure difference calculating means) and the pressure inside the film forming chamber 2 measured by the pressure gauge P2 constant, the partial pressure of the vaporized thin film raw material is stabilized, The raw material can be stably supplied into the inside of the film forming chamber 2. Thereby, the reproducibility of film formation can be improved.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the structure shown in the above-mentioned embodiment of the invention shown in FIG.
The gaseous raw material to flow to CO2, the flow rate is 100 sccm,
The thin film material (liquid material) is diethyl zinc, the carrier gas is H2, the flow rate is 20 sccm, the temperature of the water bath 4 is 65 ° C., and the substrate for film formation is a sapphire substrate (Al 2 O 3).
3) The size of the R surface and the substrate is 30 mm × 17 mm × 0.8
mm (t) and the growth substrate temperature was set to 550 ° C.

In the embodiment, the pressure P3 is set to 100 Torr,
The pressure P2 was set to 1 Torr, the pressure value sampling time interval was set to 0.33 seconds, and the film formation time was set to 1 hour. The pressure fluctuation shift amount at the time of film formation is ± 0.3 Torr or less for 100 Torr of P3, and ± 0.3 Torr for 1 Torr of P2.
It was 0.002 Torr or less.

As a comparative example, in the configuration shown in the embodiment of the invention, instead of the valve V4, the MF adjusted to a fixed opening degree
Film formation was performed using C. The set value of the MFC was set to 20 sccm, and the film formation time was set to 1 hour. The flow rate fluctuation at the time of film formation is ± 0.1 sc as a display value for 20 sccm.
cm or less.

In the examples and comparative examples, the film formation was studied 12 times continuously in each system, and the ZnO was almost at the center of the substrate.
The thickness was measured. The results are shown in Table 1 and FIG.

[0036]

[Table 1]

As shown in Table 1 and FIG. 5, it was found that the film formation of the example can obtain a very stable growth thickness as compared with the film formation of the comparative example. In other words, a constant thin film source gas flow rate is fed into the film forming chamber for a certain period of time, and the difference between the supply side pressure of the thin film source and the difference between the supply side pressure and the pressure inside the film forming chamber is made constant. By controlling the flow rate of the vaporized thin film material while monitoring, remarkably stable reproducibility of the film thickness was obtained.

[0038]

According to the method and the apparatus for supplying a vapor according to the present invention, the vapor can be supplied stably, and according to the method and the apparatus for the metal organic chemical vapor deposition according to the present invention, the vaporized substance can be supplied. By supplying the thin film material stably, the reproducibility of film formation can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an organometallic chemical vapor deposition apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view of the metal organic chemical vapor deposition apparatus shown in FIG.

FIG. 3 is a schematic diagram showing another configuration of the metal organic chemical vapor deposition apparatus according to the embodiment of the present invention.

4 is a graph showing the relationship between the number of trials of film formation performed by the metal organic chemical vapor deposition apparatus shown in FIG. 1 and the thickness at the center position.

FIG. 5 is a schematic view showing a conventional metal organic chemical vapor deposition apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Container 12 Film-forming chamber 13 Thin film raw material 14 Water bath 15 Temperature control mechanism 16 Piping P0-P3 Pressure gauge V0-V7 Pressure gauge PC Personal computer RP Rotary pump

Continuation of the front page (72) Inventor Masahiro Noguchi 3 Shinmei-do, Nakaname, Shimada-cho, Shibata-cho, Shibata-gun, Miyagi F-term in Tohoku Ricoh Co., Ltd. (Reference) 4K030 AA11 AA16 EA01 JA05 JA09 KA39 KA41

Claims (4)

[Claims] 1. A vapor supply method for vaporizing a liquid substance by bubbling using a carrier gas and supplying the vaporized substance into a decompressed chamber, comprising: a supply side pressure of the vaporized substance to a chamber side; A liquid supply method characterized in that a pressure difference between a supply side pressure and a pressure in a chamber is kept within a certain range. 2. A vapor supply apparatus for vaporizing a liquid substance by bubbling using a carrier gas and supplying the vaporized substance into a decompressed chamber, wherein a supply pressure of the vaporized substance to the chamber is measured. A first pressure gauge, a second pressure gauge that measures the pressure inside the chamber, and a difference between a value of the supply pressure measured by the first pressure gauge and a value of the pressure measured by the second pressure gauge. And pressure holding means for keeping the value of the supply-side pressure measured by the first pressure gauge and the pressure difference calculated by the pressure difference calculating means within respective fixed ranges. A vapor supply device characterized by the above-mentioned. 3. A metal organic chemical vapor deposition in which a liquid thin film material made of an organic metal is vaporized by bubbling using a carrier gas, supplied to a reduced-pressure deposition chamber, and vapor-deposited in the deposition chamber. A method, wherein a supply side pressure of a vaporized thin film material to a film formation chamber side and a pressure difference between the supply side pressure and the pressure in the film formation chamber are each maintained within a certain range, A metal organic chemical vapor deposition method comprising adjusting a supply amount of a raw material to the film formation chamber. 4. A thin film material is vaporized by bubbling using a carrier gas from a container containing a liquid thin film material made of an organic metal, supplied to a reduced-pressure film forming chamber, and vapor-deposited in the film forming chamber. A first pressure gauge for measuring a pressure on a supply side of a thin film material vaporized inside the container to a film forming chamber side, and a pressure inside the film forming chamber. A second pressure gauge for measuring; a pressure difference calculating means for calculating a difference between a value of the supply pressure measured by the first pressure gauge and a value of pressure measured by the second pressure gauge; A flow control device capable of adjusting an amount of supply from the container to the film forming chamber; a value of the supply-side pressure measured by the first pressure gauge, and a pressure difference obtained by the pressure difference calculation means are constant. In the range And control means for controlling said flow control device as metal organic chemical vapor deposition apparatus characterized by having.