JP3591218B2 - Film forming method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for forming a metal oxide film suitable for an insulating film such as tantalum oxide.
[0002]
[Prior art]
Generally, in order to manufacture a semiconductor device, a film forming process and a pattern etching process are repeatedly performed on a semiconductor wafer to produce a desired device. Among them, the film forming technology is accompanied by a higher density and higher integration of the semiconductor device. The specifications are becoming stricter year by year, and for example, even thinner oxide films such as the insulating film and gate insulating film of a capacitor in a device are required to be made thinner, and at the same time, a higher insulating property is required. Is required.
[0003]
As these insulating films, a silicon oxide film, a silicon nitride film, or the like can be used, but recently, as a material having better insulating properties, a metal oxide film such as tantalum oxide (Ta) has been used. ₂ O ₅ ) Etc. tend to be used. Although the metal oxide film exhibits a highly reliable insulating property even when it is thin, it is possible to further improve the insulating property by performing a surface modification treatment after the metal oxide film is formed. Discovered, JP-A-2-283022 And JP-A-5-247650 Discloses the technique.
[0004]
In order to form this metal oxide film, for example, a case where tantalum oxide is formed will be described. As disclosed in the above-mentioned publication, a metal alkoxide of tantalum (Ta (OC (OC ₂ H ₅ ) ₅ ) And cover it with nitrogen gas, etc.
The semiconductor wafer is maintained at a process temperature of, for example, about 400 ° C. while being supplied while being blown, and a tantalum oxide film (Ta) is formed by CVD (Chemical Vapor Deposition) in a vacuum atmosphere. ₂ O ₅ ) Are laminated.
In order to further improve the insulation properties as needed, the semiconductor wafer is carried into an atmosphere containing ozone, and the semiconductor wafer is irradiated with ultraviolet rays from a mercury lamp under atmospheric pressure to activate oxygen atoms. Are generated, and the tantalum oxide film is modified using the active oxygen atoms, thereby obtaining an insulating film having better characteristics.
[0005]
[Problems to be solved by the invention]
By the way, it is important to improve the characteristics of the insulating film as described above, but at the same time, productivity, that is, high throughput is required in order to manufacture a large number of devices of good quality. However, the film forming step and the modifying step as described above require a considerable amount of time to perform, and it is hard to say that the throughput is so good.
For example, the film forming rate of a tantalum oxide film is a film forming rate of only about 1 to 2 nm / min, and it is a major issue to significantly improve the film forming rate in order to sufficiently increase productivity. ing.
The present invention has been devised in view of the above problems and effectively solving the problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a film forming method and apparatus capable of improving a film forming rate of a metal oxide film.
[0006]
[Means for Solving the Problems]
The inventor of the present invention has earnestly studied the film formation conditions, and as a result, obtained the finding that the addition of a small amount of alcohol at the time of film formation can significantly improve the film formation rate. is there.
In order to solve the above problems, the present invention provides a film forming apparatus for forming a metal oxide film on an object to be processed, comprising: a processing container capable of being evacuated; and an object stored in the processing container. A mounting table for mounting, a raw material supply means for supplying a metal oxide film raw material in a vaporized state into the processing vessel, an alcohol supply means for supplying alcohol in a vaporized state into the processing vessel, and a vacuum inside the processing vessel. Evacuation system to pull An alcohol decomposition catalyst for accelerating the decomposition of the alcohol, Is provided.
[0007]
During the film forming process, the metal oxide film raw material is supplied in a vaporized state from the raw material supply means, and alcohol is supplied in a vaporized state from the alcohol supply means, and both are introduced into the processing vessel. The inside of the processing vessel is evacuated to a vacuum atmosphere of a predetermined pressure by a vacuum exhaust system, and a metal oxide film is deposited on the surface of the processing target on the mounting table. At this time, the film formation reaction is accelerated by the direct action of the alcohol, and water is generated by the decomposition of the alcohol. This water also promotes the film formation reaction, and as a result, the film formation reaction is greatly improved. As a result, the film forming rate can be increased. It is considered that the reason why the alcohol promotes the film formation rate is that the water generated by the decomposition of the alcohol promotes the decomposition of the metal oxide film raw material and speeds up the formation of the oxide film.
[0008]
This alcohol may be supplied to the metal oxide film raw material by a separate supply unit, or the alcohol and the metal oxide film raw material may be mixed to form a mixed solution, which is vaporized in a mixed state from the raw material supply unit. Then, it may be introduced into the processing container. In addition, in the case of the supply means of another system, it goes without saying that the addition amount of alcohol can be freely controlled even during the process. The processing temperature at this time is preferably set in the range of 250 to 450 ° C., and the amount of alcohol added is preferably set in the range of 0.1 to 20%.
A metal alkoxide can be used as a metal oxide film raw material, and the metal oxide film to be deposited contains any one of tantalum oxide, titanium oxide, zirconium oxide, barium oxide, and strontium oxide.
Further, the present inventor further studied the function of accelerating the film formation of alcohol, and found that the formed film itself functions as an alcohol decomposition catalyst for decomposing alcohol to promote the formation of water. I found
Therefore, by disposing the alcohol decomposition catalyst in the processing container, for example, above the mounting table, the decomposition of alcohol is promoted, and the film formation can be further promoted. As such an alcohol decomposition catalyst, a metal oxide can be mainly used.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a film forming method and an apparatus therefor according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic overall configuration diagram illustrating a film forming apparatus according to the present invention, and FIG. 2 is a configuration diagram illustrating a main body of the film forming apparatus. Here, tantalum oxide (Ta) is used as the metal oxide film. ₂ O ₅ )
The case of forming a film by CVD will be described.
The film forming apparatus 2 includes an apparatus main body 4, a raw material supply means 6 for supplying a metal oxide film raw material as a raw material gas in a vaporized state, and alcohol as an additive during a film forming process to improve a film forming rate. It is mainly constituted by alcohol supply means 8 which is a feature of the present invention and is added in a vaporized state.
[0010]
The raw material supply means 6 supplies a liquid metal oxide film raw material 10, for example, Ta (OC ₂ H ₅ ) ₅ Closed raw material tank 12 for storing metal alkoxide
The tank 12 is provided with a heater 14 to heat the raw material 10 to a temperature at which the raw material 10 can easily flow, for example, about 20 to 50 ° C.
In the gaseous phase portion of the raw material tank 12, the tip of a pressurized pipe 16 is introduced from above, and a flow rate controller 18 such as a mass flow controller is interposed in the pressurized pipe 16, and for example, as a pressurized gas, He gas can be introduced into the gas phase in the raw material tank 12.
[0011]
A raw material supply passage 20 made of, for example, a stainless steel tube is provided so as to connect the raw material tank 12 to the ceiling of the apparatus main body 4. It is immersed inside and located near the bottom so that the liquid raw material can be transported under pressure into the passage 20.
The raw material supply passage 20 is provided with a liquid flow controller 24 and a vaporizer 26 on the way toward the apparatus main body 4 to introduce the vaporized raw material gas into the apparatus main body 4. .
[0012]
In the raw material supply passage 20 from the raw material tank 12 to the vaporizer 26, a liquid flow rate is usually very small, for example, about 5 mg / min, so that a pipe having an inner diameter of about 1 to 2 mm is used. For the passage 20 on the further downstream side, a pipe having a large inner diameter, for example, about 10 to 20 mm is used because the gaseous raw material flows. In the raw material supply passage 20 on the downstream side of the vaporizer 26, a heat retaining heater 28 made of, for example, a tape heater is wound, and the temperature is higher than the liquefying temperature of the raw material gas and lower than the decomposition temperature, for example. The temperature is kept within the range of 150 ° C to 180 ° C.
Further, for example, He gas is supplied to the vaporizer 26 as a vaporizing gas while controlling the flow rate by a flow controller 30.
[0013]
On the other hand, the alcohol supply means 8 has a closed alcohol tank 34 for storing alcohol as a liquid additive 32. The tank 34 is provided with a heater 36 to heat the alcohol 32 so that the alcohol 32 is heated. It promotes vaporization.
A bubbling tube 38 is introduced into the alcohol tank 34, and its tip is immersed in the alcohol 32 to be positioned near the bottom. A flow controller 40 is interposed in the bubbling tube 38 and, for example, O 2 is used as bubbling gas. ₂ Gas or N ₂ By supplying gas while controlling the flow rate, liquid additives
The alcohol 32 is bubbled and vaporized.
[0014]
An alcohol supply passage 42 made of, for example, a stainless steel tube is provided so as to connect the alcohol tank 34 to the ceiling of the apparatus main body 4. The vaporized alcohol generated by bubbling is transported to the apparatus main body. The type of alcohol used as an additive is not particularly limited. For example, a lower alcohol such as methyl alcohol or ethyl alcohol, or a higher alcohol having 6 or more carbon atoms can be used. The pressurized gas supplied to the alcohol tank 34 is O ₂ Gas or N ₂ Not limited to the gas, an inert gas such as He gas or Ar gas may be used. The heating temperature of the alcohol tank 34 depends on the type of alcohol. It is preferable to set the temperature within the range of ° C.
[0015]
On the other hand, as shown in FIG. 2, the apparatus main body 4 has a processing container 46 formed of, for example, aluminum into a cylindrical shape. A feed line insertion hole 48 is formed in the center of the bottom 46A of the processing container 46, and a peripheral part is provided with a vacuum pump 54, for example, a vacuum exhaust system 54 provided with a turbo molecular pump 50 and a dry pump 52. A connected exhaust port 56 is provided so that the inside of the container can be evacuated. A plurality of, for example, about four, exhaust ports 56 are provided on the same circumference at equal intervals on the container bottom 46A, and the exhaust ports 56 are commonly connected by a vacuum exhaust system 54.
[0016]
A disc-shaped mounting table 58 made of a non-conductive material, for example, alumina is provided in the processing container 46, and a hollow cylindrical leg 60 extending downward is integrally formed at the center of the lower surface of the mounting table 58. The lower end of the leg 60 is hermetically attached and fixed to the periphery of the feeder line insertion hole 48 of the container bottom 46A with a bolt 64 or the like via a sealing member 62 such as an O-ring. Therefore, the inside of the hollow leg portion 60 is opened to the outside, and the inside of the processing container 46 is airtight.
[0017]
The mounting table 58 has embedded therein, for example, a carbon resistance heating element 66 coated with SiC, and heats a semiconductor wafer W as an object to be mounted mounted on the upper surface side to a desired temperature. I am getting it. The upper portion of the mounting table 58 is configured as a thin ceramic electrostatic chuck 70 in which a chuck electrode 68 made of a conductive plate such as copper is embedded, and the Coulomb force generated by the electrostatic chuck 70 The wafer W is suction-held on this upper surface. A backside gas such as He gas may be supplied to the surface of the electrostatic chuck 70 to improve the thermal conductivity to the wafer or prevent the film from being formed on the back surface of the wafer. Further, a mechanical clamp may be used instead of the electrostatic chuck 70.
[0018]
An insulated power supply lead wire 72 is connected to the resistance heating element 66, and the lead wire 72 passes through the cylindrical leg portion 60 and the power supply line insertion hole 48 without being exposed to the inside of the processing container 46. And is connected to the power supply unit 76 via the open / close switch 74. Further, an insulated power supply lead wire 78 is connected to the chuck electrode 68 of the electrostatic chuck 70, and the lead wire 78 is also not exposed to the inside of the processing container 46 and is provided inside the cylindrical leg 60 and the power supply line. It is pulled out through the insertion hole 48 and connected to the high-voltage DC power supply 82 via the open / close switch 80. Note that the wafer may be heated by using a heating lamp such as a halogen lamp instead of the resistance heating element 66 as described above.
[0019]
A plurality of lifter holes 84 are provided at predetermined positions in the peripheral portion of the mounting table 58 so as to penetrate vertically, and wafer lifter pins 86 are accommodated in the lifter holes 84 so as to be able to move up and down in the vertical direction. In addition, when the wafer W is loaded and unloaded, the lifter pins 86 are moved up and down by a lifting mechanism (not shown), so that the wafer W is lifted or lowered. Generally, three such wafer lifter pins 86 are provided corresponding to the peripheral portion of the wafer.
[0020]
A ceiling plate 90 integrally provided with a shower head 88 is hermetically attached to the ceiling of the processing container 46 via a sealing member 92 such as an O-ring. And a mounting space 58 is formed between the mounting table 58 and the mounting table 58. The shower head 88 is for introducing a source gas for film formation or the like into the processing container 46 in a shower shape. A large number of injection holes 96 for emitting gas are provided on an injection surface 94 on the lower surface of the shower head 88. It is formed.
[0021]
The inside of the shower head 88 is divided into a head space 88A for the raw material gas and a head space 88B for the alcohol, and the gas introduction port 98 communicated with the head space 88A for the raw material gas is supplied from the vaporizer 26 to the gas introduction port 98. The extending material supply passage 20 is connected to introduce a vaporized metal oxide film material. Further, the alcohol supply passage 42 is connected to the gas introduction port 100 communicating with the alcohol head space 88B so as to introduce the vaporized alcohol. The injection holes 96 are divided into two groups, a source gas injection hole 96A communicating with the source gas head space 88A and an alcohol injection hole 96B communicating with the alcohol head space 88B. The raw material gas jetted from the injection holes 96A and 96B and alcohol are mixed in the processing space S and supplied in a so-called post-mix state. The gas supply method is not limited to the post-mixing method, and the two gases may be mixed in advance in the shower head.
[0022]
Further, on the side wall of the shower head, a cooling jacket 102 for cooling the temperature of this portion to, for example, about 140 to 170 ° C. in order to prevent the decomposition of the raw material gas is provided. , For example, hot water. The distance between the shower head 88 and the mounting table 58 is set to approximately 10 to 30 mm.
[0023]
In addition, a cooling jacket 104 for flowing a coolant, for example, is provided on the side wall of the processing container 46 to cool the wall surface. And is maintained at a temperature at which thermal decomposition does not occur, for example, in the range of 140 to 170 ° C. Further, a part of the side wall of the container 46 is provided with a wafer loading / unloading port 106, in which the gate valve G is provided for communicating with / blocking, for example, a load lock chamber 108 which can be evacuated. . Although not shown, N for purging is used. ₂ Needless to say, gas supply means is provided.
[0024]
Next, the method of the present invention will be described based on an example of the apparatus configured as described above.
First, an unprocessed semiconductor wafer W is loaded from the load lock chamber 108 through the wafer loading / unloading port 106 into the processing chamber 46 maintained in a vacuum state, and the unprocessed semiconductor wafer W is mounted on the mounting table 58 and electrostatically charged. The chuck 70 holds by suction due to the Coulomb force of the chuck 70.
Then, while the wafer W is maintained at the predetermined process temperature by the resistance heating element 66, the inside of the processing chamber 46 is evacuated and the process pressure is maintained at the predetermined process pressure, and the source gas and alcohol are supplied to start film formation. .
[0025]
In the raw material supply means 6, by introducing a pressurized gas such as a He gas whose flow rate is controlled into the raw material tank 12, the liquid Ta (OC ₂ H ₅ ) ₅ Than
The metal oxide film raw material 10 is pressure-fed through the raw material supply passage 20 while its flow rate is controlled by the liquid flow controller 24. At this time, the supply amount of the pressurized gas is, for example, several hundred SCCM, and the supply amount of the liquid raw material is, for example, about several mg / min, which is very small, depending on the film formation rate. Further, since the raw material 10 in the raw material tank 12 is heated by the heater 14 and its viscosity is reduced, the pressure in the supply passage 20 can be relatively smoothly pumped. The pumped liquid raw material is vaporized by a vaporizing gas such as He gas whose flow rate is controlled to, for example, about 200 to 500 SCCM in the vaporizer 26, becomes gaseous, and further flows downstream through the raw material supply passage 20. And is introduced into the shower head 88 of the processing container 46. At this time, since the raw material supply passage 20 on the downstream side is heated by the heat retaining heater 28 to a predetermined temperature, for example, about 130 ° C., the raw material gas is stably prevented from being reliquefied or thermally decomposed. It can flow to the shower head 88. The source gas that has reached the shower head 88 once flows into the source gas head space 88A, and is supplied to the processing space S from the source gas injection holes 96A provided on the injection surface 94.
[0026]
On the other hand, in the alcohol supply means 8, a flow-controlled N 2 is placed in an alcohol tank 34 storing alcohol 32 as an additive. ₂ Gas or O ₂ Gas, etc.
A bling gas is introduced, and alcohol is vaporized by the bubbling of the gas, and flows through the alcohol supply passage 42. At this time, since the alcohol 32 in the alcohol tank 34 is heated by the heater 36, the alcohol 32 can be easily vaporized. The flow rate of the bubbling gas depends on the film formation rate, but is, for example, 1 to 2 liters / min, and the amount of alcohol added is within a range of about 0.1 to 20% based on the metal alkoxide as the raw material. Set to.
The gaseous alcohol flowing in the alcohol supply passage 42 reaches the alcohol head space 88B of the shower head 88, and is supplied to the processing space S from the alcohol injection holes 96B provided on the injection surface 94. Become. In this case, the amount of alcohol to be added can be accurately controlled by the flow controller 40 for controlling the flow of the bubbling gas.
[0027]
The raw material gas and the gaseous alcohol jetted into the processing space S as described above are mixed and reacted in the processing space S, and a tantalum oxide film (Ta) is formed on the wafer surface. ₂ O ₅ ) Is deposited to form a film.
At this time, the film formation reaction is promoted by the direct action of the added alcohol, and water is generated by the decomposition of the alcohol, and the water also promotes the film formation reaction, and as a result, the film formation reaction is greatly increased. It is possible to increase the film formation rate by improving the ratio.
In this case, regardless of the type of alcohol supplied as an additive, not only lower alcohols such as methyl alcohol and ethyl alcohol but also higher alcohols may be used.
[0028]
FIG. 3 is a graph showing the relationship between the process temperature and the film forming rate. The solid line is the curve of the method of the present invention in which alcohol is added, and the wavy line is the curve of the conventional method in which alcohol is not added. The treatment conditions were as follows: the amount of alcohol added to the metal alkoxide was 2%, and ethanol was used as the alcohol. Further, the process pressure was set to 0.2 to 0.3 Torr. As is clear from the graph, in the case of the conventional method indicated by the wavy line, the film formation rate is about 1 nm / min, whereas when the alcohol is added as in the present invention, the film formation rate is 10 nm / min regardless of the process temperature. It shows a high film formation rate before and after, and was able to achieve a film formation rate of about 10 times. The process temperature of the substrate is set in the range of 250 to 450 ° C. If the process temperature is lower than 250 ° C., the film forming rate becomes extremely slow, and there is a disadvantage that sufficient productivity cannot be expected. Conversely, if the process temperature is higher than 450 ° C., the film forming rate becomes too high, Is significantly reduced. Alternatively, the film quality is degraded due to thermal diffusion at the interface between the substrate and the oxide film. Further, since the same film forming speed can be obtained without adding alcohol, the merit of adding alcohol is lost.
[0029]
FIG. 4 is a graph showing the relationship between the amount of alcohol added to the metal alkoxide and the film formation rate. The processing conditions at this time are as follows: the process temperature of the substrate is 400 ° C., and Ta (OC ₂ H ₅ ) ₅ Supply rate of 5 mg / min.
The total flow rate of alcohol was 2000 cc, the process pressure was 0.12 Torr, the film formation time was 60 seconds, and the type of alcohol was ethanol.
As is clear from the graph, as the amount of alcohol added increases, the film formation rate increases. To increase the film formation rate to 3 nm / min or more, which is generally required, 0.1% or more of alcohol is used. It is necessary to add, and when the addition amount is larger than 4.0%, the film formation rate increases, but the film formation rate gradually becomes saturated as shown in FIG. FIG. 5 is a graph showing the film formation rate when the amount of alcohol added is as large as 20% or more. According to this graph, the film formation rate is substantially saturated when the amount of alcohol added is approximately 10%. As a result of examining the film quality, it was found that when the amount of alcohol added was larger than 20%, the uniformity of the film thickness and the film quality were suddenly deteriorated. Therefore, the amount of alcohol to be added is set in the range of 0.1 to 20%.
[0030]
As the bubbling gas, N ₂ An inert gas such as a gas or He gas may be used. ₂ By using gas, the film formation process can be performed with high O ₂ The film formation can be performed under a partial pressure, whereby the film formation rate and the uniformity of the film thickness can be further improved.
Further, since the alcohol supply means 8 and the raw material supply means 6 are separately provided, even if the alcohol is evaporated in an alcohol tank 34 (not shown) or the like, the concentration of the alcohol itself does not change. The ratio can always be controlled with high accuracy and constant, and the film formation rate does not change.
[0031]
In order to add alcohol, here, a supply system for alcohol is provided separately from a supply system for the source gas, and both are so-called post-mixed in the processing vessel. A mixed liquid of a liquid metal oxide film raw material and alcohol is stored in the tank, and the mixed liquid is vaporized by a vaporizer 26 so that the raw material gas and vaporized alcohol are supplied to the apparatus main body 4 in a mixed state. May be. According to this, it is not necessary to provide the alcohol supply means 8 separately, and the structure of the shower head 88 can be simplified. However, the alcohol in the mixed solution evaporates little by little and escapes. , The mixing ratio fluctuates, and thus, although slightly, the film forming rate may fluctuate.
[0032]
As described above, the reason why the deposition rate can be increased by the addition of alcohol is that the deposited Ta ₂ O ₅ This is because it itself acts as a catalyst for alcohol, promoting the decomposition of alcohol and assisting the generation of water.
Further, here, the case of forming tantalum oxide as a metal oxide film has been described as an example, but the present invention is not limited to this, and other metal oxide films such as titanium oxide, zirconium oxide, barium oxide, and strontium oxide are formed. In this case, the raw materials use metal alkoxides of these metals. Further, the present invention can be applied to the case of forming niobium oxide, hafnium oxide, yttrium oxide, lead oxide, etc. other than the above-mentioned metal oxide film. That is, since these metal oxides themselves function as an alcohol decomposition catalyst, the film formation rate can be improved.
[0033]
Since the film itself formed in this way promotes the decomposition of alcohol and can improve the film formation rate, when forming a film using metal alkoxide as a raw material, it is necessary to separately install an alcohol decomposition catalyst in the processing vessel. The film rate can be further improved.
FIG. 6 is a configuration diagram illustrating an example of such a film forming apparatus, and FIG. 7 is a plan view illustrating a shape of an alcohol decomposition catalyst used in the film forming apparatus.
[0034]
Here, the same parts as those of the apparatus configuration shown in FIG. 1 are denoted by the same reference numerals.
As shown in the drawing, in this film forming apparatus, an alcohol decomposition catalyst 110 is disposed between the lower surface of the shower head 88 and the mounting table 58 to actively promote the decomposition of alcohol and to assist in the generation of moisture. Make up.
Specifically, as shown in FIG. 7, the alcohol decomposition catalyst 110 is formed by stretching a wire 114 in a lattice shape or a mesh shape in a ring-shaped support ring 112 that is slightly larger than the diameter of the wafer W. It is composed. The support ring 112 is fixed to, for example, the lower surface of the shower head 88 via a support rod 116 so as not to hinder the injection of the raw material gas or alcohol.
With this configuration, when the alcohol passes between the wires 110 composed of the alcohol decomposition catalyst 110, the alcohol is brought into contact with the catalyst to promote the decomposition of the alcohol, and more water is generated. Rate can be improved.
[0035]
As such an alcohol decomposition catalyst 110, in addition to a metal oxide such as a tantalum oxide, titanium oxide, zirconium oxide, strontium oxide, niobium oxide, hafnium oxide, yttrium oxide, lead oxide, and the like can be used. Other metal oxides include W ₂ O ₅ , Mo ₂ O ₅ , Fe ₂ O ₃ , ThO ₃ , Al ₂ O ₃ , V ₂ O ₅ , CdO, VO ₂ , Cr ₂ O ₃ , MnO, BeO, SiO ₂ , MgO or the like can also be used as a catalyst.
Furthermore, SiO-Al ₂ O ₃ Or a composite oxide such as platinum, or a nitride such as TiN, AlN or TaN can also be used as a catalyst.
[0036]
Here, the alcohol decomposition catalyst is provided between the mounting table 58 and the shower head 88. However, the present invention is not limited to this. For example, the alcohol decomposition catalyst may be placed on the inner surface of the shower head 88 in contact with the alcohol. A coating may be provided, or an alcohol decomposition catalyst formed into, for example, a ring shape may be provided on the outer peripheral side of the mounting table 58.
In the above embodiment, a case where a film is formed on a semiconductor wafer as an object to be processed has been described as an example. However, the present invention is not limited to this.
[0037]
【The invention's effect】
As described above, according to the film forming method and the apparatus of the present invention, the following excellent operational effects can be exhibited.
When forming the metal oxide film, an alcohol supply means is provided, and alcohol is added to the metal oxide film raw material to cause a reaction, so that the film formation rate of the metal oxide film can be significantly improved, and therefore, Throughput can also be improved.
Further, in the case where the metal oxide film raw material and the alcohol are preliminarily mixed to form a mixed liquid, and the mixed liquid is vaporized and supplied, it is not necessary to provide an alcohol supply means. The effect can be exhibited.
[Brief description of the drawings]
FIG. 1 is a schematic overall configuration diagram showing a film forming apparatus according to the present invention.
FIG. 2 is a configuration diagram showing a main body of a film forming apparatus.
FIG. 3 is a diagram showing a relationship between a process temperature and a film formation rate.
FIG. 4 is a graph showing the relationship between the amount of alcohol added to a metal alkoxide and the film formation rate.
FIG. 5 is a diagram showing a relationship between an alcohol addition amount and a film formation rate.
FIG. 6 is a configuration diagram showing a main body of another film forming apparatus of the present invention.
FIG. 7 is a plan view showing a shape of an alcohol cracking catalyst used in the apparatus shown in FIG.
[Explanation of symbols]
2 Film forming equipment
4 Main unit
6 Raw material supply means
8 alcohol supply means
10 Metal alkoxide (metal oxide film raw material)
12 Raw material tank
20 Raw material supply passage
24 Liquid flow controller
26 vaporizer
32 Additives (alcohol)
34 alcohol tank
42 Alcohol supply passage
46 Processing container
54 Evacuation system
58 Mounting table
66 Resistance heating element
70 Electrostatic chuck
88 shower head
88A Head space for source gas
88B Alcohol head space
96 injection holes
96A Injection hole for source gas
96B Alcohol injection hole
110 alcohol decomposition catalyst
W Semiconductor wafer (workpiece)

Claims (13)

In a film forming apparatus for forming a metal oxide film on an object to be processed, a processing container which can be evacuated, a mounting table for mounting an object to be processed contained in the processing container, and vaporization in the processing container A raw material supply unit for supplying a metal oxide film raw material in a state, an alcohol supply unit for supplying a vaporized alcohol into the processing container, a vacuum exhaust system for evacuating the processing container, and promoting the decomposition of the alcohol And a catalyst for decomposing alcohol. The film forming apparatus according to claim 1, wherein the metal oxide film material is a metal alkoxide. The method according to claim 1, wherein the metal oxide film includes one of tantalum oxide, titanium oxide, zirconium oxide, barium oxide, strontium oxide, hafnium oxide, niobium oxide, yttrium oxide, and lead oxide. 3. The film forming apparatus according to 2. The film forming apparatus according to any one of claims 1 to 3, wherein the alcohol decomposition catalyst is disposed above the mounting table. 5. The film forming apparatus according to claim 1, wherein the alcohol decomposition catalyst is made of a metal oxide. The film forming apparatus according to claim 1, further comprising a shower head for introducing the alcohol and the metal oxide film raw material into the processing container. In a method of forming a metal oxide film on a surface of an object to be processed in a vacuum-treated processing container, the alcohol decomposition catalyst is accelerated by an alcohol decomposition catalyst in a vacuum atmosphere containing a metal oxide film raw material and alcohol. A film forming method for forming the metal oxide film while forming the metal oxide film. 8. The film forming method according to claim 7, wherein the metal oxide film raw material and the alcohol are introduced into the processing vessel by separate supply systems after being vaporized . 9. The film forming method according to claim 7, wherein a processing temperature of the object is set in a range of 250 to 450 [deg.] C. 10. The film forming method according to claim 7, wherein the amount of the alcohol added is set in a range of 0.1 to 20% with respect to the metal oxide film raw material. 11. The film forming method according to claim 7, wherein the metal oxide film material is a metal alkoxide. The metal oxide film includes any one of tantalum oxide, titanium oxide, zirconium oxide, barium oxide, strontium oxide, hafnium oxide, niobium oxide, yttrium oxide, and lead oxide. 12. The film forming method according to any one of 11. 13. The film forming method according to claim 7, wherein the metal oxide film itself has an alcohol decomposition catalyst function of accelerating the decomposition of alcohol.

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