JPH1079380A - Modification method and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modification device capable of enhancing the isolation voltage of a metallic oxide film in a short time. SOLUTION: The modification device 2 for a metallic oxide film enhancing the metallic oxide film formed on the surface of a body to be treated W is constituted so as to have a treating vessel 4 capable of being evacuated, a base 14, on which the body to be treated housed in the treating vessel is placed, a treating-gas supply means 47 supplying the inside of the above-mentioned treating vessel with a treating gas containing ozone or N1 O gas, an ultraviolet irradiating means 62 irradiating the inside of an atmosphere in the above- mentioned treating vessel with ultraviolet rays and generating active oxygen atoms, and an evacuation system 12 evacuating the inside of the above- mentioned treating vessel. Accordingly, active oxyen atoms are generated tmder a vacuum atmosphere, density is also increased by lengthening the lifetime of the oxygen atoms, and quick modification treatment is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for modifying an insulating film such as tantalum oxide.

[0002]

2. Description of the Related Art In general, in order to manufacture a semiconductor device, a film forming process and a pattern etching process are repeatedly performed on a semiconductor wafer to manufacture a desired device. With the increase in integration, the specifications have become stricter year by year.For example, even thinner oxide films such as capacitor insulating films and gate insulating films in devices have been required to be further thinned. At the same time, higher insulating properties are required.

As these insulating films, a silicon oxide film, a silicon nitride film or the like can be used.
Recently, a metal oxide film such as tantalum oxide (Ta ₂ O ₅ ) has tended to be used as a material having better insulating properties. Although this metal oxide film exhibits a highly reliable insulating property even if it is thin, it is possible to further improve the insulating property by performing a surface modification treatment after forming the metal oxide film. Discovered,
Japanese Patent No. 283022 discloses the technique.

In order to form this metal oxide film, for example, a case of forming tantalum oxide will be described. As disclosed in the above-mentioned publication, a metal alkoxide of tantalum (Ta (OC (OC)) is used as a raw material for film formation. ₂ H ₅ ) ₅ ) is supplied while bubbling with a nitrogen gas or the like to maintain the semiconductor wafer at a process temperature of, for example, about 400 ° C., and to perform CVD (Chemical Va) under a vacuum atmosphere.
A tantalum oxide film (Ta ₂ O ₅ ) is laminated by por deposition. In order to further improve the insulation properties as needed, this semiconductor wafer is carried into an atmosphere containing ozone, and irradiated with ultraviolet rays from a mercury lamp under atmospheric pressure to activate oxygen atoms. Is generated, and the tantalum oxide film is modified by using the active oxygen atoms, thereby obtaining an insulating film having better characteristics.

[0005]

As described above, it is important to improve the characteristics of the insulating film. At the same time, however, the productivity, that is, the throughput, is increased in order to manufacture a large number of devices of good quality. Need to be large. However, the film formation step and the modification 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, taking the reforming process as an example, depending on the amount of ultraviolet rays and ozone, in order to obtain a withstand voltage that can withstand use, a single wafer is usually subjected to a reforming process for about 30 minutes. However, there is a problem that the throughput is not sufficient and the cost is high. The present invention has been devised in view of the above problems and effectively solving them. SUMMARY OF THE INVENTION An object of the present invention is to provide a reforming method and apparatus capable of improving the dielectric strength of a metal oxide film in a short time.

[0006]

Means for Solving the Problems As a result of intensive studies on the reforming conditions, the present inventor has conducted the reforming treatment not in the atmosphere but in the air.
The present invention has been made based on the finding that the modification can be performed in a short time by performing in a vacuum. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a metal oxide film reforming apparatus for reforming a metal oxide film formed on the surface of an object to be processed. A mounting table for mounting an object to be processed housed in a container, processing gas supply means for supplying a processing gas containing ozone or N ₂ O gas into the processing container,
An ultraviolet irradiation means for irradiating ultraviolet rays into the atmosphere in the processing vessel to generate active oxygen atoms, and a vacuum exhaust system for evacuating the inside of the processing vessel are provided.

A metal oxide film such as tantalum oxide is previously formed on the surface of the object to be processed in a previous step, and such an object is placed and held on a mounting table in a processing vessel to be modified. Quality treatment. The inside of the processing vessel is maintained under a predetermined vacuum pressure by a vacuum evacuation system, and the ozone or N ₂ O gas supplied from the processing gas supply means is irradiated with ultraviolet rays radiated from the ultraviolet irradiation means. Is generated. In this case, since the inside of the processing container is in a vacuum state, the time until the generated active oxygen atoms disappear becomes longer and the concentration becomes higher, and as a result, the reforming process can be performed quickly. .

In this case, the pressure during the reforming process is 1 to
It is preferable to set the pressure within the range of 600 Torr. Outside this range, the reforming treatment is not sufficient, and the withstand voltage of the metal oxide film decreases. Further, the temperature of the object during the reforming process is desirably within a range of 320 to 700 ° C., 300 to 350 ° C. at atmospheric pressure, and 10 To under atmospheric pressure.
350-450 ° C at rr and 400 ° C at 10 Torr or less
There is an effect within the above range up to 700 ° C. However, by improving the degree of vacuum, a good reforming effect up to 700 ° C. can be obtained. At this time, since the chamber walls are water-cooled and the decomposition of ozone mainly occurs on the substrate surface, the reforming effect is not reduced due to the decomposition of ozone.
As the ultraviolet irradiation means, those having various structures can be used. For example, ultraviolet rays are generated by applying microwaves generated from microwave generation means to a mercury-filled lamp filled with mercury, and the ultraviolet rays are reflected by a reflecting mirror. And then irradiating the processing gas with light to generate active oxygen atoms. Further, as another structure, a plurality of cylindrical ultraviolet lamps may be arranged in parallel.

Further, in order to generate active oxygen atoms,
Instead of using ultraviolet light, plasma may be used. For example, active oxygen atoms may be generated by applying a microwave or a high-frequency electric field to a processing gas containing at least one of O ₂ gas, ozone and N ₂ O gas. Further, as another example of the apparatus, as the shower head of the processing gas supply means, a shower head configured by combining a plurality of gas injection pipes having a large number of injection holes, for example, in a lattice shape may be used. In this case, since the gas injection tubes are arranged in a lattice, a large amount of ultraviolet light is directly irradiated to the object without passing through the quartz shower head. Therefore, ultraviolet rays are not so much absorbed by ozone and the like in the shower head, and the reforming efficiency can be improved. In this case, it is preferable that the projection area of the gas injection tube on the mounting table is set to be smaller than 20% of the area of the surface of the object to be processed.

As another example of the apparatus, as a part of the processing gas supply means, a container-like lid having an open lower end so as to cover the object to be processed is provided, and an injection is provided on one side thereof. An introduction header portion having a hole is formed, and a discharge header portion having a discharge port on the other side is formed. Then, at the time of reforming, a gas flow that flows in the horizontal direction is formed in the lid while the target object is covered from above. According to this, since active oxygen atoms can be generated at a high concentration near the surface of the object to be treated, the reforming efficiency can be greatly improved. Further, in order to enable loading and unloading of the object to be processed, the lid and the mounting table are relatively close to each other in a vertical direction.

Further, as another example of the apparatus, there is provided a processing container capable of being evacuated in a metal oxide film reforming apparatus for reforming a metal oxide film formed on the surface of a processing object; A mounting table for mounting the processing object accommodated therein, processing gas supply means for supplying a processing gas containing ozone or N ₂ O gas into the processing container, and heating for heating the processing object Means, and a vacuum evacuation system for evacuating the inside of the processing vessel, wherein the heating means heats the object to be processed within a range of 400 ° C to 850 ° C. According to this, it is possible to perform reforming by maintaining the target object at a predetermined temperature while supplying ozone or N ₂ O gas without irradiating ultraviolet rays.

In this case, the reforming process temperature is 400 ° C.
~ 850 ° C, especially 450 ° C ~ 500 ° C
Is preferable. As a heating means in this case, for example, it is preferable to heat from below the mounting table using a heating lamp. Further, in order to suppress the decomposition of ozone due to the gas phase reaction near the side wall of the processing container, it is preferable to provide a cooling jacket on the side wall of the processing container and cool this temperature to a temperature lower than the thermal decomposition temperature of ozone. As a metal oxide film to be modified, tantalum oxide, titanium oxide, zirconium oxide, barium oxide, strontium oxide, or the like can be used.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the reforming method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a configuration diagram showing a reforming apparatus according to the present invention. Here, a case where a semiconductor wafer is used as an object to be processed and a metal oxide film of tantalum oxide (Ta ₂ O ₅ ) formed on the surface is modified will be described as an example.

As shown in the figure, the reforming apparatus 2 has a processing container 4 formed into a cylindrical shape by, for example, aluminum. In the periphery of the bottom 4A of the processing container 4,
A plurality of exhaust ports 6 are provided, and the exhaust ports 6
A vacuum pump, for example, a vacuum evacuation system 12 provided with a turbo molecular pump 8 and a dry pump 10 interposed therebetween is connected, and the inside of the container can be evacuated. In the processing container 4,
Disc-shaped mounting table 14 made of a non-conductive material, for example, alumina
The center of the lower surface of the mounting table 14 is
A is supported and fixed at the tip of a hollow rotary shaft 16 provided vertically through A. A magnetic fluid seal 18 is provided in a portion of the rotary shaft 16 penetrating the bottom of the container. The magnetic fluid seal 18 is supported in an airtight and rotatable manner so that the mounting table 14 can be rotated as required. ing. In addition, this rotating shaft 16
Are rotatable by a driving force from a rotary motor (not shown) or the like.

The mounting table 14 has embedded therein, for example, a resistance heating element 20 made of carbon coated with SiC as a mounting table heating means, and a semiconductor wafer as a processing object mounted on the upper surface side thereof. W can be heated to a desired temperature. An upper portion of the mounting table 14 has a chuck electrode 22 made of a conductive plate such as copper inside.
Is embedded as a thin ceramic electrostatic chuck 24, and the wafer W is sucked and held on the upper surface by the Coulomb force generated by the electrostatic chuck 24. A backside gas such as He gas may be flowed over the surface of the electrostatic chuck 24 to improve the thermal conductivity to the wafer. An insulated power supply lead wire 26 is connected to the resistance heating element 20, and the lead wire 26 is drawn out through the hollow rotary shaft 16 without being exposed to the inside of the processing container 4. It is connected to the power supply unit 30 via the open / close switch 28. Further, an insulated power supply lead wire 32 is connected to the chuck electrode 22 of the electrostatic chuck 24, and this lead wire 32 also passes through the hollow rotary shaft 16 without being exposed to the inside of the processing container 4. It is pulled out and connected to a high-voltage DC power supply 36 via an open / close switch 34. The wafer may be heated by using a heating lamp such as a halogen lamp instead of the resistance heating element 20.

A plurality of lifter holes 38 are provided in a predetermined position in the peripheral portion of the mounting table 14 so as to penetrate in the vertical direction. The wafer lifter pins are vertically movable in correspondence with the lifter holes 38. 40 are arranged. The wafer lifter pin 40 can be integrally moved up and down by a pin elevating rod 41 which is vertically movable through the container bottom 4A. Also, this rod 41
A metal telescopic bellows 42 is provided in the penetrating portion of the rod, and allows the rod 41 to move up and down while maintaining airtightness. By raising and lowering the pins 40 in this manner, the wafer W is lifted or lowered. Such a wafer lifter pin 40 is
Generally, three are provided corresponding to the peripheral portion of the wafer.

A thin container-shaped shower head 44 made of a heat-resistant material that is transparent to ultraviolet rays, for example, fused quartz, which will be described later, is provided on the ceiling of the processing container 4.
On the lower surface, a number of injection holes 46 for jetting the processing gas introduced into the head 44 toward the processing space S are provided. The gas inlet 48 of the shower head 44 passes through the side wall of the container in an airtight manner and faces the outside, and is connected to a gas inlet pipe 58 of the processing gas supply means 47. A known ozone generator 52 is connected to the gas introduction pipe 58 via a mass flow controller 50, and the generated ozone is sent to the shower head 44 as a processing gas. In order to generate ozone, not only oxygen gas but also a small amount of an additional gas for improving generation efficiency, for example, N ₂ gas or a mixed gas of N ₂ gas and H ₂ gas is added to the ozone generator 52. It has become. Incidentally, N ₂ O gas may be used instead of ozone as the processing gas. The distance L1 between the shower head 44 and the mounting table 14 is set to about 50 mm in order to secure a space for loading and unloading wafers. At the time of processing, the distance can be made closer to the vicinity of the shower head by raising and lowering the wafer position. At this time, the distance is variable within a range of 1 to 50 mm.

On the other hand, a circular opening 54 which is set to be larger than the diameter of the wafer is formed in the ceiling of the processing container 4, and this opening is formed of a material transparent to ultraviolet rays, for example, quartz. A circular transmission window 56 is hermetically attached to the ceiling by a fixed frame 60 via a sealing member 59 such as an O-ring. The thickness of the transmission window 56 is set to, for example, about 20 mm so as to withstand the atmospheric pressure. Then, above the transmission window 56,
Ultraviolet irradiation means 62 for radiating ultraviolet UV toward the inside of the processing container 4 is provided, and active ultraviolet atoms are generated by the ultraviolet UV emitted from the ultraviolet irradiation means 62. Specifically, the ultraviolet irradiation means 62 includes a substantially spherical mercury-filled lamp 64 filled with mercury, a microwave generation means 66 for generating a microwave for irradiating the lamp 64, and an upper side of the lamp 64. Covered processing container 4
It is mainly constituted by a reflecting mirror 68 that reflects ultraviolet rays toward the inside.

The microwave generating means 66 generates, for example, a microwave of 2.45 GHz, and the microwave generating means 66 is connected to the mercury-filled lamp 64 by a waveguide 70. This waveguide 70
, And irradiates the lamp 64 to generate ultraviolet light. The mercury-filled lamp 64 can generate a large amount of ultraviolet light by introducing a large electric power, unlike a normal cold cathode tube that generates ultraviolet light. The reflecting mirror 68 is formed, for example, by forming an aluminum plate into a dome shape, and the curvature is set so that the reflected light of the ultraviolet light is substantially uniformly reflected on the surface of the mounting table 14. It should be noted that, in place of the mercury-filled lamp 64, the active oxygen atom generation efficiency is 180 nm.
An excimer lamp that emits a large amount of ultraviolet light having the following wavelengths may be used.

In addition, a cooling jacket 72 for flowing a coolant, for example, for cooling the wall surface is provided on a side wall of the processing container 4, and cold water of, for example, about 20 ° C. is made to flow as a coolant. A part of the side wall of the container is provided with a wafer transfer port 74, and a gate valve G is provided in the part of the side wall of the container for opening / closing the load lock chamber 76, for example. Although not shown, it is needless to say that a means for supplying N ₂ gas for purging is provided, and the same applies to each processing container described below.

Next, the method of the present invention will be described based on an example of the apparatus configured as described above. Before the reforming process is performed using the apparatus according to the present invention, a metal oxide film such as tantalum oxide is formed on the surface of the semiconductor wafer in a previous step. This metal oxide film is used, for example, as a capacitance of an integrated circuit or a gate insulating film.
First, the unprocessed semiconductor wafer W on which the metal oxide film is formed as described above is placed in the processing container 4 maintained in a vacuum state.
The wafer is introduced from the load lock chamber 76 through the wafer loading / unloading port 74, is placed on the mounting table 14, and is suction-held by the Coulomb force of the electrostatic chuck 24. The reforming process is started by supplying ozone as a processing gas while maintaining the wafer W at a predetermined process temperature by the resistance heating element 20 and evacuating the processing chamber 4 to maintain a predetermined process pressure. I do. At this time, the wafer position is set to a predetermined position by the vertical mechanism.

The ozone generator 52 of the processing gas supply means 47
Ozone (O ₃ ) is generated by supplying a small amount of, for example, N ₂ gas as oxygen and an additional gas, and a mixed gas of ozone, oxygen and N ₂ gas mainly composed of ozone is used as a processing gas. The gas is introduced into the shower head 44 through the gas introduction pipe 58 while controlling the flow rate, and the number of the injection holes 4 is increased.
6 is ejected toward the processing space S. The reason for adding a small amount of additional gas is to increase the ozone generation efficiency of the ozone generator 52 as described above.

On the other hand, at the same time, the ultraviolet irradiation means 62
A microwave of 2.45 GHz is generated from the microwave generating means 66 of this embodiment.
After being propagated through the lamp, the light is irradiated toward the mercury-filled lamp 64. A large amount of ultraviolet rays UV is emitted from the mercury-filled lamp 64 by this microwave irradiation.
V is directly or after being reflected by a dome-shaped reflecting mirror 68, passes through a quartz transmission window 56 and enters the processing vessel 4 maintained at a predetermined vacuum pressure. The permeate is poured into the processing gas containing ozone as a main component in the processing space S. The pressure in the shower head is higher than that in the processing chamber, but is in a reduced pressure state.

Here, the ozone is excited by the irradiation of ultraviolet rays to generate a large amount of active oxygen atoms 78, and the active oxygen atoms 78 act on the metal oxide film formed on the surface of the wafer to substantially reduce this. It will be completely oxidized and reformed. In this case, since the processing vessel 4 is maintained in a vacuum state, the probability that the generated active oxygen atoms 78 collide with other gas atoms or gas molecules is extremely reduced,
As a result, the density of the active oxygen atoms 78 is improved as compared with the case where the treatment is performed under the atmospheric pressure as in the conventional apparatus, and the reforming treatment can be performed quickly. By this reforming process, the insulating property of the metal oxide film can be rapidly and significantly improved.

The dome-shaped reflecting mirror 6 of the ultraviolet irradiation means 62
8 is set to an appropriate curvature so that the reflected light from here on is distributed substantially evenly on the surface of the mounting table 14.
The generated ultraviolet rays UV can be used for generating the active oxygen atoms 78 without waste. During the reforming process, the mounting table 14 supported by the rotating shaft 16 rotates the wafer W mounted thereon integrally, so that
It is possible to eliminate the occurrence of unevenness in reforming on the wafer surface, and it is possible to substantially uniformly reform the front surface of the metal oxide film.

During the reforming, the pressure in the vessel is from 1 to 600
Set within the range of Torr. For pressures outside this range,
The progress of the reforming is slow or insufficient, and the withstand voltage of the metal oxide film is reduced. Further, the wafer temperature during the reforming process is set within a range of 320 to 700 ° C. If the wafer temperature is lower than 320 ° C., the withstand voltage is not sufficient, and if the wafer temperature is higher than 700 ° C., the oxidizing substance is crystallized, so that the effect of reforming is lost.

The mercury-filled lamp 64 used here can emit a large amount of ultraviolet rays mainly having wavelengths of 185 nm and 254 nm, which can contribute to the activation of the gas, because a large amount of electric power can be supplied. Can be achieved. If an excimer lamp that emits a large amount of ultraviolet light having a wavelength of 180 nm or less, which can further contribute to the activation of the gas, is used instead of the lamp 64, the reforming can be expected to be further speeded up. The additive gas is not limited to the N ₂ gas described above, and may be a mixed gas of N ₂ gas and H ₂ gas. Further, even if the processing gas supplied to the shower head 44 is supplied with N ₂ O gas instead of ozone, exactly the same operation and effect can be produced. Here, known experimental results regarding the reforming will be described in detail with reference to graphs. FIG. 2 is a graph showing the relationship between irradiation time and insulation characteristics (leakage current) when irradiating ultraviolet rays in an ozone atmosphere.
60 Torr. Here, a metal oxide film is used as a gate insulating film.

According to this, the reforming time is changed from 0 minutes to 10 minutes.
And 60 minutes, the leakage current is reduced and the breakdown voltage with respect to the applied gate voltage is gradually increased.
This indicates that the characteristics are gradually improved. Therefore, it is proved that the modification treatment by irradiation with ultraviolet light in the presence of ozone is very effective. FIG. 3A is a graph showing the relationship between the reforming process pressure and the withstand voltage by the irradiation of ultraviolet light in the presence of ozone.
Minutes. In the figure, the process pressure is 1.
In the range of 0 to 600 Torr, the dielectric strength exceeds the standard withstand voltage of 2.0 V, showing good characteristics.
5.0-200To around a pressure of 0.0Torr
It turns out that the characteristics within the range of about rr are the best. Note that, in the figure, the dashed line indicates the characteristics in the case where no reforming treatment is performed. As a result, the reforming can be performed in a shorter time under vacuum as compared with the processing at atmospheric pressure.
Further, in the atmospheric pressure treatment, the distance between the shower head and the wafer must be shortened so that the generated active oxygen must reach the wafer surface even if its life is short. However, in a vacuum, even if the distance between the shower head and the wafer is increased, an effect equivalent to the atmospheric pressure can be obtained. The reason for this is that the active oxygen atoms generated in vacuum have a longer lifetime,
This is because a sufficient amount of active oxygen atoms is supplied to the wafer surface.

FIG. 3B shows the results when the tantalum oxide film was modified with ultraviolet rays under reduced pressure.
It shows the case of the 3-minute process and the case of the 10-minute process, and also shows the results of the process under the atmospheric pressure for 10 minutes and 60 minutes. The processing conditions are a temperature of 400 ° C. and a pressure of 1 Torr. As is clear from the graph, at atmospheric pressure 60
The characteristics when treated for 10 minutes show almost the same characteristic curves as those of the present invention treated for 10 minutes under reduced pressure.
Compared with the conventional atmospheric pressure treatment, according to the present invention, about 1/6
The same effect as that of the related art can be obtained by the short processing.

In the above-described embodiment, a mercury-filled lamp that emits ultraviolet rays by irradiating microwaves is used as the ultraviolet irradiating means. Instead of this, a normal ultraviolet lamp that emits ultraviolet rays without using microwaves is used. May be used. FIG. 6 is a configuration diagram showing such a reforming apparatus, and the same components as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. That is, in this configuration, the ultraviolet irradiation means 62 has a plurality of cylindrical ultraviolet lamps 80, and here, seven ultraviolet lamps 80 are placed outside the quartz transmission window 56 on the mounting table 14. Are arranged so as to be in parallel with each other. The number of lamps 80 is merely an example, and may be increased as needed to obtain the required UV intensity. As such an ultraviolet lamp, for example, a cold cathode tube capable of emitting a large amount of ultraviolet light with a small power of about 20 W can be used. The shape of the ultraviolet lamp 80 is as follows.
The lamp is not limited to a cylindrical straight tube shape, and a lamp obtained by bending and deforming this into a U-shape, a W-shape, or a meandering shape can also be used.

The entirety of the plurality of ultraviolet lamps 80 is covered by a box-shaped casing 82, and a reflecting mirror 84 for reflecting ultraviolet light upward from the lamps downward is provided inside the casing 82. ing. The device configured in this manner also exerts the same function and effect as the device shown in FIG. 1, and the ultraviolet rays UV emitted from the ultraviolet lamp 80
When the light passes through the transmission window 56 and the shower head 44 and irradiates the processing space S, the processing gas such as ozone present therein is activated to generate active oxygen atoms 78. And
The active oxygen atoms 78 act on a metal oxide film formed on the surface of the semiconductor wafer W to completely oxidize the metal oxide film,
It will be reformed. In particular, in this embodiment, since no microwave generating means is used as compared with the apparatus shown in FIG. 1, the structure can be simplified and the cost can be reduced accordingly.

In the structure shown in FIGS. 1 and 6,
The shower head 44 has a structure for introducing ozone into a disk-shaped container. However, when the pressure of ozone in the shower head 44 is high to some extent,
Ultraviolet rays UV are absorbed by ozone in the shower head 44 and cannot sufficiently reach the wafer surface, or the probability that active oxygen atoms generated in the shower head 44 reach the wafer surface without disappearing decreases. In some cases. Therefore, as shown in FIGS. 7 and 8, the shower head may be constituted by a plurality of gas injection tubes arranged in a grid, for example. FIG. 7 is a structural view showing a main part of a third embodiment of the reformer of the present invention, and FIG. 8 is a bottom view showing a shower head of the apparatus shown in FIG. In the illustrated example, the same parts as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted. Also, in this illustrated example, only the main part is described, and other parts other than the parts described here are formed in the same manner as the configuration shown in FIG. 1 or FIG.

As shown in FIG.
For example, a low-pressure mercury lamp is used as 0, and for example, 90% of ultraviolet light having a wavelength of 254 nm generated thereby is used.
The lamp 80 is provided above the transmission window 56 for transmitting the above. A shower head 44 made of quartz that transmits at least 90% of ultraviolet rays is provided just below the transmission window 56 in the same manner as the material of the transmission window 56. Specifically, the shower head 44 is a ring-shaped distribution ring tube 1 having a diameter larger than the diameter of the wafer W.
10 and a plurality of gas injection tubes 112 arranged and connected between the distribution ring tubes 110 in a vertical and horizontal grid. The inner diameters of the ring tube 110 and the gas injection tube 112 are about 16 mm and 4.35 mm, respectively, and the lower surface of each gas injection tube has a diameter of, for example, 0.3 to 0.5 m.
A large number of injection holes 46 of about m are formed at an equal pitch so that an ozone-containing processing gas can be injected.

In this case, the mounting table 1 of each gas injection tube 112
The projection area of the wafer W on the wafer 4 is preferably set to be smaller than 20% of the area of the wafer surface. The surface is illuminated. In the case of the above configuration, the ozone-containing processing gas introduced into the shower head 44 first wraps around the ring-shaped distribution ring tube 110 and flows into each gas injection tube 112. Then, this processing gas is supplied into the processing container 4 from the many injection holes 46 provided in the gas injection pipe 112, so that the ozone gas can be uniformly supplied to the wafer surface.

[00035]
A space 114 is provided between the grid-shaped gas injection pipes 112.
Since many UV rays pass through the space 114, many UV rays directly irradiate the wafer surface without interfering with the ozone in the shower head 44. The amount of active species on the surface increases accordingly, and the modification can be performed more efficiently. In particular, by setting the projection area of each gas injection tube 112 to be smaller than 20% of the wafer surface, that is, by setting the opening ratio, which is the area ratio of the space portion 114, to 80% or more, it is possible to perform a good reforming process and improve the characteristics. A good insulating film or the like can be obtained. At the time of reforming, the mounting table 1
By rotating 4, a uniform reforming process can be performed over the wafer surface. FIG. 9 is a graph showing the relationship between the aperture ratio (100-% of projected area) of the gas injection tube and the withstand voltage. At this time, the film thickness of Ta ₂ O ₅ was 10 nm, and as is clear from the graph, the aperture ratio was 80% or less (the projected area was 20%).
%), The withstand voltage becomes 1.8 volts or more, which indicates that a high-quality insulating film can be formed. Further, when the processing was performed at an ozone concentration of 150 g / m ³ at a wafer temperature of 400 ° C. and a processing pressure of 1 Torr, the current-voltage characteristics of the 10-minute processing under reduced pressure shown in FIG. It took only 5 minutes or less to obtain, and the processing could be performed efficiently. Furthermore, even when such a treatment was performed at a degree of vacuum in the range of 1 to 500 Torr, a similar remarkable effect of improving the film quality could be obtained.

Here, the case where a plurality of gas injection tubes 112 are assembled in a lattice shape has been described as an example. However, if a space 114 having a certain width can be ensured, the shape and arrangement of these gas injection tubes 112 will be described. There is no limitation, for example, they may be arranged linearly and in parallel, or may be arranged concentrically or spirally. 7 and 8 in the above-described embodiment.
In the structure shown in FIG. 1, ozone is supplied to the whole area in the processing container, but ozone may be supplied locally as shown in FIGS. FIG. 10 is a configuration diagram showing a main part of a fourth embodiment of the present invention, FIG. 11 is a diagram showing a state where a mounting table of the apparatus shown in FIG.
2 is a sectional view showing a shower head of the apparatus shown in FIG.

In the illustrated example, the same parts as those in the previous embodiment are denoted by the same reference numerals, and the description is omitted. Also, in this illustrated example, only the main part is described, and other parts other than the part described here are described with reference to FIGS.
It is formed similarly to the configuration shown in FIG. As shown in the figure, the shower head 44 has a circular container-shaped lid 116 whose lower end is opened so that the upper surface of the mounting table 14 can be covered. This lid 116 is
Is set slightly larger than the diameter of the mounting table 14 and the whole is made of ultraviolet-permeable quartz. On one side of the lid 116, an introduction header 118 having a large number of injection holes 46 directed in the lateral direction is formed in an arc shape, and the gas introduction pipe 58 is connected to this. On the other side of the lid 116, a discharge header section 122 having a discharge port 120 is provided so that a gas flow flowing in the horizontal direction can be formed in the lid 116. The outlet 120 has a slit shape formed in an arc shape along the circumferential direction of the lid 116 so as to form a uniform horizontal gas flow as described above. Further, an opening 124 opened into the processing container 4 is formed on the outer periphery of the discharge header section 122.

In order to carry in / out the wafer, the mounting table 14 can be moved up and down by a small distance while maintaining a vacuum in the processing container by an elevating mechanism (not shown). 116 can be approached and separated. FIG. 11 shows a state where the mounting table 14 is lowered. In order to maintain a vacuum in the processing container 4, for example, a bellows 126 is provided around the mounting table 14.
Note that, instead of the mounting table 14, the lid 116 may be movable up and down. In this embodiment, in the state shown in FIG. 10, the ozone-containing processing gas introduced into the introduction header portion 118 is supplied to the cover 116 from the injection hole 46 provided here.
And the gas flows in the horizontal direction into the discharge header 112 on the opposite side. The gas that has flowed into the processing container 4 that has been evacuated,
4 would flow out.

In this case, active oxygen atoms can be generated at a high concentration in a narrow space within the lid 116 and near the wafer surface, so that the reforming process can be performed efficiently. Instead, a modified film having better characteristics can be obtained. The lower end of the lid body 116 is placed in contact with the upper surface periphery of the mounting table 14 or in a state in which the lower end portion is very close without contact. Also in this case, if the mounting table 14 is rotated at the time of the reforming, the reforming process in the wafer surface can be made more uniform. The mounting table 14
Is divided into a peripheral portion and a central portion, and a ring-shaped peripheral portion that abuts on the lid body 116 is formed as a ring-shaped fixed mounting table, so that the lower end of the lid body 116 is fixedly mounted while rotating the wafer W. The processing can be performed in a state in contact with the mounting table.
Since gas leakage from other sources can be suppressed, the active oxygen concentration in the lid 116 can be further improved.

With such a configuration, a remarkable effect of improving the film quality could be obtained when the degree of vacuum during the processing was within the range of 1 to 500 Torr. Further, the wafer temperature during processing is set to 400 ° C.
When the processing pressure was set to 1 Torr and the ozone concentration was set to 150 g / m ³ , the current-voltage characteristics of the 10-minute processing under reduced pressure shown in FIG. As a result, efficient processing could be performed.

In each embodiment described above, the ultraviolet lamp 80 constituting the ultraviolet irradiation means 62 is connected to the processing vessel 4.
However, the arrangement is not limited to this, and it may be arranged inside the processing container 4. FIG. 13 shows a configuration of such a reformer, and the same components as those shown in FIG. 6 are denoted by the same reference numerals. That is, in this configuration, the ultraviolet lamps 80 constituting the ultraviolet irradiation means 62 are arranged in parallel immediately below the shower head 44 and provided in the processing container 4. Therefore, FIG.
The quartz transmission window 56 required in the configuration shown in FIG. A reflecting mirror 84 is provided on the ceiling of the container to which the shower head 44 is attached. The reflecting mirror 84 reflects ultraviolet rays directed upward from the lamp 80 downward and uses the ultraviolet rays efficiently.

The apparatus configured as described above also exhibits the same operation and effect as the apparatus shown in FIG. 6, and irradiates the processing gas such as ozone present in the processing space S with the ultraviolet light UV emitted from the ultraviolet lamp 80. As a result, active oxygen atoms 78 are generated. Then, this active oxygen atom 78 is
Acts on a metal oxide film formed on the surface of the substrate to substantially completely oxidize and modify the metal oxide film.

In this embodiment, the ultraviolet lamp 80
As a result, the lamp 80 and the wafer W can be very close to each other, and accordingly, the ultraviolet rays emitted from the lamp 80 can be effectively used. The reforming rate can be further improved. Further, as compared with the apparatus shown in FIG. 6, the light from the lamp is not absorbed by the quartz window and is not weakened. Also, because the distance between the shower head and the heating table can be increased,
Decomposition of ozone due to heat of the substrate can be suppressed. Further, in this embodiment, the reflecting mirror 84 is provided on the ceiling portion of the container, but when this is not provided, the constituent material of the shower head 44 is
Instead of quartz transparent to ultraviolet rays, ordinary stainless steel or aluminum alumite whose surface is anodized may be used. According to this, rather than using a quartz shower head that is relatively difficult to manufacture,
An increase in cost can be suppressed.

In each of the above embodiments, ozone or N ₂ O gas is irradiated with ultraviolet rays in order to generate active oxygen atoms. Instead, oxygen or N ₂ O gas is generated by plasma. Excitation may be performed to generate active oxygen atoms. FIG. 8 is a configuration diagram showing such a reformer, and the same components as those shown in FIG. 1 are denoted by the same reference numerals and description thereof is omitted. A feature of the present invention is that a plasma generating means 86 is used in place of the ultraviolet irradiation means 62 used in the previous embodiment. That is, the plasma generating means 86 has a plasma generating container 88 made of, for example, quartz or the like. The plasma generating container 88 is formed in a hollow cylindrical shape, and the lower portion is expanded in a funnel shape. ing. The plasma generating container 88 is provided at the center of the ceiling 4B of the processing container 4 so as to penetrate vertically, with its opening facing the mounting surface. 90
To provide airtightness. Therefore, the inside of the plasma generation container 88 is communicated with the inside of the processing container 4 and is configured as a part of the processing space.

On the ceiling of the plasma generating vessel 88,
A processing gas introduction nozzle 92 is provided, and a gas supply pipe 96 provided with a mass flow controller 94 on the way is connected to the nozzle 92 so that the processing gas can be introduced into the plasma generation container 88 while controlling the flow rate. It has become.
As the processing gas used here, not only ozone and N ₂ O gas used in the previous embodiment, but also oxygen gas itself can be used. Similarly, N ₂ O gas and N ₂ gas can be used. A small amount of a mixed gas of H ₂ gas may be added as an additional gas. And the upper part of the plasma generation vessel 88
Covered by a microwave receiver 98 made of a conductive material, the receiver 98 is connected via a waveguide 100 to a microwave generator 102 that generates microwaves of, for example, 2.45 GHz, and receives a processing gas. Active oxygen atoms are generated by applying microwaves directly to the surface.

In this configuration, the same operation and effect as those of the apparatus shown in FIG. 1 are produced. That is, the processing gas introduced into the plasma generation vessel 88 from the processing gas introduction gas nozzle 92, such as O ₂ gas or N ₂ O gas, is directly irradiated with the microwave of 2.45 GHz generated by the microwave generator 102. As a result, plasma is generated, and active oxygen atoms 78 are generated by the energy of the plasma. The generated active oxygen atoms 78 are supplied to a plasma generation vessel 88.
The metal oxide film formed on the wafer surface is quickly and almost completely oxidized in a short time by being poured down onto the surface of the wafer from the lower end of the container that has flowed down and expanded. It will be reformed. The pressure of the reforming process at this time is
In consideration of the plasma generation efficiency and the active oxygen atom 78 generation efficiency, the range of 0.1 to 5.0 Torr is preferable,
Further, the process temperature of the wafer is preferably in the range of 320 to 700 ° C. In particular, the effect increases as the temperature increases.

FIG. 4A is a graph showing the temperature dependence of the withstand voltage in the active oxygen treatment. The horizontal axis shows the reciprocal of the absolute temperature, and the vertical axis shows the effective electric field strength. The reforming process pressure at this time is 1.0 Torr, and the reforming time is 10 Torr.
Minutes. As is evident from this graph, the higher the process temperature during reforming, the better the withstand voltage,
In particular, the effective electric field strength of 12.5 MV / c at the lower limit of the dielectric strength voltage
It is found that the process temperature should be set to 320 ° C. or more in order to make the temperature m or more. However, since the reforming process temperature needs to be set to a temperature equal to or lower than the film forming temperature of the metal oxide film, the upper limit is 700 ° C.

FIG. 4B is a graph in which the temperature dependence of the active oxygen treatment of the insulation-resistant film is determined in more detail, and the treatment pressure is variously changed from 760 Torr of the atmospheric pressure to 0.1 Torr. According to this, as the temperature of the substrate, that is, the process pressure is increased, in the case of the atmospheric pressure, after the peak value at which the withstand voltage is most improved exists, when the process temperature exceeds 700 ° C., the characteristics are rapidly deteriorated. doing. As the processing temperature increases, the degree of vacuum at which the withstand voltage is most improved also decreases gradually. For example,
The processing temperature at which the withstand voltage is most improved is about 300 ° C. when the process pressure is 760 Torr, and 500 to 50 To.
about 400 ° C. at rr, 50 at 10 to 1 Torr
At about 0 ° C. and 0.5-0.1 Torr, the temperature is about 600 ° C. According to the graph, when the degree of vacuum is about 1 Torr or less, the processing temperature is 500 ° C. to 7 ° C.
It shows high insulation properties in the range of 00 ° C., which proves to be good properties.

FIG. 5 is a graph showing the dependence of the dielectric strength voltage on the processing time of active oxygen, comparing the case where the additive gas is added and the case where the additive gas is not added. As is clear from the graph,
It is clear that the reforming process can be performed more quickly and quickly when the additive gas is added (curve A) than when no additive gas is added (curve B). This is considered to be because the concentration of active oxygen atoms increased due to the presence of the added gas. The additive gas is here a mixed gas of N ₂ gas and H ₂ gas, one for O ₂
It is added in the amount of about%. The ratio of the N ₂ gas to the H ₂ gas is 97% to 3% and supplies 1 to 2 liters of O ₂ .

In this embodiment, since microwaves are used to generate plasma, there is no need to use ozone as compared with other embodiments. Therefore, a device such as a gas obstacle or ozone generation is not required, and the cost can be significantly reduced. Further, the microwave for generating plasma is not limited to 2.45 GHz, and a microwave of another frequency may be used. In the above embodiment, when generating plasma,
Although the microwave is used, a high frequency may be used instead. FIG. 15 shows a configuration diagram of such an apparatus, and the same components as those shown in FIG. 14 are denoted by the same reference numerals. That is, in this configuration, the high-frequency coil 104 is wound around the plasma generating vessel 88 of the plasma generating means 86 and provided to the coil 104 via the matching circuit 106, for example, at 13.5.
A 6 MHz high frequency power supply 108 is connected, and plasma is generated by applying this high frequency electric field to the processing gas.

In this embodiment, the same operation and effect as those of the embodiment shown in FIG. That is, the high-frequency power supply 108 is applied to the processing gas introduced into the plasma processing vessel 88.
By applying a high-frequency electric field of, for example, 13.56 MHz, a plasma is generated, and active oxygen atoms 78 are generated by the energy of the plasma. The active oxygen atoms 78 flow down in the plasma generating vessel 88 to quickly and almost completely reform the metal oxide film on the wafer surface in a short time. At this time, the process pressure and the wafer temperature are the same as those shown in FIG. In particular, in this embodiment, the same effect as that of a microwave can be obtained by using a high frequency for plasma generation.

In each of the embodiments described above, the case where the ultraviolet ray UV is used for performing the reforming process has been described as an example. However, if the wafer temperature is set to 400 ° C. or more, ozone can be applied to the wafer surface without using the ultraviolet ray. By virtue of the active oxygen atoms generated by thermal decomposition in the above, it is possible to efficiently improve the insulating properties of the tantalum oxide film. FIG.
6 is a block diagram showing an eighth embodiment of the apparatus of the present invention for performing such a reforming process, FIG. 17 is a bottom view showing a shower head of the apparatus shown in FIG. 16, and FIG. 6 is a graph showing the relationship of. In the illustrated example,
The same parts as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted. In this illustrated example, only the main part is described, and other parts other than the parts described here are configured in the same manner as the previous embodiment.

In this embodiment, a heating lamp 130 composed of a plurality of, for example, halogen lamps is used as a heating means, and this heating lamp 130 is placed below a quartz transmission window 56 provided at the bottom of the processing container 4. Have been placed.
Further, the mounting table 132 used here is different from the thick mounting table with a built-in resistance heating element used in the previous embodiment, and uses a very thin, for example, SiC-coated carbon mounting table. A plurality of quartz columns 13 from the bottom of the container
4 supported. Further, the shower head 44 provided in the processing container 4 includes a distribution ring tube 136 provided at a peripheral portion and a hollow disk-shaped disk head portion 140 provided at a central portion via four connection tubes 138. A large number of injection holes 46 are provided on the lower surface of the head section 140 so that a processing gas can be supplied into the processing container.

The distance L1 between the wafer W and the lower surface of the shower head 44 is made as small as possible.
It is set to about 0 mm to suppress the occurrence of gas phase reaction,
Decomposition of ozone is promoted mainly by a surface reaction. Further, a cooling jacket 72 is provided on the side wall of the processing container 4 to make it a cold wall. In the case of the above configuration, the ozone-containing processing gas introduced into the shower head 44 is supplied from the distribution ring pipe 136 to the disk head 140 via the connection pipe 138.
, And is uniformly supplied onto the wafer in the processing chamber 4 through a larger number of the injection holes 46.

On the other hand, the heat ray radiated from the heating lamp 130 passes through the transmission window 56 and strikes the back surface of the mounting table 132 to heat it, thereby indirectly heating the mounted wafer W to a predetermined temperature. become. In this case, by setting the wafer temperature within the range of 400 ° C. to 850 ° C.,
Without using ultraviolet rays, ozone can be thermally decomposed on the wafer surface to generate active oxygen atoms, and the surface of the wafer can be modified to improve the insulating properties of the tantalum oxide film. In particular, when the distance L1 between the wafer W and the shower head 44 is large, the active oxygen generated by the decomposition of the ozone released from the head 44 by the gas phase reaction on the way disappears before reaching the wafer surface. However, as in this embodiment, the surface of the wafer and the lower surface of the shower head 44 are, for example, 1
By approaching to about 0 mm, ozone is mainly decomposed on the heated wafer surface, and an extremely high concentration of active oxygen atoms can be obtained. Therefore, the generated active oxygen atoms can efficiently act on the wafer surface. As a result, the reforming process can be performed efficiently, and the characteristics of the film quality can be improved.

In this case, since the side wall of the processing vessel 4 is cooled by the cooling jacket 72 to maintain the temperature at which the ozone is thermally decomposed, for example, 300 ° C. or less, the thermal decomposition of the ozone flowing out of the surface other than the wafer surface is suppressed. Therefore, the decomposition of ozone can be promoted only on the wafer surface, and the reforming efficiency and the like can be further improved. Although ozone is contained as the processing gas, N ₂ O may be used instead. As is clear from the graph shown in FIG. 18, when a Ta ₂ O ₅ film having a thickness of 10 nm was formed, the withstand voltage of the wafer temperature peaked at 475 ° C., most preferably in the range of 450 ° C. to 500 ° C., and is preferably 400 ° C. or less. , The breakdown voltage becomes 1.
When the voltage drops below 8 volts, the characteristics deteriorate. If the temperature is 8
Up to about 00 ° C., an insulating film having good characteristics can be obtained.

When the wafer temperature was set to 400 ° C., the processing pressure was set to 1 Torr, and the processing was performed at an ozone temperature of 150 g / m ³ , the current for 10 minutes under reduced pressure shown in FIG. It took only 4 minutes or less to obtain voltage characteristics, and efficient processing could be performed. still,
In the embodiment, as the shower head structure, another structure, for example, a structure as shown in FIG. 1 may be used, or a structure with a built-in resistance heating element as shown in FIG. 1 without using a heating lamp. May be used.

In each of the above embodiments, the case of modifying tantalum oxide formed on the wafer surface as a metal oxide film to be modified has been described as an example. However, the present invention is not limited to this. For example, the present invention can be applied to the case of modifying titanium oxide, zirconium oxide, barium oxide, and strontium oxide. Further, other than the above-described metal oxide film, niobium oxide, hafnium oxide, yttrium oxide,
The present invention can also be applied when forming lead oxide or the like. In the above embodiment, a semiconductor wafer is described as an example of the object to be processed. However, the present invention is not limited to this, and may be applied to, for example, modifying a metal oxide film formed on a glass substrate or an LCD substrate. .

[0060]

As described above, according to the reforming method and apparatus of the present invention, the following excellent effects can be obtained. According to the inventions defined in claims 1 and 14, when modifying the metal oxide film formed on the object to be processed, active oxygen atoms generated by irradiating the processing gas with ultraviolet rays are converted in a vacuum atmosphere. Since it is made to act on the object to be processed, the life of active oxygen atoms can be extended to increase the density, and the metal oxide film can be quickly and quickly reformed into an insulating film having a high withstand voltage to improve the throughput. be able to. In addition, since a large amount of ultraviolet rays can be irradiated by using a mercury-filled lamp that generates ultraviolet rays by microwaves as the ultraviolet irradiation means, more active oxygen atoms are generated to perform the reforming process more quickly. Can be. Further, as an ultraviolet irradiation means,
By using an ultraviolet lamp such as a cold cathode tube, the metal oxide film can be reformed quickly and in a short time without significantly increasing the cost.

According to the invention defined in claims 4 and 15, when modifying the metal oxide film formed on the object to be processed, a microwave or a high-frequency electric field is applied to the processing gas in a vacuum atmosphere. Since plasma is generated and active oxygen atoms are generated by the energy of the plasma to act on the metal oxide film, the life of the active oxygen atoms can be extended to increase the density, and the metal oxide film can be formed quickly and in a short time. Thus, an insulating film having a high withstand voltage can be modified to improve the throughput. Further, by combining the shower head with a plurality of gas injection pipes, it is possible to prevent ultraviolet rays passing through the inside of the shower head from decreasing and absorbing the ultraviolet rays. Therefore, a large amount of ultraviolet rays can directly reach the surface of the object to be processed, and the amount of active oxygen atoms generated in the vicinity of the surface can be increased, thereby improving the reforming efficiency and improving the quality of the film. it can. In addition, by configuring the shower head as a lid that can cover the surface of the object to be processed, ozone and the like can be intensively decomposed in the lid to form high-concentration active oxygen atoms. It is possible to increase the reforming efficiency and greatly improve the properties of the film quality.

According to the eleventh aspect of the present invention, the object to be processed is heated to a temperature in the range of 400 ° C. to 850 ° C. and supplied with ozone or N ₂ O gas to use ultraviolet rays or microwaves. Thus, the reforming process can be performed efficiently, and the characteristics of the film quality can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a reformer according to the present invention.

FIG. 2 is a graph showing a relationship between irradiation time and insulation characteristics (leakage current) when ultraviolet light is irradiated in an ozone atmosphere.

FIG. 3 is a graph showing a relationship between a reforming process pressure and a withstand voltage by ultraviolet irradiation in the presence of ozone.

FIG. 4 is a graph showing the temperature dependence of the withstand voltage of the active oxygen treatment.

FIG. 5 is a graph showing the dependency of the withstand voltage on the processing time of active oxygen.

FIG. 6 is a configuration diagram showing a second embodiment of the reforming apparatus of the present invention.

FIG. 7 is a configuration diagram showing a main part of a third embodiment of the reforming apparatus of the present invention.

8 is a bottom view showing a shower head of the apparatus shown in FIG.

FIG. 9: Opening ratio of gas injection tube (100-% of projected area)
6 is a graph showing a relationship between the dielectric strength and the withstand voltage.

FIG. 10 is a configuration diagram showing a main part of a fourth embodiment of the present invention.

11 is a view showing a state where a mounting table of the apparatus shown in FIG. 10 is lowered.

FIG. 12 is a sectional view showing a shower head of the apparatus shown in FIG.

FIG. 13 is a configuration diagram showing a fifth embodiment of the reforming apparatus of the present invention.

FIG. 14 is a configuration diagram showing a sixth embodiment of the reforming apparatus of the present invention.

FIG. 15 is a configuration diagram showing a seventh embodiment of the reforming apparatus of the present invention.

FIG. 16 is a configuration diagram showing an eighth embodiment of the apparatus of the present invention that performs a reforming process.

FIG. 17 is a bottom view showing the shower head of the apparatus shown in FIG.

FIG. 18 is a graph showing the relationship between wafer temperature and dielectric strength.

[Explanation of symbols]

 2 Reforming apparatus 4 Processing vessel 12 Vacuum exhaust system 14 Mounting table 20 Resistance heating element (mounting table heating means) 47 Processing gas supply means 52 Ozone generator 56 Transmission window 62 Ultraviolet irradiation means 64 Mercury sealed lamp 66 Microwave generation means 68 Reflecting mirror 78 Active oxygen atoms 80 Ultraviolet lamp 84 Reflecting mirror 86 Plasma generating means 88 Plasma generating vessel 92 Processing gas introduction nozzle 100 Waveguide 102 Microwave generator 104 High frequency coil 108 High frequency power supply 110 Distribution ring tube 112 Gas injection tube 116 Cover Body 118 Introducing header section 122 Ejecting header section 130 Heating lamp W Semiconductor wafer (object to be processed)

Claims (19)

[Claims] In a metal oxide film reforming apparatus for reforming a metal oxide film formed on the surface of an object to be processed, a processing container which can be evacuated, and an object to be processed housed in the processing container. A mounting table on which the body is mounted, processing gas supply means for supplying a processing gas containing ozone or N ₂ O gas into the processing container, and irradiating ultraviolet rays into the atmosphere in the processing container to convert active oxygen atoms A reforming apparatus comprising: an ultraviolet irradiation means for generating; and a vacuum exhaust system for evacuating the inside of the processing container. 2. The lamp according to claim 1, wherein the ultraviolet irradiation means includes a mercury-filled lamp filled with mercury, a microwave generating means for applying a microwave to the mercury-filled lamp to generate ultraviolet rays, and The reforming apparatus according to claim 1, further comprising: a reflecting mirror that converges upward and irradiates the light uniformly. 3. The reforming apparatus according to claim 1, wherein said ultraviolet irradiation means comprises a plurality of ultraviolet lamps arranged in parallel so as to face a plane of said workpiece. 4. A reforming apparatus for reforming a metal oxide film formed on a surface of an object to be processed, wherein at least one of an O ₂ gas, an ozone gas, and an N ₂ O gas is provided. A processing gas supply means for introducing a processing gas containing any one of the processing gases into the processing container; and a microwave or a high-frequency electric field applied to a ceiling portion of the processing container to generate plasma to generate the processing gas. A reforming apparatus comprising: a plasma generating means for generating active oxygen atoms from a gas; and a vacuum exhaust system for evacuating the inside of the processing vessel. 5. The reformer according to claim 1, further comprising a mounting table heating means for heating the mounting table. 6. The processing gas supply means has a shower head disposed between the ultraviolet irradiation means and the mounting table, and the shower head is formed by combining a plurality of gas injection pipes having injection holes. The reforming apparatus according to claim 1, wherein: 7. The reformer according to claim 6, wherein the plurality of gas injection pipes are combined in a lattice shape. 8. A projection area of the plurality of gas injection tubes on the mounting table is 20% of a surface area of the object to be processed.
The reformer according to claim 6, wherein the size of the reformer is smaller than that of the reformer. 9. The processing gas supply means has a container-shaped lid having a lower end opened so as to cover an upper surface of the mounting table. An introduction header portion having an injection hole is formed, and a discharge header portion having a discharge port is formed on the other side, so as to form a gas flow flowing in the lid body in a horizontal direction. Item 6. The reformer according to any one of Items 1 to 5. 10. The reformer according to claim 9, wherein the lid and the mounting table are relatively vertically movable toward and away from each other. 11. A metal oxide film reforming apparatus for reforming a metal oxide film formed on the surface of an object to be processed, wherein the processing container is made evacuable, and the object to be processed is accommodated in the processing container. A mounting table for mounting a body, processing gas supply means for supplying a processing gas containing ozone or N ₂ O gas into the processing container, heating means for heating the object to be processed, A vacuum evacuation system for evacuating the object;
A reforming apparatus characterized in that it is heated within the range of ° C. 12. The reformer according to claim 11, wherein said heating means comprises a plurality of heating lamps provided below said mounting table. 13. A cooling jacket for cooling the side wall of the processing container to a temperature lower than the thermal decomposition temperature of ozone on the side wall of the processing container.
13. The reformer according to 1 or 12. 14. A method for modifying a metal oxide film formed on a surface of an object to be processed, wherein ultraviolet rays are irradiated into a vacuum atmosphere of a processing gas containing ozone or N ₂ O gas to generate active oxygen atoms, A reforming method characterized in that the metal oxide film on the surface of the object is modified by the active oxygen atoms. 15. A method for modifying a metal oxide film formed on a surface of an object to be processed, wherein the method comprises the steps of: placing a processing gas containing at least one of O ₂ gas, ozone and N ₂ O gas in a vacuum atmosphere; A reforming method characterized in that active oxygen atoms are generated by applying a microwave or a high-frequency electric field, and the metal oxide film on the surface of the object to be processed is modified by the active oxygen atoms. 16. The reforming method according to claim 14, wherein an additional gas containing at least a trace amount of N ₂ gas is mixed in the processing gas. 17. The pressure of the vacuum atmosphere is 1 to 600.
17. The reforming method according to claim 14, which is set within a range of Torr. 18. The temperature of the object to be processed during the reforming is 32
18. The reforming method according to claim 14, wherein the temperature is set within a range of 0 to 700C. 19. The reforming method according to claim 14, wherein the metal oxide film contains any one of tantalum oxide, titanium oxide, zirconium oxide, barium oxide, and strontium oxide.