JPH0713949B2 - Photoreaction method and device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a photoreaction device used for various reactions in a device manufacturing process such as thin film formation and etching.

[Prior Art] With the high integration and high performance of integrated circuits, thin film formation,
In various LSI manufacturing processes such as etching and oxidation, optical processes have been studied in which the above-mentioned various processes are performed by activating the reaction gas, the substrate surface, etc. with light in order to lower the process temperature and prevent damage. There is.

FIG. 11 shows the structure of a photoreaction device used in a conventional optical process. Reference numeral 1 denotes a light source, for example, a mercury lamp, a rare gas lamp, or various laser light sources such as an excimer laser and a carbon dioxide gas laser. 3 is the light emitted from the light source 1,
The substrate 13 on the substrate holder 11 having the heater 11A is irradiated with the photoreaction gas 9 through the light introduction window 7 of the reaction container 5.
A thin film is formed on the surface layer of, and processing such as etching is performed. 15
Is an inlet valve for the reaction gas 9, and 17 is an exhaust device. For the photoreaction, the inside of the container 5 is usually evacuated by the exhaust device 17,
At 15 the reaction gas 9 is introduced, the container 5 is filled with the reaction gas 9 at a pressure of several Torr to several hundred Torr, and then the light source 1 is turned on.
By irradiating the surface of the gas 9 or the substrate 13 with the light 3, the reaction such as the gas activated by the light or the reaction between the gas and the substrate is used to perform processing such as thin film formation or etching. With such a structure, the wavelength of the light 3 with which the reaction gas 9 is irradiated is limited. That is, when the light source 1 is a mercury lamp or a laser, it has a structure in which mercury vapor is enclosed in a mercury lamp and gases such as Ar and F are enclosed in an ArF excimer laser. The shortest wavelength of the generated light is limited.
For example, if the sealed tube is quartz, 2000Å, if LiF, 1060
It is impossible to obtain Å with a wavelength less than Å. Further, the light introduction window 7 for introducing light into the reaction container 5 may also absorb the short wavelength light and may not irradiate the reaction gas 9. On the other hand, in general, the wavelength of light that is strongly absorbed by the reaction gas and activated by exciting, decomposing, or ionizing the reaction gas is 1500 Å or less. In particular, light of 1000Å or less is strongly absorbed. For example, Figure 12 shows the absorption characteristics of silane (SiH ₄ ) gas frequently used in integrated circuit manufacturing (Y. Haradaet
al.Chem.phys.lett.1, p.595-596 (1968)).

Absorption increases sharply at wavelengths below 1300Å, and wavelengths in this region are considered suitable for activating SiH ₄ . However, as described above, in the conventional method, since the light having a short wavelength is absorbed by the enclosing tube of the light source or the light introduction window, 1100
It was impossible to irradiate light with a wavelength below Å. Therefore, conventionally, when a silicon (Si) thin film is formed of silane (SiH ₄ ), a gas that absorbs the wavelength of the light source well, for example, when using a mercury lamp, the silane gas is mixed with mercury vapor, and the mercury of the lamp is mixed. The light generated from the atoms excites the mercury atoms, and the collisions between the excited mercury atoms and SiH ₄ excite the SiH ₄ molecules to increase the activation degree and the film formation rate. However, with this method, a good quality film could not be formed, for example, mercury was included in the manufactured film. In addition, as shown in Fig. 11, the number To
When a reactive gas of rr to several hundred Torr is filled and reacted by irradiating light, a reaction product adheres to the light introduction window 7. For example, when forming a thin film, the adherence of the window reduces the light transmittance and stabilizes. Therefore, it was impossible to form a film for a long time.

Furthermore, the reaction gas molecules excited by light have an average free path of 0.1 mm or less at a gas pressure of several Torr or more, so the gas molecules excited before reaching the substrate are other gas molecules. Since the excited state cannot be sustained and only a small proportion of the reaction gas molecules excited by light reach the surface of the substrate, the reaction on the surface of the substrate is less likely to occur, and adhesion by photoreaction is conventionally required. The reaction rate of etching, etching, etc. was much lower than that of other processes such as plasma process.

Further, as described above, since the wavelength of the light generated from the light source is long, the reaction gas is less likely to be ionized by photoionization, and the photoionized gas molecules are neutralized by collision with other gas molecules. It did not reach the substrate and it was impossible to use photoionized ions. Therefore, the reaction cannot be controlled by an electric field or a magnetic field, and the controllability of the reaction was low.

On the other hand, there is a synchrotron radiation light source as a light source capable of generating light having a wavelength of 1000 Å or less and causing the above-mentioned photoreaction.
However, since the synchrotron radiation source requires a high vacuum of about 10 ^-9 Torr and is a large device, a large capacity differential exhaust system is required to directly irradiate the reactive gas with the synchrotron radiation. However, it is difficult to make a simple photoreaction device. In addition, conventional vacuum ultraviolet light sources such as capillary discharge tubes cannot be used in high vacuum because they constantly flow gas, and the light intensity is extremely weak. Is impossible to use.

[Problems to be Solved by the Invention] The present invention has the above-mentioned drawbacks of the related art, that is, it is difficult to obtain light having a wavelength most suitable for photoreaction, light is attenuated before irradiation of a reaction substance, and an apparatus is used. We solved the problem of being large-scale, and activated the reaction gas with light from a light source that generates light of a wavelength suitable for photoreaction, and activated it with high efficiency by ionization, and the activated reaction gas It is an object of the present invention to provide a photoreaction method and device that reach a substrate without disappearing.

[Purpose for Solving Problems] In order to achieve such an object, in the photoreaction method of the present invention, the first gas is injected into the plasma forming chamber and the plasma forming chamber is provided with the first gas. A pulsed voltage is applied between the electrodes to form a pulsed plasma, the pulsed electromagnetic radiation generated from the plasma is guided to the photoreaction chamber, and the electromagnetic radiation is injected into the photoreaction chamber in a pulsed manner. It is characterized in that the irradiated second gas is irradiated to activate the second gas to cause a reaction on a substrate arranged in the photoreaction chamber.

Further, in the photoreaction device of the present invention, a plasma forming chamber provided with a counter electrode for forming plasma, means for applying a voltage in a pulsed manner between the electrodes to generate a plasma in a pulsed manner, Means for injecting a first gas, a photoreaction chamber having a second gas inlet for causing a photoreaction and housing a substrate, and injecting the second gas in a pulsed manner into the photoreaction chamber And a light introducing tube that directly connects the plasma forming chamber and the photoreaction chamber so as to directly irradiate the second gas with pulsed electromagnetic radiation generated from the plasma.

[Operation] FIG. 1 shows the basic configuration of the device of the present invention. The operation of the present invention will be described with reference to the drawings. 21 is the plasma that becomes the light source,
It is formed by the discharge electrodes 23, 25. The light 27 generated from the plasma is applied to the gas mass 29. Molecules forming the gas mass 29 reach the substrate 31 in the form of a molecular flow having the same direction and velocity, as indicated by the arrow indicating the molecular motion. The plasma forming container 33 and the reaction container 35 are connected by a light introducing tube 37.

In the present invention, the light 27 generated from the plasma 21 which is formed in a pulsed manner by the discharge is used to generate a molecular flow-like gas mass 29 with a uniform direction.
The molecules or ions that are irradiated with the light and activated by the light reach the substrate 31 as they are without collision on the way and cause a reaction on the surface of the substrate. Therefore, it is possible to irradiate the reaction gas with light in the entire wavelength region generated from the light source, and in particular, the reaction gas can also be irradiated with extreme ultraviolet light having a wavelength of 1000 Å or less, which is most suitable for gas excitation and solid surface activation. For this reason, the degree of activation of the reaction gas is increased, and there is an advantage that the reaction gas can be ionized, which was impossible in the conventional photoreaction. Further, since the gas of the light source can be freely selected, it is possible to resonantly excite the reaction gas by using a gas that emits light having a wavelength suitable for excitation of the reaction gas as the light source. Furthermore, the gas molecule flow whose directions are aligned in a vacuum can be excited and activated by light to reach the substrate surface without losing the activated state, so that the reaction can be efficiently generated on the substrate surface. Furthermore, since ions having extremely small energy dispersion generated by photoionization can be irradiated onto the substrate, the reaction on the substrate surface can be controlled with high accuracy.

[Embodiment] FIG. 2 is a diagram for explaining the first embodiment of the present invention.
41 is a photoreaction container, 43 is a reaction container exhaust device, 45 is a light source discharge container, and 47 is a light source exhaust device. 49 is a high-speed opening / closing gas valve for injecting a reaction gas into the light reaction container 41, 51 is a power supply for driving the high-speed opening / closing gas valve 49,
53 is a pulse generator for issuing a drive command to the power supply 1, 55 is a container of reaction gas injected into the photoreaction container 41 by the high speed opening / closing gas valve 49, and 57 is reaction gas 58 ejected from the high speed opening / closing gas valve 49. The skew 59 for adjusting the shape of the gas mass to be formed is a reaction gas mass formed by being injected into the vacuum by the high-speed opening / closing gas valve. Reference numeral 61 is a high-speed opening / closing gas valve for injecting a light source gas, 63 is a drive power source for the light source gas high-speed opening / closing gas valve, and the high-speed opening / closing gas valve 61 is driven by a trigger pulse of a pulse generator 53. Reference numeral 65 is a container for the light source gas 66. 67 is a discharge electrode for injecting a gas for a light source, which has a gas injection hole at the center. 67A is a high voltage introducing flange for guiding high voltage to the electrode 67, and 69 is a gas injection electrode
The return electrode facing 67 is hollow. 69A is a gas vent hole of the discharge electrode 69, 69B is a light extraction hole of the return electrode 69, 69C is a return current flange for guiding the current from the return electrode 69 to the power supply, and 69D is a high voltage introduction flange 67A and a return current. An insulator 71 for insulating the flange 69C is a discharge power source, and is electrically connected to the high voltage introducing flange 67A and the return current flange 69C. 7
Reference numeral 3 is a high-temperature, high-density plasma formed by the light source gas 66 from the gas container 65 being discharged between the electrodes 67 and 69 into plasma, self-focusing by the current from the power source 71, and ultraviolet and visible light from this plasma. Electromagnetic radiation such as ultraviolet rays, vacuum ultraviolet rays, and X-rays is generated. Hereinafter, these electromagnetic radiations are collectively referred to as light. 75 is the light emitted from the plasma 73, 77 is the light 75
A light introducing tube for guiding the light from the discharge vessel 45 to the photoreaction vessel 41, 79 is a magnet such as a permanent magnet or an electromagnet, and plasma
This is to remove the electrons generated when 73 collapses by deflecting them with a magnetic field.

81 is a metal mesh for removing ions from the plasma 73. Reference numeral 83 is a power source for applying a potential to the mesh 81. 85 is a substrate holder, a heater for heating the substrate
Has 85A. 87 applies a potential to the substrate 89, and the substrate 8
A power supply to control the incident energy of the ions to 9,
It is provided as needed. For example, by providing a metal mesh to which an electric potential is applied at an appropriate position in the reaction container 41,
An electric field can be applied to the gas mass to control the energy incident on the substrate.

The substrate 89 is installed at a position facing the skew 57 from which the reaction gas 58 is discharged. In this embodiment, since the photoreaction container and the discharge container are provided with exhaust devices independently of each other,
Both containers can be efficiently evacuated to a vacuum degree suitable for photoreaction and plasma formation. Further, for example, a gate valve may be provided in the light introducing tube 77 so that the inside of the light reaction container 41 and the inside of the discharge container 45 can be independently evacuated.

To operate this, the inside of the light reaction container 41 is exhausted by an exhaust device 43,
The inside of the discharge container 45 is evacuated by the exhaust device 47 and maintained at a predetermined vacuum, for example, about 10 ⁻⁶ Torr. Next, in order to drive the high-speed opening / closing gas valve 49 for reaction gas, a pulse generator 53 sends a power source drive command trigger to the high-speed opening / closing gas valve driving power source 51, and the power source 51 is operated to drive the valve 49 to drive the inside of the gas container 55. The reaction gas 58 is injected into the light reaction container 41 through the skew 57 to form a reaction gas mass 59. To generate light, the pulse generator 53 generates a high-speed gas valve drive command trigger for the reaction gas, and then a drive command trigger to the power supply 61 for driving the light source gas valve 61 from the pulse generator 53 at an appropriate time interval. Then, the valve 61 is operated to emit the light source gas 66 between the electrodes 67 and 69. The pulse generator 53 sends a drive command trigger to the discharge high-voltage power supply 71 to operate the power supply 71 within a time period during which the light source gas 66 does not diffuse between the electrodes, and a high voltage is applied to the electrode 67 to discharge the plasma. To form. A current is made to flow from the power source 71 between the electrodes 67 and 69, and the plasma formed by the discharge is self-focused by the interaction with the magnetic field created by the current. High-temperature, high-density plasma 73 is formed on the central axes of the electrodes 67 and 69 by the self-focusing of plasma, and light is generated.

The light 75 generated from the plasma is introduced into the light reaction container 41 through the light introduction tube 77. The light introduction tube 77 is provided with a magnet 79 and a mesh 81 that create a magnetic field perpendicular to the traveling direction of light, and the light 75 is irradiated to the reaction gas mass 59 through the magnetic field of the magnet and the mesh. The gas lump 59 reaches the surface of the substrate 89 facing the skew 57 and reacts after being activated by being excited and ionized by the infrared light of the light 75, visible light, ultraviolet light, vacuum ultraviolet light, X-ray, and the like. Occurs.

Since this embodiment has such a structure, both the reaction gas and the light source gas are supplied in a pulsed manner, no partition wall or window is required between the light source and the reaction vessel, and the reaction gas mass is not required.
When 59 is illuminated, the path of light from the light-producing plasma 73 is maintained in a vacuum. Therefore, it is possible to irradiate the reaction gas mass with light of any wavelength generated from plasma. Most of the electrons and ions generated when the high-temperature / high-density plasma generates light and then collapses is radiated in the axial direction of the plasma, but part of it is also radiated in the radial direction of the reaction vessel 41. However, in this embodiment, the electrons are bent by the magnetic field of the magnet 79, the ions are absorbed by the mesh 81, and the ions are absorbed by the reaction vessel.
I can't enter 41. In addition, before and after plasma formation
The light source gas 66 ejected from 61 is an electrode 67 ejecting the gas.
Since the gas is ejected toward the exhaust device 47 arranged so as to face, the gas is efficiently exhausted, and the light source gas flowing into the reaction container 41 is small. Therefore, the reaction gas mass 59 is irradiated with light without charged particles, gas, etc. flowing into the reaction container from the light source. In order to use electrons or ions generated from plasma with light, the magnet 79 may be removed and the potential applied to the mesh 81 may be changed.

FIG. 3 shows an embodiment of the skew 57 and the gas outlet of the high speed opening / closing gas valve 49 for injecting the reaction gas 58 into the reaction container 41. 49A is the piston of high-speed switching gas valve 49, Ti, Al, Fe
It is made of metal such as. This is driven by the electromagnetic force generated in the coil 49B. 49C is a gas outlet.

49D is a gas reservoir for the reaction gas 58 ejected by the high-speed opening / closing gas valve. The pressure of the gas stopper 49D is sufficiently higher than the pressure of the reaction vessel 41, and the mean free path of the gas is the gas ejection port.
When the diameter is sufficiently smaller than the diameter of 49C, the gas ejected from the gas ejection port 49C becomes a supersonic flow and becomes a molecular mass with uniform velocity and direction of motion. The shape of the molecular mass can be changed by the shape of the skew 57, which has a tapered and divergent structure (B. Bederson and WLFite edit. “Atomic and
Election Physics Atomic Interactionpart A. "in seri
es “Methods of Experimental physics vol.7 (Academi
c Press NY, 1968). Using the high-speed on-off gas valve and skew of such a structure, the reaction gas mass 58
Is a gas molecule stream in which the moving directions of the reaction gas molecules are uniformly aligned in the direction perpendicular to the substrate surface, so active molecules and ions that are excited or photoionized by light irradiation are other molecules. It will be transported to the substrate without colliding with ions. Since the molecules and ions activated by light reach the substrate without losing their activity, the reaction rate on the surface of the substrate is higher than that of a conventional photoreactor under a constant gas pressure.

FIG. 4 shows the light (current) from the plasma when argon is used as the light source gas 66 and nitrogen is used as the reaction gas 58 in the apparatus shown in FIG.
40 KA discharge), and the charged particles generated at that time are measured at the position of the substrate 89, that is, a Faraday cup is installed in the gas flow direction and the time change of the charged particle flow is measured. FIG. 5 shows the results of measurement with a Faraday cup installed at a position perpendicular to the gas flow direction. Ion flow is detected in the gas flow direction as shown in FIG. 4, but is hardly detected in the direction perpendicular to the gas flow as shown in FIG. This result shows that the nitrogen gas is ionized by the light from the plasma. This is because in the configuration of the embodiment shown in FIG. 2, the space between the light source and the reaction gas is vacuum and there is no quartz window, so that the reaction gas can be irradiated with light having a wavelength of 1000 Å or less generated from the plasma 73. This is because the gas is photoionized. This result is very different from that which was not ionized by light in the conventional photoreactor. Further, since ions are not detected in the direction perpendicular to the gas flow, it can be seen that the ions generated by photoionization do not change their direction during ionization and move in the same direction as the gas molecule flow. That is, most of the gas molecules ionized by light reach the substrate surface. Therefore, the reaction rate can be significantly improved as compared with the conventional photoreaction device.

FIG. 6 shows the result of measurement with the time axis of FIG. 4 magnified 10 times. In Fig. 6, the shortest distance from the ion generation position to the detector (distance from the lowest position of the gas mass irradiated by light to the detector) is about 10 cm, and the time required for the ions to reach the detector is about 10 cm. The ion velocity is 700 because it is 130 μs.
It becomes ~ 800 m / s, and the kinetic energy of ions is about 50 meV. From this, in the configuration of the embodiment shown in FIG.
The energy of the ions generated by photoionization is about thermal energy, and if a voltage is applied to the substrate, as shown in Fig. 2, an ion stream with a very uniform energy distribution of about 50 meV is applied to the substrate surface. I understand that This is different from the conventional ion flow obtained by extracting the ions in the plasma, which has an energy dispersion of several tens of eV, which is equivalent to the ion temperature of the plasma.
It shows that an ion flow as small as 1/1000 can be obtained.
Since the incident energy to the substrate can be controlled by meV, the reaction on the substrate surface can be controlled with extremely high accuracy.

FIG. 7 shows the results of measuring the ion species of the ion flow shown in FIG. 4 with a quadrupole analyzer. Since the nitrogen molecule N ₂ is decomposed and ionized into the monatomic ion N ⁺ , the plasma 73
It can be seen that the light generated from the light efficiently decomposes.

For example, to etch a Si substrate, SF ₆ or CF ₄ is used as an etching gas. After the substrate is installed and heated by a heater to a predetermined temperature, for example, about 100 ° C., SF ₆ is irradiated from the high-speed open / close gas valve 49, decomposed and ionized by light and irradiated on the substrate. At this time, Kr or Ar is used as the light source gas.
The same SF ₆ as the rare gas or the etching gas is used. Since the ions and excited molecules in the same direction collide with the substrate, it is possible to perform etching with a pattern having a high aspect ratio. Further, since the ion energy is extremely small, damage due to etching is extremely small.

In order to form a Si film, SiH ₄ or Si ₂ H ₆ is used and jetted from the gas valve 49. After heating the substrate such as Si to 200 to 300 ° C., for example, Si ₂ H ₆ is injected by the gas valve 49 and decomposed and ionized by light. At this time, the light source gas may be a rare gas such as Kr or Ar, or the same gas as the film forming gas. By changing the light source gas and the substrate temperature, it becomes possible to form an amorphous / polycrystalline or epitaxial film.

FIG. 8 shows an embodiment of a photoreaction device in which light irradiates a substrate with a reaction gas. In the figure, the same parts as those of the embodiment of FIG. The characteristic of this embodiment is the substrate
89 is placed in the irradiation area of the light 75. Needless to say, the position of the substrate 89 is not limited to the illustrated position. Fast open / close gas valve 49 and skew 57 are substrate 89
It is provided so as to face the position corresponding to.
Reference numeral 78 denotes a gate valve provided in the light introducing tube, which is provided for independently evacuating the reaction vessel 41 and the discharge vessel 45. Similar to the embodiment shown in FIG. 2, a magnet and a metal mesh may be provided.

In order to operate this, the inside of the reaction vessel 41 and the discharge vessel 45 is evacuated to reach a predetermined degree of vacuum, for example, 1 × 10 ⁻⁶ Torr, and then the gate valve 87A is opened.
The procedure is similar to that of the illustrated embodiment.

Due to this structure, the high-speed opening / closing gas valve 49
When the reaction gas 58 injected into the reaction container 41 reaches the substrate 89 by operating the discharge power source 71 to generate plasma and irradiate light, the reaction gas is activated by the light and the substrate The surface layer of 89 is also heated and activated by light, which has the effect of accelerating the reaction on the surface.

As described above, in the embodiment shown in FIGS. 2 and 8, the gas for the light source can be freely selected from gases that generate light having a wavelength suitable for exciting the reaction gas. In the conventional photoreaction process, the gas species of the light source was limited to some gases such as mercury and rare gas, so it did not match the light absorption characteristics of the reaction gas, and the light absorption by the reaction gas was low, Part of the light was transmitted, and as a result, the light excitation efficiency was low. On the other hand, in the present invention, since the light source gas can be freely selected, for example, the same gas as the reaction gas can be used to cause the reaction gas to be resonantly absorbed. As a result, the reaction gas can be strongly activated even with weak light.

By utilizing the characteristics of the present invention as described above, it is possible to alternately excite a plurality of reactive gas species to reach the substrate surface alternately.

FIG. 9 shows an embodiment of a photoreactor using a plurality of reaction gases. In the figure, the same parts as those of the embodiment of FIG. 55A, 55B, 55C are containers for the reaction gases 58A, 58B, 58C, 49A, 49B, 49C are high-speed open / close gas valves for injecting the reaction gases 58A, 58B, 58C into the reaction container 41, 51A, 51B, 51C are Each is a power source for a high-speed on-off gas valve. 65A and 65B are gas for light source
66A and 66B containers, 61A and 61B are high-speed open / close gas valves for injecting light source gas 66A, 66B between electrodes 67, 69, and 63A and 63B are gas valves 61A and 61B, respectively.
B power source. Reference numeral 53 is a pulse generator for controlling each high-speed gas valve and the discharge power source 71. The light introducing tube 77 is provided with an eighth structure so that the reaction container 41 and the discharge container 41 can be independently evacuated.
A gart valve similar to that shown may be provided. If necessary, a magnet or a metal mesh may be provided as shown in FIG.

To operate this, as an example, the reaction gas 58A from the reaction gas container 55A is supplied with the light source gas 66A from the light source gas container 75A.
Then, the reaction gases 58B and 58C are simultaneously injected to be excited by the light source gas 66B. As a result, the reaction gas 5
Excited molecules of 8A, 58B, and 58C are alternately irradiated, and, for example, an extremely thin multilayer film is attached to the substrate. Here, when the reactive gases 58B and 58C are irradiated at the same time, the speed of the gas depends on the gas molecular mass.
And the opening and closing time of 49B is adjusted by the trigger pulse generator 53,
It is sufficient to reach the light irradiation area at the same time.

For example, to form AlGaAs / GaAs, Al (C
The ₂ H _{5) 3,} the Ga (CH _{3) 3} to 58B, may be used an organometallic gas such as AsH ₃ to 58C. In addition, CH ₄ or C ₂ H ₆ is used as gas 58A, and WF ₆ is used as gas 58B and 58C to form a W / C multilayer film for an X-ray mirror.
And the like H _2, injecting alternating gas 58A and 58B and 58C, it may be formed by light irradiation. Ar or Kr for the light source gas
Etc. can be used.

In the above examples, a method of irradiating light by forming a gas lump in a vacuum by using a high-speed open / close gas valve for supplying the reaction gas. On the other hand, it is also possible to steadily flow the gas for light irradiation without using the high-speed opening / closing gas valve. FIG. 10 shows an embodiment of an apparatus which does not use a high speed opening / closing gas valve. 91 is a nozzle for ejecting the reaction gas 58 to the reaction vessel 41, 93
Is a flow rate adjusting valve for adjusting the flow rate of the reaction gas 58, and 95 is a molecular flow of the reaction gas and is exhausted by the exhaust device 43. Reference numeral 97 is an exhaust device provided in the light introducing tube 77 to exhaust the gas flowing from the reaction container 41 into the light source container to maintain the discharge container 45 at a predetermined pressure.

To operate this, the reaction gas 58 is made to flow from the nozzle 91 into the vacuum while adjusting the flow rate adjusting valve 93, and the gas molecule flow 95
To form. Plasma 73 is formed by discharge, light is irradiated to the gas molecule flow 95 to activate the gas, and the activated reaction gas collides with the substrate 89 provided in the middle of the gas flow, forming a film on the substrate surface, etching. And the like.

In this embodiment, the pressure inside the discharge vessel 45 can be discharged to 10 ⁻⁴ Torr.
Since it is necessary to keep it at or below it, the exhaust device 97 is necessary to reduce the gas flowing from the reaction vessel 41. The amount of gas that can be flown can be increased according to the capacity of the exhaust device 97.

It is also possible to use a metal vapor source by providing a metal vapor source (for example, a metal heated by a filament or an electron beam) used for vacuum deposition at a position corresponding to the nozzle 91 of the embodiment shown in FIG.

[Effects of the Invention] As described above, according to the present invention, it is possible to irradiate a reaction gas with light in all wavelength regions generated from a light source,
The most suitable wavelength for excitation of gas and activation of solid surface 10
It is possible to irradiate the reaction gas with extreme ultraviolet light below 00Å. Therefore, the degree of activation of the reaction gas is increased, and there is an advantage that the reaction gas can be ionized, which was impossible in the conventional photoreaction.
Further, since the gas of the light source can be freely selected, it is possible to resonantly excite the reaction gas by using a gas that emits light having a wavelength suitable for excitation of the reaction gas as the light source. Furthermore, the gas molecule flow whose directions are aligned in a vacuum can be excited and activated by light to reach the substrate surface without losing the activated state, so that the reaction can be efficiently generated on the substrate surface. Further, since ions having extremely small energy dispersion generated by photoionization can be irradiated onto the substrate, there is an advantage that the reaction on the substrate surface can be controlled with high accuracy.

As described above, according to the present invention, the reaction on the substrate surface can be accurately controlled by the highly active reaction gas, so that a thin film can be formed or processed on the substrate surface in the atomic layer order.

INDUSTRIAL APPLICABILITY Since the present invention has a high excitation efficiency of the reaction gas, it can be used for various optical processes such as photo-CVD, photo-etching and photo-oxidation. Further, when the surface of the substrate is irradiated with light, the surface of the substrate is activated, so that it can be used for crystal film growth, photodoping and the like.

Since the reaction on the substrate surface can be controlled with high accuracy, it can be applied to the formation of a lattice film. Further, it can be applied to analysis of gas components, analysis of solid surface, and the like.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram for explaining the operation of the present invention, FIG. 2 is a configuration diagram of an embodiment of the photoreaction device of the present invention, and FIG. 3 is a sectional view of a gas outlet and a skew of a high-speed opening / closing gas valve, FIG. 4 is a diagram showing the time change of the ion flow detected in the gas molecule flow direction when light is irradiated to the gas molecule flow mass formed by the high-speed opening / closing gas valve, and FIG. 5 is a direction perpendicular to the gas molecule flow direction. Fig. 6 is a diagram showing the time variation of the ion current detected by Fig. 6, Fig. 6 is a diagram showing the time variation of the ion current when the time axis of Fig. 4 is expanded by 10 times, and Fig. 7 uses N ₂ as the reaction gas. Fig. 8 shows the measurement results of the ion species photolyzed by photolysis, Fig. 8, Fig. 9 and Fig. 10 are schematic diagrams of the embodiment of the photoreaction device of the present invention, respectively. partial cross-sectional view of a conventional optical reactor causing photoreaction in the gas, FIG. 12 silane (SiH ₄₎ It is a characteristic diagram showing the light absorption properties. 1 ... Light source, 3 ... Light, 5 ... Reaction container, 7 ... Light introduction window, 9 ...
Photoreactive gas, 11 ... Substrate holder, 13 ... Substrate, 15 ... Reactive gas introduction valve, 17 ... Exhaust device, 21 ... Plasma, 23, 25 ...
Discharge electrodes, 27 ... Light, 29 ... Gas mass, 31 ... Substrate, 33 ... Plasma forming vessel, 35 ... Reaction vessel, 37 ... Light introducing tube, 41 ... Photoreaction vessel, 43, 47 ... Exhaust device, 45 ... Discharge Container, 49,61 ... High-speed open / close gas valve, 51,63 ... High-speed open / close gas valve power supply, 5
3 ... Pulse generator, 55 ... Reaction gas container, 57 ... Skew, 5
8 ... Reactive gas, 59 ... Gas mass, 65 ... Gas container for light source, 66 ...
Light source gas, 67,69 ... Discharge electrode, 69B ... Light extraction hole,
71 ... Discharge power supply, 73 ... Plasma, 75 ... Light, 77 ... Light introducing tube, 79 ... Magnet, 81 ... Metal mesh, 83 ... Mesh power supply, 85 ... Substrate holder, 87 ... Substrate power supply, 89 ... Substrate, 91 ...
Nozzle, 93 ... Flow control valve, 95 ... Reactive gas molecular flow, 97
… Exhaust system.

Claims (8)

[Claims] 1. A first gas is injected into a plasma forming chamber, and a voltage is applied in a pulsed manner between electrodes provided in the plasma forming chamber to form a pulsed plasma, which is generated from the plasma. Pulsed electromagnetic radiation to the photoreaction chamber, and irradiating the electromagnetic gas to the second gas pulse-injected into the photoreaction chamber to activate the second gas, A photoreaction method, which comprises causing a reaction on a placed substrate. 2. The pulsed formation of the plasma and the second
2. The photoreaction method according to claim 1, wherein the pulsed injection of the gas is generated by a single trigger. 3. A plasma forming chamber provided with a counter electrode for forming plasma, means for applying a voltage in a pulsed manner between the electrodes to generate a plasma in a pulsed manner, and a first gas between the electrodes. Means for injecting, a photoreaction chamber having a second gas introduction port for causing a photoreaction and housing a substrate, means for injecting the second gas in a pulsed manner into the photoreaction chamber, and from the plasma A photoreaction device comprising: a light introducing tube that directly connects the plasma forming chamber and the photoreaction chamber so that the generated pulsed electromagnetic radiation is directly irradiated to the second gas. 4. The photoreactor according to claim 3, wherein the means for injecting the second gas is a high-speed on-off valve. 5. The photoreaction device according to claim 3, wherein the plasma formation chamber and the photoreaction chamber are connected to independent exhaust devices. 6. The light according to claim 3, further comprising means for applying a magnetic field that is not parallel to the traveling method of the electromagnetic radiation into the light introducing tube. Reactor. 7. The light reaction device according to claim 3, wherein a metal mesh is provided inside the light introducing tube. 8. The photoreaction device according to claim 3, further comprising means for applying a voltage to the substrate.