JP4195525B2 - Surface treatment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to provision of a surface treatment method using plasma that generates hydrogen atoms. In particular, while taking advantage of the characteristics of the downstream processing method that does not cause physical damage to the surface of the work piece and that generates less active particles that cause inconvenient phenomena to achieve the target surface treatment, Surface treatment of a workpiece in which hydrogen atoms are involved by mixing a gas containing at least a molecule containing halogen as a constituent element with a gas containing molecules as an atomic constituent element to generate a hydrogen atom by converting the mixed gas into plasma. The present invention relates to a surface treatment method and an apparatus for realizing the surface treatment method.
[0002]
In particular, among the above-described molecules containing halogen as a constituent element, by using a molecule in which the halogen is at least one of chlorine, bromine, and iodine and does not contain an oxygen atom as a constituent element, the oxygen atom can be processed. The present invention relates to a surface treatment method and a device for realizing the surface treatment method, characterized in that surface treatment of a workpiece involving hydrogen atoms can be performed while eliminating the influence of the above.
[0003]
[Prior art]
In recent years, several methods have been reported in which a gas containing hydrogen as a constituent element is turned into plasma and the surface of various substances is treated using the action of hydrogen atoms. First, Japanese Patent Publication No. 7-75229 and U.S. Pat. S. P. As a specific example, US Pat. No. 5,403,436 shows a method of removing hydrogenated organic polymer film by ion implantation by increasing the concentration of hydrogen atoms in the plasma by processing in plasma in which water vapor is added to hydrogen molecules. U. S. P. 5089441 to hydrogen molecules and germane (GeH ₄ ) Or a gas mixed with hydrogen chloride, hydrogen bromide, and hydrogen fluoride is converted into plasma, and a semiconductor substrate is placed downstream thereof to dry clean the surface of the semiconductor substrate. By using a gas in which water vapor is mixed with hydrogen, a large amount of hydrogen atom concentration can be secured even downstream of the plasma (J. Kikuchi, S. Fujimura, M. Suzuki, and H. Yano, “Effect of H”). ₂ O on atomichigen generation in hydrogen plasma ", Jpn. J. Appl. Phys., 32, 3120-3124 (1993).) This method produces a large amount of hydrogen atoms in the plasma, It is significant in that a reducing atmosphere is provided by transporting to a downstream region where the influence of high-energy particles such as ions and photons can be substantially ignored.
[0004]
Further, nitrogen trifluoride (NF) is placed downstream of the steam-added hydrogen plasma. ₃ It was discovered that the natural oxide film on the silicon surface placed further downstream can be removed at a low temperature by adding (J. Kikuchi, M. Iga, H. Ogawa, S. Fujimura, and H. Yano, " Native oxide removal on Si surfaces by NF ₃ -Added hydrogen and water vapor plasma downstream treatment ", Jpn. J. Appl. Phys., 33, 2207-2211 (1994)). ₃ Additive H ₂ + H ₂ The natural oxide film removal method by O-plasma downstream processing is performed in a conventional high-temperature hydrogen gas atmosphere by removing the natural oxide film on the silicon surface in a vacuum at a low temperature near room temperature and realizing a hydrogen-terminated surface. The pre-treatment for the epitaxial growth of silicon that has been performed can be greatly reduced in temperature (J. Kikuchi, M. Nagasaka, S. Fujimura, H. Yano, and Y. Horike, “Cleaning of silicon surface by NF ₃ -Added hydrogen and water-vapor plasma down-stream treatment ", Jpn. J. Appl. Phys., 35, 1022-1026 (1996)), and the possibility of cleaning highly integrated semiconductor devices in electrode windows is shown. (Jun Kikuchi, Miki Suzuki, Mitsuaki Nagasaka, Shuzo Fujimura “NF to Hydrogen + Water Vapor Plasma Downflow” ₃ Removal of native oxide film on Si surface by addition (Part 4) "44th Annual Meeting of the Japan Society of Applied Physics (29p-W6)), a technology expected to have many applications in silicon semiconductor manufacturing processes It is. In addition, the downstream shown in the cited document and the downstream shown in this specification are synonymous. It should be noted that Japanese Patent Application Laid-Open No. 6-338478, which is considered to have patented this technology, describes NF in the downstream of the plasma of the hydrogen-containing gas. ₃ It is suggested that the gas to be converted into plasma is not necessarily limited to a mixed gas of hydrogen and water vapor.
[0005]
Furthermore, in 1991 patent application No. 366109, NF was placed downstream of the plasma using a mixed gas in which a trace amount of hydrogen or water vapor was mixed in nitrogen. ₃ It has been shown that the natural oxide film of silicon can also be removed by the catalytic effect of metastable level nitrogen by adding.
[0006]
[Problems to be solved by the invention]
All of these technologies have been invented for the purpose of utilizing the action of hydrogen atoms, but the downstream region where the effects of high-energy particles such as electrons, ions, and short-wavelength photons (ultraviolet rays) can be substantially ignored. A practical method for supplying and utilizing a large amount of hydrogen atoms is only shown when using a plasma in which water vapor or oxygen molecules are mixed into hydrogen molecules. In Japanese Patent Publication No. 7-75229, claim 1 includes an organic compound containing hydrogen and oxygen or an inorganic compound containing hydrogen as a gas to be mixed into hydrogen molecules, and specifically, an alcohol, Organic acid, ether, phosphine (PH ₃ ), Arsine (AsH ₃ ), Borane (BH ₃ ), Diborane (B ₂ H ₆ ), Water vapor (H ₂ O), silane (SiH ₄ ), Ammonia (NH ₃ ). Among these gases, alcohols and organic acids contain oxygen and generate water vapor in a mixed gas plasma with hydrogen. Since other silanes, phosphines, and the like are reducible by themselves, it is doubtful how much of the reduction action that occurs downstream of the gas plasma to which they are added is caused by hydrogen atoms. For example, U.S. Pat. S. P. In 5403436, the surface is cleaned by the reducing action of germane mixed in hydrogen. Among them, ammonia is known per se as a reducing gas.
[0007]
It is well known that ammonia is synthesized when a mixed gas of hydrogen molecules and nitrogen molecules is converted to plasma. At that time, the mixing ratio of hydrogen molecules and nitrogen molecules used for efficient ammonia synthesis is Often, the composition ratio is around 3: 1. According to FIG. 3 of Japanese Patent Publication No. 7-75229, the hydrogen atom concentration in the hydrogen molecule-nitrogen molecule mixed gas plasma is approximately 25% of the nitrogen molecule concentration in the mixed gas, that is, the mixing ratio of hydrogen molecules to nitrogen molecules. Is highest when 3: 1. Therefore, if ammonia has an effect of effectively transporting hydrogen atoms to the downstream basin, the mixing ratio of hydrogen molecules to nitrogen molecules is probably one even if the nitrogen concentration in the mixed gas is slightly deviated around 25%. It is envisioned that a high concentration of hydrogen atoms can be obtained in the downstream region when there is probably a lot of hydrogen in a digit ratio. However, according to FIG. 1 of Japanese Patent Application No. 366109 in 1997, the etching amount of the silicon oxide film considered to be caused by the reaction between hydrogen atoms and nitrogen trifluoride is when the hydrogen concentration in the mixed gas is 10% or less. Is getting bigger. In fact, using the experimental apparatus shown in FIG. 1, calorimetric method (Young C. Kim and Michel Board, “Recombination of O, N, and H Atoms on Silica: Kinetics and Machinery, Langmuir, 1999, 1999-300 ( ) And L. Robin Martin, “Diamond film growth a flowtube: A temperature dependency study”, J. Appl. Phys., 70, 5667-5673 (1991)). When the atomic concentration is measured, as shown in FIG. 2, when the concentration of hydrogen molecules in the mixed gas is 20% or less, the downstream The concentration of hydrogen atoms rapidly increases and reaches a maximum in the downstream when the hydrogen molecule concentration is 2%, which means that the hydrogen atom transport mechanism in the hydrogen-nitrogen system is a hydrogen-steam system. This shows that ammonia is not effective in transporting hydrogen atoms to the downstream region like water vapor, and in Japanese Patent Publication No. 7-75229, the processing in the downstream is shown in FIG. 5 (b) and its description only, it is the water vapor that transports the hydrogen atoms again, and similarly used in Japanese Patent Laid-Open No. 6-338478 to transport the hydrogen atoms to the downstream region. Only molecules that contain water vapor or oxygen atoms as constituents.
[0008]
By the way, when molecules having oxygen atoms including water vapor as components are mixed with hydrogen molecules for the purpose of transporting hydrogen atoms to the downstream region, oxygen atoms or hydroxyl groups (OH) are inevitably present in the mixed gas plasma. ) And the like are generated. These oxidizing particles reach the downstream region and oxidize the workpiece surface. J. et al. Kikuchi, S .; Fujimura, M .; Suzuki, and H.M. Yano, “Effect of H ₂ Oon atomic hydrogen generation in hydrogen plasma ", Jpn. J. Appl. Phys., 32, 3120-3124 (1993) has oxygen atoms and hydroxyl groups downstream of the hydrogen-water vapor mixed gas plasma even if the water vapor concentration is 5%. In addition, Jun Kikuchi, doctoral dissertation "Study on dry cleaning technology of silicon surface in integrated circuit manufacturing process" (Kyoto University, 1997), Chapter 4, the natural gas is downstream of the mixed gas plasma of hydrogen and water vapor. It is shown that the surface is oxidized when a hydrogen-terminated silicon substrate not covered with an oxide film is installed. Therefore, a method for performing surface treatment without the influence of high-energy particles and the influence of oxygen atoms or molecules containing oxygen atoms as constituent elements and effectively utilizing the action of hydrogen atoms is disclosed in Japanese Patent Publication No. 7-75229 and It is difficult to know from JP-A-6-338478.
[0009]
Nevertheless, since the nitrogen-hydrogen mixed gas containing 5% or less of hydrogen shown in the 1997 patent application No. 366109 does not contain oxygen in its constituent elements, hydrogen atom treatment avoiding the influence of oxygen is possible. is there. However, using the apparatus shown in FIG. 1, when comparing the hydrogen atom concentration in the downstream region when using a nitrogen-hydrogen mixed gas and the hydrogen concentration in the downstream region when using a hydrogen-water vapor mixed gas, As shown in FIG. 3, the concentration of hydrogen atoms obtained in the downstream region is, for example, about 1/5 lower in the case of a mixed gas of hydrogen molecules and nitrogen molecules than in the case of a hydrogen molecule-water vapor mixed gas. That is, when utilizing the direct action of hydrogen atoms on the workpiece, the hydrogen-nitrogen system is expected to be much less efficient than the hydrogen-steam system.
[0010]
[Means for Solving the Problems]
In order to perform surface treatment without the influence of high-energy particles and the influence of oxygen atoms or molecules containing oxygen atoms as constituent elements, and effectively utilizing the action of hydrogen atoms, at least hydrogen atoms as constituent elements A gas containing molecules and halides is converted into plasma, and a workpiece placed downstream of the plasma is processed.
[0011]
In order to transfer and use hydrogen atoms having a concentration equal to or higher than that of a hydrogen-water vapor mixed gas in the downstream region without being affected by oxygen atoms or molecules containing oxygen atoms as constituent elements, for example, water vapor It is only necessary that the role of can be substituted with molecules that do not contain oxygen as a constituent element. For this purpose, it is necessary to know the mechanism of transport of hydrogen atoms to the downstream region by the hydrogen-water vapor mixed gas plasma. However, both Japanese Patent Publication No. 7-75229 and JP-A-6-338478 describe the mechanism of hydrogen atom transport. There is no. However, J.H. Kikuchi, S .; Fujimura, M .; Suzuki, and H.M. Yano, “Effect of H ₂ O on atomic hydrogen generation in hydrogen plasma ", Jpn. J. Appl. Phys., 32, 3120-3124 (1993), and the temperature of quartz constituting the reaction vessel is not permanent. It is suggested that water molecules physically adsorbed on the quartz surface prevent recombination of hydrogen molecules on the quartz surface, which is a polar molecule. Oxygen in the molecule is negatively charged, while quartz (SiO ₂ ) And alumina (Al ₂ O ₃ ) Is also polarized, for example SiO ₂ Then, Si is slightly positive and oxygen is slightly negative. Therefore, when water molecules are physically adsorbed on the quartz surface, it is assumed that oxygen in the water molecules is adsorbed on Si of the quartz, and hydrogen in the water molecules protrudes upward. Of course, the hydrogen in the water molecule is SiO ₂ An adsorption form approaching the oxygen atom is also conceivable, but in that case, heavy oxygen will be located above, and it is expected that it will become unstable in terms of energy.
Therefore, it is inferred that the quartz surface is covered with adsorbed water molecules downstream of the hydrogen-water vapor mixed gas plasma, and the hydrogen atoms in the water molecules are located on the outermost surface. The validity of this hypothesis is not proved in the text, but it is true that the molecular polarization greatly affects the adsorption of molecules to the solid surface. As long as it has been suggested that an atomic transport effect is brought about, a hydride having strong polarization is expected to be a substitute for water vapor.
[0012]
FIG. 4 shows the result of measuring the concentration of hydrogen atoms in the downstream region by the calorimeter method by flowing a mixed gas of hydrogen molecules and hydrogen chloride (HCl) into the apparatus of FIG. FIG. 5 shows chlorine molecules (Cl ₂ ). In both cases, the hydrogen atom concentration in the downstream region is greatly increased compared with the case of using only hydrogen molecular gas, and the degree is comparable to the case of adding water vapor. In the case of non-polarized chlorine molecules, the same effect as hydrogen chloride can be obtained with H ₂ + Cl ₂ This is because HCl is generated in the plasma, and oxygen molecules have the same effect as water vapor.
[0013]
FIG. 6 shows nitrogen trifluoride (NF) ₃ ) Is the hydrogen atom concentration in the downstream region. Here, the same effect as in the case of hydrogen chloride, chlorine molecules, and water vapor is obtained. This is also considered to be a hydrogen atom transport action due to the generation of strongly polarized hydrogen fluoride (HF) molecules in the plasma. However, when fluorine-containing molecules are turned into plasma, quartz is etched at a considerable rate by the generated fluorine atoms and fluorine ions, so oxygen discharged from the quartz contributes to hydrogen atom transport here. Some parts are also included.
[0014]
From the above results, it can be considered that a hydrogen atom molecule or a gas capable of generating a hydrogen halide molecule in plasma has an effect of transporting hydrogen atoms to the downstream region.
[0015]
Now, U.I. S. P. In 5403436, HCl, HBr, or HF is mixed with hydrogen molecular gas to form plasma, and the surface of the workpiece is dry-cleaned downstream thereof, or those gases separately introduced to the surface of the workpiece placed downstream of hydrogen molecular plasma are introduced. A method of dry cleaning by simultaneous irradiation is described. However, in the case of HCl or HBr as the amount to be mixed, 12000 sccm of H ₂ 50 sccm or less for HF, 12000 sccm for HF ₂ In contrast, 10 sccm or less is desirable. That is, in the case of HCl or HBr, 0.42% or less is preferable, and in the case of HF, 0.083% or less is preferable. However, as can be seen from FIG. 3, a very small amount of HCl of about 0.42% can hardly be expected to transport hydrogen atoms. Moreover, FIG. 6 shows NF ₃ But not HF, but NF in plasma ₃ Since most of the fluorine atoms generated from the hydrogen will reach the hydrogen concentration measurement point and react with hydrogen to form HF, ₃ Even if the dissociation rate in the plasma is 10%, about 0.08% HF is about 0.27% NF. ₃ Should be generated. (10% NF ₃ It is assumed that three Fs are dissociated from each other to form three HFs. ) However, NF is still so small ₃ Addition has no significant hydrogen atom transport effect. Furthermore, U.S. Pat. S. P. 5403436 recommends sapphire instead of quartz as a reactor constituting material for the purpose of avoiding damage to the apparatus. However, although the reason is unknown, for example, in the case of a hydrogen-water vapor mixed gas, when sapphire is used as a reactor material, hydrogen atoms are hardly transferred to the downstream region. Therefore, U. S. P. The recommended process of 5403436 is a range where hydrogen atoms cannot be used. S. P. It is difficult to analogize the effect of the halogen of the present invention from 5403436. In fact U. S. P. 5403436 describes that HCl and HF are mixed with the expectation of a direct effect of the gas on the workpiece surface, such as removal of contaminating metals in the case of HCl. The effect is not touched at all.
[0016]
Therefore, the effect of molecules containing oxygen atoms or oxygen atoms as a constituent element can be obtained by plasmaizing at least a molecule containing hydrogen atoms and a gas containing a halide and processing a workpiece placed downstream of the plasma. It is possible to perform plasma downstream processing utilizing the effect of hydrogen atoms while reducing or eliminating the above. In the plasma generator, the reactor inner wall constituent material may be mixed into the trace plasma by sputtering or the like due to the collision of high energy particles in the plasma, but the surface in contact with the plasma in the reactor for plasma generation is nitrided. By using silicon, it is possible to prevent oxygen from the reactor constituting material from being mixed into the plasma. As a specific method, the plasma contact part itself of the reactor may be made of silicon nitride, or the plasma contact part may be made of quartz or alumina (including sapphire) coated with silicon nitride by a CVD method or the like.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The apparatus shown in FIG. 7 is an apparatus for performing practical processing. Reference numeral 11 denotes a plasma generation chamber used for converting a gas into plasma, which is made of, for example, quartz, alumina, or silicon nitride. In the case of quartz or alumina, the inner wall may be covered with silicon nitride. Reference numeral 12 denotes a gas A supply device, and reference numeral 13 denotes a gas B supply device, each of which includes a flow controller, a valve, a filter, and the like. The gas C supplied from the gas A supply device 12 and the gas B supply device 13 is supplied to the plasma generation chamber 11 via the joint 14. A nozzle 18 for adding gas is provided downstream of the plasma generation region of the plasma generation chamber 11, and the gas D is added to the plasma downflow region from the gas D supply device 19 through the joint 20. Can do. The gas D supply device 19 includes a mass flow controller, a valve, a filter, and the like. The plasma generation chamber 11 is connected to the processing chamber 22 via an O-ring 21. The workpiece 23 is placed in the processing chamber 22, and the workpiece surface is treated with a gas obtained by adding the gas D to the plasma mixed gas C. The workpiece 23 is placed on a stage 24, and an SiC heater 25 for heating the workpiece is attached to the top of the stage 24. The processing chamber 22 is provided with an exhaust port 26 for exhaust. Although not shown, a rotary pump is connected to the processing apparatus. Further, an inner wall 28 may be provided in the processing chamber for the purpose of protecting the processing chamber wall surface.
[0018]
【Example】
[First Example] Using the apparatus of FIG. 7, a mixed gas of 90 sccm of hydrogen molecules and 10 sccm of chlorine molecules is converted into plasma by applying a microwave of 500 W, 2.45 GHz, and NF is downstream thereof. ₃ Is added, and a 6-inch silicon wafer with a natural oxide film is further installed downstream and processed under conditions of a processing pressure of 2 Torr and a processing time of 3 minutes. As a result, the silicon wafer surface becomes water-repellent and the natural oxide film is removed. Was confirmed.
[0019]
Similarly, a mixed gas of 90 sccm of hydrogen molecules and 10 sccm of hydrogen chloride is converted into plasma by applying a microwave of 500 W and 2.45 GHz, and NF is downstream of it. ₃ Even when 100 sccm is added and a 6-inch silicon wafer with a natural oxide film is further installed downstream and processed under conditions of a processing pressure of 2 Torr and a processing time of 3 minutes,
It was confirmed that the silicon wafer surface was water-repellent and the natural oxide film was removed.
[0020]
Second Example Using the apparatus of FIG. 7, a mixed gas of hydrogen molecules and chlorine molecules (H ₂ Flow rate 90sccm, Cl ₂ A flow rate of 10 sccm is converted into plasma by applying a microwave of 500 W and 2.45 GHz, and silane (SiH) is formed downstream of the plasma. ₄ ) 5 sccm of gas was added, and a silicon wafer in which the surface placed on the downstream stage was covered with a silicon oxide oxide film was processed. When the temperature of the silicon wafer was set to 450 ° C. and treated under a pressure of 2 Torr for 1 hour, the formation of deposits was observed on the wafer. The wafer surface immediately after processing became water-repellent. From this, it is considered that the deposit was silicon.
[0021]
[Third embodiment] Using the apparatus shown in FIG. ₂ Flow rate 90sccm, Cl ₂ Plasma was applied at a flow rate of 10 sccm) by applying a microwave of 500 W and 2.45 GHz, 5 sccm of ethyl alcohol was mixed downstream thereof, and the silicon wafer was heated to 700 ° C. and processed for 3 hours. It was confirmed that the wafer surface was discolored and deposits were formed. The identity of the deposit was inferred by oxygen plasma treatment. A barrel type oxygen plasma ashing apparatus used for oxygen plasma treatment is shown in FIG. In this apparatus, oxygen is allowed to flow through the quartz reaction tube 31, and RF supplied from the high frequency power supply 33 is applied to the electrodes 32a and 32b to generate oxygen plasma, thereby processing the wafer 35 placed on the wafer carrier 34. . The wafer 35 is taken in and out from the opening on the end face of the quartz tube 31, and the opening is sealed with a cover 36 when processing is performed. Further, an aluminum etch tunnel 37 may be installed in the reaction tube 31. In such a barrel-type oxygen plasma ashing apparatus, O ₂ When the above wafer was processed for 30 minutes under the conditions of 1 Torr and RF output of 300 W, the color of the surface of the silicon wafer returned to that of the original silicon, and it is considered that the deposit was almost removed. From this, it was expected that the deposit was a carbon-based material such as amorphous carbon, diamond-like carbon, etc., indicating that this method can be applied to the production of a carbon-based film containing diamond.
[0022]
[Fourth Embodiment] Using the apparatus of FIG. 7, a mixed gas of hydrogen molecules and chlorine molecules (H ₂ Flow rate 90sccm, Cl ₂ A flow rate of 10 sccm) is applied to a plasma of 500 W and 2.45 GHz, and a 10-yen coin and iron piece whose surface is oxidized and loses its glossiness are placed downstream, a processing pressure of 2 Torr and a processing time of 3 minutes. As a result, the metallic luster revived on both the 10-yen coin and the iron piece. This shows that the metal oxide film on the metal surface has been removed or reduced.
[0023]
【The invention's effect】
As described above, oxygen atoms or oxygen atoms are included as components by converting a gas containing at least a molecule containing hydrogen atoms and a gas containing a halide into plasma and processing a workpiece placed downstream of the plasma. Plasma downstream processing using the effect of hydrogen atoms while reducing or eliminating the influence of molecules has become possible. In particular, if silicon nitride is used as the surface in contact with the plasma of the reactor for generating plasma, it is possible to prevent oxygen from being mixed into the plasma from the reactor constituent material. Although it could not be confirmed due to the above problem, there is a possibility that epitaxial growth of silicon and amorphous silicon film in which a serious deterioration in film quality occurs even with a small amount of oxygen can be performed at a low temperature of 650 ° C. or less where dopant in silicon does not diffuse much. Yes, the path to quantum device fabrication has opened.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an experimental system for evaluating a hydrogen atom concentration in a plasma downstream region.
FIG. 2 is a graph showing the dependence of the hydrogen atom concentration in the downstream of the nitrogen-hydrogen mixed gas plasma on the flow rate ratio of nitrogen and hydrogen.
FIG. 3 is a diagram showing a comparison between a hydrogen atom concentration in a downstream region when a nitrogen-hydrogen mixed gas is used and a hydrogen concentration in a downstream region when a hydrogen-water vapor mixed gas is used.
4 is a diagram showing a result of measuring a hydrogen atom concentration in a downstream region by a calorimetric method by flowing a mixed gas of hydrogen molecules and hydrogen chloride (HCl) into the apparatus of FIG. 1 to generate plasma.
5 shows a hydrogen molecule and a chlorine molecule (Cl ₂ The gas mixture was made to flow into a plasma and the hydrogen atom concentration in the downstream region was measured by a calorimetric method.
FIG. 6 shows nitrogen trifluoride (NF) ₃ ) Is made into plasma by flowing a mixed gas, and the hydrogen atom concentration in the downstream region is measured by a calorimetric method.
FIG. 7 is a diagram showing an apparatus for performing a practical process of the present invention.
FIG. 8 is a view showing a barrel type oxygen plasma ashing apparatus used for oxygen plasma treatment.
[Explanation of symbols]
1 Gas inlet
2 Waveguide
3 Plasma generator
4 chambers
5 Exhaust port
6 Thermocouple
11 Plasma generation chamber
12 Gas A supply device
13 Gas B supply device
14 Fitting
15 Waveguide
16 Plasma generator
17 chamber
18 nozzles
19 Gas D supply device
20 Fitting
21 O-ring
22 treatment room
23 Workpiece
24 stages
25 SiC heater
26 Exhaust vent
27 Loading / unloading port
28 inner wall
31. Quartz reaction tube
32a, 32b electrode
33 High frequency power supply
34 Wafer carrier
35 wafers
36 Cover
37 Aluminum Etch Tunnel

Claims (6)

In a surface treatment method in which a molecular gas containing hydrogen atoms as a constituent element is turned into plasma, and a workpiece placed downstream of the plasma is treated using the action of hydrogen atoms.
As an additive for effectively transporting the hydrogen atoms generated by the plasma downstream, at least one compound molecule of a hydrogen chloride molecule or a hydrogen bromide molecule is added to a molecular gas containing the hydrogen atom as a constituent element. Adding gas containing,
The flow rate of the compound molecule is such that the amount of hydrogen atoms contained in the molecule is greater than 1/480 with respect to the amount of hydrogen atoms contained in the gas other than the compound molecule in the entire gas subjected to the plasma treatment. The surface treatment method characterized by being set to . The surface treatment method according to claim 1, wherein the at least one compound molecule is a compound molecule that does not contain oxygen as a constituent element. In a surface treatment method in which a molecular gas containing hydrogen atoms as a constituent element is turned into plasma, and a workpiece placed downstream of the plasma is treated using the action of hydrogen atoms.
As an additive for effectively transporting the hydrogen atoms generated by the plasma downstream, at least one selected from the group consisting of chlorine, bromine and iodine is added to the molecular gas containing the hydrogen atoms as constituent elements. Add at least one gas as a component,
In the middle of transporting the hydrogen atoms generated by the plasma downstream, gas for processing the workpiece is mixed under the action of the hydrogen atoms.
A surface treatment method characterized by the above .   The surface treatment method according to claim 3, wherein the gas for treating the workpiece includes molecules containing silicon as a constituent element.   The surface treatment method according to claim 3, wherein the gas for treating the workpiece includes molecules containing carbon as a constituent element.   The surface treatment method according to claim 3, wherein the gas for treating the workpiece includes molecules containing fluorine as a component.

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