Method and apparatus for forming a film

Abstract: This invention relates to a method and an apparatus for forming a film, which are suitable for forming a film of a semiconductor, dielectric, metal, insulator, or organic substance. In order to form a film (17) of high purity and quality at high speed, a particle beam (16) such as an ion beam, an electron beam, or a plasma is applied to a sputtering target (9) comprising a substance formed by bonding atoms or molecules with either van der Waals forces or hydrogen bonding forces, the particles are sputtered thereby from the target (9), fly in the space in the vacuum chamber (7), reach the substrate on which they are deposited to form a desired film (17). To form an organic film free of pinholes, impurities, or disorder in the molecular composition and arrangement in a large area at high speed, a particle beam (16) of about 10 eV or less is applied to the target (9) comprising an organic compound disposed in a vacuum. The particle beam (16) has energy high enough to break the van der Waals bonds between the molecules of the organic substance but not the covalent bonds between the atoms. The sputtered particles from the target (9) are deposited on the substrate (10) to form a film (17) of the organic compound.

Description: BACKGROUND OF THE INVENTION This invention relates to a method and an apparatus for forming a film and more particularly to a method and an apparatus suitable for forming a film of semiconductor, dielelctric, metal, insulator, or organic substance. It is well known that sputtering is conventionally used for forming a film of metal or dielectric material. As discussed in pages 171 to 195 of "Hakumaku (Thin Film) Handbook" edited by Japan Society for the Promotion of Science (published by Ohmsha, Ltd., December 1983), there is a wide range of methods which include DC diode sputtering, bias sputtering, radiofrequency (RF) sputtering and magnetron sputtering, the last one being intended for high-speed film formation. In addition, an ion beam sputter deposition method is also known, which is described in pages 190 and 191 of the above-mentioned literature. All of these methods utilize sputter ejection of atoms from a substance in the solid state at room temperature which occurs when it is struck by an ion beam or ions in the plasma. In this case, the sputtering mechanism is explained by collision cascade model. Therefore, the film forming speed is limited by the sputtering rate of a substance in the solid state. On the hand, sputtering is achieved by ion irradiation of a substance in the solidified state made by cooling a gas of carbon monoxide, methane, etc. and combing their molecules by van der Waals forces. As an example, this sputtering method is discussed in "Desorption Induced by Electronic Transition DIET II" pp. 170-176 (compiled by W. Brening, D. Menzel, published by Springer, 1985) and in "Sputtering of Frozen Gases" by J. Schon in Nuclear Instruments and Methods in Physics Research, Vol. B27 (1987) June (II) No. 1, pp. 188-200. These documents focus on the etching of the target by the sputtering, and the disclosed sputter-conditions are not optimised for use of the sputtering in the formation of films. In this case, it is known that the number of atoms and molecules which are decomposed per incident ion by sputtering of a solidified substance of a gas of carbon monoxide or methane, that is to say, the sputtering yield is about 100 to 1000. Japanese Patent Application JP-A-63-177414 discloses a method in which laser light is irradiated on a gas or a solidified substance to quickly impart energy to this substance in order to heat it and convert it into a plasma and a film is formed by using particles produced in the plasma. Among the prior-art techniques, the sputtering method employing ions and a plasma uses a substance in the solid state at room temperature as a target material for sputtering and forms a film by sputtered particles which are decomposed and sputtered by a sputtering mechanism described in pages 171 to 179 of the above-mentioned "Thin Film Handbook". In this case, the sputtering yield of the target per ion incident on the target is 1 to 10. Accordingly, the problem with this method is the slow film forming speed of 0.1 to 1 nm/sec. In principle, the purity of the deposited film never becomes higher than that of the target for sputtering. When a high-purity target for sputtering is not available, you can obtain only a film of poor quality which contains impurities, which has been another problem. In a film forming method using a laser-induced plasma, the mechanism whereby plasma particles are produced is such that the target absorbs the energy of photons. Therefore, the kinetic energy of a plasma particle thus produced is smaller than that of a particle sputtered from the target by irradiation by ions having large momentum. For this reason, the deposited film is inferior in adhesion strength to those which are formed by the conventional sputtering methods in which irradiation by ions having large energy is used. Meanwhile, in depositing an organic film, the wet process has been used chiefly. The feature of this wet process is that a relatively uniform film is formed easily as in the spin coating method and the cast method. Therefore, the wet process is superior in productivity and is applied extensively in film forming processes such as applying a photoresist for photolithography, an insulating film between layers of a semiconductor element, or a liquid crystal arrangement control film of a liquid crystal display element. In contrast to the foregoing, the vacuum evaporation technique is a dry process in film deposition. There was a report on the formation of an organic single crystal film in "Journal of Applied Physics", volume 36, number 4, April 1965, pp. 14531460. According to this method, it is possible to form a film with superior crystallinity and orientation. The plasma polymerization method is another film forming technique by a dry process. For example, a report on a metallic phthalocyanine plasma-polymerized film was carried by "Journal of the Chemical Society of Japan, No. 11 (1987), pp. 2019-2024. By this method, it is possible to form not only a functional film with an ability of photoelectric conversion, etc., but also a film generally superior in mechanical strength and heat resistance. In the meantime, the organic film forming method by a wet process has mass-production aptitude and is currently the best film forming method. However, considering technical requirements for an organic film forming method to be used for the development of the next-generation devices, there are some requirements which are hard to meet by the conventional wet processes. For example, the liquid crystal display needs to meet requirements for further microminiaturization, color display and an enlarged screen. Efforts are being actively exerted to develop a liquid crystal display by the active matrix method, which combines display elements and a driving circuit. In one display, there are tens of thousands to hundreds of thousands of transistors formed on a glass plate several tens of centimeters square. Therefore, it is required to form a uniform photoresist film in the transistor manufacturing process. In the spin coating method, to secure a uniform film thickness, the substrate is rotated at about 3,000 revolutions per minute and a photoresist is applied thereto. As the substrate increases in size, the edges of the substrate turns at a high speed so high as to approach the speed of sound. By technology at the moment, it is impossible to rotate and hold a substrate stably and apply the resist uniformly. With regard to an insulating film between the layers of a semiconductor element, a problem with the wet process has been pointed out. A polyimide film for use as an insulating film is conventionally made as follows. A diamino compound and tetracarboxylic acid (or its derivative) are polymerized in an organic polar solvent to make a polyamide acid varnish. The polyamide acid varnish is spread across the substrate, then the substrate is heated and dried to obtain a polyimide layer formed on the surface. (Refer to JP-B-36-10999, for example.) With growing needs for higher integration of semiconductor devices as the backdrop, it is required to provide sufficient insulation performance with a film about 1 µm thick. The method mentioned above is unable to eliminate pinholes completely. There is also a problem that mixing-in of impurities is liable to occur. Therefore, a film that can withstand practical application has not been realized by this method. An organic lubrication layer is formed, unquestionably, by a wet process, to prevent the wear of the surface of the magnetic disk. In order to respond to the needs for an improvement in recording density, the magnetic recording layer, which used to be formed by a wet process, has come to be formed by a dry process. Accordingly, it has become necessary to adopt a dry process for the formation of a lubrication layer to maintain the quality of the film formed and enhance the efficiency of film formation. In forming an organic film by a dry process, which is to replace the wet process, the vapor evaporation method and the plasma polymerization method have advantages as described above. However, the former method has problems that it is difficult to form a film with a large area, that the film forming speed is slow, and that the number of substances that can be used for vacuum evaporation is limited (for example, the substances which are subject to a polymerization reaction when they are heated for evaporation cannot be used). In the latter method, disorder is liable to occur in the molecular composition and arrangement, and it is difficult to control the molecular chain orientation. Different experiments for depositing organic polymer films by sputtering are reported in J.S. Sovey: "Ion beam sputtering of fluorpolymers" in Journal of Vacuum Science and Technology, Vol. 16 (2), Mar./Apr. 1979, pp. 813- 816, and in JP-A-61-183459. In these experiments, the targets are composed of substances which are solid at ambient temperature. During sputtering, the target temperature rises to temperatures close to or above the melting point of the substance. The first-mentioned document reports particle energies of primary ions used for sputtering between 250 and 1000 eV. SUMMARY OF THE INVENTION It is an object of the invention to provide a method and an apparatus for forming an organic film of high quality at high speed. This object is solved by the method set forth in claim 1 and the apparatus of claim 15. The subclaims are directed to preferred embodiments of the invention. An embodiment consists in applying a particle beam such as an ion beam, electron beam or plasma to a sputtering target formed of a substance made by bonding of atoms and molecules by either van der Waals forces or hydrogen bonding forces in a vacuum, and having the particles dislodged from the target, sputter in the space within the chamber to the substrate on which the sputtered particles are deposited to form a desired film. As for the sputtering target in this embodiment, a substance, which is in a gaseous or liquid state at normal temperature and pressure, is solidified by cooling it to below its melting point, for example, and used as a sputtering target. More specifically, in a conventional sputtering deposition method, a substance, formed of atoms and molecules strongly bonded together by metallic bond, ionic bond or covalent bond at normal temperature and pressure, is used for a sputtering target, and therefore, the sputtering yield has been low. In this embodiment, on the other hand, a substance weakly bonded by either van der Waals forces or hydrogen bonding forces is used for the sputtering target. Therefore, the sputtering mechanism when ion irradiation is performed on the target differs from the prior art, with the result that the number of sputtered particles per ion is as large as 100 to 1000, making high-speed film formation possible. Another embodiment consists in applying a particle beam to a target of an organic compound in a vacuum, said particle beam having a level of energy as high as can break the molecular crystalline bonds and not so high as can break the nonmolecular crystalline bonds, the molecular crystalline bonds consisting of van der Waals forces connecting the atoms constituting the organic compound and the non-molecular crystalline bonds consisting of covalent bonds, for example, other than van der Waals forces, said particle beam having an energy less than about 10 eV, and depositing the sputtered particles from the target onto the substrate facing the target, thereby forming a desired film of an organic compound. To be more specific, when the target formed of the organic compound mentioned above is struck by a particle beam having a predetermined energy described above, out of the molecular crystalline bonds of van der Waals forces connecting the atoms constituting the organic compound and the nonmolecular crystalline bonds other than van der Waals forces such as the covalent bond (these bonds are sometimes collectively referred to as nonuniform bond type molecular crystals), only the molecular crystalline bonds are broken and the molecules connected by the nonmolecular crystalline bonds are ejected by sputtering. Some of the sputtered particles reach the substrate, and molecular crystalline bonds are formed again, thus forming an organic compound film. In an ordinary sputtering film formation, a particle beam of 500 electron volts to several kilo-electron volts strikes the target. Therefore, many of the bonds of the molecules in the organic compound are broken and the target is carbonized. This makes it difficult to form an organic compound on the substrate. In the method according to the present embodiment, however, the particle beam that strikes the target is extremely low at about 10 eV, and therefore, there is no problem of carbonization of the material substance. In addition, the disorder in the molecular composition or the like in the deposited film is very small. Since the molecules that scatter by sputtering each have an energy of one to several electron volts, a dense film can be formed, and there are less chances for pinholes to occur or for impurities to enter. Furthermore, in this invention, the molecular crystalline bonds are broken by irradiation of the particle beam to cause sputtering. As a result, the sputtering yield is fairly high compared with the prior-art methods, so that a film can be formed at high speed. BRIEF DESCRIPTION OF THE FIGURES Fig. 1 is a construction diagram showing an apparatus used for film formation according to an embodiment of the present invention; Figs. 2, 3 and 4 are construction diagrams showing organic film forming apparatuses capable of controlling the pressure and temperature of a material substance; Figs. 5A, 5B and 5C are construction diagrams of the material substance blowout outlet of the apparatuses of Figs. 2 through 4; Fig. 6 is a construction diagram of a large-area organic film forming apparatus according to an embodiment of the present invention; Fig. 7 is a diagram for explaining the operation of Fig. 6; Figs. 8, 9 are arrangement diagrams showing a large-area organic film forming apparatus according to another embodiment of the present invention. DESCRIPTION OF PREFERRED EMBODIMENTS Fig.1 is a diagram showing a construction of an apparatus for forming a fluorine-containing polymer film on an aluminum substrate. As shown in Fig. 1, in a vacuum chamber 7, there are provided a gas supply pipe 8, a cooling head 9, a substrate 10a attached to a substrate holder 11, a heater 14 for heating the substrate, an ion source 12, and a laser light generator 233. The vacuum chamber 7 is evacuated to about 1.3·10 -5 Pa (1 × 10 -7 Torr) by vacuum pump (not shown) through an exhaust port 230. The cooling head 9 can be cooled to the temperature of liquid nitrogen. The laser light generator 233 is a pulse-operated CO 2 laser and outputs a maximum of 1 joule. A film forming operation was performed as follows. A mixed gas of CHF 3 and C 2 F 2 was introduced through the gas supply pipe nozzle 8 onto the cooling head 9 cooled to the temperature of liquid nitrogen, where a solidified layer 235 was formed which was used as the target. An argon ion beam 16 of about 6 to 10 eV generated by an ion source 12 was applied to a solidified layer 235 and also, an infrared laser light 234 of a wavelength of 10.6 pm and as much as 0.5 joule was applied to the solidified layer 235, whereby particles (molecules) were sputtered. Part of the particles 231 are deposited on a mirror-finished 12.7 cm (5-in.) aluminum substrate (1 mm thick) 10a held at 100°C, thus forming a thin film. A film with a thickness 10 nm (100 Å) was formed for the following evaluation test. The laser light 234 was applied to facilitate the production of radicals. Even if the laser light 234 is not applied, a film can be formed, but in that case, the film forming speed decreases. The thus formed film was assumed to comprise crosslinked polymers. The ratio of the constituent elements was 34.8% C : 12.3% H : 52.6% F. The film forming speed was 50 nm/min. The aluminum substrate coated with this fluorine-containing polymer film was subjected to a lubrication performance test by a pin-on-disk wear tester. By using a 30-mm diameter spherical sapphire pin, the surface of the specimen was inspected after 20000 revolutions under the condition of 20 g load and 20 m/s peripheral speed. It was confirmed that the lubricating layer had not been damaged, and it became clear that the this film had an excellent lubricating performance. It was also recognized that this film had good corrosion resistance. For comparison sake, by using the same mixed gas as in the present embodiment, a film was formed by the plasma polymerization method. The film obtained was found to be crosslinked three-dimensionally, and it exhibited a good lubricating performance, but had susceptibility to corrosion. The film forming speed was about 35 nm/min. According to this invention, by applying ions with low energy to a solidified layer of a mixed gas of HCF 3 and C 2 F 6 , a film of chainlike crosslinked polymers can be formed on the substrate, and this film shows good sliding performance. In addition, the film formation in the present invention ensures better corrosion resistance and higher film forming speed than in the conventional plasma polymerization method which uses the same gas mixture. In the above description of the film formation by an apparatus shown in Fig. 1, no mention has been made of the conditions of pressure and temperature of the material substance to be used for forming a film. They will now be described in detail. Fig. 2 is a diagram showing the construction of a film forming apparatus capable of controlling the pressure and temperature of a material substance. As shown in Fig. 2, an ion source 12 is fitted to a vacuum chamber 7, and in the vacuum chamber 7, there are arranged a substrate 10a attached to a substrate holder 11, a cooling head 9 for forming a solidified layer of a material substance thereon, and a material substance introducing pipe 236 for introducing a material substance which is in gaseous or liquid state at normal temperature and pressure. A material substance is supplied into the material substance introducing pipe 236 by a pressure and temperature control section 238. In the pressure and temperature control section, the pressure of the material substance can be controlled by changing its flow rate, and the temperature of the material substance can be controlled by operating a cooling plate 237 and a heater 239. The apparatus of Fig. 2 operates as follows. A material substance, comprising an organic compound and controlled at predetermined pressure and temperature, is supplied onto the cooling head 9 through the material substance introducing pipe 236. The cooling head 9 is held below the solidifying points of the material substance by a refrigerator (not shown), so that a solidified layer is formed. When an ion beam of about 10 eV produced in the ion source 12 is applied to the solidified layer 235, particles are sputtered from the solidified layer 235, thus depositing a film of an organic compound on the substrate 10a held at a predetermined temperature. If the material substance is a gas, the pressure and temperature control section 238 controls the supply (blowout) speed of the gas so as to be less than sonic velocity. If the gas gushes out at a velocity faster than sonic velocity, shock waves occur inside the vacuum chamber 7, producing unfavorable effects on the formation of a film. It became clear that when the gas blowout speed is slower than sonic velocity, the faster the speed, the more quickly the solidified layer 235 is formed. Therefore, in forming a film, it is desirable to set the optimal gas blowout speed to allow compensation - neither excessive nor insufficient - for the decrease in the solidified layer 235 due to sputtering. Generally, it is better to minimize the difference in temperature between the material substance and the cooling head in order to lessen the effect of the temperature change of the organic compound, which will result in a change in the chemical composition. When a material substance in gaseous state is used, from experience with a certain range of material substances used to date for film formation, a good film can be formed by raising the temperature of a material substance 5 to 10°C higher than its boiling point and then by lowering the material substance temperature on the cooling head to 5 to 10°C lower than its melting point. As a concrete example of material substance, a case in which tetrafluoroethylene (CF 2 = CF 2 ) was used will be described. When the temperature of a material substance is -70°C and the temperature of the cooling head 9 is -150°C, a material substance, the melting point of which is -142.5°C, forms a solidified layer 235. By applying an argon ion beam 16 of about 6 to 10 eV to the solidified layer 235 to sputter particles therefrom, a film was formed on the aluminum substrate 10a held at 100°C. By investigating the constituent element ratio of the deposited film, it was clarified that the film comprised polytetrafluorethylene -CF 2 -CF 2 - n , and that there was no disorder in the chemical composition, which occurred when a film was formed when the temperature of the material substance is room temperature. Fig. 3 is a modification of the film forming apparatus capable of controlling the pressure and temperature of a material substance. This apparatus is the same as the one shown in Fig. 2, excepting that there is further provided an ion source 240 for irradiation of the substrate 10a. By using the apparatus of Fig. 3 and tetrafluoroethylene as the material substance, a film was formed on the aluminum substrate 10a. It was confirmed that the film was polytetrafluoroethylene with less disorder in the chemical composition like the film formed by the apparatus of Fig. 2. Since an argon ion beam 10a of about 5 eV produced in the ion source 240 was applied to the substrate 10a, it became clear that the deposited film was more dense and had better adherence to the substrate 10a than the film formed by the apparatus of Fig. 2. Fig. 4 is another modification of the film forming apparatus capable of controlling the pressure and temperature of a material substance. The apparatus in Fig. 4 is almost identical with the one of Fig. 2, with only the exception that the material substance introducing pipe 236 is adapted to be movable above the cooling head 9. By using this apparatus, the solidified layer can be formed with uniform thickness and the thickness distribution of the film formed by sputtering on the substrate 10a can be made uniform. Figs. 5A, 5B and 5C show a modification of the material substance blowout nozzle of the material substance introducing pipe 236. Fig. 5a shows the nozzle having many holes, Fig. 5B shows the nozzle widened in a taper form to supply the material in a wide range, and Fig. 5C shows the nozzle which has one or more holes and can pivot. By using an apparatus having any of these nozzles for forming a film, the thickness of the deposited film can be made more uniform. As described above, it was confirmed that by the use of the apparatus of Fig. 1, an organic film having good lubricating performance can be formed. To apply this film forming method to an actual manufacturing process, however, it is necessary to develop an apparatus for forming a uniform film over a large area. A large-ares film forming apparatus will be described in the following. With reference to Figs. 6 and 7, the construction and operation of a large-area film forming apparatus will be described. As shown in Fig. 6, in a vacuum chamber 7, there are arranged an ion source 12, an introducing pipe 3 for introducing into a vacuum a material substance in gaseous or liquid state at normal temperature and pressure, a cooling head 4, a filament 14 for heating a substrate, a substrate holder 11, and a substrate 10a. The material substance introducing pipe 3 in a pipe for has a plurality of holes bored at least in a row in the axial direction at the surface of the pipe. The substrate 10a is a rectangular prism (thin in thickness) long in a direction perpendicular to the surface of the paper on which there is Fig. 6. As shown in Fig. 7, the cooling head 4 has a cylindrical form, and it can be cooled to about the temperature of liquid nitrogen and is rotatable about its axis. The vacuum chamber 7 is evacuated to 1.3·10 -5 Pa (1 × 10 -7 Torr) by a vacuum pump (not shown). For example, a mixed gas of HCF 3 and C 2 F 6 is introduced into a vacuum through the material substance introducing pipe 3, and a solidified layer of the mixed gas is formed on the surface of the cooling head 4. An argon ion beam 16 with energy of about 6 to 10 eV is applied to the solidified layer, and sputtered particles 231 are deposited on the aluminum substrate 10a to form an organic film. In this film forming process, though this is not illustrated, if a CO2 laser light is applied to near the above-mentioned solidified layer to promote the production of radicals, the film forming speed can be improved. By using the apparatus of Fig. 6, a film can be formed on a large-area substrate long either in the vertical or horizontal side. Another example of the large-area film forming apparatus will be described with reference to Fig. 8. In this apparatus, there are provided an ion source 12, a material introducing pipe 3, a cooling head 4, and a filament 14 for heating. This arrangement of the parts is the same as in the apparatus of Fig. 6, but only difference is that a substrate 10a has a large area in a generally square shape and is movable in the arrow direction by a substrate feed mechanism 242. In forming a film by this apparatus, a solidified layer of a material substance introduced into a vacuum through the material supply pipe 3 is formed on the surface of the cooling head 4, particles are sputtered by an ion beam from the ion source 12 to form a film on the substrate 10a. This operation is the same as that by the apparatus of Fig. 6. However, in the case of Fig. 8, a film is formed while the substrate 10a is moved in the direction of the arrows, making it possible to form an organic film substantially uniform in quality and thickness even on a large-area substrate on which a square film is to be deposited. In addition, since the cooling head 4 is rotated, the region in which a solidified layer of material substance is formed can be separated from the region to which an ion beam 16 is applied, so that large quantities of ion beam can be applied and the film forming speed can be increased, accordingly. Yet another example of the large-area film forming apparatus will be described with reference to Fig. 9. In the case of this apparatus, in a vacuum chamber 7, there are provided an ion source 12, a material introducing pipe 3, a cooling head 4, a filament 14 for heating, a substrate 10a, and a substrate feed mechanism 242. This arrangement of the parts is the same as in the apparatus in Fig. 8, but only difference is that there are further provided a slit 243 for shaping the sputtered particles and a speed control circuit 245 for changing the feed (moving) speed of the substrate. Also in the film deposition by this apparatus, an ion beam 16 is applied to a solidified layer of material substance formed on the surface of the cooling head 4, and a film is formed by depositing sputtered particles 231 by moving the substrate 10a. This film forming operation is the same as in the apparatus of Fig. 8. However, in this embodiment, the thickness of the film deposited on the substrate 10a can be set arbitrarily by controlling the substrate feed speed by the speed control circuit 245 and using the slit 243. Furthermore, it is possible to selectively form a film only in a specified region on the substrate 10a. These features are useful particularly in the fabrication process of thin film transistors for display units. In the foregoing embodiments, ion beams were used for irradiation of the substrate formed on the surface of a target or a cooling head, but other particle beams such as a neutral particle beam or a plasma may be used. The same effect can be achieved by using the types of particles other than those of argon. The film forming speed differs with the kinds of particles.

Claims: A method for forming a film, comprising the following steps performed in a vacuum chamber (7) : holding a target (13, 235) of an organic compound, which is liquid or gaseous at normal temperature and pressure, in solidified form at a temperature below its melting point, sputtering said target by applying a particle beam (16) having a particle energy high enough to break inter-molecular bonds and not high enough to break intra-molecular bonds of said solidified compound, and holding a substrate (10) so as to deposit thereon particles produced by said sputtering, the deposited particles forming said film. The method of claim 1, wherein said particle energy is about 10 eV or less. The method of claim 1 or 2, wherein said compound is introduced into said vacuum chamber (7) and adsorbed on a target head (9) cooled to below the compound's melting point. The method of claim 3, wherein the introduction of said compound is continued during sputtering to maintain the adsorbed quantity of the compound constant. The method of claim 3 or 4, comprising a step for controlling the temperature of the compound being introduced. The method of any of claims 1 to 5, wherein said compound is held on a target head (4) which is rotated or reciprocated. The method of claim 6, wherein said target head (4) has a cylindrical shape and is rotated while said substrate (10a) is moved in a direction substantially parallel to said target head. The method of any of claims 1 to 7, wherein heat or another exciting beam comprising ions, electrons, radicals and/or light is applied to the substrate (10a). The method of any of claims 1 to 8, wherein at least part of said particles produced by sputtering is ionised by electron impact or laser light means (233, 234) and said film is formed while said ionised particles are applied to the substrate (10a). The method of any of claims 1 to 9, wherein two different compounds which are gaseous or liquid at normal temperature and pressure are introduced into said vacuum chamber (7), a target head (9) in said vacuum chamber is cooled to a temperature lower than the melting point of any of said compounds and a mixture of said compounds is adsorbed on the target head. An apparatus for forming a film in a vacuum chamber (7), comprising a target head (9) for holding a target (13, 235) of an organic compound, which is liquid or gaseous at normal temperature and pressure, in solidified form at a temperature below its melting point, means (12) for sputtering said target by applying a particle beam (16) having a particle energy high enough to break inter-molecular crystalline bonds but not high enough to break intra-molecular bonds of said solidified compound, and a holder (11) for holding a substrate (10) so as to deposit thereon particles (231) produced by said sputtering, the deposited particles forming said film.

Inventors: ARIMATSU KEIJI, ISOGAI MASATO, MIYAKE KIYOSHI, NAKAGAWA YUKIO, NATSUI KENICHI, OHNO YASUNORI, OUHATA KOUKICHI, SEKI TAKAYOSHI, WARABISAKO TERUNORI, ARIMATSU, KEIJI, ISOGAI, MASATO, MIYAKE, KIYOSHI, NAKAGAWA, YUKIO, NATSUI, KENICHI, OHNO, YASUNORI, OUHATA, KOUKICHI, SEKI, TAKAYOSHI, WARABISAKO, TERUNORI, ARIMATSU, KEIJI, 8-6, MIYAKE, KIYOSHI, 9-13, HASHIKABE-2-CHOME, NAKAGAWA, YUKIO, 22-30 HOJO-1-CHOME, NATSUI, KENICHI 18-12, OUHATA, KOUKICHI, 18-13, SEKI, TAKAYOSHI, TOZAWARYO, WARABISAKO, TERUNORI, 2196-143
Applicants: HITACHI LTD, HITACHI, LTD.
Application year: 1990
Main classification: C23C14
IPC codes: C23C14