Silicon nitride film deposition method, organic electronic device manufacturing method, and silicon nitride film deposition device

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in this specification and the drawings, the same reference numerals are given to constituent elements having substantially the same function structure, so that repeated descriptions are omitted.

[0032] First, the manufacturing method of the organic electronic device according to the embodiment of the present invention will be described together with the substrate processing system for implementing the manufacturing method. figure 1 It is an explanatory diagram showing the outline of the configuration of the substrate processing system 1. figure 2 It is an explanatory diagram showing the manufacturing process of an organic EL device. In addition, in this embodiment, a case where an organic EL device is manufactured as an organic electronic device will be described.

[0033] Such as figure 1 As shown, a cluster substrate processing system 1 has a transfer chamber 10. The transfer chamber 10 has, for example, a substantially polygonal shape (hexagonal shape in the example shown) in a plan view, and the inside can be sealed. Around the transfer chamber 10, a load lock chamber 11, a cleaning device 12, a vapor deposition device 13, a sputtering device 14, an etching device 15, and a plasma film forming device 16 are sequentially arranged in a clockwise direction when viewed from above.

[0034] A multi-articulated transport arm 17 capable of telescoping and rotating is provided inside the transport chamber 10. By this transfer arm 17, the glass substrate as a substrate is transferred to the load lock chamber 11 and each processing apparatus 12-16.

[0035] The load lock chamber 11 is a vacuum transfer chamber that maintains the inside of the glass substrate transferred from the atmospheric environment (system) to the transfer chamber 10 in a reduced pressure state and maintains the inside in a predetermined reduced pressure state.

[0036] In addition, the configuration of the plasma film forming apparatus 16 will be described later. In addition, the cleaning device 12, the vapor deposition device 13, the sputtering device 14, and the etching device 15 as other processing devices may use general devices, and the description of the configuration thereof will be omitted.

[0037] Next, a method of manufacturing an organic EL device performed in the substrate processing system 1 configured as described above will be described.

[0038] Such as figure 2 As shown in (a), the positive electrode (anode) layer 20 is formed in advance on the upper surface of the glass substrate G. The positive electrode layer 20 includes, for example, a transparent conductive material such as indium tin oxide (ITO: Indium Tin Oxide). In addition, the positive electrode layer 20 is formed on the upper surface of the glass substrate G by, for example, a sputtering method or the like.

[0039] Then, in the cleaning device 12, after the surface of the positive electrode layer 20 on the glass substrate G is cleaned, as figure 2 As shown in (a), in the vapor deposition device 13, a light-emitting layer (organic layer) 21 is formed on the positive electrode layer 20 by a vapor deposition method. Furthermore, the light emitting layer 21 includes, for example, a multilayer structure in which a hole transport layer, a non-light emitting layer (electron block layer), a blue light emitting layer, a red light emitting layer, a green light emitting layer, and an electron transport layer are laminated.

[0040] Then, like figure 2 As shown in (b), in the sputtering device 14, a negative electrode (cathode) layer 22 including, for example, Ag, Al, or the like is formed on the light-emitting layer 21. The negative electrode layer 22 is formed, for example, by depositing target atoms on the light-emitting layer 21 through a pattern mask by sputtering. In addition, these positive electrode layer 20, light emitting layer 21, and negative electrode layer 22 constitute the organic EL element of this invention, and may be abbreviated as "organic EL element" hereafter.

[0041] Then, like figure 2 As shown in (c), in the etching device 15, the light-emitting layer 21 is dry-etched using the negative electrode layer 22 as a mask. In this way, the light-emitting layer 21 is patterned into a predetermined pattern.

[0042] In addition, after the etching of the light-emitting layer 21, the exposed part of the organic EL element and the glass substrate G (positive electrode layer 20) may be cleaned to remove substances adsorbed on the organic EL element, such as organic matter, that is, pre-cleaning . Furthermore, after pre-washing, for example, a silylation treatment using a coupling agent may be performed to form a very thin adhesion layer (not shown) on the negative electrode layer 22. The adhesion layer and the organic EL element are firmly bonded, and the adhesion layer and the silicon nitride film 23 described later are firmly bonded.

[0043] Then, like figure 2 As shown in (d), in the plasma film forming apparatus 16, for example, a silicon nitride film (SiN film) as a sealing film is formed so as to cover the peripheries of the light emitting layer 21, the negative electrode layer 22 and the exposed portion of the positive electrode layer 20 twenty three. The formation of the silicon nitride film 23 is performed by, for example, a microwave plasma CVD method as described later.

[0044] As described above, the manufactured organic EL device A can cause the light-emitting layer 21 to emit light by applying a voltage between the positive electrode layer 20 and the negative electrode layer 22. The organic EL device A can be applied to a display device and a surface light-emitting element (illumination, light source, etc.), and in addition, can be used in various electronic devices.

[0045] Next, the film forming method for forming the silicon nitride film 23 described above will be described together with the plasma film forming apparatus 16 for forming the silicon nitride film 23. image 3 It is a longitudinal cross-sectional view showing a schematic configuration of the plasma film forming apparatus 16. In addition, the plasma film forming apparatus 16 of the present embodiment is a CVD apparatus that generates plasma using a radial line slot antenna.

[0046] The plasma film forming apparatus 16 has, for example, a bottomed cylindrical processing container 30 with an open upper surface. The processing container 30 is formed of, for example, aluminum alloy. In addition, the processing container 30 is grounded. A mounting table 31 is provided in the approximate center of the bottom of the processing container 30 as a mounting portion for mounting, for example, a glass substrate G.

[0047] The mounting table 31 contains, for example, an electrode plate 32, and the electrode plate 32 is connected to a DC power supply 33 provided outside the processing container 30. The DC power supply 33 generates an electrostatic force on the surface of the mounting table 31, and the glass substrate G can be electrostatically attracted to the mounting table 31. In addition, the electrode plate 32 may be connected to, for example, a high-frequency power source (not shown) for bias.

[0048] A dielectric window 41 is provided in the upper opening of the processing container 30 via a seal 40 such as an O-ring for ensuring airtightness. The inside of the processing container 30 is closed by the dielectric window 41. A radial line slot antenna 42 is provided on the upper portion of the dielectric window 41 as a plasma excitation part for supplying microwaves for plasma generation. In addition, for the dielectric window 41, for example, alumina (Al 2 O 3 ). In this case, the dielectric window 41 reacts to nitrogen trifluoride (NF) used in dry cleaning. 3 ) Gas is resistant (corrosion resistance). In addition, in order to further improve the resistance to nitrogen trifluoride, the surface of the aluminum oxide of the dielectric window 41 may be covered with yttrium trioxide (Y 2 O 3 ), spinel (MgAl 2 O 4 ) Or aluminum nitride (AlN).

[0049] The radial line slot antenna 42 includes a substantially cylindrical antenna main body 50 with an open bottom surface. A disc-shaped slot plate 51 in which a plurality of slots are formed is provided in the opening on the lower surface of the antenna main body 50. A dielectric plate 52 made of a low-loss dielectric material is provided on the upper part of the slot plate 51 in the antenna main body 50. A coaxial waveguide 54 passing through the microwave oscillator 53 is connected to the upper surface of the antenna main body 50. The microwave oscillating device 53 is installed outside the processing container 30 and can oscillate microwaves of a predetermined frequency, for example, 2.45 GHz, to the radial line slot antenna 42. With this configuration, the microwave oscillated from the microwave oscillator 53 is transmitted to the radial line slot antenna 42, and after being compressed by the dielectric plate 52 to shorten the wavelength, a circularly polarized wave is generated in the slot plate 51, and the microwave is transmitted from the dielectric window 41 to the Radiation inside the container 30.

[0050] A raw material gas supply structure (structure) 60 having, for example, a substantially flat plate shape is provided between the mounting table 31 and the radial line slot antenna 42 in the processing container 30. The outer shape of the raw material gas supply structure 60 is formed in a circular shape that is at least larger than the diameter of the glass substrate G in a plan view. By this source gas supply structure 60, the processing container 30 is divided into a plasma generation region R1 on the side of the radial line slot antenna 42 and a source gas dissociation region R2 on the side of the mounting table 31. In addition, the raw material gas supply structure 60 may use alumina, for example. In this case, since alumina is ceramic, it has higher heat resistance and higher strength than metal materials such as aluminum. In addition, since the plasma generated in the plasma generation region R1 is not trapped, sufficient ions can be irradiated to the glass substrate. Furthermore, by irradiating the film on the glass substrate with sufficient ions, a dense film can be produced. In addition, the raw material gas supply structure 60 is resistant to nitrogen trifluoride gas used in dry cleaning. Furthermore, in order to improve the resistance to nitrogen trifluoride, the surface of the alumina of the raw material gas supply structure 60 may be covered with yttrium trioxide, spinel, or aluminum nitride.

[0051] Such as Figure 4 As shown, the source gas supply structure 60 is composed of continuous source gas supply pipes 61 arranged in a substantially lattice shape on the same plane. The raw material gas supply pipe 61 is formed to have a rectangular longitudinal section when viewed from the axial direction. A plurality of openings 62 are formed in the gap between the source gas supply pipes 61. The plasma and radicals generated in the plasma generation region R1 on the upper side of the source gas supply structure 60 can enter the source gas dissociation region R2 on the mounting table 31 side through the opening 62.

[0052] Such as image 3 As shown, a plurality of source gas supply ports 63 are formed on the lower surface of the source gas supply pipe 61 of the source gas supply structure 60. These raw material gas supply ports 63 are uniformly arranged in the surface of the raw material gas supply structure 60. The source gas supply pipe 61 is connected to a gas pipe 65 which communicates with a source gas supply source 64 provided outside the processing container 30. In the raw material gas supply source 64, for example, silane (SiH 4 ) Gas and hydrogen (H 2 ) Gas is used as raw material gas. The gas pipe 65 is provided with a valve 66 and a mass flow controller 67. With this configuration, silane gas and hydrogen gas at a predetermined flow rate are respectively introduced into the raw material gas supply pipe 61 from the raw material gas supply source 64 through the gas pipe 65. Then, these silane gas and hydrogen gas are supplied from each source gas supply port 63 to the lower source gas dissociation region R2.

[0053] The inner peripheral surface of the processing container 30 covering the outer peripheral surface of the plasma generation region R1 is formed with a first plasma excitation gas supply port 70 for supplying a plasma excitation gas used as a source of plasma. The first plasma excitation gas supply port 70 is formed at a plurality of positions along the inner peripheral surface of the processing container 30, for example. The first plasma excitation gas supply port 70 is connected to the first plasma excitation gas supply pipe 72, which penetrates the side wall of the processing container 30, for example, and is installed in the processing container 30. The external first plasma excitation gas supply source 71 communicates with each other. A valve 73 and a mass flow controller 74 are provided in the first plasma excitation gas supply pipe 72. With this configuration, it is possible to supply the plasma excitation gas at a predetermined flow rate into the plasma generation region R1 in the processing container 30 from the side. In this embodiment, for example, argon (Ar) gas is enclosed in the first plasma excitation gas supply source 71 as the plasma excitation gas.

[0054] On the upper surface of the source gas supply structure 60, a substantially flat plate-shaped plasma excitation gas supply structure 80 having the same configuration as the source gas supply structure 60 is laminated and arranged. The gas supply structure 80 for plasma excitation is composed of Figure 5 The illustrated second plasma excitation gas supply pipe 81 is arranged in a grid pattern. In addition, the gas supply structure 80 for plasma excitation may use alumina, for example. In this case, as described above, since alumina is ceramic, it has higher heat resistance and higher strength than metal materials such as aluminum. In addition, since the plasma generated in the plasma generation region R1 is not trapped, sufficient ions can be irradiated to the glass substrate. Furthermore, by irradiating the film on the glass substrate with sufficient ions, a dense film can be produced. In addition, the plasma excitation gas supply structure 80 is resistant to nitrogen trifluoride used in dry cleaning. Furthermore, in order to improve the resistance to nitrogen trifluoride, the surface of the alumina of the plasma excitation gas supply structure 80 may be covered with yttrium trioxide or spinel.

[0055] Such as image 3 As described above, a plurality of second plasma excitation gas supply ports 82 are formed on the upper surface of the second plasma excitation gas supply pipe 81. The plurality of second plasma excitation gas supply ports 82 are uniformly arranged in the plane of the plasma excitation gas supply structure 80. Thereby, the plasma excitation gas can be supplied to the plasma generation region R1 from the lower side to the upper side. In addition, in this embodiment, the gas for plasma excitation is, for example, argon. In addition to argon, it is also possible to supply nitrogen (N) as a source gas from the plasma excitation gas supply structure 80 to the plasma generation region R1. 2 )gas.

[0056] An opening 83 is formed in the gap between the grid-shaped second plasma excitation gas supply pipes 81, and plasma and radicals generated in the plasma generation region R1 can be supplied to the structure 80 and raw materials through the plasma excitation gas The gas supply structure 60 enters the lower source gas dissociation region R2.

[0057] The second plasma excitation gas supply pipe 81 is connected to a gas pipe 85 that communicates with a second plasma excitation gas supply source 84 provided outside the processing container 30. In the second plasma excitation gas supply source 84, for example, argon gas as a plasma excitation gas and nitrogen gas as a source gas are respectively enclosed. The gas pipe 85 is provided with a valve 86 and a mass flow controller 87. With this configuration, it is possible to supply nitrogen and argon at a predetermined flow rate from the second plasma excitation gas supply port 82 to the plasma generation region R1.

[0058] In addition, the above-mentioned source gas and plasma excitation gas constitute the processing gas of the present invention. In addition, the source gas supply structure 60 and the plasma excitation gas supply structure 80 constitute the processing gas supply unit of the present invention.

[0059] On both sides of the bottom of the processing container 30 sandwiching the mounting table 31, exhaust ports 90 for exhausting the atmosphere in the processing container 30 are provided. The exhaust port 90 is connected to an exhaust pipe 92 which communicates with an exhaust device 91 such as a turbo molecular pump. The exhaust gas from the exhaust port 90 can maintain the inside of the processing container 30 at a predetermined pressure, for example, 20 Pa to 60 Pa described later.

[0060] The above plasma film forming apparatus 16 is provided with a control unit 100. The control unit 100 is, for example, a computer and has a program storage unit (not shown). A program for controlling the film formation process of the silicon nitride film 23 on the glass substrate G in the plasma film formation apparatus 16 is stored in the program storage unit. In addition, the program storage unit also contains controls for the supply of the above-mentioned source gas, the supply of the plasma excitation gas, the irradiation of microwaves, the operation of the drive system, etc., for executing the film formation process in the plasma film forming apparatus 16 program. In addition, the above-mentioned program is a program stored in a computer-readable storage medium such as a computer-readable hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, etc., or It is a program installed in the control unit 100 from this storage medium.

[0061] Next, a film formation method of the silicon nitride film 23 performed in the plasma film formation apparatus 16 configured as described above will be described.

[0062] First, for example, when the plasma film forming apparatus 16 is activated, the supply flow rate of the argon gas supplied from the first plasma excitation gas supply port 70 and the supply flow rate of the argon gas supplied from the second plasma excitation gas supply port 82, It is adjusted so that the concentration of the argon gas supplied into the plasma generation region R1 is uniform. In the adjustment of the supply flow rate, for example, the exhaust device 91 is operated to form the same air flow in the processing container 30 as in the actual film formation process, and the supply from each plasma excitation gas supply port 70, 82 is set to Argon gas is supplied at an appropriate flow rate. Then, with this supply flow rate setting, film formation was performed on the substrate for actual testing, and it was checked whether the film formation was uniformly performed on the surface of the substrate. When the concentration of the argon gas in the plasma generation region R1 is uniform, the film formation on the substrate surface is uniformly performed. Therefore, the result of the inspection is that when the film formation is not uniformly performed on the substrate surface, change the argon gas With the setting of the supply flow rate of, film formation was performed on the test substrate again. The above steps are repeated, and the supply flow rate from each plasma excitation gas supply port 70, 82 is set so that film formation is uniformly performed in the substrate surface and the concentration of argon gas in the plasma generation region R1 becomes uniform.

[0063] As described above, after the supply flow rates of the respective plasma excitation gas supply ports 70 and 82 are set, the film forming process of the glass substrate G in the plasma film forming apparatus 16 is started. First, the glass substrate G is carried into the processing container 30 and held on the mounting table 31 by suction. At this time, the temperature of the glass substrate G is maintained at 100°C or less, for example, 50°C to 100°C. Next, the exhaust device 91 starts to exhaust the inside of the processing container 30, the pressure in the processing container 30 is reduced to a predetermined pressure, for example, 20 Pa to 60 Pa, and this state is maintained. In addition, the temperature of the glass substrate G is not limited to 100° C. or less, as long as it is a temperature at which the organic EL device A is not damaged, and it is determined by the material of the organic EL device A and the like.

[0064] Here, as a result of intensive research by the inventors, it was found that when the pressure in the processing container 30 is lower than 20 Pa, there is a possibility that the silicon nitride film 23 cannot be properly formed on the glass substrate G. In addition, it can be seen that when the pressure in the processing container 30 exceeds 60 Pa, the reaction between gas molecules in the gas phase increases, and particles may be generated. Therefore, as described above, the pressure in the processing container 30 is maintained at 20 Pa to 60 Pa.

[0065] When the pressure in the processing container 30 is reduced, argon gas is supplied from the first plasma excitation gas supply port 70 on the side, and nitrogen gas is supplied from the second plasma excitation gas supply port 82 below to the plasma generation region R1 And argon. At this time, the concentration of the argon gas in the plasma generation region R1 is maintained uniform in the plasma generation region R1. In addition, nitrogen gas is supplied at a flow rate of, for example, 21 sccm. Microwaves of 2.5 kW to 3.0 kW are radiated from the radial line slot antenna 42 to the plasma generation region R1 directly below at a frequency of 2.45 GHz, for example. By the irradiation of the microwave, the argon gas is plasmaized in the plasma generation region R1, and the nitrogen gas is radicalized (or ionized). In addition, at this time, the microwave traveling below is absorbed by the generated plasma. As a result, high-density plasma is generated in the plasma generation region R1.

[0066] The plasma and radicals generated in the plasma generation region R1 pass through the plasma excitation gas supply structure 80 and the raw material gas supply structure 60 into the lower raw material gas dissociation region R2. The raw material gas dissociation region R2 is supplied with silane gas and hydrogen gas from the raw material gas supply ports 63 of the raw material gas supply structure 60. At this time, for example, silane gas is supplied at a flow rate of 18 sccm, and for example, hydrogen gas is supplied at a flow rate of 64 sccm. In addition, the supply flow rate of the hydrogen gas is set according to the film characteristics of the silicon nitride film 23 as described later. The silane gas and hydrogen gas are respectively dissociated by the plasma entering from above. Then, the silicon nitride film 23 is deposited on the glass substrate G using these radicals and the radicals of the nitrogen gas supplied from the plasma generation region R1.

[0067] Then, when the silicon nitride film 23 is formed to form the silicon nitride film 23 with a predetermined thickness on the glass substrate G, the irradiation of microwaves and the supply of processing gas are stopped. Then, the glass substrate G is carried out from the processing container 30, and a series of plasma film forming processes are completed.

[0068] Here, as a result of intensive research by the inventors, it has been found that when the silicon nitride film 23 is formed on the glass substrate G by the plasma film forming process described above, a process gas containing silane gas, nitrogen gas, and hydrogen gas is used. As a result, the controllability of the film characteristics of the silicon nitride film 23 is improved.

[0069] Image 6 This shows how the wet etching rate for the silicon nitride film 23 of hydrofluoric acid changes when the supply flow rate of hydrogen in the process gas is changed using the plasma film forming method of the above-mentioned embodiment. In addition, at this time, the supply flow rate of silane gas was 18 sccm, and the supply flow rate of nitrogen gas was 21 sccm. In addition, in the plasma film forming process, the temperature of the glass substrate G was 100°C.

[0070] Reference Image 6 It can be seen that by further adding hydrogen to the process gas containing silane gas and nitrogen, the wet etching rate of the silicon nitride film 23 is reduced. Therefore, by treating the hydrogen in the gas, the density of the silicon nitride film 23 is improved, and the film quality (chemical resistance and compactness) of the silicon nitride film 23 is improved. In addition, the step coverage of the silicon nitride film 23 is also improved. Furthermore, it can be seen that the refractive index of the silicon nitride film 23 is increased to 2.0±0.1, for example. Therefore, by controlling the supply flow rate of hydrogen gas, the wet etching rate of the silicon nitride film 23 can be controlled, and the film characteristics of the silicon nitride film 23 can be controlled.

[0071] Figure 7 This shows how the film stress of the silicon nitride film 23 changes when the supply flow rate of hydrogen in the process gas is changed using the plasma film formation method of the above-mentioned embodiment. In addition, at this time, the supply flow rate of silane gas was 18 sccm, and the supply flow rate of nitrogen gas was 21 sccm. In addition, in the plasma film forming process, the temperature of the glass substrate G was 100°C.

[0072] Reference Figure 7 It can be seen that by further adding hydrogen to the process gas containing silane gas and nitrogen, the film stress of the silicon nitride film 23 changes to the negative side (compression side). Therefore, by controlling the supply flow rate of hydrogen, the film stress of the silicon nitride film 23 can be controlled.

[0073] As described above, according to the present embodiment, the film characteristics of the silicon nitride film 23 can be changed by changing the flow rate of hydrogen in the processing gas. Therefore, the silicon nitride film 23 can be appropriately formed as a sealing film in the organic EL device A, and therefore the organic EL device A can be appropriately manufactured. In addition, when used for a sealing film, the absolute value of the stress of the sealing film is preferably small.

[0074] In addition, in the plasma film forming method of this embodiment, the microwave radiated from the radial line slot antenna 42 is used to generate plasma. Here, the inventors’ research and discussion results show that when the processing gas contains silane gas, nitrogen and hydrogen, for example, Figure 8 The power of the microwave shown has a roughly proportional relationship with the film stress of the silicon nitride film 23. Therefore, according to the present embodiment, even by controlling the power of the microwave, the film stress of the silicon nitride film 23 can be controlled. By optimizing the flow rate of hydrogen and optimizing the microwave power, it is possible to obtain a film precisely having desired film characteristics. Specifically, after determining the power of the microwave, the flow rate of hydrogen can be optimized.

[0075] However, in the prior art, when a silicon nitride film is formed on a glass substrate, the above-mentioned silane gas and ammonia gas (NH 3 ) The gas is processed with gas. However, in a low temperature environment where the temperature of the glass substrate is 100° C. or less, the ammonia gas supplied before the formation of the silicon nitride film corrodes the metal electrode, such as the aluminum electrode, formed on the silicon nitride film base. In addition, since the film is formed in a low temperature environment, unreacted ammonia in the silicon nitride film is trapped. When ammonia is trapped in the silicon nitride film, after an environmental test or the like is performed, the ammonia is degassed from the silicon nitride film, which may deteriorate the organic EL device.

[0076] In this regard, in this embodiment, nitrogen is used instead of ammonia. Therefore, it is possible to prevent the corrosion of the metal electrode of the base and the deterioration of the organic EL device.

[0077] Moreover, as in this embodiment, nitrogen is used instead of ammonia, and hydrogen is added to the processing gas, such as Picture 9 It is shown that the film characteristics of the formed silicon nitride film can be improved. That is, the film quality (density) of the silicon nitride film in the step portion can be improved. In addition, Picture 9 The upper part of the shows the appearance of the silicon nitride film when a process gas containing silane gas and ammonia gas is used, and the lower part shows the appearance of the silicon nitride film when a process gas containing silane gas, nitrogen, and hydrogen is used. In addition, Picture 9 The left column shows the state of the silicon nitride film after film formation, and the right column shows the state of the silicon nitride film after 120 seconds of wet etching with buffered hydrofluoric acid (BHF).

[0078] In the plasma film forming apparatus 16 of the above embodiment, silane gas and hydrogen are supplied from the source gas supply structure 60, and nitrogen and argon are supplied from the plasma excitation gas supply structure 80. However, hydrogen may be supplied from the plasma The excitation gas supply structure 80 is supplied. Alternatively, hydrogen gas may be supplied from both the source gas supply structure 60 and the plasma excitation gas supply structure 80. In any case, as described above, by controlling the supply flow rate of hydrogen gas, the film characteristics of the silicon nitride film 23 can be controlled.

[0079] Here, as a result of research and discussion by the inventors, it is found that the film quality of the silicon nitride film 23, especially in the case of a dense film with the highest (large) Si-N bonding density in the film, the silicon nitride film 23 The refractive index is about 2.0. In addition, from the viewpoint of the barrier properties (sealing properties) of the silicon nitride film 23, the refractive index is preferably 2.0±0.1.

[0080] Therefore, in order to make the above-mentioned refractive index 2.0±0.1, it is preferable that the ratio of the supply flow rate of nitrogen gas to the supply flow rate of silane gas in the plasma film forming apparatus 16 be 1 to 1.5. In contrast, in a general (conventional) plasma CVD apparatus, when a silicon nitride film is formed using silane gas and nitrogen gas, the ratio of the supply flow rate of nitrogen gas to the supply flow rate of silane gas is usually 10-50. In a general plasma CVD apparatus, a large amount of nitrogen is required as described above. Therefore, in order to increase the film formation speed and increase the flow rate of the silane gas, a nitrogen flow rate in balance with the above increase is required, which creates a limit in the exhaust system. Therefore, it becomes difficult to maintain the above-mentioned refractive index of 2.0±0.1 as the refractive index of the silicon nitride film under the condition that the film formation speed is high. Therefore, the plasma film forming apparatus 16 of this embodiment has a very excellent effect compared with a normal plasma CVD apparatus.

[0081] In addition, by controlling the ratio of the supply flow rate of nitrogen gas to the supply flow rate of silane gas, the film stress of the silicon nitride film 23 can be controlled within the range of the refractive index of 2.0±0.1. Specifically, the film stress can be made close to zero. Furthermore, the film stress can also be controlled by adjusting the power of microwaves from the radial line slot antenna 42 and the supply flow rate of hydrogen.

[0082] In addition, as described above, the supply flow rate of nitrogen gas in the plasma film forming apparatus 16 can be made smaller than that of a normal plasma CVD apparatus because the supplied nitrogen gas can be easily activated and the degree of dissociation can be improved. That is, when the nitrogen gas is supplied from the plasma excitation gas supply structure 80, it is located very close to the dielectric window 41 where plasma is generated, and thus it is in line with the second plasma excitation gas of the plasma excitation gas supply structure 80. The supply port 82 is easier to ionize than the nitrogen gas discharged into the plasma generation region R1 in the processing container 30 in a relatively high-pressure state to generate a large amount of active nitrogen radicals and the like. Furthermore, as described above, in order to increase the degree of dissociation of nitrogen gas, the plasma excitation gas supply structure 80 is arranged at a position within 30 mm from the radial line slot antenna 42 (strictly speaking, the dielectric window 41). When the inventors conducted an investigation, when the gas supply structure 80 for plasma excitation is arranged in such a position, the gas supply structure 80 for plasma excitation itself is arranged in the plasma generation region R1. Therefore, the dissociation degree of nitrogen can be increased.

[0083] In the plasma film forming apparatus 16 of the above embodiment, the supply of the source gas may be performed at the same time as the plasma is generated or before the plasma is generated. That is, first, silane gas and hydrogen (or only silane gas) are supplied from the raw material gas supply structure 60. At the same time or after the supply of the silane gas and hydrogen gas, argon gas and nitrogen gas (and hydrogen gas) are supplied from the plasma excitation gas supply structure 80, and microwaves are radiated from the radial line slot antenna 42. Then, plasma is generated in the plasma generation region R1.

[0084] Here, the negative electrode layer 22 containing a metal element is formed on the glass substrate G on which the silicon nitride film 23 is formed. For example, when the organic EL device A including the negative electrode layer 22 is exposed to plasma, the negative electrode layer 22 is peeled from the light emitting layer 21, and the organic EL element A may be damaged. In contrast, in the present embodiment, since plasma is generated simultaneously with or after the supply of silane gas and hydrogen gas, the formation of the silicon nitride film 23 is started simultaneously with the generation of the plasma. Therefore, the surface of the negative electrode layer 22 is protected, the organic EL device A is not exposed to plasma, and the organic EL device A can be appropriately manufactured.

[0085] In the above embodiment, the source gas supply port 63 is formed to face downward from the source gas supply structure 60, and the second plasma excitation gas supply port 82 is formed to face upward from the plasma excitation gas supply structure 80, but The source gas supply port 63 and the second plasma excitation gas supply port 82 may be formed in an oblique direction other than the horizontal direction or the vertical downward direction, and are more preferably formed in a direction obliquely 45 degrees from the horizontal direction.

[0086] In this case, such as Picture 10 As shown, the raw gas supply structure 60 is formed with a plurality of raw gas supply pipes 61 extending parallel to each other. The source gas supply pipes 61 are arranged at regular intervals in the source gas supply structure 60. On both sides of the raw gas supply pipe 61, such as Picture 11 As shown, a source gas supply port 63 for supplying source gas in the horizontal direction is formed. Raw material gas supply port 63 such as Picture 10 As shown, they are arranged on the raw gas supply pipe 61 at equal intervals. In addition, the adjacent raw material gas supply ports 63 are formed so as to face in directions opposite to the mutually horizontal directions. In addition, the gas supply structure 80 for plasma excitation may have the same structure as the raw material gas supply structure 60 mentioned above. In addition, the raw material gas supply pipe 61 of the raw material gas supply structure 60 and the second plasma excitation gas supply pipe 81 of the plasma excitation gas supply structure 80 are substantially grid-shaped, and the raw material gas supply structure is arranged. 60 and the plasma excitation gas are supplied to the structure 80.

[0087] The source gas supplied from the source gas supply port 63 is mainly deposited on the source gas supply port 63 as silicon nitride, and therefore the deposited silicon nitride is removed by dry cleaning during maintenance. In this case, when the source gas supply port 63 is formed facing downward, it is difficult for plasma to enter the source gas supply port 63. Therefore, the silicon nitride deposited on the source gas supply port 63 may not be able to be completely inside. Remove. In this regard, as in the present embodiment, when the source gas supply port 63 faces the horizontal direction, plasma generated during dry cleaning enters the inside of the source gas supply port 63. Therefore, silicon nitride can be completely removed to the inside of the source gas supply port 63. Therefore, after maintenance, the source gas can be appropriately supplied from the source gas supply port 63, and the silicon nitride film 23 can be formed more appropriately.

[0088] In addition, the raw material gas supply pipe 61 of the raw material gas supply structure 60 and the second plasma excitation gas supply pipe 81 of the plasma excitation gas supply structure 80 are substantially grid-shaped, and the raw material gas supply structure is arranged. 60 and the plasma excitation gas are supplied to the structure 80. Therefore, it is possible to easily manufacture the raw material gas supply structure 60 and the plasma excitation gas supply structure 80 compared to forming the respective raw material gas supply structure 60 and the plasma excitation gas supply structure 80 themselves into a substantially lattice shape. In addition, plasma generated in the plasma generation region R1 can also easily pass.

[0089] In addition, such as Picture 12 As shown, the raw material gas supply port 63 may be formed so that its inner diameter expands in a conical shape from the inside to the outside. In this case, during dry cleaning, plasma is more likely to enter the inside of the source gas supply port 63. Therefore, the silicon nitride deposited on the source gas supply port 63 can be removed more reliably. In addition, the second gas supply port 82 for plasma excitation may also be formed such that its inner diameter expands in a conical shape from the inside to the outside.

[0090] In the above embodiment, the case where the silane gas is used as the silane gas has been described, but the silane gas is not limited to the silane gas. After the inventor’s research and discussion, it is known that, for example, the use of disilane (Si 2 H 6 In the case of a) gas, the step coverage of the silicon nitride film 23 is further improved compared to the case of using a silane gas.

[0091] In addition, in the plasma film forming apparatus 16 of the above embodiment, the microwave from the radial line slot antenna 42 generates plasma, but the generation of the plasma is not limited to this embodiment. As the plasma, for example, CCP (Capacitively Coupled Plasma), ICP (Inductively Coupled Plasma), ECRP (Electron Cyclotron Resonance Plasma), HWP (helicon wave plasma), etc. can also be used. In either case, the formation of the silicon nitride film 23 is performed in a low-temperature environment where the temperature of the glass substrate G is 100° C. or less, and therefore, it is preferable to use a high-density plasma.

[0092] Furthermore, in the above embodiment, the case where the silicon nitride film 23 is formed as a sealing film on the glass substrate G is described to manufacture the organic EL device A, but the present invention can also be applied to the case of manufacturing other organic electronic devices . For example, when manufacturing an organic transistor, an organic solar cell, an organic FET (Field Effect Transistor), etc. as an organic electronic device, the method for forming a silicon nitride film of the present invention can also be used. In addition to the production of such organic electronic devices, the present invention can also be widely used in the case of forming a silicon nitride film on a substrate under a low temperature environment where the temperature of the substrate is 100° C. or less.

[0093] As mentioned above, although the suitable embodiment of this invention was described with reference to drawings, this invention is not limited to this example. Those skilled in the art can of course think of various modifications and amendments within the scope of the ideas described in the scope of the patent claims, and those of course also belong to the technical scope of the present invention.

[0094] Symbol Description

[0095] 1 Substrate processing system

[0096] 16 Plasma film forming device

[0097] 20 positive layer

[0098] 21 luminescent layer

[0099] 22 negative layer

[0100] 23 Silicon nitride film

[0101] 30 disposal container

[0102] 31 Mounting table

[0103] 42 radial line slot antenna

[0104] 60 Raw material gas supply structure

[0105] 62 Opening

[0106] 63 Raw material gas supply port

[0107] 70 First gas supply port for plasma excitation

[0108] 80 Gas supply structure for plasma excitation

[0109] 82 2nd gas supply port for plasma excitation

[0110] 83 Opening

[0111] 90 exhaust port

[0112] 100 Control Department

[0113] A Organic EL device

[0114] G glass substrate

[0115] R1 Plasma generation area

[0116] R2 Raw material gas dissociation zone