JP2014027191A - Manufacturing method of photo-cvd film and manufacturing apparatus of photo-cvd film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus of a photo-CVD film capable of facilitating further improvement of uniformity of film thickness.SOLUTION: A manufacturing of a phot-CVD film includes (a) step of introducing material gas of the photo-CVD film to a reaction chamber that deposits the photo-CVD film and setting the reaction chamber at a predetermined pressure, (b) step of terminating the introduction of the material gas to the reaction chamber and emission of the material gas from the reaction chamber and radiating light to the reaction chamber, and (c) step of terminating the irradiation and emitting the material gas from the reaction chamber, and steps (a) to (C) are repeated multiple times.

Description

  The present invention relates to a photo-CVD film manufacturing method and a photo-CVD film manufacturing apparatus.

  Organic electroluminescence (hereinafter referred to as organic EL) elements have many advantages such as low power, self-emission, and high-speed response, and are being developed for application to flat panel displays (FPDs) and lighting equipment. . In addition, by using flexible substrates such as resin substrates (including resin films), new added values such as bending, lightness, and no cracking have been created, and application of organic EL elements to flexible devices is also being considered. Yes.

  Since organic EL devices come into contact with moisture and oxygen, the luminous efficiency decreases and the lifetime deteriorates. Therefore, it is necessary to exclude moisture and oxygen from the manufacturing process. On the other hand, in a flexible substrate such as a resin substrate, it is necessary to suppress dimensional variations associated with moisture absorption. For the above reasons, the organic EL element has barrier films formed on the front and back of the resin substrate. Here, the barrier film refers to a film that prevents moisture and oxygen from entering the organic EL element and the resin substrate from the outside, and a thin film having a high film density is used to suppress diffusion of moisture and oxygen. . As a specific material of the barrier film, a silicon nitride film (hereinafter, “Si nitride film”), an alumina film, or the like is used.

  The sealing film of the organic EL element, of course, prevents diffusion of moisture and oxygen, but (1) low temperature film formation (prevents organic EL deterioration), (2) low damage (prevents organic EL deterioration), (3) Low stress, low Young's modulus (preventing peeling), (4) high transmittance (preventing luminance deterioration), etc. are required. On the other hand, each material of the barrier film described above has a problem that film peeling or cracking occurs when a thick film is used because the film is hard (Young's modulus is large) and the film stress is large.

  Therefore, the multilayer thin film structure has been attracting the most attention as the structure of the sealing film of the organic EL element. This is a structure in which a plurality of thin films having different purposes are formed, and a structure in which a plurality of barrier films and a plurality of thin films (buffer films) that relieve the stress of the barrier film are stacked is known. Items required for the buffer film are excellent embedding performance in order to suppress the influence of foreign matter adhering to the surface and surface flatness, and the film must be soft (low Young's modulus) and low in film stress. It is. Specific examples of the buffer film include a silicon oxide film containing carbon.

  Patent Document 1 discloses a sealing film having such a laminated thin film structure. Various film-forming methods such as plasma CVD, photo-CVD, sputtering, and vapor deposition have been proposed as methods for manufacturing the sealing film, and typical examples include a barrier film and a buffer film formed continuously. The photo-CVD method using vacuum ultraviolet light is mentioned.

  There are Patent Documents 2 and 3 as apparatuses for producing a photo-CVD film. In the manufacturing apparatus of Patent Document 2, the source gas is introduced from the lateral direction of the sample (object to be processed). Moreover, in the manufacturing apparatus of Patent Document 3, the source gas is introduced from above the sample by dividing the transmission window above the sample into a plurality of parts and providing a plurality of gas inlets between the transmission windows.

JP 2005-63850 A JP-A-2005-340702 JP2012-12628A

  A general CVD apparatus includes a source gas introduction mechanism, a gas exhaust mechanism, and an automatic pressure control (APC) mechanism, and forms a photo-CVD film in the following steps. (1) A certain amount of source gas is introduced into the evacuated reaction chamber via a gas introduction valve. (2) Adjust the APC valve to set the pressure sensor to a predetermined pressure. (3) The vacuum ultraviolet lamp is turned on to start film formation by light irradiation. (4) When the predetermined time comes, the vacuum ultraviolet lamp is turned off and the reaction chamber is evacuated. Here, in the step (3), the exhaust amount is controlled so that the gas pressure in the reaction chamber becomes constant while introducing the raw material gas. Therefore, a gas flow, that is, a concentration distribution of the source gas exists in the reaction chamber. Since the deposition rate in the CVD method also depends on the gas concentration, it is necessary to make the gas concentration distribution uniform in order to improve the film thickness uniformity. In particular, in the photo-CVD method, since the source gas directly absorbs light and the decomposition and reaction proceed, the film formation rate tends to greatly depend on the gas flow and gas concentration.

  A specific example of such dependency is shown in FIG. FIG. 7 shows the film thickness uniformity when a photo-CVD film is formed on a sample having a diameter of 300 mm in a photo-CVD film manufacturing apparatus having a gas inlet port in the horizontal direction as in Patent Document 2. The film thickness uniformity is shown when only the gas pressure in the reaction chamber is changed while the supply amount of the source gas is constant. From FIG. 7, it can be seen that the film thickness uniformity varies greatly depending on the gas pressure. FIG. 8 shows the film thickness distribution (%) when the gas pressure is 60 Pa. The numerical value shows the distribution with respect to the average film thickness in the sample, and corresponds to the film thickness variation in which the interval between the individual contour lines is 2%. The arrows in the figure indicate the flow direction of the source gas on the sample. The film thickness tends to increase from the gas introduction side (lower left side in FIG. 8) toward the exhaust side (upper right side in FIG. 8). As described above, the film thickness of the photo-CVD film shows a feature that greatly depends on the flow of the source gas and the gas concentration.

  Even in such a film formation method, for example, a sample of a small size such as a 10 mm × 10 mm class, there is room for ensuring a certain degree of film thickness uniformity by optimizing the gas pressure and rotating the sample. . However, when the size of the sample becomes large like an 8th generation (2200 mm × 2500 mm) flat panel glass substrate, it is difficult to ensure film thickness uniformity only by optimizing the pressure. In addition, it is not realistic to form a film by rotating a large glass substrate.

  On the other hand, the photo-CVD film manufacturing apparatus of Patent Document 3 has a structure that can easily cope with a larger glass substrate. FIG. 9 shows the results of the study by the inventor of the present invention regarding the location dependence of the film thickness by the manufacturing apparatus described in Patent Document 3. FIG. 9 is a diagram showing the film thickness distribution with respect to the flow direction of the source gas. The source gas is assumed to be supplied from the upper part of G1 to G5 arranged at regular intervals. The source gas supplied to the processing chamber has a film forming rate that increases in the gas flow direction in which decomposition and reaction by light proceeds. However, when the gas is consumed, the film forming rate decreases. That is, the film thickness to be formed has a distribution like a sine wave in the gas flow direction with the gas introduction portion as a base point. In FIG. 9, the film thickness distribution by the gas inlets of odd numbers (G1, G3, G5) is indicated by a thin solid line, and the film thickness distribution by the gas inlets of even numbers (G2, G4) is indicated by a broken line. The film thickness obtained by adding the thin line and the broken line is the film thickness indicated by the thick solid line, which is the actual film thickness on the sample. In other words, if the film thickness distribution is a sinusoidal distribution with respect to the gas flow direction, a certain degree of film thickness uniformity can be achieved even on a large glass substrate by providing a gas inlet at the half-cycle position of the sine wave. Can be secured. Although FIG. 9 shows the gas introduction position only in the gas flow direction (X direction) (one-dimensional display), in reality, the gas introduction position is also required in the direction perpendicular to the gas flow (Y axis direction). Therefore, the gas introduction position is a two-dimensional arrangement with a constant interval.

  As described above, according to the photo CVD film manufacturing apparatus for introducing the source gas from above the sample as in Patent Document 3, the photo CVD film for introducing the source gas from the lateral direction as in Patent Document 2 is used. Compared with the manufacturing apparatus, it becomes possible to improve the uniformity of the film thickness. However, in the method shown in Patent Document 3, the arrangement of the gas inlets greatly affects the film thickness uniformity. That is, since it is necessary to introduce gas from between the transmission window and the transmission window, there are restrictions on the shape, size, and arrangement of the transmission window. In other words, the photo-CVD film deposition apparatus according to Patent Document 3 has a problem that can be studied only within a range in which the deposition conditions are matched with the gas introduction position.

  Therefore, even if the source gas is introduced from the lateral direction as in Patent Document 2, it is possible to improve the uniformity of the film thickness, and even if the source gas is introduced from above the sample as in Patent Document 3. In addition, a technology that relaxes restrictions on the arrangement of gas inlets is required. In light of the above, an object of the present invention is to provide a method or an apparatus for producing a photo-CVD film that makes it easier to improve film thickness uniformity.

  A representative example of means for solving the problems according to the present invention is a method for manufacturing a photo-CVD film, and (a) introducing a source gas of the photo-CVD film into a reaction chamber for forming the photo-CVD film. And (b) after step (a), the introduction of the source gas into the reaction chamber and the exhaust of the source gas from the reaction chamber are stopped, A step of irradiating light, and (c) after step (b), stopping the irradiation and then evacuating the reaction chamber, and repeating steps (a) to (c) a plurality of times. It is characterized by.

  Alternatively, a photo-CVD film manufacturing apparatus, a reaction chamber in which a substrate is installed, a light source unit that emits light from outside the reaction chamber, a transmission window that transmits light to the reaction chamber, and a photo-CVD film to the reaction chamber A first gas introduction valve that introduces the source gas, a first exhaust valve that is connected to the reaction chamber and exhausts the reaction chamber, and a second exhaust gas that is connected to the reaction chamber via the first exhaust valve and exhausts the reaction chamber. And an exhaust valve.

  Alternatively, a photo-CVD film manufacturing apparatus, a reaction chamber in which a substrate is installed, a light source unit that emits light from outside the reaction chamber, a transmission window that transmits light to the reaction chamber, and a photo-CVD film to the reaction chamber A first gas introduction valve for introducing the source gas, a plurality of first exhaust valves connected to the reaction chamber and exhausting the reaction chamber, and connected to the reaction chamber via a plurality of first exhaust valves, And a second exhaust valve having a larger diameter than the first exhaust valve.

  According to the present invention, it is possible to provide a manufacturing method or a manufacturing apparatus for a photo-CVD film that facilitates the improvement of film thickness uniformity.

1 is a view showing a photo-CVD film manufacturing apparatus according to Example 1. FIG. 6 is a diagram illustrating a method of manufacturing a photo-CVD film according to Example 1. FIG. It is a figure which shows the dependence of the film-forming speed | rate of a photo-CVD film with respect to the pressure of a reaction chamber. 6 is a view showing a photo-CVD film manufacturing apparatus according to Example 2. FIG. 6 is a view showing a photo-CVD film manufacturing apparatus according to Example 3. FIG. 6 is a view showing a method for producing a photo-CVD film according to Example 3. FIG. It is a figure explaining the subject regarding the film thickness uniformity of a photo-CVD film. It is a figure explaining the subject regarding the film thickness distribution of a photo-CVD film. It is a figure explaining the subject regarding the film thickness distribution of a photo-CVD film. 6 is a view showing a film thickness distribution of a photo-CVD film manufactured by the manufacturing method according to Example 1. FIG.

FIG. 1 is an outline of a photo-CVD film manufacturing apparatus according to the first embodiment. The apparatus includes a reaction chamber 501 for forming a photo CVD film, a sample susceptor 502, a sample 503, a transmission window 504, a vacuum ultraviolet light (VUV) lamp 505, and a source gas introduction valve for introducing a source gas of the photo CVD film. 506, reaction chamber pressure sensor 507, exhaust pipe 508 for exhausting source gas from the reaction chamber, exhaust valve 509, automatic pressure control (APC) valve (APC) 510, and vacuum pump 514 As in the optical CVD film manufacturing apparatus described in Patent Document 2, the source gas introduction valve 506 is lateral to the sample 503. However, the invention according to the present embodiment is characterized by the method of manufacturing the photo-CVD film, and the configuration of the photo-CVD film manufacturing apparatus is not limited to this. Similar to the one described in Patent Document 3, by combining the photo CVD film manufacturing apparatus provided with the source gas introduction valve in the upward direction with respect to the sample 503, and the photo CVD film forming method according to this embodiment, It is also possible to improve the uniformity of the film thickness. In this example, a film was formed using a Xe ₂ excimer lamp (wavelength = 172 nm) as the VUV lamp 505 and OMCTS (Octo methyl cyclotetrasiloxane) as an organic silicon source as the source gas. However, although OMCTS is mentioned as an example, these are one of the preferred examples, and the source gas is not limited to this source gas. Gases that have the same effect as OMCTS include TEOS (Tetra ethoxy silane) and oxygen, HMDSO (Hexa methyl disiloxane), and the like. Note that the walls of the reaction chamber 501 and the transmission window 504 were heated to 120 ° C. in order to suppress the adhesion of the reactants. On the other hand, the temperature of the sample susceptor 502 was controlled at 30 ° C. by a chiller.

  As described above, in the photo-CVD method, the film formation rate greatly depends on the flow of the source gas and the gas concentration. In other words, if there is no flow caused by the introduction or exhaust of the source gas in the reaction chamber and the gas concentration distribution is uniform, the film formation rate becomes uniform. In order to realize this, light may be irradiated in a state where gas is confined in the reaction chamber. For this purpose, by repeating the steps of bringing the pressure in the reaction chamber to a desired pressure, the step of irradiating light for a desired time with the flow of the source gas stopped, and the step of evacuating the photo-CVD film, A film forming method is effective.

  Based on the above, a method for producing a photo-CVD film according to Example 1 is shown in FIG. The method for producing a photo-CVD film according to FIG. 2 includes: (a) introducing a source gas of the photo-CVD film into a reaction chamber for forming the photo-CVD film to bring the reaction chamber to a predetermined pressure; and (b) a process. After (a), introducing the source gas into the reaction chamber, stopping the exhaust of the source gas from the reaction chamber, irradiating the reaction chamber with light, (c) irradiating after step (b) And then evacuating the reaction chamber, and the steps (a) to (c) are repeated a plurality of times.

  FIG. 10 shows the film thickness distribution of the photo-CVD film formed by the manufacturing method of this example. The gas pressure at the time of light irradiation was set to 60 Pa as in FIG. The uniformity of the film thickness of the photo-CVD film shown in FIG. 10 is dramatically improved as compared with FIG. As described above, by performing the method of manufacturing the photo-CVD film according to the present embodiment, it is possible to dramatically improve the film thickness uniformity of the photo-CVD film.

  Furthermore, when the photo-CVD film is formed by the manufacturing method according to this embodiment, not only the great advantage of improving the film thickness uniformity but also the restriction of the introduction position of the source gas, that is, the installation restriction of the transmission window can be relaxed. There are also advantages.

  More preferably, it is further characterized in that the predetermined pressure in step (a) is lower than the pressure at which the deposition rate of the photo-CVD film is maximized. In the photo-CVD method, there is a reaction chamber pressure at which the deposition rate is maximized for each gas type. FIG. 3 illustrates this state, in which the horizontal axis represents the pressure in the reaction chamber, and the vertical axis represents the deposition rate of the photo-CVD film. For example, about 70 Pa for gas type A and about 100 Pa for gas type B, although the specific reaction chamber pressure is different, the reaction chamber in which the deposition rate of the photo-CVD film is maximized for each gas type. There is a common point in the presence of pressure. This is because, in the film formation reaction of the photo-CVD film, the decomposition / reaction rate progresses as the source gas concentration increases, the component that increases the film formation rate, and the light that reaches the sample substrate increases as the light absorption in the source gas increases. This is because components that reduce the reaction rate and decrease in reaction rate coexist. Therefore, if the film formation is performed at a pressure equal to or higher than the maximum value, the use efficiency of the source gas is lowered. As a result, the raw material gas that has not been used for the film formation reaction remains in the reaction chamber, which causes the permeation window to become cloudy and lowers the reaction efficiency. Therefore, the pressure in the reaction chamber in the step (a) is preferably lower than the “pressure at which the film formation rate of the photo-CVD film is maximized”.

  As described above, in the first embodiment, the configuration of the manufacturing apparatus is not particularly limited. However, the manufacturing method of the photo-CVD film according to Example 1 involves a step (steps (a) and (c)) of opening and closing the exhaust-side valve many times at high speed, and therefore foreign matter is generated during opening and closing. It is also possible. Therefore, if the manufacturing apparatus has a foreign matter generation suppressing means, the uniformity of the film thickness can be further improved. In light of the above, Example 2 describes an apparatus for manufacturing a photo-CVD film that can further improve the uniformity of the film thickness.

  FIG. 4 shows an outline of a photo-CVD film manufacturing apparatus according to the second embodiment. FIG. 4 shows an optical CVD film manufacturing apparatus having two large exhaust pipes 108 and two APC (APC: Auto Pressure Control) valves 110 and 111. The apparatus configuration includes a reaction chamber 101, a sample susceptor 102, a sample 103, a transmission glass 104, a vacuum ultraviolet (VUV) lamp 105, a source gas introduction valve 106, a reaction chamber pressure sensor 107, an exhaust pipe 108, and an exhaust valve 109. The first APC valve 110, the second APC valve 111, the second APC valve pressure sensor 112, the nitrogen gas introduction valve 113, and the vacuum pump 114 are configured. The material of the transmission window 104 was synthetic quartz, which was divided into dimensions capable of maintaining mechanical strength. In this embodiment, the rectangular transmission window 104 has a short side = 200 mm and a long side = 1500 mm. FIG. 4 shows an example of a structure (short side direction) in which three transmission windows 104 are arranged, but the transmission windows 104 may be increased in accordance with the size of the sample to be used. For example, if ten transparent windows of this size are arranged, it is possible to cope with a glass substrate of the sixth generation size (1500 mm x 1850 mm). A reinforcing frame 115 that holds the transmission window 104 is installed between the transmission window 104 and the transmission window 104. The width of the reinforcing frame 115 is preferably as narrow as possible in order to make the light intensity distribution uniform while maintaining sufficient mechanical strength. In the present embodiment, in order to eliminate the influence of the light shielding portion of the reinforcing frame 115, the sample susceptor 102 is configured to operate in a two-dimensional direction. This operating width is preferably greater than or equal to the width of the reinforcing frame 115. In this embodiment, the left and right sides of the transmissive window 104 are moved at intervals of 50 mm in the short side direction. The direction in which the sample susceptor 102 is allowed to move and the width of the movement may be determined in consideration of the shape of the transmission window 104 and the width of the reinforcing frame 115.

  Here, a method of forming a photo CVD film by the manufacturing apparatus of FIG. 4 will be described. The feature of this structure is that the APC valve is composed of two stages in series. The first APC valve 110 at the front stage is linked with the reaction chamber pressure sensor 107, and the second APC valve 111 at the rear stage is linked with the pressure sensor 112 for the second APC valve. It is like that. The piping between the first APC valve 110 and the second APC valve 111 has a structure in which nitrogen gas whose flow rate is controlled is introduced via a gas valve 113.

  First, the gas introduction valve 106 is opened to introduce the source gas into the reaction chamber, and at the same time, a signal is output so that the reaction chamber pressure sensor 107 and the second APC valve pressure sensor 112 have the same pressure. At that time, the nitrogen gas valve 113 is opened to introduce a predetermined flow of nitrogen gas. Next, when the inside of the reaction chamber 101 reaches a predetermined pressure, the gas introduction valve 106 is closed and light irradiation is started. At this time, since the front and back of the first APC valve 110 are controlled to have the same pressure, the gas flow in the reaction chamber stops. After the film formation for a predetermined time, the nitrogen gas valve 113 is closed, the first APC valve 110 and the second APC valve 111 are fully opened, and the reaction chamber 101 is evacuated. By repeating this operation, a photo-CVD film is formed. Although the APC valve is shown in FIG. 4 as two stages connected in series, it is of course possible to increase the number of stages according to the purpose.

  As described above, the photo-CVD film manufacturing apparatus according to this example includes a reaction chamber (101) in which a substrate is installed, a light source unit (vacuum ultraviolet light lamp 105) that emits light from outside the reaction chamber, and the light. A permeation window (104) that allows the reaction chamber to permeate, a first gas introduction valve (106) that introduces a source gas of the photo-CVD film into the reaction chamber, and a first exhaust valve that is connected to the reaction chamber and exhausts the reaction chamber (110) and a second exhaust valve (111) connected to the reaction chamber via the first exhaust valve and exhausting the reaction chamber.

  Hereinafter, effects of the manufacturing apparatus will be described. As described above, when the exhaust valve is opened and closed, foreign matter is generated during opening and closing. In particular, in a large-scale manufacturing apparatus with a substrate size of the 8th generation class, a larger exhaust capacity is required, and it is necessary to reduce the conductance of the exhaust system. There are several ways to reduce the conductance of the exhaust system, but the most common method is to enlarge the exhaust pipe and the main valve of the exhaust system. However, if such a large exhaust valve is suddenly opened and closed many times, the amount of foreign matter generated is also increased.

  Therefore, it is desirable to employ a valve that further suppresses the generation of foreign matter. An example of such a valve is the APC valve described in this embodiment. Since the APC valve does not rapidly open and close like the diaphragm type valve, the generation of foreign matter can be almost eliminated even if the valve is enlarged. However, it is difficult to completely close the exhaust of the APC valve, and it is difficult to completely stop the exhaust gas in a normal configuration.

  On the other hand, according to the manufacturing apparatus according to the present embodiment, the gas flow in the reaction chamber can be substantially stopped by the combination of the first exhaust valve and the second exhaust valve. Therefore, it is possible to employ a valve (for example, an APC valve) that is less likely to generate foreign substances for the first and second exhaust valves, and to suppress the generation of foreign substances more than the manufacturing apparatus described in the first embodiment. It becomes possible to do. The important points in the manufacturing apparatus according to the present embodiment are that the film thickness uniformity of the photo-CVD film does not depend at all on the introduction position of the source gas, so that the degree of freedom of the installation location of the gas valve is increased, and the film thickness uniformity. Is a dramatic improvement. In addition, it is possible to stop the substantial gas flow in the reaction chamber by installing two or more APC valves in series, which are difficult to completely close the gas. For this reason, since the exhaust-side high-speed opening / closing operation can be performed only by the operation of the APC valve, it is possible to suppress the decrease in throughput and the generation of foreign matter even when a large apparatus is used.

  The apparatus for producing a photo-CVD film according to this embodiment further includes a second gas introduction valve (113) for introducing nitrogen gas into a region between the first exhaust valve and the second exhaust valve. . This is because the gas flow in the reaction chamber can be substantially stopped by making the region and the reaction chamber have the same pressure.

  The configuration for monitoring the pressure in the region and the reaction chamber further includes a first pressure sensor (107) for measuring the pressure in the reaction chamber and a second pressure sensor (112) for measuring the pressure in the region. Then, the second gas introduction valve may introduce nitrogen gas so that the measured value of the second pressure sensor becomes equal to the measured value of the first pressure sensor.

  Further, by configuring the second exhaust valve to be controlled by a signal from the first pressure sensor, the pressure in the reaction chamber can be more easily maintained at a pressure suitable for film formation.

  As described above, in the photo CVD film manufacturing apparatus according to this embodiment, the film thickness uniformity of the photo CVD film does not depend on the introduction position of the source gas. Therefore, the first gas introduction valve can be provided in the lateral direction of the substrate. According to such an arrangement, it is possible to further reduce the constraint conditions of the transmission window and the gas introduction port as compared with the optical CVD film manufacturing apparatus of Patent Document 3, and to improve the degree of freedom in apparatus design. .

  In the structure shown in FIG. 4, the source gas introduction valve 106 is shown in only two places, but a large number of gas introduction valves 106 may exist. Similarly, a large number of gas exhaust valves 109, APC valves 110 and 111, and pumps may exist. In this embodiment, an APC valve is used as an example of a valve that suppresses the generation of foreign matter from a diaphragm-type valve. However, other valves may be adopted as long as they have such an effect.

  In Example 3, an optical CVD film manufacturing apparatus that can further improve the uniformity of the film thickness, which is different from Example 2, will be described with reference to FIGS.

  FIG. 5 shows a photo-CVD film manufacturing apparatus according to this example. 5 includes a reaction chamber 201, a sample susceptor 202, a sample 203, a transmission glass 204, a VUV lamp 205, a source gas introduction valve 206, a reaction chamber pressure sensor 207, a plurality of exhaust pipes 208, a plurality of Exhaust valve 209, APC valve 210, and vacuum pump 214. Here, the feature of the manufacturing apparatus according to the present embodiment is that the reaction chamber 201 and the APC valve 210 (exhaust pipe 208) are connected via a plurality of small exhaust valves 209. This figure shows an example in which twelve exhaust valves 409 are connected in parallel. The twelve exhaust valves 409 are configured to open and close at the same time, but are not limited thereto. Similarly to the second embodiment, the material of the transmission window 204 is synthetic quartz, and shows a structure in which the mechanical strength is maintained and is divided and arranged. In order to eliminate the influence of the light shielding portion of the reinforcing frame 215, a sample is shown. The susceptor 202 is structured to operate in a two-dimensional direction.

Also in this example, film formation was performed using a Xe ₂ excimer lamp (wavelength = 172 nm) as the VUV lamp 205 and OMCTS of an organic silicon source as the source gas. The wall of the reaction chamber 201 and the transmission window 204 were set to 120 ° C., and the temperature of the sample susceptor 202 was set to 30 ° C. Here, the temperature of the wall of the reaction chamber 201 and the transmission window 204 is 120 ° C., but it is of course possible to further increase the temperature within a range where the heat resistance of the O-ring can be secured. As a method of heating the transmission window 204, there are a method of directly heating the transmission window 204 with a thin heater wire, a method of heating the reinforcing frame 215, and the like. In this embodiment, the reinforcing frame 215 is heated and the transmission window 204 is indirectly heated by the heat conduction.

  Hereinafter, a method for producing a photo-CVD film in this example will be described. The process flow during film formation follows the method shown in FIG. First, after the glass substrate 203 is transferred to the reaction chamber 201, the inside of the reaction chamber 201 is evacuated. Subsequently, all the exhaust valves on the exhaust side (12 are shown in the figure) are closed, and at the same time, the gas introduction valve 206 is opened to introduce OMCTS into the reaction chamber 201. When the pressure in the reaction chamber 201 starts to rise, the sample susceptor 202 is moved freely. When the pressure of the pressure sensor (P1) 207 in the reaction chamber reaches a predetermined pressure (for example, 70 Pa), the source gas introduction valve 206 is closed and the VUV lamp 205 is turned on. When a predetermined time elapses, the VUV lamp 205 is turned off and at the same time the exhaust valve 209 is fully opened and the reaction chamber 201 is evacuated. By repeating the above sequence, a photo-CVD film having a desired film thickness is formed.

  As described above, the photo-CVD film manufacturing apparatus according to this example includes a reaction chamber (201) in which a substrate is installed, a light source unit (vacuum ultraviolet lamp 205) that emits light from outside the reaction chamber, and the light. A transmission window (204) that allows the reaction chamber to pass through, a first gas introduction valve (206) that introduces a source gas of the photo-CVD film into the reaction chamber, and a plurality of first exhausts that are connected to the reaction chamber and exhaust the reaction chamber. It has a valve (209) and a second exhaust valve (210) connected to the reaction chamber via a plurality of first exhaust valves and having a diameter larger than that of the plurality of first exhaust valves.

  Due to this feature, the photo-CVD film manufacturing apparatus according to the present embodiment also has the same effects as the manufacturing apparatus according to the second embodiment. That is, since the film thickness uniformity of the formed photo-CVD film does not depend at all on the introduction position of the source gas, the degree of freedom in the installation location of the gas valve is increased, and the film thickness uniformity is dramatically improved. There are advantages such as.

  In addition, as compared with the second embodiment, by arranging a plurality of pipes and valves having a small diameter, it is possible to simultaneously realize small conductance and suppression of foreign matter generation. Further, since the exhaust valve is small, a high-speed opening / closing operation is possible, and in the film forming method of the present invention, the substantial film forming time ratio can be further increased. Here, the difference between the manufacturing apparatuses of Examples 2 and 3 will be described in comparison with FIG. 2 and FIG. The difference between FIG. 2 and FIG. 6 is the difference in the speed of stopping and starting the gas exhaust. FIG. 2 is a method of gently opening and closing the gas exhaust valve, while FIG. 6 is a method of making the opening and closing speed steep. As described above, the photo-CVD film manufacturing apparatus according to this embodiment employs a configuration in which the exhaust path is increased as a means for reducing the conductance of the exhaust system. Thus, the total conductance of the exhaust pipe can be reduced by reducing the diameter of one exhaust pipe and using a plurality of pipes. If the exhaust pipe is small, it is possible to use a small diaphragm valve. Therefore, the photo-CVD film manufacturing apparatus according to this embodiment can further suppress the generation of foreign matter even when performing a high-speed opening / closing operation. is there. Note that the reliability of a small diaphragm valve that performs multiple opening and closing processes has already been demonstrated by adopting it in an atomic CVD apparatus (ALD-CVD method). Therefore, as a combination of the exhaust valves, a diaphragm valve capable of suppressing the generation of foreign matters can be used as the plurality of first exhaust valves, and an APC valve can be used as the second exhaust valve.

  In this embodiment, the plurality of exhaust valves 209 are all opened / closed simultaneously, but the opening / closing timing of each valve may be shifted little by little so that the pressure does not fluctuate rapidly. In FIG. 5, two source gas introduction valves 206 are shown, but a plurality of source gas introduction valves 206 may actually exist. Similarly, a plurality of gas exhaust valves 209 may exist.

101, 201, 501: reaction chamber,
102, 202, 502: sample susceptor,
103, 203, 503: Sample (glass substrate),
104, 204, 504: transmission window (synthetic quartz),
105, 205, 505: VUV lamp,
106, 206, 506: Source gas introduction valve,
107, 207, 507: reaction chamber gas pressure sensor,
108, 208, 508: exhaust pipe,
109, 209, 509: exhaust valve,
110, 111, 210, 510: APC valve,
113: Nitrogen gas introduction valve,
114, 214, 514: vacuum pump,
115, 215: Reinforcing frame.

Claims (10)

(A) introducing a source gas of the photo-CVD film into a reaction chamber for forming the photo-CVD film, and setting the reaction chamber to a predetermined pressure;
(B) after the step (a), stopping the introduction of the source gas into the reaction chamber and the exhaust of the source gas from the reaction chamber, and irradiating the reaction chamber with light;
(C) after the step (b), stopping the irradiation, and then evacuating the reaction chamber,
The method for producing a photo-CVD film, wherein the steps (a) to (c) are repeated a plurality of times. In claim 1,
The method for producing a photo-CVD film, wherein the predetermined pressure in the step (a) is smaller than a pressure at which the film-forming speed of the photo-CVD film is maximized. An apparatus for manufacturing a photo-CVD film,
A reaction chamber in which the substrate is installed;
A light source unit that emits light from outside the reaction chamber;
A transmission window for transmitting the light to the reaction chamber;
A first gas introduction valve for introducing a source gas of the photo-CVD film into the reaction chamber;
A first exhaust valve connected to the reaction chamber and exhausting the reaction chamber;
An apparatus for producing a photo-CVD film, comprising: a second exhaust valve connected to the reaction chamber via the first exhaust valve and exhausting the reaction chamber. In claim 3,
The apparatus for producing a photo-CVD film, further comprising a second gas introduction valve for introducing nitrogen gas into a region between the first exhaust valve and the second exhaust valve. In claim 4,
A first pressure sensor for measuring the pressure in the reaction chamber;
A second pressure sensor for measuring the pressure in the region between the two,
The apparatus for producing a photo-CVD film, wherein the second gas introduction valve introduces the nitrogen gas so that a measured value of the second pressure sensor is equal to a measured value of the first pressure sensor. In claim 3,
A first pressure sensor for measuring the pressure in the reaction chamber;
The apparatus for producing a photo-CVD film, wherein the second exhaust valve is controlled by a signal from the first pressure sensor. In claim 3,
The apparatus for producing a photo-CVD film, wherein the first exhaust valve and the second exhaust valve are APC valves. In claim 3,
The apparatus for producing a photo-CVD film, wherein the first gas introduction valve is provided in a lateral direction of the substrate. An apparatus for manufacturing a photo-CVD film,
A reaction chamber in which the substrate is installed;
A light source unit that emits light from outside the reaction chamber;
A transmission window for transmitting the light to the reaction chamber;
A first gas introduction valve for introducing a source gas of the photo-CVD film into the reaction chamber;
A plurality of first exhaust valves connected to the reaction chamber and exhausting the reaction chamber;
An apparatus for producing a photo-CVD film, comprising: a second exhaust valve connected to the reaction chamber through the plurality of first exhaust valves and having a diameter larger than that of the plurality of first exhaust valves. In claim 9,
The plurality of first exhaust valves are diaphragm valves,
The apparatus for producing a photo-CVD film, wherein the second exhaust valve is an APC valve.