Film formation method

Abstract

To provide a film deposition method capable of possibly reducing a number of particles with a predetermined size or more attached to a substrate after a film deposition when depositing a transparent conductive oxide film with a target 21 of a sintered transparent conductive oxide.SOLUTION: A method further includes a step of introducing an exhaust gas from a same or another gas introduction port 61a into a vacuum chamber 1 after a power input to a target 21 is stopped according to a completion of a film deposition. An introduction amount of the exhaust gas is arranged in such a range that the exhaust gas introduced from the gas introduction port flows into an exhaust port 4 via a space 1a between the target and a substrate Sg.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a film forming method, and more particularly to a method for forming a transparent conductive oxide film on the surface of a film forming substrate by a sputtering method.

Background Art

[0002] For example, in the manufacturing process of a flat panel display device, there is a process of forming a transparent conductive film on the surface of a large-area glass substrate (hereinafter referred to as "substrate") as the film forming substrate. As the transparent electrode film, a transparent conductive oxide film including an indium oxide-based oxide film (for example, ITO film) is used. For the formation of such a transparent conductive oxide film, a magnetron sputtering apparatus is generally used in consideration of productivity and the like. Taking the case of forming an ITO film as an example, the substrate and the ITO target are arranged opposite to each other in the vacuum chamber of the sputtering apparatus, and a sputtering gas such as argon gas is introduced into the vacuum chamber evacuated to a predetermined pressure by a vacuum pump (in some cases, a reactive gas such as oxygen gas may be introduced as necessary), and a (pulsed) DC power or high-frequency power having a negative potential is applied to the ITO target. Then, a plasma atmosphere is formed in the vacuum chamber, and the ITO target is sputtered by the ions of the noble gas in the plasma atmosphere, and the sputtered particles scattered from the ITO target according to a predetermined cosine law adhere to and deposit on the substrate to be processed, and an ITO film is formed on the substrate surface (for example, see Patent Document 1).

[0003] In this process, when multiple substrates are loaded and unloaded into a vacuum chamber and an ITO target is sputtered to deposit a film onto each substrate sequentially, sputtered particles adhere to and accumulate on components such as anti-deposition plates present in the vacuum chamber. It has been known that these adhering particles can, for some reason, become fine particles (such as yellow powder) and scatter into the vacuum chamber. As a result, particles may adhere to the substrate surface after film deposition. In recent years, with the increasing resolution of flat panel displays, the quality of transparent conductive oxide films is sometimes judged by the number of particles of a predetermined size (e.g., 2 μm) or larger that adhere after film deposition, and particle adhesion is a factor that reduces product yield.

[0004] Therefore, the inventors diligently conducted research and came to the following conclusion: Among the fine particles scattered in the vacuum chamber, some remain suspended within the vacuum chamber without being evacuated (in cases where the target is a sintered body of a transparent conductive oxide, it is also conceivable that particles may scatter from its surface and become suspended when power to the target is stopped). During film deposition by sputtering of the target, particles suspended in the space between the target and the substrate become positively or negatively charged by the plasma, and these charged particles aggregate due to Coulomb force, increasing in size beyond a predetermined size depending on the plasma generation time (film deposition time). It is thought that these enlarged particles then adhere to the substrate surface immediately after film deposition following the cessation of power to the target. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-994 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention is based on the above findings and aims to provide a film deposition method that minimizes the number of particles of a predetermined size or larger adhering to the substrate after film deposition when a transparent conductive oxide film is deposited on the surface of the substrate by sputtering a sintered body of transparent conductive oxide as the target. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a film deposition method comprising the steps of: using a sintered body of a transparent conductive oxide as a target; arranging a substrate to be deposited on opposite sides in a vacuum chamber containing the target; introducing sputtering gas at a first flow rate from a gas inlet into the vacuum chamber, which is evacuated to a predetermined pressure by a vacuum pump through an exhaust port opened in the vacuum chamber; applying a predetermined power to the target to form a plasma atmosphere; and sputtering the target with ions of the sputtering gas in the plasma atmosphere to deposit a transparent conductive oxide film on the surface of the substrate; further comprising the steps of introducing exhaust gas into the vacuum chamber from the same or another gas inlet prior to or after stopping the power supply to the target; and setting the amount of exhaust gas introduced from the gas inlet to a range in which the exhaust gas introduced from the gas inlet flows through the space between the target and the substrate to be deposited and is transferred to the exhaust port.

[0008] Based on the above, it has been confirmed that the number of particles larger than a predetermined size adhering to the substrate after film formation can be reduced as much as possible. This is thought to be because, during film formation, particles floating in the space between the target and the substrate aggregate and increase in size beyond a predetermined size, and these increased particles become particles that adhere to the surface of the substrate immediately after film formation due to the cessation of power supply to the target. However, in the exhaust gas introduction process that follows the film formation process, when the exhaust gas is advected into the space, not only the particles still floating in the space but also the particles that have adhered to the substrate after film formation are stirred up and sent to the exhaust port along with the exhaust gas. Here, "advection" in this invention refers to the exhaust gas introduced from the gas inlet into a vacuum chamber at a predetermined pressure at a constant speed and flow rate, flowing uniformly from the gas inlet through the space to the exhaust port without generating vortices and diffusing inside the vacuum chamber, which is evacuated at a constant effective exhaust speed. For example, if the pressure in a vacuum chamber of a predetermined volume is set to a range of 0.1 Pa to 1 Pa, the amount of exhaust gas introduced will be set to a range of 10 sccm to 1000 sccm.

[0009] In the present invention, the sputtering gas introduced for forming the plasma atmosphere is used as the exhaust gas, and after stopping the power supply to the target, the introduction of the sputtering gas into the vacuum chamber is continued, and the exhaust gas can be advected by changing the amount of sputtering gas introduced to a second flow rate less than the first flow rate and increasing the effective pumping speed of the vacuum pump. On the other hand, the sputtering gas is used as the exhaust gas, and prior to stopping the power supply to the target, the exhaust gas can be advected by changing the amount of sputtering gas introduced to a second flow rate less than the first flow rate and increasing the effective pumping speed of the vacuum pump. This allows for, for example, a common introduction path for the sputtering gas and the exhaust gas, thereby reducing the number of parts and lowering costs. In this case, when loading and unloading multiple substrates to be coated into a vacuum chamber and sequentially depositing films onto each substrate by sputtering a target, for example, if exhaust gas is introduced at a constant rate (second flow rate) at all times (in other words, if exhaust gas is introduced continuously between the time a film is deposited on one substrate and the time a film is deposited on the next substrate), particles floating in the space can be constantly guided to the exhaust port, further reducing the number of particles that adhere to the substrates after film deposition. In addition, if the flow rate of the sputtering gas is changed prior to stopping power supply to the target, the start time of the flow rate change is set appropriately within a range that does not adversely affect film deposition (including the plasma state).

[0010] Furthermore, in this invention, it is preferable to blow the exhaust gas in a linear fashion from the gas inlet in order to efficiently lift up particles that have adhered to the substrate after film formation. Blowing the exhaust gas in a linear fashion in this way is advantageous because it allows particles floating in the space between the target and the substrate during film formation to be discharged from that space (i.e., the space where the plasma atmosphere is formed), thereby reducing the amount of particles that increase in size beyond a predetermined size due to aggregation. [Brief explanation of the drawing]

[0011] [Figure 1] A schematic cross-sectional view of a sputtering apparatus capable of carrying out the film deposition method of this embodiment. [Figure 2] A schematic cross-sectional view along line II-II in Figure 1. [Modes for carrying out the invention]

[0012] The embodiments of the film deposition method of the present invention will be described below with reference to the drawings, using as an example a case in which a glass substrate (hereinafter referred to as "substrate Sg") is used as the substrate to be deposited and an ITO target is used as the sintered target of a transparent conductive oxide, and an ITO film is deposited on one side of the substrate Sg in a vacuum chamber in a vacuum atmosphere by sputtering. In the following, terms indicating directions such as up, down, left, and right will be based on Figure 1, which shows the installation position of the sputtering apparatus.

[0013] Referring to Figure 1, the sputtering apparatus SM capable of carrying out the film deposition method of this embodiment includes a vacuum chamber 1, and a transport opening 11 for loading and unloading substrates Sg is formed in the side wall of the vacuum chamber 1. Although not specifically illustrated and described, a transport chamber, where a vacuum transport robot is positioned for loading and unloading substrates Sg into and out of the vacuum chamber 1 under a vacuum atmosphere, is connected to the side wall of the vacuum chamber 1 where the transport opening 11 is formed, via a gate valve. A sputtering cathode unit 2 is provided at the top of the vacuum chamber 1. The cathode unit 2 has an ITO target 21 with a contour corresponding to the substrate Sg. The ITO target 21 is bonded to a backing plate 22 and is attached to the upper opening of the vacuum chamber 1 via an insulator 23 with its sputtering surface 21a facing downwards. The output from a sputtering power supply 24 is also connected to the ITO target 2, and can be supplied with negative potential (pulsed) DC power or high-frequency power. Although not specifically illustrated, a magnet unit is positioned above the target 21 to apply a leakage magnetic field to the space 1a within the vacuum chamber 1 between the target 21 and the substrate Sg (i.e., the space where the plasma atmosphere is formed). Opposite the target 21, at the bottom of the vacuum chamber 1, a stage 3 on which the substrate Sg is placed is provided via an insulating material 31.

[0014] Referring to Figure 2, an exhaust port 4 is formed on the side wall of the vacuum chamber 1 (left side in Figure 1), and a vacuum pump 5 is connected to the exhaust port 4 via an exhaust pipe 51. Various types of vacuum pumps such as rotary pumps, cryopumps, and turbomolecular pumps are used in combination as the vacuum pump 5 to maintain a predetermined pressure (for example, 10°C) inside the vacuum chamber 1. -6The vacuum can be evacuated down to Pa. A conductance valve 52 is interposed in the exhaust pipe 51 to adjust the operating pumping speed of the vacuum pump 5. The contour and opening area of ​​the exhaust port 4 are not particularly limited, but if the substrate Sg is relatively large in area, it can be made into a shape that is elongated in the length direction of the substrate Sg (up and down direction in Figure 2) (rectangle in plan view). The height position of the exhaust port 4 from the bottom surface of the vacuum chamber 1 is set so that its upper edge is equal to or less than the height position of the substrate Sg placed on the stage 3.

[0015] Opposite the exhaust port 4, on the other side wall of the vacuum chamber 1 (right side in Figure 1), a gas introduction means 6 is provided to introduce argon gas (a rare gas) as the sputtering gas and reaction gases such as oxygen gas, which are introduced as needed, into the vacuum chamber 1 during film deposition on the substrate Sg by sputtering. The gas introduction means 6 includes a spray nozzle 61 positioned on the inside of the side wall of the vacuum chamber 1. The spray nozzle 61 is made of a metal cylinder longer than the length of the substrate Sg, and multiple nozzle holes 61a serving as gas inlets are arranged in a row on its outer surface at intervals in one direction, allowing sputtering gas to be blown out in a line from each nozzle hole 61a. The height position of the spray nozzle 61 from the bottom surface of the vacuum chamber 1 is set to be above the height position of the substrate Sg placed on the stage 3 (above the exhaust port 4).

[0016] Furthermore, a gas pipe 62 is connected to the spray nozzle 61, penetrating the side wall of the vacuum chamber 1 and protruding into its interior. Although not specifically illustrated and explained, a diffusion plate may be placed inside the spray nozzle 61 to diffuse the sputtering gas supplied through the gas pipe 62 so that inert gas is blown out approximately evenly from each nozzle hole 61a. The gas pipe 62 is connected to a gas source (argon gas or oxygen gas) not shown via a flow control valve 63 such as a mass flow controller. The spray nozzle 61 is also equipped with a motor 64 as a drive source to rotate it around its axis (rotation axis), and as will be described later, the spray angle may be changed between the film deposition process and the exhaust gas introduction process. A protective plate 12 is provided inside the vacuum chamber 1 so as to surround the space 1a. In this case, the protective plate 12 has openings 12a facing the exhaust port 4 and the spray nozzle 61, respectively. The film deposition method using the sputtering apparatus SM described above will now be explained in detail.

[0017] As shown in Figure 1, with the first substrate Sg placed on stage 3, the vacuum pump 5 evacuates the vacuum chamber 1 to a predetermined pressure. At this point, the flow control valve 63 of the gas introduction means 6 is controlled to introduce argon gas into the vacuum chamber 1 from the spray nozzle 61 at a predetermined first flow rate (e.g., 100 sccm). Simultaneously, the conductance valve 52 is controlled to reduce the effective pumping speed of the vacuum pump 5, thereby maintaining the vacuum chamber 1 at a predetermined pressure (e.g., 0.5 Pa). When a negative potential (pulsed) DC power is applied to the ITO target 21 by the sputtering power supply 24, a plasma atmosphere is formed in the space 1a within the vacuum chamber 1 between the target 21 and the substrate Sg, and the ITO target 21 is sputtered by ions of rare gas in the plasma atmosphere. This process is continued for a predetermined sputtering time, causing sputtered particles scattered from the ITO target 21 according to a predetermined cosine law to adhere to and accumulate on the upper surface of the substrate Sg, forming an ITO film with a predetermined thickness (film formation process).

[0018] When the pre-set sputtering time is reached, power to the ITO target 21 is stopped, while the introduction of argon gas through the spray nozzle 61 continues. In other words, the introduced argon gas is used as exhaust gas, and its flow rate is kept unchanged at the first flow rate (exhaust gas introduction process). At this time, the motor 64 may be rotated to rotate around its axis, changing the position of the spray nozzle 61 so that it faces diagonally downward. Simultaneously, the conductance valve 52 is controlled to increase the effective pumping speed of the vacuum pump 5, thereby maintaining the inside of the vacuum chamber 1 at a predetermined pressure (for example, 0.05 Pa). This allows the argon gas to be blown uniformly from one end to the other in the width direction of the substrate Sg surface. In this state, the deposited substrate Sg is unloaded through the transport opening 11 by a vacuum transport robot in a transport chamber (not shown), and subsequently, a second substrate Sg is loaded and placed on the stage 3.

[0019] When the second substrate Sg is placed on stage 3, the conductance valve 52 is controlled again while the introduction of argon gas (without changing the flow rate of the introduced argon gas) is continued, and the effective pumping speed of the vacuum pump 5 is reduced, thereby maintaining the inside of the vacuum chamber 1 at a predetermined pressure (for example, 0.5 Pa). Then, similarly to above, DC power is applied to the ITO target 21 to form a plasma atmosphere, and the ITO target 21 is sputtered by ions of rare gas in the plasma atmosphere, so that an ITO film of a predetermined thickness is deposited on the upper surface of the substrate Sg. By repeating the above, an ITO film is deposited on each of the multiple substrates Sg.

[0020] According to the above, the number of particles with a size equal to or larger than a predetermined size adhering to the surface of the substrate Sg after film formation can be made as small as possible. This is because, during film formation, even if particles of a predetermined size adhere to the surface of the substrate Sg immediately after film formation due to the stop of power supply to the target 21, when the exhaust gas is advected into the space 1a in the exhaust gas introduction step, not only the particles still floating in the space 1a but also the particles adhering to the substrate Sg after film formation are lifted up and sent to the exhaust port 4 together with the exhaust gas. For example, when the pressure in the sputtering apparatus SM is in the range of 0.1 Pa to 1 Pa, if the gas introduction amount of the exhaust gas is set in the range of 10 sccm to 1000 sccm, the exhaust gas introduced from the spray nozzle 61 can flow uniformly to the exhaust port 4 without generating vortices and diffusing inside the vacuum chamber 1.

[0021] Moreover, by configuring the gas introduction means 6 as described above, the introduction paths of the sputter gas and the exhaust gas can be shared, reducing the number of components and achieving cost reduction. In addition, by constantly introducing the exhaust gas at a constant introduction amount (second flow rate) even while the substrate Sg is being carried into and out of the vacuum chamber 1, the particles floating in the space 1a can always be guided to the exhaust port 4, and the number of particles adhering to the substrate Sg after film formation can be made even smaller. Furthermore, by blowing out the exhaust gas in a line shape from the spray nozzle 61, the particles floating in the space 1a during film formation can be surely discharged from the space 1a, and the amount of particles that increase to a size equal to or larger than a predetermined size due to aggregation can be reduced.

[0022] To confirm the effects of the present invention described above, the following experiment was conducted using the sputtering apparatus SM described above. As for the film deposition conditions, the target 21 was an ITO target 21, the power input from the sputtering power supply 24 was 6kW (2.5W / □), the sputtering gas and exhaust gas were argon gas, the gas introduction amount was 100 sccm, the pressure in the vacuum chamber 1 during film deposition was 0.3 Pa, and the film deposition time was 40 sec. Films were then deposited on multiple substrates Sg until a predetermined cumulative power was reached. After that, the substrates Sg before processing were transported through the transport opening 11 by a vacuum transport robot in a transport chamber (not shown) and temporarily placed on stage 3. After the vacuum chamber 1 was evacuated to a predetermined pressure, the substrates Sg were transported out through the transport opening 11 by the vacuum transport robot without introducing sputtering gas by the gas introduction means (and without sputtering the target 21) and transported to the load lock chamber (not shown). In this state, the number of particles larger than 0.5 μm attached to the surface of the substrate Sg was measured using a known particle counter, and the result was approximately 400.

[0023] Next, the substrate Sg before processing was further transported through the transport opening 11 by a vacuum transport robot and temporarily placed on stage 3. Then, after the vacuum chamber 1 was evacuated to a predetermined pressure, sputtering gas was introduced at 100 sccm by a gas introduction means. At this time, the conductance valve 52 of the exhaust pipe 51 was controlled to change the effective pumping speed of the vacuum pump 5 and maintain the vacuum chamber 1 at a predetermined pressure (for example, 0.05 Pa). After a predetermined time had elapsed, without sputtering the target 21, the substrate Sg was transported out through the transport opening 11 by the vacuum transport robot and placed in a load lock chamber (not shown). In this state, the number of particles 0.5 μm or larger adhering to the surface of the substrate Sg was measured in the same manner as above, and it was found to be approximately 250. In this case, mainly particles 0.5 μm or larger but smaller than 2 μm were reduced, confirming that the adhesion of particles floating in space 1a to the surface of the substrate Sg could be suppressed.

[0024] Next, the substrate Sg before processing was further carried in through the transfer opening 11 by a vacuum transfer robot in a transfer chamber (not shown) and placed on the stage 3. Then, the effective exhaust speed of the vacuum pump was decreased, and film formation was performed on the substrate Sg under the above-described film formation conditions. When a predetermined film formation time was reached, power supply to the target 21 and introduction of the sputtering gas by the gas introduction means 6 were stopped. Then, after the inside of the vacuum chamber 1 was evacuated to a predetermined pressure, the substrate Sg was carried out through the transfer opening 11 by the vacuum transfer robot and carried into a load lock chamber (not shown). When the number of particles of 0.5 μm or more adhering to the surface of the substrate Sg was measured in the same manner as above in this state, it was about 520. In this case, it was confirmed that particles of 1 μm or more and 2 μm or more were mainly increased, and particles of a predetermined size or more were increased due to aggregation during film formation.

[0025] Next, the substrate Sg before processing was further carried in through the transfer opening 11 by a vacuum transfer robot in a transfer chamber (not shown) and placed on the stage 3. Then, film formation was performed on the substrate Sg under the above-described film formation conditions. When a predetermined film formation time was reached, only power supply to the target 21 was stopped. At this time, while the introduction amount of the sputtering gas by the gas introduction means 6 was not changed, the conductance valve 52 was controlled to increase the effective exhaust speed of the vacuum pump 5, and the inside of the vacuum chamber 1 was maintained at a predetermined pressure (for example, 0.05 Pa). After the inside of the vacuum chamber 1 was evacuated to a predetermined pressure, the substrate Sg was carried out through the transfer opening 11 by the vacuum transfer robot and carried into a load lock chamber (not shown). When the number of particles of 0.5 μm or more adhering to the surface of the substrate Sg was measured in the same manner as above in this state, it was reduced to about 300. In this case, it was confirmed that particles of each size could be reduced at an equal ratio. Also, it was confirmed that it could be reduced to about 300 when the introduction of the sputtering gas by the gas introduction means 6 was continued without changing the introduction amount during the further carrying-in of the substrate Sg before processing through the transfer opening 11 by a vacuum transfer robot in a transfer chamber (not shown). From the above, it was confirmed that the number of particles of a predetermined size or more adhering to the surface of the substrate Sg after film formation can be made as small as possible by introducing the exhaust gas.

[0026] While embodiments of the present invention have been described above, various modifications are possible as long as they do not deviate from the technical concept of the present invention. In the above embodiments, the case in which the exhaust gas introduction system is the same as the sputtering gas introduction system was described as an example, but the invention is not limited to this, and the gases may be introduced separately and independently. Also, although argon gas was described as an example of exhaust gas, the invention is not limited to this, and inert gases other than argon gas, such as rare gases or nitrogen gas, can be used as long as they do not adversely affect the film formation in the vacuum chamber 1.

[0027] Furthermore, in the above embodiment, in order to advect the exhaust gas through space 1a to the exhaust port 4, the amount of sputtering gas introduced is always set to a first flow rate and the effective pumping speed of the vacuum pump 5 is changed as an example. However, the invention is not limited to this, and for example, the amount of sputtering gas introduced may be set to a second flow rate which is less than the first flow rate without changing the effective pumping speed of the vacuum pump 5, or the amount of sputtering gas introduced and the effective pumping speed may be changed. Moreover, in the above embodiment, the exhaust gas introduction process was described as being carried out after the power supply to the target 21 is stopped, but the invention is not limited to this, and the exhaust gas introduction process may be carried out prior to the power supply to the target 21 is stopped, that is, the exhaust gas may be advected by changing the amount of sputtering gas introduced to a second flow rate which is less than the first flow rate and increasing the effective pumping speed of the vacuum pump 5. In this case, the time at which the flow rate change starts is set appropriately within a range that does not adversely affect the film formation (including the plasma state).

[0028] In the above embodiment, the example described was one in which the number of particles of a predetermined size or larger adhering to the substrate Sg surface after film formation is reduced simply by introducing sputtering gas, but the invention is not limited to this. For example, a device that irradiates space 1a with microwaves may be incorporated into the vacuum chamber 1 to prevent aggregation by static elimination or to prevent static charge adhesion to the substrate Sg. Also, when stopping the power supply to the target 21, the power supply may be gradually reduced to suppress adhesion to the substrate Sg due to plasma disappearance. In this case, the exhaust gas introduction process may be carried out not only after completely stopping the power supply to the target 21, but also during or prior to the gradual reduction of the power supply. Furthermore, in the above embodiment, a so-called deposit-down type sputtering apparatus SM was described as an example, but the invention is not limited to this, and the present invention can also be applied to so-called side-deposit type and deposit-up type sputtering apparatuses. Furthermore, although the above embodiment described the case of depositing an ITO film as an example, the present invention can also be applied to the deposition of other transparent conductive oxide films such as IZO and ITIO films, which are deposited by sputtering using a metal (including alloy) target. [Explanation of symbols]

[0029] SM...Sputtering apparatus, Sg...Substrate (substrate to be coated), 1...Vacuum chamber, 1a...Space, 21...ITO target (target), 4...Exhaust port, 5...Vacuum pump, 6...Gas introduction means, 61...Spray nozzle (with gas inlet).

Claims

1. A film deposition method comprising a film deposition step in which a transparent conductive oxide film is deposited on the surface of the substrate, the target being a sintered body of a transparent conductive oxide, the substrate to be deposited on being placed opposite to the target in a vacuum chamber containing the target, the vacuum chamber being evacuated to a predetermined pressure by a vacuum pump through an exhaust port opened in the vacuum chamber, sputtering gas is introduced at a first flow rate from a gas inlet, a predetermined power is applied to the target to form a plasma atmosphere, and the target is sputtered with ions of the sputtering gas in the plasma atmosphere to deposit a transparent conductive oxide film, The process further includes, prior to or after stopping the power supply to the target, introducing exhaust gas from the same or another gas inlet into the vacuum chamber that has been evacuated by the vacuum pump, wherein the amount of exhaust gas introduced is set to a range in which the exhaust gas introduced from the gas inlet flows through the space between the target and the film-forming substrate to the exhaust port. A film formation method characterized by using the sputtering gas as the exhaust gas, continuing to introduce the sputtering gas into the vacuum chamber after stopping the power supply to the target, changing the amount of sputtering gas introduced to a second flow rate less than the first flow rate, and advecting the exhaust gas by adjusting the opening of a conductance valve interposed in the exhaust pipe connecting the exhaust port and the vacuum pump, at least one of the above.

2. A film deposition method comprising a film deposition step of which a transparent conductive oxide film is deposited on the surface of the substrate, wherein a sintered body of a transparent conductive oxide is used as a target, a substrate to be deposited is placed opposite to the target in a vacuum chamber provided with the target, a sputtering gas is introduced at a first flow rate from a gas inlet into the vacuum chamber which is evacuated to a predetermined pressure by a vacuum pump through an exhaust port opened in the vacuum chamber, a predetermined power is applied to the target to form a plasma atmosphere, and the target is sputtered with ions of the sputtering gas in the plasma atmosphere to deposit a transparent conductive oxide film, The process further includes, prior to or after stopping the power supply to the target, introducing exhaust gas from the same or another gas inlet into the vacuum chamber that has been evacuated by the vacuum pump, wherein the amount of exhaust gas introduced is set to a range in which the exhaust gas introduced from the gas inlet flows through the space between the target and the film-forming substrate to the exhaust port. A film formation method characterized by using the sputtering gas as the exhaust gas, and advecting the exhaust gas by changing the amount of sputtering gas introduced to a second flow rate less than a first flow rate prior to stopping the power supply to the target, and increasing the effective exhaust speed of the vacuum pump by adjusting the opening of a conductance valve interposed in the exhaust pipe connecting the exhaust port and the vacuum pump.

3. The film-forming method according to claim 1 or 2, characterized in that the gas inlets are formed in a plurality at intervals in one direction on the outer surface of a spray nozzle consisting of a cylindrical body, and the exhaust gas is blown out in a line from each gas inlet.

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