JP2018053272A - Film deposition apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of forming a film having excellent in-plane uniformity which is a membrane characteristic, by a plasma sputtering deposition process containing steam in gas.SOLUTION: In a film deposition apparatus provided with steam traps 173, 173 for removing steam through intake ports 174, 174 at least a part of which is opened on the furthermore outside than both ends of a substrate S corresponding to both ends of the substrate S held in a treatment chamber 10, even if steam adsorbed on side wall surfaces 101, 102 of the treatment chamber 10 is separated, the steam is captured by the steam trap 173, and therefor fluctuation of a steam concentration in a plasma space PL is suppressed, to thereby obtain a film having excellent in-plane uniformity.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for forming a film on a substrate surface using a plasma sputtering technique.

  There is a technique for forming a thin film of a metal oxide such as ITO (indium tin oxide) on the surface of a substrate by a plasma sputtering technique. In this technique, in order to improve the characteristics of a film to be formed, it has been proposed to include water vapor as a reactive gas in a sputtering gas during film formation. For example, Patent Document 1 describes that in the plasma sputtering film formation of ITO, the crystallinity of the film is controlled by adjusting the water vapor partial pressure in the gas. Patent Document 2 discloses that in plasma sputtering film formation of an oxide semiconductor, in order to suppress a decrease in the carrier concentration in the film while reducing the oxygen partial pressure in the gas that decreases the film formation rate, Is described.

JP 2012-172219 A WO2011 / 132418

  In recent years, there have been cases in which it is required to further increase the water vapor concentration in the gas for the purpose of further improving the film quality. For example, a process using water vapor instead of oxygen as a reactive gas has been studied. However, when the amount of water vapor added to the sputtering gas is increased to a certain extent, the in-plane uniformity of the film characteristics may be reduced. For example, in the case of an ITO film, it is known that the resistivity of the film varies greatly depending on the position unless the water vapor amount at the time of film formation is appropriate.

  This makes it difficult to increase the amount of water vapor during film formation, and a technique that can further improve the in-plane uniformity of film characteristics is desired.

  This invention is made in view of the said subject, In the film-forming apparatus which forms into a film | membrane surface using plasma sputtering technology, the in-plane uniformity of a film | membrane characteristic is favorable according to the film-forming process which contains water vapor | steam in gas. It is an object of the present invention to provide a technique capable of forming a simple film.

  One aspect of the present invention is a processing chamber having an internal space surrounded by a wall surface, a substrate holding means for holding the substrate in a state in which a film formation target region on the surface of the substrate is exposed in the processing chamber, When the length of the film formation target region in one reference direction parallel to the surface of the substrate is an effective length, a target whose length in the reference direction is longer than the effective length is set in the processing chamber. A target holding means for holding and facing the film formation target region; and plasma in the vicinity of a band-shaped region of the surface area of the target that faces the film formation target region and has a length in the reference direction longer than the effective length. Plasma generating means for generating; and gas supply means for supplying a gas containing water vapor to a plasma space in which the plasma is generated in the internal space of the processing chamber; A water vapor removing unit that removes water vapor from the atmosphere in the processing chamber outside the plasma space, and the water vapor removing unit is provided in a pair in the processing chamber with different positions in the reference direction. Water vapor is taken in from the intake port, and at each of the intake ports, at least a part of the opening is a film deposition apparatus outside the end of the film formation target region in the reference direction.

  According to the knowledge of the inventor of the present application, one of the causes of in-plane film characteristics non-uniformity in a film forming process including water vapor is a variation in water vapor concentration near the substrate surface on which film formation is performed. That is, the characteristics of the film are highly sensitive to the water vapor concentration at the time of film formation, and variations in the water vapor concentration with respect to the position cause in-plane non-uniformity of the film characteristics.

  Further, in the case where film formation is performed by plasma sputtering of a band-like region that extends long along one reference direction among the target surfaces arranged facing the substrate surface, the central part of the substrate surface that faces the central part of the band-like region Even if good film characteristics are obtained, the peripheral edge portion of the substrate corresponding to both end portions in the reference direction of the belt-like region may be inferior to the central portion. The present inventor has caused this phenomenon because water vapor present at a high concentration outside the plasma space, particularly near the wall of the processing chamber, enters the plasma space and raises the water vapor concentration near the end of the belt-like region. I found out.

  Therefore, in the present invention, the water vapor removing means takes in the water vapor from a pair of intake ports provided outside the both end portions in the reference direction in the film formation target region on the substrate surface, so that the water vapor is removed from the atmosphere outside the plasma space. It is the structure which removes. According to such a configuration, it is possible to reduce the water vapor concentration between the both end portions of the film formation target region in the reference direction and the processing chamber wall surface. As a result, as described in detail later, it was possible to effectively suppress the deterioration of the in-plane uniformity of the film characteristics caused by excessive water vapor.

  As described above, according to the present invention, by removing excess water vapor present in the processing chamber, particularly in the vicinity of the wall of the processing chamber, the non-uniformity of the water vapor concentration in the plasma space is suppressed, and the surface of the film characteristics is reduced. It becomes possible to form a film with good internal uniformity.

It is a figure which shows one Embodiment of the film-forming apparatus concerning this invention. It is an enlarged view which shows the principal part of this film-forming apparatus. It is a figure which shows an internal structure when the inside of a vacuum chamber is seen to a X direction. It is a 1st figure which shows typically the change of the resistivity of the ITO film | membrane formed into a film. It is a 2nd figure which shows typically the change of the resistivity of the ITO film | membrane formed into a film. It is a flowchart which shows the film-forming process in this embodiment. It is a figure which shows the carrying-in path | route of a board | substrate. It is a figure which shows an example of the change of the water vapor partial pressure in the atmosphere in a film-forming process.

  FIG. 1 is a view showing an embodiment of a film forming apparatus according to the present invention. More specifically, FIG. 1 is a side view and a top view showing an internal structure of a film forming apparatus 1 according to an embodiment of the present invention. In order to uniformly indicate directions in the following description, XYZ orthogonal coordinate axes are set as shown in FIG. The XY plane represents a horizontal plane. Further, the Z axis represents the vertical axis, and more specifically, the (−Z) direction represents the vertical downward direction.

  FIG. 2 is an enlarged view showing a main part of the film forming apparatus. The main configuration of the film forming apparatus 1 shown in FIG. 2 is substantially the same as that described in Japanese Patent Laid-Open No. 2015-189800 previously disclosed by the applicant of the present application. Therefore, the principle of operation of the apparatus and its operation will be mainly described in detail here with reference to the same publication for the operation principle of each part of the apparatus not mentioned in the present specification.

  The film forming apparatus 1 is an apparatus that forms a film on the surface of a substrate S to be processed by reactive sputtering. For example, the film forming apparatus 1 is applied for the purpose of forming a metal oxide film such as indium tin oxide (ITO) on one surface of a glass substrate as a substrate S, a resin flat plate, a sheet, a film, or the like. Is possible. Here, a case where film formation is performed on a rectangular or single-wafer type substrate S will be described as an example. However, the substrate S may have an arbitrary shape or a long sheet shape. Also good.

  The film forming apparatus 1 includes a vacuum chamber 10, a transport mechanism 3 and a sputter source 5 for transporting a substrate S disposed therein, and a control unit 19 that performs overall control of the film forming apparatus 1. The vacuum chamber 10 is a hollow box-shaped member having a substantially rectangular parallelepiped outer shape, and is arranged so that the upper surface of the bottom plate is in a horizontal posture. The vacuum chamber 10 is composed mainly of a metal such as stainless steel or aluminum, but a transparent window made of, for example, quartz glass may be partially provided in order to make the inside of the chamber visible.

  The transport mechanism 3 includes a carrier 31 that holds the substrate S with its lower surface open, a plurality of transport rollers 32 that contact the lower surface of the carrier 31 and support the carrier 31, and a carrier roller 32 by rotating the transport roller 32. And a transport driving unit (not shown) for moving the head 31 in the X direction. The transport driving unit is controlled by the control unit 19.

  The carrier 31 has a structure in which an opening 311 that is slightly smaller than the outer shape of the substrate S is provided on a flat plate. The lower surface of the substrate S faces the opening 311 and comes into contact with the peripheral edge of the lower surface of the base material S. S is held in a state where most of the central portion of the lower surface is exposed. The exposed area at the center of the lower surface of the substrate S becomes a “deposition target area” for film formation by plasma sputtering described later. The carrier may have a structure in which the upper surface of the substrate S is held by suction so that the entire lower surface of the substrate S is exposed. In this case, the entire lower surface of the substrate S can be the film formation target region.

  The transport mechanism 3 configured as described above transports the substrate S in the vacuum chamber 10 while maintaining the horizontal posture, and moves the substrate S in the X direction. The movement of the substrate S by the transport mechanism 3 may be a reciprocating movement as indicated by a dotted arrow in FIG. 1, or may be either the (+ X) direction or the (−X) direction.

  Gates 160 and 161 are provided at both ends of the vacuum chamber 10 in the X direction. When the gate 160 or the gate 161 is opened as necessary, the substrate S can be carried into the film forming apparatus 1 and the substrate S can be carried out from the film forming apparatus 1. If the film forming apparatus 1 is connected to another vacuum chamber via the gates 160 and 161, the substrate S can be loaded and unloaded while the vacuum state in the vacuum chamber 10 is maintained.

  A sputtering source 5 is provided below the substrate S that is transported in the vacuum chamber 10 by the transport mechanism 3. As shown in detail in FIG. 2, the sputter source 5 holds rotating cathodes 51 and 52, magnet units 53 and 54 provided inside the rotating cathodes 51 and 52, and rotating cathodes 51 and 52, respectively. Rotating drive units 55 and 56 that rotate while rotating, and an inductively coupled antenna 57 for generating a high-frequency electric field in the vacuum chamber 10 are provided.

  The rotating cathode 51 and the magnet unit 53 constitute a magnetron rotating cathode as a unit. Similarly, the rotating cathode 52 and the magnet unit 54 constitute a magnetron rotating cathode as a unit. Thus, this embodiment has a pair of magnetron-type rotating cathodes arranged at different positions in the X direction. The pair of magnetron-type rotating cathodes have symmetrical shapes with respect to the YZ plane, but the basic structure is the same.

  The rotary cathode 51 (52) includes a cylindrical base member 511 (521) whose axial direction and longitudinal direction are the Y direction orthogonal to the plane of FIG. 2, and a target material 512 (which covers the outer periphery of the base member 511 (512)). 522). The base member 511 (512) is a conductor, and is supported rotatably around the central axis by bearings (not shown) provided in the rotation drive unit 55 (56) corresponding to both ends in the Y direction. Yes. The rotation drive unit 55 (56) is controlled by the control unit 19.

  The target material 512 (522) includes all or a part of the material of the film formed on the substrate S. In an aspect in which a part of the film material is supplied as a reactive gas, the component is applied to the target material. It need not be included. When the film to be formed is an ITO film, for example, a mixed sintered body of tin oxide and indium oxide can be used as a target material. When the target material is conductive, the base member can be omitted. That is, the base member may be omitted by using a target material that is previously formed into a cylindrical shape. In this case, the rotation drive unit 55 (56) is configured to rotate while directly supporting the target material.

  During the process of generating plasma in the processing space PS, the target material 512 (522) rotates, so that the surface of the target material 512 (522) exposed to the processing space PS is constantly moved. Thereby, since it is avoided that only a specific position on the surface of the target material 512 (522) is sputtered and consumed, the utilization efficiency of the target material can be increased. In addition, since electric field concentration caused by local deformation of the target is suppressed, resistance to abnormal discharge such as arcing can be increased.

  A magnet unit 53 (54) disposed inside the rotary cathode 51 (52) includes a yoke 531 (541) formed of a magnetic material such as magnetically permeable steel, and a plurality of pieces provided on the yoke 531 (541). A magnet, that is, a central magnet 532 (542) and a peripheral magnet 533 (543) provided to surround the magnet are provided. The yoke 531 is a flat plate member extending in the Y direction, and is disposed to face the inner peripheral surface of the rotating cathode 51.

  A central magnet 532 extending in the Y direction is disposed on the center line along the longitudinal direction (Y direction) on the upper surface of the yoke 531. Further, an annular (endless) peripheral magnet 533 surrounding the periphery of the central magnet 532 is provided on the outer edge portion of the upper surface of the yoke 531. The central magnet 532 and the peripheral magnet 533 are, for example, permanent magnets. The polarities of the central magnet 532 and the peripheral magnet 533 on the side facing the inner peripheral surface of the rotating cathode 51 are different from each other.

  One end of a fixing member 534 (544) is fixed to the lower surface of the yoke 531 (541), and the other end of the fixing member 534 (544) is a rod-like shape extending in the Y direction at the center of the rotating cathode 51 (52). The support member 535 (545) is attached. The support member 535 (545) is not rotated by the rotation of the rotary cathode 51 (52), and therefore the position of the fixing member 534 (544) is also fixed. The fixing member 534 provided on the rotary cathode 51 is disposed upward from the support member 535, but inclined to the other rotary cathode 52 side. On the other hand, the fixing member 544 provided on the rotary cathode 52 is disposed to be inclined upward toward the other rotary cathode 51 from the support member 545. Accordingly, a static magnetic field is intensively formed in the processing space PS by the magnet units 53 and 54.

  An inductive coupling antenna 57 is provided on the bottom surface of the vacuum chamber 10 so as to protrude toward the space between the pair of rotating cathodes 51 and 52. The inductive coupling antenna 57 is also referred to as LIA (Low Inductance Antenna: a registered trademark of EM Co., Ltd.), and the surface of the conductor 571 formed in a substantially U shape is a dielectric 572 such as quartz. It has a structure coated with. The inductively coupled antenna 57 extends in the Y direction through the bottom surface of the vacuum chamber 10 with the U-shape turned upside down. A plurality of inductively coupled antennas 57 are arranged side by side in different positions in the Y direction. With the structure in which the surface of the conductor 571 is covered with the dielectric 572, the conductor 571 is prevented from being exposed to plasma. Thereby, it is avoided that the constituent elements of the conductor 571 are mixed into the film on the substrate S.

  The inductively coupled antenna 57 configured as described above can be regarded as a loop antenna having the winding direction as the X direction and the number of windings being less than one. Therefore, the inductance is low. By arranging a plurality of such small antennas side by side in a direction perpendicular to the winding axis direction, it is possible to form an induction electric field for generating plasma, which will be described later, in a wide range while suppressing an increase in inductance. is there.

  The film forming apparatus 1 also includes a chimney 11 that is a cylindrical or box-shaped shielding member that is disposed in the vacuum chamber 10 so as to surround the sputter source 5 and has an upper portion that is elongated in the Y direction. I have. The chimney 11 has a function as a shield that limits the scattering range of the plasma generated in the sputtering source 5 and the sputtered particles sputtered from the target.

  The upper surfaces of the rotary cathodes 51 and 52 and the lower surface of the substrate S held by the carrier 31 are opposed to each other through the opening 111 above the chimney 11. As will be described later, the space PS surrounded by these becomes a processing space for generating a plasma and sputtering the target to form a film on the substrate S.

  A reactive gas is introduced into the processing space PS from the reactive gas supply unit 6, and an inert gas as a sputtering gas is introduced from the sputtering gas supply unit 7. Specifically, the reactive gas supply unit 6 includes a reactive gas supply source 61 that supplies a reactive gas containing at least water vapor, a pipe 62 that guides the reactive gas to the processing space PS, and the chimney 11. A pair of nozzles 63, 63 that are provided and communicate with the reactive gas supply source 61 via a pipe 62, and a flow rate adjusting unit 64 provided in the middle of the pipe 62 are provided.

  The nozzles 63, 63 are disposed above the rotary cathodes 51, 52 and discharge reactive gas between the rotary cathodes 51, 52 facing each other in the processing space PS and the substrate S. The flow rate adjusting unit 64 has a function of controlling the flow rate of the reactive gas supplied to the processing space PS in accordance with a control command from the control unit 19. The flow rate adjusting unit 64 is preferably capable of automatically controlling the flow rate of the reactive gas, and may be provided with a mass flow controller, for example.

  On the other hand, the sputtering gas supply unit 7 discharges the sputtering gas into the vacuum chamber 10 and a sputtering gas supply source 71 that supplies an inert gas, for example, argon gas or xenon gas, introduced into the processing space PS as the sputtering gas. A pair of nozzles 73, 73, a pipe 72 connecting the sputtering gas supply source 71 and the nozzles 73, 73, and a flow rate adjusting unit 74 provided in the middle of the pipe 72 are provided.

  The pair of nozzles 73, 73 are provided on the bottom surface of the vacuum chamber 10 so as to sandwich the inductive coupling antenna 57, and discharge an inert gas as a sputtering gas into the processing space PS in the vacuum chamber 10. The flow rate adjusting unit 74 has a function of controlling the flow rate of the sputtering gas supplied to the processing space PS in accordance with a control command from the control unit 19. The flow rate adjusting unit 74 is preferably capable of automatically controlling the flow rate of the sputtering gas, and may be provided with, for example, a mass flow controller.

  An appropriate voltage is applied from the power supply unit 8 between the rotary cathodes 51 and 52 and the inductive coupling antenna 57. Specifically, a magnetron power supply 81 provided in the power supply unit 8 is connected to the base members 511 and 521 of the rotary cathodes 51 and 52, and an appropriate potential is applied from the magnetron power supply 81. On the other hand, a high frequency power supply 82 provided in the power supply unit 8 is connected to the inductive coupling antenna 57 via a matching circuit 83, and an appropriate high frequency voltage is applied from the high frequency power supply 82. The voltage value and the waveform output from each of the magnetron power supply 81 and the high frequency power supply 82 are controlled by the control unit 19.

  By applying an appropriate potential from the magnetron power supply 81 to the rotary cathodes 51 and 52, an electric field is formed on the surfaces of the rotary cathodes 51 and 52, more specifically near the surfaces of the target materials 512 and 522 facing the processing space PS. Thereby, a plasma of sputtering gas (magnetron plasma) is generated. That is, the magnetron power supply 81 applies a voltage necessary for generating magnetron plasma in the processing space PS to the rotating cathodes 51 and 52 by the static magnetic field formed by the magnet units 53 and 54. The output voltage of the magnetron power supply 81 can be various, such as a DC voltage, an AC voltage, and a voltage having a waveform in which an AC voltage or a pulse voltage is superimposed on the DC voltage. Moreover, the structure by which the alternating voltage of an antiphase is applied to the two rotating cathodes 51 and 52 may be sufficient.

  Further, by supplying high frequency power (for example, high frequency power of 13.56 MHz) from the high frequency power supply 82 to the inductive coupling antenna 57, a high frequency induction electric field is generated between the inductive coupling antenna 57 and the rotating cathodes 51 and 52, Inductivity coupled plasma (ICP) of sputtering gas and reactive gas supplied to the processing space PS is generated. The plasma generated in this way is also attracted to the static magnetic field formed in the processing space PS. As a result, high-density plasma is generated in the plasma space PL near the surfaces of the rotary cathodes 51 and 52 in the processing space PS surrounded by the surfaces of the two rotary cathodes 51 and 52 and the lower surface of the substrate S.

  The rotary cathodes 51 and 52, the magnet units 53 and 54, and the inductive coupling antenna 57 all extend long along the Y direction perpendicular to the paper surface of FIG. Therefore, the plasma space PL is also a space region having a shape extending in the Y direction along the surfaces of the rotary cathodes 51 and 52.

  The surfaces of the target materials 512 and 522 are thus sputtered by the plasma generated in the plasma space PL, and fine target material particles adhere to the lower surface of the substrate S together with the reactive gas, thereby forming a film on the surface (lower surface) of the substrate S. Is done. Specifically, film formation by plasma sputtering is performed on a band-shaped region along the Y direction among the film formation target regions on the lower surface of the substrate S, and the substrate S is parallel to the main surface and orthogonal to the Y direction. In other words, film formation is performed two-dimensionally over the entire film formation target region by scanning and moving in the X direction.

  At this time, the characteristics of the film are improved by adding water vapor to the reactive gas. Specifically, the resistivity of the ITO film is reduced, and the electrical characteristics as a conductive film are improved. This is thought to be due to the effect of modifying the film surface by H, O, OH radicals and the like generated by the plasma conversion of water vapor.

  Further, it has been found that a metal oxide film formed by plasma sputtering to which water vapor is added has good etching properties against weak acids. By improving the weak acid etching property, a film suitable for forming a fine pattern can be obtained. This is because the improvement in etching property makes it difficult for residues to occur during the etching process, and it is possible to suppress the residues from entering the gaps in the fine pattern and causing defects. Also from this point, the plasma sputtering method added with water vapor is useful.

  A vacuum pump 171 and a water vapor trap 173 are provided on the bottom surface of the vacuum chamber 10 as atmosphere control means 170 for controlling the inside of the processing space PS to an atmosphere suitable for plasma sputtering as described above. More specifically, an opening 172 is provided near the sputter source 5 and near the center in the Y direction on the bottom surface of the vacuum chamber 10, and a vacuum pump 171 is connected to the opening 172. The vacuum pump 171 evacuates the atmosphere in the vacuum chamber 10 and places the vacuum chamber 10 in a high vacuum state. When plasma is generated in the plasma space PL and film formation on the substrate S is performed, the atmospheric pressure in the vacuum chamber 10 is controlled to a predetermined film formation pressure. For example, a turbo molecular pump can be used as the vacuum pump 171.

  Further, a pair of openings 174 and 174 are provided on the bottom surface of the vacuum chamber 10 so that the positions are different in the Y direction so as to sandwich the opening 172. A water vapor trap 173 that removes water vapor from the atmosphere in the vacuum chamber 10 is connected to each of the openings 174. As the water vapor trap 173, for example, a cryopump that adsorbs and removes gas molecules on the surface of a cooled low-temperature member (not shown) can be used.

  However, it is preferable that only water vapor in the atmosphere is selectively removed, and other gas components, for example, inert gases such as argon and xenon, which are sputtering gases, are not removed. For this purpose, the temperature of the low temperature member is set to 80K to 130K, more preferably 100K to 120K. With such a temperature setting, water vapor in the atmosphere can be removed at high speed, while inert gases such as argon and xenon, oxygen gas, nitrogen gas, and the like are hardly removed.

  In this way, the atmospheric pressure in the vacuum chamber 10 is centrally managed by the vacuum pump 171, and the water vapor trap 173 acts to remove only water vapor without affecting the atmospheric pressure in the vacuum chamber 10. Thereby, the atmospheric pressure and the gas composition in the vacuum chamber 10 can be controlled independently and stably.

  In order to realize the atmosphere control in the vacuum chamber 10, the film forming apparatus 1 includes a mechanism for detecting plasma emission in the processing space PS and a mechanism for detecting the atmospheric pressure in the processing space PS. Specifically, a probe 191 made of, for example, an optical fiber is disposed in the vicinity of the nozzle 63 that supplies nitrogen gas to the processing space PS, and a part of the plasma emission generated in the processing space PS enters the probe 191. The probe 191 is connected to the spectroscope 192, and the output signal of the spectroscope 192 is input to the control unit 19.

  The control unit 19 detects the plasma intensity in the processing space PS by the plasma emission method (PEM) based on the output signal of the spectroscope 192, controls the flow rate adjusting unit 64 as necessary, and is supplied to the processing space PS. Control the flow rate of the reactive gas.

  A mass spectrometer 195 can also be used to more accurately detect the amount of reactive gas in the atmosphere. That is, as shown in FIG. 1, by installing a mass spectrometer 195 in the vicinity of the opening 172 to which the vacuum pump 171 is connected, the composition ratio of the atmosphere in the vacuum chamber 10 can be detected. As the mass spectrometer 195, for example, a quadrupole mass spectrometer can be used. Based on the detection signal from the mass spectrometer 195, the control unit 19 can determine, for example, the partial pressure of water vapor in the atmosphere.

  In the vacuum chamber 10, a pressure sensor 193 that outputs a signal corresponding to the atmospheric pressure in the processing space PS to the control unit 19 is provided. The control unit 19 controls the vacuum pump 171 according to the signal, whereby the atmospheric pressure in the processing space PS during film formation, that is, the film formation pressure is controlled to a predetermined value.

  The control unit 19 includes a CPU for performing various arithmetic processes, a memory and storage for storing programs executed by the CPU and various data, an interface for exchanging information with external devices and users, and the like. For example, a general-purpose computer device can be used as the control unit 19.

  The film forming apparatus 1 configured as described above forms a high frequency induction electric field for generating plasma by arranging a plurality of inductively coupled antennas 57 that are small antennas having low inductance in the Y direction and supplying high frequency power thereto. To do. According to such a configuration, it is possible to generate a high-density plasma at a low potential and a low temperature. Moreover, uniform plasma generation having an arbitrary shape and size is possible by appropriately setting the antenna arrangement.

  Furthermore, by using together the rotary cathodes 51 and 52 that function as magnetron type rotary cathodes, it is possible to intensively generate a particularly high-density plasma in a limited region (plasma space PL) in the processing space PS. is there.

  FIG. 3 is a diagram showing an internal structure when the inside of the vacuum chamber is viewed in the X direction. More specifically, FIG. 3 shows the inside of the vacuum chamber 10 when the film forming apparatus 1 is cut in a cross section passing through the openings 172 and 174 and parallel to the YZ plane, from the (+ X) direction to the (−X) direction. It is sectional drawing when seen. As shown in FIG. 3, the length in the Y direction of the target material 522 provided on the rotary cathode 52 is Y in the film formation target region FR that is an exposed portion excluding the peripheral portion that contacts the carrier 31 on the lower surface of the substrate S. Longer than the direction length. In other words, if the Y-direction length of the film formation target region FR is the “effective length” of the substrate S, the Y-direction length of the target material 522 is longer than the effective length.

  In the Y direction, both end portions of the target material 522 extend outward from the positions of both end portions of the film formation target region FR of the substrate S indicated by the alternate long and short dash line. The magnet unit 54 provided in the cylinder of the target material 522 is also longer than the effective length of the substrate S, and both end portions extend outside the both end portions of the film formation target region FR. The same applies to the other target material 512 and the magnet unit 53 located behind the target material 522 in the figure.

  Accordingly, the plasma space PL formed in the vicinity of the surfaces of the target materials 512 and 522 also extends to the outside from both ends of the film formation target region FR of the substrate S. By doing so, the high-density plasma generated in the plasma space PL becomes uniform over the entire film formation target region FR in the Y direction. Thereby, it is expected that the quality of the film formed in the film formation target region FR by plasma sputtering becomes uniform in the Y direction.

  However, as described below, in the ITO film formed on the substrate S, the resistivity tends to increase at both ends of the substrate S in the Y direction. The arrangement of the vacuum pump 171 and the water vapor traps 173 and 173 shown in FIG. 3 has been devised as a means for solving this problem. Before explaining this structure, first, the inventors' knowledge about this problem will be explained.

  4 and 5 are diagrams schematically showing changes in resistivity of the ITO film to be formed. More specifically, FIG. 4 is a diagram schematically showing the measurement results of the resistivity (at the center in the Y direction) of the ITO film obtained by variously changing the partial pressure of water vapor in the atmosphere by the film forming apparatus 1. It is. FIG. 5 is a diagram schematically showing the position dependency of the resistivity of the ITO film in the Y direction.

As shown by a solid line in FIG. 4, when the film formation is performed at each stage with the water vapor partial pressure (H ₂ O partial pressure) in the processing space PS being varied in multiple stages, the resistivity of the obtained ITO film becomes the water vapor content. Varies with pressure. That is, the resistivity, which is one of the electrical characteristics of the ITO film, is sensitive to the water vapor partial pressure during film formation. For example, in order to obtain a sufficiently low resistivity indicated by a one-dot chain line, there is a preferable range for the water vapor partial pressure during film formation, and when the water vapor partial pressure is lower than this range, the resistivity is high in both cases It tends to rise. This also means that positional and temporal fluctuations in the water vapor partial pressure during film formation can cause non-uniform film characteristics.

  Further, the position dependency of the resistivity is ideally constant regardless of the position and has a small value as indicated by reference symbol A in FIG. However, if the amount of water vapor at the time of film formation is inappropriate, the resistivity becomes high as indicated by the symbol B. Further, even when the amount of water vapor is set appropriately, as indicated by reference numeral C, the resistivity increases as it approaches the end portion even though a low resistance is obtained at the central portion of the substrate S in the Y direction. May rise.

  This tendency is particularly remarkable in a general magnetron plasma sputtering film forming apparatus. The general film forming apparatus referred to here is one that does not have the inductively coupled antenna 57 and the water vapor trap 173 in the structure of the film forming apparatus 1 shown in FIG. In a magnetron plasma sputtering film forming apparatus without an inductively coupled antenna, the plasma density tends to be low at both ends in the Y direction of the plasma space PL, which is considered to cause an increase in resistivity at the ends. .

  By providing the inductively coupled antenna 57, which is a low inductance antenna (LIA) with the Y direction as the longitudinal direction, the uniformity of the plasma density in the plasma space PL is improved, so the resistivity at the end as described above The rise of is suppressed to some extent. However, the resistivity at the end may still increase under film forming conditions where the water vapor partial pressure is high.

  According to the knowledge of the inventor of the present application, such an increase in resistivity is considered to be caused by an increase in the water vapor concentration in the vicinity of the edge of the substrate S in the Y direction. As shown in FIG. 4, the resistivity of the ITO film is sensitive to the water vapor partial pressure, and the resistivity increases when the water vapor partial pressure at the time of film formation is out of the proper range. Even if the water vapor partial pressure is appropriate and a low resistance is obtained at the center of the substrate S, the resistivity increases at that portion if the water vapor partial pressure is high at the end.

  Here, considering a case where a part of the water vapor leaks from the plasma space PL, such water vapor may be adsorbed to each part in the vacuum chamber 10 in the form of water molecules. Such water molecules are liberated irregularly in the atmosphere. In particular, as shown in FIG. 3, in the vicinity of both ends of the substrate S located near the side wall surfaces 101 and 102 of the vacuum chamber 10, the water vapor concentration tends to increase due to water molecules released from the side wall surfaces 101 and 102. .

  In view of this, in the film forming apparatus 1 of the present embodiment, a water vapor trap 173 for removing water molecules floating outside the plasma space PL from the atmosphere is provided in the vacuum chamber 10. As shown in FIG. 3, in the bottom surface 103 of the vacuum chamber 10, the opening 174 to which the water vapor trap 173 is connected has at least a part of the opening at the end of the film formation target region FR of the substrate S in the Y direction. Has reached the outside. In other words, in the Y direction, openings 174 connected to the water vapor trap 173 are provided between both end portions of the film formation target region FR and the side wall surfaces 101 and 102 of the vacuum chamber 10.

  For this reason, the water vapor liberated from the side wall surfaces 101 and 102 and the bottom surface 103 of the vacuum chamber 10 is captured and removed by the water vapor trap 173 before reaching the vicinity of the end of the substrate S. Thereby, an increase in the water vapor concentration in the vicinity of the edge of the substrate is prevented, and an increase in resistivity due to this is suppressed. When a cryopump is used for the water vapor trap 173, the water vapor can be selectively removed by setting the temperature, and in addition, since it has a high exhaust speed in principle, it is released from the wall surface of the vacuum chamber 10. It is possible to effectively remove the water vapor.

  Actually, when film formation is performed by combining the magnetron plasma by the rotating cathodes 51 and 52, the inductively coupled plasma by the inductively coupled antenna 57, and the water vapor removal by the water vapor trap 173 in the film forming apparatus 1, reference numeral A in FIG. As shown, an ITO film having low resistance and little position dependency could be obtained. In addition, as shown by a broken line in FIG. 4, the effect that the range of the partial pressure of water vapor in which a low resistance is obtained is widened to the higher pressure side was also confirmed. Therefore, the film formation can be performed with the water vapor partial pressure higher than the conventional one. Further, since it can be said that the sensitivity of the resistivity to the water vapor partial pressure is low, it is possible to suppress changes in film characteristics due to fluctuations in the water vapor partial pressure during film formation.

  In the film forming apparatus 1, a gate valve 175 whose opening degree can be adjusted by a control command from the control unit 19 is provided between the opening 174 and the water vapor trap 173. Thereby, it is possible to adjust the strength of water vapor removal from the atmosphere. That is, in this film forming apparatus 1, it is possible to adjust the strength of water vapor removal by the water vapor trap 173 independently of the exhaust speed by the vacuum pump 171. Therefore, by adjusting the opening degree of the gate valve 175, it is possible to eliminate the uneven concentration of water vapor while maintaining the degree of vacuum defined by the vacuum pump 171.

  Since the cryopump has a high exhaust capacity in principle, it can be used for the purpose of keeping the pressure in the vacuum chamber 10 at the film forming pressure. However, since it is difficult to continuously absorb the sputtering gas or the like supplied into the vacuum chamber 10 for a long time, it is not suitable for continuous operation. Further, the water vapor removal capacity cannot be adjusted independently of the exhaust capacity. Therefore, it is preferable that the exhaust pump 171 for maintaining the atmospheric pressure in the vacuum chamber 10 and the water vapor trap 173 for the purpose of equalizing the water vapor partial pressure are separated.

  Since the opening 172 to which the exhaust pump 171 is connected is provided near the center in the Y direction of the bottom surface 103 of the vacuum chamber 10, there is a bias between the (−Y) side region and the (+ Y) side region in the vacuum chamber 10. It can exhaust without. In addition, by providing a pair of openings 174 and 174 to which the water vapor trap 173 is connected so as to sandwich the opening 172, the vicinity of the side wall surfaces 101 and 102 of the vacuum chamber 10 that cannot be exhausted by the exhaust pump 171. Water vapor unevenly distributed in the water can be effectively discharged.

  In the configuration in which the openings 174 and 174 are provided near the center of the bottom surface of the vacuum chamber 10, it is difficult to sufficiently suppress an increase in water vapor concentration in the vicinity of the side wall surfaces 101 and 102. In order to keep the water vapor concentration constant from the center to the end of the substrate S, it is desirable that at least a part of the openings 174 and 174 is located outside the end of the substrate S.

  Even in the case where only one set of the opening 174 and the water vapor trap 173 connected thereto is provided, it is difficult to suppress both the increase in the water vapor concentration at both ends of the substrate S. For this reason, it is preferable to provide a pair of water vapor traps 173 corresponding to both ends of the substrate S in the Y direction.

  In order to suppress adhesion of water vapor leaking from the processing space PS, heaters 121 and 122 may be provided on the side wall surfaces 101 and 102 of the vacuum chamber 10 as shown in FIG. The heaters 121 and 122 may be heat generating members such as a rubber heater whose temperature is adjusted by the control unit 19, or may be a piping network through which an appropriate heat transfer medium such as hot water flows. From the viewpoints of water vapor adhesion prevention effect, energy efficiency, member durability, and the like, the heating temperature of the side wall surfaces 101 and 102 is preferably 90 ° C. or lower.

  Next, a process for forming a film on the substrate S using the film forming apparatus 1 configured as described above will be described. Here, the case where film formation is performed on a single substrate S of a single-wafer type will be mainly described. However, as will be described later, when a plurality of substrates are processed continuously or for a long sheet-like substrate. It is possible to cope with continuous processing.

  FIG. 6 is a flowchart showing the film forming process in this embodiment. This process is realized by the control unit 19 executing a predetermined control program in response to an instruction input from the user and causing each unit of the device to perform a predetermined operation. First, the gate 160 or the gate 161 is opened, and the target material 512 (522) is attached to the base member 511 (521) of the rotary cathode 51 (52) (step S101). Alternatively, the base member 511 (521) on which the target material 512 (522) is mounted on the surface may be attached to the film forming apparatus 1 main body.

  When the gate is closed, evacuation of the vacuum chamber 10 is started by the vacuum pump 171 (step S102). The water vapor trap 173 is activated when a certain degree of vacuum is reached (step S103). Subsequently, the substrate S is carried into the vacuum chamber 10 via the gate 160 or the gate 161 (step S104).

  FIG. 7 is a diagram showing a substrate carry-in route. Here, it is assumed that the film is loaded into the film forming apparatus 1 through the gate 160. As shown in FIG. 7, the film forming apparatus 1 is connected to the load lock chamber 20 through a gate 160. A vacuum pump 201 is connected to the load lock chamber 20, and the internal space can be decompressed to a vacuum level similar to that of the vacuum chamber 10. In addition, the load lock chamber 20 is provided with a gate 202 that opens and closes to and from the external space. The substrate S is taken in and out between the external space and the internal space of the load lock chamber 20 via the gate 202. At this time, the internal space of the load lock chamber 20 is opened to the atmosphere.

  The substrate S carried into the load lock chamber 20 is set on a carrier 31 installed in the load lock chamber 20 in advance. Alternatively, the substrate S may be loaded into the load lock chamber 20 in a state where the substrate S is set on the carrier 31. Thereafter, the inside of the load lock chamber 20 is depressurized by the vacuum pump 201, and a vacuum state similar to that of the vacuum chamber 10 is obtained. Then, the gate 160 is opened and the carrier 31 is carried into the vacuum chamber 10. Therefore, even if the gate 160 is opened to carry the substrate S, the vacuum state of the vacuum chamber 10 is not broken.

  As described above, the water vapor adsorbed on the wall surface of the vacuum chamber 10 is liberated at the time of film formation, so that the characteristics of the film greatly fluctuate. It is desirable to avoid opening the vacuum chamber 10 to the atmosphere when the substrate S is carried in and out, because it allows new water vapor to enter the vacuum chamber 10. By causing the substrate S to be carried in and out through the evacuated load lock chamber 20, this problem can be solved.

  At this point, the carrier 31 that holds the substrate S is positioned at a position that is largely retracted from the position immediately above the sputtering source 5 as indicated by a solid line in FIG. It is preferable that the opening 172 to which the vacuum pump 171 is connected is retracted to the side opposite to the sputtering source 5.

  Returning to FIG. 6, next, the supply of the sputtering gas from the sputtering gas supply unit 7 to the vacuum chamber 10 and the voltage supply from the power supply unit 8 to each unit are started (step S105). Thereby, plasma by sputtering gas is generated in the processing space PS (plasma lighting), and sputtering of the target is started. At this time, the reactive gas containing water vapor is not introduced into the vacuum chamber 10.

  At this time, the foreign matter adhering to the target surface is beaten out by the sputtering gas plasma and discharged by the vacuum pump 171, thereby cleaning the target surface (pre-sputtering). Since the substrate S is in a position retracted from the sputter source 5, foreign matter released from the target surface does not adhere to the substrate S. Further, a member for adsorbing such foreign matter may be provided above the sputtering source 5.

  Subsequently, the supply of the reactive gas containing water vapor from the reactive gas supply unit 6 is started (step S106). At this time, a predetermined amount of water vapor is not supplied all at once, but the amount of water vapor introduced is increased little by little while confirming the detection result of plasma emission intensity or the result of mass spectrometry. When the detected water vapor amount reaches a predetermined value (step S107), the increase in the water vapor amount is stopped.

  As described above, fluctuations in the water vapor concentration around the substrate S cause variations in film characteristics. In this embodiment, the plasma density is made uniform by forming a plasma space that extends long along the Y direction. Further, by providing the water vapor traps 173 corresponding to both ends of the substrate S in the Y direction, excess water vapor in the vicinity of the peripheral edge of the substrate S is removed. For this reason, the fluctuation | variation of water vapor | steam density | concentration is suppressed. However, a more effective measure is not to generate excessive water vapor in the vacuum chamber 10.

  The water molecules once adsorbed on the wall surface of the vacuum chamber 10 are released from the vacuum chamber 10 at irregular timings and raise the water vapor partial pressure in the chamber. In particular, in the case of continuously forming a film for a long time, if water molecules are first attached to the vacuum chamber 10, the aforementioned risk of liberation always remains during the film formation period. Therefore, in order not to cause such adhesion of water molecules from the beginning, it is preferable that the amount of water vapor introduced into the chamber is gradually increased.

  For the same reason, water vapor is not introduced before the plasma is turned on. That is, the water vapor introduced into the vacuum chamber 10 without plasma generation spreads from the processing space PS into the vacuum chamber 10 in the form of water molecules and adheres to each part in the chamber. Such water molecules are released from the wall surface after the plasma is turned on, so that the water vapor concentration in the chamber becomes unstable. In order to avoid such a problem, the introduction of water vapor is started after the plasma is turned on.

  Further, when the water vapor concentration rapidly changes in the plasma generation space PL, abnormal discharge (arcing) is likely to occur in the rotating cathodes 51 and 52. In order to prevent this, it is preferable that the water vapor concentration gradually increases. For example, it may take 10 seconds or more to increase the amount equivalent to 1% of the target value of the water vapor partial pressure. For this reason, it may take several minutes from the start of the introduction of water vapor until the water vapor partial pressure reaches the target value.

  After a while until the water vapor amount becomes stable, the scanning movement of the substrate S is started (step S108). That is, the transport mechanism 3 operates to move the carrier 31 from the retracted position toward the sputter source 5 in the X direction so that the lower surface of the substrate S faces the opening 111 above the chimney 11. Thereby, film formation on the substrate S is started. When the substrate S is scanned over the chimney 11 at a constant speed, a film having a constant thickness is formed in the film formation target region FR of the substrate S (scan film formation). The scanning movement of the substrate S may be performed only once, or may be performed a plurality of times by reciprocating movement.

  When the predetermined scanning movement is completed (step S109), the substrate S is carried out to the load lock chamber 20 through the gate 160 (step S110). If it is not necessary to continue film formation, plasma generation is stopped. That is, the supply of the sputtering gas and the reactive gas to the vacuum chamber 10 is stopped, and the voltage application to each part is also stopped (step S111). This completes the film forming process.

  When film formation is continuously performed on another substrate, after the substrate S is discharged in step S110, the process proceeds to step S104, and a new substrate S is carried in. In this case, since the plasma lighting state is maintained, no new gas or voltage is supplied in step S105. By maintaining the plasma lighting state during the replacement of the substrate S, transient fluctuations in the plasma density and the generation of foreign matter caused by the on / off of the plasma are suppressed, and a plurality of substrates S can be controlled. A film having a stable quality can be continuously formed.

  Various methods can be considered when replacing the substrate S. The most basic method is a method of exchanging the substrate by releasing the load lock chamber 20 to the atmosphere after the processed substrate is carried out together with the carrier 31 to the load lock chamber 20. However, this method increases the standby time of the film forming apparatus 1. In order to further increase the productivity, for example, it is conceivable to replace a plurality of substrates previously loaded into the load lock chamber 20 by a transfer robot installed in the load lock chamber 20. Alternatively, a plurality of carriers 31 may be prepared in advance, and a plurality of substrates may be loaded into the load lock chamber 20 in a state where the substrates are respectively set on the carriers 31.

  In addition, the substrate transfer direction is fixed in one direction, and an unprocessed substrate is carried into the vacuum chamber 10 from one of the gates 160 and 161 provided at both ends of the vacuum chamber 10 to form a film. The substrate may be carried out from the other gate.

  In addition, when film formation is performed on a long sheet-like substrate, a take-up roller that takes up the substrate wound in a roll shape and the processed substrate may be installed inside the vacuum chamber 10. Alternatively, an unprocessed substrate may be sent from one of the gates 160 and 161 at a constant speed to form a film, and the substrate after film formation may be sent from the other gate and wound up outside. .

  FIG. 8 is a diagram illustrating an example of a change in the partial pressure of water vapor in the atmosphere in the film forming process. Time T0 corresponds to the time after execution of step S104 in FIG. 6. At this time, the substrate S is carried into the vacuum chamber 10, and the inside of the vacuum chamber 10 is depressurized to a predetermined pressure. In this state, supply of the sputtering gas and application of voltage are started at time T1, so that the plasma is turned on in the plasma space PL. Thereby, the pre-sputtering which cleans the target surface by sputtering is started.

  Thereafter, introduction of a reactive gas containing water vapor is started at time T2 (step S106), whereby the water vapor partial pressure in the atmosphere gradually increases. When a large amount of water vapor is introduced at once, excessive water vapor leaking from the plasma space PL may adhere to the wall surface of the processing chamber 10. In order to avoid this, the amount of water vapor introduced is gradually increased while detecting the amount of water vapor (or water vapor partial pressure) in the atmosphere.

  When the water vapor partial pressure reaches a predetermined value at time T3, the increase in the water vapor amount is stopped (step S107). As shown in FIG. 8, the “predetermined value” of the water vapor amount (water vapor partial pressure) at this time is originally The value is lower than the target value at the time of film formation. This is because there is a certain time lag from when the amount of water vapor is increased until the change is detected, so even if the increase is stopped when the target value is reached, a large overshoot may occur. .

  In the present embodiment, a change in the partial pressure of water vapor is caused by the effect of the sputter source 5 that combines magnetron plasma and inductively coupled plasma and the water vapor trap 173 that removes excess water vapor at the edge of the substrate. Rate) is reduced. However, once excess water vapor due to overshoot is once released into the vacuum chamber 10, there may be a case where the influence cannot be completely removed. In order to avoid this, the increase in the amount of water vapor is stopped before the detected water vapor partial pressure reaches the target value.

  Due to the detection time delay, the water vapor partial pressure after the amount of water vapor introduced is fixed reaches a higher value than when the increase is stopped. Even if this value does not coincide with the target value, in the present embodiment, the sensitivity of the film characteristics to the partial pressure of water vapor is low, so that the influence on the film quality is small.

  After the water vapor partial pressure is substantially stabilized at time T4, film formation is started by scanning movement of the substrate S at time T5. Since the water vapor partial pressure is stable at this point, the quality of the formed film is also stable.

  As described above, in the film forming apparatus 1 of this embodiment, the opening 174 that opens between the end portion of the substrate S (more strictly, the film formation target region FR) and the side wall surfaces 101 and 102 of the vacuum chamber 10 is provided. Then, the water vapor in the atmosphere is removed by the water vapor trap 173. This prevents the water vapor adhering to the side wall surfaces 101 and 102 from being liberated and increasing the water vapor concentration in the vicinity of the edge of the substrate S. The effects of the water vapor trap 173 include the effect of preventing the water vapor supplied to the processing space PS from leaking out and adhering to the side wall surfaces 101 and 102 and the water vapor liberated from the side wall surfaces 101 and 102 from the substrate S. And the effect of preventing access to

  Thereby, the deterioration of the film characteristics due to the increase in the water vapor concentration in the vicinity of the edge with respect to the central part of the substrate S is suppressed, and a film with excellent in-plane uniformity of characteristics can be formed.

  In this embodiment, when one direction (Y direction) is set as a reference direction, the same direction as the magnetron plasma generated by the rotating cathodes 51 and 52 and the magnet units 53 and 54 extending long along the reference direction. By combining with the inductively coupled plasma generated by the long and low inductance inductively coupled antenna 57, a uniform and high density plasma is generated in the plasma space PL extending long in the reference direction. Thereby, the dispersion | variation in the film | membrane characteristic in a reference direction is suppressed, and the in-plane uniformity of a characteristic becomes still better.

  In a plasma generation process using a combination of a low-inductance antenna and a magnetron rotary cathode, high-density plasma can be generated locally and uniformly at low temperature and low potential. By generating plasma intensively in the vicinity of the target, the target can be sputtered at a high rate, while damage to the substrate S can be suppressed. Thereby, a uniform and good quality film can be formed on the surface of the substrate S.

  Since the water vapor concentration is made uniform by the water vapor trap 173 in the same reference direction, the uniformity of the film characteristics in the reference direction is extremely good. In this state, the substrate S is scanned and moved in a direction (X direction) orthogonal to the reference direction, whereby a film with excellent in-plane uniformity of characteristics can be formed over the entire film.

  In order to suppress the influence of the increase in water vapor concentration caused by the liberation of water vapor from the side wall surface of the vacuum chamber 10, it is also conceivable to keep the substrate S and the chamber wall surface away from each other. However, this increases the size of the vacuum chamber and increases the capacity to be evacuated, which is not realistic. In other words, with the above configuration, the proximity of the substrate and the chamber wall surface is allowed. As a result, it is possible to suppress an increase in the size of the vacuum chamber and to reduce the size and cost of the entire apparatus.

  As described above, in the film forming apparatus 1 of this embodiment, the vacuum chamber 10 functions as the “processing chamber” of the present invention, and the transport mechanism 3, particularly the carrier 31, functions as the “substrate holding means” of the present invention. doing. In the present embodiment, the base member 511 (521) of the rotating cathode 51 (52) and the rotation driving unit 55 (56) function as a “target holding unit” of the present invention. In the above embodiment, the Y direction corresponds to the “reference direction” of the present invention.

  Further, in the above embodiment, the inductively coupled antenna 57, the magnet units 53 and 54, the power supply unit 8 and the like function as a “plasma generating means” of the present invention, and of these, the magnet units 53 and 54 are the present invention. The “magnetic field forming unit”, the magnetron power source 81 correspond to the “voltage application unit” of the present invention, and the high frequency power source 82 corresponds to the “high frequency power source” of the present invention.

  Moreover, in the said embodiment, the reactive gas supply part 6 and the sputter | spatter gas supply part 7 function as the "gas supply means" of this invention integrally. The water vapor trap 173 and the vacuum pump 171 function as the “water vapor removing means” and the “exhaust means” of the present invention, respectively. Further, the opening 174 and the opening 172 correspond to the “intake port” and the “exhaust port” of the present invention, respectively. Further, the control unit 19, the probe 191, the spectroscope 192, the mass spectrometer 195, and the like function as a “water vapor amount adjusting unit” of the present invention.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, two sets of magnetron type rotary cathodes are provided facing the processing space PS, but one set of rotary cathodes may be provided. Moreover, although the utilization efficiency of the target is lower than that of the rotating cathode, the present invention can also be applied to an apparatus using a flat cathode.

  In the above embodiment, the water vapor trap 173 is provided on the bottom surface 103 of the vacuum chamber 10. Instead, a water vapor trap may be provided on the side wall surfaces 101 and 102 of the vacuum chamber 10. In this case, it is necessary to avoid the water vapor supplied in the chamber from being excessively absorbed and the water vapor partial pressure in the plasma space PL from becoming unstable. For this reason, it is necessary to further examine the location of the water vapor trap and the opening of the gate valve.

  Further, the film forming apparatus 1 of the above embodiment includes a chimney 11 that opens upward above the sputtering source 5, and forms an ITO film on the lower surface of the substrate S that passes through the upper part of the opening. However, the positional relationship between the sputtering source and the substrate that is the film formation target is not limited to this. For example, a configuration in which a sputtering source is disposed on the side of a substrate transported in a substantially vertical posture may be employed. Further, for example, the film may be formed on the upper surface of the substrate transported under the sputter source. In this case, contaminants such as small particles generated and released on the target surface by sputtering fall on the substrate surface. It is preferable to take measures to prevent this.

  In the above-described embodiment, one set of the sputtering source 5 that performs sputtering in the plasma space PL extending along the Y direction is provided, and film formation is performed by scanning and moving the substrate S in the X direction at a position facing the sputtering source 5. This is a so-called scan film forming apparatus. Apart from this, there is an apparatus in which a plurality of sputter sources are arranged in a direction orthogonal to the direction in which the plasma space is formed, and film formation (stationary film formation) is performed with the substrate stationary. The present invention can also be applied to such an apparatus.

  In the above description, the ITO film is exemplified as the film forming material, but the film forming material is not limited to this. Particularly in the formation of an amorphous metal oxide film, the film forming apparatus 1 of the present embodiment functions effectively.

  As described above, the specific embodiments have been described by way of example. In the present invention, the plasma generating means includes a magnetic field forming unit that forms a magnetic field near the surface of the target, a voltage applying unit that applies a voltage to the target, And may generate magnetron plasma in the plasma space. According to such a configuration, since the plasma space can be concentrated near the surface of the target, a high sputtering rate by high-density plasma can be obtained. Thereby, the uniformity of the film to be formed and the film formation rate can be improved.

  In addition, for example, the substrate holding unit may be configured to rotate while holding the axial direction of the target formed in a cylindrical shape so as to coincide with the reference direction, and the magnetic field forming unit may be disposed in the target cylinder. According to such a configuration, since the position of the target surface facing the plasma space changes due to the rotation, the problem that only a specific portion of the target is sputtered hardly occurs. For this reason, the utilization efficiency of a target becomes high and the tolerance with respect to abnormal discharges, such as arcing, also becomes high.

  In this case, a plurality of cylindrical targets may be provided with their axial directions parallel to each other. By doing so, the plasma can be concentrated in a more limited space, and the density of the target particles can also be increased. Therefore, the characteristics of the film to be formed can be further uniformed and the film formation rate can be improved.

  Further, for example, the plasma generating means may include an inductively coupled antenna that generates an inductively coupled electric field in the plasma space and a high frequency power source that supplies high frequency power to the inductively coupled antenna. According to such a configuration, it is possible to generate plasma at a relatively low temperature and low voltage, and damage to the substrate due to the plasma can be suppressed. In addition, since the shape of the plasma space can be controlled by the antenna shape, it is suitable for use in generating plasma only in a specific range. In particular, the combined use of inductively coupled plasma and magnetron plasma with a low inductance inductively coupled antenna can generate a uniform and high density plasma with a controlled shape, which is particularly suitable for uniform film formation. It will be a thing.

  Further, for example, the water vapor absorbing means may be configured to adsorb the water vapor taken in from the intake port by a cooled low temperature member. A cryopump is a device that operates on such a principle, and can create a high vacuum state at a high exhaust speed. For this reason, it is possible to remove the water vapor in the processing chamber at a high speed, and the fluctuation of the water vapor concentration around the substrate can be strongly suppressed.

  In this case, the temperature of the low temperature member is preferably, for example, 80K to 130K. According to such a configuration, water vapor (water molecules) can be strongly adsorbed, while adsorption of other reactive gas and sputtering gas can be suppressed. That is, it becomes possible to selectively remove only water vapor.

  Further, for example, an exhaust unit that exhausts the atmosphere in the processing chamber from an exhaust port provided between the pair of intake ports and adjusts the pressure in the internal space to a predetermined film formation pressure may be further provided. By separately providing the exhaust means and the water vapor absorbing means, it is possible to independently adjust the pressure in the internal space and the water vapor concentration.

  Further, for example, the substrate holding means may transport the substrate in a direction orthogonal to the reference direction and parallel to the surface of the substrate. According to such a configuration, a uniform film formation in the reference direction is continuously performed in a direction orthogonal to the reference direction, whereby a film formation with excellent in-plane uniformity can be performed.

  Further, for example, a water vapor amount adjusting means for detecting the water vapor amount in the internal space and adjusting the water vapor amount in the gas based on the detection result may be further provided. Since the quality of the film changes depending on the amount of water vapor during film formation, it is possible to perform film formation with stable quality by adjusting the introduction amount while detecting the amount of water vapor.

  The present invention can be particularly suitably used for the purpose of forming an amorphous ITO film with good in-plane uniformity of characteristics, but is not limited to this, and plasma sputtering film forming techniques using a gas containing water vapor are generally not limited thereto. It is possible to apply.

DESCRIPTION OF SYMBOLS 1 Film-forming apparatus 3 Conveyance mechanism 6 Reactive gas supply part (gas supply means)
7 Sputtering gas supply unit (gas supply means)
8 Power supply unit (plasma generating means)
10 Vacuum chamber (processing chamber)
19 Control unit (water vapor amount adjusting means)
31 Carrier (substrate holding means)
51, 52 Rotating cathode (target holding means, plasma generating means)
53, 54 Magnet unit (magnetic field forming unit, plasma generating means)
55, 56 Rotation drive part (target holding means)
57 Inductively coupled antenna (plasma generating means)
81 Magnetron power supply (voltage application unit, plasma generation means)
82 High frequency power supply (plasma generating means)
171 Vacuum pump (exhaust means)
172 Opening (exhaust port)
173 Water vapor trap (water vapor removal means)
174 Opening (uptake port)
191 probe (water vapor amount adjusting means)
195 Mass spectrometer (water vapor amount adjusting means)
511, 521 Base member (target holding means)
S substrate

Claims (10)

A processing chamber having an internal space surrounded by wall surfaces;
A substrate holding means for holding the substrate in a state in which the film formation target region on the surface of the substrate is exposed in the processing chamber;
When the length of the film formation target region in one reference direction parallel to the surface of the substrate is an effective length, a target whose length in the reference direction is longer than the effective length is set in the processing chamber. Target holding means for holding and facing the film formation target region;
Plasma generating means for generating plasma in the vicinity of a band-shaped region having a length in the reference direction that is longer than the effective length and facing the film formation target region of the surface region of the target;
Gas supply means for supplying a gas containing water vapor to the plasma space in which the plasma is generated in the internal space of the processing chamber;
Water vapor removing means for removing water vapor from the atmosphere in the processing chamber outside the plasma space;
The water vapor removing means takes in water vapor from a pair of intake ports provided in the processing chamber by making the positions in the reference direction different from each other, and at each of the intake ports, at least a part of the opening is the reference The film-forming apparatus which exists outside the edge part of the said film-forming object area | region in a direction.   The said plasma generation means has a magnetic field formation part which forms a magnetic field in the surface vicinity of the said target, and a voltage application part which applies a voltage to the said target, The magnetron plasma is generated in the said plasma space. Film forming equipment.   The said board | substrate holding means rotates while making the axial direction of the said target formed in a cylinder correspond with the said reference direction, and the said magnetic field formation part is arrange | positioned in the cylinder of the said target. Film forming equipment.   The film-forming apparatus according to claim 3, wherein a plurality of cylindrical targets are provided with their axial directions parallel to each other.   5. The film forming apparatus according to claim 1, wherein the plasma generating unit includes an inductively coupled antenna that generates an inductively coupled electric field in the plasma space, and a high frequency power source that supplies high frequency power to the inductively coupled antenna. .   6. The film forming apparatus according to claim 1, wherein the water vapor absorbing means adsorbs the water vapor taken in from the intake port by a cooled low temperature member.   The film forming apparatus according to claim 6, wherein the temperature of the low temperature member is 80K to 130K.   8. The exhaust system according to claim 1, further comprising an exhaust unit configured to exhaust an atmosphere in the processing chamber from an exhaust port provided between the pair of intake ports to adjust a pressure in the internal space to a predetermined film formation pressure. A film forming apparatus according to claim 1.   The film forming apparatus according to claim 1, wherein the substrate holding unit transports the substrate in a direction perpendicular to the reference direction and parallel to the surface of the substrate.   The film forming apparatus according to claim 1, further comprising a water vapor amount adjusting unit that detects a water vapor amount in the internal space and adjusts a water vapor amount in the gas based on a detection result.

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