JP2015170680A - Cvd apparatus and cvd method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower cleaning frequency of a CVD apparatus and to reduce consumption of cleaning gas.SOLUTION: The CVD apparatus includes: a chamber; a structure for regulating processing space for CVD processing in the chamber; a raw material gas supply unit for supplying raw material gas including predetermined gaseous species to the processing space; an excitation unit for exciting the raw material gas in the processing space; an adhesion suppressing gas supply unit for supplying adhesion suppressing gas for suppressing adhesion of active species generated from the raw material gas to the structure from a plurality of discharge ports two-dimensionally distributed on a wall surface surrounding the processing space of the structure to the processing space; and a mechanism for opposing a base material to be processed to the processing space. The adhesion suppressing gas includes the predetermined gaseous species.

Description

  The present invention relates to a technique for forming a film by a CVD process.

In recent years, plasma CVD apparatuses that form a thin film on a substrate by converting a reaction gas into plasma and depositing ions, radicals, and the like in the plasma on the surface of the substrate have become widespread. The reaction product by plasma CVD is deposited not only on the substrate but also on the wall surface of the processing chamber. When the film formed on the wall surface or the like becomes thick due to the film formation process for a long time, the flakes may peel off from the film and adhere to the substrate, which may cause defects. In order to remove the thin film deposited on the wall surface of the processing chamber, usually, the substrate is taken out from the processing chamber, and a cleaning gas such as NF ₃ gas is introduced into the processing chamber to deposit the reaction product deposited on the wall surface of the processing chamber. A cleaning process for removing objects is performed. After the cleaning is completed, it is necessary to remove the cleaning gas by exhausting before resuming the film forming process. For this reason, there exists a problem that the operation rate of an apparatus falls. In addition, NF ₃ gas is subject to regulation in the revised protocol of the Kyoto Protocol because it is a global warming substance.

  In Patent Document 1, plasma is generated in a plasma generation chamber independent of a processing chamber in which a substrate is disposed, the generated plasma is introduced into the processing chamber by a plasma introduction nozzle, and the introduced plasma reacts from a reactive gas supply nozzle. A film forming apparatus for forming a thin film on a substrate by supplying a gas (raw material gas) is shown.

  The plasma introduction nozzle protrudes from a wall portion that separates the plasma generation chamber and the processing chamber toward the substrate disposed in the processing chamber, and a discharge port that faces the substrate opens at the tip. A reactive gas or the like as an anti-adhesion gas for preventing the reaction product from adhering to the outer peripheral portion of the nozzle is supplied (spouted) to the substrate along the outer peripheral surface of the nozzle. An adhesion prevention gas supply port is provided. In the film forming process, the apparatus introduces plasma in the plasma generation chamber from the plasma introduction nozzle into the processing chamber, supplies the reaction gas from the reaction gas supply nozzle, and supplies the adhesion prevention gas from the adhesion prevention gas supply port. By supplying, a film made of a reaction product is formed on the surface of the substrate facing the plasma introduction nozzle.

  The adhesion prevention gas ejected from the adhesion prevention gas supply port flows to the substrate side along the outer peripheral surface of the plasma introduction nozzle, and is then supplied so as to surround the plasma introduced from the plasma introduction nozzle into the processing chamber. Thereby, the adhesion of the reaction product to both the outer peripheral surface of the plasma introduction nozzle and the wall surface of the processing chamber is suppressed, and the operating rate of the apparatus is improved.

JP 2001-279448 A

  However, an apparatus that generates plasma in a processing space and forms a film on a substrate by a CVD process in the processing space does not include a plasma introduction nozzle that ejects plasma into the processing space. For this reason, the method of Patent Document 1 cannot improve the operation rate of the apparatus by reducing the cleaning frequency and reduce the amount of cleaning gas used.

  The present invention has been made to solve these problems, and it is an object of the present invention to provide a technique capable of reducing the frequency of cleaning and reducing the amount of cleaning gas used in a film forming technique for forming a film by a CVD process. And

  In order to solve the above problem, a CVD apparatus according to a first aspect includes a chamber, a structure that defines a processing space for CVD processing in the chamber, and a raw material containing a predetermined gas species in the processing space. A source gas supply unit that supplies a gas; an excitation unit that excites the source gas in the processing space; and an adhesion suppression gas for suppressing adhesion of active species generated from the source gas to the structure. An adhesion suppression gas supply unit that supplies the processing space from a plurality of discharge ports that are two-dimensionally distributed on a wall surface that surrounds the processing space of the structure, and a mechanism that causes the substrate to be processed to face the processing space. The adhesion suppression gas includes the predetermined gas species.

  The CVD apparatus according to the second aspect is the CVD apparatus according to the first aspect, wherein an interval between peripheral portions of the discharge ports adjacent to each other among the plurality of discharge ports is 1 cm or less.

  The CVD apparatus according to the third aspect is the CVD apparatus according to the first or second aspect, wherein an opening diameter of the plurality of discharge ports is 10 times or less of an average free path of the source gas.

  A CVD apparatus according to a fourth aspect is the CVD apparatus according to any one of the first to third aspects, wherein the structure includes an internal space, and the plurality of discharge ports are connected to the processing space. The adhesion suppression gas supply unit communicates with the internal space, and supplies the adhesion suppression gas to the processing space from the plurality of discharge ports by supplying the adhesion suppression gas to the internal space.

  The CVD apparatus according to the fifth aspect is the CVD apparatus according to any one of the first to fourth aspects, wherein the gas pressure at the plurality of discharge ports is 1.89 times the gas pressure in the processing space. That's it.

  A CVD apparatus according to a sixth aspect is the CVD apparatus according to any one of the first to fifth aspects, wherein a partial pressure ratio of each gas included in the adhesion suppression gas is included in the source gas. It is the same as the gas partial pressure ratio.

  A CVD apparatus according to a seventh aspect is the CVD apparatus according to any one of the first to sixth aspects, wherein the source gas supply unit is configured to supply the processing space from an ejection port different from the plurality of ejection ports. To supply the raw material gas.

  A CVD apparatus according to an eighth aspect is the CVD apparatus according to any one of the first to seventh aspects, wherein a supply amount per unit time of the source gas is a unit amount per unit time of the adhesion suppression gas. More than supply.

  A CVD apparatus according to a ninth aspect is the CVD apparatus according to any one of the first to eighth aspects, wherein the excitation unit is a plasma generation unit that generates plasma of the source gas in the processing space. is there.

  A CVD apparatus according to a tenth aspect is the CVD apparatus according to the ninth aspect, wherein the plasma generator is provided in the processing space and generates inductively coupled plasma of the source gas in the processing space. Provide an antenna.

  A CVD apparatus according to an eleventh aspect is the CVD apparatus according to the tenth aspect, wherein the high-frequency antenna is a high-frequency antenna provided in the chamber and made of a conductor having a number of turns of less than one turn.

  A CVD method according to a twelfth aspect includes a first step in which a substrate to be processed is opposed to the processing space of a chamber including a structure that defines a processing space for CVD processing, and the first step in parallel with the first step. A second step of exciting a gas in the processing space; a third step of exciting the source gas in parallel with the first and second steps in the processing space; and the structure of the active species generated from the source gas The treatment space in parallel with the first and second steps is supplied from a plurality of discharge ports that two-dimensionally distribute an adhesion suppression gas for suppressing adhesion to the body on the wall surface surrounding the treatment space of the structure. And a fourth step of supplying the adhesion suppression gas, wherein the adhesion suppression gas includes the predetermined gas species.

  The CVD method according to the thirteenth aspect is the CVD method according to the twelfth aspect, wherein the third step and the fourth step are performed in parallel.

  The CVD method according to the fourteenth aspect is the CVD method according to the twelfth aspect, wherein the third step and the fourth step are sequentially performed.

  According to any of the first to fourteenth aspects of the present invention, the adhesion suppression gas from the plurality of discharge ports distributed two-dimensionally on the wall surface surrounding the processing space of the structure defining the processing space for CVD processing in the chamber. Is supplied to the processing space. The adhesion suppression gas contains a predetermined gas species included in the source gas. The adhesion suppression gas supplied to the processing space collides with active species such as ions and radicals of the source gas and changes its direction. Therefore, the active species can be prevented from adhering to the wall surface surrounding the processing space of the structure that defines the processing space, and the frequency of cleaning the structure and the like can be reduced. Since the adhesion suppression gas contains a predetermined gas species included in the source gas, the amount of the cleaning gas used can be reduced.

It is a YZ side view which shows typically schematic structure of the plasma processing apparatus which concerns on embodiment. FIG. 2 is an XZ side view schematically showing a schematic configuration of the plasma processing apparatus of FIG. 1. It is a perspective view of the structure which prescribes | regulates the process space of the plasma processing apparatus of FIG. It is a schematic diagram which shows the state which the adhesion suppression gas has suppressed adhesion of the active species of the source gas to the wall surface facing the processing space of the structure.

<1. Overall Configuration of Plasma CVD Apparatus 100>
FIG. 1 is a YZ side view schematically showing a schematic configuration of a plasma CVD apparatus 100 according to the embodiment. FIG. 2 is an end view as seen from the AA cross section of FIG. 1 and is an XZ side view schematically showing a schematic configuration of the plasma CVD apparatus 100. FIG. 3 is a perspective view showing the structure 5 that defines the processing space V <b> 1 of the plasma CVD apparatus 100. In the drawings, for the purpose of clarifying the directional relationship, XYZ orthogonal coordinate axes with the Z axis as the vertical axis and the XY plane as the horizontal plane are appropriately attached.

  The plasma CVD apparatus 100 performs CVD on plasma-enhanced chemical vapor deposition (CVD) on a substrate 9 (for example, a semiconductor substrate for a solar cell, also referred to as a “base material”) that is an object of film deposition. An apparatus for forming a film (for example, a protective film).

  The plasma CVD apparatus 100 holds a processing chamber 1 in which a processing space V1 is formed and a substrate 9 (specifically, a substrate 9 disposed on a carrier 90) and performs a predetermined process along a predetermined transport path. A holding transport unit 2 that transports the substrate in the transport direction (the + Y direction in the figure), a heating unit 3 that heats the transported substrate 9, a plasma generating unit 4 that generates plasma in the processing space V1, and a processing space V1 are defined. And the structure 5 to be provided.

  In addition, the plasma CVD apparatus 100 includes gas supply units 60 to 63 that supply a gas to the processing space V <b> 1 and an exhaust unit 7 that exhausts the gas from the processing chamber 1. In addition, the plasma CVD apparatus 100 includes a control unit 8 that controls each of the above components.

<Processing chamber 1>
A processing chamber (also referred to as “vacuum chamber” or simply “chamber”) 1 is a hollow member having a processing space V1 therein. Here, the processing space V <b> 1 is a space where plasma CVD processing is performed by an inductively coupled antenna 41 described later. In the present embodiment, one processing space V <b> 1 is formed by the structure 5.

  The top plate 11 of the processing chamber 1 is arranged so that the lower surface 111 thereof is in a horizontal posture, and the inductively coupled antenna 41 and the structure 5 (both will be described later) from the lower surface 111 toward the processing space V1. Is protruding. A heating unit 3 is disposed near the bottom plate of the processing chamber 1. On the upper side of the heating unit 3, a transport route (a route along the Y direction in the drawing) of the substrate 9 by the holding transport unit 2 is defined. Further, on the side wall on the ± Y side of the processing chamber 1, a carry-in / out port (not shown) that is opened and closed by a gate valve, for example, is provided.

<Holding and conveying unit 2>
The holding and conveying unit 2 holds the carrier 90 in a horizontal posture, and conveys the carrier 90 along the conveyance path via the carry-in / out opening formed in the processing chamber 1. On the upper surface of the carrier 90, a plurality of substrates 9 (a total of three substrates 9 along the Y direction in this embodiment), which are objects to be filmed, are disposed. In addition, a processing space V1 in which plasma CVD processing is performed is formed above the transport path and at a position facing the plurality of substrates 9 transported along the transport path.

  Specifically, the holding and conveying unit 2 includes a pair of conveying rollers 21 arranged to face each other with the conveying path interposed therebetween, and a driving unit (not shown) that rotates and synchronizes these rollers. For example, a plurality of pairs of the transport rollers 21 are provided along the extending direction (Y direction in the drawing) of the transport path. In this configuration, each carrier roller 21 rotates while contacting the lower surface of the carrier 90, whereby the carrier 90 is conveyed along the conveyance path. As a result, the substrate 9 held by the carrier 90 is moved relative to the processing space V 1 having the inductively coupled antenna 41.

  The holding conveyance unit 2 causes the substrate 9 to face the processing space V1 in a portion (bottom wall portion 52 described later of the structure 5) of the conveyance path of the substrate 9 that faces the processing space V1. The holding and conveying unit 2 holds the position of the substrate 9 in the facing direction with respect to the structure 5 when the substrate 9 faces the processing space V1. For example, a stage mechanism including a fixing mechanism that is fixed to a portion of the lower surface 111 of the top plate 11 that faces the processing space V1 and that can detachably hold the substrate 9 may be used instead of the holding and transporting unit 2. Good. Further, as the substrate 9, a film-like substrate extending in the conveyance direction of the holding conveyance unit 2 may be adopted. In that case, the holding conveyance unit 2 does not include the carrier 90, and each conveyance roller 21 is in direct contact with both ends of the back surface of the substrate (the main surface opposite to the main surface to be formed). May be conveyed.

<Heating unit 3>
The heating unit 3 is a member that heats the substrate 9 that is held and conveyed by the holding and conveying unit 2, and is disposed below the holding and conveying unit 2 (that is, below the conveyance path of the substrate 9). The heating part 3 can be comprised with a ceramic heater, for example. The plasma CVD apparatus 100 may further be provided with a mechanism for cooling the substrate 9 and the like held by the holding and conveying unit 2 after the CVD process.

<Plasma generator 4>
The plasma generator 4 generates plasma in the processing space V1. The plasma generation unit 4 includes a plurality (four in this embodiment) of inductively coupled antennas 41 that are inductively coupled high frequency antennas. Specifically, each inductively coupled antenna 41 is formed by bending a metal pipe-shaped conductor into a U shape with a dielectric such as quartz. The plasma generator 4 is an exciter that excites the source gas in the processing space V1 to turn it into plasma.

  As shown in FIG. 3, the plurality of inductively coupled antennas 41 are arranged at intervals (preferably at equal intervals) along a predetermined direction, and are fixed to the top plate 11. A part of the inductively coupled antenna 41 on the holding and conveying unit 2 side (including a U-shaped bottom portion) protrudes from the bottom wall 52 of the structure 5 to the holding and conveying unit 2 side. The plurality of inductively coupled antennas 41 are in a direction crossing the transport direction (Y direction) of the substrate 9 (particularly preferably, a direction orthogonal to the transport direction of the substrate 9 (X direction as shown in the figure) in the YZ side view. )).

  In the illustrated example, four inductively coupled antennas 41 are provided along the conveyance direction of the substrate 9, but the number of inductively coupled antennas 41 is not necessarily four, The number can be appropriately selected according to the dimensions and the like. The inductively coupled antennas 41 may be arranged in a matrix or a staggered pattern. One inductively coupled antenna 41 may be provided according to the dimensions of the processing chamber 1 and the like.

  One end of each inductively coupled antenna 41 is connected to a high frequency power supply 44 through a power feeder 42 and a matching box 43. The other end of each inductively coupled antenna 41 is grounded. In this configuration, when a high frequency current (specifically, for example, a high frequency current of 13.56 MHz) is supplied from the high frequency power supply 44 to each inductive coupling antenna 41, the electric field around the inductive coupling antenna 41 (high frequency induction electric field). ) Are accelerated, and plasma (Inductively Coupled Plasma (ICP)) is generated.

  As described above, the inductively coupled antenna 41 has a U shape. Such a U-shaped inductively coupled antenna 41 corresponds to an inductively coupled antenna having less than one turn and has a lower inductance than an inductively coupled antenna having one or more turns. The high frequency voltage generated in the plasma is reduced, and the high frequency fluctuation of the plasma potential accompanying the electrostatic coupling to the generated plasma is suppressed. For this reason, excessive electron loss accompanying the plasma potential fluctuation to the ground potential is reduced, and the plasma potential can be suppressed particularly low. Such inductive coupling type high frequency antennas are disclosed in Japanese Patent No. 3836636, Japanese Patent No. 3836866, Japanese Patent No. 44451392, and Japanese Patent No. 4852140.

  In place of the inductively coupled antenna 41, a coiled inductively coupled antenna having one or more turns may be employed. Further, instead of the inductively coupled antenna 41, a plasma generator that generates capacitively coupled plasma between parallel electrodes facing each other may be employed. In addition, a configuration in which high frequency power is supplied to a coiled antenna wound outside the processing chamber 1 to generate inductively coupled plasma in the processing space V may be employed as the plasma generating unit.

<Structure 5>
The structure 5 is fixed to the top plate 11 so as to face the transport path of the substrate 9. The structure 5 includes a pair of side shields (“earth shield”) 51 and a bottom wall portion 52 that face each other. The pair of side shields 51 are grounded and include a pair of inner peripheral walls 51a, a pair of outer peripheral walls 51b, and a pair of flange portions 51c. Each of the pair of inner peripheral walls 51a, the pair of outer peripheral walls 51b, the pair of flange portions 51c, and the bottom wall portion 52 is a plate-like member that extends in the direction (X direction) across the transport path of the substrate 9. The both ends of each X axis are connected to the walls of both ends of the X axis of the processing chamber 1. The normal direction of the main surfaces of the pair of inner peripheral walls 51a and outer peripheral walls 51b is the transport direction (Y direction) of the substrate 9, and the pair of inner peripheral walls 51a and outer peripheral walls 51b are plate-like bodies perpendicular to the transport path. is there. Moreover, the normal direction of the main surface of the bottom wall part 52 and a pair of flange part 51c is a Z direction, and the bottom wall part 52 and a pair of flange part 51c are plate-shaped bodies parallel to an XY plane. is there.

  The pair of inner peripheral walls 51a are opposed to each other and are erected from both ends of the bottom wall 52 in the Y direction on the holding and conveying unit 2 side (−Z direction). The pair of inner peripheral walls 51a and the bottom wall portion 52 form a wall surface surrounding the processing space V1 of the structure 5 (a wall surface facing the processing space V1). The width of the processing space V1 in the transport direction (Y direction) is the width between the pair of inner peripheral walls 51a.

  The pair of outer peripheral walls 51b are spaced from the pair of inner peripheral walls 51a in the transport direction (Y direction) of the substrate 9 with the pair of inner peripheral walls 51a interposed between the top plate 11 and the holding transport unit 2 side (-Z Direction).

  The heights of the tips of the pair of inner peripheral walls 51a and the pair of outer peripheral walls 51b are set to be higher than the tips of the inductively coupled antenna 41 (the U-shaped bottom) and substantially equal to each other. Yes.

  Of the pair of inner peripheral walls 51a and the pair of outer peripheral walls 51b, two sets of inner peripheral walls 51a and outer peripheral walls 51b facing each other are provided. The ends of one set of the inner peripheral wall 51a and the outer peripheral wall 51b of the two sets of the inner peripheral wall 51a and the outer peripheral wall 51b are connected to one of the pair of flange portions 51c, and the other set of the inner peripheral wall 51a and the outer peripheral wall. The tip of the wall 51b is connected to the other flange portion 51c.

  Of the end portions in the Y direction of the pair of flange portions 51c, each end portion on the processing space V side is connected to the front end portion of each inner peripheral wall 51a, and the front end portion of each outer peripheral wall 51b is connected to each flange portion 51c. It is connected to the middle part in the Y direction. As a result, of the ends in the Y direction of the pair of flange portions 51c, the ends not connected to the inner peripheral wall 51a are arranged on the opposite side of the outer peripheral wall 51b from the processing space V in the Y direction. It extends beyond.

  Accordingly, each of the pair of side shields 51 includes an inner peripheral wall 51a, an outer peripheral wall 51b, and a flange portion 51c, and has a double structure including the inner peripheral wall 51a and the outer peripheral wall 51b. The pair of side shields 51 is made of aluminum, for example. The space sandwiched between the inner peripheral wall 51a and the outer peripheral wall 51b of the pair of side shields 51 and the space sandwiched between the bottom wall portion 52 and the top plate 11 communicate with each other through an internal space V2 included in the structure 5. doing.

  A plurality of discharge ports 64 that are two-dimensionally distributed are formed on the pair of inner peripheral walls 51a and the bottom wall portion 52 that form a wall surface surrounding the processing space V1 of the structure 5 (a wall surface facing the processing space V1). It is open. The plurality of discharge ports 64 communicate the processing space V1 and the internal space V2.

  The interval between the peripheral portions of the discharge ports 64 adjacent to each other among the plurality of discharge ports 64 is preferably set to 1 cm or less. In the example shown in FIG. 3, the plurality of discharge ports 64 are provided so as to form lattice points on each of the pair of inner peripheral walls 51 a and the bottom wall portion 52. In this case, each discharge port 64 is provided such that the longest interval W1 between the peripheral portions of the discharge ports 64 adjacent to each other is preferably 1 cm or less. The plurality of discharge ports 64 are preferably formed over the entire area of both the pair of inner peripheral walls 51 a and the bottom wall part 52, but are formed in part of the pair of inner peripheral walls 51 a and the bottom wall part 52. May be.

  The opening diameter D1 (FIG. 4) of each of the plurality of discharge ports 64 is preferably not more than 10 times the average free path of the source gas supplied to the internal space V2 by the gas supply unit 60 described later. It is set to be.

<Gas supply part 60-63>
The gas supply unit 60 includes an adhesion suppression gas supply source 601, a nozzle 605 that supplies the adhesion suppression gas to the internal space V <b> 2, a pipe 602 that connects the supply source 601 and the nozzle 605, and a pipe 602. The valve 603 is provided.

  The adhesion suppression gas is supplied to the processing space V1 in order to suppress the adhesion of the active species generated from the source gas supplied from the gas supply unit 61 and the gas supply unit 63 described later to the processing space V1 to the structure 5. Gas. More specifically, the adhesion suppression gas supplied to the internal space V <b> 2 of the structure 5 by the gas supply unit 60 is formed so as to be distributed two-dimensionally on the pair of inner peripheral walls 51 a and the bottom wall part 52 of the structure 5. The plurality of discharge ports 64 are supplied to the processing space V1. The adhesion suppression gas contains a predetermined gas species included in the source gas.

  Each of the pair of gas supply units 61 includes a source gas supply source 611, a nozzle 615 that supplies the source gas to the processing space V1, a pipe 612 that connects the source 611 and the nozzle 615, and a path along the pipe 612. And a valve 613 provided in the main body.

The gas supply unit 62 includes a cleaning gas supply source 621 for removing a reaction product of the source gas adhering to the wall surface of the structure 5 in the course of the CVD process in the processing space V1, and the cleaning gas to the processing space V1. The nozzle 625 to supply, the piping 622 which connects the supply source 621 and the nozzle 625, and the valve | bulb 623 provided in the middle of the path | route of the piping 622 are provided. For example, NF ₃ gas or the like is supplied as the cleaning gas.

  The gas supply unit 63 includes a source gas supply source 631, a plurality of nozzles 635 having one end connected to the supply source 631 and the other end positioned above the plurality of inductively coupled antennas 41 in the processing space V1, and a supply source. 631 and a pipe 632 that connects the plurality of nozzles 635 to each other. A valve 633 is provided in the middle of the route of the pipe 632.

  The plurality of nozzles 635 are arranged in a line at intervals and are fixed to the lower surface 111 of the top plate 11 of the processing chamber 1. Specifically, for example, the plurality of nozzles 635 are respectively arranged at positions corresponding to the inductively coupled antenna 41 (for example, positions at the center of both ends of the U-shaped inductively coupled antenna 41), and the top plate 11 is attached airtight. However, the protruding dimension of each nozzle 635 from the lower surface 111 is sufficiently smaller than the protruding dimension of the inductively coupled antenna 41 from the lower surface 111.

The gas supply unit 61 and the gas supply unit 63 supply the source gas to the processing space V1, respectively, but the nozzle 615 of the gas supply unit 61 is farther from the inductively coupled antenna 41 than the nozzle 635 of the gas supply unit 63. Is provided. The nozzle 635 is supplied with a raw material gas that does not corrode the inductively coupled antenna 41 even if it contacts the inductively coupled antenna 41, and the nozzle 615 is preferably a material that is supplied away from the inductively coupled antenna 41. Gas is supplied. Specifically, for example, a mixed gas of nitrogen (N ₂ ) gas and ammonia (NH ₃ ) gas or the like is supplied as a source gas from the plurality of nozzles 635, and as a source gas from each nozzle 615, for example, Silane (SiH ₄ ) gas or the like is supplied. In addition to the source gas, an inert gas that carries the source gas may be supplied from the gas supply units 61 and 63 as a carrier gas.

  Preferably, the opening of the valve 603 and the supply pressure from the supply source 601 are adjusted so that the gas pressure from the nozzle 605 to the plurality of discharge ports 64 is 1.89 times or more the gas pressure in the processing space V1. Is done. The partial pressure ratio of each gas contained in the adhesion suppression gas is preferably set to be the same as the partial pressure ratio of each gas contained in the raw material gas.

  The supply amount of the source gas per unit time is preferably set to be larger than the supply amount of the adhesion suppression gas per unit time.

  The valves 603, 613, 623, 633 are preferably valves that can automatically adjust the flow rate of the gas flowing through the pipes 602, 612, 622, 632, and specifically include, for example, a mass flow controller. Is preferred.

<Exhaust part 7>
The exhaust unit 7 is a high vacuum exhaust system, and specifically includes, for example, a vacuum pump 71, an exhaust pipe 72, and an exhaust valve 73. The exhaust pipe 72 has one end connected to the vacuum pump 71 and the other end connected to the processing space V1. Further, the exhaust valve 73 is provided in the course of the exhaust pipe 72. Specifically, the exhaust valve 73 includes a mass flow controller or the like, for example, and is a valve that can automatically adjust the flow rate of the gas flowing through the exhaust pipe 72. In this configuration, when the exhaust valve 73 is opened while the vacuum pump 71 is operated, the processing space V1 is exhausted.

<Control unit 8>
The control unit 8 is electrically connected to each component included in the plasma CVD apparatus 100 (illustrated schematically in FIG. 1), and controls each of these components. Specifically, the control unit 8 includes, for example, a CPU that performs various arithmetic processes, a ROM that stores programs, a RAM that serves as a work area for arithmetic processes, a hard disk that stores programs and various data files, a LAN, and the like. A data communication unit having a data communication function is connected to each other by a bus line or the like, and is configured by a general computer. The control unit 8 is connected to an input unit composed of a display for performing various displays, a keyboard, a mouse, and the like. In the plasma CVD apparatus 100, a predetermined process is performed on the substrate 9 under the control of the control unit 8.

<2. Operation of plasma processing apparatus>
Subsequently, a flow of processing executed in the plasma CVD apparatus 100 will be described. The process described below is executed under the control of the control unit 8.

  When the carrier 90 on which the substrate 9 is disposed is loaded into the processing chamber 1 through the loading / unloading port of the processing chamber 1, the holding and conveying unit 2 holds the carrier 90. Moreover, the exhaust part 7 exhausts the gas in the processing chamber 1, and makes the processing chamber 1 a vacuum state. Further, at a predetermined timing, the holding and conveying unit 2 starts conveying the carrier 90 (conveying step), and the heating unit 3 starts heating the substrate 9 disposed on the carrier 90.

  When the inside of the processing chamber 1 is in a vacuum state, the gas supply units 61 and 63 start supplying the source gas from the nozzles 615 and 635 to the processing space V1 (source gas supply step), and the gas supply unit 60 is set to the nozzle 605. Thus, the supply of the adhesion suppression gas to the internal space V2 of the structure 5 is started (adhesion suppression gas supply step). The adhesion suppression gas supplied to the internal space V2 is supplied to the processing space V1 from a plurality of discharge ports 64 formed on the wall surface of the structure 5 facing the processing space V1.

  At the same time as the supply of these gases is started, a high-frequency current (specifically, for example, a high-frequency current of 13.56 MHz) is caused to flow from the high-frequency power supply 44 to each inductively coupled antenna 41. Then, electrons are accelerated by the high frequency induction electric field around the inductively coupled antenna 41, and inductively coupled plasma is generated (plasma generating step). When plasma is generated, the source gas in the processing space V1 is turned into plasma, and active species such as radicals and ions of the source gas are generated, and chemical vapor deposition is performed on the transported substrate 9. The substrate 9 with the CVD film formed on the main surface in this way can be used for various electronic devices such as solar cells as a structure for an electronic device.

  During the film forming process of the plasma CVD apparatus 100, the transfer step and the plasma generation step are performed in parallel. The source gas supply step is performed in parallel with the transfer step and the plasma generation step, and the adhesion suppression gas supply step is also performed in parallel with the transfer step and the plasma generation step. The source gas supply step and the adhesion suppression gas supply step may be performed in parallel or sequentially.

  FIG. 4 is a schematic diagram illustrating a state in which the adhesion suppression gas suppresses the adhesion of the active species of the source gas to the wall surface facing the processing space V <b> 1 of the structure 5.

  As shown in FIG. 4, when the adhesion suppression gas is supplied from the gas supply unit 60 to the internal space V <b> 2, the molecules P <b> 1 of the adhesion suppression gas are ejected from the plurality of discharge ports 64 to the processing space V <b> 1. The ejected adhesion-suppressing gas molecules P1 collide with active species P2 such as radicals and ions of the raw material gas generated when the raw material gas supplied from the gas supply units 61 and 63 to the processing space V1 is turned into plasma. The flight direction of the active species P2 is changed. Thereby, it is suppressed that active species P2 adheres to the wall surface of structure 5, and the frequency of cleaning processing can be lowered.

  Moreover, since the adhesion suppression gas contains the gas species contained in the source gas, the amount of the cleaning gas used for the cleaning process can be reduced.

  According to the plasma CVD apparatus 100 according to the present embodiment configured as described above, two-dimensionally on the wall surface surrounding the processing space V1 of the structure 5 that defines the processing space V1 for CVD processing in the processing chamber 1. The adhesion suppression gas is supplied to the processing space V <b> 1 from the plurality of distributed outlets 64. The adhesion suppression gas contains a predetermined gas species included in the source gas. The adhesion suppression gas supplied to the processing space V1 collides with active species such as ions and radicals of the raw material gas and changes its direction. Accordingly, the active species can be prevented from adhering to the wall surface surrounding the processing space V1 of the structure 5 that defines the processing space V1, and the cleaning frequency of the structure 5 and the like can be reduced. Since the adhesion suppression gas contains a predetermined gas species included in the source gas, the amount of the cleaning gas used can be reduced.

  Moreover, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the interval between the peripheral portions of the discharge ports 64 adjacent to each other among the plurality of discharge ports 64 formed in the structure 5 is 1 cm. It is as follows. Therefore, since the discharge ports 64 can be uniformly formed at a high density, the attachment of the active species of the source gas to the wall surface facing the processing space V1 of the structure 5 can be efficiently suppressed.

  Moreover, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the opening diameter D1 of the plurality of discharge ports 64 is 10 times or less the average free path of the source gas. Therefore, clogging of the discharge port 64 due to the raw material gas entering the discharge port 64 can be suppressed.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the structure 5 includes the internal space V2, and the plurality of discharge ports 64 communicate the processing space V1 and the internal space V2. The gas supply unit 60 supplies the adhesion suppression gas from the plurality of discharge ports 64 to the processing space V1 by supplying the adhesion suppression gas to the internal space V2. Therefore, the supply system of the adhesion suppression gas to the internal space V2 by the gas supply unit 60 can be simplified. In addition, the pressure of the adhesion suppression gas can be easily controlled.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the gas pressure at the plurality of discharge ports 64 in the internal space V2 is 1.89 times or more the gas pressure in the processing space V1. . Therefore, the discharge speed of the adhesion suppression gas into the processing space V1 reaches the speed of sound. Accordingly, it is possible to more efficiently suppress the attachment of active species to the structure 5 or the like.

  Moreover, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the partial pressure ratio of each gas included in the adhesion suppression gas is the same as the partial pressure ratio of each gas included in the source gas. It becomes easy to stabilize the partial pressure ratio of the gas in the processing space V1. Therefore, the operating rate of the CVD apparatus can be improved.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the gas supply units 61 and 63 supply the source gas to the processing space V <b> 1 from the discharge ports different from the plurality of discharge ports 64. Therefore, it becomes easy to control the flow rate of the source gas. Further, the source gas and the adhesion suppression gas can be supplied to the processing space V1 in parallel.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the supply amount of the raw material gas per unit time is larger than the supply amount of the adhesion suppression gas per unit time, so that the substrate 9 The film formation efficiency can be improved.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the plasma generation unit 4 generates the plasma of the raw material gas in the processing space V1, so that the film forming process can be performed at a low temperature.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the plasma generating unit 4 is provided in the processing space V1, and generates a source gas inductively coupled plasma in the processing space V1. (Inductively coupled antenna 41). Accordingly, it is possible to increase the plasma density in the processing space V1 and improve the film formation efficiency.

  Moreover, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the inductively coupled antenna 41 is a high-frequency antenna that is provided in the processing chamber 1 and is made of a conductor having less than one turn. Therefore, high density plasma can be generated by a small antenna. By reducing the size of the antenna, the distance between the bottom wall portion 52 of the structure 5 and the inductively coupled antenna 41 can be shortened. Therefore, the adhesion of the active species of the source gas to the inductively coupled antenna 41 can be suppressed by the adhesion suppression gas supplied from the bottom wall portion 52 of the structure 5 to the processing space V1.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the supply process of the source gas to the process space V1 and the supply process of the adhesion suppression gas to the process space V1 are performed in parallel. Since it is performed, the adhesion of the source gas to the structure 5 or the like can be suppressed by the adhesion suppression gas. Thereby, the operation rate of a CVD apparatus can be raised.

  Further, according to the plasma CVD apparatus 100 according to the present embodiment configured as described above, the supply process of the source gas to the process space V1 and the supply process of the adhesion suppression gas to the process space V1 are performed in parallel. Since it is performed, for example, the adhesion suppression gas and the raw material gas can be supplied to the processing space V1 from the same discharge port, and the apparatus configuration can be simplified.

  Although the invention has been shown and described in detail, the above description is illustrative in all aspects and not restrictive. Therefore, embodiments of the present invention can be modified or omitted as appropriate within the scope of the invention.

DESCRIPTION OF SYMBOLS 100 Plasma CVD apparatus 1 Processing chamber 4 Plasma generation part 2 Holding | maintenance conveyance part 21 Conveyance roller 9 Substrate 90 Carrier 41 Inductive coupling type antenna 5 Structure 60-61 Gas supply part

Claims (14)

A chamber;
A structure defining a processing space for CVD processing in the chamber;
A source gas supply unit for supplying a source gas containing a predetermined gas type to the processing space;
An excitation unit for exciting the source gas in the processing space;
Adhesion suppression gas for suppressing the adhesion of active species generated from the source gas to the structure is distributed to the processing space from a plurality of discharge ports that are two-dimensionally distributed on the wall surface surrounding the processing space of the structure. An adhesion suppression gas supply unit for supplying,
A mechanism for causing the substrate to be processed to face the processing space;
With
The adhesion suppression gas is a CVD apparatus including the predetermined gas type. The CVD apparatus according to claim 1,
The CVD apparatus, wherein an interval between peripheral portions of the discharge ports adjacent to each other among the plurality of discharge ports is 1 cm or less. The CVD apparatus according to claim 1 or 2, wherein
The CVD apparatus, wherein an opening diameter of the plurality of discharge ports is 10 times or less of an average free path of the source gas. A CVD apparatus according to any one of claims 1 to 3, wherein
The structure includes an internal space,
The plurality of discharge ports communicate the processing space and the internal space,
The adhesion suppression gas supply unit
A CVD apparatus that supplies the adhesion suppression gas to the processing space from the plurality of discharge ports by supplying the adhesion suppression gas to the internal space. A CVD apparatus according to any one of claims 1 to 4, wherein
The CVD apparatus, wherein a gas pressure at the plurality of discharge ports is 1.89 times or more a gas pressure of the processing space. A CVD apparatus according to any one of claims 1 to 5, wherein
The CVD apparatus, wherein a partial pressure ratio of each gas contained in the adhesion suppression gas is the same as a partial pressure ratio of each gas contained in the source gas. The CVD apparatus according to any one of claims 1 to 6, wherein
The source gas supply unit
A CVD apparatus that supplies the source gas to the processing space from an outlet different from the plurality of outlets. A CVD apparatus according to any one of claims 1 to 7,
The CVD apparatus, wherein a supply amount of the source gas per unit time is larger than a supply amount of the adhesion suppression gas per unit time. A CVD apparatus according to any one of claims 1 to 8, wherein
The said excitation part is a CVD apparatus which is a plasma generation part which generates the plasma of the said source gas in the said process space. The CVD apparatus according to claim 9, wherein
The plasma generation unit includes a high-frequency antenna that is provided in the processing space and generates inductively coupled plasma of the source gas in the processing space. The CVD apparatus according to claim 10, wherein
The high-frequency antenna is
A CVD apparatus, which is a high-frequency antenna provided in the chamber and made of a conductor having less than one turn. A first step of causing a substrate to be processed to face the processing space of a chamber including a structure defining a processing space for CVD processing;
A second step of exciting the gas in the processing space in parallel with the first step;
A third step of exciting the source gas in parallel with the first and second steps in the processing space;
The adhesion suppression gas for suppressing the adhesion of the active species generated from the source gas to the structure is supplied from the plurality of discharge ports distributed two-dimensionally on the wall surface surrounding the processing space of the structure. And a fourth step for supplying the processing space in parallel with the second step,
With
The CVD method, wherein the adhesion suppression gas includes the predetermined gas species. A CVD method according to claim 12, comprising:
A CVD method in which the third step and the fourth step are performed in parallel. A CVD method according to claim 12, comprising:
The third step and the fourth step are CVD methods performed sequentially.

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