KR102430208B1 - Film formation apparatus and film formation method - Google Patents

Abstract

[Problem] To provide a film forming apparatus and a film forming method capable of efficiently forming a silicon hydride film at low cost.
[Solutions] A transfer unit 30 having a rotary table 31 for circulating and conveying the workpiece 10, a target 42 made of a silicon material, and introducing between the target 42 and the rotary table 31 a film forming processing unit 40 having a plasma generator that converts the sputtering gas G1 to be plasma into a plasma and forming a silicon film on the work 10 by sputtering; A hydrogenation unit 50 having a process gas introduction unit 58 for introducing a process gas G2 containing hydrogen gas, and a plasma generator for converting the process gas G2 into plasma, and hydrogenating a silicon film formed on the work 10 . ), and the conveying unit 30 conveys the work 10 so that the work 10 passes through the film forming unit 40 and the hydrogenation unit 50 alternately.

Description

Film-forming apparatus and film-forming method

The present invention relates to a film forming apparatus and a film forming method.

A silicon (Si) film used in an optical film or the like becomes electrically unstable when dangling bonds exist in silicon atoms in the film and the optical properties become unstable, so that hydrogen (H) atoms are bonded to unbonded bonds. It is necessary to make a hydrogen-terminated Si-H film (hereinafter, referred to as a silicon hydride film) by making it stable. As a film forming apparatus for forming a silicon film, there is an apparatus for depositing silicon particles on a substrate by sputtering. Silicon deposited by sputtering is amorphous (amorphous) and has many unbonded losses compared to crystalline silicon, but can be stabilized by hydrogen termination.

In such a film forming apparatus, in a chamber which is an airtight container, the board|substrate is supported and fixed in the position opposing the target of a silicon material. Then, sputtering gas to which hydrogen gas is added is introduced into the chamber, and high-frequency power is applied to the target to make the sputtering gas plasma. By active species generated by the plasma, silicon particles are pushed out of the target and deposited on the substrate. At this time, when the unbonded hand of the silicon atom bonds with the hydrogen atom contained in the sputtering gas, it is hydrogen-terminated.

Patent Document 1: Japanese Patent Laid-Open No. Hei 07-90570

In the case of hydrogen termination together with film formation as described above, the efficiency of bonding between silicon and hydrogen is not good. For this reason, it is necessary to raise the ratio (hydrogen concentration) of the hydrogen gas in sputtering gas. However, if the hydrogen concentration is increased, the possibility that the high concentration hydrogen will explode due to a reaction or heat with oxygen present inside the film forming apparatus increases. Therefore, when increasing the concentration of hydrogen to be used, safety is ensured by setting an explosion-proof specification for equipment, equipment, and equipment. As a result, the cost of the equipment becomes high. Further, even when the film is formed by sputtering gas containing hydrogen gas in the chamber, silicon atoms in the surface layer portion of the silicon film formed on the substrate are easily hydrogen-terminated, but hydrogen atoms are difficult to reach to the inside of the silicon film. Silicon atoms tend to remain unbonded. That is, it is difficult to efficiently hydrogen-terminate the entire silicon film including the inside.

The present invention has been proposed in order to solve the above problems, and an object of the present invention is to provide a film forming apparatus and a film forming method capable of efficiently forming a silicon hydride film at low cost.

In order to achieve the above object, a film forming apparatus according to the present invention includes a conveying unit having a rotary table for circulating and conveying a workpiece, a target made of a silicon material, and a sputtering gas introduced between the target and the rotary table into plasma. a film forming processing unit having a plasma generator to convert the film into a film and forming a silicon film on the work by sputtering; A process gas introduction unit for introducing a process gas containing hydrogen gas, and a plasma generator for converting the process gas into plasma, a hydrogenation processing unit for hydrogenating the silicon film formed on the work, wherein the conveying unit comprises: It conveys so that the said film-forming process part and the said hydrogenation process part may pass alternately.

Further, in the film forming method according to the present invention, a circulating transport step in which a transport unit having a rotary table circulates and transports a work, a target made of a silicon material, and a sputtering gas introduced between the target and the rotary table into plasma Hydrogenation having a film forming process for forming a silicon film on the work by sputtering, a process gas introducing unit for introducing a process gas containing hydrogen gas, and a plasma generator for converting the process gas into plasma. The processing unit includes a hydrogenation step of hydrogenating the silicon film formed on the work, and the conveying unit conveys the work so that the work passes through the film forming unit and the hydrogenation unit alternately.

According to the present invention, a silicon hydride film can be efficiently formed at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective plan view which shows typically the structure of the film-forming apparatus which concerns on this embodiment.
FIG. 2 is a cross-sectional view taken along line AA of FIG. 1 , and is a detailed view of an internal configuration of the film forming apparatus of the embodiment shown in FIG. 1 as seen from the side.
3 is a flowchart of processing by the film forming apparatus according to the present embodiment.
4 is a schematic diagram showing a processing process of a workpiece by the film forming apparatus according to the present embodiment.
5 is a graph showing a relationship between an extinction coefficient and a wavelength of a silicon film.

EMBODIMENT OF THE INVENTION Embodiment of the film-forming apparatus which concerns on this invention is described in detail, referring drawings.

[summary]

The film forming apparatus 100 shown in FIG. 1 is an apparatus for forming a silicon hydride film on the work 10 by sputtering. The work 10 is a light-transmitting substrate such as quartz or glass, and the film forming apparatus 100 forms a hydrogen-terminated silicon (Si-H) film on the surface of the work 10 . Further, the silicon film to be formed is an amorphous, that is, an amorphous silicon film, and silicon atoms constituting the film have unbonded hands. In addition, in this specification, "hydrogenation" and "hydrogen termination" have the same meaning. For this reason, in the following description, the hydrogenation process means the process which makes hydrogen termination.

The film forming apparatus 100 includes a chamber 20 , a transfer unit 30 , a film forming unit 40 , a hydroprocessing unit 50 , a load lock unit 60 , and a control device 70 . The chamber 20 is a container capable of evacuating the inside. The chamber 20 has a cylindrical shape, and its interior is partitioned by a partition 22, and is divided into a plurality of partitions in a sectoral shape. A film formation processing unit 40 is arranged in one of the compartments, a hydroprocessing unit 50 is arranged in another one of the compartments, and a load lock unit 60 is arranged in another one of the compartments. That is, in the chamber 20 , the film formation processing unit 40 , the hydrogenation processing unit 50 , and the load lock unit 60 are arranged in respective compartments.

The film-forming process part 40 and the hydrogenation process part 50 are arrange|positioned one by one. The work 10 goes around the inside of the chamber 20 several times in the circumferential direction to alternately pass through the film forming unit 40 and the hydrogenation unit 50 , thereby forming a silicon film on the work 10 . and hydrogenation of the silicon film are alternately repeated to grow a silicon hydride film of a desired thickness. In addition, in the case of increasing the hydrogen concentration, two or more hydrogenation processing units 50 may be disposed with respect to the film forming processing unit 40 . That is, you may arrange|position the hydroprocessing part 50 in two or more divisions. Even if two or more hydroprocessing units 50 are disposed, film formation → hydrogenation treatment → hydrogenation treatment → film formation… As described above, between the hydrogenation treatment and the film forming treatment, if no treatment other than the film forming treatment or the hydrogenation treatment is included, it is included in the aspect of “passing the film forming unit and the hydroprocessing unit alternately”.

As shown in FIG. 2, the chamber 20 is surrounded by the disk-shaped ceiling 20a, the disk-shaped inner bottom surface 20b, and the annular inner peripheral surface 20c, and is formed. The partition part 22 is a rectangular wallboard radially arrange|positioned from the center of a column shape, and extends from the ceiling 20a toward the inner bottom surface 20b, and does not reach the inner bottom surface 20b. That is, a cylindrical space is secured on the inner bottom surface 20b side.

In this columnar space, the rotary table 31 which conveys the workpiece|work 10 is arrange|positioned. The lower end of the partition part 22 faces the placement surface of the workpiece 10 in the rotary table 31 with a gap through which the workpiece 10 loaded on the conveyance part 30 passes. The dividing unit 22 divides the processing spaces 41 and 59 in which the workpiece 10 is processed in the film forming unit 40 and the hydroprocessing unit 50 . That is, the film formation processing unit 40 and the hydrogenation processing unit 50 are smaller than the chamber 20 , respectively, and have processing spaces 41 and 59 spaced apart from each other. Thereby, it is possible to suppress diffusion of the sputtering gas G1 of the film forming unit 40 and the process gas G2 of the hydrogenation processing unit 50 into the chamber 20 .

In addition, although plasma is generated in the processing spaces 41 and 59 in the film forming processing unit 40 and the hydrogenation processing unit 50 , as will be described later, the pressure in the processing space partitioned by a space smaller than the chamber 20 . can be adjusted, pressure can be easily adjusted, and plasma discharge can be stabilized. Therefore, as long as the above-described effect is obtained, if there are at least two partitions 22 that sandwich the film-forming processing unit 40 and two partitions 22 that sandwich the hydroprocessing unit 50 in plan view, good night.

In addition, the chamber 20 is provided with an exhaust port 21 . An exhaust part 80 is connected to the exhaust port 21 . The exhaust part 80 has piping, a pump, a valve, etc. which are not shown in figure. The inside of the chamber 20 can be pressure-reduced by the exhaust by the exhaust part 80 through the exhaust port 21, and it can be made into a vacuum.

The conveyance part 30 has the rotary table 31, the motor 32, and the holding|maintenance part 33, and circulates and conveys the workpiece|work 10 along the conveyance path|route L which is the locus|trajectory of a circumference. The rotary table 31 has a disk shape, and is widened so as not to come into contact with the inner circumferential surface 20c. The motor 32 continuously rotates at a predetermined rotation speed with the rotational center of the rotary table 31 as a rotation axis. The holding part 33 is a groove, a hole, a projection, a jig, a holder, etc. which are arranged in a circumferentially uniform arrangement on the upper surface of the rotary table 31, and the tray 34 on which the workpiece 10 is loaded is attached to a mechanical chuck or an adhesive chuck. maintained by The work 10 is arranged, for example, in a matrix form on the tray 34 , and six holding portions 33 are arranged at intervals of 60° on the rotary table 31 . That is, since the film forming apparatus 100 can collectively form a film on the plurality of workpieces 10 held by the plurality of holding units 33 , the productivity is very high.

The film formation processing unit 40 generates plasma to expose the target 42 made of a silicon material to the plasma. Thereby, the film-forming processing part 40 deposits the silicon particle pushed out by making the ions contained in plasma collide with the silicon material, and performs film-forming. As shown in FIG. 2 , this film-forming processing unit 40 is composed of a sputter source composed of a target 42 , a backing plate 43 , and an electrode 44 , a power supply unit 46 , and a sputtering gas introduction unit 49 . A plasma generator is provided.

The target 42 is a plate-shaped member made of a film-forming material that is deposited on the work 10 to form a film. The film forming material of this embodiment is a silicon material, and the target 42 serves as a supply source of silicon particles to be deposited on the work 10 . That is, the target 42 is made of a silicon material. As long as the "target comprised of a silicon material" is a sputtering target which can supply a silicon particle, even if it contains other than silicon|silicone, such as a silicon alloy target, it is permissible.

The target 42 is spaced apart from the conveyance path L of the work 10 arrange|positioned on the rotary table 31, and is provided. The target 42 is held on the ceiling 20a of the chamber 20 so that its surface faces the work 10 disposed on the rotary table 31 . Three targets 42 are provided, for example. The three targets 42 are provided in the position arranged on the vertex of a triangle in planar view.

The backing plate 43 is a support member for holding the target 42 . This backing plate 43 holds each target 42 individually. The electrode 44 is a conductive member for individually applying electric power to each target 42 from the outside of the chamber 20 , and is electrically connected to the target 42 . The electric power applied to each target 42 can be changed individually. In addition, a magnet, a cooling mechanism, etc. are suitably equipped with the sputtering source as needed.

The power supply unit 46 is, for example, a DC power supply for applying a high voltage, and is electrically connected to the electrode 44 . The power supply unit 46 applies electric power to the target 42 through the electrode 44 . Further, the rotary table 31 is at the same potential as the grounded chamber 20 , and by applying a high voltage to the target 42 side, a potential difference is generated. The power supply unit 46 may be an RF power supply for performing high-frequency sputtering.

The sputtering gas introduction unit 49 introduces the sputtering gas G1 into the chamber 20 as shown in FIG. 2 . The sputtering gas introduction unit 49 includes a supply source 90 of the sputtering gas G1 , a pipe 48 , and a gas introduction port 47 . The pipe 48 is connected to the supply source 90 of the sputtering gas G1, passes through the chamber 20 airtightly, extends inside the chamber 20, and its end is opened as a gas inlet 47, have.

The gas inlet 47 is opened between the rotary table 31 and the target 42 , and a sputtering gas G1 for film formation is formed in the processing space 41 formed between the rotary table 31 and the target 42 . to introduce As the sputtering gas G1, a rare gas can be employed, and argon (Ar) gas or the like is suitable. In addition, hydrogen gas is added to the sputtering gas G1 of this embodiment. The hydrogen concentration in the sputtering gas G1 is, for example, a low concentration of 3% or less. In addition, the hydrogen concentration in the sputtering gas G1 is the ratio (weight percent) of hydrogen gas in the sputtering gas G1 (rare gas + hydrogen gas).

The supply source 90 of the sputtering gas G1 supplies the sputtering gas G1 into the chamber 20 by controlling the introduction partial pressures of the rare gas and the hydrogen gas in the sputtering gas G1. Specifically, the supply source 90 includes a rare gas supply unit 91 , a hydrogen gas supply unit 92 , and a mixer 93A for mixing the rare gas and hydrogen gas. The rare gas supply unit 91 includes a cylinder 910 containing the rare gas, a pipe 911A for introducing the rare gas, and a mass flow controller (MFC: mass flow controller) 912A for adjusting the flow rate of the rare gas. The hydrogen gas supply unit 92 includes a cylinder 920 containing hydrogen gas, a pipe 921A for introducing hydrogen gas, and a flow control system (MFC) 922A for adjusting the flow rate of the hydrogen gas. The mixer 93A mixes hydrogen gas with the noble gas adjusted to a predetermined flow rate by the flow rate controllers 912A and 922A. The mixed gas of the rare gas and hydrogen gas mixed in the mixer 93A is supplied to the inside of the chamber 20 from the gas inlet 47 as sputtering gas G1.

In such a film formation processing unit 40, when sputtering gas G1 is introduced from the sputtering gas introduction unit 49, and the power supply unit 46 applies a high voltage to the target 42 through the electrode 44, the rotary table 31 The sputtering gas G1 introduced into the processing space 41 formed between the target 42 and the target 42 is converted into plasma, and active species such as ions are generated. Ions in the plasma collide with a target 42 made of a silicon material and push the silicon particles away.

Further, the work 10 circulated and conveyed by the rotary table 31 passes through the processing space 41 . The pushed out silicon particles are deposited on the work 10 when the work 10 passes through the processing space 41 , and a thin film of silicon film is formed on the work 10 . The work 10 is circulated and conveyed by the rotary table 31 , and the film forming process is performed by repeatedly passing through this processing space 41 .

The thickness of the silicon film depends on the amount of hydrogenation within a certain period of time of the hydrogenation processing unit 50, that is, the hydrogenation rate, but may be, for example, a thickness of about 1 to 2 atomic levels (0.5 nm or less). That is, whenever the workpiece 10 passes through the processing space 41 , silicon particles are stacked at a film thickness of one or two atomic levels to form a silicon film. As described above, most of the silicon atoms forming the silicon film have unbonded hands and are in an unstable state in which unpaired electrons exist. However, chemical species (atoms/molecules, ions, radicals, excited atoms/molecules, etc.) are generated when the hydrogen gas contained in the sputtering gas G1 becomes plasma. Hydrogen atoms contained in this chemical species bond to unbonded hands of some silicon atoms (hydrogen termination). However, since the hydrogen gas contained in the sputtering gas G1 has a low concentration, the amount of chemical species generated is relatively small, and the silicon atoms moving from the plasma to the work 10 are in intense motion, Efficiency is low.

The hydroprocessing unit 50 generates an inductively coupled plasma in the processing space 59 into which the process gas G2 containing hydrogen gas is introduced. That is, the hydrogenation processing unit 50 converts hydrogen gas into plasma to generate chemical species. Hydrogen atoms contained in the generated chemical species collide with the silicon film formed on the work 10 by the film formation processing unit 40 to bond with the silicon atoms. Thereby, the hydrogenation processing unit 50 forms a silicon hydride film which is a compound film. As described above, the hydrogenation processing unit 50 is a plasma processing unit that hydrogen-terminates silicon atoms of the silicon film on the work 10 using plasma. As shown in FIG. 2 , the hydroprocessing unit 50 includes a cylindrical body 51 , a window member 52 , an antenna 53 , an RF power source 54 , a matching box 55 , and a process gas introduction unit 58 . has a plasma generator constituted by

The cylindrical body 51 is a member covering the periphery of the processing space 59 . The cylindrical body 51 is a rectangular cylinder in which the horizontal cross section was rounded, as shown in FIG. 2, and has an opening. The cylindrical body 51 is fitted in the ceiling 20a of the chamber 20 and protrudes into the internal space of the chamber 20 so that the opening may face the turn table 31 side apart. The cylindrical body 51 is made of the same material as the rotary table 31 . The window member 52 is a flat plate of dielectric material such as quartz having a substantially similar shape to the horizontal cross section of the cylindrical body 51 . The window member 52 is provided to block the opening of the cylindrical body 51 , and is formed between the processing space 59 into which the process gas G2 containing hydrogen gas in the chamber 20 is introduced and the cylindrical body 51 . divide the interior.

The processing space 59 is formed between the rotary table 31 and the inside of the cylindrical body 51 in the hydroprocessing unit 50 . The hydrogenation process is performed by repeatedly passing the workpiece 10 circulated and conveyed by the rotary table 31 through the processing space 59 . Further, the window member 52 may be a dielectric such as alumina or a semiconductor such as silicon.

The antenna 53 is a conductor wound in a coil shape, and is disposed in the inner space of the cylindrical body 51 spaced apart from the processing space 59 in the chamber 20 by the window member 52 so that an alternating current By allowing it to flow, an electric field is generated. The antenna 53 is preferably disposed in the vicinity of the window member 52 so that the electric field generated from the antenna 53 is efficiently introduced into the processing space 59 through the window member 52 . An RF power supply 54 for applying a high-frequency voltage is connected to the antenna 53 . A matching box 55 serving as a matching circuit is connected in series to the output side of the RF power source 54 . The matching box 55 stabilizes the plasma discharge by matching the impedances of the input side and the output side.

The process gas introduction unit 58 introduces a process gas G2 containing hydrogen gas into the processing space 59 as shown in FIG. 2 . The process gas introduction unit 58 includes a supply source 90 of the process gas G2 , a pipe 57 , and a gas introduction port 56 . The pipe 57 is connected to the supply source 90 of the process gas G2, passes through the chamber 20 while hermetically sealing it, and extends into the chamber 20, and the end thereof is a gas inlet port 56 . is opened as

The gas introduction port 56 is opened in the processing space 59 between the window member 52 and the rotary table 31 to introduce the process gas G2. As the process gas G2, a rare gas can be employed, and argon gas or the like is suitable. In addition, hydrogen gas is added to the process gas G2 of this embodiment. The hydrogen concentration in the process gas G2 is, for example, a low concentration of 3% or less. That is, as the process gas G2, a gas common to the sputtering gas G1 can be used. In addition, the hydrogen concentration in the process gas G2 is the ratio (weight percent) of hydrogen gas in the process gas G2 (rare gas + hydrogen gas).

The supply source 90 of the process gas G2 supplies the process gas G2 to the process space 59 by controlling the introduction partial pressures of the rare gas and the hydrogen gas in the process gas G2 . Specifically, the supply source 90 includes a rare gas supply unit 91 , a hydrogen gas supply unit 92 , and a mixer 93B for mixing the rare gas and hydrogen gas. The rare gas supply unit 91 is provided with a cylinder 910 containing the rare gas, a pipe 911B for introducing the rare gas, and a flow rate control system (MFC) 912B for adjusting the flow rate of the rare gas. The hydrogen gas supply unit 92 includes a cylinder 920 containing hydrogen gas, a pipe 921B for introducing hydrogen gas, and a flow control system (MFC) 922B for adjusting the flow rate of the hydrogen gas. The cylinders 910 and 920 are shared with the supply source 90 of the sputtering gas G1. The mixer 93B mixes hydrogen gas with the noble gas adjusted to a predetermined flow rate by the flow rate controllers 912B and 922B. A mixed gas of the rare gas and hydrogen gas mixed in the mixer 93B is supplied into the processing space 59 from the gas inlet 56 as the process gas G2 .

In this hydrogenation processing unit 50 , a high-frequency voltage is applied from the RF power supply 54 to the antenna 53 . Thereby, a high-frequency current flows through the antenna 53, and an electric field by electromagnetic induction is generated. An electric field is generated in the processing space 59 through the window member 52 , and an inductively coupled plasma is generated in the process gas G2 . At this time, chemical species of hydrogen including hydrogen atoms are generated and collide with the silicon film on the work 10 , so that the hydrogen atoms bond with unbonded bonds of the silicon atoms. As a result, the silicon film on the work 10 is hydrogen-terminated, and a silicon hydride film stable as a compound film is formed. Here, since silicon atoms deposited on the work 10 remain on the work 10 without random violent movement, even if hydrogen in the process gas G2 has a low concentration, it is easy to bond to unbonded hands, Efficient hydrogen termination is possible.

The load lock unit 60 carries the tray 34 on which the unprocessed workpiece 10 is mounted from the outside into the chamber 20 by a conveying means (not shown) while maintaining the vacuum of the chamber 20 . And, it is an apparatus for carrying out the tray 34 on which the processed workpiece 10 is mounted to the outside of the chamber 20 . Since the load lock unit 60 having a well-known structure can be applied, its description is omitted.

The control device 70 includes an exhaust unit 80 , a sputter gas introduction unit 49 , a process gas introduction unit 58 , a power supply unit 46 , an RF power supply 54 , a conveyance unit 30 , and the like, the film forming apparatus 100 . Controls various elements that make up This control device 70 is a processing device including a programmable logic controller (PLC) and a central processing unit (CPU), in which a program in which control contents are described is stored. Specifically, the controlled contents include the initial exhaust pressure of the film forming apparatus 100, the power applied to the target 42 and the antenna 53, the flow rates of the sputtering gas G1 and the process gas G2, the introduction time and the exhaust time, The film-forming time, the rotation speed of the motor 32, etc. are mentioned. In addition, the control device 70 can respond to various types of film-forming specifications.

[movement]

Next, the overall operation of the film forming apparatus 100 controlled by the control apparatus 70 will be described. Moreover, the film-forming method which performs film-forming by the film-forming apparatus 100 in the order shown below, and the control method of the film-forming apparatus 100 are also one aspect|mode of this invention. 3 is a flowchart of processing by the film forming apparatus 100 according to the present embodiment. First, the tray 34 on which the workpiece 10 is mounted is sequentially loaded into the chamber 20 from the load lock unit 60 by the conveying means (step S01). In step S01, the rotary table 31 moves the empty holding part 33 to the carrying-in site|part from the load-lock part 60 sequentially. The holding unit 33 holds the trays 34 carried in by the conveying means individually, respectively. In this way, all the trays 34 on which the workpiece 10 on which the silicon hydride film is formed are mounted are arranged on the rotary table 31 .

The inside of the chamber 20 is exhausted from the exhaust port 21 by the exhaust part 80 and the pressure is always reduced. When the inside of the chamber 20 is decompressed to a predetermined pressure (step S02), the rotary table 31 on which the workpiece 10 is loaded rotates to reach a predetermined rotational speed (step S03).

When the predetermined rotational speed is reached, first, a silicon film is formed on the work 10 in the film forming processing unit 40 (step S04). That is, the sputtering gas introduction unit 49 supplies the sputtering gas G1 through the gas introduction port 47 . The sputtering gas G1 is supplied around the target 42 made of a silicon material. The power supply unit 46 applies a voltage to the target 42 . Thereby, the sputtering gas G1 is made into plasma. Ions generated by the plasma collide with the target 42 and push out silicon particles.

On the unprocessed work 10 (FIG. 4(A)), a thin film 12 (FIG. 4(B)) in which silicon particles are deposited on the surface when passing through the film forming unit 40 is formed. In this embodiment, every time it passes through the film forming processing unit 40 once, it is possible to deposit at a film thickness of 0.5 nm or less, that is, at a level that can contain 1 to 2 silicon atoms. Further, when the sputtering gas G1 is converted into plasma, a chemical species of hydrogen is generated from the hydrogen gas in the sputtering gas G1, and hydrogen atoms contained therein bond with some unbonded bonds of silicon atoms, thereby causing hydrogen termination. However, hydrogen termination at the time of film formation remains in a small amount.

In this way, the workpiece 10 on which the thin film 12 is formed by passing through the film forming processing unit 40 by the rotation of the rotary table 31 passes through the hydrogenation processing unit 50, and in the process, silicon of the thin film 12 is passed through. The atoms are hydrogen terminated (step S05). That is, the process gas introduction unit 58 supplies the process gas G2 containing hydrogen gas through the gas introduction port 56 . The process gas G2 containing hydrogen gas is supplied to the processing space 59 sandwiched between the window member 52 and the rotary table 31 . The RF power source 54 applies a high frequency voltage to the antenna 53 . An electric field generated by the antenna 53 through which a high frequency current flows by application of the high frequency voltage is generated in the processing space 59 through the window member 52 . Then, by this electric field, the process gas G2 containing the hydrogen gas supplied to the space is excited to generate plasma. In addition, hydrogen atoms contained in the chemical species of hydrogen generated by the plasma collide with the thin film 12 on the work 10 , thereby bonding with unbonded loss of silicon atoms, and the thin film 12 is formed into the silicon hydride film 11 . converted [Fig. 4(C)].

As described above, in steps S04 and S05 , the film forming process is performed by the workpiece 10 passing through the process space 41 of the moving film forming processing unit 40 , and the processing space 59 of the operating hydroprocessing unit 50 . ) through which the work 10 is subjected to hydrogenation treatment. In addition, it is assumed that "operating" has the same meaning as the plasma generating operation for generating plasma in the processing spaces 41 and 59 of each processing unit.

The operation of the hydrogenation processing unit 50, in other words, the plasma generation operation (introduction of the process gas G2 by the process gas introduction unit 58 and the application of a voltage to the antenna 53 by the RF power supply 54) is performed by the film formation processing unit ( What is necessary is just to start during the time until the workpiece|work 10 on which the film-forming was initially performed in 40) reaches|attains the hydroprocessing part 50. As shown in FIG. If there is no problem even if the surface of the work 10 before film formation is subjected to a hydrogenation treatment, the operation of the film formation processing unit 40, in other words, the plasma generation operation of the film formation processing unit 40 (sputter gas by the sputter gas introduction unit 49 ) (Introduction of G1 and voltage application to the target 42 by the power supply unit 46] and the plasma generation operation of the hydrogenation processing unit 50 may be started simultaneously, or before the plasma generation operation of the film formation processing unit 40 starts. The plasma generation operation of the hydrogenation processing unit 50 may be started.

The rotary table 31 rotates until the silicon hydride film 11 of a predetermined thickness is formed on the work 10, that is, until a predetermined time obtained in advance by simulation or experiment or the like has elapsed (step S06 'NO') '), continue rotating. In other words, during the time until the silicon hydride film 11 of a predetermined thickness is formed into a film, the work 10 circulates through the film forming unit 40 and the hydroprocessing unit 50 and continues to pass through the work 10 on the work 10 . The film forming process (step S04) of depositing silicon particles on the surface and the hydrogenation process of the deposited silicon particles (step S05) are alternately repeated (Fig. 4(D) to (I)).

If the predetermined time has elapsed (YES in step S06), first, the operation of the film forming processing unit 40 is stopped (step S07). Specifically, the introduction of the sputtering gas G1 by the sputtering gas introduction unit 49 is stopped, and the voltage application by the power supply unit 46 to the target 42 is stopped. Next, the operation of the hydroprocessing unit 50 is stopped (step S08). Specifically, the introduction of the process gas G2 by the process gas introduction unit 58 is stopped, and the supply of the high frequency power to the antenna 53 by the RF power source 54 is stopped. Then, the rotation of the rotary table 31 is stopped, and the tray 34 on which the work 10 is loaded is discharged from the load lock unit 60 (step S09).

In steps S07 and S08, the film forming processing unit 40 and the hydrogenation processing unit 50 are stopped, and a series of film forming processes are ended.

After the film-forming process is performed, each element of the film-forming process part 40, the hydrogenation process part 50, and the conveyance part 30 is controlled so that a series of film-forming processes are not completed without a hydrogenation process being performed. In other words, each element is controlled so that, among the film forming process and the hydrogenation process, the hydrogenation process is performed last to complete a series of silicon hydride film forming processes. In the present embodiment, during the time until the workpiece 10 that has passed through the film forming unit 40 passes through the hydroprocessing unit 50 and reaches the film forming unit 40 again, the film forming unit 40 is moved and changed. In other words, the plasma generation operation (introduction of the sputtering gas G1 by the sputtering gas introduction part 49 and the voltage application to the target 42 by the power supply part 46) in the film forming processing unit 40 is stopped.

Thus, in the film-forming apparatus 100, the workpiece|work 10 is conveyed alternately to the film-forming processing part 40 and the hydrogenation processing part 50, and also alternating conveyance is repeated several times. Thereby, the film forming process and the hydrogenation process are alternately performed a plurality of times. As shown in FIG. 4 , in the film forming process, a silicon material is sputtered and a thin film 12 of silicon in which the extruded silicon particles are deposited is formed on the work 10 . In the hydrogenation treatment, a process gas G2 containing hydrogen is plasmaized to generate a chemical species containing an atom of hydrogen, and the thin film 12 on the work 10 is exposed to the chemical species to form the thin film 12 . The silicon hydride film 11 is produced by hydrogenating each time it is formed.

By alternately performing the film forming treatment and the hydrogenation treatment a plurality of times, the film forming treatment and the hydrogenation treatment are alternately repeated, and the thin film 12 formed by depositing silicon particles is hydrogenated to form a silicon hydride film 11, and a silicon hydride film (11) The newly formed thin film 12 of silicon is hydrogenated by further depositing silicon particles thereon. By this series of silicon hydride film forming processes, a hydrogenated silicon hydride film 11 uniformly in the thickness direction is formed on the work 10 .

[action effect]

(1) As mentioned above, the film-forming apparatus 100 which concerns on this embodiment has the conveyance part 30 which has the rotation table 31 which circulates conveys the workpiece|work 10, and the target 42 comprised from a silicon material. and a film forming processing unit 40 having a plasma generator that converts the sputtering gas G1 introduced between the target 42 and the rotary table 31 into a plasma, and forming a silicon film on the work 10 by sputtering; A hydrogenation unit 50 having a process gas introduction unit 58 for introducing a process gas G2 containing hydrogen gas, and a plasma generator for converting the process gas G2 into plasma, and hydrogenating a silicon film formed on the work 10 . ), and the conveying unit 30 conveys the work 10 so that the work 10 alternately passes through the film forming unit 40 and the hydroprocessing unit 50 .

Moreover, in the film-forming method which concerns on this embodiment, the circulation conveyance process in which the conveyance part 30 which has the rotation table 31 circulates conveys the workpiece|work 10, the target 42 comprised from a silicon material, and a target A film forming process of forming a silicon film on the work 10 by sputtering by a film forming processing unit 40 having a plasma generator for converting the sputtering gas G1 introduced between the 42 and the rotary table 31 into a plasma; A hydrogenation processing unit 50 having a process gas introduction unit 58 for introducing a process gas G2 containing a gas and a plasma generator for converting the process gas G2 into plasma is configured to hydrogenate the silicon film formed on the workpiece 10 . and the hydrogenation process to be carried out, and the conveying unit 30 conveys the work 10 so that the work 10 passes through the film forming unit 40 and the hydroprocessing unit 50 alternately.

For this reason, film-forming and hydrogenation by sputtering can be repeated by passing the film-forming process part 40 and the hydrogenation process part 50 alternately while circulating and conveying the workpiece|work 10 by the rotary table 31. As shown in FIG. That is, by exposing the silicon atoms deposited by sputtering in the film formation processing unit 40 to the process gas G2 plasmaized by the hydrogenation processing unit 50, hydrogen can be efficiently bonded to the unbonded hands of the silicon atoms. Therefore, the ratio of hydrogen-terminated silicon atoms in the film can be easily increased. Therefore, the silicon hydride film can be efficiently formed without increasing the hydrogen concentration of the process gas G2.

When forming a film by sputtering in a state in which the workpiece 10 is stopped in the chamber, the film formation tends to proceed and the film thickness tends to grow. When the film thickness is increased, even when exposed to the process gas G2 containing plasmaized hydrogen gas, the surface layer is hydrogen-terminated, but hydrogen atoms are difficult to reach to the inside of the film, and silicon atoms remaining unbonded in the film will remain In this embodiment, while the work 10 is circulated and conveyed, the film formation processing unit 40 and the hydrogenation processing unit 50 are passed alternately to expose the silicon atoms deposited by sputtering to the process gas G2, so that the thin film is formed. The film is formed, the surface layer is hydrogen-terminated in a thin film thickness, and by repeating this, the silicon atoms present in the finally formed film are in the hydrogen-terminated state. Therefore, since hydrogen termination can be uniformly carried out in the thickness direction of the silicon film, the uniformity of hydrogen termination of the entire silicon film can be improved.

In addition, as described above, when film formation and hydrogen termination of the workpiece 10 are performed in a common chamber, in order to reduce unbonded loss, it is necessary to set the hydrogen concentration in the sputtering gas to 10% or more. However, since there is a limit to the bonding ratio between unbonded hands and hydrogen atoms, increasing the hydrogen concentration in the gas increases the number of hydrogen atoms that do not bond with silicon atoms, and the amount of hydrogen atoms present in the film becomes non-uniform, which deteriorates the properties of the film. . In order to cope with this, a treatment for releasing hydrogen atoms is required. As a result of earnest examination, the inventor of the present invention conducts sputtering by alternately passing the film forming unit 40 and the hydroprocessing unit 50 while circulating and conveying the work 10 by the rotary table 31 against such a technical common knowledge. It was found that, by repeating film formation and hydrogenation by ? For this reason, in this embodiment, the residual of the hydrogen atom which does not couple|bond with the silicon atom which generate|occur|produces abundantly by raising a hydrogen concentration can also be reduced, and there is no need to release a hydrogen atom.

(2) The film forming processing unit 40 has a sputtering gas introduction unit 49 that introduces a sputtering gas G1 containing hydrogen gas. For this reason, even during film formation, the sputtering gas G1 containing hydrogen gas is converted into plasma, and the generated hydrogen chemical species can be bonded to unbonded hands of silicon atoms. As described above, hydrogen termination alone during film formation is insufficient for hydrogen termination, but in combination with hydrogenation in the hydrogenation unit 50, hydrogen termination of silicon atoms constituting the film can be improved.

(3) The sputtering gas introduction unit 49 introduces the process gas G2 and the common sputtering gas G1. By using a common gas, a gas source, such as a cylinder, can be commonized in the film-forming process part 40 and the hydrogenation process part 50, and cost can be reduced.

(4) The hydrogen concentration in the process gas G2 is 3% or less. Since the hydrogen gas concentration in which an explosion risk arises is generally about 4 %, by setting it as 3 % or less which is the range which can be safely used, the possibility that an explosion will occur can be reduced significantly. For this reason, the explosion-proof specification of an installation becomes unnecessary, and cost can be reduced significantly.

(5) The film thickness of the silicon film formed each time it passes through the film-forming process part 40 is 0.5 nm or less. For this reason, not only the surface of the silicon film but also silicon atoms present in the film are hydrogen-terminated by laminating silicon to a film thickness of 1 to 2 atomic level and hydrogenating it to a film thickness of 1 to 2 atomic level, thereby increasing the thickness of the inside. Hydrogen termination can be uniformly in the direction.

(6) The film-forming apparatus 100 is provided with the chamber 20 in which the film-forming process part 40 and the hydroprocessing part 50 are arrange|positioned in each compartment, The film-forming process part 40 and the hydroprocessing part 50 rotate It is provided on the conveyance path|route L of the circumference|surroundings of the table 31. Thereby, only by continuously moving the work 10 in one direction, alternate conveyance to the film-forming processing unit 40 and the hydroprocessing unit 50 arranged on the circumferential conveyance path L of the rotary table 31 is possible. Thus, the film forming process and the hydrogenation process can be alternately and repeatedly performed. For this reason, switching between a film-forming process and a hydrogenation process can be performed easily, and it becomes easy to balance adjustment of a film-forming process time and a hydrogenation process time.

[Measurement of extinction coefficient]

In a film forming apparatus, an amorphous silicon film (α-Si film), that is, various silicon films including a silicon hydride film, formed by alternately passing a film forming unit and a hydrogenation unit while circulating and conveying a work by a rotary table (k) ) is shown in FIG. 5 . 5 is a plot of the extinction coefficient k in a film formed with the hydrogen concentrations in the sputtering gas G1 and the process gas G2 under the conditions 1 to 8 according to the observed wavelength (400 to 1200 nm); It is a graph. The extinction coefficient k is calculated from the reflectance and transmittance measured by making the inspection light incident on the work on which the silicon film is formed and receiving the emitted light. The extinction coefficient k is an integer indicating how much light the medium absorbs when light is incident on a certain medium. The larger the extinction coefficient k (as it is plotted in the upper part of FIG. 5), the higher the light absorptivity, and the smaller the extinction coefficient k is, the higher the light transmittance. By terminating the unbonded loss of the silicon film formed with hydrogen atoms, the extinction coefficient k tends to be small. For this reason, by measuring the extinction coefficient k, it can be grasped|ascertained whether hydrogen termination is performed favorably.

(Film formation conditions)

The film-forming conditions are as follows.

・Workpiece: glass substrate

・Target: Si

· Holder: SUS

・Distance between target and workpiece: 100 mm (face-to-face)

· Rotational speed of the rotary table: 60 rpm

・High frequency applied power to the antenna (hydrogenation processing unit): 2000 W

DC applied electric power to sputtering source: 1500-2500 W (value of electric power applied to each sputtering source in the film-forming processing unit provided with three sputtering sources)

・Film formation rate: 0.2 nm/s

· Overall film thickness: 300 nm

(gas condition)

The conditions of the sputtering gas G1 and the process gas G2 are as follows.

<Condition 1>

G1: Ar+H (0%) 50 sccm/G2: Ar+H (0%) 200 sccm

<Condition 2>

G1: Ar+H (0%) 50 sccm/G2: Ar+H (3%) 200 sccm

<Condition 3>

G1: Ar+H (0%) 50 sccm/G2: Ar+H (5%) 200 sccm

<Condition 4>

G1: Ar+H (0%) 50 sccm/G2: Ar+H (7%) 200 sccm

<Condition 5>

G1: Ar+H (0%) 50 sccm/G2: Ar+H (10%) 200 sccm

<Condition 6>

G1: Ar+H (3%) 50 sccm/G2: Ar+H (3%) 200 sccm

<Condition 7>

G1: Ar+H (5%) 50 sccm/G2: Ar+H (0%) 200 sccm

<Condition 8>

G1: Ar+H (7%) 50 sccm/G2: Ar+H (0%) 200 sccm

[result]

Condition 1 is a condition in which hydrogen gas is not added to either the sputtering gas G1 or the process gas G2. Conditions 7 and 8 are conditions in which hydrogen gas is added only to the sputtering gas G1. Condition 1, condition 7, and condition 8 had the same result (result 1).

Conditions 2 to 5 are conditions in which hydrogen gas is added to the process gas G2. In conditions 2-5, the fall of the extinction coefficient (k) was shown notably than condition 1. In particular, it was condition 5 that the extinction coefficient (k) was the smallest at a wavelength of 600 nm or more. However, as in condition 6, when 3% of hydrogen gas is introduced into the process gas G2 and the sputtering gas G1, respectively, 3% or more of hydrogen gas is introduced at a wavelength of about 1000 nm or more (infrared wavelength range). The extinction coefficient (k) was smaller than that of condition 2, condition 3, and condition 4 (result 2).

Even when hydrogen gas was added only to the sputtering gas G1 as in the conditions 7 and 8, it was found that the hydrogenation efficiency was poor as in the result 1. As in result 2, the reason that the extinction coefficient k became small in conditions 2-5 can be said to be because hydrogenation was performed favorably. And, as in condition 6, by adding hydrogen gas to each of the process gas G2 and the sputtering gas G1, it was found that hydrogenation can be efficiently performed without raising the hydrogen concentration to a concentration with an explosion risk.

As described above, by adding hydrogen gas to the process gas G2, a film having a small extinction coefficient k in the infrared wavelength range can be formed. Thereby, for example, it can be applied to optical products, such as an infrared sensor which absorbs light in a visible region, and transmits light in an infrared region.

[Other embodiment]

Although the embodiment of this invention and the modified example of each part were described, this embodiment and the modified example of each part are shown as an example, and are not intended to limit the scope of the invention. These novel embodiment mentioned above can be implemented in other various forms, and various abbreviation|omission, substitution, and change can be performed in the range which does not deviate from the summary of invention. These embodiments and their modifications are included in the scope and summary of the invention, and are included in the invention described in the claims.

For example, in the above aspect, the sputtering gas G1 and the process gas G2 are common, but the rare gas and hydrogen concentrations may be different. In addition, hydrogen gas may not be included in the sputtering gas G1 introduced by the sputtering gas introduction unit 49 . That is, the hydrogenation process may be performed only in the hydroprocessing unit 50 . In this case, the hydrogen concentration of the process gas G2 may be the same as described above, but in order to further increase the coupling efficiency, the hydrogen concentration may be set high enough to suppress the possibility of an explosion to a lower level. In addition, a plurality of hydrogenation processing units 50 may be provided to improve hydrogenation efficiency.

In addition, although the cylinders constituting the supply source 90 of the sputtering gas G1 and the process gas G2 are the cylinder 910 containing the rare gas and the cylinder 920 containing the hydrogen gas, it is not limited thereto. . For example, the cylinder constituting the supply source 90 may be a cylinder containing a mixed gas of hydrogen gas and rare gas mixed in a ratio determined in advance. In this case, the flow control systems 912A, 922A, 912B, and 922B and the mixers 93A and 93B for mixing the rare gas and hydrogen gas are omitted, and the mixed gas of a predetermined flow rate is supplied from the pipes 48 and 57 through the flow control system. introduced into the processing spaces 41 and 59 . In addition, as long as the hydrogen concentrations of the sputtering gas G1 and the process gas G2 may be the same, a common cylinder can be used.

Further, for example, in the above-described embodiment, after stopping the operation of the film-forming processing unit 40 in step S07, the operation of the hydroprocessing unit 50 is stopped in step S08, and the rotation of the rotary table 31 is stopped in step S09. Although it was stopped, it is not limited to this, The conveyance part 30 so that the conveyance of the workpiece|work 10 may be stopped by finally passing the hydroprocessing unit 50 in operation among the film forming unit 40 and the hydroprocessing unit 50 . ), the film formation processing unit 40 , and the hydrogenation processing unit 50 may be controlled. In this case, for example, after the rotation of the rotary table 31 is stopped so as to stop the conveyance of the work 10 by passing the hydroprocessing unit 50 last, the operation of the film forming unit 40 and the operation of the hydroprocessing unit 50 are performed. Operation may be stopped. In addition, for example, since the film formation processing is not performed in the film formation processing unit 40 that is not in operation, if the operation of the film formation processing unit 40 is stopped, the film formation processing unit 40 passes through the hydroprocessing unit 50 and then passes through the film formation processing unit 40 . You may stop conveyance of the workpiece|work 10.

In addition, for example, in the above-described embodiment, in order to stop the operation of the film formation processing unit 40 , that is, to stop the plasma generation operation, the voltage application by the power supply unit 46 together with the stop of the introduction of the sputtering gas G1 . has been stopped, but the present invention is not limited thereto, and the operation of at least any one of the introduction of the sputter gas G1 by the sputter gas introduction unit 49 or the voltage application by the power supply unit 46 may be stopped. Similarly, in order to stop the plasma generation operation when the hydrogenation processing unit 50 is stopped, at least one of the introduction of the process gas G2 and the voltage application by the RF power source 54 may be stopped.

In addition, in the case of laminating a multilayer film, a film forming processing unit and a plasma processing unit may be further provided in the chamber 20 . In this case, in addition to the film formation processing unit 40 , a film formation processing unit using a target material different from the film formation processing unit may be added, or a film formation processing unit using a target material of the same type may be added. In addition, a plasma processing unit using a process gas different from that of the hydrogenation processing unit 50 may be added.

10 work
11 Silicon hydride film
12 thin film
20 chamber
20a ceiling
20b inner bottom
If you give 20c
21 exhaust vents
22 compartment
30 Carrier
31 turn table
32 motor
33 maintenance
34 tray
40 film forming unit
41 processing space
42 target
43 backing plate
44 electrode
46 power supply
47 gas inlet
48 plumbing
49 sputter gas inlet
50 hydroprocessing unit
51 cylinder
52 window member
53 antenna
54 RF power
55 matching box
56 gas inlet
57 plumbing
58 Process gas inlet
59 processing space
60 load lock
70 control unit
80 exhaust
90 source
91 rare gas supply
92 hydrogen gas supply
93A, 93B Mixer
910, 920 bomb
911A, 911B, 921A, 921B piping
912A, 912B, 922A, 922B Flow Control Meters
100 film forming device
G1 sputter gas
G2 process gas

Claims (8)

A chamber which is a container capable of making the inside into a vacuum;
a conveying unit provided in the chamber and having a rotary table for circulating and conveying the work;
A silicon film is formed on the workpiece by sputtering, comprising: a target made of a silicon material; a sputtering gas introduction part for introducing a sputtering gas into a processing space between the target and the rotary table; and a plasma generator for converting the sputtering gas into plasma. a film forming processing unit to
a cylindrical body having one end of the opening facing the rotary table side; a process gas introduction section for introducing a process gas containing hydrogen gas into a processing space surrounded by the cylindrical body; and a plasma generator for turning the process gas into plasma; a hydrogenation processing unit for hydrogenating the silicon film formed on the work;
A partitioning unit in which the film-forming processing unit and the hydroprocessing unit are disposed in respective compartments, and partitioning between the processing space of the film-forming processing unit and the processing space of the hydroprocessing unit
to provide
The partition part is provided such that its lower end faces the rotary table with a gap through which the work mounted on the rotary table passes,
The conveying unit conveys the work so that it alternately passes through the film forming unit and the hydroprocessing unit,
The sputtering gas includes hydrogen gas. delete The film forming apparatus according to claim 1, wherein the sputtering gas introduction unit introduces a sputtering gas common to the process gas. The film forming apparatus according to claim 1 or 3, wherein the hydrogen concentration in the process gas is 3% or less. The film forming apparatus according to claim 1 or 3, wherein a film thickness of the silicon film formed each time it passes through the film forming unit is 0.5 nm or less. The film forming apparatus according to claim 1 or 3, wherein the film forming unit and the hydrogenation unit are provided on a conveyance path of the circumference of the rotary table. delete a circulation conveying step in which a conveying unit having a rotary table provided in a chamber that is a container capable of evacuating the inside, circulatingly conveys the work;
A film forming processing unit having a target made of a silicon material and a plasma generator that converts a sputtering gas containing hydrogen gas into a plasma, which is introduced into a processing space between the target and the rotary table, forms a silicon film on the work by sputtering. a film forming process,
A hydrogenation processing unit comprising: a process gas introduction unit for introducing a process gas containing hydrogen gas into a processing space surrounded by a cylindrical body having an opening at one end toward the rotary table; and a plasma generator for converting the process gas into plasma; Hydrogenation process of hydrogenating the silicon film formed on the
including,
A partitioning unit in which the film-forming processing unit and the hydroprocessing unit are disposed in respective compartments, and partitioning between the processing space of the film-forming processing unit and the processing space of the hydroprocessing unit
to provide
The partition part is provided such that its lower end faces the rotary table with a gap through which the work mounted on the rotary table passes,
The film forming method according to claim 1, wherein the conveying unit conveys the workpiece so that the work passes alternately through the film forming unit and the hydroprocessing unit.

Images