KR20230034251A - Film forming apparatus, method of forming film, and storage medium - Google Patents

Abstract

The present invention provides a high productivity technique in performing film formation on a semiconductor wafer, for instance, by alternately supplying source gas and reaction gas and sequentially stacking reaction products. Load stands (2) are arranged on a rotatable turntable (1) in a processing container (5) at equal intervals in the circumferential direction. An area above the turntable (1) is divided into four processing areas (S1 to S4) by separation parts (4) installed at equal intervals in the circumferential direction, and source gas is supplied to every other processing area (S1, S3). Additionally, reaction gas is supplied to the alternate processing areas (S2, S4) to generate plasma. Wafers (W) are loaded onto each load stand (2), and the turntable (1) is intermittently rotated to sequentially stop at each processing area (S1 to S4). When the wafers (W) are respectively positioned in the processing areas (S1 to S4), the load stands (2) are rotated to perform the ALD processing simultaneously on each wafer (W).

Description

Film formation apparatus, film formation method, and storage medium

The present invention relates to the technical field of performing a film formation process by alternately supplying a first gas and a second gas, which are process gases, to a substrate.

As one of the methods of forming a thin film such as a silicon nitride film on a semiconductor wafer (hereinafter referred to as "wafer"), a source gas for the thin film and a reactive gas reacting with the source gas are sequentially applied to the surface of the wafer. A so-called ALD (Atomic Layer Deposition) method in which a reaction product is deposited by supplying is known. As a film forming apparatus for performing a film forming process using this ALD method, as described in, for example, Patent Document 1, a rotary table for arranging and revolving a plurality of wafers in the circumferential direction is installed in a vacuum container, and , a structure in which a plurality of gas supply nozzles are provided so as to face the rotary table is exemplified. In this apparatus, a separation region to which separation gas is supplied is formed between processing regions to which processing gases are supplied, respectively, so that processing gases do not mix with each other. Further, a region for activating the reactive gas using plasma and a region for modifying the thin film using plasma are formed spaced apart in the circumferential direction.

The film formation apparatus is a so-called semi-batch method in which processing is performed by loading a plurality of substrates on a rotary table, and has advantages of good in-plane uniformity and improved throughput, but in the industry, such a method Further improvement in productivity in the apparatus is desired.

Patent Literature 2 describes a device in which four semiconductor targets are loaded and the upper region of a rotatable table is separated into four by partition walls, and it is described as "effective against magnetic saturation reactions such as ALD", The method of operation is unclear and does not imply the present invention.

Japanese Unexamined Patent Publication No. 2013-161874 Japanese Unexamined Patent Publication No. 2007-247066

The present invention was made under such circumstances, and its object is to provide a technique with high productivity in performing a film formation process by alternately supplying a first gas and a second gas to a substrate.

The present invention is a film forming apparatus for forming a thin film on a substrate by performing a plurality of cycles of alternately supplying a first gas and a second gas, which are processing gases, to a substrate in a processing container that creates a vacuum atmosphere, comprising:

n (n is an integer greater than or equal to 2) number of first processing regions formed at intervals along the circumferential direction of the processing container and supplying the first gas to process the substrate;

n second processing regions formed between the n first processing regions along the circumferential direction and supplying the second gas to process the substrate;

a separator configured to separate the n first processing regions from the n second processing regions;

Loading units configured to be able to revolve along the circumferential direction and disposed in plurality along the circumferential direction for loading substrates, respectively;

A control unit for intermittently revolving the loading part so that the substrate is alternately positioned in the n first processing regions and the n second processing regions in a state in which the revolving movement is stopped,

The loading unit is arranged so that the same number of substrates are positioned in each of the n first processing areas and the n second processing areas when the loading unit stops revolutionizing.

Another invention is a film formation method for forming a thin film on a substrate by alternately supplying a first gas and a second gas, which are processing gases, to the substrate in a processing container forming a vacuum atmosphere, the method comprising the steps of:

In the processing container, n (n is an integer of 2 or more) first processing regions are formed at intervals along the circumferential direction of the processing container, and separated between the n first processing regions along the circumferential direction. forming n second processing regions with the regions interposed therebetween;

It is configured to be able to revolve along the circumferential direction, and 2n × m pieces (m is an integer of 1 or more) are disposed along the circumferential direction, and a loading unit for loading each substrate is installed,

(1) a step of loading substrates on each loading unit;

(2) In a state in which the rotation of each loading unit is stopped so that substrates are located in each of the n first processing regions and the n second processing regions, the n first processing regions and the n second processing regions supplying the first gas and the second gas to regions, respectively;

a step of continuously revolving the stacking unit to position the substrates placed in each of the n first processing regions and the n second processing regions in adjacent processing regions;

Then, in a state in which revolution of the loading unit is stopped, supplying the first gas and the second gas to the n first processing regions and the n second processing regions, respectively;

A process of repeating a cycle including a plurality of times;

includes

Another invention is a film forming apparatus used in a film forming apparatus that forms a thin film on a substrate by performing a plurality of cycles of alternately supplying a first gas and a second gas, which are processing gases, to a substrate in a processing container that creates a vacuum atmosphere. As a storage medium storing a computer program,

The computer program has a group of steps configured to execute the film forming method.

When a substrate is loaded on a loading unit disposed in the processing container and film formation is performed by alternately supplying a first gas and a second gas as processing gases, the first processing region and the second processing are performed along the circumferential direction of the processing container. While forming an area through a separation part, a plurality of sets of first processing areas and second processing areas are provided. And, when the loading unit is stopped, the loading unit is set so that the same number of substrates are positioned in each of the first processing area and the second processing area, and the substrates are in a state in which revolution is stopped in the first processing area and the second processing area. The film formation process is performed by intermittently revolving the mounting unit so as to be positioned alternately at For this reason, since the process can be simultaneously performed at a plurality of locations by the first gas and the second gas when the loading unit stops revolutionizing, the productivity is high.

1 is a perspective view showing the outline structure of main parts of a film forming apparatus according to a first embodiment of the present invention.
2 is a longitudinal sectional view of the film forming apparatus according to the first embodiment of the present invention.
3 is a cross-sectional view of the film forming apparatus according to the first embodiment of the present invention.
FIG. 4 is a transverse cross-sectional view showing the overlapping plasma generating unit in FIG. 3 .
5 is a longitudinal cross-sectional view taken along a part of the radial direction of a rotary table used in the film forming apparatus.
6 is an explanatory diagram showing the operation of the film forming device.
7 is an explanatory diagram showing the operation of the film forming device.
8 is an explanatory diagram showing the operation of the film forming device.
9 is an explanatory diagram showing the operation of the film forming device.
10 is an explanatory diagram showing the operation of the film forming device.
11 is an explanatory diagram showing the operation of the film forming device.
12 is an explanatory diagram showing the operation of the film forming device.
13 is an explanatory diagram showing the operation of the film forming device.
14 is an explanatory diagram showing the operation of the film forming device.
15 is a plan view showing a modified example of the first embodiment of the present invention.
Fig. 16 is a perspective view schematically showing a rotating mechanism used in the second embodiment of the present invention.
Fig. 17 is an explanatory diagram showing an arrangement of magnetic poles of the rotation mechanism.
18 is a longitudinal sectional view of a film forming apparatus according to a second embodiment of the present invention.
Fig. 19 is a plan view showing the arrangement of wafers when the continuous rotation mode used in the third embodiment of the present invention is selected.
Fig. 20 is a plan view showing the arrangement of wafers when the intermittent rotation mode used in the third embodiment of the present invention is selected.
21 is a plan view showing a substrate processing system using a film forming apparatus according to a third embodiment of the present invention.

[Overview of Embodiments of the Invention]

An outline of an embodiment of the present invention will be described. The film forming apparatus used in this embodiment includes a rotary table made of, for example, quartz in a processing container that is a vacuum container, and FIG. 1 schematically shows the rotary table 1 and its surroundings. Four circular concave portions 11 are formed at equal intervals in the circumferential direction on the upper surface side of the rotary table 1, and in each concave portion 11, a loading table constituting a loading portion for loading wafers (substrates) ( 2) is placed. On the lower side of the rotary table 1, a rotary support 12 having an outer shape concentric with the rotary table 1 is provided, and the rotary table 1 is attached to the rotary support 12, not visible in FIG. It is supported through a support member that does not. The rotary support 12 is rotatable by a rotation shaft not shown in FIG. 1 , and the rotary table 1 rotates, for example, clockwise along with the rotation of the rotary support 12 .

The mounting table 2 is installed on the upper end of the rotating shaft 21 , and the rotating shaft 21 penetrates the central portion of the concave portion 11 and is rotatably supported by the rotary support 12 . A driven gear part 31 made of a magnet is installed at the lower end of the rotation shaft 21, and a driving gear part 32 made of a magnet for rotating the driven gear part 31 in a non-contact manner is installed on the processing container side of the rotary table ( It is installed corresponding to the stop position of 1), and rotation shaft 21 is rotated through driven gear unit 31 by rotation of drive gear unit 32, thereby rotating rotation of mounting table 2.

On the ceiling of the processing vessel, four separators 4 are installed so as to extend in the radial direction of the rotation table 1 so as to equally divide the area above the turn table 1 into four processing areas in the circumferential direction. The rotation table 1 rotates intermittently, and the four loading tables 2 are controlled so as to stop at the four treatment areas, respectively. For this reason, when wafers are loaded on each mounting table 2 and viewed in a plan view, a state shown in FIG. 6, which will be described later, is obtained.

So-called ALD is a process of stacking reaction products by sequentially supplying a raw material gas (adsorption gas) of a thin film and a reactive gas that reacts with the raw material gas to the surface of a wafer, and a cycle of supplying the raw material gas and the reactive gas in order is performed. It is a method of repeating multiple cycles. In the present embodiment, for example, a source gas supply region, a reaction gas supply region, a source gas supply region, and a reactive gas supply region are assigned to four processing regions when viewed clockwise, respectively. there is. Therefore, by intermittently rotating the turntable 1 so as to stop while the wafer is located in each processing area, two cycles can be performed while rotating the turntable 1 once.

In addition, in the stop position where the rotary table 1 is stopped to perform the film formation process on the wafer, rotation of the drive gear unit 32 causes the rotation shaft 21 to rotate as described above, so that the wafer rotates. That is, the wafer is subjected to film formation while being rotated.

[Details of Embodiments of the Invention]

(First Embodiment)

Next, details of the structure and operation of the film forming apparatus used in the first embodiment of the present invention will be described. FIG. 2 is a longitudinal sectional view of a film forming apparatus in which a section corresponding to a region for supplying a source gas is positioned on the right side, and a section corresponding to a region for supplying a reactive gas is positioned on the left side. The film forming apparatus includes a flat processing container 5, and the bottom of the processing container 5 is radially divided into a central portion 51 and an annular portion 52 surrounding the central portion 51. . The central portion 51 is supported by a post 53 protruding from above at the center of the ceiling of the processing container 5 , and the annular portion 52 is fixed to the side wall of the processing container 5 .

A heating unit 54 for heating the wafer W as a substrate is provided on the upper surface side of the central portion 51 and the annular portion 52, and the heating unit 54 is placed in a container made of quartz, for example. It consists of installing a heating wire. The power supply line 55 of the heating part 54 in the central portion 51 is led out through the inside of the support column 53 . Although not shown, the power supply line of the heating unit 54 in the annular portion 52 is led out through the inside of the processing container 5 .

On the lower side of the processing container 5 , the aforementioned rotation support 12 is disposed so as to be horizontally rotatable by the rotary shaft 13 installed at a position corresponding to the central portion of the processing container 5 . The rotating shaft 13 is rotationally driven by a driving unit housed in the case body 14 and not visible in the drawing.

A rotation table 1 is installed in the processing container 5 , and the rotation table 1 is supported by a rotation support body 12 via a rod-shaped support member 15 . The supporting members 15 are disposed across an annular gap 56 between the annular portion 52 and the central portion 51 which is the bottom of the processing chamber 5, and are provided in plurality along the circumferential direction. . In addition, the right side portion of the rotary table 2 in FIG. 2 indicates an area where the loading table 2 is not installed, and the left portion indicates a portion where the placing table 2 is installed.

As described above, four circular concave portions 11 are formed at regular intervals in the circumferential direction on the upper surface side of the rotary table 1, and the mounting platform 2 on which the wafer W is placed is placed in each concave portion. It is supported by the axis of rotation 21 so as to converge within (11). The mounting table 2 is set so that the top surface of the wafer W coincides with the height of the top surface of the turn table 1 when the wafer W is placed thereon. In FIGS. 3 and 4 , illustration of the concave portion 11 located around the mounting platform 2 is omitted. Each rotation shaft 21 passes through an annular gap 56 and is supported by the rotation support 12 by a bearing portion 22 so that rotation is possible.

Therefore, it can be said that the mounting platform 2 is configured to be able to rotate while being able to rotate. Each rotation shaft 21 extends to the lower side of the bearing part 22, and the driven gear part 31 already described is installed at the lower end. On the lower side of the bottom of the processing container 5, a cover 6 for partitioning the rotary support 12 and the like from the atmospheric atmosphere is provided. The cover body 6 is molded into a shape in which an annular concave portion 61 is formed by concave a portion close to the periphery of a flat cylindrical body, and the inner wall surface on the outer peripheral side of the concave portion 61 is flat. When viewed, drive gear parts 32 are installed at four places at equal intervals.

The drive gear part 32 is provided at the front end of a horizontal rotational shaft 33 penetrating the side wall of the concave portion 61 of the cover body 6, and on the proximal end of the rotational shaft 33, the rotational shaft 33 A drive unit 34 for rotating and moving in the axial direction is provided. N poles and S poles are alternately magnetized in the circumferential direction on the side circumferential surface of the driven gear unit 31, and N poles and S poles are alternately magnetized in the circumferential direction on one side of the drive gear unit 32. there is. The driven gear part 31 and the drive gear part 32 are positioned so that the passage area of the driven gear part 31 faces a site closer to the upper side than the center of one surface side of the drive gear part 32 .

The drive gear unit 32 is a driven gear unit when the wafer W is located at a position corresponding to the stop position of the rotary table 1, that is, at the center of the circumferential direction in each of the four processing regions described above. It is installed in the position where the magnetic gear is constituted between (31). The drive gear unit 32 is configured to rotate the shaft 33 so as to approach the driven gear unit 31 and form a self gear when the driven gear unit 31 stops at a position facing the drive gear unit 32. moves forward (moves toward the radial center side of the processing container 5). Then, by rotating the driving gear part 32 counterclockwise, for example, when viewed from the side of the rotational shaft 33, the driven gear part 31 rotates clockwise, thereby causing the mounting table 2 to rotate on its own. . Further, on the wall surface on the inner circumferential side of the concave portion 61 of the cover body 6, at a position facing the drive gear portion 32 with the passage region of the driven gear portion 31 interposed therebetween, for example, A brake member 35 made of a magnet body is installed. The brake member 35 serves to stop the rotation of the driven gear unit 31 after retracting the drive gear unit 32 and separating it from the driven gear unit 31 when the rotary table 1 is rotated. is to do

Among the previously described four processing regions, a region for supplying a source gas to be adsorbed onto the wafer (W) is a first processing region, and a region for supplying a reactive gas and reacting with the source gas on the wafer (W) is a second processing region. shall be called As described in the section of the summary of the embodiment, the first processing region and the second processing region are alternately formed along the circumferential direction of the processing container 5 .

In the first processing region located on the right side of the center of the processing container 5 in FIG. 2 , a source gas nozzle 71 , which is a source gas supply unit for supplying source gas, is higher than an access road of a conveyance mechanism CA, which will be described later. At this location, it passes through the side wall of the processing vessel 5 and is arranged parallel to the rotary table 1 . As shown in FIG. 3 , the source gas nozzle 71 extends along a line inclined in the transverse direction with respect to a line connecting a portion penetrating the sidewall of the processing container 5 and the center of the rotary table 1, there is. In addition, the source gas nozzle 71 has gas discharge holes 72 formed at intervals in the longitudinal direction on the lower surface side, and the arrangement area of the gas discharge holes 72 has a length covering the diameter of the wafer W. It is set.

The proximal end of the source gas nozzle 71 is connected to a source gas supply system 73 including a source gas supply source and a gas supply control device group. As an example, if the film formation process performed on the wafer W is a silicon nitride film, DCS (dichlorosilane) gas is used as the source gas, for example.

Above the second processing region located on the left side of the center of the processing vessel 5 in FIG. 2 , a plasma generating mechanism 8 is provided through a dielectric member 81 constituting a part of the ceiling of the processing vessel 5 . is installed. The dielectric member 81 is molded into a shape that fits into an opening formed in the ceiling of the processing container 5, and as shown in FIG. 4, the planar shape is fan-shaped, and the periphery is raised and bent outward. formed as a branch.

The plasma generating mechanism 8 includes an antenna 82 wound in a coil shape, and a high frequency power source 83 is connected to both ends of the antenna 82 . In addition, between the antenna 82 and the dielectric member 81, a Faraday shield 84, which is a conductive plate in which slits are formed to prevent electric field components among electric and magnetic fields generated from the antenna 82 from being directed toward the wafer W, is provided. ) is interposed. 84a is a dielectric plate.

3 shows a site lower than the ceiling of the processing container 5, the position of the antenna 82 is indicated by a dotted line for convenience in the second processing area.

Further, in the second processing region, as shown in FIG. 3 , a reaction gas nozzle 85 serving as a reaction gas supply unit is located upstream of the dielectric member 81 in the rotation direction of the rotary table 1, and the processing container 5 ) and is arranged parallel to the rotary table 1 through the side wall of the . The reactive gas nozzle 85 extends in the radial direction of the rotary table 1, and gas discharge holes are formed on the lower surface side at intervals in the longitudinal direction, when viewed along the radial direction of the rotary table 1, The arrangement area of the gas discharge hole is set so that the reaction gas is supplied to the entire passing area of the wafer W.

The proximal end of the reactive gas nozzle 85 is connected to a reactive gas supply system 86 including a reactive gas supply source and a group of gas supply control devices. If the film forming process is a process of forming a silicon nitride film, ammonia gas is used as a reaction gas, for example. In addition, a rare gas such as argon gas for plasma ignition may be supplied from the reactive gas nozzle 85 in addition to the reactive gas.

An exhaust groove 62 is formed on the periphery of the bottom of the processing vessel 5 so as to surround the rotary table 1, and in this groove 62, each process viewed from the rotational direction of the rotary table 1 is formed. An exhaust port 63 is formed at a position corresponding to the downstream end of the region. One end side of an exhaust pipe 64 (see FIG. 2 ) is connected to each exhaust port 63 , and a vacuum exhaust mechanism 65 , for example, a vacuum pump is connected to the other end side of the exhaust pipe 64 . In addition, as shown in FIG. 3 , on the sidewall of the processing container 5 facing one of the two first processing areas, a gate valve (not shown) opens and closes, and carries in and exits the wafer W ( 50) is formed, and wafers W are delivered and delivered between each loading table 2 by an external conveyance mechanism CA through this loading/unloading port 50.

In the transfer of the wafer W, in a state in which the rotary table 1 is stopped, a lift pin (not shown) is raised from the lower side of the mounting table 2 to lift the wafer W on the transfer mechanism CA. It is performed by lifting and receiving, and lowering a lifting pin after the conveyance mechanism CA retreats. To this end, in each mounting table 2, for example, passage holes for lift pins are formed at three locations in the circumferential direction, and the turn table 1 and wafer W loading/unloading ports correspond to the arrangement of the passage holes. A through hole is formed at the bottom of the processing container 5 in the processing region facing 50, and the lifting pin can move up and down through the through hole and the through hole. The lifting mechanism of the lifting pin is provided in the cover body 6, for example.

Here, the separation part 4 is explained. As shown in FIG. 5 , the separating portion 4 is a separating plate 41 having a fan-shaped planar shape and formed so that the dimension in the width direction gradually increases from the center side of the processing container 5 toward the outer circumferential side. is provided. The outer end side of the plate 41 for separation is bent downward in the shape of a key, extends to a lower side than the outer periphery of the turntable 1, and secures a gas separation function between processing regions. In addition, the inner end side of the separating plate 41 is fixed to the post 53, the upper surface is fixed to the ceiling of the processing container 5, and the lower surface side is spaced apart from each other in the width direction, and protrusions are formed. In other words, on the lower surface side of the plate 41 for separation, a groove portion 42 is formed in the central portion in the width direction.

In this groove 42, a separation gas nozzle 43 is disposed so as to pass through the side wall of the processing container 5 and extend parallel to the rotary table 1 and radially. In the separation gas nozzle 43, gas discharge holes 44 are formed at intervals in the longitudinal direction on the lower surface side, and when viewed along the radial direction of the rotary table 1, the separation gas nozzle 43 covers the entire passage area of the wafer W. A disposition area of the gas discharge hole 44 is set so that gas is supplied. Although not shown, the base end of the separation gas nozzle 43 is connected to a separation gas supply system including a separation gas supply source and a group of gas supply control devices. As the separation gas, for example, nitrogen gas which is an inert gas or the like is used.

As shown in FIG. 2 , the film forming apparatus includes a control unit 100 , and the control unit 100 includes a program for controlling the operation of the film forming apparatus described later. This program is meant to include processing procedures and processing recipes in which processing parameters are written. The program is stored in a storage medium such as a hard disk, compact disk, optical disk, USB memory, or memory card, and is downloaded to the controller 100.

Next, a process of forming a silicon nitride film (silicon nitride film) on the wafer W will be described as an example of the film formation process using the film formation apparatus described above. As shown in FIG. 6 , four wafers W are sequentially transferred to the loading table 2 through the loading/unloading port 50 by the transport mechanism CA in the vacuum transport chamber adjacent to the processing container 5 . send back to As described above, transfer of each wafer W is carried out via a lift pin (not shown), and after one wafer W is transported to the mounting table 2, the rotary table 1 is removed. is lifted and rotated in a clockwise direction to pass the subsequent wafer W to the loading table 2 adjacent to the loading table 2 . In the following description, codes W1 to W4 are assigned to each wafer W in order, starting with the wafer W first handed over to the loading table 2 . It is assumed that assigned codes are used when individually describing the four wafers, and "W" is used when comprehensively explaining.

In addition, for convenience of description, the four processing areas are sequentially referred to as processing area S1, processing area S2, processing area S3, and processing area S4 in a clockwise direction from the area facing the loading/unloading port 50. is allocated, the processing regions S1 and S3 are the first processing regions (regions to which source gas is supplied), and the processing regions S2 and S4 are the second processing regions (regions to which reactive gases are supplied). am.

Returning to FIG. 6 , after the wafers W1 to W4 are loaded on each loading platform 2, the loading/unloading port 50 is closed by a gate valve (not shown), and the inside of the processing container 5 is pressurized to a predetermined level. , for example, while adjusting to 100 Pa, as shown in Fig. 7, each mounting table 2 is rotated (wafers W1 to W4 are rotated). Until this time, the inside of the processing container 5 is heated to a predetermined temperature, for example, 400° C. by the heating unit 54 .

And in 1st processing area|region S1, S3, DCS gas which is source gas is discharged from the source gas nozzle 71 (refer FIG. 2 - FIG. 4) at the flow rate of 900 sccm, for example. Further, in the second processing regions S2 and S4, a mixed gas of ammonia gas, which is a reactive gas, and argon gas, which is a gas for plasma ignition, is discharged from the reactive gas nozzle 85 (see FIGS. 2 and 3). . As an example of the flow rate, the ammonia gas is 300 sccm and the argon gas is 2,000 sccm. Further, in the second processing regions S2 and S4, argon gas and ammonia gas are converted into plasma by supplying high-frequency power to the antenna 82.

Further, in the separator 4, nitrogen gas as a separation gas is discharged at a predetermined flow rate from the separation gas nozzle 43 shown in FIG. 5, thereby suppressing mixing of gases in adjacent processing regions. That is, each processing area is separated with respect to the atmosphere. In addition, since the exhaust port 63 is formed at the downstream end of the processing area when viewed from the rotational direction of the turntable 1 for each processing area, the gas supplied to each processing area flows downstream through the processing area, and the separation unit It is exhausted together with the separation gas flowing out from (4).

The DCS gas is adsorbed on the surfaces of the wafers W4 and W2 positioned in the first processing regions S1 and S3, respectively. At this time, since each of the wafers W1 to W4 is rotated by the already described magnetic gear mechanism, the DCS gas is adsorbed to the wafers W4 and W2 with good uniformity in the circumferential direction.

Active species generated by plasma conversion of ammonia are supplied to the surfaces of the wafers W3 and W1 located in the second processing regions S2 and S4, respectively. Since the DCS gas has not yet been adsorbed at this point, the reaction no product is produced. In addition, supply of gas and generation of plasma in the second processing regions S2 and S4 occur after the next rotation (intermittent rotation) of the rotary table 1, that is, when the wafers W4 and W2 to which the DCS gas has already been adsorbed It may be performed after being located in the second processing areas S2 and S4.

After discharging the DCS gas from the source gas nozzle 71 (see FIG. 3) in the first processing regions S1 and S3, for example, for 10 seconds, the rotary table 1 is rotated clockwise by 90 degrees ( 8), each of the wafers W1 to W4 is moved to a processing area adjacent to the processing area previously located (in detail, adjacent in a clockwise direction when viewed from the rotational direction of the rotary table 1). (Idle). The arrangement of the wafers W1 to W4 shown in FIG. 9 is the state after the rotation table 1 is rotated, and the wafers W1, W4, W3, and W2 are positioned in the processing regions S1 to S4, respectively.

The wafers W1, W4, W3, and W2 are subjected to processing in each of the processing regions S1 to S4 while rotating. Since the wafers W4 and W2 have already adsorbed DCS gas, which is the source gas, active species of ammonia gas, which is the reactive gas, react with the DCS gas on the wafers W4 and W2 in the second processing regions S2 and S4. A silicon nitride layer, which is a reaction product, is formed.

In the first processing regions S1 and S3, the DCS gas is discharged from the source gas nozzle 71, and the DCS gas is adsorbed to the wafers W1 and W3 located in the first processing regions S1 and S3, respectively. .

In the second processing regions S2 and S4, the time required to generate a reaction product by supplying active species of ammonia gas onto the wafer W and reacting with DCS is, for example, 20 seconds. The required time means the time required to sufficiently react with DCS (sufficiently nitride the surface of the wafer W) and obtain a film quality that meets the specifications. On the other hand, the time required to adsorb the DCS gas to the surface of the wafer W is, for example, 10 seconds, which is shorter than the time required for the reaction of ammonia gas with active species. Therefore, after the wafers W1 and W3 are positioned in the first processing regions S1 and S3 and the DCS gas is discharged from the source gas nozzle 71 for a required period of time, the discharge of the DCS gas is stopped and the wafers W1 and W3 are discharged. W3) waits in the first processing areas S1 and S3 until the end of the processing in the second processing areas S2 and S4, respectively.

On the other hand, since the reactions in the second processing regions S2 and S4 are rate-limited to the progress of the process, for example, the supply of ammonia gas and the generation of plasma are sequentially performed for the four wafers W1 to W4. This continues until the film forming process of is completed.

When the processing of the wafers W4 and W2 is performed in the second processing regions S2 and S4, that is, when a predetermined time period according to the time required for the reaction elapses, as shown in FIG. 10, the rotation table 1 ) is rotated clockwise by 90 degrees, and each of the wafers W4, W3, W2, and W1 moves to the downstream processing regions S3, S4, S1, and S2, respectively. Fig. 11 shows the state after movement. Similarly, while the wafers W4, W3, W2, and W1 are rotated, the DCS gas is adsorbed to the wafers W2 and W4 in the first processing regions S1 and S3, respectively, and the second processing region In (S2, S4), a reaction process by an active species of ammonia gas is performed on the wafers W1 and W3, respectively.

Then, as shown in Figs. 12 and 13, the rotary table 1 rotates 90 degrees clockwise. While the wafers W4 and W2 rotate, an active species of ammonia is supplied from the second processing regions S4 and S2, respectively, and reacts with the DCS gas already adsorbed in the first processing regions S3 and S1 to form a silicon nitride layer. this is layered In the wafers W1 and W3, the DCS gas is adsorbed on the silicon nitride layer already formed in the first processing regions S1 and S3, respectively. Then, when the set time has elapsed, as shown in Fig. 14, the rotary table 1 rotates and returns to the state shown in Fig. 6.

Thereafter, in the same manner, the rotation table 1 is sequentially stopped for a set time, and an operation of intermittently rotating clockwise by 90 degrees is repeated for a set number of times. In addition, assuming that the last stop position of the rotary table 1 is the state shown in FIG. 6 , when processing is being performed in the second processing areas S2 and S4, in order to eliminate unnecessary consumption of raw material gas, the first processing area In (S1, S3), source gas is not discharged. When a series of film formation processes are completed in this way and a silicon nitride film is formed on each wafer W by ALD, each wafer W ) is carried out from the processing vessel 5.

According to the above-described embodiment, the inside of the processing container 5 is divided into two equal intervals along the circumferential direction of the rotary table 1, and the first processing area and the second processing area are separated at equal intervals via the separator 4, respectively. They are formed alternately. Then, the loading table 2 is placed so that each wafer W is positioned in each processing area, and the rotation table 1 is intermittently rotated to place each wafer W in the first processing area and the second processing area. Alternately positioned to form a silicon nitride film by ALD. Therefore, the cycle of adsorption of DCS gas as raw material gas and reaction by active species of ammonia gas as reaction gas can be performed twice during one rotation of the rotary table 1, so there is an effect of high productivity.

Further, in each of the first processing region and the second processing region, since the processing is performed while rotating the wafer W, the uniformity of the film thickness and film quality in the circumferential direction of the wafer W is good. In addition, since the turntable 1 is rotated intermittently in accordance with the time required for the reaction by the active species of ammonia gas, which requires a longer time than the time required for adsorption of the DCS gas, the nitriding treatment can be sufficiently performed, resulting in quality This high membrane can be obtained. And, since the discharge of the DCS gas is stopped while waiting until the treatment with the ammonia gas is completed after discharging the DCS gas for the required time, it contributes to reducing the consumption of the DCS gas.

(Modified example of the first embodiment)

In the above-described embodiment, one wafer W is positioned in each of the four processing areas. However, as shown in FIG. 15, eight mounting tables 2 are installed, and each of the four processing areas It may be configured so that two wafers W are positioned. In Fig. 15, 50a and 50b denote intake ports. Also, when the turntable 1 is stopped, the number of wafers W placed in each processing area may be three or four or more.

Also, the number of each of the first processing region and the second processing region is not limited to two, and may be three or more.

In the above-described embodiment, the ammonia gas is turned into plasma, but the ammonia gas may be supplied to the wafer W without turning it into plasma.

In the above-described embodiment, after the DCS gas is discharged for a set time, the discharge is stopped until the reaction with the ammonia gas is completed. Even if the DCS gas is discharged for a necessary period of time, for example, the adsorption of the DCS gas and the reaction by the ammonia gas are terminated at the same timing, the consumption of the raw material gas can be suppressed. Further, a case in which the DCS gas is left flowing until a series of film formation processes on the wafer W is completed is also included in the scope of the present invention.

The film formation process is not limited to film formation of a silicon nitride film, and may be, for example, a process of forming a silicon oxide film using, for example, nonstertial butylaminosilane gas and oxygen gas or ozone gas as a reactive gas as a silicon raw material gas. do. Alternatively, a process of forming a titanium nitride film (titanium nitride film) by using a titanium tetrachloride gas as a source gas and ammonia gas as a reaction gas may be used.

One of the driven gear unit 31 and the drive gear unit 32, which are rotation mechanisms, may be made of a non-magnetized magnetic material. Alternatively, the driven gear unit 31 may be configured to rotate horizontally, and the driving gear unit 32 may be disposed on the lower side of the driven gear unit 31 so as to face the driven gear unit 31 . Further, the rotation mechanism is not limited to one using magnetism, and may have a configuration in which a driven gear unit and a driving gear unit are provided as mechanical gears, and the driving gear unit advances and retreats with respect to the moving path of the driven gear unit. Alternatively, the rotation mechanism may have a configuration in which a rotation mechanism is provided for each rotation shaft 21 .

(Second Embodiment)

A film forming apparatus using another example of a rotation mechanism for rotating the mounting table 2 will be described as a second embodiment of the present invention with reference to FIGS. 16 to 18 . In the first embodiment, the drive gear portion 32 is disposed at four positions along the circumferential direction of the rotary table 1, but in the second embodiment, the drive gear portion 32 orbits the rotary table 1. It is installed along the track and over the entire circumference. That is, the drive gear unit 90 is provided so as to face the orbital orbit of the driven gear unit 36 and has an annular plate-like body 91 having a circular opening 91a in its central portion, The center of the opening 91a is arranged to align with the center of rotation of the rotary table 1. On the upper surface of the drive gear unit 90, along the orbital orbit of the driven gear unit 36, along the entire circumference, an N-pole portion (indicated by oblique lines) 92 and an S-pole portion 93, which are magnetic pole portions made of permanent magnets, are are placed alternately.

On the lower surface of the driven gear unit 36, along the direction of rotation, a rectangular N-pole portion 37 (indicated by oblique lines) and an S-pole portion 38, which are magnetic pole portions made of permanent magnets, are provided for the rotation of the driven gear unit 36. They are alternately arranged along the circumferential direction. The N-pole portion 92 and the S-pole portion 93 of the drive gear portion 90 are arranged on a surface opposite to the lower surface of the driven gear portion 36 . Fig. 17 is a diagram drawn in correspondence with the magnetic pole part of one driven gear part 36 and the magnetic pole part of the drive gear part 90 below it.

As shown in FIG. 18 , the driven gear part 36 is disposed inside the cover body 6 (vacuum atmosphere side), and the driving gear part 90 is placed outside the cover body 6 (atmospheric side). ) is placed in That is, between the driven gear part 36 and the driving gear part 90 is partitioned by the cover body 6, for example, the cover body 6 made of aluminum or SUS which is a material through which lines of magnetic force pass. The drive gear unit 90 is configured to be rotatable by an annular direct drive motor (DD motor) 94 on a holder 95 installed so as to surround the rotation shaft 13 of the rotation support 12. . 18, 13a is a bearing part.

In such a rotation mechanism, the driven gear unit 36 stops at a position determined by the combined action of the attraction force and the repulsive force between the magnetic pole portion of the driven gear unit 36 and the magnetic pole portion of the drive gear unit 90. . Therefore, when the revolution speed of the driven gear unit 36 (the rotational speed (rpm) of the rotary table 1) and the rotational speed of the drive gear unit 90 are the same, the driven gear unit 36 does not rotate, but both When a difference occurs in the number of revolutions, the driven gear unit 36 rotates, and its rotation speed is determined according to the difference in the number of revolutions. In addition, when the rotational speed of the drive gear part 90 is greater than the rotational speed of the rotary table 1, the driven gear part 36 rotates clockwise in FIG.

Further, in the first embodiment, the lifting pins used when carrying in and out of the wafer W are not shown, but FIG. 18 shows the lifting pins. For example, three elevating pins 96 are provided so as not to interfere with the moving path of the bearing portion 22 by the elevating mechanism 97, and the front end portion is on standby within the cover body 6. When transferring the wafers W between the external transfer mechanism CA, the lifting pins 96 move the bottom plate of the processing container 5, the heating unit 54, the rotary table 1, and each load. A wafer W is held through a hole formed in the stand 2 . Airtightness is maintained between the elevating pin 96 and the cover body 6 by, for example, a bellows. In Fig. 16, a hole portion (through hole) formed in the mounting table 2 is indicated by a numeral 96a.

(Third Embodiment)

In the above-described embodiment, the rotation table 1 is rotated intermittently to alternately position each wafer W in the first processing area and the second processing area. If this operation mode is referred to as an intermittent rotation mode, the third embodiment of the present invention provides a continuous rotation mode in which the film forming process is performed by continuously rotating the rotary table 1 in addition to the intermittent rotation mode, and both modes are It is designed so that you can choose.

19 shows the arrangement of wafers W when the continuous rotation mode is selected. In the first embodiment, as shown in FIGS. 3 and 6 , a loading table is placed so that one wafer W is positioned in each of the first processing areas S1 and S3 and the second processing areas S2 and S4. (2) is placed. In the example of FIG. 15 , the mounting table 2 is arranged so that two wafers W are positioned in each of the processing regions S1 to S4.

On the other hand, in the third embodiment, in a state in which, for example, one wafer or two wafers (see Fig. 19) are positioned in each of the respective processing regions S1 to S4, each of the processing regions S1 to S4 ), that is, the mounting table 2 is arranged so that the wafers W are also located in each of the four separation units 4. Accordingly, when two wafers W are placed in each of the processing regions S1 to S4, 12 mounting tables 2 are disposed.

19 shows the position of the wafer W at the moment when the wafer W is being processed in the continuous rotation mode and two wafers W are positioned in each of the processing regions S1 to S4. indicates In the continuous rotation mode, product wafers W, which are wafers to be processed, are loaded on all 12 mounting tables 2 . In this example, the loading/unloading port 50 is configured so that two wafers W can pass through at once, and the two wafers W are held in a horizontal arrangement in an external transport mechanism (not shown), It is simultaneously passed to two loading tables 2 adjacent to each other. The set of lifting pins 96 already described is installed at a position corresponding to the stop position of the two mounting platforms 2, and the wafer holding member at the front end of the transfer mechanism has a shape that does not interfere with the lifting pins 96 in plan view. It consists of Accordingly, the transfer of wafers W is performed between the transport mechanism and the loading table 2 by the cooperative action of the transport mechanism and the lifting pins 96 .

In the continuous rotation mode, after the processing target wafers W are loaded on all of the loading table 2 and the loading/unloading port 50 is closed, the rotary table 1 is rotated to rotate (idling) the loading table 2. While doing so, the loading platform 2 is rotated to establish process conditions. That is, as described above in the first embodiment, the inside of the processing chamber 5 is set to a predetermined pressure and the wafer W is heated to a predetermined temperature, and in the first processing regions S1 and S3 , DCS gas as source gas is supplied, and in the second processing regions S2 and S4, the previously described mixed gas is supplied to form plasma. In addition, separation gas is supplied to the separation unit 4 .

Each wafer W alternately and continuously passes through the first processing region S1 (S3) and the second processing region S2 (S4), so that the DCS gas is adsorbed and the adsorbed DCS gas and ammonia gas are absorbed. Formation of the silicon nitride layer, which is a reaction product by reaction with the active species, is repeated, and the silicon nitride layer is stacked. The continuous rotation mode is different from the intermittent rotation mode in that the processing target wafers W are loaded on all 12 mounting tables 2 and each mounting table 2 is continuously rotated.

Next, when the intermittent rotation mode is selected, as shown in FIG. 20, two to-be-processed wafers W are positioned in each of the first processing regions S1 and S3 and the second processing regions S2 and S4, The processing target wafer W is loaded on the loading table 2 . In this case, the processing target wafer W is not loaded on the loading table 2 located in the separator 4, but dummy wafers DW (wafers indicated by hatched lines in FIG. 20) are loaded without being emptied. The reason for this is as follows. A purge gas (not shown) is supplied between the rotary table 1 and the heating unit 54, and if the wafer W is not placed on the loading table 2, if left as it is, the loading table 2 The purge gas flows into the processing atmosphere through the hole portion 96a through which the elevating pins 96 formed therein pass. For this reason, the dummy wafer DW is loaded on the mounting table 2 .

In the intermittent rotation mode, the wafer W is processed in a stationary state in each processing area S1 to S4, and in the continuous rotation mode, the wafer W is processed while moving in each processing area S1 to S4. , the film quality of the silicon nitride film is better when it is formed in the intermittent rotation mode than in the continuous rotation mode. On the other hand, in the continuous rotation mode, the number of wafers W mounted is four more than in the case of the intermittent rotation mode, and processing is performed by continuous rotation, so that the same film thickness can be obtained than in the intermittent rotation mode. (5) The residence time within may be short. Therefore, in the continuous rotation mode, a higher throughput is obtained than in the intermittent rotation mode. For this reason, there is an advantage that one of the two modes can be set according to the lot of wafers, such as selecting the intermittent rotation mode when priority is given to high-quality films and selecting the continuous rotation mode when priority is given to throughput.

21 shows a substrate processing system including two film forming apparatuses described above. In FIG. 21 , 301 denotes a carrier loading table, 302 a standby transfer chamber, 300 a first wafer transfer mechanism, 303 and 304 load lock chambers, 305 a vacuum transfer chamber, and 306 a second wafer transfer mechanism. Further, at a position on the right side facing the standby transfer chamber 302, for example, a holding shelf 307 is provided that accommodates a plurality of sheets of at least four dummy wafers DW.

For example, when the carrier C, which is a FOUP accommodating a plurality of wafers W, is loaded into the carrier mounting table 301, the cover on the front surface of the carrier C is removed, and the first wafer transport mechanism 300 As a result, the wafer W is taken out, and the wafer W is carried into the processing container 5 through the load lock chamber 303 or 304 and the second wafer transfer mechanism 306 . The second wafer transport mechanism 306 is configured to hold, for example, two wafers W in a horizontal arrangement and transfer them to the processing container 5 and the load lock chamber 303 or 304 as a group. there is.

Reference numeral 200 is a control unit and includes an operation mode selector 201 that selects an intermittent rotation mode or a continuous rotation mode. When the intermittent rotation mode is selected, the first wafer transport mechanism 300 takes out the dummy wafer DW, carries it into the processing container 5 through the previously described path, and places it in the position shown in FIG. 20 .

The rotary table 1 used in the above embodiment serves to transfer heat from the heater 54 to the wafer W, and is configured to be supported by the support 12 for rotating the mounting table 2. However, the rotary table 1 may be fixed. In this case, the plate-like body corresponding to the rotary table 1 functions as a heat transfer plate, but it is preferable to support the central portion with a support post. In this case, a direct drive motor (DD motor) is used as the rotating mechanism for orbiting the mounting table 2 so as to surround the periphery of the support column. In addition, a gap is formed for the rotation axis 21 of the mounting table 2 to move in the circumferential direction of the heat transfer plate fixed to the post, and thus the heat transfer plate is separated into a central portion and an outer ring-shaped portion. Therefore, the present invention does not necessarily require a rotary table.

The present invention is not limited to a film formation process by ALD, and a first film is formed by a CVD process by supplying a first gas to a first processing region, and then supplying a second gas to a second processing region to form a CVD process. You may apply when forming a 2nd film by a process. In this case, a plurality of first films and second films are alternately laminated, and it can be used, for example, for manufacturing a three-dimensional NAND circuit. In this case, when two or three or more types of gases are used as the first gas, the gas corresponds to the first gas, and when two or three or more types of gases are used as the second gas, the gas corresponds to the first gas. Corresponds to the second gas.

Further, the rotation of the rotary table 1 is not limited to intermittent rotation in one direction, but clockwise rotation and counterclockwise rotation may be alternately performed.

1: rotary table 12: rotary support
13: rotation axis 2: loading table
21: rotation axis 31: driven gear unit
32: drive gear unit 4: separation unit
5: processing container 53: heating unit
54: gap 6: cover body
63: exhaust port 71: source gas nozzle
8: Plasma generating mechanism 81: Dielectric member
82: antenna 85: reaction gas nozzle
W: semiconductor wafer S1, S3: first processing area
S2, S4: second processing area

Claims (20)

A film forming apparatus for forming a thin film on a substrate by performing a plurality of cycles of alternately supplying a first gas and a second gas, which are processing gases, to a substrate in a processing container that creates a vacuum atmosphere, comprising:
a first processing region formed along a circumferential direction of the processing container and configured to process a substrate by supplying the first gas;
a second processing region formed along the circumferential direction and supplying the second gas to process the substrate;
a separator for separating the first processing region from the second processing region;
Loading units configured to be able to revolve along the circumferential direction and disposed in plurality along the circumferential direction for loading substrates, respectively;
And a control unit for intermittently revolving the loading part so that the substrate is alternately positioned in the first processing region and the second processing region in a state in which the revolution is stopped,
The loading unit is arranged so that two or more identical substrates are located in each of the first processing area and the second processing area when the loading unit stops revolutionizing;
The area between adjacent substrates in the circumferential direction with the separator interposed therebetween has a size equal to or greater than one substrate;
The film forming apparatus, wherein the number of stacking units is set such that when two or more identical substrates are positioned in each of the first processing area and the second processing area, no substrate stacking unit is located in the separation unit. According to claim 1,
The first gas is a source gas that is a source of a thin film to be adsorbed onto a substrate, and the second gas is a reactive gas that reacts with the source gas to generate a reaction product. According to claim 2,
The film forming apparatus of claim 1 , wherein the controller stops revolution of the loading unit and starts supplying the reactive gas when the substrate adsorbed with the source gas in the first processing region is in a second processing region. According to claim 2,
The film forming apparatus of claim 1 , wherein the second processing region includes a plasma generator, and the reaction gas is converted into plasma by the plasma generator and supplied. According to claim 4,
The control unit stops revolution of the loading unit, and when the substrate adsorbed with the source gas in the first processing area is in the second processing area, the reaction gas is supplied and plasma generation is started by the plasma generating unit. A film forming device that is controlled to do so. According to claim 1,
The required supply time of the first gas in the first processing region and the required supply time of the second gas in the second processing region are different from each other, and the rotary table adjusts to the longer required gas supply time. Stationary tabernacle equipment. According to claim 6,
When the supply time for supplying the necessary first gas is shorter than the supply time for supplying the necessary second gas, the supply time for the first gas is set shorter than the supply time for the second gas, and Where a supply time for supplying the two gases is shorter than a supply time for supplying the required first gas, a supply time for the second gas is set shorter than a supply time for the first gas. According to claim 1,
and a rotation mechanism for rotating the mounting unit, wherein the mounting unit on which the substrate is mounted rotates at least when the processing gas is being supplied to the substrate. According to claim 1,
A rotary table rotating in a circumferential direction of the processing container;
The plurality of stacking units are disposed on the upper surface side of the rotary table. According to any one of claims 1 to 9,
If the operation mode of intermittently revolving the loading part so that the substrate is alternately positioned in a stopped state in the first processing region and the second processing region is an intermittent rotation mode,
The control unit is configured to select one of a continuous rotation mode in which the loading unit continuously revolves so that the substrate continuously passes through the first processing region and the second processing region, and the intermittent rotation mode. . A film formation method of forming a thin film on a substrate by alternately supplying a first gas and a second gas, which are processing gases, to a substrate in a processing container that creates a vacuum atmosphere, the method comprising the steps of:
forming a first processing region in the processing container along a circumferential direction of the processing container and forming a second processing region with a separation region between the first processing region and the first processing region along the circumferential direction;
While being configured to be able to revolve along the circumferential direction, a plurality of them are disposed along the circumferential direction, and a loading unit for loading each substrate is installed,
The loading unit is arranged so that two or more identical substrates are located in each of the first processing area and the second processing area when the loading unit stops revolutionizing;
The area between adjacent substrates in the circumferential direction with the separator interposed therebetween has a size equal to or greater than one substrate;
When two or more identical substrates are positioned in each of the first processing area and the second processing area, using a film forming apparatus in which the number of stacking units is set such that no substrate stacking unit is located in the separation area,
The loading unit is intermittently revolved so that the substrate is alternately positioned in the first processing region and the second processing region in a state in which the revolution is stopped, and the first gas is applied to the first processing region and the second processing region, respectively. and a step of supplying the second gas. According to claim 11,
The first gas is a source gas that is a source of a thin film adsorbed onto a substrate, and the second gas is a reactive gas that reacts with the source gas to generate a reaction product. According to claim 12,
The deposition method of claim 1 , wherein revolution of the loading unit is stopped, and supply of the reaction gas is started when the substrate to which the source gas is adsorbed in the first processing region is located in a second processing region. According to claim 12,
The film forming method of claim 1 , wherein the second processing region includes a plasma generator, and the reaction gas is converted into plasma by the plasma generator and supplied. According to claim 14,
The method of forming a film in which revolution of the loading unit is stopped and, when the substrate to which the source gas is adsorbed in the first processing area is located in a second processing area, the reaction gas is supplied and plasma generation is started by the plasma generating unit. According to claim 11,
The required supply time of the first gas in the first processing region and the required supply time of the second gas in the second processing region are different from each other, and the rotary table adjusts to the longer required gas supply time. Stationary tabernacle method. According to claim 16,
When the supply time for supplying the necessary first gas is shorter than the supply time for supplying the necessary second gas, the supply time for the first gas is set shorter than the supply time for the second gas, and The film deposition method of claim 1 , wherein when a supply time for supplying the two gases is shorter than a supply time for supplying the necessary first gas, the supply time for the second gas is set shorter than the supply time for the first gas. According to claim 11,
and a rotation mechanism for rotating the mounting unit, wherein the mounting unit on which the substrate is mounted rotates at least when the processing gas is being supplied to the substrate. According to claim 11,
A rotary table rotating in a circumferential direction of the processing container;
The film forming method of claim 1, wherein the plurality of stacking units are arranged on an upper surface side of the rotary table. According to any one of claims 11 to 19,
If the operation mode of intermittently revolving the loading part so that the substrate is alternately positioned in a stopped state in the first processing region and the second processing region is an intermittent rotation mode,
After the substrate film formation process is performed by selecting one of the continuous rotation mode in which the mounting unit continuously revolves so that the substrate continuously passes through the first processing region and the second processing region, and the intermittent rotation mode, the subsequent A film forming method in which a film forming process is performed on a substrate by selecting the other of the continuous rotation mode and the intermittent rotation mode.

Images