Nozzle and substrate processing apparatus using same

A nozzle for supplying a fluid includes a tubular part including a tubular passage thereinside and a fluid discharge surface having a plurality of fluid discharge holes formed therein along a lengthwise direction of the tubular passage. A partition plate is provided in the tubular passage and extends along the lengthwise direction so as to partition the tubular passage into a first area including the fluid discharge surface and a second area without the fluid discharge surface. The partition plate has distribution holes whose number is less than a number of the plurality of fluid discharge holes in the lengthwise direction. A fluid introduction passage is in communication with the second area.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based upon and claims the benefit of priority of Japanese Patent Application No. 2014-234500, filed on Nov. 19, 2014, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a nozzle and a substrate processing apparatus using the same.

2. Description of the Related Art

Conventionally, the following process is known as a film deposition method in a semiconductor manufacturing process. In the process, one or more atomic layers or molecular layers are formed on a surface of a substrate such as a semiconductor wafer (which is hereinafter referred to as just a “wafer”) by causing a first reaction gas to adsorb on the surface of the wafer and then by switching a supplying gas from the first reaction gas to a second reaction gas to react with the first reaction gas on the surface of the wafer in a vacuum atmosphere. Then, a film is deposited on the substrate by repeating the above process many times so as to deposit the atomic layers or the molecular layers. This process is referred to as, for example, ALD (Atomic Layer Deposition) or MLD (Molecular Layer Deposition), which is an effective method that can respond to a demand of manufacturing a thinner film because the method can precisely control a film thickness depending on the number of cycles and achieve preferable uniformity of film quality across the surface of the wafer.

A film deposition of a gate oxide used in a gate of a MOS (Metal Oxide Semiconductor) transistor is cited as an example of preferable usage of such a film deposition method. For example, when depositing a silicon oxide film (SiO2film), bis(tertiary-butyl-amino)silane (which is hereinafter referred to as “BTBAS”) gas or the like is used as the first reaction gas (source gas), and ozone (O3) gas or the like is used as the second reaction gas (oxidation gas).

For example, Japanese Laid-Open Patent Application Publication No. 2010-56477 discloses a film deposition apparatus to implement the ALD or MLD. The disclosed film deposition apparatus implements the film deposition method by placing a plurality of substrates on a circular turntable in a circumferential direction provided in a process chamber, in which multiple process areas that supply different reaction gases from reaction gas nozzles provided in a side wall of the process chamber are provided separately from each other in the circumferential direction, and by supplying the different reaction gases in the process areas while rotating the turntable.

In the meantime, as the substrates have been increasing in size in recent years, for example, when the substrates are wafers, film depositions are performed on substrates having a diameter of 300 mm. Hence, according to the configuration of the gas nozzle provided in the side wall of the process chamber as discussed above, the length of the gas nozzles becomes long because the gas nozzles need to extend from the side wall to the vicinity of the center of the turntable in order to supply the reaction gases to the entire surfaces of the wafers placed on the turntable. Accordingly, when base portions of the gas nozzles are fixed to the side wall of the process chamber, the moment of tip portions of the gas nozzles become great, which causes the tip portions to be likely to descend due to its own weight.

When the gas nozzles are long, discharge rates of the gases from the gas nozzles become greater at the base portions that are closer to gas supply sources than at the tip portions of the gas nozzles. This causes a problem of making density of the reaction gases lower in the central area than in the peripheral area. To solve the problem, Japanese Laid-Open Patent Application Publication No. 2010-135510 discloses a film deposition apparatus configured to be able to adjust a distance between a surface of a wafer and a gas nozzle in a lengthwise direction of the gas nozzle by adjusting an inclination of the gas nozzle to the horizontal axis.

In the meantime, high-k processes for depositing high dielectric films are often used in recent years. Gas species for film deposition used in the high-k processes have caused a problem of deteriorating film properties because the gas species have such poor resistance properties as source gases that the gas species cannot sustain the same condition in a high temperature in the process chamber as the condition in a low temperature, and further because self-decomposition of the gas species occurs in a gas phase before adsorbing on a wafer. More specifically, in cases where the gas nozzle is provided in the side wall of the process chamber and extends toward the center of the turntable, when a source gas is supplied from the side wall, the self-decomposition of the source gas occurs before the source gas reaches the tip portion of the gas nozzle due to the high temperature in the process chamber, and a sufficient film deposition is not performed at and around the center of the turntable, which causes a problem of deteriorating uniformity of film thickness across the surface of the wafer.

Such a problem cannot be solved by just adjusting the inclination of the gas nozzle as disclosed in Japanese Laid-Open Patent Application Publication No. 2010-135510, and using a nozzle structured to prevent the self-decomposition of a source gas is needed.

SUMMARY OF THE INVENTION

Accordingly, embodiments of the present invention may provide a nozzle and a substrate processing apparatus that can prevent self-decomposition of a source gas and supply the source gas in a favorable condition.

According to an embodiment of the present invention, there is provided a nozzle for supplying a fluid that includes a tubular part including a tubular passage thereinside and a fluid discharge surface having a plurality of fluid discharge holes formed therein along a lengthwise direction of the tubular passage. A partition plate is provided in the tubular passage and extends along the lengthwise direction so as to partition the tubular passage into a first area including the fluid discharge surface and a second area without the fluid discharge surface. The partition plate has distribution holes whose number is less than a number of the plurality of fluid discharge holes in the lengthwise direction. A fluid introduction passage is in communication with the second area.

According to another embodiment of the present invention, there is provided a substrate processing apparatus that includes a process chamber and a susceptor provided in the process chamber and configured to hold a substrate on a surface thereof. A nozzle including a fluid discharge surface is provided so that the fluid discharge surface faces the surface of the susceptor. The nozzle includes a tubular part including a tubular passage thereinside and a fluid discharge surface having a plurality of fluid discharge holes formed therein along a lengthwise direction of the tubular passage. A partition plate is provided in the tubular passage and extends along the lengthwise direction so as to partition the tubular passage into a first area including the fluid discharge surface and a second area without the fluid discharge surface. The partition plate has distribution holes whose number is less than a number of the plurality of fluid discharge holes in the lengthwise direction. A fluid introduction passage is in communication with the second area.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description is given below of embodiments of the present invention with reference to accompanying drawings.

FIG. 1is a cross-sectional view illustrating a configuration of an example of a nozzle according to an embodiment of the present invention. A nozzle30of the embodiment of the present invention includes a tubular part300, a tubular passage310, a fluid introduction passage320, fluid discharge holes330, and a partition plate340. The tubular part300includes the tubular passage310thereinside, and the fluid discharge hole330is formed in a lower surface of the tubular passage310. The partition plate340is provided between an upper surface and the lower surface inside the tubular passage310. The partition plate340partitions the tubular passage310into a fluid discharge area311including a fluid discharge surface311in which the fluid discharge holes330are formed, and a fluid flow area312without a surface in which the fluid discharge holes330is formed. Moreover, the tubular passage310includes a folded passage313that communicates the fluid discharge area311with the fluid flow area312in the vicinity of the tip. The partition plate340includes a partition part341formed into a plate-like shape, and distribution holes342are formed in predetermined locations of the partition part341. A base portion of the tubular part300is connected to the fluid introduction passage320. Because the nozzle30is often used as a unit to inject a fluid such as a gas into a process chamber when used in a substrate processing apparatus, the nozzle30may be referred to as an injector.

The tubular part300is a tube-shaped portion including the tubular passage310that allows a fluid to flow through the inside thereof. A cross section of the tubular part300may be formed into a variety of shapes depending on the intended purpose. For example, the cross section of the tubular part300may be formed into a quadrangle, preferably a rectangle. Although the nozzle30of the present embodiment can be used for a variety of intended purposes for supplying a fluid, for example, the nozzle30may be used in a substrate processing apparatus that processes a wafer and the like. When the nozzle30of the embodiment is used in the substrate processing apparatus and the nozzle30having the multiple fluid discharge holes330in a width direction as well as in a lengthwise direction of the tubular part300is provided horizontally facing a surface of a wafer, all distances from the multiple fluid discharge holes330to the surface of the wafer are preferred to be made equal. Accordingly, the tubular part300may be formed into a quadrangle such as a rectangle so as to cause the distance between a lower surface of the tubular part300facing the wafer and the surface of the wafer to be constant in the entire area of the lower surface of the tubular part300, in other words, so as to make the lower surface of the tubular part300parallel to the surface of the wafer. However, forming the tubular part300into a circular tube shape or a cylindrical shape is naturally possible, and the tubular part300can be formed into a variety of shapes depending on the intended purpose.

The plurality of fluid discharge holes330is provided in the lower surface of the tubular part300. The fluid discharge holes330penetrate through the lower surface of the tubular part300so as to be in communication with the outside, and function as holes for discharging and supplying a fluid flowing through the tubular passage310to an area facing the fluid discharge holes330. The fluid discharge holes330may be formed into through holes vertically penetrating the wall surface of the tubular part300. The number of the fluid discharge holes330may be set at a variety of proper numbers depending on the intended purpose. For example, when supplying a source gas for film deposition to the surface of the wafer, hundreds of the fluid discharge holes330, for example, about seven hundred of the fluid discharge holes330, are provided. Although the fluid discharge holes330may be formed into a variety of shapes depending on the intended purpose, for example, the fluid discharge holes330may be formed to have a circular cross-sectional shape.

Although the fluid discharge holes330may be arranged variously, for example, the fluid discharge holes330may be arranged at predetermined intervals in the lengthwise direction. The fluid discharge holes330may be arranged at regular intervals in the lengthwise direction of the nozzle30in order to ensure uniform supply of the fluid in the lengthwise direction. Furthermore, the plurality of fluid discharge holes330may be formed in the width direction of the nozzle30, and multiple lines of the fluid discharge holes330arranged in the lengthwise direction are formed in the width direction so as to form multiple rows. Details on this point are described later.

The partition plate340is provided in the intermediate position between the upper surface and the lower surface of the tubular passage310so as to partition the inner space and the inner surface of the tubular passage310by being bonded to the inner surface of the tubular part30forming the tubular passage310. More specifically, the partition plate340partitions and separates the inner space and the inner surface of the tubular passage310into the fluid discharge area311on the fluid discharge hole side including the fluid discharge holes330and the fluid flow area312opposite to the fluid discharge holes330without the fluid discharge holes330. In addition, the partition plate340is not formed at the tip of the tubular passage310, thereby forming the folded passage313to cause the fluid discharge area311to be in communication with the fluid flow area312.

The partition plate340includes the plate-like partition part341and the distribution holes342formed in the partition part341. Only the number of distribution holes342less than the number of fluid discharge holes330is formed in the lengthwise direction of the tubular part300and the tubular passage310. More specifically, the distribution holes342have a diameter larger than that of the fluid discharge holes330, and are formed to be arranged at intervals greater than the intervals between the adjacent fluid discharge holes330in the lengthwise direction of the tubular part300and the tubular passage310. Hence, the number of the distribution holes342is consequently less than the number of the fluid discharge holes330.

The partition plate340is provided to prevent a fluid such as a source gas from not being able to reach the tip portion due to the self-decomposition of the source gas in the middle of the tubular passage310when the fluid such as the source gas is introduced from the fluid introduction passage320. More specifically, when a film deposition process and the like are performed on a wafer in the process chamber by using the conventional nozzle without the partition plate340, a phenomenon of the self-decomposition of the source gas sometimes occurs before the source gas reaches the tip of the nozzle due to the relationship among the high temperature, the pressure in the process chamber and the flow rate and the like of the supplied source gas, and the source gas is not sufficiently supplied to the tip of the nozzle, thereby decreasing the uniformity of film thickness across the surface of the film deposited on the wafer. In order to prevent such a phenomenon, the nozzle30of the embodiment includes the partition plate340in the tubular passage310, thereby preventing the self-decomposition of the source gas. More specifically, by providing the partition plate340, the source gas introduced from the fluid introduction passage320enters the fluid flow area312, and a part of the source gas goes along the fluid flow area312, reaches the fluid discharge area311by way of the folded passage313, reaches the fluid discharge holes330from the tip portion to the base portion in sequence, and is discharged therefrom. In other words, the tubular passage310including a folded structure can be formed by providing the partition plate340, and thus a flow supplying the source gas from the tip portion of the fluid discharge holes330toward the base portion of the fluid discharge holes330can be formed. In contrast, a part of the source gas introduced from the fluid introduction passage320and having reached the fluid flow area312reaches the fluid discharge area311from the distribution holes342in the middle of going through the fluid flow area312from the base portion toward the tip portion of the nozzle30, and is discharged therefrom.

When supplying the source gas from the nozzle30, although the inside of the process chamber is generally set at a high temperature, because the fluid discharge holes330are formed in the lower surface of the tubular part300of the nozzle30, and because the fluid discharge holes330are covered with the partition plate340, the heat transferred into the tubular passage310of the nozzle30through the fluid discharge holes330are blocked by the partition plate340, thereby preventing the source gas in the fluid flow area342from being directly heated by the heat. Accordingly, the source gas in the fluid flow area342can reach the tip portion of the tubular passage310without the self-decomposition, and a flow of the source gas sequentially discharged from the fluid discharge holes330of the tip portion of the tubular passage310can be formed. As discussed above, because the source gas reaching the fluid discharge area311from the distribution holes342is also present, two flows of the supply of the source gas from the fluid discharge holes330of the base portion of the nozzle30and the supply of the source gas from the fluid discharge holes330of the tip portion can be formed simultaneously, and thus the supply of the source gas can be made uniform in the lengthwise direction of the nozzle30.

Moreover, by variously changing the dimension and the arrangement of the distribution holes340of the partition plate340depending on the intended purpose, the distribution of the discharge rate of the source gas between the tip side and the base side of the nozzle30, the pressure and its distribution in the tubular passage310, the temperature and its distribution in the tubular passage310and the like can be variously adjusted. For example, the distance between the distribution holes342may be increased with the increasing distance from the base of the nozzle.

The partition plate340is preferred not to have the distribution hole342in a junction of the fluid introduction passage320and the partition plate340, and the partition part341is preferably configured to be continuously connected to the inner surface of the fluid introduction passage320. This is because the adjustment of the supply balance of the source gas in the lengthwise direction of the nozzle30becomes easier by temporarily holding the source gas introduced from the fluid introduction passage320and then supplying the source gas to the base portion of the nozzle30by way of the adjustable distribution holes342, since the supplied amount of the source gas is basically likely to be more at the base portion than at the tip portion.

Although the partition plate340may be arranged in a variety of forms, the partition plate340is preferably arranged so as to be parallel to the fluid discharge surface331when the fluid discharge surface331in which the fluid discharge holes330are formed has a flat surface. On the other hand, when the fluid discharge surface331has a curved surface, the partition plate340is preferably symmetrically arranged with respect to the fluid discharge holes330. This allows the fluid discharge area311and the fluid flow area312to be symmetrically arranged with respect to the fluid discharge holes330, which makes it possible to uniformly supply the source gas.

Here, although the above example has been described by citing an example of applying the nozzle30of the embodiment to the source gas supply nozzle of the film deposition apparatus, the nozzle30of the present embodiment can be applied to the fluid including a liquid as well as the gas.

The partition plate340may be referred to as a baffle plate or a baffle because the partition plate340is a plate for blocking the flow of the fluid and adjusting the flow of the fluid.

The fluid introduction passage320is a flow passage for introducing a fluid to the tubular passage310in the nozzle30from a fluid supply source, and is connected to the fluid flow area312of the tubular passage310. Hence, the fluid introduction passage320preferably has the same cross section as that of the fluid flow area312, but the fluid introduction passage320may be configured in a variety of forms as long as the fluid introduction passage320is in communication with the fluid flow area312.

The tubular part300including the fluid discharge holes330and the fluid introduction passage320are preferred to be configured in an integrated fashion. Although the partition plate340can be formed as a separate component from the tubular part300and can be bonded to or attached to the inside of the tubular passage310so as to be fixed thereto, the tubular part330and the fluid introduction passage320is preferred to be configured in a unified manner from the beginning so as not to generate a gap and the like between the partition plate340and the inner surface of the fluid introduction passage320. Although a material for these components can be selected from a variety of materials depending on the intended purpose, for example, quartz can be selected therefrom. Because quartz is often used in the nozzle of the substrate processing apparatus such as the film deposition apparatus, the entire nozzle30may be formed of quartz in an integrated fashion when the nozzle30is used for the substrate processing apparatus.

FIG. 2is a transparent perspective view illustrating an example of a configuration of the nozzle30of an embodiment of the present invention. Although the nozzle30illustrated inFIG. 2has components similar to those of the nozzle30described inFIG. 1,FIG. 2depicts parts of the nozzle30simplified inFIG. 1in more detail. Here,FIG. 2illustrates the tip portion of the nozzle30.

As illustrated inFIG. 2, the fluid discharge holes330may be provided in the width direction as well as the lengthwise direction of the nozzle30. This causes the plurality of lines of the fluid discharge holes330arranged along the lengthwise direction of the nozzle30to be arranged in the width direction, which makes it possible to uniformly discharge and supply a fluid even in the width direction of the nozzle30. Moreover, as illustrated inFIG. 2, the fluid discharge holes330adjacent to each other in the width direction of the nozzle30may be arranged at different positions in the lengthwise direction (orthogonal projection projected in the lengthwise direction).FIG. 2illustrates an example of four lines of the fluid discharge holes330arranged at predetermined intervals in the lengthwise direction. InFIG. 2, the arrangement of the fluid discharge holes330in each of the lines are shifted from each other in the lengthwise direction, and many orthogonally-disposed rows composed of four of the fluid discharge holes330are formed in the width direction and are orthogonally arranged in parallel to each other. In this manner, the lines of the fluid discharge holes330arranged at predetermined intervals along the lengthwise direction may be arranged at different positions in the lengthwise direction so as to be shifted from each other in the lengthwise direction in order to uniformly cover the whole area both in the lengthwise direction and in the width direction. This enables the fluid to be supplied uniformly.

Here, as illustrated inFIG. 2, the fluid discharge holes330are formed into small columnar holes so as to penetrate through the lower surface of the tubular part310with high density so as to uniformly cover the lower surface of the tubular part310. Although the number of the fluid discharge holes330may change variously depending on the intended purpose, as illustrated inFIG. 2, the fluid discharge holes330are preferred to be formed with the high density enough to uniformly cover the fluid discharge surface331. For example, when the nozzle30is configured to have a length of about 50 cm, about seven hundreds of the fluid discharge holes330may be formed.

As illustrated inFIG. 2, the partition plate340may be provided to have a plate-like shape such that the end thereof is connected to the side surface of the inner surface of the tubular passage310, and to extend along the lengthwise direction of the nozzle30. The partition plate340extends in the lengthwise direction so as to partition the tubular passage310into the fluid discharge area311and the fluid flow area312along the lengthwise direction, and causes the fluid discharge area311to be in communication with the fluid flow area312through the distribution holes342provided in midstream. The distribution holes342have a diameter much larger than that of the fluid discharge holes330, and large enough to include the plurality of fluid discharge holes330. The distribution holes342have the same width as that of the partition part341, and only a single distribution hole342is formed in the width direction, which differs from the fluid discharge holes330in that the plurality of fluid discharge holes330can be formed in the width direction. However, the plurality of distribution holes342can be formed in the width direction depending on the intended purpose.

In addition, the distance between the adjacent distribution holes342is much larger than that of the fluid discharge holes330. The distribution holes342equal to or less than ten are formed in the partition plate340when the nozzle30has the length of 50 cm as discussed above. For example, about seven distribution holes342may be formed in the partition plate340. Here, inFIG. 2, although the distribution holes342are formed to have a shape similar to an ellipse as a whole like combining a rectangle extending along the lengthwise direction of the nozzle30and a circle, the distribution holes342may be formed into a variety of shapes depending on the intended purpose.

The folded passage313is formed in the tip of the tubular passage310, and the tip of the tubular passage310may have a curved inner surface by processing the inner surface of the tubular passage310so as to form the curved inner surface. This allows the fluid to smoothly return from the tip by flowing through the folded passage313.

Thus, the nozzle30of the embodiment can be configured to have a variety of shapes as long as the nozzle30includes the partition plate340having the distribution holes342.

FIG. 3is a graph illustrating an example of discharge distribution of a source gas required for a source gas nozzle of a film deposition apparatus. InFIG. 3, a letter “N” in the transverse axis indicates a base portion of a nozzle and letters “AN” indicate a tip portion of the nozzle. The longitudinal axis indicates distribution of a source gas discharge rate and film thickness distribution of a deposited film. When depositing a film on a wafer having an interconnection pattern such as a trench and a via-hole formed in a surface of the wafer, a characteristic curve G expressed by a solid line inFIG. 3is known as a preferable distribution characteristic curve. More specifically, when the characteristic curve G has a peak at a point slightly closer to the tip portion than the center; the source gas discharge rate approximately symmetrically decreases with respect to the peak; and the flow rate distribution curve becomes convex upward so that the source gas discharge flow rate is the lowest at the base portion of the nozzle, uniformity of the film thickness becomes the most preferable as expressed by a dashed line.

Accordingly, when the characteristic curve G expressed by the solid line inFIG. 3is reproduced by measuring the discharge flow rate of the nozzle, the nozzle that can achieve the preferable film thickness uniformity, can be implemented.

FIG. 4is a graph showing a simulation result when simulating the nozzle30of the embodiment of the present invention. InFIG. 4, dots “A” show discharge flow rate distribution when supplying N2gas at a flow rate of 300 sccm by using the nozzle30of the embodiment, and dots “B” show discharge flow rate distribution when supplying Ar gas at a flow rate of 1000 sccm by using the nozzle30of the embodiment. Moreover, as a comparative example, dots “C” show discharge flow rate distribution when supplying N2gas at a flow rate of 300 sccm by using a conventional nozzle without the partition plate340, and dots “D” show discharge flow rate distribution when supplying Ar gas at a flow rate of 1000 sccm by using the conventional nozzle without the partition plate340.

As illustrated inFIG. 4, the dots A and the dots B using the nozzle30of the embodiment have the distribution similar to the characteristic curve G inFIG. 3. In contrast, the dots C and the dots D have the distribution having high values on the left side and low values on the right side, which is greatly different from the characteristic curve G.

Accordingly, this simulation result indicates that the nozzle30of the embodiment is a nozzle that can implement the film deposition having the excellent film thickness uniformity across the surface of a wafer. Thus, according to the nozzle30of the embodiment, by providing the partition plate340having the adjustable distribution holes342in the tubular passage310inside the tubular part300, the discharge flow rate distribution of a fluid can be set at desired distribution, and the fluid can be discharged and supplied at the discharge flow rate distribution appropriate for a variety of substrate processes.

Next, a description is given below of a substrate processing apparatus according to an embodiment to which the nozzle30of the embodiment of the present invention is applied, with reference toFIGS. 5 through 9. Here, the substrate processing apparatus according to the embodiment of the present invention is described by citing an example of a turntable type (described later) substrate processing apparatus using a susceptor that is configured to be a film deposition apparatus performing the film deposition on surfaces of a plurality of substrates by supplying a fluid to a predetermined supply area. However, the susceptor does not have to be the turntable type, and the substrate process does not have to be the film deposition. The substrate processing apparatus of the embodiment can be applied to a variety of substrate processing apparatuses using a nozzle.

Here,FIG. 5is a cross-sectional view of the substrate processing apparatus taken along line I-I′ ofFIG. 7.FIGS. 6 and 7are diagrams used to describe an exemplary internal structure of a process chamber1(described later) of the substrate processing apparatus. InFIGS. 6 and 7, a top plate11(described later) is omitted for convenience of explanation.

FIG. 8is a cross-sectional view of apart of the process chamber1from a process gas nozzle30(described later) to a process gas nozzle32taken along a concentric circle of a susceptor2(described later).FIG. 9is a partial cross-sectional view illustrating an area where a ceiling surface44(described later) is provided. The process gas nozzle30has a configuration similar to the nozzle30of the embodiment of the present invention, and is the nozzle30including the partition plate340having the distribution holes342inside the tubular passage310.

As illustrated inFIGS. 5 through 7, the substrate processing apparatus according to the embodiment of the present invention includes the process chamber1having a substantially circular shape in a plan view and a flat shape in a side view, the susceptor2disposed in the process chamber1, and a control unit (controller)100for controlling operations of the entire substrate processing apparatus (e.g., the control unit100controls a timing of supplying gases from process gas nozzles30and32).

The process chamber1includes a chamber body12formed into a closed-end cylinder and a top plate11that is placed on the chamber body12and detachable from the chamber body12. The top plate11is attached to the chamber body12via a sealing member13(seeFIG. 5) such as an O-ring and hermetically seals the process chamber1.

The susceptor2is fixed to a cylindrical core part21housed in a case body20such that the center of the process chamber1coincides with the center of rotation of the susceptor2. The susceptor2has holding areas in its upper surface to receive a plurality of substrates (which are hereafter referred to as “wafers W”).

The case body20is a cylindrical case having an opening at its upper end. A flange at the upper end of the case body20is hermetically attached to a lower surface of a bottom part14of the process chamber1. The case body20isolates the internal atmosphere of the process chamber1from the external atmosphere.

The core part21is fixed to an upper end of a rotational shaft22that extends in the vertical direction. The rotational shaft22penetrates through the bottom part14of the process chamber1. A lower end of the rotational shaft22is attached to a drive unit23that rotates the rotational shaft22about a vertical axis. The rotational shaft22and the drive unit23are housed in the case body20.

As illustrated inFIG. 7, multiple (five in the present embodiment) recesses24for holding the wafers W (substrate holding areas) are formed in the upper surface of the susceptor2. The recesses24have a substantially circular shape and are arranged along the rotational direction (or the circumferential direction) of the susceptor2. InFIG. 7, for convenience sake, only one wafer W placed in one of the recesses24is illustrated. The number of wafers W that the susceptor2can hold is not limited to five. The susceptor2that can be used in the embodiment of the present invention may instead be configured to hold four or less wafers W or six or more wafers W.

In the present embodiment, each of the recesses24has an inside diameter (e.g., 4 mm greater than the diameter of the wafer W) that is slightly greater than the diameter (e.g., 300 mm) of the wafer W. The depth of each of the recesses24is substantially the same as the thickness of the wafer W. This causes the height of the upper surfaces of the wafers W placed in the recesses24to become substantially the same as the height of the upper surface (where the wafers W are not placed) of the susceptor2.

In the substrate processing apparatus of the present embodiment, the process gas nozzle30is a first gas supply part and is disposed in a first process area (described later) above the susceptor2. As discussed above, the process gas nozzle30is the nozzle of the embodiment described above, and is used as the process gas nozzle30for supplying a source gas in the substrate processing apparatus of the present embodiment. The process gas nozzle32is a second gas supply part and is disposed in a second process area (described later) that is apart from the first process area in the circumferential direction of the susceptor2. Separation gas nozzles41and42are separation gas supply parts and are disposed between the first process area and the second process area. For example, the nozzles30,32,41, and42may be made of quartz.

More specifically, as illustrated inFIGS. 6 and 7, the process gas nozzle32, the separation gas nozzle41, the process gas nozzle30, and the separation gas nozzle42are arranged clockwise (along the rotational direction of the susceptor2) in this order from a transfer opening15for transferring the wafers W. In other words, the process gas nozzle32, the separation gas nozzle41, the process gas nozzle30, and the separation gas nozzle42are arranged at intervals along the circumferential direction of the process chamber1. Gas introduction ports30a,32a,41aand42a, which are outer ends of the gas nozzles30,32,41and42, are fixed to the outer peripheral wall of the chamber body12. The gas nozzles30,32,41and42are inserted through the outer peripheral wall of the chamber body12into the process chamber1. In the process chamber1, the gas nozzles30,32,41and42extend parallel to the upper surface of the susceptor2in the radial direction of the chamber body12toward the center of rotation of the susceptor2.

Multiple gas discharge holes (seeFIG. 8) facing the susceptor2are formed in the lower surface of each of the process gas nozzles30and32. For example, the gas discharge holes may be arranged at 10-mm intervals in the lengthwise direction of the corresponding process gas nozzle30or32. An area below the process gas nozzle30functions as an area for causing a first process gas to adsorb on a wafer W (which is hereinafter referred to as a “first process area P1”). An area below the process gas nozzle32functions as an area for causing a second gas to react with the first process gas adsorbed on the wafer W so as to deposit a reaction product of the first process gas and the second process gas (which is hereinafter referred to as a “second process area P2”). Here, for example, a source gas such as an organometallic gas used for depositing a high dielectric film (high-k film) may be used as the first process gas, and for example, tris(dimethylamino)cyclopentadienylzirconium (C11H23N3Zr) and the like are available for the first process gas. A reaction gas such as an oxidation gas (e.g., O2gas or O3gas), a nitriding gas (e.g., NH3gas) or the like may be used as the second process gas. In general, the self-decomposition often occurs in supplying a source gas composed of a organometallic gas when depositing a high dielectric film, using the process gas nozzle30of the embodiment when depositing the high-k film is highly effective. However, the first process gas is not limited to the above-mentioned gas, and a variety of gases can be used.

The process gas nozzle32is disposed in the second process area P2that is zoned above the upper surface of the susceptor2. The process gas nozzle32is connected to a gas supply source (not shown) for supplying the second process gas via a pipe and the like (not shown). Thus, the process gas nozzle32supplies the second process gas to the upper surface of the susceptor2. In the present embodiment, the process gas nozzle32supplies the second process gas into the process chamber1(the second process area P2) by complementarily opening and closing valves (not shown).

Each of the separation gas nozzles41and42is disposed between the first process area P1and the second process area P2that are provided apart from each other in the circumferential direction of the susceptor2. Each of the separation gas nozzles41and42is connected to a gas supply source (not shown) for supplying a separation gas via a pipe and the like (not shown). Thus, the separation gas nozzles41and42supply the separation gas to the upper surface of the susceptor2.

The substrate processing apparatus of the present embodiment can use a variety of reaction gases reactable with the first process gas as the second process gas, but may use, for example, an oxygen-containing gas as the second process gas. The oxygen-containing gas is, for example, oxygen gas or ozone gas. The first process gas supplied from the process gas nozzle30and adsorbed on the substrate is oxidized by the second process gas supplied from the process gas nozzle32, thereby generating an oxidation product.

In the present embodiment, the substrate processing apparatus uses an inert gas as the separation gas. Examples of the inert gas include a noble gas such as argon (Ar) gas and helium gas, and nitrogen gas. The separation gas is used as a purge gas for purging the wafer W. In the present embodiment, a description is given below of an example of using N2gas, which is generally used as the purge gas, as the separation gas.

As illustrated inFIGS. 6 and 7, two convex portions4are provided in the process chamber1of the substrate processing apparatus. In a plan view, each convex portion4has an approximately sectorial shape whose top part is cut off to form an arc (inner arc). In the present embodiment, the inner arc of the convex portion4is connected to a protruding portion5. The convex portion4is disposed such that its outer arc (which is at an end of the convex portion4opposite to the inner arc) becomes substantially parallel to the inner circumferential surface of the chamber body12of the process chamber1.

More specifically, as illustrated inFIG. 8, the convex portions4are attached to the lower surface of the top plate11. The convex portion4includes a flat lower surface that is referred to as a ceiling surface44(first ceiling surface). Parts of the lower surface of the top plate11on both sides of the ceiling surface44in the circumferential direction are referred to as ceiling surfaces45(second ceiling surfaces). The ceiling surfaces45are higher than the ceiling surface44. Thus, the convex portion4forms a narrow separation space(s) H and spaces481and482, into which gas flows from the separation space H, in the process chamber1. In other words, the convex portions4form narrow separation spaces H that function as separation areas D illustrated inFIG. 6.

Also, as illustrated inFIG. 8, a groove43is formed in the middle in the circumferential direction of the convex portion4. The groove43extends in the radial direction of the susceptor2. The separation gas nozzle42is placed in the groove43of one of the convex portions4, and the separation gas nozzle41is placed in the groove43of the other one of the convex portions4.

Here, gas discharge holes42hare formed in a lower surface of the separation gas nozzle42, which faces the susceptor2. The gas discharge holes42hare arranged at predetermined intervals (e.g., 10-mm intervals) in the lengthwise direction of the separation gas nozzle42. The opening diameter of each of the gas discharge holes42his, for example, from about 0.3 mm to about 1.0 mm. Although not illustrated in the drawings, gas discharge holes are also formed in the separation gas nozzle41in a similar manner.

Furthermore, as illustrated inFIG. 8, the process gas nozzles30and32are disposed in spaces below the higher ceiling surfaces45. The process gas nozzles30and32are positioned apart from the ceiling surfaces45and close to the wafer W or the upper surface of the susceptor2. Here, as illustrated inFIG. 8, the process gas nozzle30is disposed in the space481(space below the higher ceiling surface45), and the process gas nozzle32is disposed in the space482(space below the higher ceiling surface45).

The narrow separation space H is formed between the lower ceiling surface44and the upper surface of the susceptor2. When an inert gas (e.g., N2gas) is supplied from the separation gas nozzle42, the inert gas flows into the spaces481and482through the separation space H. Because the volume of the separation space H is smaller than the volumes of the spaces481and482, the pressure in the separation space H where the inert gas is supplied becomes higher than the pressures in the spaces481and482. Thus, the separation space H provides a pressure barrier between the spaces481and482.

Furthermore, the flow of the inert gas from the separation space H into the spaces481and482functions as a counter flow to the first process gas in the first process area P1and the second process gas in the second process area P2. Accordingly, the substrate processing apparatus of the present embodiment is configured to separate the first process gas in the first process area P1from the second process gas in the second process area P2by using the separation space H. In other words, the substrate processing apparatus is configured to prevent the first process gas from mixing and reacting with the second process gas in the process chamber1.

A height h1of the ceiling surface44from the upper surface of the susceptor2can be determined based on the pressure in the process chamber1during a film deposition process, the rotational speed of the susceptor2, and/or the amount of the supplied separation gas (N2gas) so that the pressure in the separation space H becomes higher than the pressures in the spaces481and482. The height h1of the ceiling surface44from the upper surface of the susceptor2can be also determined based on the specifications of the substrate processing apparatus and types of supplied gases. Furthermore, the height h1of the ceiling surface44from the upper surface of the susceptor2can be determined in advance by experiments or calculations.

As illustrated inFIGS. 6 and 7, the protruding portion5is provided on the lower surface of the top plate11to surround the core part21to which the susceptor2is fixed. The protruding portion5is connected to the center-side ends (inner arcs) of the convex portions4. The lower surface of the protruding portion5is formed to have the same height as the ceiling surface44.

As illustrated inFIG. 6, an L-shaped bent portion46is formed at the outer end of the convex portion4(i.e., an end that is closer to the inner circumferential surface of the vacuum chamber1). The bent portion46faces the outer end surface of the susceptor2. The bent portion46prevents gases from flowing between the space481and the space482through a gap between the susceptor2and the inner circumferential surface of the chamber body12. The sectorial convex portion4is provided on the lower surface of the top plate11.

A small gap is provided between the outer surface of the bent portion46and the chamber body12so that the top plate11can be detached from the chamber body12. For example, the gap between the inner surface of the bent portion46and the outer end surface of the susceptor2and the gap between the outer surface of the bent portion46and the chamber body12can be set at a value that is substantially the same as the height of the ceiling surface44from the upper surface of the susceptor2.

Referring toFIG. 7again, a first evacuation port610in communication with the space481(FIG. 8) and a second evacuation port620in communication with the space482(FIG. 8) are formed between the susceptor2and the inner circumferential surface of the chamber body12. As illustrated inFIG. 5, each of the first evacuation port610and the second evacuation port620is connected to an evacuation unit (e.g., a vacuum pump640) via an evacuation pipe630. Here, a pressure controller650may be provided in the evacuation pipe630between each of the first and second evacuation ports610and620and the vacuum pump640.

As illustrated inFIGS. 5 and 9, a heater unit7is provided in a space between the susceptor2and the bottom part14of the vacuum chamber1. The heater unit7heats, via the susceptor2, the wafers W on the susceptor2to a temperature (e.g., 450° C.) specified by a process recipe. A ring-shaped cover member71is provided below the outer periphery of the susceptor2. The cover member71prevents entry of gases into a space below the susceptor2.

As illustrated inFIG. 9, the cover member71includes an inner member71aand an outer member71b. The inner member71ais provided below the susceptor2and spans an area that corresponds to the outer periphery of the susceptor2and a narrow space surrounding the outer circumference of the susceptor2. The outer member71bis provided between the inner member71aand the inner circumferential surface of the vacuum chamber1. The outer member71bis disposed below the bent portion46formed at the outer end of the convex portion4such that a small gap is formed between the outer member71band the lower end of the bent portion46. The inner member71asurrounds the heater unit7.

The control unit100illustrated inFIG. 5sends commands (or signals) to other components of the substrate processing apparatus, thereby controlling operations of the components. The control unit100may be constituted of a computer or an arithmetic processing unit for controlling operations of the entire substrate processing apparatus. For example, the control unit100executes a program stored in a memory unit101to control hardware components of the substrate processing apparatus, thereby depositing a film on the surfaces of the plurality of wafers W. The control unit100may include a central processing unit (CPU) and a memory (e.g., ROM or RAM).

More specifically, the memory of the control unit100may store a program for causing the substrate processing apparatus (or the CPU) to perform a substrate process described later. The program may include code units corresponding to steps to be performed in the substrate process. The control unit100reads the program from a storage medium102(e.g., a hard disk, a compact disk, a magneto-optical disk, a memory card, or a flexible disk), stores the program in the memory unit101, and then installs or loads the program into the control unit100.

Next, a description is given below of a procedure to perform a film deposition process by using the substrate processing apparatus described above.

To begin with, a wafer W is placed on each of the plurality of recesses24provided in the upper surface of the susceptor2. More specifically, a gate valve (not illustrated in the drawings) is opened, and the wafer W is transferred into the recess24of the susceptor2through the transfer opening15by using the transfer arm10(seeFIG. 7). When the recess24stops at a position facing the transfer opening15, the wafer W may be transferred into the recess24by moving lift pins (not illustrated in the drawings) up and down from the bottom side of the process chamber1via through holes formed in the bottom of the recess24. Moreover, the wafer W is placed on each of the plurality of (five, in the present embodiment) recesses24of the susceptor2by intermittently rotating the susceptor2.

Next, after the inside of the process chamber1is set at a predetermined pressure, a separation gas is supplied into the process chamber1. More specifically, after closing the gate valve and evacuating the process chamber1to the lowest ultimate vacuum by using the vacuum pump640, the separation gas (e.g., N2gas) is supplied into the process chamber1from the separation gas nozzles41and42at a predetermined flow rate. At this time, the separation gas is also supplied from the separation gas supply pipe51and the purge gas supply pipes72and73(seeFIGS. 5 and 9) at a predetermined flow rate. Furthermore, the pressure inside the process chamber1can be adjusted to a preliminarily set process pressure by using the pressure controller650. Next, the wafers W are heated by using the heater unit7while rotating the susceptor2, for example, in a clockwise fashion.

Subsequently, the first process gas nozzle30and the second process gas nozzle32start supplying process gases. The wafers W are processed by starting the supply of a first process gas and a second process gas. A source gas is supplied from the first process gas nozzle30in the first process area P1and adsorbs on surfaces of the wafers W, and a reaction gas reactable with the source gas adsorbed on the wafers W is supplied from the second process gas nozzle32in the second process area P2. Then, a reaction product of the source gas and the reaction gas deposits on the wafers W, and a molecular layer made of the reaction product deposits on the wafers W. Here, the wafers W periodically pass through the first process area P1, the separation area D, the second process area P2and the separation area D by the rotation of the susceptor2, and a film deposits on the wafers W for each rotation of the susceptor2. Even when a source gas for depositing a high dielectric film is supplied from the first process gas nozzle30, the source gas is not decomposed by the self-decomposition and is discharged and supplied at the discharge flow rate distribution described inFIGS. 3 and 4. A high dielectric film is deposited with a high degree of film thickness uniformity across the surface of the wafer W. When the deposited film reaches a predetermined film thickness, the first process gas nozzle30stops supplying the source gas that is the first process gas, and the second process gas nozzle32continues to supply the oxidation gas or the nitriding gas as necessary, thereby treating the4film. Here, the treatment is not performed if unnecessary, and the supply of the first process gas and the second process gas may stop at the same time.

After finishing the supply of the process gases from the first process gas nozzle30and the second process gas nozzle32, the wafers W are carried out of the process chamber1by a reverse procedure to the carry-in procedure. More specifically, the gate valve (not illustrated in the drawings) is opened, and the wafers W on which the film is deposited are carried out of the process chamber1through the transfer opening15by using the transfer arm10(seeFIG. 7). The wafers W are carried out by using the lift pins (not illustrated in the drawings).

As discussed above, the film deposition process is performed. Because the source gas is supplied at the desired flow rate distribution without being decomposed by the self-decomposition, the film deposition can be performed while keeping the high uniformity of film thickness across the surface of the wafer, thereby depositing a high-quality film.

Moreover, the substrate processing apparatus may be a substrate processing apparatus that performs not only the film deposition process but also a variety of substrate processes, and the nozzle of the embodiment can be applied not only to the gas but also a fluid such as a liquid or the like. In this case, because an ideal discharge flow rate distribution differs depending on a type of a process, a nozzle structure relating to the partition plate340and the distribution holes342, and process conditions such as a temperature and a pressure in the process chamber may be properly adjusted so as to have the proper flow rate distribution for each process. Because the nozzle30of the embodiment can adjust a dimension, the arrangement and the like of the distribution holes342of the partition plate340in a variety of forms, the nozzle30can adjust to the variety of conditions flexibly and properly. In addition, although the description has been given by citing an example of the nozzle30being used as the source gas nozzle, because a type of a gas is not limited, applying the nozzle30to the reaction gas such as the oxidation gas and the nitriding gas is also possible.

According to the embodiments of the present invention, a source gas can be supplied in a preferable condition.