Substrate processing apparatus and deposition method

Abstract

To provide a technique that can precisely deposit films on substrates.SOLUTION: A substrate processing apparatus includes: a processing container; a raw material gas supply section that supplies raw material gas to the inside of the processing container; a reaction gas supply section that supplies reaction gas that reacts with the raw material gas to the inside of the processing container; and a dehydration gas supply section that supplies dehydration gas to the inside of the processing container to desorb moisture. Inside the processing container, in a state of housing a substrate, the raw material gas is supplied to the substrate, and thereafter, the reaction gas and dehydration gas are supplied to the substrate. This allows the substrate processing apparatus to precisely deposit films on the substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus and a film forming method. [Background technology]

[0002] Patent Document 1 discloses a substrate processing apparatus that supplies a source gas and a reactive gas (ozone gas) while rotating a turntable on which multiple substrates are placed, to form a film on each substrate. In this type of substrate processing apparatus, after the source gas is supplied and adsorbed on the substrate, moisture (H2O) is generated by an oxidation reaction of the reactive gas in the process of supplying the reactive gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-21888 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for forming a film on a substrate with high accuracy. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a substrate processing apparatus including a processing vessel, a raw material gas supply unit that supplies a raw material gas into the processing vessel, a reactive gas supply unit that supplies a reactive gas that reacts with the raw material gas into the processing vessel, and a dehydration gas supply unit that supplies a dehydration gas into the processing vessel to desorb moisture, wherein, with a substrate accommodated inside the processing vessel, the raw material gas is supplied to the substrate, and then the reactive gas and the dehydration gas are supplied to the substrate. Effect of the Invention

[0006] According to one aspect, a film can be formed on a substrate with high precision. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view illustrating a substrate processing apparatus according to an embodiment of the present invention. [Diagram 2] 2 is a plan view illustrating an outline of the inside of a processing container of the substrate processing apparatus; FIG. [Diagram 3] 1 is a partial cross-sectional view of a processing vessel along the concentric circles of a rotary table from a raw material gas nozzle, a dehydration gas nozzle, and a separation gas nozzle. [Figure 4] 4 is an explanatory diagram showing the movement of molecules on a substrate in a reactive gas processing space. FIG. [Diagram 5] 4 is an explanatory diagram showing the movement of molecules on a substrate in a second separation space and a source gas processing space. FIG. [Figure 6] 4 is a flowchart showing a film forming method in the substrate processing apparatus according to the embodiment. [Figure 7] 11 is a table comparing the film thickness in a film formation process in the case where ethanol is supplied and the film thickness in a film formation process in the case where ethanol is not supplied. [Figure 8] 10 is a flowchart showing a film forming method according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0009] Fig. 1 is a cross-sectional view that illustrates a substrate processing apparatus 100 according to an embodiment. Fig. 2 is a plan view that illustrates an interior of a processing vessel 1 of the substrate processing apparatus 100. As illustrated in Figs. 1 and 2, the substrate processing apparatus 100 according to the embodiment is a film formation apparatus that forms a film on a surface of a substrate W by atomic layer deposition (ALD) or molecular layer deposition (MLD). The substrate processing apparatus 100 includes a processing vessel 1 that accommodates a substrate W therein and performs a film formation process, and a turntable 2 that is rotatably provided within the processing vessel 1.

[0010] The processing vessel 1 is formed in a flat cylindrical shape and has a processing chamber therein for accommodating a substrate W. For example, the processing vessel 1 is configured by assembling a vessel body 12 having an open top and a top plate 11 disposed on the upper part of the vessel body 12. For convenience of explanation, the top plate 11 is not shown in FIG. 2. The vessel body 12 has a disk-shaped bottom 14 and a side portion 13 protruding vertically upward from the outer edge of the bottom portion 14. The side portion 13 of the vessel body 12 and the top plate 11 are fixed airtight via a seal member 15 such as an O-ring.

[0011] The turntable 2 is formed in an annular shape, and its inner periphery is fixed to a cylindrical core part 21. The core part 21 is fixed to the upper end of a rotation shaft 22 extending in the vertical direction. The rotation shaft 22 penetrates the bottom part 14 of the processing vessel 1, and its lower end is held by a driving part 23. The driving part 23 rotates the rotation shaft 22 about its axis. As a result, the turntable 2 rotates via the rotation shaft 22 and the core part 21, with the center of the processing vessel 1 as the center of rotation.

[0012] The rotating shaft 22 and the driving unit 23 are housed in a cylindrical case body 20 that is open at the top. The case body 20 has a flange portion at the upper end, and is airtightly fixed to the bottom portion 14 of the processing vessel 1. Therefore, the internal space of the case body 20 is isolated from the outside of the case body 20 and is in communication with the processing chamber of the processing vessel 1.

[0013] 2, a plurality of (six in FIG. 2) circular recesses 24 (mounting portions) on which the substrate W can be mounted are provided on the upper surface of the turntable 2 along the rotation direction of the turntable 2. The substrate W to be subjected to the film formation process may be a semiconductor wafer such as a silicon semiconductor, a compound semiconductor, or an oxide semiconductor. The substrate W may have a pattern such as a trench or a via.

[0014] The recess 24 has an inner diameter slightly larger than the diameter (e.g., 300 mm) of the substrate W, and a depth approximately equal to the thickness of the substrate W. As a result, when the substrate W is placed in the recess 24, the upper surface of the substrate W and the upper surface of the turntable 2 (the area on which the substrate W is not placed) are approximately at the same height.

[0015] The substrate processing apparatus 100 includes a gas supply unit 30 for supplying gas into the processing vessel 1. The gas supply unit 30 includes a plurality of gas nozzles 30N formed of, for example, quartz and extending linearly. Each gas nozzle 30N has an inlet port 30a, which is a base end, fixed to a side portion 13 of the processing vessel 1, and extends radially inside the processing vessel 1 to near the center. Each gas nozzle 30N extends parallel to the upper surface of the turntable 2 inside the processing vessel 1. Each gas nozzle 30N has a plurality of gas discharge holes 30h that open vertically downward toward the turntable 2 (see also FIG. 3). Each gas discharge hole 30h is arranged at equal intervals along the axial direction (the radial direction of the processing vessel 1).

[0016] The gas supply unit 30 includes a raw material gas supply unit 31 that supplies a raw material gas, a reactive gas supply unit 32 that supplies a reactive gas, a dehydration gas supply unit 33 that supplies a dehydration gas, and a separation gas supply unit 34 that supplies a separation gas. The raw material gas supply unit 31 has two raw material gas nozzles 31N as the gas nozzles 30N. The reactive gas supply unit 32 has four reactive gas nozzles 32N as the gas nozzles 30N. The dehydration gas supply unit 33 has one dehydration gas nozzle 33N as the gas nozzles 30N. The separation gas supply unit 34 has one separation gas nozzle 34N as the gas nozzles 30N. The processing vessel 1 in the illustrated example has three reactive gas nozzles 32N, one separation gas nozzle 34N, two raw material gas nozzles 31N, one dehydration gas nozzle 33N, and one reactive gas nozzle 32N arranged in this order clockwise from the transfer port 16 provided in the side portion 13.

[0017] The raw material gas supply unit 31 connects a raw material gas supply path 41 to the inlet port 30a of each raw material gas nozzle 31N protruding to the outside of the processing vessel 1. The raw material gas supply unit 31 includes a raw material gas supply source 411, an opening / closing valve 412, a flow rate regulator 413, and the like on the raw material gas supply path 41.

[0018] The source gas supplied by the source gas supply unit 31 may be an appropriate gas containing a metal element or a semiconductor element. For example, the source gas is a gas for forming a high-k (high dielectric) film, and may be a gas containing an organic metal or a semiconductor containing a metal element or a semiconductor element. For example, the metal element may be aluminum (Al), zirconium (Zr), hafnium (Hf), etc., and the semiconductor element may be silicon (Si), etc. In this embodiment, the source gas is a gas containing zirconium. The source gas is preferably a gas that has adsorptivity to the surface of the substrate W.

[0019] The reactive gas supply unit 32 connects a reactive gas supply path 42 to the inlet port 30a of each reactive gas nozzle 32N protruding to the outside of the processing chamber 1. The reactive gas supply unit 32 includes a reactive gas supply source 421, an opening / closing valve 422, a flow rate regulator 423, and the like on the reactive gas supply path 42.

[0020] The reactive gas supplied by the reactive gas supply unit 32 is selected to be an oxidizing gas that reacts with the source gas adsorbed on the surface of the substrate W to generate an oxide. In this embodiment, the reactive gas is a gas containing ozone (O3) (for example, a mixture of oxygen (O2) gas and ozone gas). Therefore, the reactive gas supply source 421 may be an ozonizer.

[0021] The dehydration gas supply unit 33 connects a dehydration gas supply path 43 to an inlet port 30a of a dehydration gas nozzle 33N protruding to the outside of the processing vessel 1. The dehydration gas supply unit 33 includes a dehydration gas supply source 431, an opening / closing valve 432, a flow rate regulator 433, and the like on the dehydration gas supply path 43.

[0022] The dehydration gas selected is a gas that reacts with moisture (H2O) generated on the surface of the substrate W to desorb the moisture. In this embodiment, the dehydration gas is ethanol (EtOH) gas. The principle of moisture desorption by the dehydration gas will be described in detail later. In addition to the dehydration gas supply path 43, a separation gas supply path 44 of the separation gas supply unit 34 is also connected to the dehydration gas nozzle 33N. The separation gas supply path 44 is provided with a separation gas supply source 441, an opening / closing valve 442, a flow rate regulator 443, and the like.

[0023] The separation gas supply unit 34 connects a separation gas supply path 44 to an inlet port 30a of a separation gas nozzle 34N protruding to the outside of the processing vessel 1. The separation gas supply unit 34 includes a separation gas supply source 441, an opening / closing valve 442, a flow rate regulator 443, and the like on the separation gas supply path 44.

[0024] The separation gas supplied from the dehydration gas nozzle 33N and the separation gas nozzle 34N is appropriately selected from rare gases such as argon (Ar) and helium (He), and inert gases such as nitrogen (N2) gas, etc. In the embodiment, nitrogen gas is used as the separation gas.

[0025] The processing vessel 1 also includes an activation plate 80 above the two source gas nozzles 31N and above the three reactive gas nozzles 32N. Each activation plate 80 is formed in a substantially fan-shaped box in a plan view, and temporarily retains the supplied source gas or reactive gas. As a result, the activation plate 80 of each source gas nozzle 31N promotes the adsorption of the source gas. The activation plate 80 of the reactive gas nozzle 32N promotes the decomposition of the reactive gas (ozone gas) to activate the reactive gas. The activation plate 80 may include an activation means such as a catalyst, a laser, or a heater.

[0026] The processing vessel 1 also has two internal convex portions 4 arranged along the circumferential direction. The convex portions 4 have a generally sectorial planar shape with an apex cut into an arc shape. In the embodiment, the inner arc is connected to a protruding portion 5 described below, and the outer arc is disposed along the inner circumferential surface of a side portion 13 of the processing vessel 1.

[0027] 3 is a partial cross-sectional view of the processing vessel 1 along the concentric circle of the turntable 2 from the source gas nozzle 31N to the dehydration gas nozzle 33N and the separation gas nozzle 34N. As shown in FIG. 3, the convex portion 4 is attached to the lower surface of the top plate 11. Therefore, inside the processing vessel 1, there are a flat low ceiling surface 46 which is the lower surface of the convex portion 4, and ceiling surfaces 47 which are located on both sides of the ceiling surface 46 in the circumferential direction and are higher than the ceiling surface 46.

[0028] A groove 45 extending along the radial direction of the turntable 2 is formed in the convex portion 4. A dehydration gas nozzle 33N is housed in this groove 45. A similar groove 45 is formed in the other convex portion 4, and a separation gas nozzle 34N is housed in this groove 45 (see FIG. 2).

[0029] 3, a source gas nozzle 31N is provided in a space 481 (a space vertically below the high ceiling surface 47) on the right side of the convex portion 4. A reaction gas nozzle 32N is provided in a space 482 (a space vertically below the high ceiling surface 47) on the left side of the convex portion 4. These gas nozzles 30N are provided in the vicinity of the substrate W, spaced apart from the ceiling surface 47. The activation plate 80 described above is provided between the source gas nozzle 31N and the ceiling surface 47.

[0030] On the other hand, the low ceiling surface 46 forms a narrow space, separation space H, relative to the turntable 2. Since the volume of separation space H is smaller than the volumes of spaces 481 and 482, when separation gas is supplied from the dehydration gas nozzle 33N, the pressure in separation space H can be made higher than the pressures in spaces 481 and 482 by the separation gas. As a result, separation space H forms a pressure barrier between spaces 481 and 482. Moreover, the separation gas flowing out from separation space H to spaces 481 and 482 acts as a counterflow between the source gas and the reaction gas. Therefore, the source gas and the reaction gas are separated by separation space H, and are prevented from mixing with each other and reacting with each other.

[0031] 1 and 2, the protrusion 5 provided on the underside of the top plate 11 surrounds the outer periphery of the core portion 21 that fixes the rotary table 2. This protrusion 5 is continuous with the part of the convex portion 4 on the rotation center side, and its underside is formed at the same height as the ceiling surface 46.

[0032] Further, exhaust ports 61 are formed between the turntable 2 and the side portion 13 of the container body 12. An exhaust pipe 630 is connected to the exhaust port 61, and this exhaust pipe 630 is connected via a pressure regulator 650 to a vacuum pump 640 which is a vacuum exhaust means.

[0033] A heater unit 7, which is a heating means, is provided in the space between the bottom 14 of the processing vessel 1 and the turntable 2. The heater unit 7 heats the substrate W on the turntable 2 to a target temperature (e.g., 300° C.) determined by a recipe. A ring-shaped cover member 71 is provided below the periphery of the turntable 2 to prevent gas from entering the space below the turntable 2.

[0034] The bottom 14 at a portion closer to the center of rotation than the space in which the heater unit 7 is disposed is a protruding portion 12a that protrudes upward so as to approach the core portion 21 at the center of the lower surface of the turntable 2. A narrow space is formed between the protruding portion 12a and the core portion 21. In addition, the gap between the inner peripheral surface of the through hole of the rotating shaft 22 penetrating the bottom 14 and the rotating shaft 22 is narrow, and this narrow space is connected to the case body 20. A lid member 7a is provided between the heater unit 7 and the turntable 2, covering the area between the cover member 71 and the upper end of the protruding portion 12a in the circumferential direction. The lid member 7a is made of, for example, quartz, and suppresses the intrusion of gas into the heater unit 7.

[0035] A purge gas supply pipe 72 that supplies N2 gas, which is a purge gas (the same gas as the separation gas supplied by the separation gas nozzle 34N), into the narrow space is provided in the case body 20. Furthermore, a plurality of purge gas supply pipes 73 for purging the arrangement space of the heater unit 7 are provided at appropriate intervals along the circumferential direction in the bottom portion 14 below the heater unit 7.

[0036] When purge gas is supplied from the purge gas supply pipe 72, the purge gas flows through a gap between the inner circumferential surface of the through hole of the rotating shaft 22 and the rotating shaft 22, and a gap between the protruding portion 12a and the core portion 21, into the space between the turntable 2 and the lid member 7a, and is exhausted from the multiple exhaust ports 61. When purge gas is supplied from the purge gas supply pipe 73, the purge gas flows out from the space in which the heater unit 7 is accommodated through a gap (not shown) between the lid member 7a and the cover member 71, and is exhausted from the multiple exhaust ports 61. Due to these flows of purge gas, it is possible to prevent the source gas and the reaction gas from mixing through the space below the center of the processing vessel 1 and the space below the turntable 2.

[0037] In addition, a separation gas supply pipe 51 is connected to the center of the top plate 11 of the processing vessel 1. The separation gas supply pipe 51 supplies a separation gas (the same gas as the separation gas supplied by the separation gas nozzle 34N) to the space between the top plate 11 and the core portion 21. The separation gas supplied to this space flows along the surface of the turntable 2 through the narrow space between the protruding portion 5 and the turntable 2. The space between the protruding portion 5 and the turntable 2 is maintained at a pressure higher than that of the separation gas. Therefore, the raw material gas and the reaction gas are prevented from mixing through the central region C.

[0038] 2, a transfer port 16 is formed in the side wall of the processing vessel 1, through which the substrate W is transferred between an external transfer arm (not shown) and the turntable 2. This transfer port 16 is opened and closed by a gate valve (not shown). A recess 24, which is a substrate placement area in the turntable 2, is located opposite the transfer port 16, and receives and transfers the substrate W between the recess 24 and the transfer arm. For this reason, the substrate processing apparatus 100 is provided with a lift pin and a lift mechanism (neither of which are shown) adjacent to the transfer port 16 on the lower side of the turntable 2, which penetrate the recess 24 and lift the substrate W from the backside.

[0039] The substrate processing apparatus 100 also includes a control unit 90 that controls the operation of the entire apparatus. The control unit 90 is a computer having one or more processors, a memory, an input / output interface, and a communication interface (not shown). The one or more processors are one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit made of a plurality of discrete semiconductors, and executes and processes a program stored in the memory. The memory includes a main storage device made of a semiconductor memory or the like, and an auxiliary storage device made of a disk, a semiconductor memory (flash memory), or the like.

[0040] The above-described substrate processing apparatus 100 supplies a source gas, a reaction gas, a dehydration gas, and a separation gas to the processing chamber of the processing vessel 1 under the control of the controller 90. In particular, the dehydration gas nozzle 33N and the separation gas nozzle 34N supply separation gas to the separation space H below the convex portion 4, so that the processing vessel 1 can be separated into a source gas processing space P1 to which the source gas is supplied and a reaction gas processing space P2 to which the reaction gas is supplied, in a plan view.

[0041] FIG. 4 is an explanatory diagram showing the movement of molecules on the substrate W in the reactive gas processing space P2. FIG. 5 is an explanatory diagram showing the movement of molecules on the substrate W in the second separation space H2 and the source gas processing space P1. As shown in FIG. 4, the reactive gas processing space P2 corresponds to an arc-shaped range from the first separation space H1 of the convex part 4 (on the right side in FIG. 4) equipped with the dehydration gas nozzle 33N in a clockwise direction to just before the convex part 4 (on the upper left side in FIG. 4) equipped with the separation gas nozzle 34N. That is, the reactive gas processing space P2 is set to a range wider than the source gas processing space P1. In a plan view of the processing vessel 1 in FIG. 4, the reactive gas processing space P2 occupies a range from approximately 3 o'clock to approximately 10 o'clock (more than 1 / 2 of the processing chamber of the processing vessel 1).

[0042] 5, the raw material gas processing space P1 corresponds to an arc-shaped range between the second separation space H2 of the convex portion 4 equipped with the separation gas nozzle 34N and the first separation space H1 of the convex portion 4 equipped with the dehydration gas nozzle 33N. In the plan view of the processing vessel 1 in FIG. 4, the raw material gas processing space P1 occupies a range from approximately 11 o'clock to approximately 3 o'clock.

[0043] Next, the significance of supplying a dehydration gas in addition to a source gas and a reactive gas in the substrate processing apparatus 100 according to this embodiment will be described with reference to the lower diagrams of FIG. 4 and FIG.

[0044] 4, at the start of the reaction gas processing space P2, a precursor containing zirconium (Zr) (hereinafter referred to as a zirconium precursor) supplied as a raw material gas is adsorbed on the surface of the substrate W. An example of this zirconium precursor is tetrakis(dimethylamino)zirconium, in which (NMe2)4 and cyclopentane are bonded to zirconium.

[0045] In the reactive gas processing space P2, ozone (O3) gas is discharged as a reactive gas from the reactive gas nozzle 32N to the zirconium precursor. The ozone decomposes the carbon bonds of the zirconium precursor by ozonolysis (ozone oxidation). At this time, moisture (H2O), carbon dioxide (CO2), nitric oxide (NO), and the like are generated as reaction by-products in the reactive gas processing space P2. The zirconium precursor becomes zirconium oxide by ozonolysis, and hydroxyl groups (OH) are bonded to the surface of the zirconium oxide. The moisture (H2O) in the reactive gas processing space P2 may react excessively with the hydroxyl groups of zirconium and be adsorbed.

[0046] For this reason, in the reactive gas processing space P2 according to the embodiment, ethanol (EtOH) gas, which is a dehydration gas, is supplied from the dehydration gas nozzle 33N. This ethanol can break into the moisture attached to the hydroxyl groups of zirconium and bond with zirconium. As a result, the moisture is desorbed (dehydrated) from the hydroxyl groups of zirconium. The moisture released by the reaction is exhausted from the exhaust port 61 together with other gases and reaction by-products in the processing vessel 1.

[0047] Meanwhile, on the surface of zirconium oxide of the substrate W, ethanol remains on the hydroxyl groups bonded to zirconium. Therefore, in the reactive gas processing space P2 according to the embodiment, ozone gas is further supplied to the surface of zirconium oxide after ethanol has adhered thereto. This causes the adhered ethanol to be desorbed from the hydroxyl groups of zirconium. As a result, a state is created in which no moisture or ethanol remains on the surface of zirconium oxide downstream of the reactive gas processing space P2.

[0048] That is, as shown in Fig. 5, in the second separation space H2 of the convex portion 4 where the separation gas nozzle 34N is located, zirconium oxide in a state where only hydroxyl groups are bonded to zirconium (water and ethanol have been sufficiently removed) moves in. Therefore, in the second separation space H2, although the separation gas is discharged from the separation gas nozzle 34N, the hydroxyl groups bonded to the zirconium remain in an unbonded state.

[0049] In the raw material gas processing space P1, a zirconium precursor, which is the next raw material gas, is discharged from the raw material gas nozzle 31N to the zirconium oxide. The zirconium precursor is easily bonded to the zirconium in the lower layer by covalent bonding (Zr-O bond) to the zirconium having a hydroxyl group, and is laminated on the upper layer.

[0050] As described above, the substrate processing apparatus 100 can supply ethanol, which is a dehydrating gas, to effectively dehydrate moisture adhering to the surface of the substrate W, and can smoothly deposit the next source gas. In other words, the substrate processing apparatus 100 can stably form a zirconium oxide film, and can easily control the film thickness to a target value.

[0051] The substrate processing apparatus 100 according to the embodiment is basically configured as described above, and its operation (film forming method) and effects will be described below.

[0052] Fig. 6 is a flow chart showing a film formation method of the substrate processing apparatus 100 according to the embodiment. The substrate processing apparatus 100 executes steps S101 to S107 shown in Fig. 6 under the control of the controller 90. However, as described above, the substrate processing apparatus 100 according to the embodiment performs a film formation process by supplying each gas to each substrate W while rotating each substrate W placed on the turntable 2. Therefore, it can be said that the substrate processing apparatus 100 performs steps S102 to S106 in Fig. 6 simultaneously in terms of time, and performs the processes of steps S102 to S106 in Fig. 6 sequentially for each substrate W depending on the spatial division during rotation of the turntable 2.

[0053] Specifically, the control unit 90 first opens the gate valve, and causes the transfer arm to load the substrate W through the transfer port 16 (FIG. 3) and place it in the recess 24 of the turntable 2 (step S101). At this time, the control unit 90 intermittently rotates the turntable 2 to sequentially place the substrates W in each recess 24. After each substrate W is loaded, the control unit 90 closes the gate valve to seal the processing chamber 1.

[0054] Furthermore, as a preparation for the film formation process, the control unit 90 discharges a separation gas from the dehydration gas nozzle 33N and the separation gas nozzle 34N, and evacuates the gas using the vacuum pump 640 and the pressure regulator 650, thereby adjusting the entire processing chamber of the processing vessel 1 to a target pressure. At this time, the control unit 90 may also discharge a separation gas and a purge gas from the separation gas supply pipe 51 and the purge gas supply pipes 72, 73. Next, the control unit 90 heats the substrate W to a target temperature by the heater unit 7 while rotating the turntable 2 clockwise at a target rotation speed.

[0055] When the advance preparation is completed, the control unit 90 controls the gas supply unit 30 to supply the raw material gas, the reactive gas, the dehydration gas, and the separation gas into the processing vessel 1. The raw material gas, the reactive gas, and the dehydration gas are separated in the separation space H (first separation space H1, second separation space H2) having the two convex portions 4, and are prevented from being mixed with each other in the processing vessel 1.

[0056] 6 are repeated for each substrate W based on the rotation of the turntable 2. In detail, in step S102, when the substrate W passes through the source gas processing space P1 due to the rotation of the turntable 2, the source gas (zirconium precursor) supplied from the source gas nozzle 31N is adsorbed onto the surface of the substrate W.

[0057] In step S103, when the substrate W on the turntable 2 passes through the first separation space H1 after the raw material gas processing space P1, a dehydration gas (ethanol) and a separation gas are supplied from the dehydration gas nozzle 33N. The first separation space H1 constitutes a part of the reactive gas processing space P2, and the dehydration gas supplied to the substrate W moves to the reactive gas processing space P2 along the rotation direction of the turntable 2. In addition, the separation gas discharged from the dehydration gas nozzle 33N flows into the raw material gas processing space P1 and the reactive gas processing space P2 while increasing the pressure in the first separation space H1, thereby separating these spaces.

[0058] In step S104, the substrate W on the turntable 2 moves to the reactive gas processing space P2 after the first separation space H1, whereby the reactive gas (ozone gas) supplied from each reactive gas nozzle 32N mixes with the previously supplied dehydration gas in the reactive gas processing space P2. As a result, in the reactive gas processing space P2, a reaction occurs between the zirconium precursor on the surface of the substrate W, the ozone, and the ethanol, as described in FIG. 4. In the reactive gas processing space P2, moisture near the surface of the substrate W is desorbed (dehydrated) by the dehydration gas, and the ethanol is further removed by the reactive gas.

[0059] In particular, three reactive gas nozzles 32N are provided in the rear half of the reactive gas processing space P2 and are covered with an activation plate 80. This makes it possible to effectively remove ethanol even if the ethanol is bonded to the hydroxyl group of zirconium in the substrate W. As a result, in the reactive gas processing space P2, the source gas adsorbed on the surface of the substrate W can be effectively oxidized, and a high-quality oxide thin film can be formed on the surface of the substrate W.

[0060] In step S105, when the substrate W on the turntable 2 passes through the second separation space H2 after the reactive gas processing space P2, a separation gas is supplied from the separation gas nozzle 34N. The separation gas discharged from the separation gas nozzle 34N can blow away moisture and dehydration gas desorbed from the substrate W. The separation gas also flows into the source gas processing space P1 and the reactive gas processing space P2 while increasing the pressure in the second separation space H2, thereby separating these regions.

[0061] In step S106, the control unit 90 determines whether or not to continue the film formation process, and if the film formation process is to be continued (step S106: YES), the process returns to step S102 and repeats the same process flow. In other words, in the film formation method, the rotation of the turntable 2 is continued to repeat the cycle of steps S102 to S106. As a result, a molecular layer of an oxide film is gradually deposited on the surface of the substrate W. Also, for example, the control unit 90 monitors the execution period of the film formation process, and determines the end of the film formation process when a target execution period has elapsed (step S106: NO).

[0062] When the control unit 90 determines that the film formation process is completed, it stops the supply of each gas to the processing vessel 1 and the rotation of the turntable 2, and unloads the substrate W from the processing vessel 1 in the reverse order to the order in which the substrate W was loaded (step S107). This completes the film formation method.

[0063] By carrying out the above-described film formation method, the substrate processing apparatus 100 can form a zirconium oxide film with high accuracy (to a desired film thickness) on the surface of the substrate W. That is, the presence of the reactive gas and the dehydration gas in the reactive gas processing space P2 desorbs moisture adhering to the precursor adsorbed on the substrate W. This allows the zirconium in the lower layer and the zirconium in the upper layer to be stably bonded.

[0064] FIG. 7 is a table comparing the film thickness of the film formation process when ethanol is supplied and the film thickness of the film formation process when ethanol is not supplied. The image in FIG. 7 is an image of one trench formed on the substrate W. The gray parts of the image are the walls of the substrate W that constitute the trench, and the black parts of the image are the film formed by the film formation process. In addition, "Top", "Top side", "1 μm depth", "2 μm depth", "3 μm depth", and "Bottom" in FIG. 7 are names given when dividing each part from the top to the bottom of the trench, and "1 μm depth", "2 μm depth", and "3 μm depth" indicate the depth from "Top". Furthermore, the "reference thickness" in FIG. 7 is the target value of the film thickness of the film formed on the trench. "Overhang" is the ratio of the film thickness of the film formed on the top of the trench to the reference thickness. "Step coverage" is the ratio of the film thickness of the film formed on the bottom of the trench to the reference thickness.

[0065] In the table of FIG. 7, when the film formation process in which ethanol is supplied is compared with the film formation process in which ethanol is not supplied, it can be seen that both the overhang and the step coverage are improved. That is, in the comparative example in which ethanol is not supplied, when the substrate W is oxidized with a reactive gas after the source gas is adsorbed thereon, moisture is generated during the oxidation, and the moisture reacts excessively with the precursor adsorbed on the substrate W. This results in an excessive film being formed on the top of the trench. For example, the overhang when ethanol is not supplied is 105%, which indicates that a film thickness greater than the target is formed on the top of the trench.

[0066] In contrast, when ethanol is supplied, the moisture generated during oxidation after the adsorption of the source gas is dehydrated, suppressing excess reaction with the precursor. For example, the overhang when ethanol is supplied is 100% in Figure 7, indicating that the target film thickness is obtained.

[0067] The step coverage when ethanol is not supplied is 62.3%. This indicates that excess reaction due to moisture is likely to occur at the top of the trench, and a film is not sufficiently formed at the bottom of the trench. On the other hand, the step coverage when ethanol is supplied is 85.4%. This indicates that by dehydrating the moisture with ethanol, a film is sufficiently formed at the bottom of the trench.

[0068] As described above, the substrate processing apparatus 100 and film forming method according to the embodiment can make the thickness of the film formed in the trench more conformal by supplying ethanol, which is a dehydrating gas, thereby improving the quality of the film.

[0069] The substrate processing apparatus 100 and the film forming method according to the embodiment are not limited to the above embodiment, and may be modified in various ways. For example, the dehydration gas supply unit 33 (dehydration gas nozzle 33N) that supplies the dehydration gas to the processing vessel 1 is not limited to being provided in the first separation space H1, but may be provided anywhere within the reactive gas processing space P2. As an example, the dehydration gas nozzle 33N may be provided at a position between one or more reactive gas nozzles 32N and another one or more reactive gas nozzles 32N in the reactive gas processing space P2. Alternatively, the dehydration gas nozzle 33N may be provided downstream (inner side in the rotation direction) of all of the one or more reactive gas nozzles 32N. Even in this case, the dehydration gas can be desorbed by the reactive gas remaining in the reactive gas processing space P2.

[0070] Furthermore, the substrate processing apparatus 100 according to the embodiment is configured to rotate (revolve) multiple substrates W using a turntable 2, but is not limited thereto. For example, the apparatus may be configured to rotate (spin) each of the mounting portions supporting the substrates W on the turntable 2.

[0071] Furthermore, the substrate processing apparatus 100 is not limited to a configuration in which a turntable 2 is provided inside the processing vessel 1 and multiple substrates W are processed. For example, the substrate processing apparatus 100 may be configured as a single-wafer type apparatus in which a single substrate W is loaded into the processing vessel and a source gas, a reactive gas, and a dehydration gas are sequentially supplied to the single substrate W to perform a film formation process. Alternatively, the substrate processing apparatus 100 may be configured as a batch type apparatus in which a multiple substrates W are accommodated in the processing vessel in a vertical or horizontal arrangement and a source gas, a reactive gas, and a dehydration gas are sequentially supplied to the multiple substrates W to perform a film formation process.

[0072] In a single-wafer or batch-type substrate processing apparatus, a gas supply state similar to that of the above-described substrate processing apparatus 100 is formed based on the supply timing of gas into the processing chamber. For example, Fig. 8 is a flow chart showing an example of a film forming method in which various gases are supplied at different timings.

[0073] A single-wafer or batch-type substrate processing apparatus supplies various gases in accordance with, for example, the process flow shown in Fig. 8. First, the substrate processing apparatus performs a step of supplying a source gas (zirconium precursor) to a processing vessel containing one or more substrates W (step S201). After performing this source gas supply step for a set period (e.g., 15 seconds), the substrate processing apparatus then performs a step of supplying a purge gas (an inert gas such as N2) to exhaust the source gas remaining in the processing vessel (step S202).

[0074] After the step of supplying the purge gas is performed for a set period (e.g., 15 seconds), the substrate processing apparatus then performs a step of supplying a reactive gas (ozone gas) (step S203). This allows the raw material gas adsorbed on the substrate W to be oxidized by the reactive gas. After the step of supplying the reactive gas is performed for a set period (e.g., 30 seconds), the substrate processing apparatus then performs a step of supplying a purge gas (step S204).

[0075] After the step of supplying the purge gas is performed for a set period (e.g., 15 seconds), the substrate processing apparatus then performs a step of supplying a dehydration gas (ethanol gas) (step S205). This allows the moisture bonded to the surface of the substrate W to be dehydrated by the dehydration gas. After the step of supplying the dehydration gas is performed for a set period (e.g., 15 seconds), the substrate processing apparatus then performs a step of supplying a purge gas (step S206).

[0076] After the step of supplying the purge gas is performed for a set period (e.g., 5 seconds), the substrate processing apparatus then performs a step of supplying a reactive gas (ozone gas) again (step S207). This allows the dehydration gas bonded to the surface of the substrate W to be desorbed by the reactive gas. After the step of supplying the reactive gas is performed for a set period (e.g., 5 seconds), the substrate processing apparatus then performs a step of supplying a purge gas (step S208). Then, by performing the step of supplying the purge gas for a set period (e.g., 5 seconds), one cycle of the film formation process is completed.

[0077] In step S209, the substrate processing apparatus determines whether or not to continue the film formation process, and if the film formation process is to be continued, returns to step S201 and repeats the same process. In the above film formation method, the single-wafer or batch-type substrate processing apparatus can accurately control the thickness of the film formed on the surface of the substrate W.

[0078] The technical ideas and effects of the present disclosure explained in the above embodiments will be described below.

[0079] A substrate processing apparatus 100 according to a first aspect of the present disclosure includes a processing vessel 1, a raw material gas supply unit 31 that supplies a raw material gas into the processing vessel 1, a reactive gas supply unit 32 that supplies a reactive gas that reacts with the raw material gas into the processing vessel 1, and a dehydration gas supply unit 33 that supplies a dehydration gas into the processing vessel 1 to desorb moisture. Inside the processing vessel 1, with the substrate W contained therein, the raw material gas is supplied to the substrate W, and then the reactive gas and dehydration gas are supplied to the substrate W.

[0080] As described above, the substrate processing apparatus 100 supplies a reactive gas and a dehydration gas in a film formation process, thereby enabling a film to be formed with high accuracy on the substrate W. For example, in the case of a substrate W having irregularities such as trenches, the substrate processing apparatus 100 supplies a reactive gas and a dehydration gas, thereby enabling a conformal film thickness to be obtained.

[0081] The processing vessel 1 also has a space (reactive gas processing space P2) for mixing the reactive gas supplied by the reactive gas supply unit 32 and the dehydration gas supplied by the dehydration gas supply unit 33. This allows both the reaction of the reactive gas with the raw material gas and the dehydration by the dehydration gas to be promoted on the surface of the substrate W in the space of the dehydration gas and reactive gas in the processing vessel 1.

[0082] In addition, in the processing vessel 1, after the dehydration gas is supplied to the substrate W, at least the reactive gas is supplied to the substrate W. In this manner, the substrate processing apparatus 100 can desorb the excess dehydration gas by the reactive gas, and can suppress a decrease in film thickness caused by the remaining dehydration gas.

[0083] In addition, a separation gas that spatially or temporally separates the supplied source gas from the supplied reactive gas and dehydration gas is supplied into the processing vessel 1. This allows the substrate processing apparatus 100 to reduce adhesion of the source gas and reactive gas to components such as the inner surface of the processing vessel 1 due to reaction between the source gas and the reactive gas.

[0084] The processing vessel 1 further includes a turntable 2 rotatably provided within the processing chamber 1 and having a plurality of mounting portions (recesses 24) on which substrates W are mounted at positions away from the center of rotation, the raw material gas supply unit 31 having a raw material gas nozzle 31N that crosses the rotation direction of the turntable 2 and discharges raw material gas toward the mounting portion, the reactive gas supply unit 32 having a reactive gas nozzle 32N that crosses the rotation direction of the turntable 2 and discharges raw material gas toward the mounting portion, and the dehydration gas supply unit 33 having a dehydration gas nozzle 33N that crosses the rotation direction of the turntable 2 and discharges dehydration gas toward the mounting portion. This allows the substrate processing apparatus 100 to perform film formation processing on the plurality of substrates W mounted on the turntable 2 with high accuracy.

[0085] In addition, the dehydration gas nozzle 33N supplies a separation gas that separates the source gas discharged from the source gas nozzle 31N and the reactive gas discharged from the reactive gas nozzle 32N together with the dehydration gas. This enables the substrate processing apparatus 100 to separate the source gas and the reactive gas by the separation gas and to stably supply the dehydration gas to the surface of the substrate W.

[0086] The dehydration gas nozzle 33N is disposed in a space (first separation space H1) capable of forming a pressure higher than the pressure of the space (source gas processing space P1) into which the source gas is discharged and the pressure of the space (reactive gas processing space P2) into which the reactive gas is discharged inside the processing vessel 1. This allows the substrate processing apparatus 100 to more reliably separate the source gas space and the reactive gas space inside the processing vessel 1.

[0087] The source gas is a gas containing any one of the metals zirconium, hafnium, aluminum, and silicon. This allows the substrate processing apparatus 100 to deposit these films on the surfaces of the substrates W satisfactorily.

[0088] The reactive gas is a gas containing ozone, whereby the substrate processing apparatus 100 can promote oxidation of the source gas adsorbed on the surface of the substrate W.

[0089] The dehydration gas contains ethanol, so that the substrate processing apparatus 100 can stably dehydrate the moisture generated by the reaction between the source gas and the reactive gas.

[0090] Moreover, the film formation method according to the second aspect of the present disclosure includes a step of supplying a source gas into the processing vessel 1 accommodating the substrate W, and, after the step of supplying the source gas, a reaction gas that reacts with the source gas and a dehydration gas that desorbs moisture into the processing vessel 1 accommodating the substrate W. Even in this case, the film formation method can form a film on the substrate W with high accuracy.

[0091] The substrate processing apparatus 100 and the film forming method according to the presently disclosed embodiment are illustrative and not restrictive in all respects. The embodiments can be modified and improved in various forms without departing from the spirit and scope of the appended claims. The matters described in the above embodiments can be configured in other ways without any contradiction, and can be combined without any contradiction. [Explanation of symbols]

[0092] 1 Processing vessel 31 Raw gas supply section 32 Reactive gas supply section 33 Dehydration gas supply section 90 Control section 100 Substrate processing apparatus W substrate

Claims

1. A processing vessel; a source gas supply unit that supplies a source gas into the processing chamber; a reactive gas supply unit for supplying a reactive gas that reacts with the source gas into the processing chamber; a dehydration gas supply unit that supplies a dehydration gas into the processing vessel to desorb moisture, In the processing vessel, the source gas is supplied to the substrate while the substrate is accommodated therein, and then the reaction gas and the dehydration gas are supplied to the substrate. Substrate processing equipment.

2. the processing vessel has a space for mixing the reactive gas supplied by the reactive gas supply unit and the dehydration gas supplied by the dehydration gas supply unit; The substrate processing apparatus according to claim 1 .

3. In the processing chamber, after the dehydration gas is supplied to the substrate, at least the reaction gas is supplied to the substrate. The substrate processing apparatus according to claim 2 .

4. A separation gas is supplied into the processing vessel to spatially or temporally separate the raw material gas, the reaction gas, and the dehydration gas. The substrate processing apparatus according to claim 2 .

5. a rotary table rotatably provided within the processing vessel, the rotary table having a plurality of placement portions for placing the substrate at a position away from a rotation center; the source gas supply unit has a source gas nozzle that ejects the source gas toward the placement unit across a rotation direction of the turntable, the reaction gas supply unit has a reaction gas nozzle that ejects the source gas toward the placement unit across a rotation direction of the turntable, the dehydration gas supply unit has a dehydration gas nozzle that ejects the dehydration gas toward the placement unit across a rotation direction of the turntable, The substrate processing apparatus according to claim 1 .

6. the dehydration gas nozzle supplies a separation gas that separates the source gas discharged from the source gas nozzle and the reaction gas discharged from the reaction gas nozzle together with the dehydration gas; The substrate processing apparatus according to claim 5 .

7. the dehydration gas nozzle is disposed in a space inside the processing vessel where a pressure higher than a pressure of a space into which the source gas is discharged and a pressure of a space into which the reaction gas is discharged can be formed. The substrate processing apparatus according to claim 6 .

8. The raw material gas is a gas containing any one of zirconium, hafnium, aluminum, and silicon. The substrate processing apparatus according to claim 1 .

9. The reactive gas is a gas containing ozone. The substrate processing apparatus according to claim 1 .

10. The dehydrated gas is a gas containing ethanol. The substrate processing apparatus according to claim 1 .

11. supplying a source gas into a processing vessel containing a substrate; and after the step of supplying the source gas, supplying a reaction gas that reacts with the source gas and a dehydration gas that desorbs moisture into the processing vessel containing the substrate. Film formation method.

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