JP6857760B2 - Semiconductor device manufacturing methods, substrate processing devices, and programs - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor device, a substrate processing device, and a program.

As one step in the manufacturing process of a semiconductor device, a process of forming a film on a substrate may be performed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-118462

An object of the present invention is to provide a technique capable of controlling the in-plane film thickness distribution of a film formed on a substrate.

According to one aspect of the invention
(A) A step of forming the first layer by supplying the raw material to the substrate from the first nozzle, and
(B) A step of forming a second layer by supplying a reactant to the substrate from a second nozzle different from the first nozzle.
It has a step of forming a film on the substrate by performing a cycle of performing the above non-simultaneously a predetermined number of times.
In (a) above,
(A-1) A step of supplying the inert gas from the second nozzle at a first flow rate smaller than the flow rate of the raw material while the raw material is supplied from the first nozzle.
(A-2) A step of supplying the inert gas from the second nozzle at a second flow rate larger than the flow rate of the raw material while the raw material is being supplied from the first nozzle.
The technique of performing in this order is provided.

According to the present invention, it is possible to control the in-plane film thickness distribution of the film formed on the substrate.

It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus preferably used in embodiment of this invention, and is the figure which shows the processing furnace part in the vertical sectional view. It is a schematic block diagram of a part of the vertical processing furnace of the substrate processing apparatus preferably used in embodiment of this invention, and is the figure which shows the part of the processing furnace by the cross-sectional view taken along line AA of FIG. It is a schematic block diagram of the controller of the substrate processing apparatus preferably used in embodiment of this invention, and is the figure which shows the control system of the controller by the block diagram. It is a figure which shows the film formation sequence of one Embodiment of this invention. It is a figure which illustrates the change of the formation rate of the Si-containing layer on a substrate. (A) and (b) are cross-sectional views showing a modified example of a vertical processing furnace, respectively, and are views showing a reaction tube, a buffer chamber, a nozzle and the like partially extracted. (A) to (c) are diagrams showing the evaluation results of the in-plane film thickness distribution of the film formed on the substrate, respectively. (A) to (c) are diagrams showing the evaluation results of the in-plane film thickness distribution of the film formed on the substrate, respectively. (A) to (c) are diagrams showing the evaluation results of the in-plane film thickness distribution of the film formed on the substrate, respectively.

<One Embodiment of the present invention>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

(1) Configuration of Substrate Processing Device As shown in FIG. 1, the processing furnace 202 has a heater 207 as a heating means (heating mechanism). The heater 207 has a cylindrical shape and is vertically installed by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation portion) for activating (exciting) the gas with heat.

Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made _{of a heat-resistant material such as quartz (SiO 2} ) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end open. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of a metal such as stainless steel (SUS), and is formed in a cylindrical shape with open upper and lower ends. The upper end of the manifold 209 is engaged with the lower end of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a as a sealing member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is installed vertically like the heater 207. The processing vessel (reaction vessel) is mainly composed of the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow portion of the processing container. The processing chamber 201 is configured to accommodate the wafer 200 as a substrate.

In the processing chamber 201, nozzles 249a as a first nozzle and nozzles 249b and 249c as a second nozzle are provided so as to penetrate the side wall of the manifold 209. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively. The second nozzle is a nozzle different from the first nozzle, and the nozzles 249a, 249b, and 249c are different nozzles.

The gas supply pipes 232a to 232c are provided with mass flow controllers (MFCs) 241a to 241c which are flow rate controllers (flow control units) and valves 243a to 243c which are on-off valves, respectively, in order from the upstream side of the gas flow. .. Gas supply pipes 232e and 232d for supplying the inert gas are connected to the downstream side of the gas supply pipes 232a and 232b with respect to the valves 243a and 243b, respectively. The gas supply pipes 232e and 232d are provided with MFC 241e and 241d and valves 243e and 243d, respectively, in this order from the upstream side of the gas flow.

As shown in FIG. 2, the nozzles 249a to 249c are arranged in an annular space in a plan view between the inner wall of the reaction tube 203 and the wafer 200, along the upper part of the inner wall of the reaction tube 203 from the lower part of the wafer 200. Each is provided so as to stand upward in the arrangement direction. That is, the nozzles 249a to 249c are provided along the wafer arrangement region in the region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region in which the wafer 200 is arranged. The nozzle 249a is arranged so as to face the exhaust port 231a, which will be described later, in a straight line with the center of the wafer 200 carried into the processing chamber 201 in plan view. The nozzles 249b and 249c are arranged on both sides of the nozzle 249a so as to sandwich the nozzles 249a from both sides along the inner wall of the reaction tube 203 (outer circumference of the wafer 200). Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. Each of the gas supply holes 250a to 250c is opened so as to face the exhaust port 231a, so that gas can be supplied toward the wafer 200. A plurality of gas supply holes 250a to 250c are provided from the lower part to the upper part of the reaction tube 203.

From the gas supply pipe 232a, as a raw material (raw material gas), for example, a halosilane gas containing Si as a predetermined element (main element) and a halogen element enters the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a. Be supplied. The raw material gas is a raw material in a gaseous state, for example, a gas obtained by vaporizing a raw material in a liquid state under normal temperature and pressure, a raw material in a gaseous state under normal temperature and pressure, and the like. Halosilane is a silane having a halogen group. The halogen group includes a chloro group, a fluoro group, a bromo group, an iodine group and the like. That is, the halogen group contains halogen elements such as chlorine (Cl), fluorine (F), bromine (Br) and iodine (I). As the halosilane-based gas, for example, a raw material gas containing Si and Cl, that is, a chlorosilane-based gas can be used. The chlorosilane-based gas acts as a Si source. As the chlorosilane-based gas, for example, dichlorosilane (SiH ₂ Cl ₂ , abbreviation: DCS) gas can be used.

From the gas supply pipe 232b, hydrogen nitride-based gas, which is a nitride gas as a nitrogen (N) -containing gas, is used as a reactant (reactant) having a chemical structure (molecular structure) different from that of the raw material. It is supplied into the processing chamber 201 via the nozzle 249b. The hydrogen nitride-based gas acts as an N source. As the hydrogen nitride-based gas, for example, ammonia (NH ₃ ) gas can be used.

From the gas supply pipes 232c to 232e, for example, nitrogen (N ₂ ) gas is emitted as an inert gas via MFC 241c to 241e, valves 243c to 243e, gas supply pipes 232c to 232a, and nozzles 249c to 249a, respectively. It is supplied into 201. The N ₂ gas acts as a purge gas and a carrier gas, and further acts as a film thickness distribution control gas that controls the in-plane film thickness distribution of the film formed on the wafer 200.

The raw material supply system is mainly composed of the gas supply pipe 232a, the MFC 241a, and the valve 243a. Further, the reactant supply system is mainly composed of the gas supply pipe 232b, the MFC 241b, and the valve 243b. Further, the inert gas supply system is mainly composed of the gas supply pipes 232c to 232e, the MFC 241c to 241e, and the valves 243c to 243e.

Of the various supply systems described above, any or all of the supply systems may be configured as an integrated supply system 248 in which valves 243a to 243e, MFC 241a to 241e, and the like are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232e, and supplies various gases into the gas supply pipes 232a to 232e, that is, the opening / closing operation of the valves 243a to 243e and the MFC 241a to 241e. The flow rate adjustment operation and the like are configured to be controlled by the controller 121 described later. The integrated supply system 248 is configured as an integrated or divided integrated unit, and can be attached to and detached from the gas supply pipes 232a to 232e in units of the integrated unit. It is configured so that maintenance, replacement, expansion, etc. can be performed on an integrated unit basis.

The reaction tube 203 is provided with an exhaust port 231a for exhausting the atmosphere in the processing chamber 201. As shown in FIG. 2, the exhaust port 231a is provided at a position facing (facing) the nozzles 249a, 249b, 249c (gas supply holes 250a, 250b, 250c) with the wafer 200 interposed therebetween in a plan view. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is provided via a pressure sensor 245 as a pressure detector (pressure detector) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure regulator). , A vacuum pump 246 as a vacuum exhaust device is connected. The APC valve 244 can perform vacuum exhaust and vacuum exhaust stop in the processing chamber 201 by opening and closing the valve with the vacuum pump 246 operating, and further, with the vacuum pump 246 operating, the APC valve 244 can perform vacuum exhaust and vacuum exhaust stop. By adjusting the valve opening degree based on the pressure information detected by the pressure sensor 245, the pressure in the processing chamber 201 can be adjusted. The exhaust system is mainly composed of an exhaust pipe 231, an APC valve 244, and a pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

Below the manifold 209, a seal cap 219 is provided as a furnace palate body capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal such as SUS and is formed in a disk shape. An O-ring 220b as a sealing member that comes into contact with the lower end of the manifold 209 is provided on the upper surface of the seal cap 219. Below the seal cap 219, a rotation mechanism 267 for rotating the boat 217, which will be described later, is installed. The rotation shaft 255 of the rotation mechanism 267 penetrates the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be vertically lifted and lowered by a boat elevator 115 as a lifting mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transport device (convey mechanism) for loading and unloading (conveying) the wafer 200 into and out of the processing chamber 201 by raising and lowering the seal cap 219. Further, below the manifold 209, a shutter 219s as a furnace palate body capable of airtightly closing the lower end opening of the manifold 209 is provided in a state where the seal cap 219 is lowered and the boat 217 is carried out from the processing chamber 201. There is. The shutter 219s is made of a metal such as SUS and is formed in a disk shape. An O-ring 220c as a sealing member that comes into contact with the lower end of the manifold 209 is provided on the upper surface of the shutter 219s. The opening / closing operation of the shutter 219s (elevating / lowering operation, rotating operation, etc.) is controlled by the shutter opening / closing mechanism 115s.

The boat 217 as a substrate support supports a plurality of wafers, for example 25 to 200 wafers, in a horizontal position and vertically aligned with each other, that is, in multiple stages. It is configured to be arranged at intervals. The boat 217 is made of a heat resistant material such as quartz or SiC. In the lower part of the boat 217, a heat insulating plate 218 made of a heat-resistant material such as quartz or SiC is supported in multiple stages.

A temperature sensor 263 as a temperature detector is installed in the reaction tube 203. By adjusting the degree of energization of the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature in the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. Has been done. The RAM 121b, the storage device 121c, and the I / O port 121d are configured so that data can be exchanged with the CPU 121a via the internal bus 121e. An input / output device 122 configured as, for example, a touch panel is connected to the controller 121.

The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), or the like. In the storage device 121c, a control program for controlling the operation of the substrate processing device, a process recipe in which the procedures and conditions for substrate processing described later are described, and the like are readablely stored. The process recipes are combined so that the controller 121 can execute each procedure in the substrate processing described later and obtain a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, etc. are collectively referred to simply as programs. In addition, a process recipe is also simply referred to as a recipe. When the term program is used in the present specification, it may include only a recipe alone, a control program alone, or both of them. The RAM 121b is configured as a memory area (work area) in which programs, data, and the like read by the CPU 121a are temporarily held.

The I / O port 121d includes the above-mentioned MFCs 241a to 241e, valves 243a to 243e, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc. It is connected to the.

The CPU 121a is configured to read and execute a control program from the storage device 121c and read a recipe from the storage device 121c in response to an input of an operation command from the input / output device 122 or the like. The CPU 121a adjusts the flow rate of various gases by the MFCs 241a to 241e, opens and closes the valves 243a to 243e, opens and closes the APC valve 244, and adjusts the pressure by the APC valve 244 based on the pressure sensor 245 so as to follow the contents of the read recipe. Operation, start and stop of vacuum pump 246, temperature adjustment operation of heater 207 based on temperature sensor 263, rotation and rotation speed adjustment operation of boat 217 by rotation mechanism 267, lifting operation of boat 217 by boat elevator 115, shutter opening and closing mechanism 115s It is configured to control the opening / closing operation of the shutter 219s and the like.

The controller 121 installs the above-mentioned program stored in an external storage device (for example, a magnetic disk such as a hard disk, an optical disk such as a CD, a magneto-optical disk such as MO, or a semiconductor memory such as a USB memory) 123 in a computer. Can be configured by. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. Hereinafter, these are collectively referred to simply as a recording medium. When the term recording medium is used in the present specification, it may include only the storage device 121c alone, it may include only the external storage device 123 alone, or it may include both of them. The program may be provided to the computer by using a communication means such as the Internet or a dedicated line without using the external storage device 123.

(2) Film formation processing A sequence example of forming a silicon nitride film (SiN film) on a wafer 200 as a substrate as one step of a manufacturing process of a semiconductor device using the above-mentioned substrate processing apparatus is shown in FIG. explain. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

The film formation sequence shown in FIG. 4 is
Step A of forming a Si-containing layer as the first layer by supplying DCS gas from the nozzle 249a to the wafer 200,
A step B of forming a silicon nitride layer (SiN layer) as a second layer by supplying NH ₃ gas from the nozzle 249b to the wafer 200,
A film containing Si and N, that is, a SiN film is formed on the wafer 200 by performing a cycle of performing the above non-simultaneously a predetermined number of times.

Further, in the film forming sequence shown in FIG. 4, in step A,
Step A1 in which the _{DCS gas is supplied from the nozzle 249a and the N 2} gas is supplied from the nozzles 249b and 249c at a first flow rate smaller than the flow rate of the DCS gas.
Step A2 in which the _{DCS gas is supplied from the nozzle 249a and the N 2} gas is supplied from the nozzles 249b and 249c at a second flow rate larger than the flow rate of the DCS gas.
In this order, the in-wafer film thickness distribution of the SiN film formed on the wafer 200 (hereinafter, also simply referred to as in-plane film thickness distribution) is controlled.

Here, as an example, SiN is used as the wafer 200 by using a bare wafer having a small surface area with no uneven structure formed on the surface and controlling the flow rate of _{N 2 gas via the nozzles 249b and 249c in steps A1 and A2.} An example will be described in which the in-plane film thickness distribution of the film is the thickest in the central portion of the wafer 200 and gradually becomes thinner as it approaches the peripheral portion (hereinafter, also referred to as a central convex distribution). If a film having a central convex distribution can be formed on a bare wafer, it is flat with little change in film thickness from the center to the periphery on a pattern wafer (product wafer) with a large surface area in which a fine uneven structure is formed on the surface. It is possible to form a film having a film thickness distribution (hereinafter, also referred to as a flat distribution).

In the present specification, the film formation sequence shown in FIG. 4 may be shown as follows for convenience. The same notation is used in the following description of the modified examples and the like.

(DCS → NH ₃ ) × n ⇒ SiN

When the term "wafer" is used in the present specification, it may mean the wafer itself or a laminate of a wafer and a predetermined layer or film formed on the surface thereof. When the term "wafer surface" is used in the present specification, it may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. In the present specification, when it is described that "a predetermined layer is formed on a wafer", it means that a predetermined layer is directly formed on the surface of the wafer itself, or a layer formed on the wafer or the like. It may mean forming a predetermined layer on top of it. The use of the term "wafer" in the present specification is also synonymous with the use of the term "wafer".

(Wafer charge and boat load)
When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter opening / closing mechanism 115s moves the shutter 219s to open the lower end opening of the manifold 209 (shutter open). After that, as shown in FIG. 1, the boat 217 supporting the plurality of wafers 200 is lifted by the boat elevator 115 and carried into the processing chamber 201 (boat load). In this state, the seal cap 219 is in a state of sealing the lower end of the manifold 209 via the O-ring 220b.

(Pressure adjustment and temperature adjustment)
The inside of the processing chamber 201 is evacuated (decompressed exhaust) by the vacuum pump 246 so that the inside of the processing chamber 201, that is, the space where the wafer 200 exists has a desired pressure (vacuum degree). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Further, the wafer 200 in the processing chamber 201 is heated by the heater 207 so as to have a desired film forming temperature. At this time, the state of energization of the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Further, the rotation mechanism 267 starts the rotation of the wafer 200. Exhaust in the processing chamber 201, heating and rotation of the wafer 200 are all continuously performed at least until the processing of the wafer 200 is completed.

(Film formation step)
After that, the next steps A and B are sequentially executed.

[Step A]
In this step, DCS gas is supplied to the wafer 200 in the processing chamber 201.

Specifically, the valve 243a is opened to allow DCS gas to flow into the gas supply pipe 232a. The flow rate of the DCS gas is adjusted by the MFC 241a, is supplied into the processing chamber 201 via the nozzle 249a, and is exhausted from the exhaust port 231a. At this time, DCS gas is supplied to the wafer 200. At the same time opening the valve 243 e, it may be supplied with _{N 2} gas to the gas supply pipe 232 e. The _{flow rate of the N 2} gas is adjusted by the MFC 241e, is supplied to the processing chamber 201 together with the DCS gas through the nozzle 249a, and is exhausted from the exhaust port 231a. In step A, through the nozzles 249a into the processing chamber 201 while supplying the DCS gas, the nozzle 249 b, performs the steps A1, A2 supplies a _{N 2} gas into the process chamber 201 through a 249 c, The details will be described later.

In step A, the supply flow rate of the DCS gas supplied from the nozzle 249a is, for example, a predetermined flow rate within the range of 1 to 2000 sccm, preferably 10 to 1000 sccm. _{The supply flow rate of the N 2} gas supplied from the nozzle 249a is, for example, a predetermined flow rate within the range of 0 to 1000 sccm. The DCS gas supply time is, for example, a predetermined time within the range of 1 to 120 seconds, preferably 1 to 60 seconds. The pressure in the processing chamber 201 is, for example, a predetermined pressure in the range of 1 to 2666 Pa, preferably 67 to 1333 Pa. The temperature (deposition temperature) of the wafer 200 is, for example, a predetermined temperature within the range of 250 to 800 ° C., preferably 400 to 750 ° C., more preferably 550 to 700 ° C.

If the film forming temperature is less than 250 ° C., it becomes difficult for DCS to be chemically adsorbed on the wafer 200, and a practical film forming rate may not be obtained. This can be solved by setting the film formation temperature to 250 ° C. or higher. By setting the film forming temperature to 400 ° C. or higher, further 550 ° C. or higher, DCS can be more sufficiently adsorbed on the wafer 200, and a more sufficient film forming rate can be obtained.

If the film formation temperature exceeds 800 ° C., an excessive gas phase reaction occurs, the film thickness uniformity tends to deteriorate, and its control becomes difficult. By setting the film formation temperature to 800 ° C. or lower, an appropriate gas phase reaction can be generated, deterioration of film thickness uniformity can be suppressed, and its control becomes possible. In particular, by setting the film formation temperature to 750 ° C. or lower, and further to 700 ° C. or lower, it becomes possible to suppress the gas phase reaction and make the surface reaction dominant, and it becomes easy to secure the film thickness uniformity and control it easily. It becomes.

By supplying the DCS gas to the wafer 200 under the above-mentioned conditions, as the first layer, for example, less than one atomic layer to several atomic layers (less than one atomic layer to several molecular layers) on the outermost surface of the wafer 200. A Si-containing layer containing Cl of a certain thickness is formed. The Si-containing layer containing Cl may be a Si layer containing Cl, an adsorption layer of DCS, or both of them.

The Si layer containing Cl includes a continuous layer composed of Si and containing Cl, a discontinuous layer, and a Si thin film containing Cl formed by overlapping these layers. The Si constituting the Si layer containing Cl includes those in which the bond with Cl is not completely broken and those in which the bond with Cl is completely broken.

The adsorption layer of DCS includes a discontinuous adsorption layer as well as a continuous adsorption layer composed of DCS molecules. The DCS molecules constituting the adsorption layer of DCS include those in which the bond between Si and Cl is partially broken. That is, the adsorption layer of DCS may be a physical adsorption layer of DCS, a chemical adsorption layer of DCS, or both of them.

Here, a layer having a thickness of less than one atomic layer (molecular layer) means an atomic layer (molecular layer) formed discontinuously, and a layer having a thickness of one atomic layer (molecular layer). Means an atomic layer (molecular layer) that is continuously formed. The Cl-containing Si-containing layer may include both a Cl-containing Si layer and a DCS adsorption layer. However, since both have the same structure in which Cl is bonded to the main element (Si), for convenience, the Si-containing layer containing Cl is expressed as "one atomic layer", "several atomic layers", or the like. In some cases, "atomic layer" is synonymous with "molecular layer".

Under the condition that the DCS gas is autolyzed (thermally decomposed), the Si layer containing Cl is formed by depositing Si on the wafer 200. Under the condition that the DCS gas does not self-decompose (thermally decompose), the DCS is adsorbed on the wafer 200 to form an adsorption layer of the DCS. It is preferable to form a Si layer containing Cl rather than an adsorption layer of DCS in that the film formation rate can be increased. Hereinafter, the Si-containing layer containing Cl is also simply referred to as a Si-containing layer for convenience.

If the thickness of the first layer exceeds several atomic layers, the modification action in step B, which will be described later, does not reach the entire first layer. Moreover, the minimum value of the thickness of the first layer is less than one atomic layer. Therefore, the thickness of the first layer is preferably from less than one atomic layer to about several atomic layers. By setting the thickness of the first layer to one atomic layer or less, the action of modification in step B, which will be described later, can be relatively enhanced, and the time required for modification in step B can be shortened. .. The time required to form the first layer in step A can also be shortened. As a result, the processing time per cycle can be shortened, and the total processing time can be shortened. That is, it is possible to increase the film formation rate. Further, by setting the thickness of the first layer to one atomic layer or less, it is possible to improve the controllability of the film thickness uniformity.

Here, since abundant Si adsorption sites are present on the wafer 200 before the DCS gas is supplied, the first layer is formed at a relatively large formation rate at the initial stage of the DCS gas supply, and then the figure. As shown in 5, a large formation rate is maintained for a _{predetermined period (period T 1).} After that, when the formation of the first layer progresses and the amount of adsorption sites existing on the wafer 200 decreases, the timing (inflection point) at which the formation rate of the first layer drops significantly is reached. After reached the inflection point, time to the adsorption of the DCS to the wafer 200 above it is saturated (period T _2), the state in which the formation rate drops significantly is maintained.

In the initial stage of the above-mentioned period T ₁ , the DCS gas supplied from the nozzle 249a is actively consumed at the peripheral portion of the wafer 200, and tends to be difficult to reach the central portion of the wafer 200. Therefore, for example, when the supply of DCS gas to the wafer 200 is stopped before reaching the inflection point, the distribution of the thickness of the first layer in the in-plane of the wafer 200 (also referred to as the in-plane thickness distribution of the first layer). ) Is the thinnest in the central portion of the wafer 200 and gradually becomes thicker as it approaches the peripheral portion (hereinafter, also referred to as a central concave distribution). By continuing the supply of DCS gas to the wafer 200 without stopping the supply of DCS gas to the wafer 200 before the inflection point is reached and even after the inflection point is reached, the in-plane thickness distribution of the first layer is distributed. It is theoretically possible to move from a central concave distribution to a flat distribution. By continuing the supply of DCS gas, the consumption of DCS gas at the peripheral portion of the wafer 200 will eventually converge, and as a result, the amount of DCS gas reaching the central portion of the wafer 200 will gradually increase. Because it becomes. However, in this method, it is necessary to continue the supply of DCS gas for a long time, which may lead to an increase in gas cost or an increase in processing time per cycle, which may greatly impair the productivity of the film forming process. is there. Further, in the above-mentioned method, although it is theoretically possible to make the in-plane thickness distribution of the first layer close to the flat distribution, it is difficult to make it a central convex distribution.

Note that when supplying the DCS gas to the wafer 200, the nozzle 249 b, by supplying a large flow rate of N ₂ gas from the 249 c, plane thickness distribution of the first layer, closer from the center concave distribution to flat distribution It is also possible to approach the central convex distribution. By controlling the N ₂ gas in this way, the pressure in the annular space (hereinafter, also simply referred to as “annular space”) in the plan view between the inner wall of the reaction tube 203 and the wafer 200 is reduced to the wafer arrangement. It is greater than the pressure in the region, i.e., the pressure in the space between the wafers 200. As a result, the outflow of DCS gas into the annular space is suppressed, and the amount of DCS gas supplied to the central portion of the wafer 200 is increased. Further, the partial pressure (concentration) of the DCS gas in the annular space decreases, and the amount of DCS gas supplied to the peripheral edge of the wafer 200 decreases. As a result, the in-plane thickness distribution of the first layer is controlled as described above. _{However, depending on the supply timing of the N 2} gas from the nozzles 249b and 249c and the flow rate thereof, the formation rate of the first layer may decrease due to the dilution of the DCS gas, and the productivity of the film forming process may be significantly impaired. There is. These are new issues that have become clear for the first time as a result of diligent research by the inventors.

In the present embodiment, in order to avoid the above-mentioned various problems, the above-mentioned steps A1 and A2 are performed in this order in step A. The details of these steps will be described below.

In step A1, while supplying the DCS gas from the nozzle 249a, the valve 243 d, open the 243 c, gas supply pipe 232 d, 232b, flushed with _{N 2} gas into the 232c, nozzles 249 b, _{N 2} to from the processing chamber 201 249 c Supply gas. _{In this step, the supply of N 2} gas from the nozzles 249b and 249c may not be performed. However, it is preferable to _{supply the N 2} gas from the nozzles 249b and 249c because it is possible to suppress the invasion of the DCS gas into these nozzles. The nozzle 249 b, in order to suppress intrusion of the DCS gas into the 249 c, the nozzle 249 b, the supply of _{N 2} gas from the 249 c, Step A simultaneously, or preferably started before.

_{In step A1, each flow rate (first flow rate) of the N 2} gas supplied from the nozzles 249b and 249c is set to be smaller than the flow rate of the DCS gas supplied from the nozzle 249a. _{Preferably, each flow rate of the N 2} gas supplied from the nozzles 249b and 249c is set so that the total flow rate thereof is smaller than the flow rate of the DCS gas supplied from the nozzle 249a.

_{By setting the flow rate of the N 2} gas supplied from the nozzles 249b and 249c to be small in this way, dilution of the DCS gas supplied from the nozzles 249a in the processing chamber 201 can be suppressed, and the first layer on the wafer 200 can be suppressed. It is possible to proceed with the formation process of one layer at a relatively large formation rate (first rate). _{The flow rate of the N 2} gas supplied from the nozzles 249b and 249c can be set to a predetermined flow rate within the range of, for example, 0 to 500 sccm, respectively. The implementation time of step A1 can be, for example, 1/4 to 1/2 of the implementation time of step A.

In step A, when step A1 is continuously carried out, the formation rate of the first layer changes from the above-mentioned first rate to a second rate smaller than the first rate. Therefore, step A1 is continued, and when the formation rate of the first layer changes from the above-mentioned first rate to the second rate, or after the change, the supply of DCS gas from the nozzle 249a is continued (maintained). in state, MFC 241 d, and control 241c, nozzles 249 b, to start the step A2 to increase the flow rate of _{N 2} gas supplied from the 249 c. When step A1 is continued, the formation rate of the first layer is greatly reduced to reach an inflection point because, as described above, the amount of adsorption sites existing on the wafer 200 is reduced.

_{In step A2, each flow rate (second flow rate) of the N 2} gas supplied from the nozzles 249b and 249c is set so that the total flow rate thereof is larger than the flow rate of the DCS gas supplied from the nozzle 249a. .. Preferably, each flow rate (second flow rate) of the _{N 2} gas supplied from the nozzles 249b and 249c is such that the total flow rate thereof is larger than the total flow rate of the _{DCS gas and the N 2 gas supplied from the nozzle 249a.} Flow rate. _{Further, preferably, each flow rate of the N 2} gas supplied from the nozzles 249b and 249c is larger than the flow rate of the DCS gas supplied from the nozzle 249a. _{More preferably, each flow rate of the N 2} gas supplied from the nozzles 249b and 249c is larger than the total flow rate of the _{DCS gas and the N 2} gas supplied from the nozzle 249a, respectively.

_{By setting the flow rate of the N 2} gas supplied from the nozzles 249b and 249c to be large in this way, the pressure in the above-mentioned annular space can be made larger than the pressure in the space between the wafers 200, and the center of the wafer 200 can be set. The amount of DCS gas supplied to the unit can be increased. It is also possible to reduce the partial pressure of the DCS gas in the annular space and reduce the amount of DCS gas supplied to the peripheral edge of the wafer 200. As a result, the in-plane thickness distribution of the first layer can be brought closer from the central concave distribution to the flat distribution, and further to the central convex distribution. _{The flow rate of the N 2} gas supplied from the nozzles 249b and 249c is set to a predetermined flow rate within the range of, for example, 3000 to 6000 sccm, respectively. The implementation time of step A2 can be, for example, 1/2 to 3/4 of the implementation time of step A. By making the execution time of step A2 longer than the implementation time of step A1, it is possible to increase the degree of the central convex distribution of the in-plane thickness distribution of the first layer.

After the first layer having the desired thickness and in-plane thickness distribution is formed, the valve 243a is closed and the DCS gas supply is stopped. Further, by controlling the MFC 241d and 241c, _{the flow rate of the N 2} gas supplied from the nozzles 249b and 249c is changed from the second flow rate to the first flow rate, or the flow rate is about the same as the flow rate of the _{N 2 gas supplied from the nozzle 249a.} Reduce to. At this time, with the APC valve 244 kept open, the inside of the processing chamber 201 is evacuated by the vacuum pump 246, and the unreacted DCS gas remaining in the processing chamber 201 or the DCS gas after contributing to the formation of the first layer is discharged into the processing chamber. Exclude from within 201. _{The N 2} gas supplied from the nozzles 249a to 249c acts as a purge gas, whereby the inside of the processing chamber 201 is purged (purge step).

[Step B]
After the step A is finished, the wafer 200 in the process chamber 201, i.e., supplying the NH ₃ gas to the first layer formed on the wafer 200.

In this step, the opening / closing control of the valves 243b, 243c to 243e is performed in the same procedure as the opening / closing control of the valves 243a, 243c to 243e in step A1. The _{flow rate of the NH 3} gas is adjusted by the MFC 241b, is supplied into the processing chamber 201 via the nozzle 249b, and is exhausted from the exhaust port 231a. At this time, NH ₃ gas is supplied to the wafer 200.

The supply flow rate of NH ₃ gas is, for example, a predetermined flow rate within the range of 1000 to 10000 sccm. The supply time of NH ₃ gas is, for example, a predetermined time within the range of 1 to 120 seconds, preferably 1 to 60 seconds. _{The supply flow rate of the N 2} gas supplied from each gas supply pipe is, for example, a predetermined flow rate within the range of 0 to 2000 sccm. The pressure in the processing chamber 201 is, for example, a predetermined pressure within the range of 1 to 4000 Pa, preferably 1 to 3000 Pa. By setting the pressure in the processing chamber 201 to such a relatively high pressure band, _{it is possible to thermally activate the NH 3} gas in a non-plasma manner. When the NH ₃ gas is activated by heat and supplied, a relatively soft reaction can occur, and the formation of the second layer, which will be described later, becomes easy. Other processing conditions are the same as those in step A.

By supplying NH ₃ gas to the wafer 200 under the conditions described above, at least a portion of the first layer formed on the wafer 200 is nitrided (reforming). By modifying the first layer, a second layer containing Si and N, that is, a SiN layer is formed on the wafer 200. When forming the second layer, impurities such as Cl contained in the first layer, in the course of the reforming reaction of the first layer by the NH ₃ gas, constitutes a gaseous material containing at least Cl, the processing chamber It is discharged from within 201. That is, impurities such as Cl in the first layer are separated from the first layer by being extracted or removed from the first layer. As a result, the second layer becomes a layer having less impurities such as Cl as compared with the first layer.

After the second layer is formed, closing the valve 243b, to stop the supply of the NH ₃ gas. Then, the same process as the purge step of Step A procedure, by the processing conditions, the processing chamber unreacted or NH ₃ gas and reaction by-products after contributing to the formation of the second layer remaining process chamber 201 into the 201 Exclude from.

[Implemented a predetermined number of times]
By performing the cycles in which steps A and B are performed non-simultaneously, that is, without synchronizing, one or more times (n times), a SiN film having a predetermined composition and a predetermined film thickness can be formed on the wafer 200. The above cycle is preferably repeated a plurality of times. That is, the thickness of the second layer formed when the above cycle is performed once is made thinner than the desired film thickness, and the film thickness of the SiN film formed by laminating the second layer is the desired film thickness. It is preferable to repeat the above cycle a plurality of times until the film becomes thick.

In addition to DCS gas, the raw materials include monochlorosilane (SiH ₃ Cl, abbreviated as MCS) gas, trichlorosilane (SiHCl ₃ , abbreviated as TCS) gas, tetrachlorosilane (SiCl ₄ , abbreviated as STC) gas, and hexachlorodisilane (Si). _{Chlorosilane raw material gas such as 2} Cl ₆ , abbreviated as HCDS) gas and octachlorotrisilane (Si ₃ Cl ₈ , abbreviated as OCTS) gas can be used.

As the reactant _{, in addition to NH 3} gas, for example, hydrogen nitride-based gas such as _{diimide (N 2} H ₂ ) gas, hydrazine (N ₂ H ₄ ) gas, and N ₃ H _{8 gas can be used.}

As the inert gas, in addition to the N ₂ gas, a rare gas such as Ar gas, He gas, Ne gas, and Xe gas can be used.

(After purging-return to atmospheric pressure)
Desired composition on the wafer 200, if desired the thickness of the film is formed, the _{N 2} gas as a purge gas is supplied into the processing chamber 201 from each nozzle 249A～249c, exhausted from the exhaust port 231a. As a result, the inside of the treatment chamber 201 is purged, and the gas and reaction by-products remaining in the treatment chamber 201 are removed from the inside of the treatment chamber 201 (after-purge). After that, the atmosphere in the treatment chamber 201 is replaced with the inert gas (replacement of the inert gas), and the pressure in the treatment chamber 201 is restored to the normal pressure (return to atmospheric pressure).

(Boat unloading and wafer discharge)
The boat elevator 115 lowers the seal cap 219 to open the lower end of the manifold 209. Then, the processed wafer 200 is carried out (boat unloading) from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the boat 217. After the boat is unloaded, the shutter 219s is moved and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). The processed wafer 200 is carried out of the reaction tube 203 and then taken out from the boat 217 (wafer discharge).

(3) Effects of the present embodiment According to the present embodiment, one or more of the following effects can be obtained.

(A) By performing step A2 when supplying DCS gas to the wafer 200, the in-plane film thickness distribution of the SiN film formed on the wafer 200 configured as a bare wafer is set to a central convex distribution. It becomes possible. As a result, when a pattern wafer is used as the wafer 200, a SiN film having a flat distribution can be formed on the wafer 200. _{In step A2, by setting each flow rate of the N 2} gas supplied from the nozzles 249b and 249c to a flow rate larger than the flow rate of the DCS gas supplied from the nozzle 249a, the above-mentioned central convex distribution can be more reliably performed. It will be possible.

It is considered that the in-plane film thickness distribution of the film formed on the wafer 200 depends on the surface area of the wafer 200 due to the so-called loading effect. As the surface area of the wafer 200 to be formed becomes larger, a large amount of raw materials such as DCS gas are consumed at the peripheral portion of the wafer 200, and it becomes difficult to reach the central portion thereof. As a result, the in-plane film thickness distribution of the film formed on the wafer 200 becomes a central concave distribution. According to this embodiment, even when a patterned wafer having a large surface area is used as the wafer 200, the in-plane film thickness distribution of the film formed on the wafer 200 can be corrected from a central concave distribution to a flat distribution. Furthermore, it is possible to freely control the distribution, such as correcting the central convex distribution.

(B) By performing step A1 before performing step A2, dilution of DCS gas can be suppressed at the initial stage of formation of the first layer in which adsorption sites are abundantly present on the wafer 200. This makes it possible to allow the formation of the first layer to proceed at a large formation rate. As a result, it is possible to increase the film formation rate of the SiN film and improve the productivity of the film formation process. _{In step A1, each flow rate of the N 2} gas supplied from the nozzles 249b and 249c is set to a flow rate such that the total flow rate thereof is smaller than the flow rate of the DCS gas supplied from the nozzle 249a. Dilution of DCS gas can be further suppressed, and the above-mentioned effects can be more reliably realized.

(C) By arranging the nozzles 249b and 249c on both sides of the nozzle 249a, the controllability of the in-plane thickness distribution of the first layer, that is, the in-plane film of the SiN film formed on the wafer 200 It is possible to improve the controllability of the thickness distribution.

(D) By arranging the nozzles 249a to 249c so as to face the exhaust port 231a, the controllability of the in-plane thickness distribution of the first layer, that is, the in-plane of the SiN film formed on the wafer 200 It is possible to improve the controllability of the film thickness distribution.

(E) The above-mentioned effect can be similarly obtained when a raw material other than DCS gas is used, when _{a reactant other than NH 3} gas is used, or when an inert gas other than _{N 2 gas is used.} ..

(4) Modification example The film formation step in the present embodiment can be changed as in the modification shown below.

(Modification example 1)
As described above, in step A, when step A1 is continued without performing step A2, the formation rate of the first layer changes from the first rate to the second rate smaller than the first rate. In this modification, step A2 is performed before the formation rate of the first layer changes from the first rate to the second rate, which is smaller than the first rate, preferably before (immediately before) reaching the inflection point. Start.

According to this modification, the start timing of step A2, which acts to bring the in-plane thickness distribution of the first layer closer to the central convex distribution, is advanced, and the in-plane thickness distribution of the first layer tends to be a central concave distribution. By shortening the implementation period of a certain step A1, the in-plane film thickness distribution of the SiN film formed on the wafer 200 can be more reliably made into a central convex distribution.

(Modification 2)
Using, for example, 1,1,2,2-tetrachloro-1,2-dimethyl-disilane _{((CH 3) 2 Si 2} Cl 4, abbreviation: TCDMDS) and alkylhalosilane source gas such as a gas, tris dimethyl aminosilane _{(Si [N (CH 3)} 2] 3 H, abbreviation: 3DMAS) gas or bis diethylamino silane _{(SiH 2 [N (C 2} H 5) 2] 2, abbreviated: BDEAS) an aminosilane material gas such as a gas You may use it. Further, a silane (silicon hydride) raw material gas such as monosilane (SiH ₄ ) gas and disilane (Si ₂ H _{6) gas may be used.}

Further, as the reactant, for example, _{an amine-based gas such as triethylamine ((C 2} H ₅ ) ₃ N, abbreviated as TEA) gas, oxygen (O ₂ ) gas, water vapor (H ₂ O), ozone (O _3). ) Gas, O-containing gas (oxidizer) such as plasma-excited O ₂ gas (O ₂ ^* ), O ₂ gas + hydrogen (H ₂ ) gas, and C such as _{propylene (C 3} H _{6) gas.} A B-containing gas such as a contained gas or a trichloroborane (BCl _{3) gas may be used.}

Then, for example, by the following film forming sequence, a silicon oxynitride film (SiON film), a silicon oxycarbonate film (SiOCN film), a silicon acid carbide film (SiOC film), and a silicon carbon dioxide film (SiCN film) are placed on the wafer 200. ), Silicon borocarbide nitride film (SiBCN film), silicon boronitride film (SiBN film), and silicon oxide film (SiO film) may be formed.

(DCS → NH ₃ → O ₂ ) × n ⇒ SiON
(DCS → TEA → O ₂ ) × n ⇒ SiOC (N)
(DCS → C ₃ H ₆ → NH ₃ ) × n ⇒ SiCN
(DCS → C ₃ H ₆ → NH ₃ → O ₂ ) × n ⇒ SiOCN
(DCS → C ₃ H ₆ → BCl ₃ → NH ₃ ) × n ⇒ SiBCN
(DCS → BCl ₃ → NH ₃ ) × n ⇒ SiBN
(DCS → O ₂ + H ₂ ) × n ⇒ SiO
(3DMAS → O ₃ ) × n ⇒ SiO
(BDEAS → O ₂ ^* ) × n ⇒ SiO

Also in these film forming sequences, the same effects as these can be obtained by performing steps A1 and A2 in the same manner as in the film forming sequence shown in FIG. 4 and the modification 1 at the time of supplying the raw materials. The treatment procedure and treatment conditions for supplying the raw material and the reactant can be the same as those of the film formation sequence and the modification 1 shown in FIG.

<Other Embodiments>
The embodiment of the present invention has been specifically described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof.

In the above-described embodiment, the second nozzle has nozzles 249b and 249c, and they are arranged on both sides of the nozzle 249a as the first nozzle. Not limited to. For example, the second nozzle may have only the nozzle 249b, and the nozzle 249b may be arranged close to or separated from the nozzle 249a. Even in this case, the same effects as these can be obtained by performing steps A1 and A2 in the same manner as in the film forming sequence shown in FIG. 4 and the modified examples 1 and 2 at the time of supplying the raw materials. However, the nozzle arrangement in the above-described embodiment is preferable in that the controllability of the in-plane film thickness distribution of the film formed on the wafer 200 can be improved.

In the above-described embodiment, an example in which steps A1 and A2 are performed at the time of supplying raw materials has been described, but the present invention is not limited to such an embodiment. For example, steps A1 and A2 may be performed when the reactant is supplied instead of when the DCS gas is supplied. In this case, it is possible to control the concentration distribution of N, C, O, B, etc. in the plane of the wafer 200 of the film formed on the wafer 200. Steps A1 and A2 performed when the reactants are supplied can be performed according to the film forming sequence shown in FIG. 4 and the same processing conditions and procedures as those of steps A1 and A2 shown in the first and second modifications.

In the above embodiment, the reactants such as NH ₃ gas, an example has been described is supplied from the nozzle 249 b, the present invention is not limited to such a mode. For example, the reactants may be supplied from both nozzles 249b and 249c. Further, a nozzle different from the nozzles 249a to 249c may be newly provided in the processing chamber 201, and the reactant may be supplied by using the newly provided nozzle. Even in these cases, the same effects as these can be obtained by performing steps A1 and A2 in the same manner as in the film forming sequence shown in FIG. 4 and the modified examples 1 and 2 at the time of supplying the raw materials.

In the above-described embodiment, an example of forming a film containing Si as a main element on a substrate has been described, but the present invention is not limited to such an embodiment. That is, the present invention can also be suitably applied to the case where a film containing a metalloid element such as germanium (Ge) or boron (B) as a main element is formed on the substrate in addition to Si. Further, the present invention relates to titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), yttrium (Y), lantern (La). , Strontium (Sr), aluminum (Al) and the like can also be suitably applied to the case of forming a film containing a metal element as a main element on the substrate.

For example, titanium tetrachloride (TiCl ₄ ) gas or trimethylaluminum (Al (CH ₃ ) ₃ , abbreviation: TMA) gas is used as a raw material, and a titanium nitride film (TiN film) is formed on the substrate by the film forming sequence shown below. ), Titanium oxynitride film (TiON film), Titanium aluminum carbon nitride film (TiAlCN film), Titanium aluminum carbide film (TiAlC film), Titanium carbon nitride film (TiCN film), Titanium oxide film (TIO film), etc. In some cases, the present invention can be preferably applied.

(TiCl ₄ → NH ₃ ) × n ⇒ TiN
(TiCl ₄ → NH ₃ → O ₂ ) × n ⇒ TiON
(TiCl ₄ → TMA → NH ₃ ) × n ⇒ TiAlCN
(TiCl ₄ → TMA) × n ⇒ TiAlC
(TiCl ₄ → TEA) × n ⇒ TiCN
(TiCl ₄ → H ₂ O) × n ⇒ TiO

It is preferable that the recipes used for the substrate processing are individually prepared according to the processing content and stored in the storage device 121c via a telecommunication line or an external storage device 123. Then, when starting the processing, it is preferable that the CPU 121a appropriately selects an appropriate recipe from the plurality of recipes stored in the storage device 121c according to the content of the substrate processing. As a result, it becomes possible to form films having various film types, composition ratios, film qualities, and film thicknesses with good reproducibility with one substrate processing device. In addition, the burden on the operator can be reduced, and the process can be started quickly while avoiding operation mistakes.

The above-mentioned recipe is not limited to the case of newly creating, and may be prepared, for example, by modifying an existing recipe already installed in the substrate processing apparatus. When changing the recipe, the changed recipe may be installed on the substrate processing apparatus via a telecommunication line or a recording medium on which the recipe is recorded. Further, the input / output device 122 included in the existing board processing device may be operated to directly change the existing recipe already installed in the board processing device.

In the above-described embodiment, an example in which the first and second nozzles are provided in the processing chamber along the inner wall of the reaction tube has been described. However, the present invention is not limited to the above-described embodiment. For example, as shown in FIG. 6A showing the cross-sectional structure of the vertical processing furnace, a buffer chamber is provided on the side wall of the reaction tube, and the first and second nozzles having the same configuration as those of the above-described embodiment are provided in the buffer chamber. , The arrangement may be the same as that of the above-described embodiment. FIG. 6A shows an example in which a buffer chamber for supply and a buffer chamber for exhaust are provided on the side wall of the reaction tube, and the buffer chambers are arranged at positions facing each other with the wafer interposed therebetween. Further, FIG. 6A shows an example in which the supply buffer chamber is divided into a plurality of (three) spaces and each nozzle is arranged in each space. The arrangement of the three spaces in the buffer chamber is the same as the arrangement of the first and second nozzles. Further, for example, as shown in FIG. 6B, the cross-sectional structure of the vertical processing furnace is provided, a buffer chamber is provided in the same arrangement as in FIG. 6A, a first nozzle is provided in the buffer chamber, and processing in this buffer chamber is provided. A second nozzle may be provided along the inner wall of the reaction tube while sandwiching the communication portion with the chamber from both sides. The configurations other than the reaction tubes described in FIGS. 6 (a) and 6 (b) are the same as the configurations of each part of the processing furnace shown in FIG. Even when these processing furnaces are used, the same effects as those in the above-described embodiment can be obtained.

In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes a plurality of substrates at one time has been described. The present invention is not limited to the above-described embodiment, and can be suitably applied to, for example, a case where a film is formed by using a single-wafer type substrate processing apparatus that processes one or several substrates at a time. Further, in the above-described embodiment, an example of forming a film by using a substrate processing apparatus having a hot wall type processing furnace has been described. The present invention is not limited to the above-described embodiment, and can be suitably applied to the case where a film is formed by using a substrate processing apparatus having a cold wall type processing furnace.

Even when these substrate processing devices are used, the film can be formed under the same sequence and processing conditions as those of the above-described embodiments and modifications, and the same effects as these can be obtained.

In addition, the above-described embodiments and modifications can be used in combination as appropriate. The processing procedure and processing conditions at this time can be, for example, the same as the processing procedure and processing conditions of the above-described embodiment.

The SiN film or the like formed by the methods described in the above-described embodiments and modifications can be widely used as an insulating film, a spacer film, a mask film, a charge storage film, a stress control film, and the like. In recent years, with the miniaturization of semiconductor devices, the demand for in-plane film thickness uniformity for the film formed on the wafer has become stricter. The present invention, which is capable of forming a film having a flat distribution on a pattern wafer in which a high-density pattern is formed on the surface, is considered to be very useful as a technique for meeting this demand.

Hereinafter, the experimental results supporting the effects obtained in the above-described embodiment will be described.

As an example, using the substrate processing apparatus shown in FIG. 1, SiN films were formed on a plurality of wafers by the film forming sequence shown in FIG. As the wafer, a bare wafer having no uneven structure formed on the surface and a pattern wafer having an uneven structure formed on the surface were used. As the pattern wafer, a wafer in which the surface area of the main surface (base of the film forming treatment) is 20 to 25 times the surface area of the main surface of the bare wafer is used. The other processing conditions were predetermined conditions within the processing condition range described in the above-described embodiment.

As Comparative Example 1, using the substrate processing apparatus shown in FIG. 1, a film forming sequence in which a step A of supplying DCS gas to a wafer and a step B of supplying _{NH 3 gas to a wafer are alternately repeated.} , SiN films were formed on each of a plurality of wafers. However, in Comparative Example 1, only step A1 was performed while step A was performed, and step A2 was not performed. Step A1 was carried out from the start to the end of step A. Other processing conditions were the same as in the examples.

As Comparative Example 2, using the substrate processing apparatus shown in FIG. 1, a film forming sequence in which a step A of supplying DCS gas to a wafer and a step B of supplying _{NH 3 gas to a wafer are alternately repeated.} , SiN films were formed on each of a plurality of wafers. However, in Comparative Example 2, only step A2 was performed while step A was performed, and step A1 was not performed. Step A2 was carried out from the start to the end of step A. Other processing conditions were the same as in the examples.

Then, the in-plane film thickness distribution of the SiN films formed in Examples and Comparative Examples 1 and 2 was measured, respectively. 7 (a) to 7 (c) show the measurement results of Examples, FIGS. 8 (a) to 8 (c) show the measurement results of Comparative Example 1, and FIGS. 9 (a) to 9 (c) show the measurement results. Shows the measurement results of Comparative Example 2, respectively. In each figure, Top, Center, and Bottom indicate the position of the wafer in the wafer arrangement region. The vertical axis of each figure shows the film thickness [Å], and the horizontal axis shows the distance [mm] from the center of the wafer at the measurement position. In the figure, the ■ mark shows the measurement result of the SiN film formed on the bare wafer, and the ◇ mark shows the measurement result of the SiN film formed on the pattern wafer.

According to FIGS. 7 (a) to 7 (c), it can be seen that the in-plane film thickness distributions of the SiN films formed on the bare wafer are all centrally convex. Further, it can be seen that the in-plane film thickness distribution of the SiN film formed on the pattern wafer has a relatively gentle central convex distribution. That is, by carrying out A1 and A2 in this order in step A as in the embodiment, the in-plane film thickness distribution of the SiN film formed on the pattern wafer can be made closer to a flat distribution, for example, relatively gentle. It can be seen that the central convex distribution can be obtained.

According to FIGS. 8 (a) to 8 (c), the in-plane film thickness distribution of the SiN film formed on the bare wafer has a weak central convex distribution or a distribution close to a flat distribution. You can see that. Further, it can be seen that the in-plane film thickness distribution of the SiN film formed on the pattern wafer has a central concave distribution. That is, when step A2 is not performed in step A as in Comparative Example 1, the in-plane film thickness distribution of the SiN film formed on the pattern wafer is set to a flat distribution or a central convex distribution. It turns out to be difficult.

According to FIGS. 9 (a) to 9 (c), it can be seen that the in-plane film thickness distributions of the SiN films formed on the bare wafer are all centrally convex. Further, it can be seen that the in-plane film thickness distribution of the SiN film formed on the pattern wafer has a relatively gentle central convex distribution, although the outer peripheral thickness is partially formed in Top. That is, as in Comparative Example 2, by carrying out step A2 in step A, the in-plane film thickness distribution of the SiN film formed on the pattern wafer is brought closer to a flat distribution, for example, a relatively gentle central convexity. It can be seen that it can be a distribution. However, it can be seen that the SiN films formed in Comparative Example 2 are all thinner than the SiN films formed in Examples. It is considered that this is because the DCS gas was diluted immediately after the start of the step A and the film formation rate was lowered because the step A1 was not performed before the step A2. That is, if step A1 is not performed before step A2 is performed as in Comparative Example 2, it is difficult to improve the productivity of the film forming process as in Example 2.

The SiN film formed on the bare wafer of Comparative Example 2 has poor film thickness uniformity (hereinafter, also referred to as WtW) between the wafers as compared with the SiN film formed on the bare wafer of Comparative Example 1. I understand. On the other hand, it can be seen that the SiN film formed on the pattern wafer of Comparative Example 2 has a better WtW than the SiN film formed on the pattern wafer of Comparative Example 1. That is, in Comparative Example 2, even if the WtW of the SiN film formed on the bare wafer is improved, it is difficult to improve the WtW of the SiN film formed on the pattern wafer so as to follow the WtW. It turns out that there is. As described above, in Comparative Example 2, the tendency of WtW of the SiN film formed on the bare wafer and the pattern wafer may be inconsistent, which is inconvenient for product management. Become.

Further, in the SiN film formed on the pattern wafer of Comparative Example 2, the degree of central convex distribution differs greatly among Top, Center, and Bottom, the degree is relatively small in Top, and the degree is relatively small in Bottom. Can be seen to be relatively large. However, it is preferable that the degree of the central convex distribution is originally uniform among Top, Center, and Bottom. In Comparative Example 2, even if the tendency of the central convex distribution of the SiN film formed on the bare wafer is aligned among Top, Center, and Bottom, the central convex distribution of the SiN film formed on the pattern wafer has the same tendency. This is difficult to do, which is inconvenient for product management.

On the other hand, in the examples, it is possible to solve these problems of Comparative Example 2.

For example, in the embodiment, by improving the WtW of the SiN film formed on the bare wafer, it is possible to improve the WtW of the SiN film formed on the pattern wafer so as to follow the WtW. That is, in the embodiment, it is possible to match the tendency of the in-plane film thickness distribution between the SiN film formed on the bare wafer and the SiN film formed on the pattern wafer. This is convenient for product management.

Further, in the embodiment, by changing the in-plane film thickness distribution of the SiN film formed on the bare wafer, the in-plane film thickness distribution of the SiN film formed on the pattern wafer is set between Top, Center, and Bottom. Can be changed evenly with. That is, in the embodiment, by improving the degree of the central convex distribution of the SiN film formed on the bare wafer, the degree of the central convex distribution of the SiN film formed on the pattern wafer is set between Top, Center, and Bottom. Can be improved evenly. This is also convenient for product management.

In addition, in FIGS. 7A to 7C, the case where the film thickness distribution of the SiN film formed on the pattern wafer is a gentle central convex distribution is illustrated, but the present invention has such an embodiment. Not limited. For example, in the embodiment, the film thickness distribution of the SiN film formed on the pattern wafer is made flat by setting the flow rate (second flow rate) of the _{N 2 gas supplied in step A2 to a slightly lower flow rate side.} Is also possible. That is, the film thickness distribution of the SiN film can be made flat by appropriately increasing / decreasing (adjusting) the flow rate (second flow rate) of the _{N 2} gas supplied in step A2 according to the surface area of the wafer. is there. For example, when the surface area of the pattern wafer is relatively small, the second flow rate is set small, and when the surface area of the pattern wafer is relatively large, the second flow rate is set large. That is, by adjusting the magnitude of the second flow rate according to the surface area of the wafer, it is possible to make the film thickness distribution of the SiN film formed on the wafer flat.

<Preferable Aspect of the Present Invention>
Hereinafter, preferred embodiments of the present invention will be added.

(Appendix 1)
According to one aspect of the invention
(A) A step of forming the first layer by supplying the raw material to the substrate from the first nozzle, and
(B) A step of forming a second layer by supplying a reactant to the substrate from a second nozzle different from the first nozzle.
It has a step of forming a film on the substrate by performing a cycle of performing the above non-simultaneously a predetermined number of times.
In (a) above,
(A-1) A step of supplying the inert gas from the second nozzle at a first flow rate smaller than the flow rate of the raw material while the raw material is supplied from the first nozzle.
(A-2) A step of supplying the inert gas from the second nozzle at a second flow rate larger than the flow rate of the raw material while the raw material is being supplied from the first nozzle.
A method for manufacturing a semiconductor device or a method for processing a substrate is provided.

(Appendix 2)
The method according to Appendix 1, preferably.
In (a-1), when the formation rate of the first layer changes from the first rate to a second rate smaller than the first rate, and the formation rate of the first layer changes to the second rate. Alternatively, after the change, the above (a-2) is started. That is, when the formation rate of the first layer is the first rate, the above (a-2) is not carried out.

(Appendix 3)
The method according to Appendix 1, preferably.
When the (a-1) is continued without carrying out the (a-2), the formation rate of the first layer changes from the first rate to the second rate smaller than the first rate, and the above. (A-2) is started before the formation rate of the first layer changes to the second rate.

(Appendix 4)
The method according to any one of Supplementary notes 1 to 3, preferably.
In (a-2), the inert gas is supplied together with the raw material from the first nozzle.
The second flow rate is made larger than the total flow rate of the raw material and the inert gas supplied from the first nozzle.

(Appendix 5)
The method according to any one of Supplementary notes 1 to 4, preferably.
The second nozzle has a plurality of nozzles, and they are arranged on both sides of the first nozzle.

(Appendix 6)
The method according to Appendix 5, preferably.
In (a-1), the flow rate of the respective inert gas supplied from each of the plurality of nozzles is made smaller than the flow rate of the raw material.

(Appendix 7)
The method according to Appendix 5 or 6, preferably.
In (a-2), the flow rate of each inert gas supplied from each of the plurality of nozzles is made larger than the flow rate of the raw material.

(Appendix 8)
The method according to any one of Appendix 5 to 7, preferably.
In (a-2), the inert gas is supplied together with the raw material from the first nozzle.
The flow rate of each inert gas supplied from each of the plurality of nozzles is made larger than the total flow rate of the raw material and the inert gas supplied from the first nozzle.

(Appendix 9)
According to another aspect of the invention
A processing room where processing is performed on the substrate, and
A raw material supply system that supplies raw materials from the first nozzle to the substrate in the processing chamber,
A reactant supply system that supplies a reactant to a substrate in the processing chamber from a second nozzle different from the first nozzle.
An inert gas supply system that supplies the inert gas to the processing chamber from at least one of the first nozzle and the second nozzle.
In the processing chamber, (a) a process of forming a first layer by supplying a raw material from the first nozzle to the substrate, and (b) supplying a reactant to the substrate from the second nozzle. By performing the process of forming the second layer and the non-simultaneous cycle for forming the second layer a predetermined number of times, the process of forming a film on the substrate is performed. In a state where the raw material is supplied from the nozzle, a process of supplying the inert gas from the second nozzle at a first flow rate smaller than the flow rate of the raw material, and (a-2) the raw material is supplied from the first nozzle. In this state, the raw material supply system, the reactant supply system, and the non-reactant so that the process of supplying the inert gas from the second nozzle at a second flow rate larger than the flow rate of the raw material is performed in this order. A control unit configured to control the active gas supply system and
A substrate processing apparatus having the above is provided.

(Appendix 10)
According to yet another aspect of the invention.
(A) A procedure for forming the first layer by supplying a raw material from the first nozzle to the substrate in the processing chamber of the substrate processing apparatus.
(B) A procedure for forming a second layer by supplying a reactant from a second nozzle different from the first nozzle to the substrate in the processing chamber.
The procedure for forming a film on the substrate by performing the cycle of performing the above non-simultaneously a predetermined number of times, and
In (a) above
(A-1) A procedure in which the raw material is supplied from the first nozzle and the inert gas is supplied from the second nozzle at a first flow rate smaller than the flow rate of the raw material.
(A-2) A procedure in which the raw material is supplied from the first nozzle and the inert gas is supplied from the second nozzle at a second flow rate larger than the flow rate of the raw material.
And the procedure to do in this order
A program for causing the substrate processing apparatus to execute the program by a computer, or a computer-readable recording medium on which the program is recorded is provided.

200 wafers (board)
249a nozzle (first nozzle)
249b nozzle (second nozzle)
249c nozzle (second nozzle)

Claims (12)

(A) A step of forming the first layer by supplying the raw material to the substrate from the first nozzle, and
(B) A step of forming a second layer by supplying a reactant to the substrate from a second nozzle different from the first nozzle.
It has a step of forming a film on the substrate by performing a cycle of performing the above non-simultaneously a predetermined number of times.
In (a) above,
(A-1) A step of supplying the inert gas from the second nozzle at a first flow rate smaller than the flow rate of the raw material while the raw material is supplied from the first nozzle.
(A-2) A step of supplying the inert gas from the second nozzle at a second flow rate larger than the flow rate of the raw material while the raw material is being supplied from the first nozzle.
In this order,
When the (a-1) is continued without carrying out the (a-2), the formation rate of the first layer changes from the first rate to the second rate smaller than the first rate. Manufacture of a semiconductor device in which the above (a) is performed under the conditions, and the above (a-2) is started before, when, or after the formation rate of the first layer changes to the second rate. Method. The method for manufacturing a semiconductor device according to claim 1, wherein the (a-2) is started immediately before the formation rate of the first layer changes to the second rate. In (a-2), the inert gas is supplied from the first nozzle together with the raw material, and the second flow rate is higher than the total flow rate of the raw material and the inert gas supplied from the first nozzle. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the size is increased. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the second nozzle has a plurality of nozzles, and these are arranged on both sides of the first nozzle. The method for manufacturing a semiconductor device according to claim 4, wherein in (a-1), the flow rate of each inert gas supplied from each of the plurality of nozzles of the second nozzle is smaller than the flow rate of the raw material. .. In (a-2), the semiconductor device according to claim 4 or 5, wherein the flow rate of each inert gas supplied from each of the plurality of nozzles of the second nozzle is larger than the flow rate of the raw material. Production method. In (a-2), the inert gas is supplied together with the raw material from the first nozzle.
Claims 4 to 6 in which the flow rate of each inert gas supplied from each of the plurality of nozzles of the second nozzle is made larger than the total flow rate of the raw material and the inert gas supplied from the first nozzle. The method for manufacturing a semiconductor device according to any one of the items. In (a), the raw material and the inert gas supplied from the first nozzle and the second nozzle are provided at positions facing the first nozzle with the substrate sandwiched in a plan view. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, which is more exhausted. In (a), the raw material and the inert gas supplied from the first nozzle and the second nozzle are located at positions facing the first nozzle and the second nozzle with the substrate sandwiched in a plan view. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the exhaust is exhausted from the provided exhaust port. The method for manufacturing a semiconductor device according to any one of claims 1 to 9, wherein the raw material contains halosilane. A processing room where processing is performed on the substrate, and
A raw material supply system that supplies raw materials from the first nozzle to the substrate in the processing chamber,
A reactant supply system that supplies a reactant to a substrate in the processing chamber from a second nozzle different from the first nozzle.
An inert gas supply system that supplies the inert gas to the processing chamber from at least one of the first nozzle and the second nozzle.
In the processing chamber, (a) a process of forming a first layer by supplying a raw material from the first nozzle to the substrate, and (b) supplying a reactant to the substrate from the second nozzle. By performing the process of forming the second layer and the non-simultaneous cycle for forming the second layer a predetermined number of times, the process of forming a film on the substrate is performed. In a state where the raw material is supplied from the nozzle, a process of supplying the inert gas from the second nozzle at a first flow rate smaller than the flow rate of the raw material, and (a-2) the raw material is supplied from the first nozzle. In this state, the process of supplying the inert gas at a second flow rate larger than the flow rate of the raw material from the second nozzle is performed in this order, and the above (a-1) and the above (a-2) are carried out. The above (a) is performed under the condition that the formation rate of the first layer changes from the first rate to the second rate, which is smaller than the first rate, when the formation rate of the first layer is continued without the above (a-2). ) To start before, when, or after the formation rate of the first layer changes to the second rate, the raw material supply system, the reactant supply system, and the inert gas. A control unit configured to control the supply system and
Substrate processing equipment with. (A) A procedure for forming the first layer by supplying a raw material from the first nozzle to the substrate in the processing chamber of the substrate processing apparatus.
(B) A procedure for forming a second layer by supplying a reactant from a second nozzle different from the first nozzle to the substrate in the processing chamber.
The procedure for forming a film on the substrate by performing the cycle of performing the above non-simultaneously a predetermined number of times, and
In (a) above
(A-1) A procedure in which the raw material is supplied from the first nozzle and the inert gas is supplied from the second nozzle at a first flow rate smaller than the flow rate of the raw material.
(A-2) A procedure in which the raw material is supplied from the first nozzle and the inert gas is supplied from the second nozzle at a second flow rate larger than the flow rate of the raw material.
And the procedure to do in this order
In the above (a-1), when the above (a-2) is continued without being carried out, the formation rate of the first layer changes from the first rate to the second rate smaller than the first rate. A procedure in which the above (a) is performed under the conditions, and the above (a-2) is started before, when, or after the formation rate of the first layer changes to the second rate.
A program that causes the board processing apparatus to execute the above.

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