Method of manufacturing semiconductor device, substrate processing apparatus, and method of processing substrate

There is provided a technique that includes forming a film on a substrate by performing a cycle a predetermined number of times, the cycle including: (a) supplying a precursor gas to the substrate in a process container of a substrate processing apparatus via a first pipe made of metal; (b) supplying an oxygen-containing gas to the substrate in the process container via a second pipe made of metal, wherein a fluorine-containing layer is continuously formed on an inner surface of the second pipe; and (c) supplying a nitrogen-and-hydrogen-containing gas to the substrate in the process container via the second pipe.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-095087, filed on May 21, 2019, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a method of manufacturing a semiconductor device, a substrate processing apparatus, and a recording medium.

BACKGROUND

In a related art, as a process of manufacturing a semiconductor device, a process of processing a substrate in a process container is often carried out.

SUMMARY

The present disclosure provides some embodiments of a technique capable of improving a quality of substrate processing performed in a process container.

According to one or more embodiments of the present disclosure, there is provided a technique that includes forming a film on a substrate by performing a cycle a predetermined number of times, the cycle including: (a) supplying a precursor gas to the substrate in a process container of a substrate processing apparatus via a first pipe made of metal; (b) supplying an oxygen-containing gas to the substrate in the process container via a second pipe made of metal, wherein a fluorine-containing layer is continuously formed on an inner surface of the second pipe; and (c) supplying a nitrogen-and-hydrogen-containing gas to the substrate in the process container via the second pipe.

DETAILED DESCRIPTION

One or More Embodiments of the Present Disclosure

One or more embodiments of the present disclosure will now be mainly described with reference toFIGS. 1 to 6.

(1) Configuration of Substrate Processing Apparatus

As illustrated inFIG. 1, a process furnace202includes a heater207as a heating mechanism (a temperature adjustment part). The heater207has a cylindrical shape and is supported by a support plate so as to be vertically installed. The heater207also functions as an activation mechanism (an excitation part) configured to thermally activate (excite) gas.

A reaction tube203is disposed inside the heater207to be concentric with the heater207. The reaction tube203is made of, for example, a heat resistant material such as quartz (SiO2), silicon carbide (SiC), or the like, and has a cylindrical shape with its upper end closed and its lower end opened. A manifold209is disposed below the reaction tube203in a concentric relationship with the reaction tube203. The manifold209is made of, for example, a metal material such as stainless steel (SUS), and has a cylindrical shape with its upper and lower ends opened. The upper end portion of the manifold209engages with the lower end portion of the reaction tube203so as to support the reaction tube203. An O-ring220aserving as a seal member is installed between the manifold209and the reaction tube203. Similar to the heater207, the reaction tube203is vertically installed. A process container (reaction container) mainly includes the reaction tube203and the manifold209. A process chamber201is formed in a hollow cylindrical portion of the process container. The process chamber201is configured to accommodate wafers200as substrates. Processing on the wafers200is performed in the process chamber201.

Nozzles249aand249bas first and second suppliers are installed in the process chamber201so as to penetrate a sidewall of the manifold209. The nozzles249aand249bare also referred to as a first nozzle and a second nozzle, respectively. The nozzles249aand249bare each made of, for example, a heat resistant material which is a non-metallic material such as quartz, SiC, or the like. The nozzles249aand249bare configured as common nozzles used for supplying plural kinds of gases, respectively.

Gas supply pipes232aand232bas first and second pipes are connected to the nozzles249aand249b,respectively. The gas supply pipes232aand232bare configured as common pipes used for supplying plural kinds of gases, respectively. Mass flow controllers (MFCs)241aand241b,which are flow rate controllers (flow rate control parts), and valves243aand243b,which are opening/closing valves, are installed in the gas supply pipes232aand232bsequentially from upstream sides of gas flow, respectively. Gas supply pipes232c,232eand232hare respectively connected to the gas supply pipe232aat a downstream side of the valve243a.MFCs241c,241eand241hand valves243c,243eand243hare installed in the gas supply pipes232c,232eand232hsequentially from upstream sides of gas flow, respectively. Gas supply pipes232d,232f,232gand232iare respectively connected to the gas supply pipe232bat a downstream side of the valve243b.MFCs241d,241f,241gand241iand valves243d,243f,243gand243iare installed in the gas supply pipes232d,232f,232gand232isequentially from upstream sides of gas flow, respectively.

The gas supply pipes232ato232iare made of a metal material containing iron (Fe) and nickel (Ni). The material of the gas supply pipes232ato232imay contain Fe, Ni, and chromium (Cr), or may contain Fe, Ni, Cr, and molybdenum (Mo). That is, as the material of the gas supply pipes232ato232i,it may be possible to suitably use, for example, Hastelloy (registered trademark) that has improved heat resistance and corrosion resistance by adding Fe, Mo, Cr, or the like to Ni, Inconel (registered trademark) with enhanced heat resistance and corrosion resistance by adding Fe, Cr, niobium (Nb), Mo, or the like to Ni, or the like, as well as SUS. Furthermore, the material of the manifold209described above and materials of a seal cap219, a rotary shaft255, and an exhaust pipe231as described hereinbelow may be similar to those of the gas supply pipes232ato232i.

As illustrated inFIG. 2, the gas supply pipe232baccording to the present embodiments includes a gas supply pipe232b-1as a first part and a gas supply pipe232b-2as a second part. The gas supply pipe232b-1includes a metal material containing Fe, Ni, and Cr as a first material. As the material of the gas supply pipe232b-1, it may be possible to suitably use SUS or the like. The gas supply pipe232b-2includes a metal material containing Fe, Ni, Cr, and Mo as a second material. As the material of the gas supply pipe232b-2, it may be possible to suitably use Hastelloy or the like.

A fluorine (F)-containing layer is formed on respective inner surfaces of the gas supply pipes232b-1and232b-2. The formation of the F-containing layer on the inner surface of the gas supply pipe232b-1and the formation of the F-containing layer on the inner surface of the gas supply pipe232b-2may be performed separately under different conditions, with the gas supply pipe232bseparated into the gas supply pipe232b-1and the gas supply pipe232b-2. Then, the gas supply pipes232b-1and232b-2in which the F-containing layer is formed on the respective inner surfaces separately under different conditions are installed in a substrate processing apparatus. In this operation, the gas supply pipe232b-1and the gas supply pipe232b-2are connected (coupled) so as to be in a fixed state.

When the gas supply pipes232b-1and232b-2are installed in the substrate processing apparatus, the gas supply pipe232b-1is disposed at a position farther from the process container than the gas supply pipe232b-2and the gas supply pipe232b-2is disposed at a position closer to the process container than the gas supply pipe232b-1. That is, the gas supply pipe232b-2made of Hastelloy, which is higher in heat resistance and corrosion resistance than SUS, is used as the pipe closer to the process container which may be easily affected by heat from the process container. Furthermore, the gas supply pipe232b-1made of SUS, which is lower in heat resistance and corrosion resistance than Hastelloy, is used as the pipe farther from the process container which may be hardly affected by heat from the process container.

That is, the F-containing layer is formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2by supplying a F-containing gas to the respective inner surfaces of the gas supply pipes232b-1and232b-2before installing the gas supply pipes232b-1and232b-2in the substrate processing apparatus. As the F-containing gas, it may be possible to use, for example, fluorine (F2) gas. A method for forming the F-containing layer will be described later.

As illustrated inFIG. 3, each of the nozzles249aand249bis disposed in a space with an annular shape (in a plane view) between an inner wall of the reaction tube203and the wafers200such that the nozzles249aand249bextend upward along an arrangement direction of the wafers200from a lower portion of the inner wall of the reaction tube203to an upper portion of the inner wall of the reaction tube203. Specifically, each of the nozzles249aand249bis installed at a lateral side of a wafer arrangement region in which the wafers200are arranged, namely in a region which horizontally surrounds the wafer arrangement region, along the wafer arrangement region. Gas supply holes250aand250bfor supplying gas are installed on side surfaces of the nozzles249aand249b,respectively. Each of the gas supply holes250aand250bis opened toward the center of the wafers200in a plan view, to allow the gas to be supplied toward the wafers200. The gas supply holes250aand250bmay be installed in a plural number between the lower portion of the reaction tube203and the upper portion of the reaction tube203.

A precursor gas, for example, a halosilane-based gas which contains silicon (Si) as a main element (predetermined element) constituting a film and a halogen element, is supplied from the gas supply pipe232ainto the process chamber201via the MFC241a,the valve243a, and the nozzle249a.The precursor gas refers to a gaseous precursor, for example, gas obtained by vaporizing a precursor which remains in a liquid state under a room temperature and an atmospheric pressure, or a precursor which remains in a gas state under a room temperature and an atmospheric pressure. The halosilane refers to a silane including a halogen group. The halogen group includes a chloro group, a fluoro group, a bromo group, an iodo group, and the like. That is, the halogen group includes a halogen element such as chlorine (Cl), fluorine (F), bromine (Br), iodine (I), or the like. As the halosilane-based gas, it may be possible to use, for example, a precursor gas containing Si and Cl, i.e., a chlorosilane-based gas. The chlorosilane-based gas acts as a Si source. As the chlorosilane-based gas, it may be possible to use, for example, hexachlorodisilane (Si2Cl6, abbreviation: HCDS) gas. The HCDS gas is a gas containing an element (Si) which becomes solid alone under the aforementioned processing conditions, i.e., a gas which can deposit a film alone under the aforementioned processing conditions.

An oxygen (O)-containing gas as a reaction gas is supplied from the gas supply pipe232binto the process chamber201via the MFC241b,the valve243b,and the nozzle249b.As the O-containing gas, it may be possible to use, for example, oxygen (O2) gas.

A carbon (C)-containing gas as a reaction gas is supplied from the gas supply pipe232cinto the process chamber201via the MFC241c,the valve243c,the gas supply pipe232a,and the nozzle249a.As the C-containing gas, it may be possible to use, for example, propylene (C3H6) gas which is a hydrocarbon-based gas.

A nitrogen (N)-and-hydrogen (H)-containing gas as a reaction gas is supplied from the gas supply pipe232dinto the process chamber201via the MFC241d,the valve243d,the gas supply pipe232b,and the nozzle249b.As the N-and-H-containing gas, it may be possible to use, for example, ammonia (NH3) gas which is a hydrogen nitride-based gas.

A cleaning gas is supplied from the gas supply pipes232eand232finto the process chamber201via the MFCs241eand241f,the valves243eand243f,the gas supply pipes232aand232b,and the nozzles249aand249b,respectively. The cleaning gas acts as a cleaning gas in each of chamber cleaning, first nozzle cleaning, and second nozzle cleaning, which are initial cleanings as described hereinbelow. As the cleaning gas, it may be possible to use, for example, chlorine trifluoride (ClF3) gas.

A nitrogen oxide-based gas as an additive gas is supplied from the gas supply pipe232ginto the process chamber201via the MFC241g,the valve243g,the gas supply pipe232b,and the nozzle249b.The nitrogen oxide-based gas alone does not show a cleaning effect, but acts to improve the cleaning effect of the cleaning gas by reacting with the cleaning gas in the chamber cleaning as described hereinbelow to generate active species such as, e.g., fluorine radicals, nitrosyl halide compounds, or the like. As the nitrogen oxide-based gas, it may be possible to use, for example, nitrogen monoxide (NO) gas.

An inert gas, for example, nitrogen (N2) gas, is supplied from the gas supply pipes232hand232iinto the process chamber201via the MFC241hand241i,the valves243hand243i,the gas supply pipes232aand232b,and the nozzles249aand249b,respectively. The N2gas acts as a purge gas, a carrier gas, a dilution gas, or the like.

A precursor gas supply system mainly includes the gas supply pipe232a,the MFC241a, the valve243a,and the nozzle249a.An O-containing gas supply system mainly includes the gas supply pipe232b,the MFC241b,the valve243b,and the nozzle249b.A C-containing gas supply system mainly includes the gas supply pipe232c,the MFC241c,the valve243c,the gas supply pipe232a,and the nozzle249a.A N-and-H-containing gas supply system mainly includes the gas supply pipe232d,the MFC241d,the valve243d,the gas supply pipe232b,and the nozzle249b.A cleaning gas supply system mainly includes the gas supply pipes232eand232f,the MFCs241eand241f,and the valves243eand243f.The cleaning gas supply system may include the gas supply pipes232aand232band the nozzles249aand249b.An additive gas supply system mainly includes the gas supply pipe232g,the MFC241g,the valve243g,the gas supply pipe232b,and the nozzle249b.An inert gas supply system mainly includes the gas supply pipes232hand232i,the MFCs241hand241i,the valves243hand243i,the gas supply pipes232aand232b,and the nozzles249aand249b.As described above, the substrate processing apparatus according to the present embodiments does not include a F2gas supply system for supplying F2gas into the process container. That is, the substrate processing apparatus according to the present embodiments includes no F2gas supply system.

One or all of various supply systems described above may be configured as an integrated-type supply system248in which the valves243ato243i,the MFCs241ato241i,and the like are integrated. The integrated-type supply system248is connected to each of the gas supply pipes232ato232iso that a supply operation of various kinds of gases into the gas supply pipes232ato232i,i.e., opening/closing operation of the valves243ato243i,a flow rate adjustment operation by the MFCs241ato241i,or the like, is controlled by a controller121which will be described later. The integrated-type supply system248is configured as an integral type or detachable-type integrated unit, and may be attached to and detached from the gas supply pipes232ato232ior the like, so as to perform maintenance, replacement, expansion, or the like of the integrated-type supply system248, on an integrated unit basis.

An exhaust port231aconfigured to exhaust an internal atmosphere of the process chamber201is installed below a sidewall of the reaction tube203. The exhaust port231amay be installed from a lower portion of the sidewall of the reaction tube203to an upper portion thereof, i.e., along the wafer arrangement region. An exhaust pipe231is connected to the exhaust port231a.A vacuum pump246as a vacuum exhaust device is connected to the exhaust pipe231via a pressure sensor245as a pressure detector (pressure detection part) which detects an internal pressure of the process chamber201and an auto pressure controller (APC) valve244as a pressure regulator (pressure regulation part). The APC valve244is configured to perform or stop a vacuum exhaust of the interior of the process chamber201by opening or closing the valve while operating the vacuum pump246and is configured to adjust the internal pressure of the process chamber201by adjusting an opening degree of the valve based on pressure information detected by the pressure sensor245while operating the vacuum pump246. An exhaust system mainly includes the exhaust pipe231, the APC valve244and the pressure sensor245. The exhaust system may include the vacuum pump246.

The seal cap219, which serves as a furnace opening cover configured to hermetically seal a lower end opening of the manifold209, is installed under the manifold209. The seal cap219is made of a metal material such as, e.g., stainless steel (SUS) or the like, and is formed in a disc shape. An O-ring220b,which is a seal member making contact with the lower end portion of the manifold209, is installed on an upper surface of the seal cap219. A rotation mechanism267configured to rotate a boat217, which will be described later, is installed under the seal cap219. A rotary shaft255of the rotation mechanism267, which penetrates the seal cap219, is connected to the boat217. The rotation mechanism267is configured to rotate the wafers200by rotating the boat217. The seal cap219is configured to be vertically moved up or down by a boat elevator115which is an elevator mechanism installed outside the reaction tube203. The boat elevator115is configured as a transfer device (transfer mechanism) which loads or unloads (transfers) the wafers200into or from (out of) the process chamber201by moving the seal cap219up or down. A shutter219sas a furnace opening cover capable of hermetically seal the lower end opening of the manifold209while moving the seal cap219down to unload the boat217from the interior of the process chamber201is installed under the manifold209. The shutter219sis made of a metal material such as, e.g., stainless steel (SUS) or the like, and is formed in a disc shape. An O-ring220cas a seal member making contact with the lower end portion of the manifold209is installed on an upper surface of the shutter219s.The opening/closing operation (such as an up/down movement operation, a rotational movement operation, or the like) of the shutter219sis controlled by a shutter-opening/closing mechanism115s.

The boat217serving as a substrate support is configured to support a plurality of wafers200, e.g., 25 to 200 wafers, in such a state that the wafers200are arranged in a horizontal posture and in multiple stages along a vertical direction with the centers of the wafers200aligned with one another. As such, the boat217is configured to arrange the wafers200to be spaced apart from each other. The boat217is made of a heat resistant material such as quartz or SiC. Heat-insulating plates218made of a heat resistant material such as quartz or SiC are installed below the boat217in multiple stages.

A temperature sensor263serving as a temperature detector is installed in the reaction tube203. Based on temperature information detected by the temperature sensor263, a state of supplying electric power to the heater207is adjusted such that the interior of the process chamber201has a desired temperature distribution. The temperature sensor263is installed along the inner wall of the reaction tube203.

As illustrated inFIG. 4, the controller121, which is a control part (control means), may be configured as a computer including a central processing unit (CPU)121a,a random access memory (RAM)121b,a memory device121c,and an I/O port121d.The RAM121b,the memory device121c,and the I/O port121dare configured to exchange data with the CPU121avia an internal bus121e.An input/output device122including, e.g., a touch panel or the like, is connected to the controller121.

The memory device121cis configured by, for example, a flash memory, a hard disk drive (HDD), or the like. A control program for controlling operations of a substrate processing apparatus, a process recipe for specifying sequences and conditions of film formation as described hereinbelow, or a cleaning recipe for specifying sequences and conditions of initial cleaning as described hereinbelow is readably stored in the memory device121c.The process recipe functions as a program for causing the controller121to execute each sequence in the film formation, as described hereinbelow, to obtain a predetermined result. The cleaning recipe functions as a program for causing the controller121to execute each sequence in the initial cleaning, as described hereinbelow, to obtain a predetermined result. Hereinafter, the process recipe, the cleaning recipe, and the control program may be generally and simply referred to as a “program.” Furthermore, the process recipe or the cleaning recipe may be simply referred to as a “recipe.” When the term “program” is used herein, it may indicate a case of including only the recipe, a case of including only the control program, or a case of including both the recipe and the control program. The RAM121bis configured as a memory area (work area) in which a program, data, and the like read by the CPU121ais temporarily stored.

The I/O port121dis connected to the MFCs241ato241i,the valves243ato243i,the pressure sensor245, the APC valve244, the vacuum pump246, the temperature sensor263, the heater207, the rotation mechanism267, the boat elevator115, the shutter-opening/closing mechanism115s,and the like, as described above.

The CPU121ais configured to read and execute the control program from the memory device121c.The CPU121ais also configured to read the recipe from the memory device121caccording to an input and so on of an operation command from the input/output device122. In addition, the CPU121ais configured to control, according to the contents of the read recipe, the flow rate adjustment operation of various kinds of gases by the MFCs241ato241i,the opening/closing operation of the valves243ato243i,the opening/closing operation of the APC valve244, the pressure regulation operation performed by the APC valve244based on the pressure sensor245, the driving or stopping of the vacuum pump246, the temperature adjustment operation performed by the heater207based on the temperature sensor263, the operation of rotating the boat217with the rotation mechanism267and adjusting the rotation speed of the boat217, the operation of moving the boat217up or down by the boat elevator115, the operation of opening or closing the shutter219sby the shutter-opening/closing mechanism115s,and the like.

The controller121may be configured by installing, on the computer, the aforementioned program stored in an external memory device123. The external memory device123may include, for example, a magnetic disc such as an HDD, an optical disc such as a CD, a magneto-optical disc such as an MO, a semiconductor memory such as a USB memory, and the like. The memory device121cor the external memory device123is configured as a non-transitory computer-readable recording medium. Hereinafter, the memory device121cand/or the external memory device123may be generally and simply referred to as a “recording medium.” When the term “recording medium” is used herein, it may indicate a case of including only the memory device121c,a case of including only the external memory device123, or a case of including both the memory device121cand the external memory device123. Furthermore, the program may be provided to the computer using a communication means such as the Internet or a dedicated line, instead of using the external memory device123.

As a process of manufacturing a semiconductor device using the aforementioned substrate processing apparatus, one or more examples of a series of processing sequences including a film-forming sequence of forming a film on a wafer200as a substrate will be mainly described with reference toFIGS. 5 and 6. In the following descriptions, the operations of the respective parts constituting the substrate processing apparatus are controlled by the controller121.

In the film formation according to a series of processing sequences illustrated inFIG. 5, a film is formed on a wafer200by performing a cycle a predetermined number of times, the cycle including: (a) supplying a precursor gas to the wafer200in a process container of a substrate processing apparatus via a gas supply pipe232aas a first pipe made of metal; (b) supplying an O-containing gas to the wafer200in the process container via a gas supply pipe232bas a second pipe made of metal, wherein a F-containing layer is continuously formed on an inner surface of the second pipe; and (c) supplying a N-and-H-containing gas to the wafer200in the process container via the gas supply pipe232b.

Specifically, in the film formation according to the present embodiments, as illustrated in the gas supply sequence inFIG. 6, a film containing Si, O, C, and N, i.e., a silicon oxycarbonitride film (SiOCN film), is formed as the film on the wafer200by performing a cycle a predetermined number of times (n times, where n is an integer of 1 or larger), the cycle non-simultaneously performing: Step 1 of supplying HCDS gas as the precursor gas to the wafer200in the process container via the gas supply pipe232aand the nozzle249a;Step 2 of supplying C3H6gas as a C-containing gas to the wafer200in the process container via the gas supply pipe232aand the nozzle249a;Step 3 of supplying O2gas as the O-containing gas to the wafer200in the process container via the gas supply pipe232band the nozzle249b;and Step 4 of supplying NH3gas as the N-and-H-containing gas to the wafer200in the process container via the gas supply pipe232band the nozzle249b.

In the present disclosure, for the sake of convenience, the gas supply sequence illustrated inFIG. 6, i.e., the film-forming sequence, may be denoted as follows. The same denotation may be used in other embodiments as described hereinbelow.
(HCDS→C3H6→O2→NH3)×n⇒SiOCN

When the term “wafer” is used in the present disclosure, it may refer to a wafer itself or a laminated body of a wafer and a predetermined layer or film formed on the surface of the wafer. In addition, when the phrase “a surface of a wafer” is used in the present disclosure, it may refer to a surface of a wafer itself or a surface of a predetermined layer or the like formed on a wafer. Furthermore, in the present disclosure, the expression “a predetermined layer is formed on a wafer” may mean that a predetermined layer is directly formed on a surface of a wafer itself or that a predetermined layer is formed on a layer or the like formed on a wafer. In addition, when the term “substrate” is used in the present disclosure, it may be synonymous with the term “wafer.”

Hereinafter, a series of processing sequences illustrated inFIG. 5will be described in detail.

Setting

First, members such as pipes or the like are set in the substrate processing apparatus. Hereinafter, an operation of installing the pipes including the gas supply pipes232aand232bin the substrate processing apparatus will be described.

Pipe Installation

First, the gas supply pipe232ain which a F-containing layer is not formed on its inner surface and the gas supply pipe232bin which a F-containing layer is continuously formed on its inner surface are prepared and installed in the substrate processing apparatus. That is, before a film is formed on the wafer200(before the film formation), the gas supply pipe232ain which a F-containing layer is not formed on its inner surface, the gas supply pipe232b-1in which a F-containing layer is continuously formed on its inner surface, and the gas supply pipe232b-2in which a F-containing layer is continuously formed on its inner surface are prepared, and then incorporated, attached, and installed in the substrate processing apparatus. The formation of the F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2is performed as follows.

F-Containing Layer Formation

Before the gas supply pipe232b(gas supply pipes232b-1and232b-2) is installed in the substrate processing apparatus, a F-containing layer is formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2. That is, before the gas supply pipes232b-1and232b-2are installed in the substrate processing apparatus, the inner surfaces of the gas supply pipes232b-1and232b-2are respectively surface-treated by allowing F2gas, which is a F-containing gas, to flow through the gas supply pipes232b-1and232b-2. In other words, the F2gas chemically reacts with the respective inner surfaces of the gas supply pipes232b-1and232b-2, to form a continuous F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2.

Specifically, the F-containing layer is formed on respective inner surfaces separately by supplying the F2gas to the respective inner surfaces of the gas supply pipes232b-1and232b-2under different processing conditions suitable for each material, with the gas supply pipes232b-1and232b-2separated. The processing conditions for forming the F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2are as illustrated below. The respective processing conditions illustrated below are conditions under which the F2gas chemically reacts with the inner surface of the gas supply pipe232b-1and the inner surface of the gas supply pipe232b-2, to form a continuous F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2.

The processing condition for forming the F-containing layer on the inner surface of the gas supply pipe232b-1(the pipe made of SUS) may be exemplified as follows:

Supply time of F2gas: 75 to 400 minutes.

Furthermore, the processing condition for forming the F-containing layer on the inner surface of the gas supply pipe232b-2(the pipe made of Hastelloy) may be exemplified as follows:

Supply time of F2gas: 75 to 200 minutes.

Furthermore, in the present disclosure, the expression of the numerical range such as “75 to 200 degrees C.” may mean that a lower limit value and an upper limit value are included in that range. Therefore, for example, “75 to 200 degrees C.” may mean “75 degrees C. or higher and 200 degrees C. or lower.” The same applies to other numerical ranges.

By supplying the F2gas into each of the gas supply pipe232b-1and the gas supply pipe232b-2under the aforementioned respective processing conditions, the F2gas and the respective inner surfaces of the gas supply pipe232b-1and the gas supply pipe232b-2chemically react with each other, thereby making it possible to form the continuous F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2. The F-containing layer includes a metal fluoride layer formed by fluorinating metal which is materials of the gas supply pipes232b-1and232b-2. The metal fluoride layer contains iron fluoride (FeF), nickel fluoride (NiF), chromium fluoride (CrF), or the like. The F-containing layer is formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2such that the materials of the gas supply pipes232b-1and232b-2are prevented from being exposed inside the respective gas supply pipes232b-1and232b-2. That is, the respective inner surfaces of the gas supply pipes232b-1and232b-2can be covered with the F-containing layer thereby prevent the materials of the gas supply pipes232b-1and232b-2from being exposed inside the gas supply pipes232b-1and232b-2.

In the film formation as described hereinbelow, an O-containing gas such as O2gas and a N-and-H-containing gas such as NH3gas may react with each other in the gas supply pipe232b, which is a common pipe for the O2gas and the NH3gas, i.e., in the gas supply pipes232b-1and232b-2, to generate water (H2O). Furthermore, the generated water may react with the NH3gas to generate a substance such as ammonia water (NH4OH) in the gas supply pipe232b-1and the gas supply pipe232b-2. The substance such as ammonia water becomes a factor for corroding the material of the gas supply pipe232b-1or232b-2to cause damage to the gas supply pipe232b-1or232b-2. In the present embodiments, the corrosion of the inner surfaces of the gas supply pipe232b-1and the gas supply pipe232b-2and the damage due to the corrosion can be suppressed by using the gas supply pipe232b-1and the gas supply pipe232b-2in which a continuous F-containing layer is formed on the respective inner surfaces when the film formation is performed. Furthermore, since the O2gas and the NH3gas are not mixed and do not react with each other in the gas supply pipe232awhich is not a common pipe for the O2gas and the NH3gas, it is possible to reduce the cost by using the pipe in which a F-containing layer is not formed on its inner surface as the gas supply pipe232a.

The thickness of the F-containing layer formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2may be set to such a thickness that the substance such as ammonia water generated by the reaction between the O2gas and the NH3gas does not chemically react with the inner surfaces of the gas supply pipes232b-1and232b-2in the gas supply pipes232b-1and232b-2when the film formation is performed. Specifically, the thickness of the F-containing layer formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2may be set to such a thickness that the substance such as NH4OH, which is a reactant generated by the reaction between NH3and H2O generated by the reaction between O2and NH3, does not chemically react with the inner surfaces of the gas supply pipes232b-1and232b-2in the gas supply pipes232b-1and232b-2. More specifically, the thickness of the F-containing layer formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2may be set to a thickness in a range of, for example, 1 nm to 50 nm, 2 nm to 40 nm in some embodiments, or 2.5 nm to 35 nm in some embodiments.

Furthermore, the thickness of the F-containing layer formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2may become thicker as the processing temperature is raised, depending on the respective processing temperatures (pipe temperatures) when forming the F-containing layer. However, the F-containing layer may be formed under an optimized processing condition depending on the material of the gas supply pipe232b,since the inner surfaces of the gas supply pipes232b-1and232b-2may be corroded if the processing temperature is too high when forming the F-containing layer. Specifically, the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-1may be set lower than the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-2. Furthermore, the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-1may be set equal to or higher than the temperature of the gas supply pipe232b-1in the film formation as described hereinbelow. In addition, the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-2may be set higher than the temperature of the gas supply pipe232b-2in the film formation as described hereinbelow.

Furthermore, as described above, the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-1may be set lower than the processing temperature when forming the F-containing layer on the inner surface of the gas supply pipe232b-2, and the supply time of the F2gas when forming the F-containing layer on the inner surface of the gas supply pipe232b-1may be set longer than the supply time of the F2gas when forming the F-containing layer on the inner surface of the gas supply pipe232b-2. By controlling the balance between the processing temperature and the supply time of the F2gas when forming the F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2, the F-containing layer having an appropriate thickness can be formed on the respective inner surfaces of the gas supply pipes232b-1and232b-2while suppressing the corrosion of the respective inner surfaces of the gas supply pipes232b-1and232b-2.

Initial Cleaning

After the setting is completed and before a film is formed on the wafer200(before the film formation), the initial cleaning is performed on the interior of the process chamber201and the interiors of the nozzles249aand249bby performing the chamber cleaning, the first nozzle cleaning, and the second nozzle cleaning. Hereinafter, a series of operations of the initial cleaning will be described.

Empty Boat Loading

The shutter219sis moved by the shutter-opening/closing mechanism115sto open the lower end opening of the manifold209(shutter opening). Thereafter, the empty boat217, i.e., the boat217not charged with the wafers200, is lifted up by the boat elevator115to be loaded into the process chamber201. In this state, the seal cap219seals the lower end of the manifold209through the O-ring220b.

Pressure Regulation and Temperature Adjustment

After the loading of the empty boat217into the process chamber201is completed, the interior of the process chamber201is vacuum-exhausted by the vacuum pump246to reach a desired pressure (chamber cleaning pressure). Furthermore, the interior of the process chamber201is heated by the heater207to a desired temperature (chamber cleaning temperature). In this operation, the members in the process chamber201, i.e., the inner wall of the reaction tube203, the surfaces of the nozzles249aand249b,the surface of the boat217, and the like, are also heated to the chamber cleaning temperature. In addition, the rotation of the boat217by the rotation mechanism267is started. The operation of the vacuum pump246, the heating of the interior of the process chamber201, and the rotation of the boat217may be continuously performed at least until the nozzle cleaning as described hereinbelow is completed. The boat217may not be rotated.

Chamber Cleaning

After the internal pressure and temperature of the process chamber201are stabilized, the interior of the process chamber201is cleaned by supplying ClF3gas and NO gas into the process chamber201. Specifically, the valves243eand243gare opened to allow ClF3gas to flow through the gas supply pipe232eand to allow NO gas to flow through the gas supply pipe232g.The flow rates of the ClF3gas and the NO gas are adjusted by the MFCs241eand241g, respectively. The ClF3gas and the NO gas are supplied into the process chamber201via the gas supply pipes232aand232band the nozzles249aand249b,respectively, and are exhausted through the exhaust port231a.Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

NO gas supply flow rate: 0.5 to 10 slm

N2gas supply flow rate (for each gas supply pipe): 0 to 10 slm

Supply time of each gas: 1 to 60 minutes or 10 to 20 minutes in some embodiments

Processing temperature (chamber cleaning temperature): 100 to 350 degrees C. or 200 to 300 degrees C. in some embodiments

Processing pressure (chamber cleaning pressure): 1,333 to 53,329 Pa or 9,000 to 16,665 Pa in some embodiments.

By supplying the ClF3gas and the NO gas into the process chamber201under the aforementioned processing condition, NO gas can be added to the ClF3gas, and these gases can be mixed and reacted in the process chamber201. By this reaction, active species such as, e.g., fluorine radicals (F*) and nitrosyl fluoride (FNO) (hereinafter, these may be generally referred to as FNO or the like), can be generated in the process chamber201. As a result, a mixed gas obtained by adding FNO or the like to the ClF3gas exists in the process chamber201. The mixed gas obtained by adding FNO or the like to the ClF3gas contacts the members in the process chamber201, for example, the inner wall of the reaction tube203, the surfaces of the nozzles249aand249b,the surface of the boat217, and the like. In this operation, deposits adhered to the surfaces of the members in the process chamber201can be removed by a thermochemical reaction (etching reaction). FNO or the like acts to promote the etching reaction by the ClF3gas and to increase the etching rate of the deposits, i.e., acts to assist the etching.

After a predetermined time has passed and the cleaning of the interior of the process chamber201is completed, the valves243eand243gare closed to stop the supply of the ClF3gas and the NO gas into the process chamber201. Then, the interior of the process chamber201is vacuum-exhausted and the gas or the like remaining in the process chamber201is removed from the interior of the process chamber201(purge). In this operation, the valves243hand243iare opened to supply N2gas into the process chamber201. The N2gas acts as a purge gas.

As the cleaning gas, it may be possible to use, e.g., hydrogen fluoride (HF) gas, nitrogen fluoride (NF3) gas, F2gas, or a mixed gas thereof, as well as the ClF3gas. This applies to the nozzle cleaning as described hereinbelow.

As the additive gas, it may be possible to use, e.g., hydrogen (H2) gas, O2gas, nitrous oxide (N2O) gas, isopropyl alcohol ((CH3)2CHOH, abbreviation: IPA) gas, methanol (CH3OH) gas, water vapor (H2O gas), HF gas, or a mixed gas thereof, as well as the NO gas.

Furthermore, when the HF gas is used as the additive gas, one of the F2gas, the ClF3gas, the NF3gas, and a mixed gas thereof may be used as the cleaning gas. In addition, when the HF gas is used as the cleaning gas, and one of the IPA gas, the methanol gas, the H2O gas, and a mixed gas thereof is used as the additive gas, the aforementioned processing temperature may be set to a predetermined temperature in a range of, for example, 30 to 300 degrees C. or 50 to 200 degrees C. in some embodiments.

As the inert gas, it may be possible to use, a rare gas such as Ar gas, He gas, Ne gas, Xe gas, or the like, as well as the N2gas. The same applies to respective steps as described hereinbelow.

Pressure Regulation and Temperature Adjustment

After the chamber cleaning is completed, the interior of the process chamber201is vacuum-exhausted by the vacuum pump246to reach a desired pressure (nozzle cleaning pressure). Furthermore, the interiors of the nozzles249aand249bare heated by the heater207to a desired temperature (nozzle cleaning temperature).

First Nozzle Cleaning

After the internal pressure of the process chamber201and the internal temperature of the nozzles249aand249bare stabilized, the interior of the nozzle249ais cleaned by supplying ClF3gas into the nozzle249a.Specifically, the valve243eis opened to allow ClF3gas to flow through the gas supply pipe232e.The flow rate of the ClF3gas is adjusted by the MFC241e. The ClF3gas is supplied into the nozzle249avia the gas supply pipe232aand flown into the process chamber201and is exhausted through the exhaust port231a.Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

N2gas supply flow rate (for each gas supply pipe): 0 to 10 slm

Supply time of each gas: 1 to 60 minutes or 10 to 20 minutes in some embodiments

Processing temperature (nozzle cleaning temperature): 400 to 500 degrees C. or 400 to 450 degrees C. in some embodiments

Processing pressure (nozzle cleaning pressure): 1,333 to 40,000 Pa or 6,666 to 16,665 Pa in some embodiments.

By supplying the ClF3gas into the nozzle249aunder the aforementioned processing condition, deposits adhered to the interior of the nozzle249acan be removed by a thermochemical reaction. After a predetermined time has passed and the cleaning of the interior of the nozzle249ais completed, the valve243eis closed to stop the supply of the ClF3gas into the nozzle249a.Then, the interior of the process chamber201is purged in a processing procedure similar to that of the purge in the chamber cleaning described above (purge).

Second Nozzle Cleaning

After the cleaning of the interior of the nozzle249ais completed, the interior of the nozzle249bis cleaned by supplying ClF3gas into the gas supply pipe232b.Specifically, the valve243fis opened to allow ClF3gas to flow through the gas supply pipe232f.The flow rate of the ClF3gas is adjusted by the MFC241f.The ClF3gas is supplied into the nozzle249bvia the gas supply pipe232band flown into the process chamber201and is exhausted through the exhaust port231a.Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be similar to the processing condition in the first nozzle cleaning described above.

By supplying the ClF3gas into the nozzle249bunder the aforementioned processing condition, deposits adhered to the interior of the nozzle249bcan be removed by a thermochemical reaction. After a predetermined time has passed and the cleaning of the interior of the nozzle249bis completed, the valve243fis closed to stop the supply of the ClF3gas into the nozzle249b.Then, the interior of the process chamber201is purged in a processing procedure similar to that of the purge in the chamber cleaning described above (purge).

After the cleaning of the interior of the nozzle249bis completed, the internal atmosphere of the process chamber201is substituted with an inert gas (inert gas substitution). The internal pressure of the process chamber201is returned to an atmospheric pressure (returning to atmospheric pressure).

Empty Boat Unloading

The seal cap219is moved down by the boat elevator115to open the lower end of the manifold209. Then, the empty boat217is unloaded from the lower end of the manifold209to the outside of the reaction tube203(boat unloading). After the boat unloading, the shutter219sis moved so that the lower end opening of the manifold209is sealed by the shutter219sthrough the O-ring220c(shutter closing).

Furthermore, prior to performing the boat unloading, the processing of the wafers200, namely the same process as the film-forming process, may be performed in the process container according to processing procedures and processing conditions similar to those in the film formation as described hereinbelow (pre-coating). By performing the pre-coating, a pre-coating film (SiCON film) containing Si, O, C, and N can be formed on the respective surfaces of the members in the process container. The pre-coating may be performed, for example, in a state where the cleaned empty boat217is accommodated in the process container.

The initial cleaning is completed by the series of operations described above. By the initial cleaning, the environment and state in the process container before the film-forming process can be adjusted.

After the initial cleaning is completed, the film-forming process of forming a film on the wafer200is performed. Hereinafter, a series of operations of the film-forming process will be described.

Wafer Charging and Boat Loading

After the boat unloading is completed, when a plurality of wafers200is charged on the boat217(wafer charging), the shutter219sis moved by the shutter-opening/closing mechanism115sto open the lower end opening of the manifold209(shutter opening). Thereafter, as illustrated inFIG. 1, the boat217supporting the plurality of wafers200is lifted up by the boat elevator115and is loaded into the process chamber201(boat loading). In this state, the seal cap219seals the lower end of the manifold209through the O-ring220b.

Pressure Regulation and Temperature Adjustment

The interior of the process chamber201, namely the space in which the wafers200are located, is vacuum-exhausted (depressurization-exhausted) by the vacuum pump246to reach a desired pressure (film-forming pressure). Furthermore, the wafers200in the process chamber201are heated by the heater207to a desired temperature (film-forming temperature). In addition, the rotation of the wafers200by the rotation mechanism267is initiated. The exhaust of the interior of the process chamber201and the heating and rotating the wafers200may be all continuously performed at least until the processing of the wafers200is completed.

Film Formation

Thereafter, the following steps 1 to 4 are sequentially performed.

In this step, HCDS gas is supplied to the wafer200in the process container (HCDS gas supplying). Specifically, the valve243ais opened to allow the HCDS gas to flow through the gas supply pipe232a.The flow rate of the HCDS gas is adjusted by the MFC241a.The HCDS gas is supplied into the process chamber201via the nozzle249aand is exhausted through the exhaust port231a.In this operation, the HCDS gas is supplied to the wafer200. Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

HCDS gas supply flow rate: 0.01 to 2 slm or 0.1 to 1 slm in some embodiments

N2gas supply flow rate (for each gas supply pipe): 0 to 10 slm

Supply time of each gas: 1 to 120 seconds or 1 to 60 seconds in some embodiments

Processing temperature: 250 to 800 degrees C. or 400 to 700 degrees C. in some embodiments

Processing pressure: 1 to 2,666 Pa or 67 to 1,333 Pa in some embodiments.

By supplying the HCDS gas to the wafer200under the aforementioned condition, a Si-containing layer containing Cl is formed as a first layer on the outermost surface of the wafer200. The Si-containing layer containing Cl is formed by physical adsorption of HCDS on the outermost surface of the wafer200, chemical adsorption of a substance (hereinafter, SixCly) obtained by decomposing HCDS or a part of HCDS thereon, deposition of Si by thermal decomposition of HCDS thereon, or the like. The Si-containing layer containing Cl may be an adsorption layer (a physical adsorption layer or a chemical adsorption layer) of HCDS or SixCly, or may be a deposited layer of Si containing Cl. In the present disclosure, the Si-containing layer containing Cl may be simply referred to as a Si-containing layer.

After the first layer is formed, the valve243ais closed to stop the supply of the HCDS gas into the process chamber201. Then, the interior of the process chamber201is vacuum-exhausted and the gas or the like remaining in the process chamber201is removed from the interior of the process chamber201(purge). In this operation, the valves243hand243iare opened to supply N2gas into the process chamber201. The N2gas acts as a purge gas.

After Step 1 is completed, C3H6gas is supplied to the wafer200in the process container, namely the first layer formed on the wafer200(C3H6gas supply). Specifically, the valve243cis opened to allow C3H6gas to flow through the gas supply pipe232c.The flow rate of the C3H6gas is adjusted by the MFC241c.The C3H6gas is supplied into the process chamber201via the gas supply pipe232aand the nozzle249aand is exhausted through the exhaust port231a. In this operation, the C3H6gas is supplied to the wafer200. Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

Supply time of C3H6gas: 1 to 120 seconds or 1 to 60 seconds in some embodiments

Processing pressure: 1 to 6,000 Pa or 1 to 5,000 Pa in some embodiments.

Other processing conditions may be similar to the processing conditions of Step 1.

By supplying the C3H6gas to the wafer200under the aforementioned condition, a C-containing layer is formed on the first layer, whereby a second layer containing Si and C is formed on the wafer200.

After the second layer is formed, the valve243cis closed to stop the supply of the C3H6gas into the process chamber201. Then, the gas or the like, which remains in the process chamber201, is removed from the interior of the process chamber201according to processing procedures similar to those of the purge in Step 1 (purge).

As the reaction gas (C-containing gas), it may be possible to use, hydrocarbon-based gas such as acetylene (C2H2) gas, ethylene (C2H4) gas, or the like, as well as the C3H6gas.

After Step 2 is completed, O2gas is supplied to the wafer200in the process container, namely the second layer formed on the wafer200(O2gas supply). Specifically, the valve243bis opened to allow the O2gas to flow through the gas supply pipe232b.The flow rate of the O2gas is adjusted by the MFC241b.The O2gas is supplied into the process chamber201via the nozzle249band is exhausted through the exhaust port231a.In this operation, the O2gas is supplied to the wafer200. Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

Supply time of O2gas: 1 to 120 seconds or 1 to 60 seconds in some embodiments

Processing pressure: 1 to 4,000 Pa or 1 to 3,000 Pa in some embodiments.

Other processing conditions may be similar to the processing conditions of Step 1.

By supplying the O2gas to the wafer200under the aforementioned condition, at least a portion of the second layer formed on the wafer200is oxidized (modified). By modifying the second layer, a third layer containing Si, O, and C, i.e., a silicon oxycarbide layer (SiOC layer), is formed on the wafer200. When the third layer is formed, an impurity such as Cl contained in the second layer constitutes a gaseous substance containing at least Cl in the process of the modifying reaction of the second layer by the O2gas, and is exhausted from the interior of the process chamber201. Thus, the third layer becomes a layer having fewer impurities such as Cl or the like than the first and second layers.

After the third layer is formed, the valve243bis closed to stop the supply of the O2gas into the process chamber201. Then, the gas or the like, which remains in the process chamber201, is removed from the interior of the process chamber201according to processing procedures similar to those of the purge in Step 1 (purge).

As the reaction gas (O-containing gas), it may be possible to use, for example, ozone (O3) gas, water vapor (H2O gas), nitrogen monoxide (NO) gas, nitrous oxide (N2O) gas, or the like, as well as the O2gas.

After Step 3 is completed, NH3gas is supplied to the wafer200in the process container, namely the third layer formed on the wafer200(NH3gas supply). Specifically, the valve243dis opened to allow NH3gas to flow through the gas supply pipe232d.The flow rate of the NH3gas is adjusted by the MFC241d.The NH3gas is supplied into the process chamber201via the gas supply pipe232band the nozzle249band is exhausted through the exhaust port231a. In this operation, the NH3gas is supplied to the wafer200. Simultaneously, the valves243hand243imay be opened to supply N2gas into the process chamber201via the nozzles249aand249b.

The processing condition in this step may be exemplified as follows:

Supply time of NH3gas: 1 to 120 seconds or 1 to 60 seconds in some embodiments

Processing pressure: 1 to 4,000 Pa or 1 to 3,000 Pa in some embodiments.

Other processing conditions may be similar to the processing conditions of Step 1.

By supplying the NH3gas to the wafer200under the aforementioned condition, at least a portion of the third layer formed on the wafer200is nitrided (modified). By modifying the third layer, a fourth layer containing Si, O, C, and N, i.e., a silicon oxycarbonitride layer (SiOCN layer), is formed on the wafer200. When the fourth layer is formed, an impurity such as Cl contained in the third layer constitutes a gaseous substance containing at least Cl in the process of the modifying reaction of the third layer by the NH3gas, and is exhausted from the interior of the process chamber201. Thus, the fourth layer becomes a layer having fewer impurities such as Cl or the like than the third layer.

After the fourth layer is formed, the valve243dis closed to stop the supply of the NH3gas into the process chamber201. Then, the gas or the like, which remains in the process chamber201, is removed from the interior of the process chamber201according to processing procedures similar to those of the purge in Step 1 (purge).

As the reaction gas (N-and-H-containing gas), it may be possible to use, for example, hydrogen nitride-based gas such as diazene (N2H2) gas, hydrazine (N2H4) gas, N3H8gas, or the like, as well as the NH3gas.

Performing a Predetermined Number of Times

A cycle which non-simultaneously, i.e., non-synchronously, performs steps 1 to 4 described above is performed a predetermined number of times (n times, where n is an integer of 1 or larger). Thus, a SiOCN film having a predetermined composition and a predetermined thickness can be formed on the wafer200. The aforementioned cycle may be repeated multiple times. That is, the thickness of the fourth layer formed per one cycle may be set to be smaller than a desired thickness and the aforementioned cycle may be repeated multiple times until the thickness of the SiOCN film formed by laminating the fourth layer becomes equal to the desired film thickness.

After-Purging and Returning to Atmospheric Pressure

After the film formation is completed, the N2gas as a purge gas is supplied from each of the nozzles249aand249binto the process chamber201and is exhausted through the exhaust port231a.Thus, the interior of the process chamber201is purged and the gas or the reaction byproduct, which remains in the process chamber201, is removed from the interior of the process chamber201(after-purging). Thereafter, the internal atmosphere of the process chamber201is substituted by an inert gas (inert gas substitution). The internal pressure of the process chamber201is returned to an atmospheric pressure (returning to atmospheric pressure).

Boat Unloading and Wafer Discharging

The seal cap219is moved down by the boat elevator115to open the lower end of the manifold209. Then, the processed wafers200supported on the boat217are unloaded from the lower end of the manifold209to the outside of the reaction tube203(boat unloading). After the boat unloading, the shutter219sis moved so that the lower end opening of the manifold209is sealed by the shutter219sthrough the O-ring220c(shutter closing). The processed wafers200are unloaded to the outside of the reaction tube203and are subsequently discharged from the boat217(wafer discharging).

(3) Effects according to the Present Embodiment

According to the present embodiments, one or more effects as set forth below may be achieved.

(a) By supplying the O2gas and the NH3gas using the pipe in which the F-containing layer is formed on its inner surface, it is possible to improve the quality of the SiOCN film formed on the wafer200, i.e., the quality of the film-forming process.

As described above, this is because, when the aforementioned film formation is performed, the O2gas remaining in the gas supply pipe232bat the start of Step 4 may react with the NH3gas supplied into the gas supply pipe232bby performing Step 4 to generate water (H2O) in the gas supply pipe232b.Furthermore, ammonia water (NH4OH) or the like may be generated in the gas supply pipe232bby the reaction between the water and the NH3gas. If the F-containing layer is not formed on the inner surface of the gas supply pipe232b,the ammonia water generated in the gas supply pipe232bbecomes a factor for corroding the inner surface to generate foreign substances containing Fe or Ni (metal particles, hereinafter, also simply referred to as particles) in the gas supply pipe232b.The state of this reaction is shown inFIG. 7A. The particles generated in the gas supply pipe232bmay diffuse into the process chamber201and adsorb on the surface of the wafer200, thereby deteriorating the quality of the SiOCN film formed on the wafer200.

On the other hand, in the present embodiments, the NH3gas and the O2gas are supplied by using the gas supply pipe232b(gas supply pipes232b-1and232b-2) in which the F-containing layer, specifically, the metal fluoride layer, is formed on its inner surface. The F-containing layer formed on the inner surface of the gas supply pipe232bfunctions as a so-called passivation layer or a passivating layer (passive layer). By the action of the F-containing layer, even when the ammonia water is generated in the gas supply pipe232b,it is possible to suppress the corrosion of the inner surface of the gas supply pipe232b.The state of this reaction is shown inFIG. 7B. Thus, it is possible to suppress the generation of particles in the gas supply pipe232b,and as a result, to improve the quality of the SiOCN film formed on the wafer200. Furthermore, since the O2gas and the NH3gas are not mixed and do not react with each other in the gas supply pipe232a,which is not a common pipe for the O2gas and the NH3gas, the corrosion of the inner surface of the gas supply pipe232adue to the reaction between the O2gas and the NH3gas does not occur. Thus, it is possible to reduce the cost by using the pipe in which the F-containing layer is not formed on its inner surface as the gas supply pipe232a.

(b) By allowing the F-containing layer formed on the respective gas supply pipes232b-1and232b-2to become a continuous layer and by preventing the materials of the respective gas supply pipes232b-1and232b-2from being exposed inside the gas supply pipes232b-1and232b-2, it is possible to reliably suppress the corrosion of the respective inner surfaces of the gas supply pipes232b-1and232b-2. As a result, it is possible to reliably improve the quality of the film-forming process.

(c) By setting the thickness of the F-containing layer formed on the respective gas supply pipes232b-1and232b-2to such a thickness that the ammonia water which is a reactant generated in the respective gas supply pipes232b-1and232b-2and the respective inner surfaces of the gas supply pipes232b-1and232b-2do not chemically react with each other, it is possible to more reliably suppress the corrosion of the inner surfaces of the gas supply pipes232b-1and232b-2. As a result, it is possible to more reliably improve the quality of the film-forming process.

Furthermore, if the thickness of the F-containing layer is less than 1 nm, the inner surfaces of the gas supply pipes232b-1and232b-2may chemically react with the ammonia water to be corroded. By setting the thickness of the F-containing layer to 1 nm or greater, it is possible to avoid the corrosion due to the chemical reaction between the ammonia water and the inner surfaces of the gas supply pipes232b-1and232b-2. By setting the thickness of the F-containing layer to 2 nm or greater, it is possible to reliably achieve the aforementioned effects. By setting the thickness of the F-containing layer to 2.5 nm or greater, it is possible to more reliably achieve the aforementioned effects. In addition, if the thickness of the F-containing layer exceeds 50 nm, the corrosion of the inner surfaces of the gas supply pipes232b-1and232b-2by the F2gas proceeds, which may result in cracks or delamination in the F-containing layer. By setting the thickness of the F-containing layer to 50 nm or smaller, it is possible to suppress the occurrence of cracks or delamination in the F-containing layer due to the corrosion of the inner surfaces of the gas supply pipes232b-1and232b-2by the F2gas. By setting the thickness of the F-containing layer to 40 nm or smaller, it is possible to reliably achieve the aforementioned effects. By setting the thickness of the F-containing layer to 35 nm or smaller, it is possible to more reliably achieve the aforementioned effects.

(d) By forming the F-containing layer on the respective inner surfaces of the gas supply pipes232b-1and232b-2before installing the gas supply pipes232b-1and232b-2in the substrate processing apparatus, the F-containing layer having an optimum thickness can be formed on the respective inner surfaces of the pipes separately under different conditions (under respective optimum conditions) in a state in which the respective pipes are separated, when the gas supply pipe232bincludes the gas supply pipe232b-1as the pipe made of SUS and the gas supply pipe232b-2as the pipe made of Hastelloy, which are different in material, as in the present embodiments. That is, the pipes made of different materials in which the F-containing layer is formed on the respective inner surfaces under respective optimum conditions can be used at a position near the process container and a position far from the process container.

As described above, this is because, after the pipe made of SUS and the pipe made of Hastelloy in which the F-containing layer is not formed on the respective inner surfaces are installed in the substrate processing apparatus including the F2gas supply system configured to supply the F2gas into the process container, when the F-containing layer is formed on the respective inner surfaces of the pipes in-situ (when the formation of the F-containing layer on the respective inner surfaces of the pipes and the film-forming process are performed in the same apparatus), since the respective inner spaces of the pipes are adjacent to and in fluid communication with each other, the processing conditions such as the supply time of the F2gas or the like cannot be changed according to the materials of the pipes. That is, the F-containing layer cannot be formed separately on the respective inner surfaces of the pipe made of SUS and the pipe made of Hastelloy under respective optimum conditions. In such a case, the F-containing layer on the respective inner surfaces of the pipe made of SUS and the pipe made of Hastelloy may be formed under the same conditions simultaneously.

On the other hand, in the present embodiments, in a state in which the respective pipes are separated before installing the pipe made of SUS and the pipe made of Hastelloy in the substrate processing apparatus, the F-containing layer having an optimum thickness can be formed on the respective inner surfaces under the optimum conditions of the respective pipes. That is, in the present embodiments, since the process of forming the F-containing layer is performed ex-situ (since the formation of the F-containing layer on the inner surfaces of the pipe and the film-forming process are performed in different apparatuses), the F-containing layer can be formed on the respective inner surfaces of the pipes made of different materials under respective optimum conditions in a state in which the respective pipes are separated. In addition, in the present embodiments, since the process of forming the F-containing layer is performed ex-situ, the present embodiments can be applied to a substrate processing apparatus not including the F2gas supply system. Of course, the present embodiments may also be applied to a substrate processing apparatus including the F2gas supply system.

(e) By performing the chamber cleaning before performing the film formation, it is possible to enhance the cleanliness in the process container and to further improve the quality of the film-forming process performed in the process chamber201.

(f) By performing the first and second nozzle cleanings before performing the film formation, it is possible to enhance the cleanliness in the nozzles and to further improve the quality of the film-forming process performed in the process chamber201.

(g) By performing the chamber cleaning and the first and second nozzle cleanings before performing the film formation, it is possible to enhance the cleanliness in the process container and the nozzles, and as a result, to further improve the quality of the film-forming process performed in the process chamber201. Furthermore, by sequentially performing the chamber cleaning and the first and second nozzle cleanings before performing the film formation as in the present embodiments, it is possible to shorten the total temperature increasing/decreasing time in the process container and to avoid a decrease in productivity of substrate processing.

(h) By performing the pre-coating before performing the film formation, it is possible to adjust the environment and conditions in the process chamber201before the film formation. Furthermore, it is possible to suppress the generation of particles in the process chamber201. As a result, it is possible to further improve the quality of the film-forming process performed in the process chamber201.

(i) The generation of particles due to the corrosion of the inner surface of the gas supply pipe232bby the aforementioned ammonia water is particularly noticeable when the film formation is performed using the new (unused) gas supply pipe232b,for example, when the film formation is performed after operating the substrate processing apparatus or when the film formation is performed after replacing the gas supply pipe232b.On the other hand, when the film formation is performed using the used gas supply pipe232b,particles due to such corrosion are unlikely to occur. This is considered to be because, as using the gas supply pipe232b,the inner surface of the gas supply pipe232bcompletely reacts with the ammonia water and this reaction is saturated. Furthermore, the particles due to such corrosion hardly occur on the inner surface of the manifold209, the surface of the seal cap219, or the surface of the rotary shaft255, and tend to be significantly generated on the inner surface of the gas supply pipe232b.This is considered to be caused by a difference in a degree of mixing or concentration of the O2gas and the NH3gas between the interior of the process container and the interior of the gas supply pipe232b.From these viewpoints, it can be said that the present embodiments is particularly significant when the film formation is performed using the new gas supply pipe232b.

(j) According to the present embodiments, by forming the F-containing layer on the inner surface of the gas supply pipe232b,it is possible not only to suppress the damage due to the corrosion of the inner surface of the gas supply pipe232bby the ammonia water, but also to recovery the damage when the inner surface of the gas supply pipe232bis damaged in an initial state.

(k) The aforementioned effects by the formation of the F-containing layer on the inner surface of the gas supply pipe232bcan be maintained, until the gas supply pipe232bis replaced next time, after the gas supply pipe232bin which the F-containing layer is formed on the inner surface is installed in the substrate processing apparatus.

(l) According to the present embodiments, by supplying the O2gas and the NH3gas via the common pipe, it is possible to reduce the number of pipes and to reduce the cost, compared with the case of supplying the O2gas and the NH3gas via different pipes. Moreover, the maintenance becomes easy.

(m) The effects of the present embodiments can be similarly achieved even when a F-containing gas other than the F2gas is used to form the F-containing layer on the inner surface of the gas supply pipe232b.

(n) The effects of the present embodiments can be similarly achieved even when a precursor gas other than the HCDS gas is used, when a C-containing gas other than the C3H6gas is used, when an O-containing gas other than the O2gas is used, when a N-and-H-containing gas other than the NH3gas is used, when a cleaning gas other than the ClF3gas is used, when an additive gas other than the NO gas is used, or when an inert gas other than the N2gas is used.

Other Embodiments of the Present Disclosure

While some embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the aforementioned embodiments but may be differently modified without departing from the spirit of the present disclosure.

In the aforementioned embodiments, the processing sequence of sequentially performing setting, chamber cleaning, first nozzle cleaning, second nozzle cleaning, pre-coating, and the film formation has been illustrated, but any step of chamber cleaning, first nozzle cleaning, second nozzle cleaning, and pre-coating may not be performed, as illustrated in (1) to (7) below. Even in these cases, the same effects as those of the aforementioned embodiments described with reference toFIGS. 5 and 6may be achieved.

Furthermore, in the film formation, a film may be formed on the wafer200by the gas supply sequences illustrated below. Even in these cases, when an O-containing gas such as O2gas and a N-and-H-containing gas such as NH3gas are supplied from the gas supply pipe232b, ammonia water may be generated in the gas supply pipe232b.Even in these cases, by applying the method of the present disclosure, the same effects as those of the aforementioned embodiments described with reference toFIGS. 5 and 6may be achieved. The C-containing gas such as the C3H6gas is not limited as being supplied from the gas supply pipe232aand the nozzle249a,but may be supplied from the gas supply pipe232band the nozzle249b.Even in this case, the same effects as those of the aforementioned embodiments described with reference toFIGS. 5 and 6may be achieved.
(HCDS→C3H6→NH3→O2)×n⇒SiOCN
(HCDS→O2→NH3)×n⇒SiON
(HCDS→NH3→O2)×n⇒SiON

Furthermore, in the aforementioned embodiments, there have been described some examples in which the gas supply pipe232bfor supplying the O2gas and the NH3gas includes the gas supply pipe232b-1made of SUS and the gas supply pipe232b-2made of Hastelloy. However, the present disclosure is not limited thereto and any of the pipe made of SUS, the pipe made of Hastelloy, a pipe made of Inconel, and other pipes made of metal may be used as the gas supply pipes232b-1and232b-2, and the materials of the respective pipes may be equal or different.

Recipes used in each processing may be prepared individually according to the processing contents and may be stored in the memory device121cvia a telecommunication line or the external memory device123. Moreover, at the start of each processing, the CPU121amay properly select an appropriate recipe from the recipes stored in the memory device121caccording to the processing contents. Thus, it is possible for a single substrate processing apparatus to form films of different kinds, composition ratios, qualities, and thicknesses with enhanced reproducibility. In addition, it is possible to reduce an operator's burden and to quickly start the substrate processing while avoiding an operation error.

The recipes mentioned above are not limited to newly-prepared ones but may be prepared by, for example, modifying the existing recipes already installed in the substrate processing apparatus. When modifying the recipes, the modified recipes may be installed in the substrate processing apparatus via a telecommunication line or a recording medium storing the recipes. In addition, the existing recipes already installed in the substrate processing apparatus may be directly modified by operating the input/output device122of the existing substrate processing apparatus.

In the aforementioned embodiments, there have been described some examples in which films are formed using a batch-type substrate processing apparatus capable of processing a plurality of substrates at a time. The present disclosure is not limited to the aforementioned embodiments but may be appropriately applied to, e.g., a case where films are formed using a single-wafer-type substrate processing apparatus capable of processing a single substrate or several substrates at a time. In addition, in the aforementioned embodiments, there have been described examples in which films are formed using the substrate processing apparatus provided with a hot-wall-type process furnace. The present disclosure is not limited to the aforementioned embodiments but may be appropriately applied to a case where films are formed using a substrate processing apparatus provided with a cold-wall-type process furnace.

In the case of using these substrate processing apparatuses, each processing may be performed by the processing procedures and processing conditions similar to those of the aforementioned embodiments. Effects similar to those of the aforementioned embodiments may be achieved.

The embodiments described above may be appropriately combined with one another. The processing procedures and processing conditions in this operation may be similar to, for example, the processing procedures and processing conditions of the aforementioned embodiments.

A pipe made of SUS and a pipe made of Hastelloy are prepared, and in a state in which the respective pipes are separated, a metal fluoride layer was formed on respective inner surfaces of the pipes separately under a plurality of different conditions (conditions 1 to 3). Then, the pipe made of SUS and the pipe made of Hastelloy in which the metal fluoride layer was formed on the respective inner surfaces under the conditions 1 to 3 were installed respectively as the gas supply pipes232b-1and232b-2illustrated inFIG. 2in the substrate processing apparatus illustrated inFIG. 1. Then, a SiOCN film was formed on a wafer by the film-forming sequence illustrated inFIG. 6using the substrate processing apparatus.

Pipe temperatures (processing temperatures) and supply times of F2gas according to the conditions 1 to 3 for forming the metal fluoride layer on the respective inner surface of the pipe made of SUS and the pipe made of Hastelloy were set as illustrated inFIG. 8. Other processing conditions were set to predetermined conditions which fall within the processing condition ranges described in the aforementioned embodiments.

Then, thicknesses of the metal fluoride layer formed on the respective inner surfaces of the pipe made of SUS and the pipe made of Hastelloy and damages due to corrosion of the respective inner surfaces of the pipe made of SUS and the pipe made of Hastelloy after performing a film-forming process on the wafer a predetermined number of times were observed under the conditions 1 to 3. The results are shown inFIG. 8. The “Thickness of metal fluoride layer” inFIG. 8indicates a result of determination as “O” when the thickness of the metal fluoride layer formed on the respective inner surfaces of the pipes has reached a target thickness, and as “X” when the thickness has not reached the target thickness. Furthermore, in the present Embodiment Example, the target thickness of the metal fluoride layer formed on the inner surface of the pipe made of SUS was set to 30 to 40 nm, and the target thickness of the metal fluoride layer formed on the inner surface of the pipe made of Hastelloy was set to 10 to 20 nm. In addition, “Pipe damage after film formation” inFIG. 8indicates a result of determination as “O” when there is no damage due to the corrosion of the inner surface of the pipe after performing the film-forming process a predetermined number of times, and as “X” when there is damage.

As shown inFIG. 8, when the pipe made of SUS is used as the gas supply pipe for supplying the O2gas and the NH3gas, it was confirmed that, by setting the pipe temperature when forming the metal fluoride layer at 150 to 180 degrees C. and the supply time of the F2gas to 200 to 400 minutes, it is possible to form the metal fluoride layer having the target thickness, e.g., 30 to 40 nm, on the inner surface of the pipe made of SUS and to suppress the damage due to the corrosion of the inner surface of the pipe made of SUS.

Furthermore, when the pipe made of Hastelloy is used as the gas supply pipe for supplying the O2gas and the NH3gas, it was confirmed that, by setting the pipe temperature when forming the metal fluoride layer at 200 to 250 degrees C. and the supply time of the F2gas to 100 to 200 minutes, it is possible to form the metal fluoride layer having the target thickness, e.g., 10 to 20 nm, on the inner surface of the pipe made of Hastelloy and to suppress the damage due to the corrosion of the inner surface of the pipe made of Hastelloy.

That is, the metal fluoride layer having the target thickness could be formed and no pipe damage due to corrosion was observed in the pipe made of Hastelloy, by setting the processing temperature at, for example, 200 to 250 degrees C. and the supply time of the F2gas to, for example, 100 to 200 minutes when forming the metal fluoride layer. However, in the pipe made of SUS, the metal fluoride layer having the target thickness could not be formed and the pipe damage due to corrosion was observed, even if the processing temperature was set to 200 to 250 degrees C. and the supply time of the F2gas was set to 100 to 200 minutes when forming the metal fluoride layer. That is, it was confirmed that the metal fluoride layer may be formed on the inner surface of the pipe under an optimum condition according to the material of the pipe as the common pipe for supplying the O2gas and the NH3gas. Specifically, it was confirmed that, for example, the pipe temperature when forming the metal fluoride layer on the pipe made of SUS may be set lower than the pipe temperature when forming the metal fluoride layer on the pipe made of Hastelloy, and the supply time of the F2gas when forming the metal fluoride layer on the pipe made of SUS may be set longer than the supply time of the F2gas when forming the metal fluoride layer on the pipe made of Hastelloy.

According to the present disclosure in some embodiments, it is possible to improve the quality of substrate processing performed in the process container.