SUBSTRATE PROCESSING METHOD, RECORDING MEDIUM, AND SUBSTRATE PROCESSING APPARATUS

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 from a precursor gas supply line into a process chamber in which the substrate is accommodated; and (b) supplying a reaction gas into the process chamber in which the substrate is accommodated, wherein in (a), the precursor gas is divisionally supplied to the substrate a first plural number of times, the precursor gas is pre-filled in a storage installed in the precursor gas supply line and then supplied into the process chamber when the precursor gas is supplied for the first time, and an inside of the process chamber is exhausted before supplying the precursor gas for the second time.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-196816, filed on Nov. 27, 2020, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a substrate processing method, a recording medium, and a substrate processing apparatus.

BACKGROUND

In the related art, as a process for manufacturing a semiconductor device, there may be performed a substrate processing process in which a precursor gas or a reaction gas is supplied to a substrate to form a film on the substrate.

SUMMARY

Some embodiments of the present disclosure provide a technique capable of improving the step coverage or the in-plane film thickness uniformity of a film formed on a substrate.

According to one embodiment 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 from a precursor gas supply line into a process chamber in which the substrate is accommodated; and (b) supplying a reaction gas into the process chamber, wherein in (a), the precursor gas is divisionally supplied to the substrate a first plural number of times, the precursor gas is pre-filled in a storage installed in the precursor gas supply line and then supplied into the process chamber when the precursor gas is supplied for the first time, and an inside of the process chamber is exhausted before supplying the precursor gas for the second time.

DETAILED DESCRIPTION

One Embodiment of the Present Disclosure

Hereinafter, one embodiment of the present disclosure will be described mainly with reference toFIGS. 1 to 4. The drawings used in the following description are all schematic. The dimensional relationship of each element on the drawings, the ratio of each element, and the like may not always match the actual ones. Further, even between the drawings, the dimensional relationship of each element, the ratio of each element, and the like may not always match.

(1) Configuration of Substrate Processing Apparatus

As shown inFIG. 1, a process furnace202includes a heater207as a temperature regulator (heating part). The heater207has a cylindrical shape and is vertically installed by being supported by a holder. The heater207also functions as an activation mechanism (excitation part) that activates (excites) a gas with heat.

Inside the heater207, a reaction tube203is arranged concentrically with the heater207. The reaction tube203is made of a heat-resistant material such as, for example, quartz (SiO2) or silicon carbide (SiC) or the like, and is formed in a cylindrical shape with an upper end thereof closed and a lower end thereof opened. Below the reaction tube203, a manifold209is arranged concentrically with the reaction tube203. The manifold209is made of a metallic material such as stainless steel (SUS) or the like, and is formed in a cylindrical shape with upper and lower ends thereof opened. The upper end of the manifold209is engaged with the lower end of the reaction tube203and is configured to support the reaction tube203. An O-ring220aas a seal member is provided between the manifold209and the reaction tube203. The reaction tube203is installed vertically similar to the heater207. A process container (reaction container) is mainly composed of the reaction tube203and the manifold209. A process chamber201is formed in the hollow portion of the process container. The process chamber201is configured to accommodate wafers200as substrates. The wafers200are processed in the process chamber201.

Nozzles249ato249cas first to third supply parts are provided in the process chamber201so as to penetrate the side wall of the manifold209. The nozzles249ato249care also referred to as first to third nozzles, respectively. The nozzles249ato249care made of, for example, a heat-resistant material such as quartz or SiC. Gas supply pipes232ato232care connected to the nozzles249ato249c, respectively. The nozzles249ato249care different nozzles, and the nozzles249band249care provided adjacent to the nozzle249a.

In the gas supply pipe232a, a mass flow controller (MFC)241a, which is a flow rate controller (flow rate control part), a valve243aas a first valve, which is an opening/closing valve, a storage (gas reservoir)240aconfigured to temporarily store a gas, a valve242aas a second valve and a valve247aas a third valve are provided sequentially from the upstream side of a gas flow. A gas supply pipe232dis connected to the gas supply pipe232aon the downstream side of the valve247a. In the gas supply pipe232d, an MFC241dand a valve243dare provided sequentially from the upstream side of a gas flow. The gas supply pipes232aand232dand the storage240aare made of a metallic material such as stainless steel or the like.

The storage240ais configured as, for example, a gas tank or a spiral pipe having a gas capacity larger than that of an ordinary pipe. By opening and closing the valve243aon the upstream side of the storage240aand the valve242aon the downstream side of the storage240a, it is possible to perform filling the storage240awith the gas supplied from the gas supply pipe232aand supplying the gas filled in the storage240ainto the process chamber201. The conductance between the storage240aand the process chamber201may be set to be, for example, 1.5×10−3m3/s or more. Further, considering the ratio of a volume of the storage240ato a volume of the process chamber201, when the volume of the process chamber201is 100 L (liter), the volume of the storage240amay be set to, for example, 100 to 300 cc, or 1/1000 to 3/1000 times of the volume of the process chamber201.

By closing the valves242aand247aand opening the valve243a, the gas whose flow rate is adjusted by the MFC241acan be filled in the storage240a. When a predetermined amount of gas is filled in the storage240aand the pressure in the storage240areaches a predetermined pressure, by closing the valve243aand opening the valves242aand247a, a high-pressure gas filled in the storage240acan be supplied (flash-supplied) into the process chamber201at once (in a short time) via the gas supply pipe232aand the nozzle249a. The valve243amay be opened during flash supply.

In the gas supply pipes232band232c, MFCs241band241cand valves243band243c, which are opening/closing valves, are installed sequentially from the upstream side of a gas flow. A gas supply pipe232eis connected to the gas supply pipe232bon the downstream side of the valve243b. An MFC241eand a valve243eare provided in the gas supply pipe232esequentially from the upstream side of the gas flow. The gas supply pipes232b,232cand232eare made of a metallic material such as stainless steel or the like.

As shown inFIG. 2, the nozzles249ato249care provided in a space having an annular shape in a plan view between an inner wall of the reaction tube203and the wafers200such that the nozzles249ato249cextend upward along an arrangement direction of the wafers200from a lower portion to an upper portion of the inner wall of the reaction tube203. In other words, the nozzles249ato249care respectively installed in a region horizontally surrounding a wafer arrangement region in which the wafers200are arranged, at a lateral side of the wafer arrangement region so as to extend along the wafer arrangement region. In a plan view, the nozzle249ais disposed to face an exhaust port231ato be described below, on a straight line across the centers of the wafers200loaded into the process chamber201. The nozzles249band249care arranged so as to sandwich a straight line L passing through the nozzle249aand the center of the exhaust port231afrom both sides along the inner wall of the reaction tube203(the outer peripheral portions of the wafers200). The straight line L is a straight line passing through the nozzle249aand the center of the wafers200. The nozzle249cmay installed on the side opposite to the nozzle249bwith the straight line L interposed therebetween. The nozzles249band249care disposed line-symmetrically with the straight line L as an axis of symmetry. Gas supply holes250ato250cfor supplying gases are provided on a side surfaces of the nozzles249ato249c, respectively. The gas supply holes250ato250care respectively opened to face the exhaust port231ain a plan view and can supply gases toward the wafers200. The plurality of gas supply holes250ato250cis provided from the lower portion to the upper portion of the reaction tube203.

From the gas supply pipe232a, a precursor gas is supplied into the process chamber201via the MFC241a, the valve243a, the storage240a, the valves242aand247aand the nozzle249a.

From the gas supply pipe232b, a reaction gas is supplied into the process chamber201via the MFC241b, the valve243band the nozzle249b. The reaction gas is a substance having a molecular structure (chemical structure) different from that of the precursor gas.

From the gas supply pipes232dand232e, an inert gas is supplied into the process chamber201via the MFCs241dand241e, the valves243dand243e, the gas supply pipes232aand232b, and the nozzles249aand249b, respectively. Further, from the gas supply pipe232c, an inert gas is supplied into the process chamber201via the MFC241c, the valve243cand the nozzle249c. The inert gas acts as a purge gas, a carrier gas, a diluting gas and the like.

A precursor gas supply system (precursor gas supply line) is mainly composed of the gas supply pipe232a, the MFC241a, the valves243a,242aand247a, and the storage240a. A reaction gas supply system (reaction gas supply line) is mainly composed of the gas supply pipe232b, the MFC241band the valve243b. An inert gas supply system (inert gas supply line) is mainly composed of the gas supply pipes232cto232e, the MFCs241cto241eand the valves243cto243e. The precursor gas supply line may not be provided with the valve247a.

Each or both of the precursor gas and the reaction gas is also referred to as a film-forming gas, and each or both of the precursor gas supply system and the reaction gas supply system is also referred to as a film-forming gas supply system (film-forming gas supply line).

Some or all of the above-described various gas supply systems may be configured as an integrated gas supply system248in which the valves243a,242a,247aand243bto243e, the storage240a, the MFCs241ato241eand the like are integrated. The integrated gas supply system248is configured to be connected to each of the gas supply pipes232ato232esuch that the acts of supplying of various gases into the gas supply pipes232ato232e, i.e., the acts of opening or closing of the valves243a,242a,247aand243bto243e, the acts of flow rate adjusting by the MFCs241ato241e, and the like are controlled by the controller121which will be described later. The integrated gas supply system248is composed of integral type or a division type integrated units and may be attached to or detached from the gas supply pipes232ato232eand the like on the integrated unit basis. The integrated gas supply system248is configured to perform the maintenance, replacement, expansion, or the like on the integrated unit basis.

An exhaust port231afor exhausting the atmosphere in the process chamber201is provided in the lower portion of a side wall of the reaction tube203. As shown inFIG. 2, the exhaust port231ais provided at a position facing the nozzles249ato249c(gas supply holes250ato250c) with the wafers200interposed therebetween in a plan view. The exhaust port231amay be provided to extend from the lower portion to the upper portion of the side wall of the reaction tube203, i.e., along the wafer arrangement region. An exhaust pipe231is connected to the exhaust port231a. The exhaust pipe231is made of a metallic material such as stainless steel or the like. A vacuum pump246as a vacuum exhauster is connected to the exhaust pipe231via a pressure sensor245as a pressure detector (pressure detection part) for detecting the pressure inside the process chamber201and an APC (Auto Pressure Controller) valve244as a pressure regulator (pressure regulation part). The APC valve244is configured to be capable of performing or stopping vacuum exhausting of an interior of the process chamber201by opening or closing the valve in a state in which the vacuum pump246is operated. Furthermore, in a state in which the vacuum pump246is operated, the APC valve244is configured to be capable of regulating the pressure inside the process chamber201by adjusting a valve opening degree based on a pressure information detected by the pressure sensor245. An exhaust system is mainly composed of the exhaust pipe231, the APC valve244and the pressure sensor245. The vacuum pump246may be included in the exhaust system.

A seal cap219as a furnace opening lid capable of air-tightly closing a lower end opening of the manifold209is installed below the reaction tube203. The seal cap219is made of a metallic material such as, for example, stainless steel or the like, and is formed in a disc shape. On the upper surface of the seal cap219, an O-ring220bas a seal in contact with a lower end of the manifold209is installed. Below the seal cap219, a rotator267for rotating a boat217to be described later is installed. A rotating shaft255of the rotator267is made of, for example, a metallic material such as stainless steel or the like and is connected to the boat217through the seal cap219. The rotator267is configured to rotate the wafers200by rotating the boat217. The seal cap219is configured to be raised or lowered in the vertical direction by a boat elevator115as an elevator installed outside the reaction tube203. The boat elevator115is configured as a transfer device (transfer mechanism) that loads or unloads (transfers) the wafers200into and out of the process chamber201by raising or lowering the seal cap219.

Below the manifold209, a shutter219sis installed as a furnace opening lid capable of air-tightly closing the lower end opening of the manifold209in a state in which the seal cap219is lowered and the boat217is unloaded from the process chamber201. The shutter219sis made of a metallic material such as stainless steel or the like and is formed in a disk shape. On the upper surface of the shutter219s, an O-ring220cas a seal in contact with the lower end of the manifold209is installed. The opening/closing operations (the elevating operation, the rotating operation, or the like) of the shutter219sare controlled by a shutter opener/closer115s.

A boat217as a substrate support is configured to support a plurality of wafers200, for example, 25 to 200 wafers200in 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 each other, i.e., so as to arrange the wafers200at intervals. The boat217is made of a heat-resistant material such as, for example, quartz or SiC. Heat insulating plates218made of a heat-resistant material such as, for example, quartz or SiC, are supported in multiple stages at the bottom of the boat217.

Inside the reaction tube203, there is installed a temperature sensor263as a temperature detector. By adjusting a degree of conducting electricity to the heater207based on a temperature information detected by the temperature sensor263, the temperature inside the process chamber201becomes a desired temperature distribution. The temperature sensor263is installed along the inner wall of the reaction tube203.

As shown inFIG. 3, the controller121as a control part (control means) is configured as a computer including a CPU (Central Processing Unit)121a, a RAM (Random Access Memory)121b, a memory121cand an I/O port121d. The RAM121b, the memory121cand the I/O port121dare configured to exchange data with the CPU121avia an internal bus121e. An input/output device122configured as, for example, a touch panel or the like is connected to the controller121.

The memory121cis composed of, for example, a flash memory, an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like. A control program for controlling the operation of the substrate processing apparatus, a process recipe in which procedures, conditions, or the like of substrate processing to be described below, or the like are readably stored in the memory121c. The process recipe is a combination for causing the controller121to execute the respective procedures in a below-described substrate processing process so as to obtain a predetermined result. The process recipe functions as a program. Hereinafter, the process recipe, the control program and the like are collectively and simply referred to as a program. Furthermore, the process recipe is also simply referred to as a recipe. When the term “program” is used herein, it may mean 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 programs, data and the like read by the CPU121aare temporarily held.

The I/O port121dis connected to the MFCs241ato241e, the valves243a,242a,247aand243bto243e, the pressure sensor245, the APC valve244, the vacuum pump246, the temperature sensor263, the heater207, the rotator267, the boat elevator115, the shutter opener/closer115s, and the like.

The CPU121ais configured to read and execute the control program from the memory121cand to read the recipe from the memory121cin response to an input of an operation command from the input/output device122or the like. The CPU121ais configured to be capable of control, according to the contents of the read recipe, the flow rate adjustment operation of various gases by the MFCs241ato241e, the opening/closing operations of the valves243a,242a,247aand243bto243e, the opening/closing operation of the APC valve244, the pressure regulation operation by the APC valve244based on the pressure sensor245, the actuating and stopping of the vacuum pump246, the temperature control operation of the heater207based on the temperature sensor263, the rotation and the rotation speed adjustment operation of the boat217by the rotator267, the raising or lowering operation of the boat217by the boat elevator115, the opening/closing operation of the shutter219sby the shutter opener/closer115s, and the like.

The controller121may be configured by installing, in the computer, the above-described program stored in an external memory123. The external memory123includes, for example, a magnetic disk such as an HDD or the like, an optical disk such as a CD or the like, a magneto-optical disk such as an MO or the like, a semiconductor memory such as a USB memory, an SSD or the like, and so forth. The memory121cand the external memory123are configured as a computer readable recording medium. Hereinafter, the memory121cand the external memory123are collectively and simply referred to as a recording medium. As used herein, the term “recording medium” may include only the memory121c, only the external memory123, or both. The provision of the program to the computer may be performed by using a communication means such as the Internet or a dedicated line without having to use the external memory123.

(2) Substrate Processing Process

As a process of manufacturing a semiconductor device using the substrate processing apparatus described above, an example of a sequence in which a wafer200as a substrate is processed, i.e., an example of a film-forming sequence in which a film is formed on the wafer200, will be described mainly with reference toFIG. 4. In the present embodiment, there will be described an example in which a silicon substrate (silicon wafer) having recesses such as trenches or holes provided on the surface of the wafer200is used as the wafer200. In the following description, the operations of the respective parts constituting the substrate processing apparatus are controlled by the controller121.

In the film-forming sequence according to the present embodiment, a film is formed on a wafer200by performing a cycle a predetermined number of times (n times where n is an integer of 1 or more), the cycle including:

Step A of supplying a precursor gas from the precursor gas supply line into the process chamber201in which the wafer200having the recess provided on a surface thereof is accommodated; and Step B of supplying a reaction gas into the process chamber201in which the wafer200is accommodated.

In the film-forming sequence according to the present embodiment, in step A, the precursor gas is divisionally supplied to the wafer200a plurality of times (m times where m is an integer of 2 or more). When the precursor gas is supplied for the first time, the precursor gas is pre-filled in the storage240ainstalled in the precursor gas supply line and then supplied into the process chamber201. The inside of the process chamber201is exhausted before one or more subsequent supply of the precursor gas after the first supply of the precursor gas.FIG. 4shows a case where, for example, in step A, the precursor gas is divisionally and intermittently supplied to the wafer200three times (when m=3).

In the subject specification, the above-described film-forming sequence may be denoted as follows for the sake of convenience. The same notation is used in the following description of modifications or other embodiments.

As shown inFIG. 4, when step A and step B are alternately performed n times (where n is an integer of 1 or more), a step of purging the inside of the process chamber201may be interposed between step A and step B. Further, as shown inFIG. 4, when the precursor gas is supplied intermittently divided in m times (where m is an integer of 1 or more), after supplying the precursor gas in the first to m−1th time, the gas or the like remaining in the process chamber201may be removed by exhausting without performing a step of purging the inside of the process chamber201. The film-forming sequence in this case may be denoted as follows. Hereinafter, a term “purging” means that the precursor gas and intermediates existing in the process chamber201are removed by supplying an inert gas into the process chamber201. A term “exhaust” means that the precursor gas and intermediates existing in the process chamber201are removed without supplying an inert gas into the process chamber201. Further, the phrase “without supplying the inert gas” in the “exhaust” means that the purge gas is not supplied, but it also means that a carrier gas or a small amount of inert gas may be supplied.

When the term “wafer” is used herein, 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.” When the phrase “a surface of a wafer” is used herein, it may refer to “a surface of a wafer itself” or “a surface of a predetermined layer or the like formed on a wafer.” When the expression “a predetermined layer is formed on a wafer” is used herein, it 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.” When the term “substrate” is used herein, it may be synonymous with the term “wafer.”

(Wafer Charging and Boat Loading)

After a plurality of wafers200is charged to the boat217(wafer charging), the shutter219sis moved by the shutter opener/closer115sto open the lower end opening of the manifold209(shutter opening). Thereafter, as shown inFIG. 1, the boat217supporting the plurality of wafers200is lifted by the boat elevator115and loaded into the process chamber201(boat loading). In this state, the seal cap219seals the lower end of the manifold209via the O-ring220b.

(Pressure Regulation and Temperature Control)

After the boat loading is completed, the inside of the process chamber201, i.e., a space where the wafer200exists, is vacuum-exhausted (decompression-exhausted) by the vacuum pump246so that the pressure inside the process chamber201becomes a desired pressure (vacuum degree). In this operation, a pressure inside the process chamber201is measured by the pressure sensor245, and the APC valve244is feedback-controlled based on the measured pressure information (pressure regulation). Furthermore, the wafer200in the process chamber201is heated by the heater207to reach a desired processing temperature. In this operation, the degree of conducting electricity to the heater207is feedback-controlled based on the temperature information detected by the temperature sensor263so that the inside of the process chamber201has a desired temperature distribution (temperature control). Moreover, the rotation of the wafer200by the rotator267is started. The exhausting of the process chamber201and the heating and rotation of the wafer200are continuously performed at least until the processing on the wafer200is completed.

Thereafter, the following steps A and B are sequentially performed.

In this step, the precursor gas is divisionally supplied to the wafer200in the process chamber201a plurality of times. Specifically, step a1of supplying the precursor gas into the process chamber201and step a2of exhausting the inside of the process chamber201are alternately repeated a plurality of times (m times where m is an integer of 2 or more).

Before the first step a1, the valves242aand247aare closed, and the valve243ais opened to allow the precursor gas to flow into the gas supply pipe232a. The flow rate of the precursor gas is adjusted by the MFC241a, and the precursor gas is supplied into the storage240a. As a result, the storage240ais filled with the precursor gas. After the storage240ais filled with a predetermined amount of precursor gas, the valve243ais closed to maintain a state in which the storage240ais filled with the precursor gas.

In the first step a1, the valves247aand242aare opened in the named order or at the same time, and the high-pressure precursor gas filled in the storage240ais allowed to flow into the process chamber201at once. As a result, the precursor gas is supplied to the wafer200at once (flash supply of the precursor gas). In the flash supply, the precursor gas injected from the nozzle249ainto the process chamber201is accelerated to, for example, about the velocity of sound (340 m/sec) due to the pressure difference between the storage240aand the process chamber201. The velocity of the precursor gas on the wafer200reaches about several tens of m/sec. As shown inFIG. 4, a supply time in the flash supply may be shorter than a supply time in the non-flash supply in one or more subsequent steps a1after the first step a1described later. At this time, the valve243ais left to be opened. At this time, the valves243cto243emay be opened to supply the inert gas into the process chamber201via the nozzles249ato249c, respectively. Further, as shown inFIG. 4, this step may be performed in a state that the exhaust system substantially fully closed (APC valve244substantially fully closed). Herein, the state “substantially closed (substantially fully closed)” includes a state in which the APC valve244is opened about 0.1 to several % or a state in which, even if the APC valve244is controlled to be closed by 100%, the gas is exhausted to the exhaust system due to the performance of the APC valve244.

After the first step a1and before the one or more subsequent steps a1, the valves243a,242aand247aare closed. By closing the valves in this way, the precursor gas is prevented from being supplied into the storage240a.

In the one or more subsequent steps a1after the first step a1, the valves243a,242aand247aare opened to allow the precursor gas to flow into the gas supply pipe232a. The flow rate of the precursor gas is adjusted by the MFC241a. The precursor gas is supplied into the process chamber201via the valve243a, the storage240a, the valve242a, the valve247aand the nozzle249a. As a result, the precursor gas is supplied to the wafer200(non-flash supply of the precursor gas). In this step, the precursor gas may be supplied into the process chamber201without filling the storage240ain advance. In this case, a velocity of the precursor gas on the wafer200is smaller than that in the case of the flash supply. At this time, the valves243cto243emay be opened to supply the inert gas into the process chamber201via the nozzles249ato249c, respectively. The one or more subsequent steps a1after the first step a1are performed not in a state that the APC valve244is fully closed which means, for example, the APC valve244is in a state between a fully-opened state and a fully-closed state, so that a pressure inside the process chamber201becomes a predetermined pressure.

In step a2, the valves243a,242aand247aare closed to stop the supply of the precursor gas into the process chamber201. Then, the APC valve244is fully opened, for example, to exhaust the inside of the process chamber201, whereby the gas and the like remaining in the process chamber201are removed from the inside of the process chamber201. As shown inFIG. 4, in a final step a2among the steps a2performed a plurality of times, the inert gas may be supplied into the process chamber201to purge the inside of the process chamber201with the inert gas (purging). As shown inFIG. 4, an execution time of executing the final step a2among the steps a2performed a plurality of times may be the longest. Further, a flow rate of the inert gas supplied into the process chamber201in a final step a2among the steps a2performed a plurality of times, may larger than the flow rate of the inert gas supplied in the other steps a2.

As the precursor gas, for example, when a chlorosilane gas described later is used, by alternately repeating steps a1and a2a predetermined number of times under the processing conditions described later and divisionally supplying the chlorosilane gas to the wafer200a plurality of times, a silicon (Si)-containing layer containing Cl and having a predetermined thickness is formed, as a first layer, on the outermost surface of the wafer200as a base. The Si-containing layer containing Cl is formed on the outermost surface of the wafer200, by physical adsorption or chemical adsorption of molecules of the chlorosilane gas, by physical adsorption or chemical adsorption of molecules of a substance generated by a decomposition of a part of the chlorosilane gas, or by deposition of Si by thermal decomposition of the chlorosilane gas, or the like. The Si-containing layer containing Cl may be an adsorption layer (physical adsorption layer or chemical adsorption layer) of molecules of the chlorosilane gas or molecules of a substance generated by the decomposition of a part of the chlorosilane gas, or may be a deposition layer of Si containing Cl. When the above-mentioned chemical adsorption layer or the above-mentioned deposition layer is formed on the outermost surface of the wafer200, Si contained in the chlorosilane gas is adsorbed on the outermost surface of the wafer200. In the subject specification, the Si-containing layer containing Cl is also simply referred to as a Si-containing layer.

As the precursor gas, it may be possible to use, for example, a silane-based gas containing Si as a main element constituting the film formed on the wafer200. As the silane-based gas, it may be possible to use, for example, a gas containing Si and halogen, i.e., a halosilane-based gas. Halogen includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I) or the like. As the halosilane gas, it may be possible to use, for example, the chlorosilane gas containing Si and Cl.

As the precursor gas, it may be possible to use, for example, a chlorosilane gas such as a monochlorosilane (SiH3Cl, abbreviated as MCS) gas, a dichlorosilane (SiH2Cl2, abbreviated as DCS) gas, a trichlorosilane (SiHCl3, abbreviated as TCS) gas, a tetrachlorosilane (SiCl4, abbreviated as STC) gas, a hexachlorodisilane gas (Si2Cl6, abbreviated as HCDS) gas, an octachlorotrisilane (Si3Cl8, abbreviated as OCTS) gas, or the like. One or more of the above-mentioned gases may be used as the precursor gas.

As the precursor gas, in addition to the chlorosilane gas, it may be possible to use, for example, a fluorosilane gas such as a tetrafluorosilane (SiF4) gas, a difluorosilane (SiH2F2) gas or the like, a bromosilane gas such as a tetrabromosilane (SiBr4) gas, a dibromosilane (SiH2Br2) gas or the like, and an iodosilane gas such as a tetraiodosilane (SiI4) gas, a diiodosilane (SiH2I2) gas or the like. One or more of the above-mentioned gases may be used as the precursor gas.

As the precursor gas, in addition to these gases, it may be possible to use, for example, a gas containing Si and an amino group, i.e., an aminosilane gas. The amino group is a monovalent functional group obtained by removing hydrogen (H) from ammonia, a primary amine or a secondary amine, and may be represented as —NH2, —NHR or —NR2. In addition, R represents an alkyl group, and two Rs of —NR2may be the same or different.

As the precursor gas, it may be possible to use, for example, an aminosilane gas such as a tetrakis(dimethylamino)silane (Si[N(CH3)2]4, abbreviation: 4DMAS) gas, a tris(dimethylamino)silane (Si[N(CH3)2]3H, abbreviation: 3DMAS) gas, a bis(diethylamino)silane (Si[N(C2H5)2]2H2, abbreviation: BDEAS) gas, a bis(tertiary-butylamino)silane (SiH2[NH(C4H9)]2, abbreviation: BTBAS) gas, a (diisopropylamino)silane (SiH3[N(C3H7)2], abbreviation: DIPAS) gas or the like. One or more of the above-mentioned gases may be used as the precursor gas.

As the inert gas, it may be possible to use, for example, a nitrogen (N2) gas or a rare gas such as an argon (Ar) gas, a helium (He) gas, a neon (Ne) gas, a xenon (Xe) gas or the like. One or more of the above-mentioned gases may be used as the inert gas. This point is the same in each step described later.

After step A is completed, a reaction gas is supplied to the wafer200in the process chamber201, i.e., the Si-containing layer as the first layer formed on the wafer200.

Specifically, the valve243bis opened to allow the reaction gas to flow into the gas supply pipe232b. A flow rate of the reaction gas is adjusted by the MFC241b. The reaction gas is supplied into the process chamber201via the nozzle249band is exhausted from the exhaust port231a. At this time, the reaction gas is supplied to the wafer200(reaction gas supply). At this time, the valves243cto243emay be opened to supply the inert gas into the process chamber201via the nozzles249ato249c, respectively. In some of the methods described below, the supply of the inert gas into the process chamber201may not be performed.

As the reaction gas, for example, when a nitriding gas described later is used, by supplying the nitriding gas to the wafer200under the processing conditions described later, at least a part of the Si-containing layer formed on the wafer200is nitrided (modified). As a result, a silicon nitride layer (SiN layer) is formed on the outermost surface of the wafer200as a base as a second layer, which is a layer obtained by nitriding the Si-containing layer, i.e., a layer containing Si and N. When forming the SiN layer, impurities such as Cl and the like contained in the Si-containing layer form a gaseous substance containing at least Cl and are discharged from the inside of the process chamber201during the process of modifying the Si-containing layer with the nitriding gas. As a result, the SiN layer becomes a layer having fewer impurities such as Cl and the like than the Si-containing layer formed in step A.

After the SiN layer as the second layer is formed, the valve243bis closed to stop the supply of the nitriding gas into the process chamber201. Then, the gas or the like remaining in the process chamber201is removed from the process chamber201by the same processing procedure as in the purging in step A (purging).

As the reaction gas, it may be possible to use, for example, a nitrogen (N)- and hydrogen (H)-containing gas which is a nitriding gas (nitriding agent). The N- and H-containing gas is both an N-containing gas and an H-containing gas. The N- and H-containing gas may have an N—H bond.

As the reaction gas, it may be possible to use, for example, a hydrogen nitride-based gas such as an ammonia (NH3) gas, a diazene (N2H2) gas, a hydrazine (N2H4) gas, an N3H8gas or the like. One or more of the above-mentioned gases may be used as the reaction gas.

As the reaction gas, in addition to these gases, it may be possible to use, for example, a nitrogen (N)-, carbon (C)- and hydrogen (H)-containing gas. As the N-, C- and H-containing gas, it may be possible to use, for example, an amine-based gas or an organic hydrazine-based gas. The N, C and H-containing gas is also an N-containing gas, a C-containing gas, an H-containing gas, and an N- and C-containing gas.

As the reaction gas, it may be possible to use, for example, an ethylamine-based gas such as a monoethylamine (C2H5NH2, abbreviation: MEA) gas, a diethylamine ((C2H5)2NH, abbreviation: DEA) gas, a triethylamine ((C2H5)3N, abbreviation: TEA) gas or the like, a methylamine-based gas such as a monomethylamine (CH3NH2, abbreviation: MMA) gas, a dimethylamine ((CH3)2NH, abbreviation: DMA) gas, a trimethylamine ((CH3)3N, abbreviation: TMA) gas or the like, an organic hydrazine-based gas such as a monomethylhydrazine ((CH3)HN2H2, abbreviation: MMH) gas, a dimethylhydrazine ((CH3)2N2H2, abbreviation: DMH) gas, a trimethylhydrazine ((CH3)2N2(CH3)H, abbreviation: TMH) gas, and so forth. One or more of the above-mentioned gases may be used as the reaction gas.

[Performing a Predetermined Number of Times]

By performing the cycle including the above-described steps A and B a predetermined number of times (n times where n is an integer of 1 or more), for example, a silicon nitride film (SiN film) can be formed as a film on the surface of the wafer200. The above cycle may be repeated a plurality of times. That is, the thickness of the SiN layer formed per cycle is set to be thinner than a desired film thickness, and the above cycle may be repeated a plurality of times until the thickness of the SiN film formed by laminating the SiN layers becomes equal to the desired film thickness. At this time, in step A, the amount of the precursor gas pre-filled in the storage240amay be set to a constant amount for each cycle. Further, in the one or more subsequent cycles after the first cycle, the filling of the storage240awith the precursor gas in step A may be performed in parallel with the supplying of the reaction gas in step B one cycle before. When an N-, C- and H-containing gas is used as the reaction gas, for example, a silicon carbonitride layer (SiCN layer) can be formed as the second layer, and for example, a silicon carbonitride film (SiCN film) can be formed as a film on the surface of the wafer200by performing the above cycle a predetermined number of times.

The following are examples of the processing conditions in each of the above-described steps when, for example, the chlorosilane gas is used as the precursor gas and, for example, an N- and H-containing gas is used as the reaction gas. The notation of a numerical range such as “1 to 100 Pa” in the subject specification means that the lower limit value and the upper limit value are included in the range. Therefore, for example, “1 to 100 Pa” means “1 Pa or more and 100 Pa or less”. The same applies to other numerical ranges. In addition, the processing temperature in the subject specification means the temperature of the wafer200, and the processing pressure means the pressure in the process chamber201.

The processing conditions when performing step a1for the first time in step A are exemplified as follows.

The processing conditions when performing step a1for the one or more subsequent times after the first time in step A are exemplified as follows.

Other processing conditions may be the same processing conditions as those when performing step a1for the first time in step A.

The processing conditions when performing step a2for the first to m−1th time in step A are exemplified as follows.

Inert gas supply flow rate: 1000 to 20000 sccm

Other processing conditions may be the same processing conditions as those when performing step a1for the first time in step A.

The processing conditions when performing step a2for the last (mth) time in step A are exemplified as follows.

Inert gas supply flow rate: 1000 to 30000 sccm

Other processing conditions may be the same processing conditions as those when performing step a1for the first time in step A.

When step a2is performed for the last (mth) time in step A, the supply of the inert gas into the process chamber201and the exhausting of the process chamber201in a state in which the supplying of the inert gas into the process chamber201is stopped may be repeated a plurality of times. That is, when step a2is performed for the last (mth) time in step A, cycle purging may be performed.

The processing conditions in step B are exemplified as follows.

Other processing conditions may be the same processing conditions as those when performing step a1for the first time in step A.

(After-Purging and Atmospheric Pressure Restoration)

After the film having a desired thickness is formed on the wafer200, an inert gas as a purge gas is supplied into the process chamber201from each of the nozzles249ato249cand is exhausted from the exhaust port231a. As a result, the inside of the process chamber201is purged, and the gas, reaction by-products, or the like remaining in the process chamber201are removed from the inside of the process chamber201(after-purging). Thereafter, the atmosphere in the process chamber201is replaced with the inert gas (inert gas replacement), and the pressure in the process chamber201is restored to the atmospheric pressure (atmospheric pressure restoration).

Thereafter, the seal cap219is lowered by the boat elevator115to open the lower end of the manifold209. Then, the processed wafers200supported by the boat217are unloaded from the lower end of the manifold209to the outside of the reaction tube203(boat unloading). After the boat is unloaded, the shutter219sis moved and the lower end opening of the manifold209is sealed by the shutter219svia the O-ring220c(shutter closing). The processed wafers200are discharged out of the boat217after being unloaded from the reaction tube203(wafer discharging).

(3) Effects of the Present Embodiment

According to the present embodiment, one or more of the following effects may be obtained.

(a) In step A, the precursor gas is divisionally supplied to the wafer200a plurality of times. When the precursor gas is supplied for the first time, the precursor gas is pre-filled in the storage240ainstalled in the precursor gas supply line and then supplied into the process chamber201. Then, the inside of the process chamber201is exhausted before the one or more subsequent supply of the precursor gas after the first supply of the precursor gas. This makes it possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the wafer200.

This is because the precursor gas is supplied into the heated process chamber201and then decomposed to generate various intermediates. For example, as the precursor gas is decomposed, there are generated a first intermediate (e.g., SiCl2when the precursor gas is an HCDS gas) having a plurality of dangling bonds, a second intermediate (e.g., SiCl4when the precursor gas is an HCDS gas) having one dangling bond or no dangling bond, or the like. Then, these intermediates are supplied to the surface of the wafer200.

In this regard, the first intermediate has a plurality of dangling bonds. Therefore, the first intermediate has a characteristic that it is more easily adsorbed on the surface of the wafer200, i.e., a characteristic that a time required for the adsorption reaction of the first intermediate on the surface of the wafer200is shorter, when compared with the second intermediate having one dangling bond or no dangling bond. Further, the first intermediate having a plurality of dangling bonds has a characteristic that it can leave dangling bonds on the surface of the wafer200after being adsorbed on the surface of the wafer200and has a difficulty in inhibiting subsequent additional adsorption of intermediates or the like on the surface of the wafer200.

On the other hand, the second intermediate has a small number of dangling bonds or does not have dangling bonds. Therefore, the second intermediate has a characteristic that it is less likely to be adsorbed on the surface of the wafer200than the first intermediate having a plurality of dangling bonds, i.e., a characteristic that a time required for the adsorption reaction of the second intermediate on the surface of the wafer200is longer than that of the first intermediate. Further, the second intermediate having no multiple dangling bonds has a characteristic that it has a difficulty in leaving dangling bonds on the surface of the wafer200after being adsorbed on the surface of the wafer200and easily inhibits subsequent additional adsorption of intermediates or the like on the surface of the wafer200.

Due to the characteristics of the first intermediate and the second intermediate, the first intermediate is preferentially adsorbed on the surface of the wafer200. However, when the amount of the first intermediate is insufficient, the second intermediate is adsorbed on the wafer200and thereby the subsequent adsorption of the first intermediate is suppressed. As a result, the first intermediate cannot be uniformly adsorbed over the entire surface of the wafer200. In addition, when processing the wafer200having unevenness formed thereon, the first intermediate cannot be uniformly adsorbed over the entire area of the initial adsorption site on the surface in the recess. That is, it becomes a factor of deterioration of step coverage.

Such intermediates can be generated if it is a material that decomposes at the processing temperature. For example, the intermediates can be generated if it is the material of the above-described precursor gas. Particularly, if the gas contains halogen, the same result can occur. Specifically, MCS, DCS, TCS, STC and OCTS may be used besides HCDS.

In step A, the precursor gas is divisionally supplied to the wafer200a plurality of times. When the precursor gas is supplied for the first time, the precursor gas is pre-filled in the storage240ainstalled in the precursor gas supply line and then supplied into the process chamber201. That is, a large amount of precursor gas is supplied at once (flash supply) in a very short time. In this case, a large amount of the first intermediate can be supplied to the surface of the wafer200as compared with a case where the precursor gas is supplied into the process chamber201without being pre-filled in the storage240a(non-flash supply). As a result, the first intermediate can be uniformly adsorbed over the entire surface of the wafer200. In this way, at an initial stage of supplying the precursor gas, the first intermediate can be uniformly adsorbed over the entire area of an initial adsorption site on the outermost surface of the recess. As a result, as shown inFIG. 5A, a Si-containing layer having a uniform thickness over the entire area of the recess, i.e., a Si-containing layer having high step coverage, can be formed as an initial layer on the outermost surface of the recess. This layer may be a continuous layer or a discontinuous layer. In any case, the layer has high step coverage.

Further, by exhausting the inside of the process chamber201before the one or more subsequent supplying of the precursor gas after the first supplying of the precursor gas as in the present embodiment, the second intermediate generated in the process chamber201due to the supply of the precursor gas can be discharged to the outside of the process chamber201before being adsorbed on the surface of the wafer200, and can be prevented from adsorbing on the surface of the wafer200. As a result, as shown inFIG. 5B, it is possible to form a uniform and conformal first layer (Si-containing layer) over the entire area in the recess provided on the surface of the wafer200.

As a result, it is possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the substrate.

(b) In step A, when the precursor gas is supplied for the first time, an amount of the precursor gas pre-filled in the storage240amay be equal to or greater than an amount of the precursor gas required to adsorb the first intermediate over the entire surface of the wafer200. Thus, the first intermediate can be uniformly adsorbed over the entire surface of the wafer200, and the adsorption of the second intermediate on the surface of the wafer200can be suppressed. As a result, it is possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the wafer200.

(c) In step A, an amount of the precursor gas pre-filled in the storage240ais set to a constant amount for each of the cycle. This makes it possible to make uniform the thickness of the film formed on the wafer200per cycle, i.e., the cycle rate. As a result, it is possible to improve the controllability of the thickness of the film formed on the wafer200.

(d) In step A, when the precursor gas is supplied for the first time, the pressure in the process chamber201may be set to a pressure (predetermined pressure) equal to or greater than a pressure required to allow the first intermediate to be adsorbed over the entire surface of the wafer200. Thus, the first intermediate can be uniformly adsorbed over the entire surface of the wafer200, and the adsorption of the second intermediate on the surface of the wafer200can be suppressed. As a result, it is possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the wafer200.

(e) In step A, when the precursor gas is supplied for the first time, after a pressure in the process chamber201reaches a predetermined pressure, the supplying of the precursor gas into the process chamber201may be terminated and the exhausting of the process chamber201may be started. Thus, a time in which the pressure in the process chamber201is relatively high can be shortened, and the adsorption of the second intermediate on the surface of the wafer200can be suppressed. As a result, it is possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the wafer200.

(f) In step A, a supply time of the precursor gas when the precursor gas is supplied for the first time is set to be shorter than a supply time of the precursor gas when the precursor gas is supplied for the one or more subsequent times after the first time. This makes it possible to suppress the adsorption of the second intermediate on the surface of the wafer200. As a result, it is possible to improve the step coverage and the in-plane film thickness uniformity of the film formed on the wafer200.

(g) In step A, when the precursor gas is supplied for the first time, the precursor gas is supplied into the process chamber201in a state in which the exhaust system that exhausts the atmosphere in the process chamber201is substantially closed, i.e., a state in which the exhaust system is substantially fully closed. Thus, the pressure in the process chamber201can be quickly increased to a predetermined pressure required for allowing the first intermediate to be adsorbed over the entire surface of the wafer200in a short time. This makes it possible to shorten the cycle time and improve the productivity of the film-forming process.

(h) In step A, when the precursor gas is supplied for the one or more subsequent times after the first time, the precursor gas is supplied into the process chamber201without being filled in the storage240ain advance (non-flash supply). Thus, it is not necessary to fill the precursor gas into the storage240ain the one or more subsequent supply of the precursor gas after the first supply of the precursor gas. Therefore, a waiting time according to the filling of the precursor gas can be reduced as compared with a case where the precursor gas is filled into the storage240aeach time the precursor gas is supplied. As a result, it is possible to shorten the cycle time and improve the productivity of the film-forming process. In addition, the precursor gas stored during supplying the precursor gas for the first time can be suppressed from remaining in the storage240a. As a result, it is possible to suppress the generation of particles in the storage240a. For example, if the precursor gas stored when the precursor gas is supplied for the first time continues to remain in the storage240a, particles may be generated due to decomposition, aggregation, etc. of the precursor gas. By not filling the precursor gas into the storage240awhen the precursor gas is supplied for one or more subsequent times after the first time, it is possible to suppress the precursor gas from remaining in the storage240a.

(i) In step A, the supplying of the precursor gas when the precursor gas is supplied for one or more subsequent times after the first time may be terminated before the adsorption of the precursor gas on the wafer200reaches a saturated state. This makes it possible to suppress the adsorption of the second intermediate on the surface of the wafer200and to leave dangling bonds on the surface of the wafer200. As a result, the subsequent adsorption of intermediates or the like on the surface of the wafer200is not inhibited, and the deterioration of the step coverage or the in-plane film thickness uniformity of the film formed on the wafer200can be avoided.

When supplying the precursor gas for one or more subsequent times after the first time, if the supply of the precursor gas is continued until the adsorption of the precursor gas on the wafer200reaches a saturated state, the second intermediate is adsorbed on the surface of the wafer200, which makes it difficult to leave dangling bonds on the surface of the wafer200. As a result, the subsequent adsorption of additional intermediates or the like on the surface of the wafer200may be inhibited, which may deteriorate the step coverage or the in-plane film thickness uniformity of the film formed on the wafer200.

(j) In the one or more subsequent cycles after the first cycle, the filling of the precursor gas into the storage240ain step A is performed in parallel with step B. By doing so, it is possible to shorten the cycle time and improve the productivity of the film-forming process as compared with the case where the filling of the precursor gas into the storage240ais performed not parallel with step B. The same effect can be obtained when the filling of the precursor gas into the storage240ain the first cycle is performed before starting the film-forming process, for example, during performing the pressure regulation and temperature control described above.

(k) In step A, step a1of supplying the precursor gas into the process chamber201and step a2of exhausting the inside of the process chamber201are alternately repeated a plurality of times, whereby the second intermediates, particles or the like generated in the process chamber201can be discharged to the outside of the process chamber201before being adsorbed on the surface of the wafer200. As a result, it is possible to improve the step coverage, the in-plane film thickness uniformity and the film quality of the film formed on the wafer.

(l) In step A, the inert gas is supplied into the process chamber201when step a2of exhausting the inside of the process chamber201is performed for the last (mth) time. Thus, the undecomposed precursor gas or the like can be reliably discharged from the process chamber201before the reaction gas is supplied in step B, and the generation of particles in the process chamber201can be reliably suppressed. As a result, it is possible to improve the film quality of the film formed on the wafer200. When the inert gas is allowed to flow in all the plurality of steps a2as shown inFIG. 4, the above-mentioned effect can be surely achieved by maximizing the flow rate of the inert gas when step a2is performed for the last time.

In step A, when step a2of exhausting the inside of the process chamber201is performed for the first to m−1th time, the gas or the like remaining in the process chamber201are removed only by exhausting without supplying the inert gas into the process chamber201. The adsorption on the wafer200of the precursor gas supplied in the second to mth steps a1, particularly the adsorption in the recess of the wafer200can be prevented from being suppressed by the inert gas. As a result, it is possible to improve the film quality of the film formed on the wafer200. Further, it is possible to prevent the exhaust of the precursor gas supplied in step a1from being suppressed by the inert gas. That is, it is possible to reduce the possibility that the second intermediate among the intermediates generated by the decomposition or the like of the precursor gas supplied in step a1is adsorbed on the wafer200. As a result, it is possible to improve the film quality of the film formed on the wafer200. Particularly, the gas and the like remaining in the process chamber201may be removed only by exhausting without supplying the inert gas into the process chamber201during the first step a2.

(m) In step A, the execution time when step a2of exhausting the inside of the process chamber201is performed for the last time is the longest. Thus, the undecomposed precursor gas and the like can be reliably discharged from the process chamber201before the reaction gas is supplied in step B, and the generation of particles in the process chamber201can be reliably suppressed. As a result, it is possible to improve the film quality of the film formed on the wafer200.

(n) When filling the precursor gas into the storage240a, particles may be generated at a place where the pressure is high. By installing the valves243a,242aand247aas described above and performing the filling of the precursor gas into the storage240awhile opening the valve243aand closing the valve242a, it is possible to suppress the generation of particles in the valve247a. That is, it is possible to space the place of particle generation far away from the process chamber. As a result, it is possible to improve the film quality of the film formed on the wafer200.

Further, when the supplying of the precursor gas filled in the storage240ainto the process chamber201is performed by opening the valve242ain a state that the valve247ais opened, it is possible to suppress the generation of particles in the valve247a. That is, it is possible that the place of particle generation is far away from the process chamber.

In step A, for example, as shown inFIG. 4, a partial pressure of the precursor gas in the first step a1is set to be higher than a partial pressure of the precursor gas in the one or more subsequent steps a1after the first step a1. Since a large amount of precursor gas is flash-supplied in the first step a1, a large amount of the first intermediate can be supplied to the surface of the wafer200as compared with the non-flash supply in the one or more subsequent steps a1after the first step a1. As a result, the first intermediate can be uniformly adsorbed over the entire surface of the wafer200.

(o) The above-mentioned effects can be similarly obtained when using the above-mentioned various precursor gases, the above-mentioned reaction gases and the above-mentioned various inert gases. The above-mentioned effects can be remarkably obtained when a halosilane gas is used as the precursor gas. Further, the above-mentioned effects can be particularly remarkably obtained when a chlorosilane gas is used as the precursor gas.

Other Embodiments of the Present Disclosure

The embodiment of the present disclosure has been specifically described above. However, the present disclosure is not limited to the above-described embodiment, and various modifications may be made without departing from the gist thereof.

In the above-described embodiment, there has been described the case where, when the precursor gas is supplied for the first time in step A, the precursor gas is supplied into the process chamber201in a state in which the exhaust system for exhausting the atmosphere in the process chamber201is fully closed. However, the present disclosure is not limited thereto. For example, when the precursor gas is supplied for the first time in step A, the precursor gas may be supplied into the process chamber201in a state in which the exhaust system for exhausting the atmosphere in the process chamber201is fully opened. By doing so, it is possible to prevent the pressure in the process chamber201from rising excessively, suppress the generation of particles due to the aggregation, decomposition, etc. of the precursor gas, and improve the film quality of the film formed on the wafer200. Further, it is possible to shorten the time required for exhausting the inside of the process chamber201after the supply of the precursor gas is stopped, and improve the productivity of the film-forming process. Further, for example, when the precursor gas is supplied for the first time in step A, the valve opening degree of the APC valve244provided in the exhaust system for exhausting the atmosphere in the process chamber201may be set to a state between a fully-opened state and a fully-closed state. Specifically, the valve opening degree may be 0.1% to 99.9%, specifically about 50% to 80%. Thus, the exhaust system that exhausts the atmosphere in the process chamber201can be set to a state between a fully-opened state and a fully-closed state. As a result, the above-mentioned effects available when the exhaust system is fully closed and the above-mentioned effects available when the exhaust system is fully opened can be obtained in a well-balanced manner.

Further, in the above-described embodiment, there has been described the case where, as shown inFIG. 4, when the precursor gas is divisionally and intermittently m times (where m is an integer of 1 or more), after the precursor gas is supplied for the first to m−1th time, the gas or the like remaining in the process chamber201may be removed only by exhausting without performing the step of purging the inside of the process chamber201. However, the present disclosure is not limited thereto. For example, when the precursor gas is divisionally and intermittently m times (where m is an integer of 1 or more), after the precursor gas is supplied for the first to m−1th time, the inert gas may be supplied into the process chamber201to perform the step of purging the inside of the process chamber201. The film-forming sequence in this case may be denoted as follows.

Further, for example, when the precursor gas is divisionally and intermittently m times (where m is an integer of 1 or more), after the precursor gas is supplied in the first to m−1th time, the process chamber201may be exhausted and then the inert gas may be supplied into the process chamber201to perform the step of purging the inside of the process chamber201. The film-forming sequence in this case may be denoted as follows.

Further, in the final a2in step A, exhausting and purging may be performed in combination. The film-forming sequence in this case may be denoted as follows.

After the precursor gas is supplied for the first to m−1th time, step A may be performed as the step A in the film-forming sequence of the above-described embodiment. That is, after the supply of the precursor gas, one or both of exhausting and purging may be performed.

Further, after supplying the reaction gas in step B, exhausting and purging may be performed in combination. The film-forming sequence in this case may be denoted as follows.

Step A may be performed as the step A in the film-forming sequence of the above-described embodiment. That is, after the supply of the precursor gas, one or both of exhausting and purging may be performed.

Further, in the above-described embodiment, there has been described the case where, in the one or more subsequent cycles after the first cycle, the filling of the precursor gas into the storage240ain step A is performed in parallel with step B. However, the present disclosure is not limited thereto. For example, in the one or more subsequent cycles after the first cycle, the filling of the precursor gas into the storage240amay be started after the final supplying of the precursor gas in step A and before the supplying of the reaction gas in step B. By doing so, it is possible to further shorten the cycle time and further improve the productivity of the film-forming process.

Further, in the above-described embodiment, the chlorosilane gas has been described as an example of the precursor gas. However, the present disclosure is not limited thereto. For example, the present disclosure may be applied to a case where, by using a precursor gas containing a metal element such as aluminum (Al), titanium (Ti), hafnium (Hf), zirconium (Zr), tantalum (Ta), molybdenum (Mo), tungsten (W) or the like, a film containing a metal element, such as an aluminum nitride film (AlN film), a titanium nitride film (TiN film), a hafnium nitride film (HfN film), a zirconium nitride film (ZrN film), a tantalum nitride film (TaN film), a molybdenum nitride film (MoN), a tungsten nitride film (WN), an aluminum oxide film (AlO film), a titanium oxide film (TiO film), a hafnium oxide film (HfO film), a zirconium oxide film (ZrO film), a tantalum oxide film (TaO film), a molybdenum oxide film (MoO), a tungsten oxide film (WO), a titanium oxynitride film (TiON film), a titanium aluminum carbonitride film (TiAlCN film), a titanium aluminum carbide film (TiAlC film), a titanium carbon dioxide film (TiCN) or the like, is formed on a substrate by the above-described film-forming sequence. Even in these cases, at least a part of the effects described in the above-described embodiment may be obtained.

Moreover, in the above-described embodiment, for example, the N- and H-containing gas has been described as an example of the reaction gas. However, the present disclosure is not limited thereto. For example, a carbon (C)-containing gas such as an ethylene (C2H4) gas, an acetylene (C2H2) gas, a propylene (C3H6) gas or the like, a boron (B)-containing gas such as a diborane (B2H6) gas, a trichloroborane (BCl3) gas or the like, and an oxygen (O)-containing gas such as an oxygen (O2) gas, an ozone (O3) gas, a plasma-excited O2gas (O2*), O2gas+hydrogen (H2) gas, a water vapor (H2O gas), a hydrogen peroxide (H2O2) gas, a nitrous oxide (N2O) gas, a nitrogen monoxide (NO) gas, a nitrogen dioxide (NO2) gas, a carbon monoxide (CO) gas, a carbon dioxide (CO2) gas or the like may be used. In the subject specification, the parallel notation of two gases such as “O2gas+H2gas” means a mixed gas of a H2gas and an O2gas. When supplying a mixed gas, two gases may be mixed (premixed) in a supply pipe and then supplied into the process chamber201, or two gases may be supplied separately from different supply pipes into the process chamber201and mixed (post-mixed) in the process chamber201. As the reaction gas, one or more of the above-mentioned gases may be used. Even in these cases, at least a part of the effects described in the above-described embodiment may be obtained.

Further, in the above-described embodiment, there has been described the case where the SiN film or the SiCN film is formed on the wafer200in the substrate processing process. However, the present disclosure is not limited thereto. The present disclosure may also be applied a case where, in addition to the SiN film or the SiCN film, for example, a film containing Si, such as a silicon oxynitride film (SiON film), a silicon oxycarbide film (SiOC film), a silicon oxycarbonitride film (SiOCN film), a silicon borocarbonitride film (SiBCN film), a silicon boronitride film (SiBN film), a silicon oxide film (SiO film) or the like is formed. Even in these cases, at least a part of the effects described in the above-described embodiment may be obtained.

The recipe used for each process may be prepared separately according to the processing contents and may be stored in the memory121cvia an electric communication line or an external memory123. When starting each process, the CPU121amay properly selects an appropriate recipe from a plurality of recipes stored in the memory121caccording to the contents of the process. This makes it possible to form films of various film types, composition ratios, film qualities and film thicknesses with high reproducibility in one substrate processing apparatus. In addition, the burden on an operator can be reduced, and each process can be quickly started while avoiding operation errors.

The above-described recipes are not limited to the newly prepared ones, but may be prepared by, for example, changing the existing recipes already installed in the substrate processing apparatus. In the case of changing the recipes, the recipes after the change may be installed in the substrate processing apparatus via an electric communication line or a recording medium in which the recipes are recorded. In addition, the input/output device122provided in the existing substrate processing apparatus may be operated to directly change the existing recipes already installed in the substrate processing apparatus.

In the above-described embodiment, there has been described an example in which a film is formed using a batch type substrate processing apparatus for processing a plurality of substrates at a time. The present disclosure is not limited to the above-described embodiment, but may be suitably applied to, for example, a case where a film is formed using a single-wafer type substrate processing apparatus for processing one or several substrates at a time. Furthermore, in the above-described embodiment, there has been described an example in which a film is formed using a substrate processing apparatus having a hot wall type process furnace. The present disclosure is not limited to the above-described embodiment but may also be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold wall type process furnace.

Even in the case of using these substrate processing apparatuses, each process may be performed under the same processing procedures and processing conditions as those used in the above-described embodiment and modifications, and the same effects as those of the above-described embodiment and modifications may be obtained.

The above-described embodiment and modifications may be used in combination as appropriate. The processing procedures and processing conditions at this time may be the same as, for example, the processing procedures and processing conditions of the above-described embodiment or modifications.

According to the present disclosure in some embodiments, it is possible to provide a technique capable of improving the step coverage or the in-plane film thickness uniformity of the film formed on the substrate.