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

There is provided a technique that includes forming a film on at least one substrate by performing a cycle a predetermined number of times, the cycle including non-simultaneously performing: (a) performing a first set a number of times, the first set including non-simultaneously performing: supplying a precursor to the at least one substrate from at least one first ejecting hole of a first nozzle arranged along a substrate arrangement direction of a substrate arrangement region where the at least one substrate is arranged; and supplying a reactant to the at least one substrate; and (b) performing a second set a number of times, the second set including non-simultaneously performing: supplying the precursor to the at least one substrate from at least one second ejecting hole of a second nozzle arranged along the substrate arrangement direction of the substrate arrangement region; and supplying the reactant to the at least one substrate.

TECHNICAL FIELD

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

BACKGROUND

In the related art, as a process of manufacturing a semiconductor device, a substrate processing process of supplying a precursor or a reactant to substrates arranged and heated in a process chamber to form films on the substrates may be often carried out.

SUMMARY

When performing the above-mentioned process, an amount of precursors and the like supplied to the substrates, thermal history, and the like may become non-uniform among the substrates. As a result, an inter-substrate film thickness distribution of the films formed on the substrates may deviate from a desired distribution. Some embodiments of the present disclosure provide a technique capable of controlling an inter-substrate film thickness distribution of films formed on substrates arranged in a process chamber.

According to an embodiment of the present disclosure, there is provided a technique that includes: forming a film on at least one substrate by performing a cycle a predetermined number of times, the cycle including non-simultaneously performing: (a) performing a first set a predetermined number of times, the first set including non-simultaneously performing: supplying a precursor to the at least one substrate from at least one first ejecting hole of a first nozzle arranged along a substrate arrangement direction of a substrate arrangement region where the at least one substrate is arranged; and supplying a reactant to the at least one substrate; and (b) performing a second set a predetermined number of times, the second set including non-simultaneously performing: supplying the precursor to the at least one substrate from at least one second ejecting hole of a second nozzle arranged along the substrate arrangement direction of the substrate arrangement region; and supplying the reactant to the at least one substrate, wherein a structure of the first nozzle and a structure of the second nozzle are different from each other, and at least a portion of an installation region of the at least one first ejecting hole in the first nozzle and at least a portion of an installation region of the at least one second ejecting hole in the second nozzle overlap each other in the substrate arrangement direction.

DETAILED DESCRIPTION

<Embodiments of the Present Disclosure>

Embodiments of the present disclosure will be now described with reference toFIGS.1to4,FIG.7A, and the like.

(1) Configuration of Substrate Processing Apparatus

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

A reaction tube203is disposed inside the heater207to be concentric with the heater207. The reaction tube203is made of a heat resistant material, for example, quartz (SiO2), silicon carbide (SiC) and 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 a metal material, for example, stainless steel (SUS), and has a cylindrical shape with its upper and lower ends opened. The upper end of the manifold209engages with the lower end of the reaction tube203, and the manifold209is configured to support the reaction tube203. An O-ring220aas a seal member is installed between the manifold209and the reaction tube203. Similar to the heater207, the reaction tube203is vertically installed. A processing vessel (reaction vessel) mainly includes the reaction tube203and the manifold209. A process chamber201is formed in a hollow cylindrical portion of the processing vessel. The process chamber201is configured to be capable of accommodating wafers200as substrates. The processing of the wafers200is performed in the process chamber201.

Nozzles249ato249cas first to third supply parts are installed in the process chamber201to penetrate through a sidewall of the manifold209. The nozzles249ato249care made of, for example, a heat resistant material such as quartz and SiC. The nozzles249ato249care also referred to as first and third nozzles, respectively. Gas supply pipes232ato232care connected to the nozzles249ato249c, respectively. The nozzles249ato249care different nozzles, and each of the nozzles249aand249bis installed adjacent to the nozzle249cand is disposed to sandwich the nozzle249cfrom both sides thereof. The gas supply pipes232ato232cmay be included in the first to third supply parts, respectively.

Mass flow controllers (MFCs)241ato241c, which are flow rate controllers (flow rate control parts), and valves243ato243c, which are opening/closing valves, are installed at the gas supply pipes232ato232c, respectively, sequentially from an upstream side of gas flow. Gas supply pipes232dand232fare respectively connected to the gas supply pipe232aat a downstream side of the valve243a. Gas supply pipes232eand232gare respectively connected to the gas supply pipe232bat a downstream side of the valve243b. A gas supply pipe232his connected to the gas supply pipe232cat a downstream side of the valve243c. MFCs241dto241hand valves243dto243hare installed at the gas supply pipes232dto232h, respectively, sequentially from an upstream side of gas flow. The gas supply pipes232ato232hare made of the metal material, for example, stainless steel (SUS)

As illustrated inFIG.2, each of the nozzles249ato249cis disposed in an annular space (in a plane view) between an inner wall of the reaction tube203and the wafers200to installed from a lower portion to an upper portion of the inner wall of the reaction tube203, that is, along a wafer arrangement direction. Specifically, each of the nozzles249ato249cis installed at a region horizontally surrounding a wafer arrangement region in which the wafers200are arranged at a lateral side of a space where the wafers200are arranged (hereinafter, referred to as the wafer arrangement region), to extend along the wafer arrangement region. In the plane view, the nozzle249cis disposed to face an exhaust port231ato be described below in a straight line with centers of the wafers200loaded into the process chamber201interposed therebetween. The nozzles249aand249bare arranged adjacent to the nozzle249cwith a straight line passing through the nozzle249cand the exhaust port231ainterposed therebetween. In other words, the nozzles249aand249bare arranged on both sides of the nozzle249cwith the nozzle249cinterposed therebetween, that is, arranged to sandwich the nozzle249cbetween the both sides along the inner wall of the reaction tube203(an outer peripheral portion of the wafers200).

As illustrated inFIG.7A, each of the nozzles249ato249cis configured as a U-shaped nozzle (U-turn nozzle or return nozzle) having a portion bent in an inverted U shape (bent portion) at the top of the nozzles249ato249c, that is, above an upper end of the wafer arrangement region. First to third ejecting holes configured to supply (eject) a gas are arranged on the side surfaces of the nozzles249ato249calong the wafer arrangement direction. The first to third ejecting holes have a shape including a plurality of gas ejecting holes250ato250c, respectively. The plurality of gas ejecting holes250ato250care arranged from one end to the other end side of the wafer arrangement region in the wafer arrangement direction. Each of the gas ejecting holes250ato250cis opened to face the exhaust port231ain the plane view such that a gas can be supplied toward the wafers200. Shapes of the gas ejecting holes250ato250cviewed from the wafer arrangement region are circular, respectively.

The nozzles249ato249chave different structures from one another. Specifically, at least one selected from the group of opening areas of the first and second ejecting holes and shapes of the first and second ejecting holes are different from each other.

In the present embodiment, as an example, the opening area of each of the plurality of gas ejecting holes250aformed on a side surface of the nozzle249abecomes smaller as it goes from one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from a lower side toward an upper side of the wafer arrangement region). Further, the opening area of each of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249bbecomes larger as it goes from the one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). The opening area of each of the plurality of gas ejecting holes250cformed on the side surface of the nozzle249cis not particularly limited, but in the present embodiment, as an example, the opening area has a uniform size across a region from the one end to the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side to the upper side of the wafer arrangement region). In the present embodiment, the lower side of the wafer arrangement region corresponds to the downstream side of the gas flow in the nozzles249ato249cand the process chamber201, and the upper side of the wafer arrangement region corresponds to the upstream side of the gas flow in the nozzles249ato249cand the process chamber201.

Further, at least a portion of an installation region of the first ejecting holes of the nozzle249aand at least a portion of an installation region of the second ejecting holes of the nozzle249boverlap each other in the wafer arrangement direction.

In the present embodiment, as an example, the entire installation regions of the gas ejecting holes250ato250cin the nozzles249ato249coverlap one another in the wafer arrangement direction. The gas ejecting holes250ahaving the opening area set to be large in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be small in the nozzle249bare respectively arranged at height positions corresponding to each other in the wafer arrangement region, that is, at height positions corresponding to each other (similar height positions) on the lower side of the wafer arrangement region. Further, the gas ejecting holes250ahaving the opening area set to be small in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be large in the nozzle249bare respectively arranged at height positions corresponding to each other in the wafer arrangement region, that is, at height positions corresponding to each other (similar height positions) on the upper side of the wafer arrangement region.

A precursor (precursor gas), for example, a halosilane-based gas containing silicon (Si) as a main element forming a film to be formed and a halogen element, is supplied from the gas supply pipes232aand232binto the process chamber201via the MFCs241aand241b, the valves243aand243b, and the nozzles249aand249b, respectively. The precursor gas is a precursor in a gas state, for example, a gas obtained by vaporizing a precursor in a liquid state under normal temperature and normal pressure, a precursor in a gaseous state under normal temperature and normal pressure, and the like. The halosilane precursor refers to a silane precursor containing a halogen group. The halogen group includes a halogen element such as chlorine (Cl), fluorine (F), bromine (Br), and iodine (I). As the halosilane-based gas, for example, a precursor gas containing Si and Cl, that is, a chlorosilane-based gas, may be used. The chlorosilane-based gas acts as a Si source. As the chlorosilane-based gas, for example, a hexachlorodisilane (Si2Cl6, abbreviation: HCDS) gas may be used.

A reactant (reaction gas), for example, a nitrogen (N)-containing gas, is supplied from the gas supply pipe232cinto the process chamber201via the MFC241c, the valve243c, and the nozzle249c. The N-containing gas acts as a nitriding source (a nitriding agent or a nitriding gas), that is, as a N source. As the N-containing gas, for example, an ammonia (NH3) gas, which is a hydrogen nitride-based gas, may be used.

A reactant (reaction gas), for example, an oxygen (O)-containing gas, is supplied from the gas supply pipe232cinto the process chamber201via the MFC241c, the valve243c, and the nozzle249c. The O-containing gas acts as an oxidizing source (an oxidizing agent or an oxidizing gas), that is, as an O source. As the O-containing gas, for example, an oxygen (O2) gas may be used.

A hydrogen (H)-containing gas is supplied from the gas supply pipes232dand232einto the process chamber201via the MFCs241dand241e, the valves243dand243e, the gas supply pipes232aand232b, and the nozzles249aand249b, respectively. The H-containing gas alone does not have an oxidizing action, but in a substrate processing process to be described below, the H-containing gas reacts with the O-containing gas under a specific condition to generate oxidizing species such as atomic oxygen (O) to improve an efficiency of an oxidizing process. As the H-containing gas, for example, a hydrogen (H2) gas may be used.

An inert gas, for example, a nitrogen (N2) gas, is supplied from the gas supply pipes232fto232hinto the process chamber201via the MFCs241fto241h, the valves243fto243h, the gas supply pipes232ato232c, and the nozzles249ato249c, respectively. The N2gas acts as a purge gas or a carrier gas.

A first supply system configured to supply the precursor mainly includes the gas supply pipe232a, the MFC241a, the valve243a, and the nozzle249a. A second supply system configured to supply the precursor mainly includes the gas supply pipe232b, the MFC241b, the valve243b, and the nozzle249b. A third supply system configured to supply the reactant mainly includes the gas supply pipe232c, the MFC241c, the valve243c, and the nozzle249c. The third supply system may include the gas supply pipes232dand232e, the MFCs241dand241e, and the valves243dand243e. An inert gas supply system mainly includes the gas supply pipes232fto232h, the MFCs241fto241h, and the valves243fand243h.

One or all of the above-described various supply systems may be configured as an integrated supply system248in which the valves243ato243h, the MFCs241ato241hand the like are integrated. The integrated supply system248is connected to each of the gas supply pipes232ato232hand configured such that operations of supplying various gases into the gas supply pipes232ato232h, that is, an opening/closing operation of the valves243ato243h, a flow rate regulating operation by the MFCs241ato241h, and the like are controlled by a controller121to be described below. The integrated supply system248is configured as an integral or divided integration unit, and may be attached to and detached from the gas supply pipes232ato232hand the like on an integration unit basis such that maintenance, replacement, extension, and the like of the integrated supply system248may be performed on the integration unit basis.

The exhaust port231aconfigured to exhaust an internal atmosphere of the process chamber201is installed at a lower side of the sidewall of the reaction tube203. As illustrated inFIG.2, the exhaust port231ais installed at a position facing the nozzles249ato249c(the gas ejecting holes250ato250c) in the plane view, with the wafers200interposed therebetween. The exhaust port231amay be installed between the lower portion and the upper portion of the sidewall of the reaction tube203, that is, 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 the internal pressure of the process chamber201and an auto pressure controller (APC) valve244as a pressure regulator (pressure regulation part). The APC valve244is configured so that a vacuum exhaust and a vacuum exhaust stop of the interior of the process chamber201can be performed by opening and closing the APC valve244while operating the vacuum pump246and so that the internal pressure of the process chamber201can be regulated by adjusting an opening degree of the APC valve244based 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 vacuum pump246may be regarded as being included in the exhaust system.

A seal cap219, which serves as a furnace opening lid capable of hermetically sealing a lower end opening of the manifold209, is installed under the manifold209. The seal cap219is made of, for example, a metal material such as stainless steel (SUS), and is formed in a disc shape. An O-ring220b, which is a seal member making contact with a lower end of the manifold209, is installed at an upper surface of the seal cap219. A rotation mechanism267configured to rotate a boat217to be described below is installed under the seal cap219. A rotary shaft255of the rotation mechanism267is connected to the boat217through the seal cap219. 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 elevating mechanism installed outside the reaction tube203. The boat elevator115is configured as a transfer device (transfer mechanism) which loads/unloads (transfers) the wafers200into/out of the process chamber201by moving the seal cap219up or down. A shutter219s, which serves as a furnace opening lid capable of hermetically sealing a lower end opening of the manifold209in a state where the seal cap219is lowered and the boat217is unloaded from the process chamber201, is installed under the manifold209. The shutter219sis made of, for example, a metal material such as stainless steel (SUS), and is formed in a disc shape. An O-ring220c, which is a seal member making contact with the lower end portion of the manifold209, is installed on an upper surface of the shutter219s. The opening/closing operation (such as elevation operation and rotation operation) of the shutter219sis controlled by a shutter opening/closing mechanism115s.

The boat217serving as a substrate support is configured to support a plurality of wafers200, for example, 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, that is, the boat217is configured to arrange the wafers200to be spaced apart from one another. The boat217is made of a heat resistant material such as quartz and SiC. Heat insulating plates218made of a heat resistant material such as quartz and 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 degree of supplying electric power to the heater207is regulated 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.3, 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 memory121c, and an I/O port121d. The RAM121b, the memory121c, and the I/O port121dare configured to be capable of exchanging data with the CPU121avia an internal bus121e. An input/output device122configured as, for example, a touch panel and the like, is connected to the controller121.

The memory121cincludes, for example, a flash memory, a hard disk drive (HDD), and the like. A control program that controls operations of a substrate processing apparatus, a process recipe in which sequences, conditions and the like of substrate processing to be described below are described, and the like are readably stored in the memory121c. The process recipe functions as a program configured to be capable of causing the controller121to execute each sequence in the substrate processing to be described below, to obtain a predetermined result. Hereinafter, the process recipe, the control program, and the like will be generally and simply referred to as a “program.” Furthermore, the process recipe will 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 (a work area) in which a program, data, and the like read by the CPU121aare temporarily stored.

The I/O port121dis connected to the MFCs241ato241h, the valves243ato243h, 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 the control program from the memory121cand execute the same. The CPU121aalso reads the recipe from the memory121caccording to an input of an operation command from the input/output device122. In addition, the CPU121ais configured to control, according to the contents of the recipe thus read, the flow rate regulating operation of various kinds of gases by the MFCs241ato241h, the opening/closing operation of the valves243ato243h, the opening/closing operation of the APC valve244, the pressure regulating operation performed by the APC valve244based on the pressure sensor245, the driving and stopping of the vacuum pump246, the temperature regulating operation performed by the heater207based on the temperature sensor263, the operation of rotating the boat217and regulating the rotation speed of the boat217with the rotation mechanism267, the operation of moving the boat217up or down with the boat elevator115, the operation of opening and closing the shutter219swith 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 memory121cor the external memory device123is configured as a computer-readable recording medium. Hereinafter, the memory121cand the external memory device123will 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 memory121c, a case of including only the external memory device123, or a case of including both the memory121cand the external memory device123. Furthermore, the program may be supplied to the computer by using a communication means such as the Internet or a dedicated line, instead of using the external memory device123.

(2) Substrate Processing Process

As a process of manufacturing a semiconductor device by using the above-described substrate processing apparatus, a substrate processing sequence example of forming a film on a wafer200as a substrate, that is, a film-forming sequence example will be described with reference toFIG.4. In the following descriptions, operations of the respective parts constituting the substrate processing apparatus are controlled by the controller121.

In the film-forming sequence shown inFIG.4, a film containing Si and N, that is, a silicon nitride film (SiN film), is formed on a wafer200by performing a cycle a predetermined number of times (n3times, where n3is an integer of 1 or more), the cycle including non-simultaneously performing:

a first film-forming step of performing a first set a predetermined number of times (n1time, where n1is an integer of 1 or more), the first set including non-simultaneously performing: a step A1of supplying a HCDS gas as a precursor to the wafer200from first ejecting holes of a first nozzle arranged along a wafer arrangement direction of a wafer arrangement region, that is, a plurality of gas ejecting holes250aformed on the side surface of the nozzle249a; and a step A2of supplying a NH3gas as a reactant to the wafer200; and

a second film-forming step of performing a second set a predetermined number of times (n2time, where n2is an integer of 1 or more), the second set including non-simultaneously performing: a step B1of supplying the HCDS gas as the precursor to the wafer200from second ejecting holes of a second nozzle arranged along the wafer arrangement direction of the wafer arrangement region, that is, a plurality of gas ejecting holes250bformed on the side surface of the nozzle249b; and a step B2of supplying the NH3gas as the reactant to the wafer200.

When the film-forming sequence shown inFIG.4is performed, structures of the nozzles249aand249bconfigured to supply the HCDS gas to the wafer200are different as described above. Further, at least a portion of an installation region of the gas ejecting holes250ain the nozzle249aand at least a portion of an installation region of the gas ejecting holes250bin the nozzle249boverlap each other in the wafer arrangement region. Further, the NH3gas is supplied to the wafer200from third ejecting holes of a third nozzle, that is, a plurality of gas ejecting holes250cformed on the side surface of the nozzle249c.

FIG.4shows an example in which the number of times (n1) of performing the first set performed in the first film-forming step is one and the number of times (n2) of performing the second set performed in the second film-forming step is one. Further, inFIG.4, a performance period of the first film-forming step and a performance period of the second film-forming step are represented by A and B, respectively, for the sake of convenience. Further, inFIG.4, the nozzles249ato249care represented by R1 to R3, respectively, for the sake of convenience. The same notations of performance period of each step and each nozzle are used in inFIGS.5and6showing gas supply sequences of modifications to be described below. Further, inFIG.4, the performance periods of the steps A1, A2, B1, and B2are represented as A1, A2, B1, and B2, respectively, for the sake of convenience. The same applies toFIG.5to be described below.

In the present disclosure, for the sake of convenience, the film-forming sequence shown inFIG.4may be denoted as follows. The same denotations are used in modifications to be described below.
[(R1: HCDS→R3: NH3)×n1→(R2: HCDS→R3: NH3)×n2]×n3⇒SiN

When the term “wafer” is used in the present disclosure, it may refer to “a wafer itself” or “a wafer and a laminated body of certain layers or films formed on a surface of the wafer.” 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 certain layer and the like formed on a wafer”. When the expression “a certain layer is formed on a wafer” is used in the present disclosure, it may mean that “a certain layer is formed directly on a surface of a wafer itself” or that “a certain layer is formed on a layer and the like formed on a wafer.” When the term “substrate” is used in the present disclosure, it may be synonymous with the term “wafer.”

(Wafer Charging and Boat Loading)

The boat217is charged with a plurality of wafers200(wafer charging). Thereafter, as illustrated inFIG.1, the boat217charged with the plurality of wafers200is lifted up by the boat elevator115to be loaded into the process chamber201(boat loading). In this state, the seal cap219seals a lower end of the manifold209via the O-ring220b.

(Pressure Regulation and Temperature Regulation)

The interior of the process chamber201, that is, a space where the wafers200are placed, is vacuum-exhausted (decompression-exhausted) by the vacuum pump246to reach a desired pressure (processing pressure). In this operation, the internal pressure of the process chamber201is measured by the pressure sensor245, and the APC valve244is feedback-controlled based on the measured pressure information. Further, the wafers200in the process chamber201are heated by the heater207to have a desired temperature (processing temperature). In this operation, a degree of supplying electric power to the heater207is feedback-controlled based on the temperature information detected by the temperature sensor263so that the interior of the process chamber201has a desired temperature distribution. Further, the rotation of the wafers200by the rotation mechanism267begins. The exhaust of the interior of the process chamber201and the heating and rotation of the wafers200are continuously performed at least until the processing on the wafers200is completed.

Then, the following first and second film-forming steps are sequentially performed.

In a first film-forming step, the following steps A1and A2are sequentially performed.

In this step, a HCDS gas is supplied to the wafers200in the process chamber201(first HCDS gas supplying step). Specifically, the valve243ais opened to allow the HCDS gas to flow into the gas supply pipe232a. The flow rate of the HCDS gas is regulated by the MFC241a, and the HCDS gas is supplied into the process chamber201via each of the plurality of gas ejecting holes250aformed on the side surface of the nozzle249aand is exhausted via the exhaust port231a. At this time, at least one selected from the group of the valves243fto243hmay be opened to allow a N2gas to be supplied into the process chamber201via at least one selected from the group of the nozzles249ato249c.

A process condition in this step is exemplified as follows:

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

Each gas supply time: 1 to 120 seconds, specifically 1 to 60 seconds

In the present disclosure, a notation of a numerical range such as “250 to 800 degrees C.” means that a lower limit value and an upper limit value are included in the range. For example, “250 to 800 degrees C.” means “equal to or higher than 250 degrees C. and equal to or lower than 800 degrees C.” The same applies to other numerical ranges.

By supplying the HCDS gas to the wafer200under the above-mentioned condition, a Si-containing layer containing Cl is formed on the outermost surface of the wafer200. The Si-containing layer containing Cl is formed by depositing Si on the outermost surface of the wafer200, and the like when HCDS is physically adsorbed, when a substance (hereinafter, SixCly) obtained when a portion of HCDS is decomposed is chemically adsorbed, or when HCDS is thermally decomposed. The Si-containing layer containing Cl may be an adsorption layer of HCDS or SixCly(physisorption layer or chemisorption layer) or a Si layer containing Cl (Si deposition layer). In the present disclosure, the Si-containing layer containing Cl is also simply referred to as a Si-containing layer.

After the Si-containing 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 to remove a gas and the like remaining in the process chamber201from the interior of the process chamber201(purge step). At this time, the valves243fto243hare opened to allow a N2gas to be supplied into the process chamber201. The N2gas acts as a purge gas.

As the precursor (precursor gas), in addition to the HCDS gas, it may be possible to use, for example, a chlorosilane-based gas such as a monochlorosilane (SiH3Cl, abbreviation: MCS) gas, a dichlorosilane (SiH2Cl2, abbreviation: DCS) gas, a trichlorosilane (SiHCl3, abbreviation: TCS) gas, a tetrachlorosilane (SiCl4, abbreviation: STC) gas, and an octachlorotrisilane (Si3Cl8, abbreviation: OCTS) gas. The same applies to the step B1to be described below.

As the inert gas, in addition to the N2gas, a rare gas such as an Ar gas, a He gas, a Ne gas, and a Xe gas may be used. The same applies to each step to be described below.

After the step A1is completed, a NH3gas is supplied to the wafer200in the process chamber201, that is, the Si-containing layer formed on the wafer200(first NH3gas supplying step). Specifically, the valve243cis opened to allow the NH3gas to flow into the gas supply pipe232c. The flow rate of the NH3gas is regulated by the MFC241c, and the NH3gas is supplied into the process chamber201via each of the plurality of gas ejecting holes250cformed on the side surface of the nozzle249cand is exhausted via the exhaust port231a. In this operation, the NH3gas is supplied to the wafer200. At this time, at least one selected from the group of the valves243fto243hmay be opened to allow a N2gas to be supplied into the process chamber201via at least one selected from the group of the nozzles249ato249c.

A process condition in this step is exemplified as follows:

N2gas supply flow rate (per gas supply pipe): 0 to 2 slm

Other process conditions are the same as the process conditions in the step A1.

By supplying the NH3gas to the wafer200under the above-mentioned condition, at least a portion of the Si-containing layer formed on the wafer200is nitrided (modified). When the Si-containing layer is modified, a layer containing Si and N, that is, a SiN layer, is formed on the wafer200. When the SiN layer is formed, impurities such as Cl contained in the Si-containing layer constitute a gaseous substance containing at least Cl in the process of modifying the Si-containing layer with the NH3gas and is discharged from the process chamber201. As a result, the SiN layer becomes a layer having impurities such as Cl fewer than those in the Si-containing layer.

After the SiN layer is formed, the valve243cis closed to stop the supply of the NH3gas into the process chamber201. Then, according to the same process procedure as that in the purge step of the step A1, a gas and the like remaining in the process chamber201are removed from the inside of the process chamber201(purge step).

As the reactant (reaction gas), in addition to the NH3gas, for example, a hydrogen nitride-based gas such as diazene (N2H2) gas, a hydrazine (N2H4) gas, and a N3H8gas may be used. This same applies to the step B2to be described below.

[Performing First Set Predetermined Number of Times]

By performing a first set a predetermined number of times (n1time, where n1is an integer of 1 or more), the first set including non-simultaneously, that is, without synchronization, performing the steps A1and A2described above, a first SiN film having a predetermined composition and a predetermined film thickness can be formed on the wafer200.

After the first film-forming step is completed, the following steps B1and B2are sequentially performed.

In this step, the HCDS gas is supplied to the wafer200in the process chamber201, that is, the first SiN film formed on the wafer200(second HCDS gas supplying step). Specifically, the valve243bis opened to allow the HCDS gas to flow into the gas supply pipe232b. The flow rate of the HCDS gas is regulated by the MFC241b, and the HCDS gas is supplied into the process chamber201via each of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249band is exhausted via the exhaust port231a. Other process procedures are the same as those in the step A1. A process condition in this step is the same as the process condition in the step A1.

By supplying the HCDS gas to the wafer200under the above-mentioned condition, as in the step A1, a Si-containing layer is formed on the outermost surface of the wafer200, that is, on the first SiN film formed on the wafer200.

After the Si-containing layer is formed, the valve243bis closed to stop the supply of the HCDS gas into the process chamber201. Then, according to the same process procedure as that in the purge step of the step A1, a gas and the like remaining in the process chamber201are removed from the interior of the process chamber201(purge step).

After the step B1is completed, according to the same process procedures as that in the step A2, a NH3gas is supplied to the wafer200in the process chamber201, that is, the Si-containing layer formed on the first SiN film on the wafer200(second NH3gas supplying step). The process condition in this step is the same as the process condition in the step A2.

By supplying the NH3gas to the wafer200under the above-mentioned conditions, at least a portion of the Si-containing layer formed on the first SiN film on the wafer200is modified (nitrided), and as in the step A2, a SiN layer is formed on the outermost surface of the wafer200, that is, on the first SiN film formed on the wafer200

After the SiN layer is formed, the valve243cis closed to stop the supply of the NH3gas into the process chamber201. Then, according to the same process procedure as that in the purge step of the step A1, a gas and the like remaining in the process chamber201are removed from the process chamber201(purge step).

[Performing Second Set Predetermined Number of Times]

By performing a second set a predetermined number of times (n2time, where n2is an integer of 1 or more), the second set including non-simultaneously, that is, without synchronization, performing the steps B1and B2described above, a second SiN film having a predetermined composition and a predetermined film thickness can be formed on the wafer200, that is, on the first SiN film on the wafer200.

[Performing Cycle Predetermined Number of Times]

By performing a cycle a predetermined number of times (n3time, where n3is an integer of 1 or more), the cycle including non-simultaneously, that is, without synchronization, performing the first and second steps described above, a SiN film having a predetermined composition and a predetermined film thickness and including a laminated film in which the first SiN film and the second SiN film are alternately laminated can be formed on the wafer200.

(After-Purge and Returning to Atmospheric Pressure)

After the film-forming step is completed, a N2gas is supplied into the process chamber201from each of the gas supply pipes232fto232hand is exhausted from the exhaust pipe231via the exhaust port231a. The N2gas acts as a purge gas. Thus, the interior of the process chamber201is purged and a gas and reaction byproducts remaining in the process chamber201are removed from the interior of the process chamber201(after-purge). Thereafter, the internal atmosphere of the process chamber201is substituted with an inert gas (inert gas substitution) and the internal pressure of the process chamber201is returned to the atmospheric pressure (returning to atmospheric pressure).

The seal cap219is moved down 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). The processed wafers200are unloaded to the outside of the reaction tube203, and then are subsequently discharged from the boat217(wafer discharging).

(3) Effects of the Present Embodiment

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

(a) By supplying the HCDS gas to the wafer200from the nozzle249ain the step A1of the first film-forming step and supplying the HCDS gas to the wafer200from the nozzle249bhaving the structure different from that of the nozzle249ain the step B1of the second film-forming step, it is possible to control the inter-wafer film thickness distribution of the SiN film (laminated film) formed on the wafer200.

This is because, in the step A1, the HCDS gas is supplied to the wafer200from each of the gas ejecting holes250aconfigured such that the opening area gradually decreases from the lower side toward the upper side of the wafer arrangement region. In the step A1, the flow rate of the HCDS gas supplied to the wafer200decreases from one end toward the other end thereof of the wafer arrangement region in the wafer arrangement direction, that is, from the lower side toward the upper side of the wafer arrangement region, and therefore a flow velocity of the HCDS gas on the surface of the wafer200decreases, which increases a residence time of the HCDS gas on the surface of the wafer200. In the step A1, an amount of adsorption of Si contained in the HCDS gas on the surface of the wafer200increases from the lower side toward the upper side of the wafer arrangement region, which increases the thickness of the Si-containing layer formed on the wafer200. As a result, the inter-wafer film thickness distribution of the first SiN film formed on the wafer200by performing the first film-forming step is a distribution in which the film thickness gradually increases from the lower side toward the upper side of the wafer arrangement region.

Further, in the step B1, the HCDS gas is supplied to the wafer200from each of the gas ejecting holes250bconfigured such that the opening area gradually increases from the lower side toward the upper side of the wafer arrangement region. In the step B1, the flow rate of the HCDS gas supplied to the wafer200increases from one end toward the other end of the wafer arrangement region in the wafer arrangement direction, that is, from the lower side toward the upper side of the wafer arrangement region, and therefore the flow velocity of the HCDS gas on the surface of the wafer200increases, which decreases the residence time of the HCDS gas on the surface of the wafer200. In the step B1, the amount of adsorption of Si contained in the HCDS gas on the surface of the wafer200decreases from the lower side toward the upper side of the wafer arrangement region, which decreases the thickness of the Si-containing layer formed on the wafer200. As a result, the inter-wafer film thickness distribution of the second SiN film formed on the wafer200by performing the second film-forming step is a distribution in which the film thickness gradually decreases from the lower side toward the upper side of the wafer arrangement region.

In a case where the SiN film is formed on the wafer200by repeatedly laminating the first SiN film by performing only the first film-forming step a plurality of times while not performing the second film-forming step, the inter-wafer film thickness distribution of the SiN film formed on the wafer200becomes a distribution in which the film thickness gradually increases from the lower side toward the upper side of the wafer arrangement region. Further, in a case where the SiN film is formed on the wafer200by repeatedly laminating the second SiN film by performing only the second film-forming step a plurality of times while not performing the first film-forming step, the inter-wafer film thickness distribution of the SiN film formed on the wafer200becomes a distribution in which the film thickness gradually decreases from the lower side to the upper side of the wafer arrangement region.

In contrast, in the present embodiment, by alternately laminating the first and second SiN films having different inter-wafer film thickness distributions on the wafer200by performing a cycle a predetermined number of times, the cycle including non-simultaneously performing the first and second film-forming steps, it is possible to control the inter-wafer film thickness distribution of the SiN film formed on the wafer200. That is, it is possible to set the inter-wafer film thickness distribution of the SiN film formed on the wafer200to an intermediate distribution between the inter-wafer film thickness distribution of the SiN film formed on the wafer200by performing only the first film-forming step the predetermined number of times and the inter-wafer film thickness distribution of the SiN film formed on the wafer200by performing only the second film-forming step the predetermined number of times.

For example, by setting a ratio of a total film thickness of the first SiN film included in the SiN film to a total film thickness of the second SiN film included in the SiN film to a predetermined value, it is possible to have the inter-wafer film thickness distribution of the SiN film formed on the wafer200such that the thickness of the SiN film becomes uniform from the lower side to the upper side of the wafer arrangement region. That is, it is possible to improve the inter-wafer film thickness uniformity of the SiN film formed on the wafer200.

Further, for example, by setting the ratio of the total film thickness of the first SiN film included in the SiN film to the total film thickness of the second SiN film included in the SiN film to be larger than the above-mentioned ratio when the inter-wafer film thickness distribution is uniform, it is possible to control the inter-wafer film thickness distribution of the SiN film formed on the wafer200to approach the inter-wafer film thickness distribution of the SiN film formed on the wafer200by performing only the first film-forming step a plurality of times.

Further, for example, by setting the ratio of the total film thickness of the first SiN film included in the SiN film to the total film thickness of the second SiN film included in the SiN film to be smaller than the above-mentioned ratio when the inter-wafer film thickness distribution is uniform, it is possible to control the inter-wafer film thickness distribution of the SiN film formed on the wafer200to approach the inter-wafer film thickness distribution of the SiN film formed on the wafer200by performing only the second film-forming step a plurality of times.

(b) Since at least a portion of the installation region of the gas ejecting holes250ain the nozzle249aand at least a portion of the installation region of the gas ejecting holes250bin the nozzle249boverlap each other in the wafer arrangement direction, the above-mentioned effects can be obtained over a wide range of the wafer arrangement region in the wafer arrangement direction. In particular, as in the present embodiment, the entire installation regions of the gas ejecting holes250ato250cin the nozzles249ato249coverlap one another in the wafer arrangement direction, whereby the above-mentioned effects can be obtained in a wider range of the wafer arrangement region in the wafer arrangement direction, for example, in the entire region extending from the lower side to the upper side of the wafer arrangement region.

(c) By controlling the number of times (n1) of performing the first set in the first film-forming step, it is possible to control a degree of the inter-wafer film thickness distribution of the first SiN film formed on the wafer200over a wide range. For example, by setting n1to a large value, it is possible to increase the degree of the inter-wafer film thickness distribution in which the film thickness of the first SiN film gradually increases from the lower side toward the upper side of the wafer arrangement region. This control may be effective in a reaction system in which the SiN film formed on the wafer200tends to become thinner from the lower side toward the upper side of the wafer arrangement region. Further, by setting n1to a small value, it is possible to decrease the degree of the inter-wafer film thickness distribution in which the film thickness of the first SiN film gradually increases from the lower side toward the upper side of the wafer arrangement region.

Further, by controlling the number of times (n2) of performing the second set in the second film-forming step, it is possible to control the degree of the inter-wafer film thickness distribution of the second SiN film formed on the wafer200over a wide range. For example, by setting n2to a large value, it is possible to increase the degree of the inter-wafer film thickness distribution in which the film thickness of the second SiN film gradually decreases from the lower side to the upper side of the wafer arrangement region. This control may be effective in a reaction system in which the SiN film formed on the wafer200tends to become thicker from the lower side toward the upper side of the wafer arrangement region. Further, by setting n2to a small value, it is possible to decrease the degree of the inter-wafer film thickness distribution in which the film thickness of the second SiN film gradually decreases from the lower side toward the upper side of the wafer arrangement region.

From these points, by controlling the number of times (n1) of performing the first set in the first film-forming step and the number of times (n2) of performing the second set in the second film-forming step respectively, that is, by setting n1=n2, n1>n2, n1>>n2, n1<n2, or n1<<n2, it is possible to control the degree of the inter-wafer film thickness distribution of the SiN film finally formed on the wafer200over a wide range.

(d) The above-mentioned effects can be similarly obtained even when the above-mentioned precursor other than the HCDS gas is used, when the above-mentioned reactant other than the NH3gas is used, or when the above-mentioned inert gas other than the N2gas is used.

The present embodiment can be changed as in the following modifications. These modifications may be used in proper combination. Unless otherwise specified, a process condition and a process procedure in each step of each modification may be the same as the process condition and process procedure in each step of the film-forming sequence shown inFIG.4.

As illustrated inFIG.7B, long nozzles configured to extend upward in the wafer arrangement direction from the lower portion to the upper portion of the inner wall of the reaction tube203may be used as the nozzles249ato249c.

Further, in this modification, the opening areas of the plurality of gas ejecting holes250aformed on the side surface of the nozzle249adecrease gradually from one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249bincrease gradually from the one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250cformed on the side surface of the nozzle249chave a uniform size from the one end to the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side to the upper side of the wafer arrangement region). In this modification, the lower side of the wafer arrangement region corresponds to an upstream side of gas flow in the nozzles249ato249cand a downstream side of gas flow in the process chamber201, and the upper side of the wafer arrangement region corresponds to a downstream side of the gas flow in the nozzles249ato249cand an upstream side of the gas flow in the process chamber201.

Further, in this modification, the entire installation regions of the gas ejecting holes250ato250cin the nozzles249ato249coverlap one another in the wafer arrangement direction. The gas ejecting holes250ahaving the opening area set to be large in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be small in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the lower side of the wafer arrangement region. Further, the gas ejecting holes250ahaving the opening area set to be small in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be large in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the upper side the wafer arrangement region.

Further, in this modification, the same effects as those obtained when the nozzles249ato249cillustrated inFIG.7Aare used can be obtained.

As illustrated inFIG.8A, each of the plurality of gas ejecting holes250ato250cformed on the side surfaces of the nozzles249ato249cmay be formed in a slit shape. That is, the first to third ejecting holes may have a shape including a slit shape.

Further, in this modification, the opening areas of the plurality of gas ejecting holes250aformed on the side surface of the nozzle249adecrease gradually from one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249bincrease gradually from the one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250cformed on the side surface of the nozzle249chave a uniform size from the one end to the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side to the upper side of the wafer arrangement region). In this modification, the lower side of the wafer arrangement region corresponds to the downstream sides of gas flows in the nozzles249ato249cand the process chamber201, and the upper side of the wafer arrangement region corresponds to the upstream sides of gas flows in the nozzles249ato249cand the process chamber201.

Further, in this modification, the entire installation regions of the gas ejecting holes250ato250cin the nozzles249ato249coverlap each other in the wafer arrangement direction. The gas ejecting holes250ahaving the opening area set to be large in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be small in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the lower side of the wafer arrangement region. Further, the gas ejecting holes250ahaving the opening area set to be small in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be large in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the upper side of the wafer arrangement region.

Further, in this modification, one of (i) the gas ejecting holes250ain the nozzle249aand (ii) the gas ejecting holes250bin the nozzle249bmay have a shape including a slit shape, and the other one different from the one of (i) and (ii) may have a shape including a circular shape.

Further, in this modification, the same effects as those obtained when the nozzles249ato249cillustrated inFIG.7Aare used can be obtained.

As illustrated inFIG.8B, long nozzles configured to extend upward in the wafer arrangement direction from the lower portion to the upper portion of the inner wall of the reaction tube203may be used as the nozzles249ato249c, and each of the gas ejecting holes250ato250cmay be formed in the slit shape.

Further, in this modification, the opening areas of the plurality of gas ejecting holes250aformed on the side surface of the nozzle249adecrease gradually from one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249bincrease gradually from the one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region). Further, the opening areas of the plurality of gas ejecting holes250cformed on the side surface of the nozzle249care not particularly limited, but for example, the opening area have a uniform size from the one end to the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region).

Further, in this modification, the entire installation regions of the gas ejecting holes250ato250cin the nozzles249ato249coverlap each other in the wafer arrangement direction. The gas ejecting holes250ahaving the opening area set to be large in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be small in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the lower side of the wafer arrangement region. Further, the gas ejecting holes250ahaving the opening area set to be small in the nozzle249aand the gas ejecting holes250bhaving the opening area set to be large in the nozzle249bare respectively arranged at the height positions corresponding to each other in the wafer arrangement region, that is, at the height positions corresponding to each other (similar height positions) on the upper side of the wafer arrangement region.

Further, in this modification, one of (i) the gas ejecting holes250ain the nozzle249aand (ii) the gas ejecting holes250bin the nozzle249bmay have a shape including a slit shape, and the other one different from the one of (i) and (ii) may have a shape including a circular shape.

Further, in this modification, the same effects as those obtained when the nozzles249ato249cillustrated inFIG.7Aare used can be obtained.

The opening areas of the plurality of gas ejecting holes250aformed on the side surface of the nozzle249amay decrease gradually from one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region), like the opening areas of the gas ejecting holes250ain the nozzle249aillustrated inFIGS.7A,7B,8A, and8B, and the opening areas of the plurality of gas ejecting holes250band250cformed on the side surfaces of the nozzles249band249cmay have a uniform size from the one end toward the other end side of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region), like the opening areas of the gas ejecting holes250cin the nozzle249cillustrated inFIGS.7A,7B,8A, and8B.

Further, for example, the opening areas of the plurality of gas ejecting holes250bformed on the side surface of the nozzle249bmay increase gradually from the one end toward the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side of the wafer arrangement region), like the opening areas of the gas ejecting holes250bin the nozzle249billustrated inFIGS.7A,7B,8A, and8B, and the opening areas of the plurality of gas ejecting holes250aand250cformed on the side surfaces of the nozzles249aand249cmay have a uniform size from the one end to the other end of the wafer arrangement region in the wafer arrangement direction (here, from the lower side toward the upper side thereof of the wafer arrangement region), like the opening areas of the gas ejecting holes250cin the nozzle249cillustrated inFIGS.7A,7B,8A, and8B.

Further in this modification, the same effects as those obtained when the nozzles249ato249cillustrated inFIG.7Aare used can be obtained.

As in a film-forming sequence shown inFIG.5and below, in each of the steps A2and B2, an O2gas may be supplied to the wafer200from the nozzles249c, and a H2gas may be supplied to the wafer200from the nozzles249aand249b. The H2gas may be supplied from at least one selected from the group of the nozzles249aand249b. The steps A1and B1are performed in the same manner as the steps A1and B1of the film-forming sequence shown inFIG.4.
[(R1: HCDS→R3: O2+R1, R2: H2)×n1→(R2: HCDS→R3: O2+R1, R2: H2)×n2]×n3⇒SiO

According to this modification, a film containing Si and O, that is, a silicon oxide film (SiO film), may be formed as a film on the wafer200. Further, in this modification, the same effects as those of the film-forming sequence shown inFIG.4can be obtained.

The configuration of the gas supply system may be changed to supply a HCDS gas to the wafer200from the gas supply pipe232cand supply a NH3gas and an O2gas to the wafer200from the gas supply pipes232aand232b, respectively.

Then, as in a film-forming sequence shown inFIG.6and below, in the first film-forming step, a first set may be performed a predetermined number of times (n1time, where n1is an integer of 1 or more), and the first set may include non-simultaneously performing: a step of supplying a HCDS gas to the wafer200from the nozzle249c; a step of supplying a NH3gas to the wafer200from the nozzles249aand249b; and a step of supplying an O2gas to the wafer200from the nozzle249a. Further, in the second film-forming step, a second set may be performed a predetermined number of times (n2time, where n2is an integer of 1 or more), and the second set may include non-simultaneously performing: a step of supplying a HCDS gas to the wafer200from the nozzle249c; a step of supplying a NH3gas to the wafer200from the nozzles249aand249b; and a step of supplying an O2gas to the wafer200from the nozzle249b. The NH3gas may be supplied from at least one selected from the group of the nozzles249aand249b.

By performing the first film-forming step, a film containing Si, O, and N, that is, a first SiON film, may be formed on the wafer200. Further, by performing the second film-forming step, a film containing Si, O, and N, that is, a second SiON film, may be formed on the wafer200, that is, on the first SiON film on the wafer200. According to this modification, a SiON film having a predetermined composition and a predetermined film thickness and including a laminated film in which the first SiON film and the second SiON film are alternately laminated can be formed as a film on the wafer200.
[(R3: HCDS→R1, R2: NH3→R1: O2)×n1→(R3: HCDS→R1, R2: NH3→R2: O2)×n2]×n3⇒SiON

According to this modification, by performing the first film-forming step, it is possible to set an inter-wafer composition distribution of the first SiON film formed on the wafer200to a distribution in which the degree of oxidation by the O2gas gradually increases from the lower side toward the upper side of the wafer arrangement region and a content (residual amount) of N in the film gradually decreases, that is, a composition distribution in which N becomes poorer and poorer from the lower side toward the upper side of the wafer arrangement region. Further, by performing the second film-forming step, it is possible to set an inter-wafer composition distribution of the second SiON film formed on the wafer200to a distribution in which the degree of oxidation by the O2gas gradually decrease from the lower side toward the upper side of the wafer arrangement region and the content (residual amount) of N in the film gradually increases, that is, a composition distribution in which N becomes richer and richer from the lower side toward the upper side of the wafer arrangement region.

In this modification, by alternately laminating the first and second SiON films having different inter-wafer composition distributions on the wafer200by performing a cycle a predetermined number of times (the cycle including non-simultaneously performing the first and second film-forming steps), it is possible to control the inter-wafer composition distribution of the SiON film finally formed on the wafer200. That is, it is possible to set the inter-wafer composition distribution of the SiON film finally formed on the wafer200to an intermediate distribution between the inter-wafer composition distribution of the SiON film formed on the wafer200by performing only the first film-forming step a predetermined number of times and the inter-wafer composition distribution of the SiON film formed on the wafer200by performing only the second film-forming step a predetermined number of times.

For example, by setting a ratio of a total film thickness of the first SiON film included in the SiON film to a total film thickness of the second SiON film included in the SiON film to a predetermined value, it is possible to make the inter-wafer composition distribution of the SiON film formed on the wafer200uniform from the lower side to the upper side of the wafer arrangement region. That is, it is possible to improve the inter-wafer composition uniformity of the SiON film formed on the wafer200.

Further, for example, by setting the ratio of the total film thickness of the first SiON film included in the SiON film to the total film thickness of the second SiON film included in the SiON film to be larger than the above-mentioned ratio when the inter-wafer composition distribution is uniform, it is possible to control the inter-wafer composition distribution of the SiON film formed on the wafer200to approach the inter-wafer composition distribution of the SiON film formed on the wafer200by performing only the first film-forming step a predetermined number of times.

Further, for example, by setting the ratio of the total film thickness of the first SiON film included in the SiON film to the total film thickness of the second SiON film included in the SiON film to be smaller than the above-mentioned ratio when the inter-wafer composition distribution is uniform, it is possible to control the inter-wafer composition distribution of the SiON film formed on the wafer200to approach the inter-wafer composition distribution of the SiON film formed on the wafer200by performing only the second film-forming step a predetermined number of times.

As in a film-forming sequence described below, a cycle including non-simultaneously performing a step of simultaneously supplying a HCDS gas to the wafer200from the nozzles249aand249b; and a step of supplying a NH3gas to the wafer200from the nozzles249cmay be performed a predetermined number of times (n times, where n is an integer of 1 or more). Further, in this modification, the same effects as those of the film-forming sequence shown inFIG.4can be obtained. Further, according to this modification, by regulating a flow rate balance of the HCDS gas supplied from the nozzles249aand249b, it is possible to control the inter-wafer film thickness distribution in a wide range. Further, a cycle including non-simultaneously performing the first film-forming step of the film-forming sequence shown inFIG.4, the second film-forming step of the film-forming sequence shown inFIG.4, and the film-forming sequence of this modification may be performed a predetermined number of times.
(R1, R2: HCDS→R3: NH3)×n⇒SiN

Other Embodiments

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

For example, as the precursor, it may be possible to use, e.g., an aminosilane-based gas such as a tris(dimethylamino)silane (SiH[N(CH3)2]3, abbreviation: 3DMAS) gas and a bis(diethylamino)silane (SiH2[N(C2H5)2]2, abbreviation: BDEAS) gas.

Further, for example, as the reactant, it may be possible to use a carbon (C)-containing gas such as a propylene (C3H6) gas, a gas containing N and C such as a triethylamine ((C2H5)3N, abbreviation: TEA) gas, a boron (B)-containing gas such as a trichloroborane (BCl3) gas, or an O-containing gas such as an ozone (O3) gas and a plasma-excited oxygen (O2) gas (O2*).

Then, for example, according to film-forming sequences described below, the present disclosure may also be applied to a case of forming a Si-containing film such as a SiON film, a silicon oxycarbide film (SiOC film), a silicon oxycarbonitride film (SiOCN film), a silicon carbonitride film (SiCN film), a silicon borocarbonitride film (SiBCN film), and a silicon boronitride film (SiBN film) on the substrate. Further, in these cases, the same effects as those of the above-described embodiments can be obtained. A process procedure and a process condition when the precursor and the reactants are supplied may be, for example, the same as those in each step of the above-described embodiments.
[(R1: HCDS→R3: NH3→R3: O2)×n1→(R2: HCDS→R3: NH3→R3: O2)×n2]×n3⇒SiON
[(R1: HCDS→R3: TEA→R3: O2)×n1→(R2: HCDS→R3: TEA→R3: O2)×n2]×n3⇒SiOC(N)
[(R1: HCDS→R3: C3H6→R3: NH3)×n1→(R2: HCDS→R3: C3H6→R3: NH3)×n2]×n3⇒SiCN

Further, for example, the present disclosure may be applied to a case of using a titanium tetrachloride (TiCl4) gas, a trimethylaluminum (Al(CH3)3, abbreviation: TMA) gas, and the like as a precursor to form a film containing a metal element such as a titanium nitride film (TiN film), a titanium oxynitride film (TiON film), a titanium aluminum carbonitride film (TiAlCN film), a titanium aluminum carbide film (TiAlC film), a titanium carbonitride film (TiCN film), and a titanium oxide film (TIO film) on a substrate. Further, in these cases, the same effects as those of the above-described embodiments may be obtained.

Further, for example, the present disclosure may be applied to a case of performing an oxidizing process such as dry oxidation, wet oxidation, or plasma oxidation of a surface of a substrate, or a nitriding process such as thermal nitridation or plasma nitridation of the surface of the substrate. Further, in these cases, the same effects as those of the above-described embodiments can be obtained.

Recipes used in the substrate processing may be provided individually according to the processing contents and may be stored in the memory121cvia a telecommunication line or the external memory device123. Moreover, at the beginning of the substrate processing, the CPU121amay properly select an appropriate recipe from the recipes stored in the memory121caccording to the contents of the substrate processing. Thus, it is possible for a single substrate processing apparatus to form films of various kinds, composition ratios, qualities, and thicknesses with enhanced reproducibility. Further, it is possible to reduce an operator's burden and to quickly start the substrate processing while avoiding an operation error.

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

In the above-described embodiments, an example has been described in which the first to third nozzles (the nozzles249ato249c) as the first to third supply parts are provided in the process chamber along the inner wall of the reaction tube. However, the present disclosure is not limited to the above-described embodiments. For example, as illustrated in the cross-sectional structure of the vertical process furnace inFIG.9A, a buffer chamber is provided at the sidewall of the reaction tube, and the first to third nozzles having the same configurations as the above-described embodiments may be provided in the buffer chamber in the same arrangement as those of the above-described embodiments.FIG.9Ashows an example in which a supply buffer chamber and an exhaust buffer chamber are provided at the sidewall of the reaction tube and are respectively arranged at opposing positions with a wafer interposed therebetween. Each of the supply buffer chamber and the exhaust buffer chamber is provided from the lower portion to the upper portion of the sidewall of the reaction tube, that is, along the wafer arrangement region. Further,FIG.9Ashows an example in which the supply buffer chamber is partitioned into a plurality of (three) spaces and the nozzles are arranged in the space respectively. The arrangement of the three spaces in the buffer chamber is the same as the arrangement of the first to third nozzles. The spaces in which the first to third nozzles are arranged may also be referred to as first to third buffer chambers, respectively. The first nozzle and the first buffer chamber, the second nozzle and the second buffer chamber, and the third nozzle and the third buffer chamber may be considered as a first supply part, a second supply part, and a third supply part, respectively. Further, for example, as illustrated in the cross-sectional structure of the vertical process furnace inFIG.9B, the buffer chamber may be provided in the same arrangement as that inFIG.9A, the third nozzle may be provided in the buffer chamber, and the first and second nozzles may be provided along the inner wall of the reaction tube while interposing a communication part of the buffer chamber with the process chamber from both sides. The first nozzle, the second nozzle, and the third nozzle, and the buffer chamber may be considered as the first supply part, the second supply part, and the third supply part, respectively. The configurations other than the buffer chamber and the reaction tube described inFIGS.9A and9Bare the same as the configurations of the respective parts of the process furnace illustrated inFIG.1. Even when these process furnaces are used, the same substrate processing as that of the above-described embodiments may be performed, and the same effects as those of the above-described embodiments can be obtained.

The example in which a film is formed by using a batch-type substrate processing apparatus capable of processing a plurality of substrates at a time has been described in the above-described embodiments. The present disclosure is not limited to the above-described embodiments, but may be suitably applied, for example, to a case where a film is formed by using a single-wafer type substrate processing apparatus capable of processing a single substrate or several substrates at a time. In addition, the example in which a film is formed by using a substrate processing apparatus provided with a hot-wall-type process furnace has been described in the above-described embodiments. The present disclosure is not limited to the above-described embodiments, but may be suitably applied to a case where a film is formed by using a substrate processing apparatus provided with a cold-wall-type process furnace.

Even in the case of using these substrate processing apparatuses, substrate processing may be performed according to the same sequences and process conditions as those in the above-described embodiments and modifications, and the same effects as those of the above-described embodiments and modifications can be obtained.

The above-described embodiments and modifications may be used in proper combination. The process procedures and process conditions used in that case may be the same as, for example, the process procedures and process conditions of the above-described embodiments.

Examples

As Example 1, the substrate processing apparatus illustrated inFIG.1is used to form a SiN film on wafers arranged in the process chamber by the film-forming sequence shown inFIG.4, that is, a film-forming sequence of alternately supplying a HCDS gas to the wafers from the first and second nozzles and supplying a NH3gas to the wafers from the third nozzle. The first to third nozzles have the shapes of the nozzles illustrated inFIG.7A.

As Example 2, the substrate processing apparatus used in Example 1 is used to form a SiN film on wafers arranged in the process chamber by the film-forming sequence of the above-described Modification 7, that is, a film-forming sequence of supplying a HCDS gas to the wafers by using simultaneously the first and second nozzles and supplying a NH3gas to the wafers from the third nozzle.

As Comparative Example 1, the substrate processing apparatus used in Example 1 is used to form a SiN film on wafers by the film-forming sequence of performing only the first film-forming step a plurality of times, among the film-forming sequence shown inFIG.4, that is, a film-forming sequence of supplying a HCDS gas to the wafers by using only the first nozzle and supplying a NH3gas to the wafers from the third nozzle.

As Comparative Example 2, the substrate processing apparatus used in Example 1 is used to form a SiN film on wafers by the film-forming sequence of performing only the second film-forming step a plurality of times, among the film-forming sequence shown inFIG.4, that is, a film-forming sequence of supplying a HCDS gas to the wafers by using only the second nozzle and supplying a NH3gas to the wafers from the third nozzle.

Then, an inter-wafer film thickness distribution of the SiN film formed on the wafer is measured for each of Examples 1 and 2 and Comparative Examples 1 and 2.FIGS.10A and10Bshow measurement results of the inter-wafer film thickness distribution of the SiN film formed on the wafers. Horizontal axes inFIGS.10A and10Beach represent wafer accommodation positions (Top, Center, and Bottom) in the wafer arrangement region. Vertical axes inFIGS.10A and10Beach represent the film thickness (a.u.) of the SiN film formed on the wafers. Marks ▴, ♦ and ▪ inFIG.10Aindicate Example 1, Comparative Example 1, and Comparative Example 2 in this order. Further, marks ▴, ♦ and ▪ inFIG.10Bindicate Example 2, Comparative Example 1, and Comparative Example 2 in this order.

As shown inFIGS.10A and10B, in Comparative Example 1 in which the HCDS gas is supplied to the wafers by using only the first nozzle, the inter-wafer film thickness distribution of the SiN film formed on the wafers is a distribution in which the film thickness gradually increases from the Bottom side toward the Top side of the wafer arrangement region. Further, in Comparative Example 2 in which the HCDS gas is supplied to the wafers by using only the second nozzle, the inter-wafer film thickness distribution of the SiN film formed on the wafers is a distribution in which the film thickness gradually decreases from the Bottom side toward the Top side of the wafer arrangement region.

In contrast, as shown inFIG.10A, in Example 1 in which the HCDS gas is supplied to the wafers by using alternatively the first and second nozzles, the inter-wafer film thickness distribution of the SiN film formed on the wafers is an intermediate distribution between the inter-wafer film thickness distributions in Comparative Examples 1 and 2. Further, as shown inFIG.10B, in Example 2 in which the HCDS gas is supplied to the wafers by using simultaneously the first and second nozzles, the inter-wafer film thickness distribution of the SiN film formed on the wafers is an intermediate distribution between the inter-wafer film thickness distributions in Comparative Examples 1 and 2.

That is, by using the film-forming sequence shown inFIG.4and the film-forming sequence of Modification 7, it was found that the inter-wafer film thickness distribution of the SiN film formed on the wafers can be controlled to improve the inter-wafer film thickness uniformity.

According to the present disclosure in some embodiments, it is possible to control an inter-substrate film thickness distribution of films formed on substrates arranged in a process chamber.