Substrate processing apparatus

There is provided a technique capable of improving a uniformity of a substrate processing on a substrate surface. According to one aspect thereof, there is provided a substrate processing apparatus including: a substrate processing room; a plasma generation room; a gas supplier supplying a gas into the plasma generation room; a first coil surrounding the plasma generation room and to which an electric power is supplied; and a second coil surrounding the plasma generation room and to which an electric power is supplied. An axial direction of the second coil is equal to that of the first coil, a winding diameter of the second coil is different from that of the first coil, and a peak of a voltage distribution generated by supplying the electric power to the second coil does not overlap with a peak of a voltage distribution generated by the first coil.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority under 35 U.S.C. § 119(a)-(d) to Application No. JP 2021-178348 filed on Oct. 29, 2021, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a substrate processing apparatus.

BACKGROUND

According to some related arts, a substrate processing apparatus capable of performing a substrate processing by exciting a process gas into a plasma state by supplying a an electric power to two coils may be used.

For example, in the substrate processing apparatus described above, the two coils of the same diameter are arranged coaxially. Therefore, a plasma density may be biased in a direction parallel to a surface of the substrate, and a uniformity of the substrate processing on the surface of the substrate may decrease.

SUMMARY

According to the present disclosure, there is provided a technique capable of improving a uniformity of a substrate processing on a surface of a substrate.

According to one aspect of the technique of the present disclosure, there is provided a substrate processing apparatus including: a substrate processing room in which a substrate is processed; a plasma generation room in communication with the substrate processing room; a gas supplier capable of supplying a gas into the plasma generation room; a first coil provided to surround the plasma generation room and to which an electric power is supplied; and a second coil provided to surround the plasma generation room and to which an electric power is supplied, wherein the second coil is configured such that an axial direction of the second coil is equal to that of the first coil, a winding diameter of the second coil is set to be different from a winding diameter of the first coil, and a peak of a voltage distribution generated by supplying the electric power to the second coil does not overlap with a peak of a voltage distribution generated by the first coil.

DETAILED DESCRIPTION

Embodiments

Hereinafter, one or more embodiments (also simply referred to as “embodiments”) according to the technique of the present disclosure will be described with reference to the drawings. The drawings used in the following descriptions are all schematic. For example, a relationship between dimensions of each component and a ratio of each component shown in the drawing may not always match the actual ones. Further, even between the drawings, the relationship between the dimensions of each component and the ratio of each component may not always match.

(1) Configuration of Substrate Processing Apparatus

Hereinafter, a substrate processing apparatus100according to the embodiments of the present disclosure will be described with reference toFIGS.1through10. For example, the substrate processing apparatus100according to the present embodiments is configured to mainly perform a substrate processing such as an oxidation process onto a film formed on a surface of a substrate or onto a base of the substrate.

Process Chamber

The substrate processing apparatus100includes a process furnace202in which a wafer200serving as the substrate is processed by a plasma. The process furnace202includes a process vessel203, and a process chamber201is defined by the process vessel203. The process vessel203includes a dome-shaped upper vessel210serving as a first vessel and a bowl-shaped lower vessel211serving as a second vessel. By covering the lower vessel211with the upper vessel210, the process chamber201is defined. The upper vessel210constitutes a plasma vessel in which a plasma generation space201A is provided. In the plasma generation space201A, a process gas is excited into a plasma state.

In addition, a gate valve244is provided on a lower side wall of the lower vessel211. While the gate valve244is open, the wafer200can be transferred (loaded) into the process chamber201through a substrate loading/unloading port245using a substrate transfer device (not shown) or be transferred (unloaded) out of the process chamber201through the substrate loading/unloading port245using the substrate transfer device. While the gate valve244is closed, the gate valve244maintains the process chamber201airtight.

The process chamber201includes the plasma generation space201A and a substrate processing space201B. The plasma generation space201A is a space in which a first resonance coil212and a second resonance coil214, which are coils serving as electrodes, are provided around the space, and the plasma is generated in the plasma generation space201A. More specifically, the plasma generation space201A refers to a space in the process chamber201above a lower end of the first resonance coil212and below an upper end of the first resonance coil212. The substrate processing space201B is a space that communicates with the plasma generation space201A and in which the wafer200is processed. More specifically, the substrate processing space201B refers to a space in which the wafer200is processed by using the plasma, for example, a space below the lower end of the first resonance coil212. According to the present embodiments, a diameter of the plasma generation space201A in a horizontal direction is the same as a diameter of the substrate processing space201B in the horizontal direction. A configuration constituting the plasma generation space201A may also be referred to as a “plasma generation room”, and a configuration constituting the substrate processing space201B may also be referred to as a “substrate processing room”. Further, the plasma generation space201A may also be referred to as a “plasma generation region” in the process chamber201, and the substrate processing space201B may also be referred to as a “substrate processing region” in the process chamber201.

A susceptor (which is a substrate mounting table)217serving as a substrate support on which the wafer200is placed is provided at a center of a bottom portion of the process chamber201. The susceptor217is provided in the process chamber201and below the first resonance coil212.

A heater217B serving as a heating structure is integrally embedded in the susceptor217. When an electric power is supplied to the heater217B, the heater217B is configured to heat the wafer200.

The susceptor217is electrically insulated from the lower vessel211. An impedance adjusting electrode217C is provided in the susceptor217in order to further improve a uniformity of a density of the plasma generated on the wafer200placed on the susceptor217. The impedance adjustment electrode217C is grounded via a variable impedance regulator275serving as an impedance adjusting structure.

A susceptor elevator268including a driving structure capable of elevating and lowering the susceptor217is provided at the susceptor217. Through-holes217A are provided at the susceptor217, and wafer lift pins266are provided on a bottom surface of the lower vessel211. When the susceptor217is lowered by the susceptor elevator268, the wafer lift pins266are configured to penetrate the through-holes217A without contacting the susceptor217.

Gas Supplier

A gas supply head236is provided above the process chamber201, that is, on an upper portion of the upper vessel210. The gas supply head236includes a cap-shaped lid233, a gas inlet port234, a buffer chamber237, an opening238, a shield plate240and a gas outlet port239. The gas supply head236is configured such that a gas such as a reactive gas is supplied into the process chamber201through the gas supply head236. The buffer chamber237functions as a dispersion space in which the gas such as the reactive gas introduced (supplied) through the gas inlet port234is dispersed.

A downstream end of an oxygen-containing gas supply pipe232A through which an oxygen-containing gas is supplied, a downstream end of a hydrogen-containing gas supply pipe232B through which a hydrogen-containing gas is supplied and a downstream end of an inert gas supply pipe232C through which an inert gas is supplied are connected to the gas inlet port234through a confluence pipe232. Hereinafter, the oxygen-containing gas supply pipe232A may also be simply referred to as a “gas supply pipe232A”, the hydrogen-containing gas supply pipe232B may also be simply referred to as a “gas supply pipe232B”, and the inert gas supply pipe232C may also be simply referred to as a “gas supply pipe232C”. An oxygen-containing gas supply source250A, a mass flow controller (MFC)252A serving as a flow rate controller and a valve253A serving as an opening/closing valve are sequentially provided at the oxygen-containing gas supply pipe232A in this order from an upstream side to a downstream side of the oxygen-containing gas supply pipe232A in a gas flow direction. A hydrogen-containing gas supply source250B, an MFC252B and a valve253B are sequentially provided at the hydrogen-containing gas supply pipe232B in this order from an upstream side to a downstream side of the hydrogen-containing gas supply pipe232B in the gas flow direction. An inert gas supply source250C, an MFC252C and a valve253C are sequentially provided at the inert gas supply pipe232C in this order from an upstream side to a downstream side of the inert gas supply pipe232C in the gas flow direction. A valve243A is provided on a downstream side of the confluence pipe232where the oxygen-containing gas supply pipe232A, the hydrogen-containing gas supply pipe232B and the inert gas supply pipe232C join. The confluence pipe232is connected to an upstream end the gas inlet port234. It is possible to supply the process gas such as the oxygen-containing gas, the hydrogen-containing gas and the inert gas into the process chamber201via the oxygen-containing gas supply pipe232A, the hydrogen-containing gas supply pipe232B and the inert gas supply pipe232C by opening and closing the valves253A,253B,253C and243A while adjusting flow rates of the respective gases by the MFCs252A,252B and252C.

For example, an oxygen-containing gas supplier (which is an oxygen-containing gas supply structure or an oxygen-containing gas supply system) according to the present embodiments is constituted mainly by the oxygen-containing gas supply pipe232A, the MFC252A, the valve253A and the valve243A. In addition, a hydrogen-containing gas supplier (which is a hydrogen-containing gas supply structure or a hydrogen-containing gas supply system) according to the present embodiments is constituted mainly by the hydrogen-containing gas supply pipe232B, the MFC252B, the valve253B and the valve243A. In addition, an inert gas supplier (which is an inert gas supply structure or an inert gas supply system) according to the present embodiments is constituted mainly by the inert gas supply pipe232C, the MFC252C, the valve253C and the valve243A.

A gas supplier (which is a gas supply structure or a gas supply system) according to the present embodiments is constituted mainly by the oxygen-containing gas supply pipe232A, the hydrogen-containing gas supply pipe232B, the inert gas supply pipe232C, the MFCs252A,252B and252C, the valves253A,253B and253C and the valve243A. The gas supplier (gas supply system) is configured such that the process gas can be supplied into the process vessel203. For example, one of the oxygen-containing gas supplier, the hydrogen-containing gas supplier and the inert gas supplier or a combination thereof may also be referred to as the “gas supplier”.

A gas exhaust port235is provided on a side wall of the lower vessel211. An inner atmosphere of the process chamber201(for example, the reactive gas in the process chamber201) is exhausted through the gas exhaust port235. An upstream end of a gas exhaust pipe231is connected to the gas exhaust port235. An APC (Automatic Pressure Controller) valve242serving as a pressure regulator (pressure adjusting structure), a valve243B serving as an opening/closing valve and a vacuum pump246serving as a vacuum exhaust apparatus are sequentially provided at the gas exhaust pipe231in this order from an upstream side to a downstream side of the gas exhaust pipe231in the gas flow direction. An exhauster (which is an exhaust structure or an exhaust system) according to the present embodiments is constituted mainly by the gas exhaust port235, the gas exhaust pipe231, the APC valve242and the valve243B. The exhauster may further include the vacuum pump246.

Plasma Generator

The first resonance coil212and the second resonance coil214are respectively arranged on an outer side of the process vessel203so as to surround an outer periphery of the process vessel203. Specifically, the first resonance coil212and the second resonance coil214are respectively arranged so as to surround an outer periphery of a portion (region) corresponding to the plasma generation space201A (that is, an outer periphery of the plasma generation room) in the process vessel203. The first resonance coil212is provided by winding a conductor212A of a line shape or a string shape a plurality of times in a spiral shape in the same direction. Both ends (that is, an upper end212B and a lower end212C shown inFIG.8) of the first resonance coil212are grounded, and a portion of the first resonance coil212between the upper end212B and the lower end212C surrounds the outer periphery of the process vessel203. Specifically, the first resonance coil212surrounds an outer peripheral portion of the process chamber201, that is, an outer periphery of a side wall of the upper vessel210. In other words, the process vessel203is inserted into an inner side of the first resonance coil212. In addition, according to the present embodiments, the first resonance coil212and the outer periphery (outer surface) of the process vessel203are provided close to each other such that a high frequency electromagnetic field generated by the first resonance coil212can excite the process gas in the process vessel203into the plasma state by the plasma. Further, a winding diameter of the first resonance coil212according to the present embodiments is constant and the same at positions on the first resonance coil212. An RF power is supplied to the first resonance coil212.

The second resonance coil214is provided by winding a conductor214A of a line shape or a string shape a plurality of times in a spiral shape in the same direction. Both ends (that is, an upper end214B and a lower end214C shown inFIG.8) of the second resonance coil214are grounded, and a portion of the second resonance coil214between the upper end214B and the lower end214C surrounds the outer periphery of the process vessel203. Specifically, the second resonance coil214surrounds the outer peripheral portion of the process chamber201, that is, the outer periphery of the side wall of the upper vessel210. In other words, the process vessel203is inserted into an inner side of the second resonance coil214. In addition, according to the present embodiments, similar to the first resonance coil212, the second resonance coil214and the outer periphery (outer surface) of the process vessel203are provided close to each other such that a high frequency electromagnetic field generated by the second resonance coil214can excite the process gas in the process vessel203into the plasma state by the plasma. Further, a winding diameter of the second resonance coil214according to the present embodiments is constant and the same at positions on the second resonance coil214. Further, according to the present embodiments, the winding diameter D1of the first resonance coil212and the winding diameter D2of the second resonance coil214are different. Specifically, the winding diameter D2of the second resonance coil214is set to be greater than the winding diameter D1of the first resonance coil212. According to the present embodiments, for example, the winding diameter D2is preferably set within a range from 101% to 125%, preferably from 105% to 120% of the winding diameter D1.

As shown inFIG.8, an axial direction of the first resonance coil212(that is, a direction along a spiral axis of the first resonance coil212) and an axial direction of the second resonance coil214(that is, a direction along a spiral axis of the second resonance coil214) are the same direction. That is, the axial direction of the second resonance coil214is equal to the axial direction of the first resonance coil212. More specifically, according to the present embodiments, the spiral axis of the first resonance coil212and the spiral axis of the second resonance coil214are coaxial. In addition, according to the present embodiments, the axial direction of each resonance coil is the same direction as an up-and-down direction of the substrate processing apparatus100, that is, the same direction as a vertical direction. InFIG.7, an upper direction of the substrate processing apparatus100is indicated by an arrow “U”, and a radial direction of the process vessel203is indicated by an arrow “R”. According to the present embodiments, the radial direction of the process vessel203is the same direction as a horizontal direction of the substrate processing apparatus100, and is also the same direction as a direction perpendicular to the spiral axis of each resonance coil. Further, the conductor212A constituting the first resonance coil212and the conductor214A constituting the second resonance coil214are alternately arranged in the vertical direction (that is, the axial direction of each resonance coil). According to the present embodiments, for example, when the first resonance coil212and the second resonance coil214are viewed from the vertical direction, an outer peripheral portion of the first resonance coil212overlaps with an inner peripheral portion of the second resonance coil214. By providing the first resonance coil212and the second resonance coil214such that a part of the first resonance coil212overlaps with a part of the second resonance coil214when viewed from the vertical direction, it is possible to suppress an increase in a size of a vessel (not shown) covering each resonance coil in the radial direction. On the other hand, for example, when the first resonance coil212and the second resonance coil214do not overlap with each other when viewed from the vertical direction, that is, when there is a gap between the first resonance coil212and the second resonance coil214, by securing a distance between the first resonance coil212and the second resonance coil214, it is possible to suppress a generation of an arc discharge. Further, the distance between the first resonance coil212and the second resonance coil214may be set to a distance in advance such that no arc discharge is generated therebetween. In addition, the RF power is supplied to the second resonance coil214.

As shown inFIG.8, an axial length (that is, a length along the spiral axis) of a coil portion of the first resonance coil212is set to be longer than an axial length (that is, a length along the spiral axis) of a coil portion of the second resonance coil214. Therefore, the conductor212A of the first resonance coil212and the conductor214A of the second resonance coil214are alternately arranged in the vertical direction (that is, the axial direction of each resonance coil) from an upper portion to the vicinity of a central portion of the first resonance coil212in the vertical direction. According to the present embodiments, a region in which the first resonance coil212and the second resonance coil214are arranged is provided on the outer periphery of the process vessel203. Specifically, the region in which the first resonance coil212and the second resonance coil214are arranged may also be referred to as a “first arrangement region”, and is indicated by a reference character “FA” (seeFIG.8). In addition, a region in which the first resonance coil212is arranged and the second resonance coil214is not arranged may be referred to as a “second arrangement region”, and is indicated by a reference character “SA” (seeFIG.8). The second arrangement region SA is provided closer to the susceptor217than the first arrangement region FA in the up-and-down direction of the substrate processing apparatus100(that is, the vertical direction).

An RF (Radio Frequency) sensor272, an RF power supply273and a matcher (which is a matching structure)274configured to perform an impedance matching or an output frequency matching for the RF power supply273are connected to the first resonance coil212.

The RF power supply273is configured to supply the RF power to the first resonance coil212. The RF sensor272is provided at an output side of the RF power supply273. The RF sensor272is configured to monitor information of the traveling wave or reflected wave of the RF power supplied from the RF power supply273. The information of the reflected wave monitored by the RF sensor272is input to the matcher274, and the matcher274is configured to match (or adjust) an impedance or a frequency of the RF power output from the RF power supply273so as to minimize the reflected wave based on the information of the reflected wave input from the RF sensor272.

The RF power supply273includes a power supply controller (which is a control circuit) (not shown) and an amplifier (which is an output circuit) (not shown). The power supply controller includes a high frequency oscillation circuit (not shown) and a preamplifier (not shown) in order to adjust an oscillation frequency and an output. The amplifier amplifies the output to a predetermined output level. The power supply controller controls the amplifier based on output conditions relating to the frequency and the power, which are set in advance through an operation panel (not shown), and the amplifier supplies a constant RF power to the first resonance coil212via a transmission line. The RF sensor272and the matcher274are collectively referred to as a “RF power supplier271” which is a RF power supply structure or a RF power supply system. The RF power supplier271may further include the RF power supply273.

An RF (Radio Frequency) sensor282, an RF power supply283and a matcher (which is a matching structure)284configured to perform an impedance matching or an output frequency matching for the RF power supply283are connected to the second resonance coil214.

The RF power supply283is configured to supply the RF power to the second resonance coil214. The RF sensor282is provided at an output side of the RF power supply283. The RF sensor282is configured to monitor information of the traveling wave or reflected wave of the RF power supplied from the RF power supply283. The information of the reflected wave monitored by the RF sensor282is input to the matcher284, and the matcher284is configured to match (or adjust) an impedance or a frequency of the RF power output from the RF power supply283so as to minimize the reflected wave based on the information of the reflected wave input from the RF sensor282.

The RF power supply283includes a power supply controller (which is a control circuit) (not shown) and an amplifier (which is an output circuit) (not shown). The power supply controller includes a high frequency oscillation circuit (not shown) and a preamplifier (not shown) in order to adjust an oscillation frequency and an output. The amplifier amplifies the output to a predetermined output level. The power supply controller controls the amplifier based on output conditions relating to the frequency and the power, which are set in advance through the operation panel (not shown), and the amplifier supplies a constant RF power to the second resonance coil214via a transmission line. The RF sensor282and the matcher284are collectively referred to as a “RF power supplier281” which is a RF power supply structure or an RF power supply system. The RF power supplier281may further include the RF power supply283.

The winding diameter, a winding pitch and the number of winding turns of the first resonance coil212are set such that the first resonance coil212resonates at a constant wavelength to form a standing wave of a predetermined wavelength. That is, an electrical length of the first resonance coil212is set to an integral multiple (n times, where n is equal to or greater than 1) of a wavelength of a predetermined frequency of the RF power supplied from the RF power supply273.

In addition, the winding diameter, a winding pitch and the number of winding turns of the second resonance coil214are set such that the second resonance coil214resonates at a constant wavelength to form a standing wave of a predetermined wavelength. That is, an electrical length of the second resonance coil214is set to an integral multiple (n times, where n is equal to or greater than 1) of a wavelength of a predetermined frequency of the RF power supplied from the RF power supply283.

Specifically, considering conditions such as the power to be applied, a strength of a magnetic field to be generated and a shape of the substrate processing apparatus100to be applied, the first resonance coil212is set such that, for example, the magnetic field of about 0.01 Gauss to about 10 Gauss can be generated by the RF power whose frequency is from 800 kHz to 50 MHz and whose power is from 0.1 kW to 5 kW. For example, the first resonance coil212whose effective cross-section is from 50 mm2 to 300 mm2 and whose diameter is from 200 mm to 500 mm is wound, for example, twice to 60 times around an outer circumferential side of the process chamber201defining the plasma generation space201A. Similarly, considering conditions such as the power to be applied, a strength of a magnetic field to be generated and a shape of the substrate processing apparatus100to be applied, the second resonance coil214is set such that, for example, the magnetic field of about 0.01 Gauss to about 10 Gauss can be generated by the RF power whose frequency is from 800 kHz to 50 MHz and whose power is from 0.1 kW to 5 kW. For example, the second resonance coil214whose effective cross-section is from 50 mm2 to 300 mm2 and whose diameter is from 200 mm to 500 mm is wound, for example, twice to 60 times around the outer circumferential side of the process chamber201defining the plasma generation space201A.

As shown inFIG.7, the first resonance coil212and the second resonance coil214are arranged such that a position of an anti-node of the standing wave by the first resonance coil212and a position of an anti-node of the standing wave by the second resonance coil214do not overlap with each other. In other words, a peak of a voltage distribution of the first resonance coil212and a peak of a voltage distribution of the second resonance coil214do not overlap with each other. Further, the distance between the first resonance coil212and the second resonance coil214is set to the distance at which no arc discharge is generated between the conductor212A of the first resonance coil212and the conductor214A of the second resonance coil214.

For example, a copper pipe, a copper thin plate, an aluminum pipe, an aluminum thin plate and a material obtained by depositing copper or aluminum on a polymer belt may be used as a material constituting each of the first resonance coil212and the second resonance coil214. Each of the first resonance coil212and the second resonance coil214is supported by a plurality of supports (not shown) of a plate shape and made of an insulating material, which are provided on an upper end surface of a base plate248so as to extend vertically.

The both ends of the first resonance coil212are electrically grounded. One end of the first resonance coil212(for example, the upper end212B shown inFIGS.2,4and8) is grounded via a movable tap300in order to fine-tune the electrical length of the first resonance coil212when the substrate processing apparatus100is newly installed or process conditions of the substrate processing apparatus100are changed, and the other end of the first resonance coil212(for example, the lower end212C shown inFIGS.1through4,7and8) is grounded as a fixed ground. In addition, in order to fine-tune impedance (or the electrical length) of the first resonance coil212when the substrate processing apparatus100is newly installed or the process conditions of the substrate processing apparatus100are changed, a power feeder (not shown) is constituted by a movable tap305between the grounded ends of the first resonance coil212. Further, a position of the movable tap305may be adjusted in order for the resonance characteristics of the first resonance coil212to become approximately the same as those of the RF power supply273. Since the first resonance coil212includes a variable ground structure (that is, the movable tap300) and a variable power supply feeding structure (that is, the power feeder constituted by the movable tap305), it is possible to easily adjust a resonance frequency and a load impedance of the process chamber201. The upper end212B of the first resonance coil212according to the present embodiments is an example of a first ground connection portion according to the technique of the present disclosure. Further, the lower end212C of the first resonance coil212according to the present embodiments is an example of a second ground connection portion according to the technique of the present disclosure. When the vicinity of the upper end212B of the first resonance coil212is grounded, a location in the vicinity of the upper end212B becomes a grounding point and serves as the first ground connection portion. In addition, when the vicinity of the lower end212C of the first resonance coil212is grounded, a location in the vicinity of the lower end212C becomes a grounding point and serves as the second ground connection portion.

The both ends of the second resonance coil214are electrically grounded. One end of the second resonance coil214(for example, the upper end214B shown inFIGS.6and8) is grounded via a movable tap302in order to fine-tune the electrical length of the second resonance coil214when the substrate processing apparatus100is newly installed or the process conditions of the substrate processing apparatus100are changed, and the other end of the second resonance coil214(for example, the lower end214C shown inFIGS.1,6,7and8) is grounded as a fixed ground. In addition, in order to fine-tune the impedance (or the electrical length) of the second resonance coil214when the substrate processing apparatus100is newly installed or the process conditions of the substrate processing apparatus100are changed, a power feeder (not shown) is constituted by a movable tap306between the grounded ends of the second resonance coil214. Further, a position of the movable tap306may be adjusted in order for the resonance characteristics of the second resonance coil214to become approximately the same as those of the RF power supply283. Since the second resonance coil214includes a variable ground structure (that is, the movable tap302) and a variable power supply feeding structure (that is, the power feeder constituted by the movable tap306), it is possible to easily adjust the resonance frequency and the load impedance of the process chamber201. The upper end214B of the second resonance coil214according to the present embodiments is an example of a third ground connection portion according to the technique of the present disclosure. Further, the lower end214C of the second resonance coil214according to the present embodiments is an example of a fourth ground connection portion according to the technique of the present disclosure. When the vicinity of the upper end214B of the second resonance coil214is grounded, a location in the vicinity of the upper end214B becomes a grounding point and serves as the third ground connection portion. In addition, when the vicinity of the lower end214C of the second resonance coil214is grounded, a location in the vicinity of the lower end214C becomes a grounding point and serves as the fourth ground connection portion.

A waveform adjustment circuit308constituted by a resonance coil (not shown) and a shield (not shown) is inserted into one end (or the other end or the both ends) of the first resonance coil212so that the phase current and the opposite phase current flow symmetrically with respect to an electrical midpoint of the first resonance coil212. The waveform adjustment circuit308is configured to be open by setting the first resonance coil212to an electrically disconnected state or an electrically equivalent state. In addition, an end portion of the first resonance coil212may be non-grounded by a choke series resistor, or may be DC-connected to a fixed reference potential.

In addition, a waveform adjustment circuit309constituted by a resonance coil (not shown) and a shield (not shown) is inserted into one end (or the other end or the both ends) of the second resonance coil214so that the phase current and the opposite phase current flow symmetrically with respect to an electrical midpoint of the second resonance coil214. The waveform adjustment circuit309is configured to be open by setting the second resonance coil214to an electrically disconnected state or an electrically equivalent state. In addition, an end portion of the second resonance coil214may be non-grounded by a choke series resistor, or may be DC-connected to a fixed reference potential.

For example, the waveform adjustment circuit308or309may be arranged on at least one of the first resonance coil212or the second resonance coil214. According to the present embodiments, as the waveform adjustment circuit308or309, for example, a variable capacitor may be used, or a wire (coil) made of a conductor may be used.

A shield plate223is provided to shield an electric field outside of the first resonance coil212and/or the second resonance coil214and to form a capacitive component (also referred to as a “C component”) of the first resonance coil212or the second resonance coil214appropriate for constructing a resonance circuit between the shield plate223and the first resonance coil212or between the shield plate223and the second resonance coil214. In general, the shield plate223is made of a conductive material such as an aluminum alloy, and is of a cylindrical shape. The shield plate223is disposed, for example, about 5 mm to 150 mm apart from an outer periphery of each of the first resonance coil212and the second resonance coil214.

A first plasma generator according to the present embodiments is constituted mainly by the first resonance coil212, the RF sensor272and the matcher274. In addition, the first plasma generator may further include the RF power supply273. Further, a second plasma generator according to the present embodiments is constituted mainly by the second resonance coil214, the RF sensor282and the matcher284. In addition, the second plasma generator may further include the power supply283. The first plasma generator and the second plasma generator may be collectively referred to as a “plasma generator”.

Hereinafter, a principle of generating the plasma in the substrate processing apparatus100of the present embodiments and the properties of the generated plasma will be described. Since the principles of generating the plasma by each of the first resonance coil212and the second resonance coil214are the same, the principle of generating the plasma by the first resonance coil212will be described hereafter as an example (seeFIGS.3through5).

A plasma generation circuit constituted by the first resonance coil212is configured as an RLC parallel resonance circuit. When the wavelength of the RF power supplied from the RF power supply273and the electrical length of the first resonance coil212are the same, the resonance condition of the first resonance coil212is that a reactance component generated by a capacitance component or an inductive component of the first resonance coil212is canceled out to become a pure resistance. However, when the plasma is generated in the plasma generation circuit described above, an actual resonance frequency may fluctuate slightly depending on conditions such as a variation (change) in a capacitive coupling between a voltage portion of the first resonance coil212and the plasma, a variation in an inductive coupling between the plasma generation space201A and the plasma and an excitation state of the plasma.

Therefore, in the substrate processing apparatus100according to the present embodiments, in order to compensate for a resonance shift in the first resonance coil212when the plasma is generated by adjusting the power supplied from the RF power supply273, the RF sensor272is configured to detect the power of the reflected wave from the first resonance coil212when the plasma is generated, and the matcher274is configured to correct the output of the RF power supply273based on the detected power of the reflected wave.

Specifically, the matcher274is configured to increase or decrease the impedance or the output frequency of the RF power supply273such that the power of the reflected wave is minimized based on the power of the reflected wave from the first resonance coil212detected by the RF sensor272when the plasma is generated. In case the impedance is controlled by the matcher274, the matcher274is constituted by a variable capacitor control circuit (not shown) capable of correcting a preset impedance. In case the output frequency of the RF power supply273is controlled by the matcher274, the matcher274is constituted by a frequency control circuit (not shown) capable of correcting a preset oscillation frequency of the RF power supply273. For example, the RF power supply273and the matcher274may be provided integrally as a single body.

According to the configuration related to the first resonance coil212according to the present embodiments, the RF power whose frequency is equal to the actual resonance frequency of the first resonance coil212combined with the plasma is supplied to the first resonance coil212(or the RF power is supplied to match an actual impedance of the first resonance coil212combined with the plasma). Therefore, the standing wave in which the phase voltage thereof and the opposite phase voltage thereof are always canceled out by each other is generated in the first resonance coil212(seeFIG.3). For example, when the wavelength of the RF power and the electrical length of the first resonance coil212are the same, the highest phase current is generated at an electrical midpoint of the first resonance coil212(node with zero voltage). Specifically, when the RF power is supplied from the RF power supply273to the first resonance coil212, for example, a current standing wave and a voltage standing wave whose wavelengths are equal to the wavelength of the RF power supplied from the RF power supply273are generated between both ends of a line of the first resonance coil212. Among waveforms on a right portion ofFIG.3, a broken line illustrates the current and a solid line illustrates the voltage. As shown by the waveform on the right portion ofFIG.3, an amplitude of the current standing wave is maximized at the both ends of the first resonance coil212and a midpoint (that is, the electrical midpoint) of the first resonance coil212. Therefore, a donut-shaped induction plasma (which is an inductively coupled plasma (ICP))310of an extremely low electric potential is generated in the vicinity of the electrical midpoint of the first resonance coil212. The donut-shaped ICP310is hardly capacitively coupled with walls of the process chamber201or the susceptor217. Specifically, a high frequency magnetic field is generated in the vicinity of the electrical midpoint of the first resonance coil212where the amplitude of the current standing wave is maximized, and a plasma discharge of the process gas supplied into the plasma generation space201A in the upper vessel210is generated by a high frequency electromagnetic field induced by the high frequency magnetic field. The plasma of the process gas is generated in the vicinity of the electrical midpoint of the first resonance coil212by exciting the process gas discharged by the high frequency electromagnetic field. Hereinafter, the plasma of the process gas generated by the high frequency electromagnetic field generated in the vicinity of a location (region) where the amplitude of the current is great as described above may also be referred to as the “ICP”. As shown inFIG.4, the ICP is generated in a donut shape in a region in the vicinity of the electrical midpoint of the first resonance coil212in a space along an inner wall surface of the upper vessel210. Thereby, the ICP whose plasma density is uniform in a direction parallel to a surface of the wafer200can be generated. Similarly, the induction plasma is also generated at the both axial ends of the first resonance coil212according to the same principle.

Subsequently, an internal state of the process furnace202when the plasma is generated using the first resonance coil212and the second resonance coil214will be described.

In the substrate processing apparatus100according to the present embodiments shown inFIG.8, the first resonance coil212and the second resonance coil214are respectively provided around the plasma generation space201A, similar to a case where the first resonance coil212alone is provided as shown inFIG.4. For example, when the RF power is supplied to the first resonance coil212while the process gas is supplied to the plasma generation space201A, the voltage and the current are generated as shown on a right portion ofFIG.7by the principle described above, and the ICP310is generated in the plasma generation space201A as shown inFIG.8.

Similarly, when the RF power is supplied to the second resonance coil214while the process gas is supplied to the plasma generation space201A, the voltage and the current are generated as shown on a left portion ofFIG.7by the principle described above, and an ICP312is generated in the plasma generation space201A as shown inFIG.8.

By using a plurality of resonance coils (for example, the first resonance coil212and the second resonance coil214), it is possible to generate a large amount of the plasma as compared with a case where a single resonance coil (for example, the first resonance coil212alone) is used to generate the plasma. That is, it is possible to generate a large amount of radical components in the plasma.

According to the present embodiments, the winding diameter D2of the second resonance coil214is set to be different from the winding diameter D1of the first resonance coil212. Therefore, as shown inFIG.7, the peak of the voltage distribution of the first resonance coil212and the peak of the voltage distribution of the second resonance coil214are displaced with each other in the radial direction. That is, the peak of the voltage distribution of the first resonance coil212and the peak of the voltage distribution of the second resonance coil214do not overlap with each other. By making the peaks of the voltage distributions of the two resonance coils (that is, the first resonance coil212and the second resonance coil214) to be apart from each other as described above, it is possible to uniformize a density of the highly concentrated induction plasma along the radial direction (seeFIG.9). Thereby, it is possible to realize a uniformity of the density of induction plasma on a surface of the substrate (that is, on the surface of the wafer200).

Further, the second resonance coil214according to the present embodiments is configured such that, in the direction (horizontal direction) perpendicular to the axial direction, the peak of the voltage distribution thereof does not overlap with the peak of the voltage distribution of the first resonance coil212. By making the peaks of the voltage distributions of the two resonance coils in the horizontal direction to be apart from each other as described above, it is possible to uniformize the density of the plasma. For example, as shown inFIG.9, by separately forming the ICPs (that is, the ICP310and the ICP312) using the two resonance coils, it is possible to increase an amount of the plasma in the radial direction.

Further, the second resonance coil214according to the present embodiments is configured such that, in the axial direction (vertical direction), the peak of the voltage distribution thereof does not overlap with the peak of the voltage distribution of the first resonance coil212. By making the peaks of the voltage distributions of the two resonance coils in the vertical direction to be apart from each other as described above, it is possible to supplement a state of one induction plasma by the other induction plasma. Therefore, it is possible to extend a lifetime of the entirety of the induction plasma.

Further, according to the present embodiments, the first arrangement region FA and the second arrangement region SA are provided on the outer periphery of the process vessel203. In addition, the first resonance coil212alone is continuously arranged in the second arrangement region SA. Therefore, it is possible to adjust a physical length of a coil length with respect to the plasma generation space201A. Thereby, it is possible to secure a flexibility in the design.

Further, according to the present embodiments, the winding diameter D1of the first resonance coil212is set to be smaller than the winding diameter D2of the second resonance coil214. It is possible to form the peak of the voltage distribution using the first resonance coil212with the winding diameter D1smaller than the winding diameter D2of the second resonance coil214. Thereby, it is possible to supply the induction plasma whose density is high to a central region of the substrate (that is, the wafer200).

Further, the second arrangement region SA according to the present embodiments is provided closer to the susceptor217on which the wafer200is placed in the process vessel203than the first arrangement region FA in the axial direction (vertical direction). According to the present embodiments, for example, by reducing the winding diameter of the resonance coil provided closer to the susceptor217(that is, by reducing the winding diameter D1of the first resonance coil212), it is possible to easily supply the plasma to the central region of the wafer200directly below the resonance coil provided closer to the susceptor217.

Further, the process vessel203according to the present embodiments is provided with the exhauster capable of exhausting the process gas from the outer periphery of the susceptor217. As a result, it is possible to diffuse a flow of the induction plasma supplied to the central region of the wafer200toward the outer periphery of the susceptor217. That is, it is possible to diffuse the plasma whose density is high supplied to the central region of the wafer200in an outer peripheral direction, and therefore, it is possible to uniformize a processing of the wafer200on the surface of the wafer200.

Further, according to the present embodiments, in the first arrangement region FA, the conductor212A of the first resonance coil212and the conductor214A of the second resonance coil214are separated from each other at the distance such that no arc discharge is generated therebetween. Further, in the second arrangement region SA, the conductor212A of the first resonance coil212is provided such that no arc discharge is generated between portions of the conductor212A wounded the plurality of times with a gap. For example, when a voltage difference between the resonance coils is equal to or greater than a threshold value, the arc discharge may be generated therebetween, and thereby, the electric power may leak. When the electric power leaks, a desired induction plasma cannot be provided. On the other hand, according to the present embodiments, the conductor212A and the conductor214A are separated from each other at the distance such that no arc discharge is generated therebetween. Thereby, it is possible to suppress a leakage of the electric power. As a result, it is possible to provide the desired induction plasma.

Further, the first resonance coil212according to the present embodiments is configured such that the electrical length between the both ends thereof grounded is a multiple of the wavelength of the RF power supplied to the first resonance coil212. By grounding the both ends of the first resonance coil212as described above, it is possible to provide the multiple of the wavelength of the RF power supplied to the first resonance coil212. Thereby, it is possible to provide a sine curve of the voltage shown inFIG.7. As a result, it is possible to easily control the peak of the voltage distribution of the first resonance coil212.

Further, the second resonance coil214according to the present embodiments is configured such that the electrical length between the both ends thereof grounded is a multiple of the wavelength of the RF power supplied to the second resonance coil214. By grounding the both ends of the second resonance coil214as described above, it is possible to provide the multiple of the wavelength of the RF power supplied to the second resonance coil214. Thereby, it is possible to provide a sine curve of the voltage shown inFIG.7. As a result, it is possible to easily control the peak of the voltage distribution of the second resonance coil214.

Further, according to the present embodiments, the waveform adjustment circuits308and309configured to correct the electrical length are connected to the first resonance coil212and the second resonance coil214, respectively, such that the electrical length of the first resonance coil212and the electrical length of the second resonance coil214are equal to each other. When the electrical lengths described above cannot be adjusted by grounding, the electrical lengths can be adjusted by using the waveform adjustment circuits308and309as described above.

Further, according to the present embodiments, a position of the grounded upper end212B of the first resonance coil212in the vertical direction is set to be different from a position of the grounded upper end214B of the second resonance coil214. By setting grounding heights of the upper ends of the resonance coils different from each other as described above, it is possible to more reliably make positions of the peaks of the voltage distributions to be more reliably spaced apart from each other.

Further, according to the present embodiments, a position of the grounded lower end212C of the first resonance coil212in the vertical direction is set to be different from a position of the grounded lower end214C of the second resonance coil214. By setting grounding heights of the lower ends of the resonance coils different from each other as described above, it is possible to more reliably make the positions of the peaks of the voltage distributions to be more reliably spaced apart from each other.

Further, according to the present embodiments, the frequency of the RF power generated from the RF power supply273connected to the first resonance coil212is the same as the frequency of the RF power generated from the RF power supply283connected to the second resonance coil214. When the frequencies of the RF power supply273and the RF power supply283are the same as described above, it is possible to set the wavelengths of the RF power supply273and the RF power supply283to be the same. As a result, it is possible to easily control the positions of the peaks of the voltage distributions.

Further, according to the present embodiments, a controller221described later controls components constituting the substrate processing apparatus100to supply the process gas into the process chamber201while supplying the RF power to the first resonance coil212and the second resonance coil214. Thereby, it is possible to generate two types of the induction plasma in the plasma generation space201A. As a result, it is possible to more reliably uniformize the induction plasma.

Controller

The controller221serving as a control structure is configured to control the components constituting the substrate processing apparatus100. For example, the controller221is configured to control the APC valve242, the valve243B and the vacuum pump246via a signal line “A” shown inFIG.1. For example, the controller221is configured to control the susceptor elevator268via a signal line “B” shown inFIG.1. For example, the controller221is configured to control a heater power regulator276and the variable impedance regulator275via a signal line “C” shown inFIG.1. For example, the controller221is configured to control the gate valve244via a signal line “D” shown inFIG.1. For example, the controller221is configured to control the RF sensor272, the RF power supply273, the matcher274, the RF sensor282, the RF power supply283and the matcher284via a signal line “E” shown inFIG.1. For example, the controller221is configured to control the MFCs252A,252B and252C, the valves253A,253B and253C and the valve243A via a signal line “F” shown inFIG.1.

As shown inFIG.10, the controller221(control structure) is constituted by a computer including a CPU (Central Processing Unit)221A, a RAM (Random Access Memory)221B, a memory221C and an I/O port221D. The RAM221B, the memory221C and the I/O port221D may exchange data with the CPU221A through an internal bus221E. For example, an input/output device225constituted by components such as a touch panel and a display may be connected to the controller221.

For example, the memory221C is configured by a component such as a flash memory and a hard disk drive (HDD). For example, a control program configured to control the operation of the substrate processing apparatus100or a process recipe containing information on the sequences and conditions of the substrate processing described later is readably stored in the memory221C. The process recipe is obtained by combining steps of the substrate processing described later such that the controller221can execute the steps to acquire a predetermined result, and functions as a program. Hereinafter, the process recipe and the control program are collectively or individually referred to as a “program”. Thus, in the present specification, the term “program” may refer to the process recipe alone, may refer to the control program alone, or may refer to both of the process recipe and the control program. The RAM221B functions as a memory area (work area) where a program or data read by the CPU221A is temporarily stored.

The I/O port221D is electrically connected to the components described above such as the MFCs252A through252C, the valves253A through253C, the valves243A and243B, the gate valve244, the APC valve242, the vacuum pump246, the RF sensor272, the RF power supply273, the matcher274, the RF sensor282, the RF power supply283, the matcher284, the susceptor elevator268, the variable impedance regulator275and the heater power regulator276.

The CPU221A is configured to read and execute the control program stored in the memory221C, and to read the process recipe stored in the memory221C in accordance with an instruction such as an operation command inputted via the input/output device225. The CPU221A is configured to control the operation of the substrate processing apparatus100according to the read process recipe. For example, the CPU221A is configured to perform an operation of adjusting an opening degree of the APC valve242, an opening and closing operation of the valve243B and a start and stop of the vacuum pump246via the I/O port221D and the signal line A according to the read process recipe. For example, the CPU221A is configured to perform an elevating and lowering operation of the susceptor elevator268via the signal line B according to the read process recipe. For example, the CPU221A is configured to perform a power supply amount adjusting operation (temperature adjusting operation) on the heater217B by the heater power regulator276and an impedance adjusting operation by the variable impedance regulator275via the signal line C according to the read process recipe. For example, the CPU221A is configured to perform an opening and closing operation of the gate valve244via the signal line D according to the read process recipe. For example, the CPU221A is configured to perform a controlling operation of the RF sensor272, the matcher274, the RF power supply273, the RF sensor282, the matcher284and the RF power supply283via the signal line E according to the read process recipe. For example, the CPU221A is configured to perform flow rate adjusting operations for various gases by the MFCs252A,252B and252C and opening and closing operations of the valves253A,253B,253C and243A via the signal line F according to the read process recipe. The CPU221A may control operations of components of the substrate processing apparatus100other than the components described above.

The controller221may be embodied by installing the above-described program stored in an external memory226into a computer. For example, the external memory226may include a magnetic tape, a magnetic disk such as a flexible disk and a hard disk, an optical disk such as a CD and a DVD, a magneto-optical disk such as an MO and a semiconductor memory such as a USB memory and a memory card. The memory221C or the external memory226may be embodied by a non-transitory computer readable recording medium. Hereafter, the memory221C and the external memory226are collectively or individually referred to as a “recording medium”. In the present specification, the term “recording medium” may refer to the memory221C alone, may refer to the external memory226alone, and may refer to both of the memory221C and the external memory226. Instead of the external memory226, a communication means such as the Internet and a dedicated line may be used for providing the program to the computer.

Subsequently, the substrate processing according to the present embodiments will be described with reference toFIG.11.FIG.11is a flowchart schematically illustrating the substrate processing according to the present embodiments. For example, the substrate processing, which is a part of a manufacturing process of a semiconductor device such as a flash memory, is performed by the substrate processing apparatus100described above. In the following description, the operations of the components constituting the substrate processing apparatus100are controlled by the controller221.

For example, although not shown, a trench is formed in advance on the surface of the wafer200to be processed by the substrate processing according to the present embodiments. In addition, the trench includes a concave-convex portion of a high aspect ratio. According to the present embodiments, for example, the oxidation process serving as a process using the plasma (that is, the substrate processing) is performed to a silicon layer exposed on an inner wall of the trench.

Substrate Loading Step S110

First, the wafer200is transferred (loaded) into the process chamber201. Specifically, the susceptor217is lowered to a position for transferring the wafer200(also referred to as a “transfer position”) by the susceptor elevator268such that the wafer lift pins266pass through the through-holes217A of the susceptor217. As a result, the wafer lift pins266protrude from a surface of the susceptor217by a predetermined height.

Subsequently, the gate valve244is opened, and the wafer200is transferred (loaded) into the process chamber201using a wafer transfer device (not shown) from a vacuum transfer chamber (not shown) provided adjacent to the process chamber201. The wafer200loaded into the process chamber201is placed on and supported in a horizontal orientation by the wafer lift pins266protruding from the surface of the susceptor217. After the wafer200is loaded into the process chamber201and supported by the wafer lift pins266, the wafer transfer device is retracted to an outside of the process chamber201. Then, the gate valve244is closed to seal (close) an inside of the process chamber201hermetically. Thereafter, by elevating the susceptor217using the susceptor elevator268, the wafer200is placed on and supported by an upper surface of the susceptor217.

Temperature Elevation and Vacuum Exhaust Step S120

Subsequently, a temperature of the wafer200loaded into the process chamber201is elevated. The heater217B is heated in advance, and the wafer200is held by the susceptor217in which the heater217B is embedded. Thereby, for example, the wafer200is heated to a predetermined temperature within a range from 150° C. to 750° C. Further, while the wafer200is being heated, the vacuum pump246vacuum-exhausts the inner atmosphere of the process chamber201through the gas exhaust pipe231such that an inner pressure of the process chamber201reaches and is maintained at a predetermined pressure. The vacuum pump246continuously vacuum-exhausts the inner atmosphere of the process chamber201at least until a substrate unloading step S160described later is completed.

Reactive Gas Supply Step S130

Subsequently, the oxygen-containing gas and the hydrogen-containing gas are supplied into the process chamber201as the reactive gas. Specifically, the valves253A and253B are opened to start a supply of the oxygen-containing gas and a supply of the hydrogen-containing gas, respectively, into the process chamber201while flow rates of the oxygen-containing gas and the hydrogen-containing gas are adjusted by the MFCs252A and252B, respectively. In the reactive gas supply step S130, for example, the flow rate of the oxygen-containing gas is set to a predetermined flow rate within a range from 20 sccm to 2,000 sccm. In addition, for example, the flow rate of the hydrogen-containing gas is set to a predetermined flow rate within a range from 20 sccm to 1,000 sccm.

In the reactive gas supply step S130, the inner atmosphere of the process chamber201is exhausted by adjusting the opening degree of the APC valve242such that, for example, the inner pressure of the process chamber201is at a predetermined pressure within a range from 1 Pa to 250 Pa. The oxygen-containing gas and the hydrogen-containing gas are continuously supplied into the process chamber201while appropriately exhausting the inner atmosphere of the process chamber201until a plasma processing step S140described later is completed.

For example, as the oxygen-containing gas, a gas such as oxygen (O2) gas, nitrogen peroxide (N2O) gas, nitrogen monoxide (NO) gas, nitrogen dioxide (NO2) gas, ozone (O3) gas, water vapor (H2O gas), carbon monoxide (CO) gas and carbon dioxide (CO2) gas may be used. In addition, one or more of the gases described above may be used as the oxygen-containing gas.

Further, for example, as the hydrogen-containing gas, a gas such as hydrogen (H2) gas, deuterium (D2) gas, the H2O gas and ammonia (NH3) gas may be used. In addition, one or more of the gases described above may be used as the hydrogen-containing gas. When the H2O gas is used as the oxygen-containing gas, it is preferable that a gas other than the H2O gas is used as the hydrogen-containing gas. In addition, when the H2O gas is used as the hydrogen-containing gas, it is preferable that a gas other than the H2O gas is used as the oxygen-containing gas.

For example, as the inert gas, nitrogen (N2) gas may be used. In addition, a rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas and xenon (Xe) gas may be used as the inert gas. For example, one or more of the gases described above may be used as the inert gas.

Plasma Processing Step S140

In the plasma processing step S140, first, while supplying the process gas through the gas supplier, the RF power is supplied from the RF power supplier271to the first resonance coil212without supplying the RF power from the RF power supplier281to the second resonance coil214. Specifically, when the inner pressure of the process chamber201is stabilized, a supply of the RF power is started for the first resonance coil212from the RF power supply273via the RF sensor272.

Thereby, a high frequency electromagnetic field is formed in the plasma generation space201A to which the oxygen-containing gas and the hydrogen-containing gas are supplied. As a result, the donut-shaped ICP310whose plasma density is the highest at a height corresponding to the electrical midpoint of the first resonance coil212in the plasma generation space201A is excited by the high frequency electromagnetic field. The oxygen-containing gas and the hydrogen-containing gas are excited into a plasma state and dissociate. As a result, reactive species such as oxygen radicals containing oxygen (oxygen active species), oxygen ions, hydrogen radicals containing hydrogen (hydrogen active species) and hydrogen ions can be generated.

The radicals generated by the induction plasma and non-accelerated ions are uniformly supplied into the trench of the wafer200placed on the susceptor217in the substrate processing space201B. Then, the radicals and the ions uniformly supplied into the trench of the wafer200uniformly react with a layer (for example, the silicon layer) formed on a surface of the inner wall of the trench. Thereby, the layer formed on the surface of the inner wall of the trench is modified into an oxide layer (for example, a silicon oxide layer) whose step coverage is good.

After a predetermined process time (for example, 10 seconds to 300 seconds) has elapsed, the supply of the RF power from the RF power supply273is stopped.

Subsequently, while supplying the process gas through the gas supplier, the RF power is supplied from the RF power supplier281to the second resonance coil214without supplying the RF power from the RF power supplier271to the first resonance coil212. Specifically, when the inner pressure of the process chamber201is stabilized, a supply of the RF power is started for the second resonance coil214from the RF power supply283via the RF sensor282.

Thereby, a high frequency electromagnetic field is formed in the plasma generation space201A to which the oxygen-containing gas and the hydrogen-containing gas are supplied. As a result, the donut-shaped ICP312whose plasma density is the highest at a height corresponding to the electrical midpoint of the second resonance coil214in the plasma generation space201A is excited by the high frequency electromagnetic field. The oxygen-containing gas and the hydrogen-containing gas are excited into the plasma state and dissociate. As a result, the reactive species such as the oxygen radicals containing oxygen (the oxygen active species), the oxygen ions, the hydrogen radicals containing hydrogen (hydrogen active species) and the hydrogen ions can be generated.

The radicals generated by the induction plasma (that is, the donut-shaped ICP312), the radicals generated by the induction plasma (that is, the donut-shaped ICP310) generated by the first resonance coil212and whose lifetime is extended in the present step and non-accelerated ions are uniformly supplied into the trench of the wafer200placed on the susceptor217in the substrate processing space201B. Then, the radicals and the ions uniformly supplied into the trench of the wafer200uniformly react with the layer (for example, the silicon layer) formed on the surface of the inner wall of the trench. Thereby, the layer formed on the surface of the inner wall of the trench is modified into the oxide layer (for example, the silicon oxide layer) whose step coverage is good.

After a predetermined process time (for example, 10 seconds to 300 seconds) has elapsed, the supply of the RF power from the RF power supply283is stopped. Thereby, the plasma discharge in the process chamber201is stopped.

In addition, the valves253A and253B are closed to stop the supply of the oxygen-containing gas and the supply of the hydrogen-containing gas into the process chamber201. Thereby, the plasma processing step S140is completed.

Vacuum Exhaust Step S150

After the supply of the oxygen-containing gas and the supply of the hydrogen-containing gas are stopped, the inner atmosphere of the process chamber201is vacuum-exhausted through the gas exhaust pipe231. Thereby, the gas such as the oxygen-containing gas, the hydrogen-containing gas and an exhaust gas generated from the reaction therebetween in the process chamber201is exhausted to the outside of the process chamber201. Thereafter, the opening degree of the APC valve242is adjusted such that the inner pressure of the process chamber201is adjusted to the same pressure as that of the vacuum transfer chamber (not shown) provided adjacent to the process chamber201. The vacuum transfer chamber serves as an unloading destination of the wafer200.

Substrate Unloading Step S160

After the inner pressure of the process chamber201is adjusted to a predetermined pressure, the susceptor217is lowered to the transfer position of the wafer200until the wafer200is supported by the wafer lift pins266. Then, the gate valve244is opened, and the wafer200is transferred (unloaded) out of the process chamber201by using the wafer transfer device (not shown).

Thereby, the substrate processing according to the present embodiments is completed.

Other Embodiments

While the technique of the present disclosure is described in detail by way of the embodiments described above, the technique of the present disclosure is not limited thereto. For example, the embodiments described above may be appropriately combined.

For example, the above-described embodiments are described by way of an example in which the second arrangement region SA is provided closer to the susceptor217than the first arrangement region FA in the up-and-down direction of the substrate processing apparatus100(that is, the vertical direction). However, the technique of the present disclosure is not limited thereto. For example, the second arrangement region SA may be provided farther from the susceptor217than the first arrangement region FA in the up-and-down direction of the substrate processing apparatus100(that is, the vertical direction).

For example, the above-described embodiments are described by way of an example in which the first arrangement region FA and the second arrangement region SA are provided on the outer periphery of the process vessel203as shown inFIG.8. However, the technique of the present disclosure is not limited thereto. For example, as shown inFIG.12, a third arrangement region TA may be provided opposite to the first arrangement region FA with the second arrangement region SA provided therebetween. In the third arrangement region TA, the conductor212A of the first resonance coil212and the conductor214A of the second resonance coil214are alternately arranged in the vertical direction (that is, the axial direction of each resonance coil). In such a case, by grounding the both ends of the first resonance coil212, it is possible to provide the multiple of the wavelength of the RF power supplied to the first resonance coil212. Thereby, it is possible to provide the sine curve of the voltage. As a result, it is possible to easily control the peak of the voltage distribution of the first resonance coil212.

For example, the above-described embodiments are described by way of an example in which the axial length of the coil portion of the first resonance coil212is set to be different from the axial length of the coil portion of the second resonance coil214. However, the technique of the present disclosure is not limited thereto. For example, the axial length of the coil portion of the first resonance coil212may be the same as the axial length of the coil portion of the second resonance coil214. In such a case, for example, the first resonance coil212and the second resonance coil214may be arranged such that the first resonance coil212entirely overlaps with the second resonance coil214, or such that a lower portion of the first resonance coil212overlaps with an upper portion of the second resonance coil214. Further, even when the axial length of the coil portion of the first resonance coil212is set to be different from the axial length of the coil portion of the second resonance coil214, the first resonance coil212and the second resonance coil214may be arranged such that a part of the coil portion of the first resonance coil212in the axial direction overlaps with a part of the coil portion of the second resonance coil214in the axial direction.

For example, the above-described embodiments are described by way of an example in which the process chamber201defined by the process vessel203includes the plasma generation room and the substrate processing room (That is, the plasma generation room and the substrate processing room are configured by the same process vessel203). However, the technique of the present disclosure is not limited thereto. For example, the plasma generation room and the substrate processing room may be configured as separate vessels.

For example, the above-described embodiments are described by way of an example in which the oxidation process using the plasma is performed onto the surface of the substrate. However, the technique of the present disclosure is not limited thereto. For example, a nitridation process using a nitrogen-containing gas as the process gas may be performed. Further, the technique of the present disclosure is not limited to the nitridation process and the oxidation process, and may be applied to other processing techniques of processing the substrate using the plasma. For example, the technique of the present disclosure may be applied to a process such as a modification process onto a film formed on the surface of the substrate, a doping process, a reduction process of an oxide film, an etching process with respect to the film and a photoresist ashing process, which are performed by using the plasma.

For example, the above-described embodiments are described by way of an example in which the two resonance coils are used. However, the technique of the present disclosure is not limited thereto. For example, three or more resonance coils may be used.

For example, the above-described embodiments are described by way of the embodiments and modified examples described above. However, the technique of the present disclosure is not limited thereto. It is apparent to the person skilled in the art that the technique of the present disclosure may be modified in various ways without departing from the scope thereof.

According to some embodiments of the present disclosure, it is possible to improve the uniformity of the substrate processing on the surface of the substrate.