JP5702584B2 - Semiconductor device manufacturing method and substrate processing apparatus - Google Patents

Description

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

  Some semiconductor devices such as CMOS (Complementary Metal Oxide Semiconductor) include a gate electrode made of a metal, for example. Such a gate electrode has a laminated structure of, for example, a titanium nitride (TiN) film that suppresses diffusion of metal to the base and a low resistance tungsten (W) film.

  However, since the TiN film and the W film are different in gas type and processing temperature used at the time of formation, they have to be formed separately in different substrate processing apparatuses (or different processing chambers). That is, it is difficult to continuously manufacture gate electrodes having a laminated structure in the same processing chamber. For this reason, there are cases where the manufacturing cost of the semiconductor device increases and the productivity decreases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device manufacturing method and a substrate processing apparatus capable of continuously forming gate electrodes having a laminated structure in the same processing chamber, reducing manufacturing costs, and improving productivity. And providing a semiconductor device.

  One embodiment of the present invention includes a substrate carrying-in process for carrying a substrate into a processing chamber, a first nitride film forming process for forming a titanium aluminum nitride film on the substrate, and a second nitride film for forming a titanium nitride film on the substrate. A semiconductor device comprising: a forming step; and a substrate unloading step for unloading the substrate from the processing chamber, wherein the first nitride film forming step and the second nitride film forming step are performed in the same processing chamber. It is a manufacturing method.

  Another aspect of the present invention is a method for manufacturing a semiconductor device configured as a CMOS including a pMOS transistor and an nMOS transistor, wherein the gate electrode of the pMOS transistor has a high titanium-to-aluminum titanium composition ratio. A film and a titanium nitride film are stacked in this order, and the gate electrode of the nMOS transistor is formed by stacking the titanium aluminum nitride film having a high composition ratio of aluminum to titanium and the titanium nitride film in this order. This is a method for manufacturing a semiconductor device.

  Still another embodiment of the present invention includes a processing chamber that accommodates a substrate, a titanium-containing gas supply system that supplies a titanium-containing gas into the processing chamber, and an aluminum-containing gas supply system that supplies an aluminum-containing gas into the processing chamber. A nitrogen-containing gas supply system for supplying a nitrogen-containing gas into the processing chamber, an exhaust system for exhausting an atmosphere in the processing chamber, and a titanium-containing gas and a nitrogen-containing gas are supplied into the processing chamber in which a substrate is accommodated. A titanium nitride film is formed on the substrate, an aluminum-containing gas and a nitrogen-containing gas are supplied into the processing chamber to form an aluminum nitride film on the substrate, and the titanium nitride film and the aluminum nitride film are formed a predetermined number of times. Titanium aluminum nitride film is formed by alternately carrying out, and a titanium containing gas and nitrogen are formed in the processing chamber in which the substrate is accommodated. A substrate comprising: a control system for controlling the titanium-containing gas supply system, the aluminum-containing gas supply system, the nitrogen-containing gas supply system, and the exhaust system so as to supply a gas and form a titanium nitride film on the substrate. It is a processing device.

  Still another aspect of the present invention is a semiconductor device configured as a CMOS including a pMOS transistor and an nMOS transistor, wherein a titanium aluminum nitride film having a high titanium to aluminum composition ratio and a titanium nitride film are stacked in this order. And a gate electrode of the nMOS transistor in which a titanium aluminum nitride film having a high composition ratio of aluminum to titanium and a titanium nitride film are stacked in this order.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a semiconductor device which can form continuously the gate electrode provided with laminated structure in the same process chamber, can reduce manufacturing cost, and can improve productivity, a substrate processing apparatus, and A semiconductor device is obtained.

1 is a perspective view of a substrate processing apparatus according to a first embodiment of the present invention. It is a block diagram of the processing furnace which concerns on 1st Embodiment of this invention, Comprising: It is a figure which shows a process chamber part with sectional drawing especially. It is a block diagram of the processing furnace which concerns on 1st Embodiment of this invention, Comprising: It is AA sectional drawing of the process chamber part of FIG. It is a flowchart which illustrates the substrate processing process concerning a 1st embodiment of the present invention. It is a gas supply timing diagram of the substrate processing process concerning a 1st embodiment of the present invention. It is sectional drawing which shows the main structure part of the transistor with which CMOS which concerns on 1st Embodiment of this invention is provided. It is a graph which shows the resistivity of the TiN film | membrane formed by ALD method, and the resistivity of the TiN film | membrane formed by CVD method, respectively. It is a flowchart which illustrates the substrate processing process which concerns on 2nd Embodiment of this invention. It is a gas supply timing diagram of the substrate processing process concerning a 2nd embodiment of the present invention. It is the gas supply timing diagram of the substrate processing process which concerns on the modification 1 of 2nd Embodiment of this invention, Comprising: (a) is the figure which extended supply time of titanium containing gas, (b) is the figure of aluminum containing gas. It is the figure which extended supply time. It is the gas supply timing diagram of the substrate processing process which concerns on the modification 2 of 2nd Embodiment of this invention, Comprising: (a) is the figure which increased the supply flow rate of titanium containing gas, (b) is the figure of aluminum containing gas. It is the figure which increased supply flow volume. It is the gas supply timing diagram of the substrate processing process which concerns on the modification 3 of 2nd Embodiment of this invention, Comprising: (a) is the figure which reduced the frequency | count of supply of aluminum containing gas, (b) is a figure of titanium containing gas. It is the figure which reduced the frequency | count of supply. It is a gas supply timing diagram of the substrate processing process concerning a 3rd embodiment of the present invention. It is a gas supply timing diagram of the substrate processing process which concerns on the modification of 3rd Embodiment of this invention. It is a gas supply timing diagram of the substrate processing process concerning a 4th embodiment of the present invention. It is a gas supply timing diagram of the substrate processing process which concerns on the modification of 4th Embodiment of this invention. It is a gas supply timing diagram of the substrate processing process concerning a 5th embodiment of the present invention. It is a gas supply timing diagram of the substrate processing process which concerns on the modification of 5th Embodiment of this invention. It is sectional drawing which shows the main structure part of the transistor with which the CMOS of a prior art example is provided.

<Knowledge obtained by the inventor>
First, prior to the description of the embodiment of the present invention, knowledge obtained by the inventors will be described.

  FIG. 19 illustrates cross-sectional configurations of a pMOS transistor 500p and an nMOS transistor 500n included in a conventional CMOS. Each transistor includes a wafer 200 such as a silicon (Si) substrate, hafnium oxide (HfO) films 510p and 510n as gate insulating films, titanium nitride (TiN) films 521p and 521n as diffusion suppression films, and low resistance metal films. As a stacked structure in which tungsten (W) films 522p and 522n are sequentially formed.

  The TiN films 521p and 521n have a higher resistivity than the W films 522p and 522n, and are inferior in characteristics. , 522n is prevented from diffusing into the HfO films 510p, 510n (metal contamination of the gate insulating film), or the oxygen (O) W films 522p, 522n constituting the HfO films 510p, 510n. Can be suppressed (oxidation of the gate electrode). Therefore, the gate electrode is not composed of a single layer such as a W film, but is composed of a laminated structure of a TiN film and a W film. In FIG. 19, the gate electrode of the pMOS transistor 500p is formed by stacking the TiN film 521p and the W film 522p, and the gate electrode of the nMOS transistor 500n is formed by stacking the TiN film 521n and the W film 522n. It is configured.

  The TiN films 521p and 521n and the W films 522p and 522n constituting the gate electrode are each formed by a CVD (Chemical Vapor Deposition) method or the like. However, since the TiN films 521p and 521n and the W films 522p and 522n have different gas types, processing temperatures, and the like, they must be formed separately in different substrate processing apparatuses (or different processing chambers). That is, it is difficult to continuously manufacture gate electrodes having a laminated structure in the same processing chamber. For this reason, the number of apparatuses increases and the manufacturing cost increases, and it may take time to load and unload the wafer 200, resulting in a decrease in productivity. Further, when the wafer 200 is transferred during the formation of the gate electrode, the TiN films 521p, 521n and the like constituting the lower layer of the gate electrode may be exposed to the atmosphere, and the characteristics may be impaired.

  Therefore, the present inventors have made various attempts to solve the above problems. That is, earnest research was conducted on the combination of laminated structures that can be continuously formed in the same processing chamber. As a result, by forming, for example, a TiN film instead of the W films 522p and 522n as the upper layer (low resistance metal film) of the gate electrode, the gate electrode having a laminated structure can be continuously formed in the same processing chamber. We have learned that it will be possible. In addition, the TiN film constituting the upper layer of the gate electrode is formed not by the conventional CVD method but by the ALD (Atomic Layer Deposition) method, so that the electrical characteristics of the TiN film can be improved and the characteristics of the semiconductor device can be improved. The knowledge that it can improve was obtained. Further, as a lower layer (diffusion suppression film) of the gate electrode, a TiAlN film is formed instead of the TiN films 521p and 521n, and further, the composition ratio of Ti and Al in the TiAlN film is adjusted to a predetermined value, thereby providing a semiconductor. We have learned that the characteristics of the device can be further improved. The present invention is based on the above findings found by the inventors.

<First Embodiment of the Present Invention>
First, the configuration of the substrate processing apparatus according to the first embodiment of the present invention will be described.

(1) Overall Configuration of Substrate Processing Apparatus FIG. 1 is a perspective view of a substrate processing apparatus 101 according to this embodiment. As shown in FIG. 1, the substrate processing apparatus 101 according to the present embodiment includes a housing 111. In order to transport the wafer 200 as a substrate into and out of the casing 111, a cassette 110 as a wafer carrier (substrate storage container) that stores a plurality of wafers 200 is used. A cassette loading / unloading port (substrate storage container loading / unloading port, not shown), which is an opening for conveying the cassette 110 into and out of the housing 111, is provided on the front surface of the housing 111. A cassette stage (substrate storage container delivery table) 114 is provided inside the cassette loading / unloading casing 111. The cassette 110 is placed on the cassette stage 114 by an in-factory transport device (not shown), and is carried out of the casing 111 from the cassette stage 114.

  The cassette 110 is configured to be placed on the cassette stage 114 by a transfer device in the factory so that the wafer 200 in the cassette 110 is in a vertical posture and the wafer loading / unloading port of the cassette 110 faces upward. . The cassette stage 114 rotates the cassette 110 90 degrees toward the rear of the casing 111 to bring the wafer 200 in the cassette 110 into a horizontal posture, and directs the wafer loading / unloading port of the cassette 110 toward the rear in the casing 111. Is configured to be possible.

  A cassette shelf (substrate storage container mounting shelf) 105 is installed in a substantially central portion of the housing 111 as viewed in the front-rear direction. The cassette shelf 105 is configured to store a plurality of cassettes 110 in a plurality of rows and a plurality of rows. The cassette shelf 105 is provided with a transfer shelf 123 in which a cassette 110 to be transferred by a wafer transfer mechanism 125 described later is stored. In addition, a spare cassette shelf 107 is provided above the cassette stage 114 and is configured to store the spare cassette 110.

  A cassette transfer device (substrate container transfer device) 118 is provided between the cassette stage 114 and the cassette shelf 105. The cassette transport device 118 includes a cassette elevator (substrate storage container lifting mechanism) 118a that can be moved up and down while holding the cassette 110, and a cassette transport mechanism (substrate storage container transport mechanism) as a transport mechanism that can move horizontally while holding the cassette 110. 118b. The cassette 110 is transported between a predetermined position of the cassette shelf 105 excluding the cassette stage 114 and the transfer shelf 123, the spare cassette shelf 107, and the transfer shelf 123 by the cooperative operation of the cassette elevator 118a and the cassette transport mechanism 118b. It is configured as follows.

  A wafer transfer mechanism (substrate transfer mechanism) 125 is provided behind the cassette shelf 105. The wafer transfer mechanism 125 includes a wafer transfer device (substrate transfer device) 125a that can rotate or linearly move the wafer 200 in the horizontal direction, and a wafer transfer device elevator (substrate transfer device) that moves the wafer transfer device 125a up and down. Elevating mechanism) 125b. The wafer transfer device 125a includes a tweezer (substrate holder) 125c that holds the wafer 200 in a horizontal posture. The wafer 200 is picked up from the cassette 110 on the transfer shelf 123 by the cooperative operation of the wafer transfer device 125a and the wafer transfer device elevator 125b, and loaded into a boat (substrate holder) 217 described later (wafer charge). The wafer 200 is removed from the boat 217 (wafer discharge) and stored in the cassette 110 on the transfer shelf 123.

  A processing furnace 202 is provided above the rear portion of the casing 111. An opening is provided at the lower end of the processing furnace 202, and the opening is configured to be opened and closed by a furnace port shutter (furnace port opening / closing mechanism) 147. The configuration of the processing furnace 202 will be described later.

Below the processing furnace 202, a transfer chamber 124, which is a space for loading and unloading the wafers 200 into and from the boat (substrate holder) 217 from the cassette 110 on the transfer shelf 123, is provided. In the transfer chamber 124, a boat elevator (substrate holder lifting mechanism) 115 is provided as a lifting mechanism that lifts and lowers the boat 217 into and out of the processing furnace 202. The elevator 128 of the boat elevator 115 is provided with an arm 128 as a connecting tool. On the arm 128, a seal cap 219 is provided in a horizontal posture as a furnace port lid body that supports the boat 217 vertically and that hermetically closes the lower end of the processing furnace 202 when the boat 217 is raised by the boat elevator 115. It has been.

  The boat 217 includes a plurality of holding members, and a plurality of (for example, about 50 to 150) wafers 200 are aligned in the vertical direction in a horizontal posture and in a state where the centers thereof are aligned in multiple stages. Configured to hold.

  Above the cassette shelf 105, a clean unit 134a having a supply fan and a dustproof filter is provided. The clean unit 134a is configured to circulate clean air, which is a cleaned atmosphere, inside the casing 111.

  In addition, a clean unit (not shown) including a supply fan and a dustproof filter is installed on the opposite side of the wafer transfer device elevator 125b and the boat elevator 115 and on the left end of the housing 111 to supply clean air. Has been. The clean air blown from the clean unit is configured to be sucked into an exhaust device (not shown) and exhausted to the outside of the casing 111 after passing through the wafer transfer device 125a and the boat 217.

(2) Operation of Substrate Processing Apparatus Next, the operation of the substrate processing apparatus 101 according to the present embodiment will be described.

  First, the cassette 110 is loaded from a cassette loading / unloading port (not shown) by the in-factory transfer device, the wafer 200 is placed in a vertical posture, and the wafer loading / unloading port of the cassette 110 faces upward. Placed. Thereafter, the cassette 110 is rotated 90 ° toward the rear of the casing 111 by the cassette stage 114. As a result, the wafer 200 in the cassette 110 assumes a horizontal posture, and the wafer loading / unloading port of the cassette 110 faces rearward in the housing 111.

  Next, the cassette 110 is automatically transported to the designated shelf position of the cassette shelf 105 (excluding the transfer shelf 123) or the spare cassette shelf 107 by the cassette transport device 118, delivered, and temporarily stored. Then, the cassette is transferred from the cassette shelf 105 or the spare cassette shelf 107 to the transfer shelf 123 or directly transferred to the transfer shelf 123.

  When the cassette 110 is transferred to the transfer shelf 123, the wafer 200 is picked up from the cassette 110 through the wafer loading / unloading port by the tweezer 125c of the wafer transfer device 125a, and the wafer transfer device 125a and the wafer transfer device elevator 125b are picked up. Are loaded (wafer charged) into the boat 217 behind the transfer chamber 124. The wafer transfer mechanism 125 that has transferred the wafer 200 to the boat 217 returns to the cassette 110 and loads the next wafer 200 into the boat 217.

When a predetermined number of wafers 200 are loaded into the boat 217, the furnace port shutter 147 that has closed the lower end of the processing furnace 202 is opened. Subsequently, as the seal cap 219 is raised by the boat elevator 115, the boat 217 holding the wafers 200 is loaded into the processing furnace 202 (boat loading). After boat loading, arbitrary processing is performed on the wafer 200 in the processing furnace 202. Such processing will be described later. After the processing, the wafer 200 and the cassette 110 are carried out of the casing 111 by a procedure reverse to the above procedure.

(3) Configuration of Processing Furnace Next, the configuration of the processing furnace 202 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is a configuration diagram of the processing furnace 202 of the substrate processing apparatus 101 shown in FIG. 1, and particularly shows a processing chamber 201 portion in a sectional view. 3 is a cross-sectional view taken along the line AA of the processing chamber portion of FIG.

(Processing room)
The processing furnace 202 according to the present embodiment is configured as a batch type vertical hot wall type processing furnace by, for example, the ALD method. As shown in FIG. 2, the processing furnace 202 includes a reaction tube 203 and a manifold 209. The reaction tube 203 is made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with its upper end closed and its lower end open. The manifold 209 is made of, for example, a metal material such as SUS, and has a cylindrical shape with an upper end portion and a lower end portion opened. The reaction tube 203 is supported vertically by the manifold 209 from the lower end side. An annular flange is provided at each of the lower end of the reaction tube 203 and the upper and lower opening ends of the manifold 209. A sealing member 220 such as an O-ring is provided between the lower end portion of the reaction tube 203 and the flange at the upper end portion of the manifold 209, and the space between the two is hermetically sealed.

  Inside the reaction tube 203 and the manifold 209, a processing chamber 201 for storing a plurality of stacked wafers 200 as substrates is formed. The boat 217 as the substrate holder is configured to be inserted into the processing chamber 201 from below by the boat elevator 115 as the substrate holder lifting mechanism described above.

  The boat 217 is configured to hold a plurality of (for example, about 50 to 150) wafers 200 in multiple stages with a predetermined gap (substrate pitch interval) in a substantially horizontal state. The maximum outer diameter of the boat 217 loaded with the wafers 200 is configured to be smaller than the inner diameters of the reaction tube 203 and the manifold 209. The boat 217 is mounted on the seal cap 219 via a boat support 218 as a holding body that holds the boat 217. The seal cap 219 is configured to contact the lower end of the manifold 209 from the lower side in the vertical direction. The seal cap 219 is made of a metal such as SUS and is formed in a disk shape. When the boat elevator 115 is raised, the sealing member 220 provided between the flange at the lower end of the manifold 209 and the seal cap 219 is configured to be hermetically sealed between the two. Since the space between the reaction tube 203 and the manifold 209 and the space between the manifold 209 and the seal cap 219 are hermetically sealed, the airtightness in the processing chamber 201 is maintained. Further, the boat 217 can be transported into and out of the processing chamber 201 by raising and lowering the seal cap 219 in the vertical direction by the boat elevator 115.

  A rotation mechanism 267 is provided below the seal cap 219. The rotation shaft 255 of the rotation mechanism 267 is connected to the boat 217 through the seal cap 219, and can rotate the boat 217 on which a plurality of wafers 200 are mounted while maintaining the airtightness in the processing chamber 201. It is configured to be able to. By rotating the boat 217, the processing uniformity of the wafers 200 can be improved.

On the outer periphery of the reaction tube 203, a heater 207 as a heating unit is provided in a cylindrical shape concentric with the reaction tube 203, and the wafer 200 inserted into the processing chamber 201 is heated to a predetermined temperature. Has been. The heater 207 is vertically installed by being supported by a heater base 210 as a holding plate. The heater base 210 is connected to the manifold 20.
9 is fixed.

  A temperature sensor 263 is installed in the reaction tube 203 as a temperature detector. Based on the temperature information detected by the temperature sensor 263, the temperature in the processing chamber 201 is configured to have a desired temperature distribution by adjusting the power supply to the heater 207. The temperature sensor 263 is configured in an L shape similarly to the porous nozzles 270a, 270b, and 270c described later, and is provided along the inner wall of the reaction tube 203.

(Porous nozzle)
The manifold 209 is provided with multi-hole nozzles 270a, 270b, and 270c. The perforated nozzles 270a, 270b, and 270c are each configured in an L shape having a vertical portion and a horizontal portion. The vertical portions of the perforated nozzles 270a, 270b, and 270c are arranged in the vertical direction along the stacking direction of the wafers 200 along the inner wall of the processing chamber 201, respectively. The horizontal portions of the perforated nozzles 270a, 270b, and 270c are provided so as to penetrate the side walls of the manifold 209, respectively.

  A plurality of gas supply ports 248a, 248b, 248c are respectively provided on the vertical side surfaces of the porous nozzles 270a, 270b, 270c so as to be arranged in the vertical direction. The gas supply ports 248a, 248b, and 248c are configured to open between the stacked wafers 200, respectively. The gas supply ports 248a, 248b, and 248c are configured to face substantially the center in the processing chamber 201 (substantially the center of the wafer 200 loaded into the processing chamber 201), respectively, and the gas supply ports 248a, 248b, and 248c are configured. Are supplied so as to be injected toward the substantial center in the processing chamber 201. The opening diameters of the gas supply ports 248a, 248b, 248c may be the same from the lower part to the upper part, or may gradually increase from the lower part to the upper part.

  The porous nozzle 270a is provided at a position close to the porous nozzles 270b and 270c as shown in FIG. However, in FIG. 2, for the sake of convenience, the porous nozzle 270a is illustrated at a position on the right side of the drawing facing the porous nozzles 270b and 270c.

(Nitrogen-containing gas supply system)
A downstream end of a nitrogen-containing gas supply pipe 232a that supplies ammonia (NH ₃ ) gas as a nitrogen (N) -containing gas (nitriding agent), for example, is connected to the upstream end (horizontal end) of the porous nozzle 270a. The nitrogen-containing gas supply pipe 232a is provided with an NH ₃ gas supply source (not shown), a mass flow controller 241a that is a flow rate control mechanism, and a valve 252a that is an on-off valve in order from the upstream side.

A downstream end of an inert gas supply pipe 234a that supplies an inert gas such as N ₂ gas as a carrier gas and a purge gas is connected to the downstream side of the valve 252a. The inert gas supply pipe 234a is provided with an inert gas supply source (not shown), a mass flow controller (not shown), and a valve 254a in order from the upstream side. By opening the valves 252a and 254a, the NH ₃ gas whose flow rate is controlled by the mass flow controller 241a can be supplied into the processing chamber 201 together with an inert gas as a carrier gas.

In addition, by opening the valve 254a with the valve 252a closed, an inert gas as a purge gas can be supplied into the processing chamber 201 while controlling the flow rate by a mass flow controller (not shown). By supplying the inert gas, for example, after the supply of the NH ₃ gas is finished, the NH ₃ gas remaining in the processing chamber 201 is excluded, or the nitrogen-containing gas supply of other gases supplied into the processing chamber 201 is performed. Back flow into the tube 232a can be prevented. Note that a purge gas supply pipe for supplying the purge gas and a carrier gas supply pipe for supplying the carrier gas may be provided separately.

Mainly nitrogen-containing gas supply pipe 232a, NH ₃ gas supply source, mass flow controller 241a, valve 252a, inert gas supply pipe 234a, inert gas supply source, mass flow controller, valve 254a, perforated nozzle 270a, gas supply port 248a Thus, a nitrogen-containing gas supply system for supplying NH ₃ gas as a nitrogen-containing gas into the processing chamber 201 is configured. In addition, a carrier gas and a purge gas are introduced into the processing chamber 201 mainly by an inert gas supply pipe 234a, an inert gas supply source, a mass flow controller, a valve 254a, a nitrogen-containing gas supply pipe 232a, a porous nozzle 270a, and a gas supply port 248a. An inert gas supply system for supplying an inert gas is configured.

(Aluminum-containing gas supply system)
Hereinafter, the case where TMA gas obtained by vaporizing TMA (trimethylaluminum: (CH ₃ ) ₃ Al) as a liquid raw material is used as the aluminum (Al) -containing gas will be described. As a method of vaporizing liquid TMA and supplying it into the processing chamber 201, a method of heating and vaporizing TMA, or supplying helium (He) gas, neon (Ne) gas, argon (which is a carrier gas) There is a method of supplying TMA gas obtained by supplying an inert gas such as Ar) gas and nitrogen (N ₂ ) gas into liquid TMA into the processing chamber 201 together with the carrier gas (bubbling method). is there. Hereinafter, for example, a case where a bubbling method is used will be described.

  A downstream end of an Al-containing gas supply pipe 233b that supplies TMA gas as an Al-containing gas is connected to the upstream end (horizontal end) of the porous nozzle 270b. A carrier gas supply pipe 232b for supplying a carrier gas is provided on the further upstream side of the Al-containing gas supply pipe 233b via the TMA container 261b. The carrier gas supply pipe 232b is provided with a carrier gas supply source, a mass flow controller 241b, a valve 252b, and a TMA container 261b (not shown) in order from the upstream side. A TMA liquid is stored in the TMA container 261b. The downstream end of the carrier gas supply pipe 232b is immersed in the TMA liquid. The upstream end of the Al-containing gas supply pipe 233b is disposed above the liquid surface of the TMA in the TMA container 261b. A valve 253b is provided on the downstream side of the Al-containing gas supply pipe 233b. The downstream end of the Al-containing gas supply pipe 233b is connected to the upstream end of the porous nozzle 270b as described above. The Al-containing gas supply pipe 233b is provided with a heater 281b. The heater 281b is configured such that the Al-containing gas supply pipe 233b can be maintained at about 50 ° C. to 60 ° C., for example. By opening the valve 252b, the carrier gas is supplied from the carrier gas supply source into the TMA container 261b while the flow rate is controlled by the mass flow controller 241b, so that the vaporized gas of TMA can be generated. The TMA gas vaporized in the TMA container 261b can be supplied into the processing chamber 201 together with the carrier gas by opening the valve 253b.

  The inside of the TMA container 261b may be configured to be heatable by a heater (not shown). By adjusting the heating temperature with the heater, the TMA gas supply flow rate into the processing chamber 201 can be controlled by promoting or suppressing the generation of vaporized TMA gas.

The upstream end of the gas exhaust pipe 236b is connected to the upstream side of the valve 253b of the Al-containing gas supply pipe 233b. A valve 256b is provided in the gas exhaust pipe 236b. The downstream end of the gas exhaust pipe 236b is connected to the downstream side of the APC valve 251 of the exhaust pipe 231 described later. By opening the valve 256b, the TMA gas can be exhausted without going through the processing chamber 201. Since a predetermined time is required to stably generate the TMA gas, the carrier gas is supplied into the TMA container 261b while the supply of the TMA gas into the processing chamber 201 is stopped. It is desirable to continue production. The structure is such that the supply start and stop of supply of TMA gas into the processing chamber 201 can be quickly performed by switching the opening and closing of the valve 253b and the valve 256b while the generation of the TMA gas by the carrier gas is continued. Has been.

  A downstream end of an inert gas supply pipe 234b that supplies an inert gas is connected to the downstream side of the valve 253b of the Al-containing gas supply pipe 233b. The inert gas supply pipe 234b is provided with an inert gas supply source (not shown), a mass flow controller (not shown), and a valve 254b in order from the upstream side. By opening the valve 254b, an inert gas as a purge gas can be supplied into the processing chamber 201 from an inert gas supply source while controlling the flow rate by a mass flow controller. By supplying the inert gas, for example, after the supply of the TMA gas is finished, the TMA gas remaining in the processing chamber 201 is excluded, or an Al-containing gas supply pipe 233b of another gas supplied into the processing chamber 201 is obtained. It is possible to prevent backflow into the inside.

  Mainly, carrier gas supply pipe 232b, carrier gas supply source, mass flow controller 241b, valve 252b, TMA container 261b, Al-containing gas supply pipe 233b, valve 253b, gas exhaust pipe 236b, valve 256b, perforated nozzle 270b, gas supply port 248b constitutes an aluminum-containing gas supply system that supplies TMA gas as an Al-containing gas into the processing chamber 201. In addition, an inert gas supply pipe 234b, an inert gas supply source, a mass flow controller, a valve 254b, an Al-containing gas supply pipe 233b, a porous nozzle 270b, and a gas supply port 248b are mainly used as purge gas in the processing chamber 201. An inert gas supply system for supplying the active gas is configured.

(Titanium-containing gas supply system)
Hereinafter, as a titanium (Ti) -containing gas, for example, a case where TiCl ₄ gas obtained by vaporizing tetrachlorotitanium (TiCl ₄ ) as a liquid source will be described. As a method for vaporizing and supplying liquid TiCl ₄ into the processing chamber 201, a method of supplying TiCl ₄ after heating and vaporizing, as in TMA, or an inert gas serving as a carrier gas is liquid TiCl 4. ₄ is a method of supplying TiCl ₄ gas obtained by supplying the gas into the processing chamber 201 together with the carrier gas into the processing chamber 201 (bubbling method). Hereinafter, for example, a case where a bubbling method is used will be described.

A downstream end of a Ti-containing gas supply pipe 233c that supplies TiCl ₄ gas as a Ti-containing gas is connected to the upstream end (horizontal end) of the porous nozzle 270c. A carrier gas supply pipe 232c for supplying a carrier gas is provided on the further upstream side of the Ti-containing gas supply pipe 233c via a TiCl ₄ container 261c. The carrier gas supply pipe 232c is provided with a carrier gas supply source, a mass flow controller 241c, a valve 252c, and a TiCl ₄ container 261c (not shown) in order from the upstream side. The TiCl ₄ container 261c liquid TiCl ₄ is stored. The downstream end of the carrier gas supply pipe 232c is immersed in a TiCl ₄ liquid. The upstream end of the Ti-containing gas supply pipe 233c is disposed above the liquid surface of TiCl ₄ in the TiCl ₄ container 261 c. A valve 253c is provided on the downstream side of the Ti-containing gas supply pipe 233c. The downstream end of the Ti-containing gas supply pipe 233c is connected to the upstream end of the porous nozzle 270c as described above. The Ti-containing gas supply pipe 233c is provided with a heater 281c. The heater 281c is configured so that the Ti-containing gas supply pipe 233c can be maintained at about 40 ° C., for example. By opening the valve 252c, the carrier gas is supplied from the carrier gas supply source into the TiCl ₄ container 261c while the flow rate is controlled by the mass flow controller 241c, so that the vaporized gas of TiCl ₄ can be generated. Yes. And by opening the valve 253c,
TiCl ₄ is configured so as is possible the TiCl ₄ gas vaporized in the container 261c is supplied into the process chamber 201 together with the carrier gas.

The TiCl ₄ container 261c may be configured to be heatable by a heater (not shown). By adjusting the heating temperature with the heater, the generation flow of TiCl ₄ vaporized gas is promoted or suppressed, and the supply flow rate of TiCl ₄ gas into the processing chamber 201 can be controlled.

The upstream end of the gas exhaust pipe 236c is connected to the upstream side of the valve 253c of the Ti-containing gas supply pipe 233c. A valve 256c is provided in the gas exhaust pipe 236c. The downstream end of the gas exhaust pipe 236c is connected to the downstream side of the APC valve 251 of the exhaust pipe 231 described later. By opening the valve 256c, the TiCl ₄ gas can be exhausted without going through the processing chamber 201. Order to generate a TiCl ₄ gas stably takes a predetermined time, while stopping the supply of the TiCl ₄ gas into the processing chamber 201 also supplies a carrier gas into the TiCl ₄ container 261 c, It is desirable to continue the generation of TiCl ₄ gas. By continuously opening and closing the valve 253c and the valve 256c while the generation of the TiCl ₄ gas by the carrier gas is continued, the supply start and stop of the supply of the TiCl ₄ gas into the processing chamber 201 can be performed quickly. It is configured.

A downstream end of an inert gas supply pipe 234c that supplies an inert gas is connected to the downstream side of the valve 253c of the Ti-containing gas supply pipe 233c. The inert gas supply pipe 234c is provided with an inert gas supply source (not shown), a mass flow controller (not shown), and a valve 254c in order from the upstream side. By opening the valve 254c, the inert gas as the purge gas can be supplied into the processing chamber 201 from the inert gas supply source while controlling the flow rate by the mass flow controller. By supplying an inert gas, for example, after the supply of TiCl ₄ gas is completed, TiCl ₄ gas remaining in the processing chamber 201 is excluded, or Ti-containing gas supply of other gases supplied into the processing chamber 201 is performed. Backflow into the tube 233c can be prevented.

Mainly, carrier gas supply pipe 232c, carrier gas supply source, mass flow controller 241c, valve 252c, TiCl ₄ container 261c, Ti-containing gas supply pipe 233c, valve 253c, gas exhaust pipe 236c, valve 256c, perforated nozzle 270c, gas supply A titanium-containing gas supply system that supplies TiCl ₄ gas as a Ti-containing gas into the processing chamber 201 is configured by the port 248c. In addition, an inert gas supply pipe 234b, an inert gas supply source, a mass flow controller, a valve 254c, a Ti-containing gas supply pipe 233c, a porous nozzle 270c, and a gas supply port 248c are mainly used as purge gas in the processing chamber 201. An inert gas supply system for supplying the active gas is configured.

(Exhaust system)
An exhaust pipe 231 is connected to the side wall of the manifold 209. In the exhaust pipe 231, a pressure sensor 245 as a pressure detector (pressure detection unit) that detects the pressure in the processing chamber 201, an APC (Auto Pressure Controller) valve 251 as a pressure regulator, and vacuum exhaust are sequentially provided from the upstream side. A vacuum pump 246 as an apparatus is provided. The APC valve 251 is an on-off valve that can be evacuated and stopped by opening and closing the valve and that can further adjust the opening of the valve. By adjusting the opening degree of the opening / closing valve of the APC valve 251 based on the pressure information detected by the pressure sensor 245 while operating the vacuum pump 246, the inside of the processing chamber 201 can be set to a desired pressure. It is configured.

An exhaust system that exhausts the atmosphere in the processing chamber 201 is mainly configured by the exhaust pipe 231, the pressure sensor 245, the APC valve 251, and the vacuum pump 246.

(Control system)
The controller 280 as a control system includes a mass flow controller 241a, 241b, 241c, an APC valve 251, a valve 252a, 252b, 252c, 253b, 253c, 254a, 254b, 254c, 256b, 256c, a temperature sensor 263, a heater 207, a pressure sensor. 245, a vacuum pump 246, a rotation mechanism 267, a boat elevator 115, and the like. The controller 280 adjusts the flow rate of the mass flow controllers 241a, 241b, and 241c, opens and closes the APC valve 251, valves 252a, 252b, 252c, 253b, 253c, 254a, 254b, 254c, 256b, and 256c, and adjusts the pressure of the APC valve 251. Operation, temperature sensor 263 temperature detection operation, heater 207 temperature adjustment operation, pressure sensor 245 pressure detection operation, vacuum pump 246 start / stop, rotation mechanism 267 rotation speed adjustment, boat elevator 115 lifting / lowering operation control. Done.

(4) Substrate Processing Step Next, the substrate processing step according to the present embodiment will be described. This process is performed by the above-described processing furnace 202 as one process of manufacturing a semiconductor device such as a CMOS shown in FIG. In this step, a TiAlN film as a diffusion suppression film and a TiN film as a low resistance metal film are stacked in this order on a HfO film as a high dielectric constant insulating film formed in advance on the wafer 200. These laminated films are subjected to an etching process and the like after this process, whereby a laminated film of a TiAlN film 321p and a TiN film 322p as a gate electrode of a pMOS transistor 300p, and an nMOS as shown in FIG. Each is processed into a laminated film of a TiAlN film 321n and a TiN film 322n as a gate electrode of the transistor 300n. Also, the HfO film is processed into an HfO film 310p and an HfO film 310n as gate insulating films, respectively.

  In this step, a TiAlN film constituting the lower layer (diffusion suppression film) of the gate electrode and a TiN film constituting the upper layer (low resistance metal film) of the gate electrode are formed by the ALD method. The ALD method is a method of performing film formation by alternately supplying a plurality of types of processing gases to the wafer 200 without mixing them, for example, by adsorbing them in units of several atomic layers from less than one atomic layer, and causing a surface reaction. . When forming a TiAlN film, for example, a Ti-containing gas, an Al-containing gas, and a nitrogen-containing gas are used as processing gases. When forming a TiN film, for example, a Ti-containing gas and a nitrogen-containing gas are used. At this time, the thickness of the thin film to be formed can be controlled by controlling the number of times the process gas is supplied. For example, if the film formation rate is 0.1 nm / cycle, a 2 nm thin film can be formed by performing 20 cycles. At this time, the composition of the thin film can be controlled by controlling the film formation conditions such as the supply flow rate, supply time, and processing temperature during the gas supply.

  FIG. 4 is a flowchart illustrating the substrate processing process according to this embodiment. FIG. 5 is a gas supply timing chart of the substrate processing step according to the present embodiment. In the following description, the operation of each part constituting the processing furnace 202 shown in FIG. 2 is controlled by the controller 280.

(Substrate carrying-in process S110)
First, a plurality of wafers 200 on which HfO films are formed in advance are loaded into the boat 217 (wafer charge). Then, the boat 217 holding the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201 (boat loading). In this state, the seal cap 219 is in a state of hermetically sealing the lower end of the manifold 209 via the sealing member 220. In the substrate carrying-in process S110, it is preferable that the valves 254a, 254b, and 254c are opened and an inert gas such as N ₂ gas as a purge gas is continuously supplied into the processing chamber 201.

(Decompression step S120, temperature raising step S130)
Subsequently, the valves 254a, 254b, and 254c are closed, and the inside of the processing chamber 201 is evacuated by the vacuum pump 246. Further, the power supply to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the wafer 200 is at a predetermined temperature, specifically 350 ° C. or less, for example, 350 ° C. The temperature in the chamber 201 is adjusted. Then, the rotation mechanism 267 starts the rotation of the boat 217, that is, the wafer 200.

  In parallel with Steps S110 to S130, TMA gas obtained by vaporizing TMA as a liquid material is generated (preliminary vaporization). That is, while the valve 253b is closed, the valve 252b is opened, the carrier gas is supplied into the TMA container 261b from a carrier gas supply source (not shown) while controlling the flow rate by the mass flow controller 241b, and vaporized TMA gas is generated in advance. deep. At this time, while operating the vacuum pump 246, the valve 256b is opened while the valve 253b is closed, thereby bypassing and exhausting the process chamber 201 without supplying the TMA gas into the process chamber 201.

At this time, TiCl ₄ gas obtained by vaporizing TiCl ₄ as a liquid raw material is generated (preliminary vaporization). That is, while the valve 253c is closed, the valve 252c is opened, the carrier gas is supplied into the TiCl ₄ container 261c from a carrier gas supply source (not shown) while controlling the flow rate by the mass flow controller 241c, and a vaporized gas of TiCl ₄ is generated in advance. Let me. At this time, while operating the vacuum pump 246, the valve 256c is opened while the valve 253c is closed, so that the processing chamber 201 is bypassed and exhausted without supplying the TiCl ₄ gas into the processing chamber 201. .

In the supply method by bubbling, since it takes a predetermined time for the TMA gas and TiCl ₄ gas to be stably generated, the supply becomes unstable when the supply of TMA gas or TiCl ₄ gas is started at the initial stage of generation. turn into. Therefore, in the present embodiment, as described above, TMA gas and TiCl ₄ gas are generated in advance so that they can be stably supplied, and the opening and closing of the valves 253b, 256b, 253c, and 256c is switched to open the TMA gas. And the flow path of the TiCl ₄ gas. Thereby, supply start and supply stop of the TMA gas and TiCl ₄ gas into the processing chamber 201 can be performed stably and quickly.

(First nitride film forming step)
Subsequently, a TiAlN film as a first nitride film (diffusion suppression film) is formed on the HfO film formed in advance on the wafer 200. The first nitride film forming step includes a third nitride film forming step in which steps S141a to S144a described later are performed a predetermined number of times (S145a), and a fourth nitride film in which steps S141b to S144b described later are performed a predetermined number of times (S145b). Forming a TiAlN film by alternately performing the third nitride film forming process and the fourth nitride film forming process a predetermined number of times (S150). Hereinafter, the third nitride film forming step and the fourth nitride film forming step will be described in detail.

(Third nitride film forming step)
(Titanium-containing gas supply step S141a)
In the titanium-containing gas supply step S141a, TiCl ₄ gas as a Ti-containing gas is supplied into the processing chamber 201. Specifically, by closing the valve 256c and opening the valve 253c, the supply of the TiCl ₄ gas vaporized in the TiCl ₄ container 261c into the processing chamber 201 together with the carrier gas is started. At this time, the opening degree of the APC valve 251 is adjusted to maintain the pressure in the processing chamber 201 within the range of 20 Pa to 50 Pa, for example, 30 Pa. The supply flow rate of TiCl ₄ gas is, for example, 1.0 g / min or more and 2.0 g / mi.
Within n or less. The supply time of the TiCl ₄ gas is set, for example, in the range of 3 seconds to 10 seconds. When a predetermined time has elapsed, the valve 253c is closed and the valve 256c is opened, and the supply of TiCl ₄ gas is stopped.

The TiCl ₄ gas supplied into the processing chamber 201 is supplied to the HfO film on the wafer 200 and exhausted from the exhaust pipe 231. At this time, the gas present in the processing chamber 201 is only an inert gas such as TiCl ₄ gas and N ₂ gas, and there is no nitrogen-containing gas such as NH ₃ gas. Therefore, TiCl ₄ gas causes chemical adsorption (surface reaction) with a surface portion such as an HfO film on the wafer 200 without causing a gas phase reaction, thereby forming an adsorption layer or Ti layer of TiCl ₄ molecules. The adsorption layer of TiCl ₄ molecules, in addition to a continuous adsorption layer of TiCl ₄ molecules, including a discontinuous adsorption layer. The Ti layer includes a continuous layer composed of Ti and a Ti thin film formed by overlapping these layers. In the following, all of these are also referred to as Ti-containing layers.

During the supply of TiCl ₄ gas into the processing chamber 201, the inert gas supply pipe 234a connected to the nitrogen-containing gas supply pipe 232a and the inert gas supply pipe 234b connected to the Al-containing gas supply pipe 233b are connected. If the inert gas is allowed to flow by opening the valves 254a and 254b, the TiCl ₄ gas can be prevented from flowing into the nitrogen-containing gas supply pipe 232a and the Al-containing gas supply pipe 233b.

(Exhaust process S142a)
After the valve 253c is closed and the supply of the TiCl ₄ gas into the processing chamber 201 is stopped, the APC valve 251 is opened to evacuate the processing chamber 201 so that the pressure in the processing chamber 201 becomes 20 Pa or less, for example. Residual TiCl ₄ gas and reaction products are excluded. At this time, when an inert gas such as N ₂ is supplied into the processing chamber 201 from the inert gas supply pipes 234a, 234b, and 234c and purged, the effect of removing the residual gas from the processing chamber 201 can be further enhanced. it can. After a predetermined time has elapsed, the valves 234a, 234b, 234c are closed, and the exhaust process S142a is terminated.

(Nitrogen-containing gas supply step S143a)
In the nitrogen-containing gas supply step S143a, NH ₃ gas as a nitrogen-containing gas is supplied into the processing chamber 201. Specifically, by opening the valves 252a and 254a, the supply of the NH ₃ gas whose flow rate is controlled by the mass flow controller 241a together with the inert gas as the carrier gas into the processing chamber 201 is started. At this time, the opening degree of the APC valve 251 is adjusted to maintain the pressure in the processing chamber 201 within a range of 50 Pa to 1000 Pa, for example, 60 Pa. The supply flow rate of NH ₃ gas is set within a range of 1 slm to 10 slm, for example. The supply time of NH ₃ gas is, for example, in the range of 10 seconds to 30 seconds. When the predetermined time has elapsed, the valves 252a and 254a are closed, and the supply of NH ₃ gas is stopped.

The NH ₃ gas supplied into the processing chamber 201 is supplied to the Ti-containing layer on the wafer 200 and exhausted from the exhaust pipe 231. At this time, the gas present in the processing chamber 201 is only an inert gas such as NH ₃ gas and N ₂ gas, and there is no Ti-containing gas such as TiCl ₄ gas. Therefore, the NH ₃ gas causes a surface reaction with the Ti-containing layer on the wafer 200 without causing a gas phase reaction. As a result, the Ti-containing layer is nitrided, and a TiN layer of less than one atomic layer to several atomic layers is formed on the HfO film.

During the NH ₃ gas supply, the inert gas supply pipe 234b connected to the Al-containing gas supply pipe 233b and the valves 254b and 254c of the inert gas supply pipe 234c connected to the Ti-containing gas supply pipe 233c are connected. When it is opened and an inert gas flows, the Al-containing gas supply pipe 233
It is possible to prevent NH ₃ gas from flowing into b and Ti-containing gas supply pipe 233c.

(Exhaust process S144a)
After the valve 252a is closed and the supply of NH ₃ gas into the processing chamber 201 is stopped, the APC valve 251 is opened and the pressure in the processing chamber 201 is evacuated to, for example, 20 Pa or less. Residual NH ₃ gas and reaction products are excluded. At this time, when an inert gas such as N ₂ is supplied into the processing chamber 201 from the inert gas supply pipes 234a, 234b, and 234c and purged, the effect of removing the residual gas from the processing chamber 201 can be further enhanced. it can. After a predetermined time has elapsed, the valves 234a, 234b, and 234c are closed, and the exhaust process S144a is terminated.

As described above, in the present embodiment, TiCl ₄ gas and NH ₃ gas are supplied independently, and the exhaust steps S142a and S144a are further performed between the supply steps, whereby the TiCl ₄ gas and the NH ₃ gas are supplied. And do not mix with each other.

(Predetermined number of execution steps S145a)
The above-described steps S141a to S144a are set as one cycle, and this cycle is performed a predetermined number of times, thereby laminating one or more TiN layers on the HfO film formed in advance on the wafer 200, and a predetermined film thickness, for example, 0.8 nm. A TiN film as a third nitride film having a thickness of 15 nm or less is formed. FIG. 5 shows an example in which the number of cycles is p. The horizontal axis of FIG. 5 shows the elapsed time, and the vertical axis shows the supply timing of each gas. The thickness of the TiN film as the third nitride film can be controlled by adjusting the number of executions (numerical value of p) of the steps S141a to S144a.

(Fourth nitride film forming step)
(Aluminum-containing gas supply step S141b)
In the aluminum-containing gas supply step S141b, TMA gas as an Al-containing gas is supplied into the processing chamber 201. Specifically, by closing the valve 256b and opening the valve 253b, supply of the TMA gas vaporized in the TMA container 261b together with the carrier gas into the processing chamber 201 is started. At this time, the opening degree of the APC valve 251 is adjusted to maintain the pressure in the processing chamber 201 within the range of 20 Pa to 50 Pa, for example, 30 Pa. The supply flow rate of the TMA gas is set, for example, in the range of 1.0 g / min to 2.0 g / min. The TMA gas supply time is, for example, in the range of 3 seconds to 10 seconds. When the predetermined time has elapsed, the valve 253b is closed and the valve 256b is opened, and the supply of TMA gas is stopped.

The TMA gas supplied into the processing chamber 201 is supplied to the TiN film on the wafer 200 and exhausted from the exhaust pipe 231. At this time, the gas present in the processing chamber 201 is only an inert gas such as TMA gas and N ₂ gas, and there is no nitrogen-containing gas such as NH ₃ gas. Therefore, the TMA gas causes a chemical adsorption (surface reaction) with a surface portion such as a TiN film formed on the HfO film without causing a gas phase reaction, thereby forming an adsorption layer or an Al layer of TMA molecules. The TMA molecule adsorption layer includes a continuous adsorption layer of TMA molecules and a discontinuous adsorption layer. The Al layer includes not only a continuous layer composed of Al but also an Al thin film formed by overlapping these layers. In the following, all of these are also referred to as Al-containing layers.

  During the supply of TMA gas, the valves 254a and 254c of the inert gas supply pipe 234a connected to the nitrogen-containing gas supply pipe 232a and the inert gas supply pipe 234c connected to the Ti-containing gas supply pipe 233c are opened. By flowing the inert gas, it is possible to prevent the TMA gas from flowing into the nitrogen-containing gas supply pipe 232a and the Ti-containing gas supply pipe 233c.

(Exhaust process S142b)
After closing the valve 253b and stopping the supply of the TMA gas into the processing chamber 201, the TMA gas remaining in the processing chamber 201 is exhausted and processed in the same procedure as the exhaust process S142a described above. The inside of the chamber 201 is purged.

(Nitrogen-containing gas supply step S143b)
In the nitrogen-containing gas supply step S143b, NH ₃ gas as a nitrogen-containing gas is supplied into the processing chamber 201 by the same procedure and processing conditions as the above-described nitrogen-containing gas supply step S143a. At this time, an inert gas may be flowed into the processing chamber 201 from another gas supply system.

The NH ₃ gas supplied into the processing chamber 201 is supplied to the Al-containing layer on the wafer 200 and exhausted from the exhaust pipe 231. At this time, the gas present in the processing chamber 201 is only an inert gas such as NH ₃ gas and N ₂ gas, and there is no Al-containing gas such as TMA gas. Accordingly, the NH ₃ gas causes a surface reaction with the Al-containing layer on the wafer 200 without causing a gas phase reaction. As a result, the Al-containing layer is nitrided, and an AlN layer of less than one atomic layer to several atomic layers is formed on the TiN film.

(Exhaust process S144b)
After the valve 252a is closed and the supply of the NH ₃ gas into the processing chamber 201 is stopped, the NH ₃ gas and reaction products remaining in the processing chamber 201 are processed in the same procedure as the exhaust process S144a described above. Etc., and the inside of the processing chamber 201 is purged.

As described above, in this embodiment, TMA gas and NH ₃ gas are supplied independently, and the exhaust steps S142b and S144b are performed between the supply steps, whereby the TMA gas and the NH ₃ gas are obtained. Try not to mix with each other.

(Predetermined number of execution steps S145b)
By performing the above steps S141b to S144b as one cycle and performing this cycle a predetermined number of times, one or more AlN layers are stacked on the TiN film as the third nitride film, and a predetermined film thickness, for example, 0.2 nm to 1 nm An AlN film as a fourth nitride film having the following thickness is formed. FIG. 5 shows an example in which the number of cycles is q. The thickness of the AlN film as the fourth nitride film can be controlled by adjusting the number of executions of the cycle from step S141b to step S144b (numerical value of q).

  When forming the AlN film as the fourth nitride film, if the processing temperature (the temperature of the wafer 200) is too high, the in-plane film thickness distribution of the AlN film becomes non-uniform. However, in this embodiment, since the processing temperature is set to 350 ° C. or less as described above, the uniformity of the in-plane film thickness distribution of the AlN film can be improved. As a result, the in-plane uniformity of the thickness of the TiAlN film as the first nitride film and the uniformity of the Al concentration distribution in the TiAlN film can be improved.

(Predetermined number of execution steps S150)
In the predetermined number of times execution step S150, the third nitride film formation step and the fourth nitride film formation step described above are set as one set, and this set is executed a predetermined number of times, so that the HfO film previously formed on the wafer 200 is A TiAlN film as a first nitride film having a predetermined film thickness, for example, a thickness of 1 nm to 16 nm, that is, a stacked film of a TiN film as a third nitride film and an AlN film as a fourth nitride film is formed. The thickness of the TiAlN film as the first nitride film can be controlled by adjusting the number of executions of the set of the third nitride film forming process and the fourth nitride film forming process.

  By forming the first nitride film constituting the lower layer (diffusion suppression film) of the gate electrode with a TiAlN film instead of a TiN film, the characteristics of a semiconductor device such as a CMOS can be improved. For example, in the pMOS transistor, the work function of the first nitride film in contact with the gate insulating film is preferably large, and in the nMOS transistor, the work function of the first nitride film in contact with the gate insulating film is preferably small. In this embodiment, the first nitride film in contact with the gate insulating film is formed of a TiAlN film, and the work function of the first nitride film is controlled by controlling the composition ratio of Ti and Al in the TiAlN film. be able to. A gate electrode having desired characteristics can be provided for each of the pMOS transistor and the nMOS transistor having different required characteristics. That is, since Al added to TiN has the property of lowering the work function, a TiAlN film (Ti-rich TiAlN film) with a relatively high Ti composition ratio relative to Al is formed as the first nitride film. A gate electrode suitable for a pMOS transistor can be provided, and by forming a TiAlN film (Al-rich TiAlN film) having a relatively high Al composition ratio with respect to Ti as a first nitride film, the nMOS transistor A suitable gate electrode can be provided.

  The composition ratio of Ti and Al in the TiAlN film can be easily controlled by adjusting the ratio between the thickness of the TiN film as the third nitride film and the thickness of the AlN film as the fourth nitride film. it can. That is, the predetermined number of executions in the third nitride film formation step S145a (p times in FIG. 5) and the predetermined number of executions in the fourth nitride film formation step S145b (q times in FIG. 5). By adjusting the ratio, the composition ratio between Ti and Al can be easily controlled. For example, when p> q, the thickness of the TiN film formed per third nitride film forming step is larger than the thickness of the AlN film formed per fourth nitride film forming step. Then, a TiAlN film (Ti-rich TiAlN film) in which the composition ratio of Ti to Al is relatively increased can be formed. Further, when p <q, the thickness of the TiN film formed per third nitride film forming step is smaller than the thickness of the AlN film formed per fourth nitride film forming step. Then, a TiAlN film (Al-rich TiAlN film) in which the composition ratio of Al to Ti is relatively increased can be formed.

  Note that the upper limit of the composition ratio of Al to Ti is preferably about 50%. Thereby, the resistivity of the gate electrode can be kept low.

  In the above description, when the TiAlN film as the first nitride film is formed, the third nitride film forming process is started, but the fourth nitride film forming process may be started. In other words, an AlN film as a fourth nitride film is first formed on the HfO film on the wafer 200, and then a TiN film as a third nitride film is formed. You may make it form.

(Second nitride film forming step)
Subsequently, a TiN film as a second nitride film (low resistance metal film) constituting the upper layer of the gate electrode is formed on the TiAlN film as the first nitride film (diffusion suppression film) constituting the lower layer of the gate electrode. . The formation of the TiN film as the second nitride film is continuously performed in the same processing chamber 201 without unloading the wafer 200 from the processing chamber 201.

  As a film formation method at this time, the ALD method is used instead of the CVD method. That is, as shown in FIG. 4, the titanium-containing gas supply step S161, the exhaust step S162, the nitrogen-containing gas supply step S163, and the exhaust step S164 are set as one cycle, and this cycle is performed a predetermined number of times (S165). For example, a TiN film as a second nitride film having a thickness of 5 nm to 30 nm is formed. FIG. 5 shows an example in which the number of cycles is r. The thickness of the TiN film as the second nitride film can be controlled by adjusting the number of executions of the cycle of step S161 to step S164 (numerical value of r).

  At this time, the titanium-containing gas supply step S161, the exhaust step S162, the nitrogen-containing gas supply step S163, and the exhaust step S164 are performed in the same procedure as the above-described third nitride film formation step (S141a to S144a). Also, the processing conditions can be the same as those in the third nitride film forming step, but the processing temperature (the temperature of the wafer 200) is in the range of 350 ° C. or higher and 550 ° C. or lower, for example, 550 ° C. It is preferable that

  By forming the TiN film as the second nitride film constituting the upper layer of the gate electrode by the ALD method instead of the CVD method, the characteristics of a semiconductor device such as a CMOS can be improved. That is, by forming the TiN film by the ALD method instead of the CVD method, the resistivity of the TiN film can be reduced, and the electrical characteristics of the gate electrode can be improved.

  In the present embodiment, the processing temperature when forming the TiN film as the second nitride film is within a range of 350 ° C. or higher and 550 ° C. or lower, and is increased to, for example, 550 ° C. The resistivity of the TiN film can be further reduced.

(Temperature drop step S170, normal pressure return step S180)
When the laminated film of the TiAlN film as the first nitride film and the TiN film as the second nitride film is formed, the power supply to the heater 207 is stopped, and the boat 217 and the wafer 200 are lowered to a predetermined temperature. While the temperature is lowered, the valves 254a, 254b, and 254c are kept open, and the supply of the purge gas into the processing chamber 201 is continued. Thereby, the inside of the processing chamber 201 is replaced with the purge gas, and the pressure in the processing chamber 201 is returned to the normal pressure.

(Substrate unloading step S190)
When the wafer 200 is lowered to a predetermined temperature and the inside of the processing chamber 201 is returned to normal pressure, the seal cap 219 is lowered by the boat elevator 115 by a procedure reverse to the procedure of the substrate loading step S110 described above, and the manifold The lower end of 209 is opened, and the boat 217 holding the processed wafer 200 is unloaded from the lower end of the manifold 209 to the outside of the reaction tube 203 (boat unloading). Thereafter, the processed wafer 200 is taken out from the boat 217 (wafer discharge). Note that when the boat 217 is carried out, it is preferable that the valves 254 a, 254 b, and 254 c are opened and the purge gas is continuously supplied into the processing chamber 201. Thus, the substrate processing process according to this embodiment is completed.

(5) Effects according to the present embodiment According to the present embodiment, the following one or more effects are achieved.

(A) According to the present embodiment, the first nitride film forming step and the second nitride film forming step are performed, and a laminated structure of a TiAlN film as the first nitride film and a TiN film as the second nitride film Are continuously formed in the same processing chamber 201. Accordingly, it is not necessary to form a stacked structure of gate electrodes in separate substrate processing apparatuses or processing chambers, and manufacturing costs can be reduced and productivity can be improved. In addition, by continuously forming the stacked structure of the gate electrodes in the same processing chamber 201 in which the degree of vacuum is maintained, the characteristics of the semiconductor device can be improved. That is, since the wafer 200 is not carried out of the processing chamber 201 during the formation of the gate electrode laminated structure, for example, exposure of the TiAlN film or the like constituting the lower layer of the gate electrode to the atmosphere can be avoided, and the oxidation of the gate electrode can be avoided. In addition, the entry of foreign matter into the gate electrode can be suppressed.

(B) According to the present embodiment, the first nitride film constituting the lower layer (diffusion suppression film) of the gate electrode is formed not by the TiN film but by the TiAlN film. Thereby, characteristics of a semiconductor device such as a CMOS can be improved. For example, in the pMOS transistor, the work function of the first nitride film in contact with the gate insulating film is preferably large, and in the nMOS transistor, the work function of the first nitride film in contact with the gate insulating film is preferably small. In this embodiment, the first nitride film in contact with the gate insulating film is formed of a TiAlN film, and the work function of the first nitride film is controlled by controlling the composition ratio of Ti and Al in the TiAlN film. be able to. A gate electrode having desired characteristics can be provided for each of the pMOS transistor and the nMOS transistor having different required characteristics. That is, since Al added to TiN has the property of lowering the work function, a TiAlN film (Ti-rich TiAlN film) with a relatively high Ti composition ratio relative to Al is formed as the first nitride film. A gate electrode suitable for a pMOS transistor can be provided, and by forming a TiAlN film (Al-rich TiAlN film) having a relatively high Al composition ratio with respect to Ti as a first nitride film, the nMOS transistor A suitable gate electrode can be provided.

(C) According to the present embodiment, the TiAlN film as the first nitride film is formed by performing the set a predetermined number of times with the third nitride film forming step and the fourth nitride film forming step as one set. doing. Thereby, the composition ratio of Ti and Al in the TiAlN film can be controlled easily and with high accuracy. That is, the predetermined number of executions in the third nitride film formation step S145a (p times in FIG. 5) and the predetermined number of executions in the fourth nitride film formation step S145b (q times in FIG. 5). The composition of Ti and Al in the TiAlN film is adjusted by adjusting the ratio of the thickness of the TiN film as the third nitride film and the thickness of the AlN film as the fourth nitride film. The ratio can be easily controlled. Thereby, the work function of the lower layer of the gate electrode can be controlled easily and with high accuracy.

(D) According to the present embodiment, the processing temperature (the temperature of the wafer 200) when forming the AlN film as the fourth nitride film is 350 ° C. or lower, for example, 350 ° C. Thereby, the in-plane uniformity of the film thickness of the AlN film as the fourth nitride film can be improved. As a result, the in-plane uniformity of the thickness of the TiAlN film as the first nitride film and the uniformity of the Al concentration distribution in the TiAlN film can be improved.

(E) According to the present embodiment, the TiN film as the second nitride film constituting the upper layer (low resistance metal film) of the gate electrode is formed not by the CVD method but by the ALD method. That is, the second nitride film having a predetermined thickness is obtained by performing this cycle, which includes the titanium-containing gas supply process S161, the exhaust process S162, the nitrogen-containing gas supply process S163, and the exhaust process S164, as a single cycle (S165). A TiN film is formed. Thereby, characteristics of a semiconductor device such as a CMOS can be improved. That is, by forming the TiN film by the ALD method instead of the CVD method, the resistivity of the TiN film can be reduced, and the electrical characteristics of the gate electrode can be improved.

(F) Further, according to the present embodiment, the processing temperature (temperature of the wafer 200) when forming the TiN film as the second nitride film is in the range of 350 ° C. or more and 550 ° C. or less, for example, 550 ℃. Thereby, the resistivity of the TiN film can be further reduced.

  FIG. 7 shows the resistivity of the TiN film (ALD-TiN film) formed by the ALD method and the resistivity of the TiN film (CVD-TiN film) formed by the CVD method, respectively. The horizontal axis of FIG. 7 shows the processing temperature (° C.) in each forming method, and the vertical axis shows the resistivity (μΩ · cm). In the figure, the mark ● indicates the resistivity of the ALD-TiN film, and the mark Δ indicates the resistivity of the CVD-TiN film.

As shown in FIG. 7, in a temperature range of at least 350 ° C. or more and 550 ° C. or less, the ALD-TiN film has a lower resistivity than the CVD-TiN film, and both are 200 μΩ · cm or less. It was resistivity. In addition, both CVD-TiN film and ALD-TiN film,
It can be seen that the resistivity decreases as the processing temperature is increased.

<Second Embodiment of the Present Invention>
Next, a substrate processing process according to the second embodiment of the present invention will be described. In the substrate processing step according to the present embodiment, the supply order of TiCl ₄ gas, TMA gas, and NH ₃ gas in the first nitride film forming step is different from that in the above-described embodiment. That is, instead of forming a TiAlN film in which a TiN film as a third nitride film and an AlN film as a fourth nitride film are alternately stacked, TiCl ₄ gas and TMA gas are sequentially supplied, and then collectively It differs from the above-described embodiment in that NH ₃ gas is supplied to form a TiAlN film in which Ti atoms and Al atoms are uniformly and continuously dispersed in the thickness direction. About another structure, it is the same as that of the above-mentioned embodiment. Hereinafter, mainly different points will be described.

(1) Substrate Processing Step The substrate processing step according to the present embodiment will be described below mainly using FIG. 8 and FIG. FIG. 8 is a flowchart illustrating the substrate processing process according to this embodiment, and FIG. 9 is a gas supply timing chart of the substrate processing process according to this embodiment. The substrate processing process according to this embodiment is also performed using the processing furnace 202 of FIGS. The operation of each unit is controlled by the controller 280.

(Substrate carrying-in process S210-temperature rising process S230)
Each process of board | substrate carrying-in process S210, pressure reduction process S220, and temperature rising process S230 is performed in the procedure similar to each process S110-S130 of the above-mentioned embodiment.

(First nitride film forming step)
Subsequently, Steps S241a to S250 to be described later are performed to form a TiAlN film as a first nitride film on the HfO film formed in advance on the wafer 200. This will be described in detail below.

(Titanium-containing gas supply step S241a)
In the titanium-containing gas supply step S241a, TiCl ₄ gas as a Ti-containing gas is supplied into the processing chamber 201 in the same procedure and processing conditions as the titanium-containing gas supply step S141a according to the above-described embodiment. As a result, a Ti-containing layer is formed on the HfO film previously formed on the wafer 200.

(Exhaust process S242a)
The atmosphere in the processing chamber 201 is exhausted and the inside of the processing chamber 201 is purged in the same procedure as the exhausting step S142a according to the above-described embodiment.

(Aluminum-containing gas supply step S241b)
A TMA gas as an Al-containing gas is supplied into the processing chamber 201 by the same procedure and processing conditions as in the aluminum-containing gas supply step S141b according to the above-described embodiment. Thereby, an Al-containing layer is formed on the Ti-containing layer. Alternatively, a layer in which a Ti-containing layer and an Al-containing layer are mixed is formed. In the following, all of these are also referred to as TiAl-containing layers.

(Exhaust process S242b)
The atmosphere in the processing chamber 201 is exhausted and the inside of the processing chamber 201 is purged in the same procedure as the exhausting step S142b according to the above-described embodiment.

(Nitrogen-containing gas supply step S241c)
In the nitrogen-containing gas supply step S241c, NH ₃ gas as a nitrogen-containing gas is supplied into the processing chamber 201 in the same procedure and processing conditions as the nitrogen-containing gas supply steps S143a and S143b according to the above-described embodiment. As a result, the TiAl-containing layer is nitrided to form a TiAlN layer.

(Exhaust process S242c)
The atmosphere in the processing chamber 201 is evacuated and the inside of the processing chamber 201 is purged in the same procedure as the exhaust steps S144a and S144b according to the above-described embodiment.

As described above, in the present embodiment, TiCl ₄ gas, TMA gas, and NH ₃ gas are independently supplied, and the exhaust steps S242a, S242b, and S242c are further performed between the supply steps, whereby the TiCl ₄ gas is supplied. And TMA gas and NH ₃ gas are prevented from mixing with each other between different gases.

(Predetermined number of execution steps S250)
The above-described steps S241a to S242c are set as one cycle, and this cycle is performed a predetermined number of times to form a first nitride film having a predetermined film thickness, for example, a thickness of 2 nm to 10 nm on the HfO film formed on the wafer 200. A TiAlN film is formed. FIG. 9 shows an example in which the number of cycles is m. The thickness of the TiAlN film can be controlled by adjusting the number of execution times (numerical value of m) of the steps S241a to S242c.

In the above description, TiCl ₄ gas, TMA gas, and NH ₃ gas are supplied in this order. However, the supply order is not limited to this. For example, TMA gas, TiCl ₄ gas, and NH ₃ gas are supplied in the order of supply. Also good.

(Second nitride film forming step)
Subsequently, with the same procedure and processing conditions as the steps S161 to S164 according to the above-described embodiment, the steps S261 to S264 in FIG. 8 are set as one cycle and this cycle is performed a predetermined number of times (S265). A TiN film as a second nitride film having a predetermined film thickness, for example, a thickness of 5 nm to 30 nm is formed on the TiAlN film as the first nitride film. FIG. 9 shows an example in which the number of executions of the cycle is n. The thickness of the TiN film can be controlled by adjusting the number of executions (the value of n) of step S261 to step S264.

(Temperature lowering step S270 to substrate carrying out step S290)
The steps of the temperature lowering step S270, the normal pressure returning step S280, and the substrate carrying out step S290 are performed in the same procedure as the steps S170 to S190 of the above-described embodiment. Thus, the substrate processing process according to this embodiment is completed.

(2) Effects according to the present embodiment The same effects as those of the above-described embodiment are also achieved in the present embodiment.

(A) According to the present embodiment, TiCl ₄ gas, TMA gas, and NH ₃ gas are supplied a predetermined number of times in a predetermined order. Thus, the TiAlN film in which Ti atoms and Al atoms are uniformly and continuously dispersed in the thickness direction is not a TiAlN film in which TiN films and AlN films are alternately stacked as in the above-described embodiment. Can be formed. Whether the TiN film and the AlN film are alternately stacked to form a TiAlN film as in the above-described embodiment, or a more uniform and continuous TiAlN film as in the present embodiment, depends on the required characteristics of the semiconductor device. It can be appropriately selected according to the above.

(B) Further, according to the present embodiment, the supply order of each gas is TiCl ₄ gas, TMA gas, NH
The order is ₃ gases, or TMA gas, TiCl ₄ gas, NH ₃ gas. Accordingly, the Ti-containing layer and the Al-containing layer can be simultaneously nitrided in one nitrogen-containing gas supply step S241c, and the number of gas supply steps can be reduced. Therefore, productivity can be further improved.

(C) Further, according to the present embodiment, the composition ratio of Ti and Al in the TiAlN film is freely controlled by controlling at least one of the supply time, supply flow rate, and supply frequency of the TiCl ₄ gas and the TMA gas. Can be controlled. As a result, the characteristics of the semiconductor device can be further improved.

  Below, the control method of the composition ratio of Ti and Al is demonstrated as a modification of this embodiment. Note that these methods are not limited to being used alone, but can be arbitrarily combined.

(Modification 1)
Modification 1 of the present embodiment will be described with reference to FIG. FIG. 10 is a gas supply timing chart of the substrate processing process according to the present modification, where (a) is a diagram in which the supply time of the Ti-containing gas is extended, and (b) is a graph in which the supply time of the Al-containing gas is extended. It is a figure.

  As shown in FIG. 10A, if the supply time of the Ti-containing gas in the first nitride film forming step is relatively longer than the supply time of the Al-containing gas, the composition ratio of Ti to Al in the TiAlN film Can be relatively increased. Further, as shown in FIG. 10B, if the supply time of the Al-containing gas is relatively longer than the supply time of the Ti-containing gas in the first nitride film forming step, the Al content relative to Ti in the TiAlN film is increased. The composition ratio can be relatively increased.

(Modification 2)
A second modification of the present embodiment will be described with reference to FIG. FIG. 11 is a gas supply timing chart of the substrate processing step according to the present modification, where (a) is a diagram in which the supply flow rate of the Ti-containing gas is increased, and (b) is an increase in the supply flow rate of the Al-containing gas. It is a figure.

  As shown in FIG. 11A, if the supply flow rate of the Ti-containing gas in the first nitride film forming step is relatively larger than the supply flow rate of the Al-containing gas, the composition ratio of Ti to Al in the TiAlN film. Can be relatively increased. In addition, as shown in FIG. 11B, if the supply flow rate of the Al-containing gas is relatively higher than the supply flow rate of the Ti-containing gas in the first nitride film forming step, the Al content relative to Ti in the TiAlN film is increased. The composition ratio can be relatively increased.

When the gas supply is a bubbling method as in this embodiment, the supply flow rate of each gas can be controlled by, for example, a heater provided in the liquid source container for each gas. That is, if the temperature in the TiCl ₄ container 261c and the TMA container 261b is increased, the volatilization amount of the liquid source can be increased and the gas supply flow rate into the processing chamber 201 can be increased. Moreover, if the temperature in the TiCl ₄ container 261c and the TMA container 261b is lowered, the volatilization amount of the liquid raw material can be reduced and the gas supply flow rate into the processing chamber 201 can be reduced.

(Modification 3)
A third modification of the present embodiment will be described with reference to FIG. FIG. 12 is a gas supply timing chart of the substrate processing step according to the present modification, where (a) is a diagram in which the number of times of supply of the Al-containing gas is reduced, and (b) is a diagram in which the number of times of supply of the Ti-containing gas is reduced. It is a figure.

As shown in FIG. 12A, if the Ti-containing gas supply frequency in the first nitride film forming step is relatively larger than the Al-containing gas supply frequency, the composition ratio of Ti to Al in the TiAlN film. Can be relatively increased. Further, as shown in FIG. 12B, if the Ti-containing gas supply frequency in the first nitride film forming step is relatively smaller than the Al-containing gas supply frequency, the Al content relative to Ti in the TiAlN film is reduced. The composition ratio can be relatively increased.

  12 (a) and 12 (b) show the case where the supply times of the Ti-containing gas and the Al-containing gas are 3 times: 1 time, 1 time: 3 times, respectively. Values and ratios can be appropriately changed according to a desired composition ratio.

<Third embodiment of the present invention>
Next, a substrate processing process according to the third embodiment of the present invention will be described. In the substrate processing step according to the present embodiment, a TiN film as a third nitride film is not formed by the ALD method, but TiCl ₄ gas and NH ₃ gas are supplied simultaneously and intermittently (pulse-like). It differs from the first embodiment in that it is formed by a pulse mode CVD method for exhausting. Further, the AlN film as the fourth nitride film is not formed by the ALD method, but is formed by the pulse mode CVD method in which TMA gas and NH ₃ gas are supplied simultaneously and intermittently (pulsed) and exhausted. The point is different from the first embodiment. The pulse mode CVD method is also applied to the formation of a TiN film as the second nitride film. About another structure, it is the same as that of 1st Embodiment. Hereinafter, mainly different points will be described.

(1) Substrate Processing Step The substrate processing step according to the present embodiment will be described below mainly using FIG. FIG. 13 is a gas supply timing chart of the substrate processing step according to the present embodiment. The substrate processing process according to this embodiment is also performed using the processing furnace 202 of FIGS. The operation of each unit is controlled by the controller 280.

(First nitride film forming step)
In this embodiment, after performing steps similar to steps S110 to S130 of the first embodiment, a third nitride film forming step and a fourth nitride film forming step, which will be described later, are sequentially performed to form on the wafer 200. A TiAlN film as a first nitride film is formed on the formed HfO film.

(Third nitride film forming step)
In the third nitride film forming step, the process of supplying and exhausting TiCl ₄ gas and NH ₃ gas simultaneously and intermittently (pulse-like) into the processing chamber 201 is performed a predetermined number of times, and TiN as the third nitride film is formed. A film is formed. The supply of TiCl ₄ gas and NH ₃ gas is performed similarly to the titanium-containing gas supply step S141a and the nitrogen-containing gas supply step S143a according to the first embodiment. Further, the processing conditions at this time can be set as follows, for example.
Processing chamber pressure: 10 Pa to 900 Pa, for example, 20 Pa,
Supply flow rate of TiCl ₄ gas: within a range of 0.1 g / min to 1.0 g / min,
NH ₃ gas supply flow rate: within a range of 0.1 slm to 15 slm,
Gas supply time: Within 2 to 90 seconds

(Fourth nitride film forming step)
In the fourth nitride film forming step, a process of supplying and exhausting TMA gas and NH ₃ gas simultaneously and intermittently (pulse-like) into the processing chamber 201 is performed a predetermined number of times, and an AlN film as a fourth nitride film Form. The supply of the TMA gas and the NH ₃ gas is performed in the same manner as the aluminum-containing gas supply step S141b and the nitrogen-containing gas supply step S143b according to the first embodiment. Further, the processing conditions at this time can be set as follows, for example.
Processing chamber pressure: 10 Pa to 900 Pa, for example, 20 Pa,
TMA gas supply flow rate: within a range of 0.1 g / min to 1.0 g / min,
NH ₃ gas supply flow rate: within a range of 0.1 slm to 15 slm,
Gas supply time: Within 2 to 90 seconds

  In the third and fourth nitride film forming steps, “supplying each gas simultaneously” means that the time during which each gas is supplied overlaps even a little. That is, in addition to the case where the timing of one or both of the supply start and stop of each gas coincides, the case where the timings of the start and stop of supply of each gas are shifted are also included.

(Predetermined number of execution steps S250)
By carrying out this set a predetermined number of times with the above-described third nitride film forming step and fourth nitride film forming step as a set, a TiAlN film having a predetermined film thickness is formed on the HfO film previously formed on the wafer 200. Form.

(Second nitride film forming step)
A TiN film as the second nitride film is formed on the TiAlN film as the first nitride film by the same procedure and processing conditions as the third nitride film forming step according to the present embodiment described above.

  Thereafter, the same steps as the temperature lowering step S170, the normal pressure return step S180, and the substrate carry-out step S190 of the first embodiment are sequentially performed, and the substrate processing step according to the present embodiment is completed.

(2) Effects according to the present embodiment As described above, the present embodiment also has the same effects as the above-described embodiments.

(A) According to the present embodiment, the third nitride film forming step of supplying and exhausting TiCl ₄ gas and NH ₃ gas simultaneously and intermittently (pulse-like) into the processing chamber 201, and the processing chamber The fourth nitride film forming step of supplying and exhausting TMA gas and NH ₃ gas simultaneously and intermittently (pulse-like) into the 201 is performed as a set, and this set is performed a predetermined number of times, thereby performing the first nitridation. A TiAlN film is formed as a film. In this way, both the advantages of the CVD method and the ALD method can be obtained by supplying and exhausting each gas simultaneously and intermittently (pulse-like).

  For example, in a general CVD method, a plurality of types of gases including a plurality of elements constituting a film to be formed are supplied simultaneously and continuously to a substrate. In this case, a relatively high deposition rate can be obtained as compared with the ALD method. However, it has been difficult to obtain highly accurate film thickness controllability and good step coverage as in the ALD method.

  In this embodiment, each gas is supplied simultaneously and intermittently (in a pulse manner) and exhausted, thereby improving the film formation speed while taking advantage of the ALD method with excellent film thickness controllability and step coverage. It becomes possible to make it.

(B) Further, according to the present embodiment, TiCl ₄ gas and NH ₃ gas or TMA gas and NH ₃ gas are supplied at the same time without being supplied individually, so that the number of gas supply steps can be reduced. Can do. Therefore, productivity can be further improved.

(Modification)
In the third nitride film forming process and the fourth nitride film forming process of the present embodiment, the process of supplying and exhausting a plurality of types of gases simultaneously and intermittently (pulsed) was performed several times each. The present invention is not limited to such a form. For example, as illustrated in FIG. 14, in the third nitride film forming process and the fourth nitride film forming process, a process of supplying and exhausting a plurality of gases simultaneously and intermittently (pulse-like) is performed once each. You may make it implement. This modification is obtained by combining the second embodiment and the third embodiment.

<Fourth embodiment of the present invention>
Next, a substrate processing process according to the fourth embodiment of the present invention will be described. In the substrate processing process according to the present embodiment, as shown in FIG. 15, two kinds of gases are supplied simultaneously and intermittently (pulse-like) in each of the third nitride film forming process and the fourth nitride film forming process. The third embodiment is different from the third embodiment in that it further includes a step of supplying and exhausting mainly only NH ₃ gas independently after exhausting. Further, the second nitride film forming step further includes a step of exhausting by supplying NH ₃ gas alone. About another structure, it is the same as that of 3rd Embodiment.

In this embodiment, since the process of supplying NH ₃ gas alone is further added, the Ti-containing layer and the Al-containing layer can be nitrided more reliably.

(Modification)
In the third nitride film forming step and the fourth nitride film forming step of the present embodiment, a process of supplying and exhausting a plurality of types of gases simultaneously and intermittently (pulse-like), and mainly NH ₃ gas alone are performed. The process of supplying and exhausting is defined as one cycle, and each cycle is performed a plurality of times. However, the present invention is not limited to this mode. For example, as illustrated in FIG. 16, in the third nitride film forming process and the fourth nitride film forming process, a process of supplying and exhausting plural kinds of gases simultaneously and intermittently (pulse-like) once each. You may make it implement. This modification is obtained by combining the modification of the third embodiment and the fourth embodiment.

15 and 16 show an example in which the NH ₃ gas is supplied independently each time the process of supplying and exhausting plural kinds of gases simultaneously and intermittently (pulse-like) is executed. However, it is possible to arbitrarily select the timing and the number of times of supplying the NH ₃ gas independently.

<Fifth embodiment of the present invention>
Next, a substrate processing process according to the fifth embodiment of the present invention will be described. As shown in FIG. 17, the substrate processing process according to the present embodiment is different from the fourth embodiment in that NH ₃ gas is not supplied intermittently (in a pulse manner) and is continuously supplied at a constant flow rate. . That is, in the third nitride film forming step according to the present embodiment, the step of supplying the TiCl ₄ gas intermittently (in a pulse manner) into the processing chamber 201 while continuously supplying the NH ₃ gas into the processing chamber 201. Is performed a predetermined number of times. In the fourth nitride film forming step according to the present embodiment, a step of supplying TMA gas intermittently (in a pulse manner) into the processing chamber 201 while continuously supplying NH ₃ gas into the processing chamber 201. Perform a predetermined number of times. Further, in the second nitride film forming step, the step of supplying the TiCl ₄ gas intermittently (in a pulse manner) into the processing chamber 201 while supplying the NH ₃ gas continuously into the processing chamber 201 is performed a predetermined number of times. . About another structure, it is the same as that of 4th Embodiment.

In this embodiment, since NH ₃ gas is continuously supplied, the nitriding of the Ti-containing layer and the Al-containing layer can be performed more reliably.

In the present embodiment, the flow of NH ₃ gas is always formed in the processing chamber 201, so that the diffusion of TiCl ₄ gas and TMA gas in the processing chamber 201 can be promoted. In addition, the flow of TiCl ₄ gas and TMA gas in the processing chamber 201 can be stabilized. In addition, since the NH ₃ gas is continuously supplied, the pressure fluctuation in the processing chamber 201 can be suppressed, the processing characteristics of the wafer 200 can be stabilized, and foreign matter ( Particles) can be suppressed.

In this embodiment, since NH ₃ gas is continuously supplied, the number of valve opening / closing operations can be reduced, and the control of the substrate processing apparatus can be simplified. Moreover, consumption of the valve can be suppressed.

(Modification)
In the third nitride film forming process and the fourth nitride film forming process of the present embodiment, the process of supplying and exhausting TiCl ₄ gas or TMA gas intermittently (in a pulse manner) was performed several times. The present invention is not limited to such a form. For example, as illustrated in FIG. 18, in the third nitride film forming process and the fourth nitride film forming process, the TiCl ₄ gas or the TMA gas is intermittently (pulsed) and exhausted once. You may make it implement. This modification is obtained by combining the fourth embodiment and the fifth embodiment.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, It can change variously in the range which does not deviate from the summary.

  For example, in the above-described embodiment, the case where the CMOS gate electrode is formed by the laminated structure of the TiAlN film and the TiN film has been described, but the present invention is not limited to such a form. For example, upper and lower electrodes of MIM (Metal-Insulator-Metal) capacitors provided in semiconductor devices such as DRAM (Dynamic Random Access Memory) and contact electrode barrier metal films that require both oxidation resistance and low resistance are formed. Even in this case, the present invention can be preferably applied.

  The MIM capacitor includes upper and lower electrodes that sandwich a capacitor insulating film made of, for example, an HfO film. When the present invention is applied to the formation of the upper and lower electrodes, a TiN film as a second nitride film and a TiAlN film as a first nitride film are laminated in this order on a substrate to form a lower electrode, or a capacitor insulating film An upper electrode can be formed by laminating a TiAlN film as a first nitride film and a TiN film as a second nitride film in this order. In any case, it is preferable to form a TiAlN film on the capacitor insulating film side in order to improve the bonding state at the interface of the capacitor insulating film that affects the device characteristics.

In the above embodiments, descriptions have been given of the case using a TiCl ₄ gas as a Ti-containing gas, a Ti-containing gas is not limited to this, for example, TDMAT (tetrakis-dimethylamino titanium: Ti _{(NMe 2) 4)} gas, TDEAT (tetrakisdiethylaminotitanium: Ti (NEt ₂ ) ₄ ) gas or the like can be used.

In the above-described embodiment, the case where the TMA gas is used as the Al-containing gas has been described. However, the Al-containing gas is not limited thereto, and for example, aluminum trichloride (AlCl ₃ ) or the like can be used.

In the above-described embodiment, the case where NH ₃ gas is used as the nitrogen-containing gas (nitriding agent) has been described. However, the nitrogen-containing gas is not limited to this, and for example, nitrogen (N ₂ ) gas or nitrogen trifluoride ( NF ₃ ) gas, hydrazine (N ₂ H ₄ ) gas, or the like can be used. Note that the nitrogen-containing gas may be plasma-excited and supplied into the processing chamber 201.

  In the above-described embodiment, the method of supplying each gas is the same in the first nitride film formation step and the second nitride film formation, but in the first nitride film formation step and the second nitride film formation step. Different supply methods or the like may be used, and any of the methods exemplified in the above-described embodiment and its modifications may be arbitrarily combined.

Further, in each of the above-described embodiments, after one or both of the first nitride film forming process and the second nitride film forming process, an annealing process for heating the nitride film formed on the substrate is performed. Also good. In the annealing treatment, for example, the pressure in the processing chamber is in a range of 50 Pa to 1000 Pa, for example, maintained at 150 Pa, and NH ₃ gas is supplied in a range of 1 slm to 91 slm, for example, 1 minute to 10 minutes. It can be carried out within the range. The processing temperature can be adjusted to the process of forming each film, for example. In this specification, if a series of processes are performed in the same processing chamber, the TiAlN film and the TiN film are continuously formed even when other processes such as annealing are performed on the way. It expresses that it is forming.

The gas supplied into the processing chamber during the annealing treatment includes NH ₃ gas, nitrogen-containing gas such as N ₂ gas and monomethylhydrazine (CH ₆ N ₂ ) gas, and hydrogen (H) such as H ₂ gas. An inert gas such as gas, Ar gas, or He gas can be used.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

(Appendix 1)
One embodiment of the present invention provides:
A substrate carrying-in process for carrying the substrate into the processing chamber;
A first nitride film forming step of forming a titanium aluminum nitride film on the substrate;
A second nitride film forming step of forming a titanium nitride film on the substrate;
A substrate unloading step of unloading the substrate from the processing chamber,
In the method of manufacturing a semiconductor device, the first nitride film forming step and the second nitride film forming step are performed in the same processing chamber.

(Appendix 2)
Preferably,
In the first nitride film forming step,
A third nitride film forming step of forming a titanium nitride film on the substrate by supplying a titanium-containing gas and a nitrogen-containing gas to the substrate;
A fourth nitride film forming step of forming an aluminum nitride film on the substrate by supplying an aluminum-containing gas and a nitrogen-containing gas to the substrate, and alternately performing a predetermined number of times,
In the second nitride film forming step,
A titanium-containing gas and a nitrogen-containing gas are supplied to the substrate.

(Appendix 3)
Also preferably,
In the third nitride film forming step,
To prevent the titanium-containing gas and nitrogen-containing gas from mixing with each other
Supplying and exhausting a titanium-containing gas into the processing chamber;
Alternately performing a process of supplying and exhausting a nitrogen-containing gas into the processing chamber a predetermined number of times,
In the fourth nitride film forming step,
To prevent the aluminum-containing gas and nitrogen-containing gas from mixing with each other,
Supplying and exhausting an aluminum-containing gas into the processing chamber;
The process of supplying and exhausting the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 4)
Also preferably,
In the third nitride film forming step,
A process of supplying and exhausting a titanium-containing gas and a nitrogen-containing gas simultaneously into the processing chamber is performed a predetermined number of times,
In the fourth nitride film forming step,
A step of supplying and exhausting an aluminum-containing gas and a nitrogen-containing gas simultaneously into the processing chamber is performed a predetermined number of times.

(Appendix 5)
Also preferably,
In the third nitride film forming step,
Supplying and exhausting a titanium-containing gas and a nitrogen-containing gas simultaneously into the processing chamber;
Alternately performing a process of supplying and exhausting a nitrogen-containing gas into the processing chamber a predetermined number of times,
In the fourth nitride film forming step,
A step of simultaneously supplying and exhausting an aluminum-containing gas and a nitrogen-containing gas into the processing chamber;
The process of supplying and exhausting the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 6)
Also preferably,
In the third nitride film forming step,
While continuously supplying the nitrogen-containing gas into the processing chamber, the step of intermittently supplying the titanium-containing gas into the processing chamber is performed a predetermined number of times,
In the fourth nitride film forming step,
The step of intermittently supplying the aluminum-containing gas into the processing chamber is performed a predetermined number of times while continuously supplying the nitrogen-containing gas into the processing chamber.

(Appendix 7)
Preferably,
In the first nitride film forming step,
Supplying the substrate with a titanium-containing gas, an aluminum-containing gas and a nitrogen-containing gas a predetermined number of times in a predetermined order;
In the second nitride film forming step,
A titanium-containing gas and a nitrogen-containing gas are supplied to the substrate.

(Appendix 8)
Also preferably,
In the first nitride film forming step,
Do not mix with each other between different gases.
Supplying and exhausting a titanium-containing gas into the processing chamber;
Supplying and exhausting an aluminum-containing gas into the processing chamber;
A process of supplying and exhausting a nitrogen-containing gas into the processing chamber is sequentially performed a predetermined number of times.

(Appendix 9)
Also preferably,
In the first nitride film forming step,
Supplying and exhausting a titanium-containing gas and a nitrogen-containing gas simultaneously into the processing chamber;
The step of simultaneously supplying and exhausting the aluminum-containing gas and the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 10)
Also preferably,
In the first nitride film forming step,
Supplying and exhausting a titanium-containing gas and a nitrogen-containing gas simultaneously into the processing chamber;
A step of simultaneously supplying and exhausting an aluminum-containing gas and a nitrogen-containing gas into the processing chamber;
A process of supplying and exhausting a nitrogen-containing gas into the processing chamber is sequentially performed a predetermined number of times.

(Appendix 11)
Also preferably,
In the first nitride film forming step,
While continuously supplying a nitrogen-containing gas into the processing chamber,
Intermittently supplying a titanium-containing gas into the processing chamber;
The step of intermittently supplying the aluminum-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 12)
Also preferably,
In the second nitride film forming step,
To prevent the titanium-containing gas and nitrogen-containing gas from mixing with each other
Supplying and exhausting a titanium-containing gas into the processing chamber;
The process of supplying and exhausting the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 13)
Also preferably,
In the second nitride film forming step,
A step of simultaneously supplying and exhausting a titanium-containing gas and a nitrogen-containing gas into the processing chamber is performed a predetermined number of times.

(Appendix 14)
Also preferably,
In the second nitride film forming step,
Supplying and exhausting a titanium-containing gas and a nitrogen-containing gas simultaneously into the processing chamber;
The process of supplying and exhausting the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times.

(Appendix 15)
Also preferably,
In the second nitride film forming step,
The step of intermittently supplying the titanium-containing gas into the processing chamber is performed a predetermined number of times while continuously supplying the nitrogen-containing gas into the processing chamber.

(Appendix 16)
Also preferably,
The titanium nitride film and the titanium aluminum nitride film are laminated in this order on the substrate to form a lower electrode of the capacitor.

(Appendix 17)
Also preferably,
On the insulating film formed on the substrate, the titanium aluminum nitride film and the titanium nitride film are laminated in this order to form an upper electrode of the capacitor.

(Appendix 18)
Also preferably,
In the first nitride film forming step and the second nitride film forming step, the substrate is heated at different processing temperatures.

(Appendix 19)
Also preferably,
The processing temperature in the first nitride film forming step is set to be equal to or lower than the processing temperature in the second nitride film forming step.

(Appendix 20)
Also preferably,
The processing temperature in the first nitride film forming step is 350 ° C. or lower,
The processing temperature in the second nitride film forming step is set to 350 ° C. or higher and 550 ° C. or lower.

(Appendix 21)
Another aspect of the present invention is:
A method of manufacturing a semiconductor device configured as a CMOS comprising a pMOS transistor and an nMOS transistor,
The gate electrode of the pMOS transistor is formed by laminating the titanium aluminum nitride film having a high composition ratio of titanium to aluminum and the titanium nitride film in this order,
In this method, the gate electrode of the nMOS transistor is formed by laminating the titanium aluminum nitride film having a high composition ratio of aluminum to titanium and the titanium nitride film in this order.

(Appendix 22)
Also preferably,
In the first nitride film forming step,
The composition ratio of titanium and aluminum in the titanium aluminum nitride film is controlled by controlling at least one of the supply time, supply flow rate, and supply frequency of the titanium-containing gas and aluminum-containing gas.

(Appendix 23)
Also preferably,
In the first nitride film forming step,
The composition ratio of titanium and aluminum in the titanium aluminum nitride film is controlled by controlling the film thickness ratio between the titanium nitride film and the aluminum nitride film in the titanium aluminum nitride film.

(Appendix 24)
Still another aspect of the present invention provides:
A processing chamber for accommodating the substrate;
A titanium-containing gas supply system for supplying a titanium-containing gas into the processing chamber;
An aluminum-containing gas supply system for supplying an aluminum-containing gas into the processing chamber;
A nitrogen-containing gas supply system for supplying a nitrogen-containing gas into the processing chamber;
An exhaust system for exhausting the atmosphere in the processing chamber;
A titanium-containing gas and a nitrogen-containing gas are supplied into the processing chamber containing the substrate to form a titanium nitride film on the substrate, and an aluminum-containing gas and a nitrogen-containing gas are supplied into the processing chamber to form an aluminum nitride film on the substrate. Forming a titanium aluminum nitride film by alternately performing the formation of the titanium nitride film and the formation of the aluminum nitride film a predetermined number of times,
The titanium-containing gas supply system, the aluminum-containing gas supply system, and the nitrogen-containing gas supply system so that a titanium-containing gas and a nitrogen-containing gas are supplied into the processing chamber in which the substrate is accommodated to form a titanium nitride film on the substrate. And a control system for controlling the exhaust system.

(Appendix 25)
Still another aspect of the present invention provides:
A semiconductor device formed by using any one of the semiconductor device manufacturing methods or the substrate processing apparatus.

(Appendix 26)
Still another aspect of the present invention provides:
A semiconductor device configured as a CMOS comprising a pMOS transistor and an nMOS transistor,
A gate electrode of the pMOS transistor in which a titanium aluminum nitride film having a high composition ratio of titanium to aluminum and a titanium nitride film are laminated in this order;
A semiconductor device comprising a titanium aluminum nitride film having a high composition ratio of aluminum to titanium and a gate electrode of the nMOS transistor in which a titanium nitride film is laminated in this order.

(Appendix 27)
Still another aspect of the present invention provides:
A titanium aluminum nitride film is formed on the gate insulating film formed on the substrate,
In this film forming method, a titanium nitride film is continuously formed on the titanium aluminum nitride film by an ALD method to form a gate electrode of a MOS transistor.

(Appendix 28)
Still another aspect of the present invention provides:
A titanium aluminum nitride film formed on the gate insulating film;
And a titanium nitride film formed on the titanium aluminum nitride film by an ALD method.

(Appendix 29)
Preferably,
A low resistance metal film is not formed on the titanium nitride film.

(Appendix 30)
Still another aspect of the present invention provides:
A titanium nitride film is formed on the substrate by ALD,
In this film forming method, a titanium aluminum nitride film is continuously formed on the titanium nitride film to form a lower electrode of the MIM capacitor.

(Appendix 31)
Still another aspect of the present invention provides:
A titanium aluminum nitride film is formed on the capacitor insulating film formed on the substrate,
In this film forming method, a titanium nitride film is continuously formed on the titanium aluminum nitride film by an ALD method to form an upper electrode of the MIM capacitor.

(Appendix 32)
Preferably,
In any one of the film forming methods,
Each of the films is formed using a titanium-containing gas, an aluminum-containing gas, and a nitrogen-containing gas.
The titanium-containing gas is tetrachlorotitanium gas, the aluminum-containing gas is trimethylaluminum gas, and the nitrogen-containing gas is ammonia gas.

(Appendix 33)
Also preferably,
In any one of the film forming methods,
The titanium aluminum nitride film and the titanium nitride film are formed at different temperatures.

(Appendix 34)
Also preferably,
In any one of the film forming methods,
The thickness of the titanium aluminum nitride film is 2 nm or less and / or the thickness of the titanium nitride film is 2 nm or more.

(Appendix 35)
Also preferably,
In any one of the film forming methods,
The titanium nitride film has a resistivity of 300 μΩ · cm or less.

(Appendix 36)
Still another aspect of the present invention provides:
A substrate processing apparatus used in any one of the film forming methods,
A substrate processing apparatus for processing a plurality of substrates simultaneously.

101 substrate processing apparatus 200 wafer (substrate)
201 processing chamber 280 controller

Claims (6)

A substrate carrying-in process for carrying the substrate into the processing chamber;
A first nitride film forming step of forming a titanium aluminum nitride film on the substrate;
A second nitride film forming step of forming a titanium nitride film on the titanium aluminum nitride film;
A substrate unloading step of unloading the substrate from the processing chamber,
Performing the first nitride film forming step and the second nitride film forming step in the same processing chamber ;
In the second nitride film forming step,
To prevent the titanium-containing gas and nitrogen-containing gas from mixing with each other
Supplying and exhausting the titanium-containing gas into the processing chamber;
And a step of supplying and exhausting the nitrogen-containing gas into the processing chamber alternately by a predetermined number of times . 2. The method of manufacturing a semiconductor device according to claim 1, wherein the substrate is heated at different processing temperatures in the first nitride film forming step and the second nitride film forming step. In the first nitride film forming step,
To prevent the titanium-containing gas and the nitrogen-containing gas from mixing with each other,
Supplying and exhausting the titanium-containing gas into the processing chamber;
Supplying and exhausting the nitrogen-containing gas into the processing chamber, and alternately performing a predetermined number of times; and
To prevent the aluminum-containing gas and the nitrogen-containing gas from mixing with each other,
Supplying and exhausting the aluminum-containing gas into the processing chamber;
Supplying and exhausting the nitrogen-containing gas into the processing chamber, and alternately performing a predetermined number of times; and
3. The method of manufacturing a semiconductor device according to claim 1, wherein the step is alternately performed a predetermined number of times. In the first nitride film forming step,
The titanium-containing gas, the aluminum-containing gas, and the nitrogen-containing gas are not mixed with each other.
Supplying and exhausting the titanium-containing gas into the processing chamber;
Supplying and exhausting the aluminum-containing gas into the processing chamber;
The method for manufacturing a semiconductor device according to claim 1, wherein the step of supplying and exhausting the nitrogen-containing gas into the processing chamber is alternately performed a predetermined number of times. A substrate carrying-in process for carrying the substrate into the processing chamber;
A first nitride film forming step of forming a titanium aluminum nitride film on the substrate;
A second nitride film forming step of forming a titanium nitride film on the titanium aluminum nitride film;
A substrate unloading step of unloading the substrate from the processing chamber,
Performing the first nitride film forming step and the second nitride film forming step in the same processing chamber;
In the second nitride film forming step,
A method of manufacturing a semiconductor device, wherein a titanium-containing gas is intermittently supplied and exhausted while a nitrogen-containing gas is continuously supplied into the processing chamber. A processing chamber for accommodating the substrate;
A titanium-containing gas supply system for supplying a titanium-containing gas into the processing chamber;
An aluminum-containing gas supply system for supplying an aluminum-containing gas into the processing chamber;
A nitrogen-containing gas supply system for supplying a nitrogen-containing gas into the processing chamber;
An exhaust system for exhausting the atmosphere in the processing chamber;
Titanium-containing gas into the processing chamber where the substrate is accommodated, an aluminum-containing gas and a nitrogen-containing gas by supplying to form a titanium aluminum nitride film on a substrate,
A process of supplying and exhausting a titanium-containing gas and supplying a nitrogen-containing gas so that the titanium-containing gas and the nitrogen-containing gas do not mix with each other in the processing chamber in which the substrate on which the titanium aluminum nitride film is formed is accommodated. And the process of exhausting in a predetermined number of times alternately to form a titanium nitride film on the titanium aluminum nitride film , the titanium-containing gas supply system, the aluminum-containing gas supply system, and the nitrogen-containing gas supply. And a control system for controlling the exhaust system.

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