JP6021977B2 - Substrate processing apparatus and semiconductor device manufacturing method - Google Patents

Description

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

In the ALD (Atomic Layer Deposition) method, for example, a raw material gas that is a raw material of a film and a reaction gas that reacts with the raw material gas are alternately supplied into a processing chamber, and thin films of one atomic layer are sequentially stacked. A predetermined film is formed on the substrate. Examples of the film formed by the ALD method include an aluminum oxide film (AlO film) formed by TMA (Trimethylaluminum) gas as a source gas and ozone (O ₃ ) gas as a reaction gas. . This aluminum oxide film functions as a high dielectric constant film (High-k film).

  The ALD method using TMA gas and ozone gas may be performed by setting the temperature in the processing chamber to about 200 ° C. to 400 ° C. However, at such processing temperatures, carbon (C) atoms and hydrogen (H) atoms constituting the source gas and reaction gas may remain as impurities in the film, resulting in a decrease in the dielectric constant of the film or leakage. In some cases, the function as a high dielectric constant film may be deteriorated due to an increase in current. Therefore, in order to reduce impurities in the film, the substrate processing may be performed by increasing the processing temperature to about 550 ° C., for example.

  However, when the processing temperature is increased, the inside of the nozzle is in a high temperature and high pressure state, and the raw material gas may be thermally decomposed in the nozzle. For example, when TMA gas is used as the source gas, a reaction product may be formed in the nozzle by a CVD (Chemical Vapor Deposition) reaction between aluminum (Al) atoms. Alternatively, reaction products and decomposition products of TMA gas may be deposited on the inner wall of the nozzle and the nozzle may be clogged. In addition, foreign substances generated as a result of such reaction products and decomposition products being peeled off from the inner wall of the nozzle may scatter in the processing chamber and adhere to the substrate, leading to a reduction in substrate processing quality.

  It is an object of the present invention to provide a substrate processing apparatus and a semiconductor device manufacturing method capable of suppressing the deposition of reaction products and decomposition products on the inner wall of a nozzle and suppressing the scattering of foreign substances into a processing chamber. And Another object of the present invention is to provide a semiconductor device provided with a high-quality thin film with little foreign matter mixed in by such a substrate processing apparatus and semiconductor device manufacturing method.

According to one aspect of the invention,
A processing chamber for stacking and accommodating a plurality of substrates;
A heating unit for heating the processing chamber;
A raw material gas supply unit for supplying a raw material gas into the processing chamber, wherein the raw material gas is not decomposed inside even when a temperature in the processing chamber is higher than a thermal decomposition temperature of the raw material gas. A raw material gas supply unit including a plurality of raw material gas nozzles having different lengths, which are disposed at predetermined positions and supply the raw material gas into the processing chamber;
A reaction gas supply unit for supplying a reaction gas into the processing chamber, the reaction gas supply unit being disposed in the processing chamber and having a reaction gas nozzle for supplying the reaction gas into the processing chamber;
Controlling the heating unit, the source gas supply unit, and the reaction gas supply unit to heat the processing chamber in which a plurality of substrates are stacked and accommodated, and the plurality of source gas nozzles having different lengths A process including supplying the source gas into the processing chamber and supplying the reaction gas from the reaction gas nozzle into the processing chamber is performed a predetermined number of times to form a film on the substrate. A control unit;
A substrate processing apparatus is provided.

  According to the present invention, it is possible to suppress reaction products and decomposition products from being deposited on the inner wall of the nozzle and to prevent foreign matter from scattering into the processing chamber. In addition, it is possible to suppress adhesion of foreign matter to the substrate and to suppress deterioration in substrate processing quality.

1 is a schematic configuration diagram of a substrate processing apparatus according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of the processing furnace with which the substrate processing apparatus which concerns on the 1st Embodiment of this invention is provided. It is a perspective view of the inner tube with which the substrate processing apparatus concerning a 1st embodiment of the present invention is provided, and shows the case where a gas exhaust port is a hole shape. It is a cross-sectional view of the process tube with which the substrate processing apparatus which concerns on the 1st Embodiment of this invention is provided, and the case where the nozzle accommodating part is provided in the inner tube is shown. It is a schematic diagram which illustrates the gas flow produced | generated in the process tube with which the substrate processing apparatus which concerns on the 1st Embodiment of this invention is provided. It is a flowchart figure of the substrate processing process which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows typically a mode that the aluminum oxide film is formed on a wafer. It is a figure which shows typically the mode of the gas supply which concerns on the 1st Embodiment of this invention. It is a timing chart figure concerning gas supply of a 1st embodiment of the present invention. It is a flowchart figure of the substrate processing process which concerns on the 2nd Embodiment of this invention. It is a figure which shows typically the mode of the raw material gas supply which concerns on the 2nd Embodiment of this invention, (a) When the flow velocity of raw material gas is made into the 1st flow velocity, (b) The flow velocity of raw material gas is 1st. The case where the second flow rate is larger than the flow rate of 1 is shown. It is a flowchart figure of the substrate processing process which concerns on the 2nd Embodiment of this invention. It is a figure which shows the TMA gas supply sequence which concerns on the 2nd Embodiment of this invention, and process conditions compared with the past. It is a flowchart figure of the substrate processing process which concerns on the 3rd Embodiment of this invention. It is a timing chart figure concerning gas supply of a 3rd embodiment of the present invention. It is a cross-sectional view of the process tube with which the substrate processing apparatus which concerns on other embodiment of this invention is provided, and the case where the nozzle accommodating part is not provided in the process chamber is shown. It is sectional drawing which shows typically the outline of the conventional substrate processing apparatus, and the raw material gas nozzle in which the reaction product and decomposition product deposited. It is a figure which shows the presence or absence of deposition of the decomposition product in a nozzle, and the film | membrane characteristic of an aluminum oxide film, contrasting the Example of the 2nd Embodiment of this invention, and a prior art example. It is explanatory drawing which shows the example of the raw material gas nozzle which the decomposition product accumulated inside. It is explanatory drawing which shows the example of the raw material gas nozzle which the decomposition product accumulated inside.

<First Embodiment of the Present Invention>
(1) Configuration of Substrate Processing Apparatus First, a configuration example of the substrate processing apparatus 101 according to the present embodiment will be described with reference to FIGS. 1 and 5.

  FIG. 1 is a schematic configuration diagram of a substrate processing apparatus 101 according to the present embodiment. FIG. 5 is a schematic view illustrating a gas flow generated in a process tube included in the substrate processing apparatus according to this embodiment.

  As shown in FIG. 1, the substrate processing apparatus 101 according to this embodiment includes a housing 111. In order to transfer the wafer 200 as a substrate made of silicon or the like into or 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 stage (substrate storage container delivery table) 114 is provided in front of the housing 111 (on the right side in the drawing). The cassette 110 is placed on the cassette stage 114 by an in-process transfer device (not shown), and is carried out of the casing 111 from the cassette stage 114.

  The cassette 110 is placed on the cassette stage 114 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 by the in-process transfer device. The cassette stage 114 rotates the cassette 110 90 degrees in the vertical direction toward the rear of the casing 111 to bring the wafer 200 in the cassette 110 into a horizontal posture, and the wafer loading / unloading port of the cassette 110 is positioned in the rear of the casing 111. It is configured to be able to face.

  A cassette shelf (substrate storage container mounting shelf) 105 is installed at a substantially central portion in the front-rear direction in the housing 111. 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. Further, a preliminary cassette shelf 107 is provided above the cassette stage 114, and is configured to store the cassette 110 in a preliminary manner.

  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 the cassette stage 114, the cassette shelf 105, 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.

  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 transfer jig) 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 is loaded into the boat (substrate holder) 217 described later (charging). Or the wafer 200 is unloaded (discharged) from the boat 217 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 (furnace port) is provided at the lower end of the processing furnace 202, and the opening is 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 boat elevator (substrate holder lifting mechanism) 115 is provided as a lifting mechanism that lifts and lowers the boat 217 and transports 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 disc-shaped seal cap 219 as a lid that supports the boat 217 vertically and hermetically closes the lower end of the processing furnace 202 when the boat 217 is raised by the boat elevator 115 is in a horizontal posture. Is provided.

  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. The detailed configuration of the boat 217 will be described later.

  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.

  Further, a clean unit (not shown) provided with a supply fan and a dustproof filter so as to supply clean air to the left end portion of the casing 111 opposite to the wafer transfer device elevator 125b and the boat elevator 115 side. Is installed. Clean air blown out from the clean unit (not shown) is configured to be sucked into an exhaust device (not shown) and exhausted to the outside of the casing 111 after circulating around the wafer transfer device 125a and the boat 217. ing.

(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 placed on the cassette stage 114 by an in-process transfer device (not shown) so that the wafer 200 is in a vertical posture and the wafer loading / unloading port of the cassette 110 faces upward. Thereafter, the cassette 110 is rotated 90 ° in the vertical direction 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.

  The cassette 110 is automatically transported to the designated shelf position of the cassette shelf 105 or the spare cassette shelf 107 by the cassette transporting device 118, delivered, temporarily stored, and then stored in the cassette shelf 105 or the spare cassette shelf. The sample is transferred from 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 (charged) into the boat 217 behind the transfer shelf 123. 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 lower end of the processing furnace 202 closed by the furnace port shutter 147 is opened by the furnace port shutter 147. Subsequently, when the seal cap 219 is raised by the boat elevator 115, the boat 217 holding the wafer 200 group is loaded into the processing furnace 202. After 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 discharged to the outside 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. FIG. 2 is a longitudinal sectional view of the processing furnace 202 provided in the substrate processing apparatus according to the present embodiment. FIG. 3 is a perspective view of the inner tube 204 provided in the substrate processing apparatus according to the present embodiment, and shows a case where the gas exhaust port 204a has a hole shape. FIG. 4 is a cross-sectional view of the process tube 205 provided in the substrate processing apparatus according to the present embodiment, and shows a case where the inner tube 204 is provided with a nozzle accommodating portion 201a.

(Processing room)
The processing furnace 202 according to this embodiment includes a process tube 205 as a reaction tube and a manifold 209. The process tube 205 includes an inner tube 204 that forms a processing chamber 201 that accommodates a plurality of wafers 200 stacked in a horizontal posture in an internal space, and an outer tube 203 that surrounds the inner tube 204. Each of the inner tube 204 and the outer tube 203 is made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a configuration in which the upper end is closed and the lower end is opened. . A part of the side wall of the inner tube 204 protrudes radially outward of the inner tube 204 (side wall side of the outer tube 203) from the side wall of the inner tube 204 along the direction (vertical direction) in which the wafer 200 is loaded. Yes. In the processing chamber 201, a space protruding outward in the radial direction of the inner tube 204 (side wall side of the outer tube 203) is configured as a nozzle housing portion 201a that houses a raw material gas nozzle 233a and a reaction gas nozzle 233b described later. The manifold 209 is made of, for example, a metal material such as SUS, and has a cylindrical shape with an open upper end and a lower end. The inner tube 204 and the outer tube 203 are supported vertically by the manifold 209 from the lower end side. The inner tube 204, the outer tube 203, and the manifold 209 are arranged concentrically with each other. The lower end (furnace port) of the manifold 209 is configured to be hermetically sealed by a seal cap 219 when the above-described boat elevator 115 is raised. A sealing member (not shown) such as an O-ring that hermetically seals the inner tube 204 is provided between the lower end of the manifold 209 and the seal cap 219.

  A boat 217 as a substrate holder is inserted into the inner tube 204 (inside the processing chamber 201) from below. The inner diameter of the inner tube 204 and the manifold 209 is configured to be larger than the maximum outer diameter of the boat 217 loaded with the wafers 200.

  The boat 217 includes a pair of end plates 217c at the top and bottom, and a plurality of (for example, three) support columns 217a that are vertically installed between the pair of end plates 217c. The end plate 217c and the support column 217a are made of a non-metallic material having heat resistance such as quartz or silicon carbide. A plurality of holding grooves 217b are formed in each column 217a so as to be arranged at equal intervals along the longitudinal direction of the column 217a. Each support column 217a is arranged so that the holding grooves 217b formed in each support column 217a face each other. By inserting the outer peripheral portion of the wafer 200 into each holding groove 217b, the plurality of wafers 200 are configured to be held in multiple stages with a predetermined gap (substrate pitch interval) in a substantially horizontal posture. The boat 217 is mounted on a heat insulating cap 218 that blocks heat conduction. The heat insulating cap 218 is supported from below by the rotating shaft 255. The rotation shaft 255 is provided so as to penetrate the center portion of the seal cap 219 while maintaining airtightness in the processing chamber 201. A rotation mechanism 267 that rotates the rotation shaft 255 is provided below the seal cap 219. By rotating the rotation shaft 255 by the rotation mechanism 267, the boat 217 on which a plurality of wafers 200 are mounted can be rotated while maintaining the airtightness in the processing chamber 201.

  On the outer periphery of the process tube 205 (outer tube 203), a heater 207 as a heating unit is provided concentrically with the process tube 205. The heater 207 has a cylindrical shape and is vertically installed by being supported by a heater base (not shown) as a holding plate. A heat insulating material 207 a is provided on the outer peripheral portion and the upper end of the heater 207. The heater 207 is configured to adjust the energization amount based on temperature information detected by a temperature sensor (not shown).

(Gas nozzle)
A raw material gas nozzle 233 a and a reaction gas nozzle 233 b are respectively disposed in the nozzle housing portion 201 a along the circumferential direction of the processing chamber 201. The source gas nozzle 233a and the reaction gas nozzle 233b are each configured in an L shape having a vertical portion and a horizontal portion. The raw material gas nozzle 233 a is configured as a short nozzle whose vertical portion is disposed at a predetermined position below a region where the wafer 200 is to be accommodated in the processing chamber 201. The reactive gas nozzle 233b is configured as a long nozzle whose vertical portion is disposed (extended) in the nozzle accommodating portion 201a along the stacking direction of the wafers 200. The horizontal portions of the source gas nozzle 233a and the reaction gas nozzle 233b are provided so as to penetrate the side wall of the manifold 209, respectively.

  As described above, the vertical portion of the source gas nozzle 233 a is configured to be disposed at a predetermined position below the planned storage area of the wafer 200 in the processing chamber 201. That is, the vertical portion of the source gas nozzle 233a is arranged so that the source gas is not decomposed inside even when the temperature of the region where the wafer 200 is to be accommodated in the processing chamber 201 is higher than the thermal decomposition temperature of the source gas. Is disposed at a predetermined position in the nozzle accommodating portion 201a below the planned accommodating region. For example, the vertical portion of the source gas nozzle 233a is disposed in the lower part of the processing chamber 201 and below the space surrounded by the heater 207. At the downstream end (upper end) of the source gas nozzle 233a, a source gas outlet 248a is provided so as to supply the source gas toward the upper part in the processing chamber 201. In this way, by configuring the source gas nozzle 233a as a short nozzle, it is possible to suppress the temperature rise inside the source gas nozzle 233a during the substrate processing, and it is difficult to cause thermal decomposition of the source gas inside the source gas nozzle 233a. it can.

  As described above, the vertical portion of the reactive gas nozzle 233b is configured to extend to the upper portion of the nozzle accommodating portion 201a so that the downstream end reaches the vicinity of the upper end of the boat 217. On the side surface of the vertical portion of the reactive gas nozzle 233b, a plurality of reactive gas ejection ports 248b are provided at positions (height positions) corresponding to the respective wafers 200 along the stacking direction (vertical direction) of the wafers 200. . Further, the opening diameter of the reactive gas outlet 248b can be adjusted as appropriate so as to optimize the flow rate distribution and velocity distribution of the reactive gas in the processing chamber 201, and may be the same from the lower part to the upper part. It may be gradually increased over time. As described above, by configuring the reactive gas nozzle 233b as a porous long nozzle, it becomes possible to make the supply amount of the reactive gas to the wafers 200 uniform among the wafers 200. In addition, when the reaction gas has the property of being easily pyrolyzed, the reaction gas nozzle 233b may be configured as a short nozzle similarly to the source gas nozzle 233a.

(Raw gas supply unit)
The downstream end of the source gas supply pipe 240a is connected to the upstream end of the horizontal portion of the source gas nozzle 233a protruding from the side wall of the manifold 209. Connected to the upstream end of the source gas supply pipe 240a is a TMA tank 260 that vaporizes liquid TMA as a liquid source and generates TMA gas as a source gas. Specifically, the upstream end of the source gas supply pipe 240a is disposed in the TMA tank 260 and above the liquid surface of the liquid TMA. The source gas supply pipe 240a is provided with an open / close valve 241a. By opening the opening / closing valve 241a, the TMA gas generated in the TMA tank 260 is supplied into the processing chamber 201 through the source gas nozzle 233a. The source gas supply pipe 240a is heated to, for example, 40 ° C. or higher and 130 ° C. or lower, and the manifold 209 is heated, for example, to 40 ° C. or higher and 150 ° C. or lower, so that the vaporized TMA gas is not reliquefied in the pipe. Has been.

  Connected to the upstream side of the TMA tank 260 is a downstream end of a carrier gas supply pipe 240 f that supplies a carrier gas such as an inert gas into the TMA tank 260. Specifically, the downstream end of the carrier gas supply pipe 240f is immersed in the liquid TMA in the TMA tank 260. The upstream end of the carrier gas supply pipe 240f is connected to a carrier gas supply source (not shown) that supplies an inert gas (carrier gas) such as argon gas (Ar gas). The carrier gas supply pipe 240f is provided with a flow rate controller (MFC) 242f and an opening / closing valve 241f in order from the upstream. By opening the opening / closing valve 241f, the carrier gas is supplied into the liquid TMA in the TMA tank 260, and the liquid TMA is bubbled. As the liquid TMA is bubbled, TMA gas is generated in the TMA tank 260. By opening the opening / closing valve 241a, the mixed gas containing the TMA gas generated in the TMA tank 260 and the carrier gas is supplied into the processing chamber 201 through the source gas supply pipe 240a and the source gas nozzle 233a. Has been. By supplying the carrier gas into the TMA tank 260, the liquid TMA can be vaporized, and the discharge of the TMA gas from the TMA tank 260 and the supply of the raw material gas into the processing chamber 201 can be promoted. The supply flow rate of the carrier gas into the TMA tank 260 (that is, the supply flow rate of the carrier gas into the processing chamber 201) is configured to be controllable by the flow rate controller 242f.

  Mainly, a raw material gas supply pipe 240a, a TMA tank 260, an opening / closing valve 241a, a carrier gas supply pipe 240f, a carrier gas supply source (not shown), a flow rate controller 242f, and an opening / closing valve 241f are inserted into the processing chamber 201 via the raw material gas nozzle 233a. A source gas supply unit for supplying source gas is configured.

(Reactive gas supply unit)
The downstream end of the reaction gas supply pipe 240b is connected to the upstream end of the horizontal portion of the reaction gas nozzle 233b protruding from the side wall of the manifold 209. An ozonizer 270 that generates ozone (O ₃ ) gas as a reaction gas (oxidant) is connected to the upstream end of the reaction gas supply pipe 240b. The reactive gas supply pipe 240b is provided with a flow rate controller (MFC) 242b and an opening / closing valve 241b in order from the upstream side. The downstream end of the oxygen gas supply pipe 240e is connected to the ozonizer 270. The upstream end of the oxygen gas supply pipe 240e is connected to an oxygen gas supply source (not shown) that supplies oxygen (O ₂ ) gas. The oxygen gas supply pipe 240e is provided with an opening / closing valve 241e. Oxygen gas is supplied to the ozonizer 270 by opening the opening / closing valve 241e, and ozone gas generated in the ozonizer 270 by opening the opening / closing valve 241b is supplied into the processing chamber 201 through the reaction gas supply pipe 240b. It is configured. Note that the supply flow rate of ozone gas into the processing chamber 201 can be controlled by the flow rate controller 242b.

  The processing chamber 201 is mainly connected to the processing chamber 201 through the reaction gas nozzle 233b by the reaction gas supply pipe 240b, the ozonizer 270, the flow rate controller (MFC) 242b, the open / close valve 241b, the oxygen gas supply pipe 240e, the oxygen gas supply source (not shown), and the open / close valve 241e. A reaction gas supply unit for supplying ozone gas is formed.

(Vent pipe)
The upstream end of the source gas vent pipe 240i is connected between the TMA tank 260 and the open / close valve 241a in the source gas supply pipe 240a. The downstream end of the source gas vent pipe 240i is connected to the downstream side of an exhaust pipe 231 described later (between an APC valve 231a and a vacuum pump 231b described later). The raw material gas vent pipe 240i is provided with an open / close valve 241i. By closing the opening / closing valve 241a and opening the opening / closing valve 241i, the supply of the source gas into the processing chamber 201 can be stopped while the generation of the source gas in the TMA tank 260 is continued. . Although a predetermined time is required to stably generate the source gas, the supply / stop of the source gas into the processing chamber 201 can be switched in a very short time by the switching operation of the opening / closing valve 241a and the opening / closing valve 241i. It is configured as follows.

  Similarly, the upstream end of the reaction gas vent pipe 240j is connected between the ozonizer 270 and the flow rate controller 242b in the reaction gas supply pipe 240b. The downstream end of the reaction gas vent pipe 240j is connected to the downstream side of the exhaust pipe 231 (between the APC valve 231a and the vacuum pump 231b). The reaction gas vent pipe 240j is provided with an open / close valve 241j and an ozone detoxifying device 242j in this order from upstream. By closing the opening / closing valve 241b and opening the opening / closing valve 241j, the supply of ozone gas into the processing chamber 201 can be stopped while the generation of ozone gas by the ozonizer 270 is continued. Although it takes a predetermined time to stably generate ozone gas, the supply / stop of ozone gas into the processing chamber 201 can be switched in a very short time by the switching operation of the opening / closing valve 241b and the opening / closing valve 241j. It is configured.

(Inert gas supply pipe)
The downstream end of the first inert gas supply pipe 240g is connected to the downstream side of the open / close valve 241a in the source gas supply pipe 240a. The first inert gas supply pipe 240g is provided with an inert gas supply source (not shown) for supplying an inert gas such as N ₂ gas, a flow rate controller (MFC) 242g, and an opening / closing valve 241g in order from the upstream side. . Similarly, the downstream end of the second inert gas supply pipe 240h is connected to the downstream side of the open / close valve 241b in the reaction gas supply pipe 240b. The second inert gas supply pipe 240h is provided with an inert gas supply source (not shown) for supplying an inert gas such as N ₂ gas, a flow rate controller (MFC) 242h, and an opening / closing valve 241h in order from the upstream side. .

  The inert gas supplied from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h functions as a dilution gas for diluting the source gas and the reaction gas and a purge gas for purging the inside of the processing chamber 201. Have.

  For example, by closing the opening / closing valve 241i and opening the opening / closing valve 241a and the opening / closing valve 241g, the mixed gas from the TMA tank 260 is diluted with the inert gas (diluted gas) from the first inert gas supply pipe 240g. It is configured so that it can be supplied into the processing chamber 201. Further, by opening the opening / closing valve 241b and the opening / closing valve 241h, the ozone gas from the ozonizer 270 is supplied into the processing chamber 201 while being diluted with the inert gas (diluted gas) from the second inert gas supply pipe 240h. Is configured to be possible. Thus, by diluting with the dilution gas, the concentration of the raw material gas and ozone gas supplied into the processing chamber 201 can be freely adjusted.

  Further, by closing the opening / closing valve 241a and opening the opening / closing valve 241i, the supply of the source gas into the processing chamber 201 is stopped while the generation of the source gas by the TMA tank 260 is continued, and the opening / closing valve 241g and the opening / closing valve 241h. Is opened so that the inert gas (purge gas) from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h can be supplied into the processing chamber 201. Similarly, by closing the opening / closing valve 241b and opening the opening / closing valve 241j, the supply of ozone gas into the processing chamber 201 is stopped while the generation of ozone gas by the ozonizer 270 is continued, and the opening / closing valve 241g and the opening / closing valve 241h are opened. Thus, the inert gas (purge gas) from the first inert gas supply pipe 240g and the second inert gas supply pipe 240h can be supplied into the processing chamber 201. In this way, by supplying the inert gas (purge gas) into the processing chamber 201, discharge of the source gas, ozone gas, and the like from the processing chamber 201 can be promoted.

(Gas exhaust part and gas exhaust port)
On the side wall of the inner tube 204, a gas exhaust part 204b constituting a part of the side wall of the inner tube 204 is provided along the direction in which the wafer 200 is stacked. The gas exhaust unit 204b is provided at a position facing the nozzle accommodating unit 201a with the wafer 200 accommodated in the processing chamber 201 interposed therebetween.

  A gas exhaust port 204a is opened in the gas exhaust unit 204b. The gas exhaust port 204a is opened at a position facing the reaction gas ejection port 248b with the wafer 200 in between (for example, a position opposite to the reaction gas ejection port 248b by about 180 degrees). The gas exhaust port 204 a according to the present embodiment has a hole shape and is opened at a position (height position) corresponding to each of the plurality of wafers 200. Accordingly, the space 203a sandwiched between the outer tube 203 and the inner tube 204 communicates with the processing chamber 201 through the gas exhaust port 204a. The hole diameter of the gas exhaust port 204a can be adjusted as appropriate so as to optimize the flow rate distribution and velocity distribution of the gas in the processing chamber 201. For example, the hole diameter may be the same from the lower part to the upper part. It may be gradually increased over time.

  Further, it is preferable that the height position of the lower end of the gas exhaust unit 204 b corresponds to the height position of the lowermost wafer 200 among the wafers 200 loaded into the processing chamber 201. Similarly, the height position of the upper end of the gas exhaust unit 204 b preferably corresponds to the height position of the uppermost wafer 200 among the wafers 200 loaded into the processing chamber 201. This is because if the gas exhaust unit 204b is provided even in a region where the wafer 200 does not exist, the gas that should flow between the wafers 200 may flow to a region where the wafer 200 does not exist.

(Exhaust unit)
The upstream end of the exhaust pipe 231 is connected to the side wall of the manifold 209. In order from the upstream side, the exhaust pipe 231 includes a pressure sensor 245 as a pressure detector, an APC (Auto Pressure Controller) valve 231a as a pressure regulator, a vacuum pump 231b as a vacuum exhaust device, and harmful components from the exhaust gas. An abatement facility 231c for removal is provided. By adjusting the opening degree of the opening / closing valve of the APC valve 231a based on the pressure information from the pressure sensor 245 while operating the vacuum pump 231b, the pressure in the processing chamber 201 can be set to a desired pressure. It is configured.

  An exhaust unit is mainly constituted by the exhaust pipe 231, the pressure sensor 245, the APC valve 231a, the vacuum pump 231b, and the abatement equipment 231c.

  As described above, the space 203a sandwiched between the outer tube 203 and the inner tube 204 communicates with the inside of the processing chamber 201 through the gas exhaust port 204a. Therefore, while supplying the source gas and the reaction gas into the processing chamber 201 from the source gas nozzle 233a or the reaction gas nozzle 233b, the exhaust gas discharges the space 203a sandwiched between the outer tube 203 and the inner tube 204 by the exhaust unit. A substantially horizontal gas flow 10 is generated in the processing chamber 201 from the outlet 248a and the reactive gas outlet 248b to the gas exhaust port 204a. Such a state is shown in FIG.

(controller)
The controller 280 as a control unit includes a heater 207, a pressure sensor 245, an APC valve 231a, a vacuum pump 231b, an abatement equipment 231c, a rotation mechanism 267, a boat elevator 115, open / close valves 241a, 241b, 241e, 241f, 241g, 241h, 241i, 241j, flow rate controllers 242b, 242f, 242g, 242h, a TMA tank 260, an ozonizer 270, an ozone detoxifying device 242j, a temperature sensor (not shown), and the like are connected. The controller 280 adjusts the temperature of the heater 207, opens and closes the APC valve 231a and adjusts the pressure, starts and stops the vacuum pump 231b, adjusts the rotation speed of the rotating mechanism 267, moves the boat elevator 115 up and down, and opens and closes the valves 241a and 241b. Controls such as opening / closing operations of 241e, 241f, 241g, 241h, 241i, 241j, and flow rate adjustment of the flow rate controllers 242b, 242f, 242g, 242h are performed.

(4) Substrate Processing Step Next, the substrate processing step according to the present embodiment will be described with reference to the drawings. FIG. 6 is a flowchart of the substrate processing process according to this embodiment. FIG. 7 is a cross-sectional view schematically showing how an aluminum oxide film (AlO film) 500 is formed on the wafer 200. FIG. 8 is a diagram schematically showing a state of gas supply according to the present embodiment. FIG. 9 is a timing chart relating to gas supply according to the substrate processing process of the present embodiment. In this embodiment, TMA gas is used as a source gas, ozone gas is used as a reaction gas, and a predetermined film, that is, an aluminum oxide film 500 as a high dielectric constant film is formed on the wafer 200 by an ALD method. To explain. The ALD method carried out here is carried out as one step of the semiconductor device manufacturing process. In the following description, the operation of each part constituting the substrate processing apparatus 101 is controlled by the controller 280.

  In the substrate processing step according to the present embodiment, as shown in FIG. 6, a substrate carry-in step S10, a pressure reduction / temperature rise step S20, an aluminum oxide film formation step S30, an atmospheric pressure return step S40, and a substrate carry-out step S50 are performed.

[Substrate loading step S10]
First, a plurality of wafers 200 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 accommodated in the processing chamber 201 (boat loading). In this state, the seal cap 219 is airtightly sealed at the lower end of the manifold 209 via an O-ring (not shown). During wafer charging and boat loading, it is preferable to continue to supply the purge gas into the processing chamber 201 by opening the opening / closing valve 241g and the opening / closing valve 241h.

[Decompression / Temperature raising step S20]
Subsequently, the opening / closing valve 241g and the opening / closing valve 241h are closed, and the processing chamber 201 is evacuated by the vacuum pump 231b so as to have a desired processing pressure (degree of vacuum). At this time, the opening degree of the APC valve 231a is feedback-controlled based on the pressure information measured by the pressure sensor 245. Further, the energization amount to the heater 207 is adjusted so that the surface of the wafer 200 has a desired processing temperature. At this time, feedback control of the power supply to the heater 207 is performed based on temperature information detected by a temperature sensor (not shown). Then, the rotation mechanism 267 starts rotation of the boat 217 and the wafer 200. The temperature adjustment, the pressure adjustment, and the rotation of the wafer 200 are continued until the aluminum oxide film forming step S30 described later is completed.

In addition, as conditions in the processing chamber 201 when the pressure and temperature are stable, for example,
Processing pressure: 1 to 100 Pa, preferably 40 Pa,
Treatment temperature: 450-650 ° C, preferably 550 ° C
Is exemplified.

[Aluminum oxide film forming step S30]
Subsequently, an aluminum oxide film 500 as a high dielectric constant film having a desired thickness is formed on the wafer 200 (see FIG. 7).

(Raw gas supply step S31)
First, the opening / closing valve 241f is opened to supply Ar gas as a carrier gas into the TMA tank 260, and the liquid TMA in the TMA tank 260 is bubbled. Thereby, the liquid TMA is vaporized in the TMA tank 260 to generate TMA gas as a raw material gas. Until the TMA gas is stably generated, the open / close valve 241i is opened with the open / close valve 241a closed, and the mixed gas of TMA gas and Ar gas is discharged from the source gas vent pipe 240i. It should be noted that the generation of TMA gas is performed in parallel with the above-described pressure reduction / temperature increase step S20 (preliminary vaporization), and the amount of TMA gas generated should be stabilized when the pressure reduction / temperature increase step S20 is completed. preferable.

When the TMA gas is stably generated, the on-off valve 241i is closed, the on-off valve 241a is opened, and the mixed gas of TMA gas and Ar gas is introduced into the processing chamber 201 via the source gas nozzle 233a. Start supplying. At that time, the opening / closing valve 241g may be opened, N ₂ gas (dilution gas) may be supplied from the first inert gas supply pipe 240g, and the TMA gas may be diluted in the processing chamber 201. Further, the mixed gas may be pushed out by the N ₂ gas supplied from the first inert gas supply pipe 240g to promote the supply of the mixed gas into the processing chamber 201 (N ₂ push).

  As shown in FIG. 8, the mixed gas supplied from the source gas nozzle 233a into the processing chamber 201 is supplied from the lower end wafer 200 of the boat 217 to the upper end wafer 200, respectively. Then, as shown in FIG. 5, the mixed gas supplied into the processing chamber 201 becomes a substantially horizontal gas flow 10 that passes through each wafer 200 toward the gas exhaust port 204a. The exhaust pipe 231 is exhausted through the port 204a. At that time, the TMA gas supplied to each laminated wafer 200 causes chemical adsorption (surface reaction) with the surface of each wafer 200 or the surface of an adsorption layer of TMA molecules already adsorbed on the wafer 200. Then, an adsorption layer or an Al layer of TMA molecules is formed on the wafer 200. Further, the TMA gas supplied to each wafer 200 is thermally decomposed partly to cause not only an ALD reaction but also a CVD reaction, and includes a bond between aluminum atoms (Al—Al bond) on the wafer 200. An Al layer is formed. Here, the adsorption layer of TMA molecules includes a continuous adsorption layer of TMA molecules, a discontinuous adsorption layer, and a continuous layer formed by overlapping discontinuous layers. In addition, the Al layer includes a discontinuous layer and a continuous layer formed by overlapping discontinuous layers in addition to a continuous layer composed of Al. In addition, Al is an element which becomes a solid by itself. Hereinafter, the TMA molecule adsorption layer and the Al layer formed on the wafer 200 are also referred to as an Al-containing layer 500a. FIG. 7B shows a state in which the Al-containing layer 500 a is formed on each wafer 200.

  After the supply of the mixed gas is continued for a predetermined time, the open / close valve 241a is closed, the open / close valve 241i is opened, and the supply of the TMA gas into the processing chamber 201 is stopped while the generation of the TMA gas is continued. Note that the open / close valve 241f is kept open, and the supply of Ar gas into the TMA tank 260 is continued.

(Exhaust process S32)
Subsequently, with the open / close valves 241a and 241b closed, the open / close valve 241g and the open / close valve 241h are opened to supply the N ₂ gas (purge gas) to purge the inside of the process chamber 201 while exhausting the inside of the process chamber 201. Thus, TMA gas (residual gas) remaining in the processing chamber 201 is removed. When the atmosphere in the processing chamber 201 is replaced (purged) with the N ₂ gas after a predetermined time has elapsed, the opening / closing valve 241g and the opening / closing valve 241h are closed to stop the supply of N ₂ gas into the processing chamber 201. By performing the exhaust process S32, as shown in FIG. 9, the TMA gas supplied in the source gas supply process S31 and the ozone gas supplied in the reaction gas supply process S33 described later can be prevented from being mixed with each other. The purge may be repeated a predetermined number of times (cycle purge). In this case, the TMA gas remaining in the processing chamber 201 can be removed more reliably.

(Reactive gas supply step S33)
Subsequently, ozone gas as a reaction gas is supplied into the processing chamber 201 to oxidize the Al-containing layer 500 a on the wafer 200. First, the open / close valve 241e is opened and oxygen gas is supplied to the ozonizer 270 to generate ozone gas (oxidant) as a reaction gas. Until the ozone gas is stably generated, the open / close valve 241j is opened with the open / close valve 241b closed, and the ozone gas is discharged from the reaction gas vent pipe 240j. The generation of ozone gas is preferably performed in parallel with the above-described pressure reduction / temperature increase step S20, and the amount of ozone gas generated is preferably stabilized when the pressure reduction / temperature increase step S20 is completed.

When the ozone gas is stably generated, the opening / closing valve 241j is closed, the opening / closing valve 241b is opened, and supply of ozone gas into the processing chamber 201 via the reaction gas nozzle 233b is started. At this time, the open / close valve 241g may be opened, N ₂ gas (dilution gas) may be supplied from the second inert gas supply pipe 240h, and ozone gas may be diluted in the reaction gas nozzle 233b. Further, the ozone gas may be pushed out by the N ₂ gas supplied from the second inert gas supply pipe 240h to promote the supply of the ozone gas into the processing chamber 201 (N ₂ push).

  The ozone gas supplied from the reaction gas nozzle 233b into the processing chamber 201 becomes a horizontal gas flow 10 from the reaction gas outlet 248b to the gas exhaust port 204a, as in the case of the source gas shown in FIG. Exhausted. At that time, the ozone gas supplied to each laminated wafer 200 comes into contact with the Al-containing layer 500a on each wafer 200 and oxidizes them. FIG. 7C shows a state in which the aluminum oxide layer 500 b is formed on each wafer 200.

  After the ozone gas supply is continued for a predetermined time, the open / close valve 241b is closed and the open / close valve 241j is opened to stop the supply of the ozone gas into the processing chamber 201 while the generation of the ozone gas is continued.

(Exhaust process S34)
Subsequently, ozone gas (residual gas) remaining in the processing chamber 201 is removed by the same procedure and processing conditions as those in the exhaust process S32. By performing the exhaust process S34, as shown in FIG. 9, the ozone gas supplied in the reaction gas supply process S33 and the TMA gas supplied in the source gas supply process S31 of the next cycle can be prevented from being mixed with each other. .

  Thereafter, the source gas supply step S31 to the exhaust step S34 are set as one cycle, and this cycle is performed a predetermined number of times to form the aluminum oxide layer 500b, thereby forming the aluminum oxide film 500 having a desired thickness on the wafer 200. (FIG. 7D). The film thickness of the aluminum oxide film 500 can be controlled by adjusting the number of cycles. In addition, as processing conditions of each process, it can be set as the conditions as shown below, for example.

<Processing conditions of source gas supply process S31>
Processing pressure: 50 to 150 Pa, preferably 100 Pa,
Carrier gas (Ar gas) flow rate: 0.1-2 slm, preferably 0.5 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 5 to 20 seconds, preferably 10 seconds Flow rate of dilution gas (N ₂ gas): 10 to 20 slm, preferably 17 slm

<Processing conditions of reaction gas supply process S33>
Processing pressure: 50 to 200 Pa, preferably 70 Pa,
Reaction gas (ozone gas) flow rate: 3 to 20 slm, preferably 6 slm,
Flow rate of dilution gas (N ₂ gas): 0 to ₂ slm, preferably 0.5 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 10 to 60 seconds, preferably 20 seconds

<Processing conditions of exhaust steps S32 and S34>
Processing pressure: 50 to 200 Pa, preferably 100 Pa,
Flow rate of purge gas (N ₂ gas) (first inert gas supply pipe): 1 to 10 slm, preferably 5 slm,
Flow rate of purge gas (N ₂ gas) (second inert gas supply pipe): 1 to 10 slm, preferably 5 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 5 to 60 seconds, preferably 10 seconds

[Atmospheric pressure return step S40]
After the aluminum oxide film 500 having a desired thickness is formed on the wafer 200, the opening degree of the APC valve 231a is reduced, the opening / closing valve 241g and the opening / closing valve 241h are opened, and the inside of the process tube 205 (inside the processing chamber 201). N ₂ gas (purge gas) is supplied into the processing chamber 201 until the pressure in the outer tube 203 becomes atmospheric pressure.

[Substrate unloading step S50]
Then, the boat 217 is unloaded from the processing chamber 201 (boat unloading) and the film-formed wafers 200 are detached from the boat 217 (wafer discharge) in the reverse order of the substrate loading step S10. Note that, at the time of boat unloading and wafer discharging, it is preferable that the opening / closing valve 241g and the opening / closing valve 241h are opened and the purge gas is continuously supplied into the processing chamber 201.

  Thereafter, for example, a process of forming a conductive film such as a wiring or an electrode, a process of forming another insulating film, a heat treatment process, and the like are sequentially performed on the wafer 200 on which the aluminum oxide film 500 is formed. A semiconductor device having 500;

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

  (A) The vertical portion of the source gas nozzle 233 a according to the present embodiment is configured to be disposed at a predetermined position below the planned storage area of the wafer 200 in the processing chamber 201. According to this configuration, even if the processing temperature is raised, the temperature rise inside the source gas nozzle 233a can be suppressed, so that the thermal decomposition of the TMA gas inside the source gas nozzle 233a can be suppressed. Thereby, CVD reaction between aluminum atoms in the source gas nozzle 233a is suppressed. Further, it is possible to suppress deposition of reaction products and decomposition products of TMA gas on the inner wall of the source gas nozzle 233a, and to prevent clogging of the source gas nozzle 233a.

  (B) Also, according to the present embodiment, reaction products and decomposition products are difficult to deposit on the raw material gas nozzle 233a, and the flow path of the TMA gas is difficult to be narrowed. TMA gas can be supplied.

  (C) Further, according to the present embodiment, since it is possible to perform the substrate processing at a higher processing temperature, carbon atoms, hydrogen atoms, etc. constituting the TMA gas remain in the aluminum oxide film 500. The amount of impurities in the aluminum oxide film 500 can be reduced. Thereby, the function as a high dielectric constant film can be improved, for example, a decrease in dielectric constant due to impurities can be suppressed and leakage current can be reduced.

  (D) Moreover, when it is difficult to deposit decomposition products on the source gas nozzle 233a as in this embodiment, the cleaning cycle of the source gas nozzle 233a can be lengthened. As a result, the period during which the substrate processing apparatus 101 is stopped by maintenance is shortened, so that the substrate processing apparatus 101 can be operated efficiently and productivity can be improved. Further, when the decomposition product accumulates, the material gas nozzle 233a may be damaged due to a difference in thermal stress between the material gas nozzle 233a and the decomposition product. However, according to the present embodiment, such a material gas nozzle 233a is hardly damaged. Become.

  Here, in order to compare with the substrate processing apparatus 101 of this embodiment, the structure of the raw material gas nozzle of the conventional substrate processing apparatus is demonstrated easily. FIG. 17 is a sectional view schematically showing a conventional substrate processing apparatus and a source gas nozzle 933a in which a decomposition product 950 is deposited. 19 and 20 are explanatory views showing an example of the source gas nozzle 933a in which the decomposition product 950 is deposited. As shown in FIG. 17, in the conventional substrate processing apparatus, the raw material gas nozzle 933 a having a plurality of raw material gas outlets 948 a extends to the vicinity of the upper end of the boat 917. Further, the vertical portion of the source gas nozzle 933a is installed in a space surrounded by a heater (not shown) in the processing chamber 901. Therefore, at the time of substrate processing, the temperature inside the raw material gas nozzle 933a has risen above the thermal decomposition temperature of the TMA gas, and the TMA gas may be thermally decomposed before being supplied into the processing chamber 901. And as shown in FIG. 17, the decomposition product 950 produced | generated from TMA gas may accumulate on the inner wall of the source gas nozzle 933a. Specific examples of the source gas nozzle 933a in which the decomposition product 950 is accumulated are shown in FIGS. 19A, 19B, 20A, and 20B, respectively. Moreover, if the substrate processing is lowered so that the source gas is not thermally decomposed in the source gas nozzle 933a, carbon atoms and hydrogen atoms contained in the source gas molecules remain in the formed thin film, and impurities in the thin film In some cases, the amount increased. According to this embodiment, since the source gas nozzle 233a is configured as a short nozzle and the processing temperature is relatively high, these problems can be solved.

<Second Embodiment of the Present Invention>
In the first embodiment, the source gas nozzle 233a is not configured as a porous long nozzle like the reaction gas nozzle 233b, but as a short nozzle whose vertical portion is disposed below the region where the wafer 200 is to be accommodated. It was. However, if the source gas nozzle 233a is configured as a short nozzle, the thermal decomposition of the source gas inside the source gas nozzle 233a can be suppressed, but the supply amount of TMA gas is locally within the processing chamber 201 (between the wafers 200). There was a case where it fluctuated. For example, the supply amount of the TMA gas for each cycle to the wafer 200 increases in the upper wafer 200 in the processing chamber 201 and decreases in the lower wafer 200 in some cases. As a result, the film thickness of the aluminum oxide film 500 formed on the wafer 200 may vary between the wafers 200.

  The variation in film thickness between the wafers 200 tended to increase especially when the processing temperature was raised in an attempt to reduce the amount of impurities in the aluminum oxide film 500. This is considered to be caused by the fact that when the processing temperature is raised, not only the ALD reaction but also the CVD reaction occurs in the processing chamber 201. As described above, when the processing temperature is increased, a part of the TMA gas supplied to each wafer 200 is thermally decomposed to cause not only an ALD reaction but also a CVD reaction. An Al layer including a bond between them is formed. The thickness of the Al layer formed by this CVD reaction greatly depends on the supply amount of TMA gas, unlike the case of the ALD reaction in which self-limitation is caused by saturation of gas molecule adsorption. For this reason, if the supply amount of the TMA gas locally varies in the processing chamber 201, the thickness of the Al-containing layer 500a, that is, the thickness of the aluminum oxide film 500 also varies.

  Therefore, in this embodiment, even if the source gas nozzle 233a is configured as a short nozzle by providing a plurality of processes for supplying TMA gas at different flow rates in the same cycle, the inside of the processing chamber 201 (between the wafers 200). The local variation in the supply amount of TMA gas is reduced. Specifically, TMA supply processing into the processing chamber 201 at the first flow rate and TMA gas supply processing into the processing chamber 201 at a second flow rate different from the first flow rate. By sequentially performing the process, local variations in the supply amount of the TMA gas between the wafers 200 are reduced. For example, a process of locally supplying TMA gas mainly to the lower wafer 200 in the processing chamber 201 at a first flow rate, and an upper portion in the processing chamber 201 mainly at a second flow rate larger than the first flow rate. If the step of locally supplying the TMA gas to the wafer 200 on the side is performed sequentially within the cycle, the TMA gas supply amount when viewed in the entire cycle can be made more uniform between the wafers 200. Can do. That is, in this embodiment, the TMA gas is not uniformly supplied to all the wafers 200 in one source gas supply process, but a part of the wafers 200 is intentionally used in one source gas supply process. The TMA gas is supplied locally only, and then the flow of the flow rate is changed to switch the place where the TMA gas is mainly supplied. By doing so, local variations in the supply amount of the TMA gas are reduced.

  Hereinafter, the present embodiment will be described. In addition, below, it demonstrates, omitting the content which overlaps with 1st Embodiment suitably.

(1) Configuration of Processing Furnace The controller 280 according to the present embodiment is configured to perform a predetermined number of cycles including a process of supplying a source gas into the processing chamber 201 so as not to mix with each other at different flow rates. For example, the controller 280 mainly supplies the TMA gas to the lower wafer 200 in the processing chamber 201 at the first flow rate, and mainly in the processing chamber 201 at the second flow rate higher than the first flow rate. And a process of supplying TMA gas to the wafer 200 on the upper side of the wafer.

In order to switch the flow rate of the TMA gas between the first flow rate and the second flow rate, for example, the first inert gas supply pipe while keeping the flow rates of the TMA gas as the source gas and the Ar gas as the carrier gas constant, respectively. it may be changed the flow rate of _{N 2} gas supplied from 240 g. Specifically, the flow rate can be increased without changing the flow rate of the TMA gas by increasing the flow rate of the N ₂ gas supplied from the first inert gas supply pipe 240g. Further, by reducing the flow rate of the N ₂ gas supplied from the first inert gas supply pipe 240g, the flow velocity can be reduced without changing the flow rate of the TMA gas. As described above, in the present embodiment, the inert gas supplied from the first inert gas supply pipe 240g has the flow rate of the TMA gas supplied into the processing chamber 201 in addition to the functions as the dilution gas and the purge gas described above. It also has a function as a flow rate adjusting gas that makes the difference between the two.

(2) Substrate Processing Step FIG. 10 is a flowchart of the substrate processing step according to this embodiment. FIG. 11 is a diagram schematically showing the state of the raw material gas supply according to the present embodiment. (A) When the flow rate of the raw material gas is the first flow rate, (b) the flow rate of the raw material gas is the first flow rate. The cases where the second flow rate is larger than the flow rate are shown. FIG. 12 is a timing chart according to the gas supply of the present embodiment. With reference to these drawings, the substrate processing process according to the present embodiment will be described. FIG. 13 is a diagram showing a TMA gas supply sequence and processing conditions according to this embodiment in comparison with the conventional one.

  In the substrate processing step of this embodiment, as shown in FIG. 10, a substrate carry-in step S10, a pressure reduction / temperature rise step S20, an aluminum oxide film formation step S130, an atmospheric pressure return step S40, and a substrate carry-out step S50 are performed. Since steps other than the aluminum oxide film forming step S130 are performed in the same processing procedure and processing conditions as those in the first embodiment, detailed description thereof is omitted here.

[Aluminum oxide film forming step S130]
In the present embodiment, the first source gas supply step S131 to the exhaust step S136 shown below is set as one cycle, and the aluminum oxide film 500 having a desired thickness is formed on the wafer 200 by performing this cycle a predetermined number of times. To do. Here, it is assumed that TMA gas is stably generated from the TMA tank 260 and ozone gas is stably generated from the ozonizer 270 when the decompression / temperature raising step S20 is completed.

(First source gas supply step S131)
In the first source gas supply step S131, the TMA gas is supplied into the processing chamber 201 by a processing procedure substantially similar to that of the source gas supply step S31 according to the first embodiment. At this time, for example, as shown in FIG. 11A, the flow rate of the TMA gas is adjusted to a relatively small first flow rate so that the TMA gas is mainly supplied to the lower wafer 200 in the processing chamber 201. To do. Specifically, the flow rate of the TMA gas is adjusted to the first flow rate by decreasing the flow rate of the N ₂ gas (flow rate adjusting gas) supplied from the first inert gas supply pipe 240g.

  The TMA gas supplied from the source gas nozzle 233a becomes a gas flow in a substantially horizontal direction mainly on the lower wafer 200 in the processing chamber 201 while moving from the source gas outlet 248a to the gas exhaust port 204a. . The TMA gas that has passed through the wafer 200 is then exhausted from the exhaust pipe 231. The TMA gas supplied to each wafer 200 causes chemical adsorption (surface reaction) with the surface of each wafer 200 or the surface of an adsorption layer of TMA molecules already adsorbed on the wafer 200. As a result, an Al-containing layer 500 a shown in FIG. 7B is formed mainly on the lower wafer 200 in the processing chamber 201.

(Exhaust process S132)
Subsequently, in the evacuation step S132, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S32 according to the first embodiment. By performing the exhaust step S132, as shown in FIG. 12A, the TMA gas supplied in the first source gas supply step S131 and the TMA gas supplied in the second source gas supply step S133 described later are Try not to mix with each other.

(Second source gas supply step S133)
Subsequently, TMA gas is supplied into the processing chamber 201 by a processing procedure substantially similar to that of the source gas supply step S31 according to the first embodiment. At this time, for example, as shown in FIG. 11B, the second flow rate of the TMA gas is larger than the first flow rate so that the TMA gas is mainly supplied to the lower wafer 200 in the processing chamber 201. Adjust to the flow rate of. Specifically, the flow rate of TMA gas is increased without changing the flow rate of TMA gas from step S131 by increasing the flow rate (flow rate adjusting gas) of N ₂ gas supplied from the first inert gas supply pipe 240g. Switch to the second flow rate.

  The TMA gas supplied from the source gas nozzle 233a becomes a gas flow in a substantially horizontal direction mainly on the upper wafer 200 in the processing chamber 201 while moving from the source gas outlet 248a to the gas exhaust port 204a. The TMA gas that has passed through the wafer 200 is then exhausted from the exhaust pipe 231. The TMA gas supplied to each wafer 200 causes chemical adsorption (surface reaction) with the surface of each wafer 200 or the surface of an adsorption layer of TMA molecules already adsorbed on the wafer 200. As a result, an Al-containing layer 500 a shown in FIG. 7B is formed mainly on the upper wafer 200 in the processing chamber 201. At this time, since the flow rate of the TMA gas is not changed in the steps S131 and S133, the supply amount of the TMA gas to the wafer 200 is equal in the steps S131 and S133. Therefore, the thickness of the Al-containing layer 500a formed on the wafers 200 can be easily made uniform between the wafers 200 by aligning the processing times of the process S131 and the process S133.

(Exhaust process S134)
Subsequently, in the evacuation step S134, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S32 according to the first embodiment. By performing the exhaust process S134, as shown in FIG. 11A, the TMA gas supplied in the second source gas supply process S133 and the ozone gas supplied in the reaction gas supply process S135 described later do not mix with each other. I am doing so.

(Reactive gas supply step S135)
Subsequently, in the reactive gas supply step S135, ozone gas is supplied into the processing chamber 201 by substantially the same processing procedure and processing conditions as the reactive gas supply step S33 according to the first embodiment. The ozone gas supplied from the reaction gas nozzle 233b into the process chamber 201 becomes a horizontal gas flow 10 from the reaction gas outlet 248b to the gas exhaust port 204a, as in the case of the source gas shown in FIG. Is done. At that time, ozone gas is supplied to each laminated wafer 200, and the ozone gas oxidizes the Al-containing layer 500a on each wafer 200 to form an aluminum oxide layer 500b (FIG. 7C). Since the reactive gas nozzle 233b is configured as a porous long nozzle as described above, the supply amount of ozone gas to the wafers 200 is uniform among the wafers 200.

(Exhaust process S136)
Subsequently, in the exhaust process S136, the inside of the processing chamber 201 is purged by the same processing procedure and processing conditions as in the exhaust process S34 according to the first embodiment. By performing the exhaust process S136, the ozone gas supplied in the reactive gas supply process S135 and the TMA gas supplied in the first source gas supply process S131 of the next cycle as shown in FIG. Try not to mix with each other.

  Thereafter, the first source gas supply step S131 to the exhaust step S136 are set as one cycle, and this cycle is performed a predetermined number of times to form an aluminum oxide film 500 (FIG. 7D) having a desired thickness on the wafer 200. To do. In addition, as processing conditions of each process, it can be set as the conditions as shown below, for example.

<Processing conditions of 1st source gas supply process S131>
Processing pressure: 20 to 100 Pa, preferably 50 Pa,
Carrier gas (Ar gas) flow rate: 0.1-2 slm, preferably 0.5 slm,
Flow rate of flow rate adjusting gas (N ₂ gas): 1 to 5 slm, preferably 3 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 2 to 10 seconds, preferably 5 seconds

<Processing conditions of second source gas supply step S133>
Processing pressure: 50 to 200 Pa, preferably 120 Pa,
Carrier gas (Ar gas) flow rate: 0.1-2 slm, preferably 0.5 slm,
Flow rate of flow rate adjusting gas (N ₂ gas): 10-30 slm, preferably 20 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 2 to 10 seconds, preferably 5 seconds

<Processing conditions of reaction gas supply process S135>
Processing pressure: 50 to 200 Pa, preferably 70 Pa,
Reaction gas (ozone gas) flow rate: 3 to 20 slm, preferably 6 slm,
Flow rate of dilution gas (N ₂ gas): 0 to ₂ slm, preferably 0.5 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 10 to 60 seconds, preferably 20 seconds

<Processing conditions of exhaust steps S132, S134, S136>
Processing pressure: 50 to 200 Pa, preferably 100 Pa,
The flow rate of the flow rate adjusting gas (N ₂ gas) (first inert gas supply pipe): 1 to 10 slm, preferably 5 slm,
The flow rate of the flow rate adjusting gas (N ₂ gas) (second inert gas supply pipe): 1 to 10 slm, preferably 5 slm,
Process temperature: 450-650 degreeC, Preferably it is 550 degreeC,
Implementation time: 5 to 60 seconds, preferably 10 seconds

  In the above-described embodiment, after the TMA gas is supplied at the first flow rate, the TMA gas is supplied at a second flow rate that is larger than the first flow rate. It is not limited. For example, as shown in FIG. 12B, after the TMA gas is mainly supplied to the upper wafer 200 in the processing chamber 201 at the second flow rate, the main flow rate at the first flow rate smaller than the second flow rate is obtained. Alternatively, TMA gas may be supplied to the lower wafer 200 in the processing chamber 201.

  In the above-described embodiment, the TMA gas is sequentially supplied to the two regions in the processing chamber 201 while switching the flow rate of the TMA gas at two stages of the first flow rate and the second flow rate. Is not limited to such a case. For example, the TMA gas may be sequentially supplied to three or more regions in the processing chamber 201 while switching the flow rate of the TMA gas at three or more stages. By increasing the flow rate step, the TMA gas supply amount as seen in one cycle can be made more uniform between the wafers 200.

(3) Effects according to this embodiment According to this embodiment, in addition to the effects according to the first embodiment, the following one or more effects are achieved.

  (A) According to the present embodiment, the first source gas supply step S131 for locally supplying the TMA gas to the lower wafer 200 in the processing chamber 201 mainly at the first flow rate, and the first flow rate. A second source gas supply step S133 for locally supplying TMA gas to the upper wafer 200 in the processing chamber 201 at a larger second flow rate is sequentially performed for each cycle. That is, instead of trying to supply the TMA gas evenly to all the wafers 200 in one source gas supply process, the TMA gas is intentionally applied only to some of the wafers 200 in one source gas supply process. A plurality of raw material gas supply steps are sequentially performed for each cycle while switching the place where the TMA gas is mainly supplied by changing the flow velocity while locally supplying it. . Thereby, even if the source gas nozzle 233a is configured as a short nozzle, the supply amount of the TMA gas can be made uniform between the wafers 200 when viewed in one cycle. Then, the film thickness uniformity of the aluminum oxide film 500 between the wafers 200 can be improved.

(B) According to the present embodiment, the N ₂ gas as the flow rate adjusting gas is maintained while the flow rates of the TMA gas and the Ar gas are constant in the first source gas supply step S131 and the second source gas supply step S133, respectively. The flow rate of TMA gas is changed by changing only the flow rate of. This simplifies the control related to switching the flow rate of the TMA gas.

(C) Further, according to this embodiment, the flow rate of the TMA gas is changed only by changing the flow rate of the N ₂ gas as the TMA gas flow rate adjusting gas while keeping the flow rates of the TMA gas and the Ar gas constant. I am letting. That is, the supply amount of TMA gas to each wafer 200 is equal in the first source gas supply step S131 and the second source gas supply step S133. Therefore, the thickness of the Al-containing layer 500a formed on the wafer 200, that is, the aluminum oxide, is adjusted by aligning the processing time and the number of execution times of the first source gas supply step S131 and the second source gas supply step S133. The thickness of the film 500 can be easily made uniform between the wafers 200.

<Third Embodiment of the Present Invention>
Next, a third embodiment of the present invention will be described. In the third embodiment, after the supply process of TMA gas into the process chamber 201 at the first flow rate is performed, before the supply process of TMA gas into the process chamber 201 at the second flow rate is performed. Further, the point that the supply process of ozone gas into the processing chamber 201 is performed is different from the second embodiment. That is, in this embodiment, every time TMA gas is supplied into the processing chamber 201 at different flow rates, ozone gas is supplied into the processing chamber 201 to oxidize the Al-containing layer 500a on the wafer 200. This embodiment is particularly effective when the reaction gas has the property of being easily pyrolyzed. That is, it is particularly effective when the reaction gas nozzle 233b is configured as a short nozzle in the same manner as the source gas nozzle 233a. In addition, below, it demonstrates, omitting suitably the content which overlaps with 1st, 2nd embodiment.

(1) Configuration of Processing Furnace In the present embodiment, the controller 280 as the control unit mainly supplies TMA gas to the lower wafer 200 in the processing chamber 201 at the first flow rate, and the processing chamber 201. The supply process of ozone gas into the inside, the supply process of TMA gas to the upper wafer 200 in the process chamber 201 mainly at the second flow rate larger than the first flow rate, and the ozone gas into the process chamber 201 The supply process is defined as one cycle, and this cycle is performed a predetermined number of times. Note that switching of the flow rate of the TMA gas can be performed by a method almost similar to that of the second embodiment.

(2) Substrate Processing Step Next, the substrate processing step according to the present embodiment will be described. FIG. 14 is a flowchart of the substrate processing process according to this embodiment. FIG. 15 is a timing chart according to the gas supply of the present embodiment. With reference to these drawings, the substrate processing process according to the present embodiment will be described.

  In the substrate processing step of this embodiment, as shown in FIG. 14, a substrate carry-in step S10, a pressure reduction / temperature rise step S20, an aluminum oxide film formation step S230, an atmospheric pressure return step S40, and a substrate carry-out step S50 are performed. Since steps other than the aluminum oxide film formation step S230 are performed in the same processing procedure and processing conditions as those in the first and second embodiments, detailed description thereof is omitted here.

[Aluminum oxide film forming step S230]
In the present embodiment, a first source gas supply step S231 to an exhaust step S238 described below is set as one cycle, and this cycle is performed a predetermined number of times to form an aluminum oxide film 500 having a desired thickness on the wafer 200. To do.

(First source gas supply step S231)
In the first source gas supply step S231, the lower wafer in the processing chamber 201 is mainly used at the first flow rate according to substantially the same procedure and processing conditions as the first source gas supply step S131 of the second embodiment. 200 is supplied with TMA gas (see FIG. 11A), and an Al-containing layer 500a shown in FIG.

(Exhaust process S232)
Subsequently, in the evacuation step S232, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S32 according to the first embodiment. By performing the exhaust process S232, as shown in FIG. 15A, the TMA gas supplied in the first source gas supply process S231 and the ozone gas supplied in the reaction gas supply process S233 described later do not mix with each other. I am doing so.

(Reactive gas supply step S233)
Subsequently, in the reactive gas supply step S233, ozone gas is supplied into the processing chamber 201 based on substantially the same procedure and processing conditions as the reactive gas supply step S33 according to the first embodiment, and the Al-containing layer 500a on the wafer 200 is supplied. The aluminum oxide layer 500b shown in FIG. 7C is formed on the wafer 200. When the reactive gas nozzle 233b is configured as a short nozzle like the source gas nozzle 233a, the flow rate of N ₂ gas (flow rate adjusting gas) and the flow rate of ozone gas from the second inert gas supply pipe 240h are adjusted. The ozone gas flow rate may be adjusted by such as to supply ozone gas mainly to the lower wafer 200 in the processing chamber 201 (wafer 200 to which TMA gas has been supplied in the first source gas supply step S231). .

(Exhaust process S234)
Subsequently, in the evacuation step S234, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S34 according to the first embodiment. By performing the exhaust process S234, as shown in FIG. 15A, the ozone gas supplied in the reaction gas supply process S233 and the TMA gas supplied in the first source gas supply process S231 described later do not mix with each other. I am doing so.

(Second source gas supply step S235)
Subsequently, in the second raw material gas supply step S235, the upper part of the processing chamber 201 is mainly formed at the second flow rate according to substantially the same procedure and processing conditions as the second raw material gas supply step S133 of the second embodiment. A TMA gas is supplied to the wafer 200 on the side (see FIG. 11B), and an Al-containing layer 500a shown in FIG. At this time, since the flow rate of the TMA gas is not changed between the step S231 and the step S235, the supply amount of the TMA gas to the wafer 200 is equal in the step S231 and the step S235. Therefore, the thickness of the Al-containing layer 500a formed on the wafers 200 can be made uniform between the wafers 200 by aligning the processing times of the process S231 and the process S235.

(Exhaust process S236)
Subsequently, in the evacuation step S236, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S34 according to the first embodiment. By performing the exhaust process S236, as shown in FIG. 15A, the TMA gas supplied in the second source gas supply process S235 and the ozone gas supplied in the reaction gas supply process S237 described later do not mix with each other. I am doing so.

(Reactive gas supply step S237)
Subsequently, in the reactive gas supply step S237, ozone gas is supplied into the processing chamber 201 by substantially the same procedure and processing conditions as in the reactive gas supply step S33 according to the first embodiment, and the Al-containing layer 500a on the wafer 200 is formed. The aluminum oxide layer 500b shown in FIG. 7C is formed on the wafer 200 by oxidation. When the reaction gas nozzle 233b is configured as a short nozzle like the source gas nozzle 233a, the flow rate of ozone gas is adjusted in the same manner as in the reaction gas supply step S233, and the wafer 200 ( The ozone gas may be supplied to the wafer 200) to which the TMA gas has been supplied in the second source gas supply step S235.

(Exhaust process S238)
Subsequently, in the evacuation step S238, the inside of the processing chamber 201 is purged by the processing procedure and processing conditions substantially the same as those in the evacuation step S34 according to the first embodiment. By performing the exhaust process S238, as shown in FIG. 15A, the ozone gas supplied in the reactive gas supply process S237 and the TMA gas supplied in the first source gas supply process S231 of the next cycle are mutually connected. Try not to mix.

  In the embodiment described above, the TMA gas is mainly supplied to the upper wafer 200 in the processing chamber 201 at the second flow rate, and then the processing chamber is mainly used at the first flow rate smaller than the second flow rate. The TMA gas may be supplied to the lower wafer 200 in the 201. Alternatively, the TMA gas may be sequentially supplied to three or more regions in the processing chamber 201 while switching the flow rate of the TMA gas in three or more stages.

(3) Effects according to this embodiment According to this embodiment, in addition to the effects according to the first and second embodiments, the following effects can be obtained.

  In this embodiment, after supplying TMA gas mainly to the wafer 200 on the lower side of the boat 217 in the first source gas supply step S231, ozone gas is supplied into the processing chamber 201 in the reaction gas supply step S233, and then In the second source gas supply step S235, TMA gas is mainly supplied to the wafer 200 on the upper side of the boat 217. Thus, the film thickness is particularly large in the wafer 200 near the boundary between the region where the TMA gas is supplied in the first source gas supply step S231 and the region where the TMA gas is supplied in the second source gas supply step S235. Since the Al-containing layer 500a is oxidized before being thickened, uneven oxidation can be suppressed, and variations in film quality in the aluminum oxide layer 500b can be suppressed.

  In addition, this embodiment is particularly effective when the reaction gas has the property of being easily thermally decomposed. That is, in order to avoid thermal decomposition of the reaction gas, even when the reaction gas nozzle 233b is configured as a short nozzle like the source gas nozzle 233a, the flow rates of the reaction gas are different in the reaction gas supply step S233 and the reaction gas supply step S237. Thus, similarly to the raw material gas, the reaction gas supply amount when viewed in one cycle can be made uniform between the wafers 200.

<Fourth Embodiment of the Present Invention>
In the above-described embodiment, the flow rate of N ₂ gas (flow rate adjusting gas) supplied from the first inert gas supply pipe 240g is made different while keeping the flow rate of TMA gas and Ar gas (carrier gas) constant. The flow rate of TMA gas was switched between the first flow rate and the second flow rate. However, the present invention is not limited to such an embodiment. For example, as in the present embodiment, the flow rate of the TMA gas itself is changed while keeping the flow rate of the N ₂ gas (flow rate adjusting gas) supplied from the first inert gas supply pipe 240g constant (or without supply). Thus, the flow rate of the TMA gas may be switched between the first flow rate and the second flow rate. For example, when the TMA gas is supplied to the lower wafer 200 in the processing chamber 201, the flow rate of the TMA gas is decreased to reduce the flow rate of the TMA gas (first flow rate), and the upper side in the processing chamber 201. When the TMA gas is supplied to the wafer 200, the flow rate of the TMA gas is increased to increase the flow rate of the TMA gas (second flow rate).

  Note that when the flow rate of the TMA gas itself is changed, the supply amount of the TMA gas into the processing chamber 201, that is, the supply amount of the TMA gas to the wafer 200 is also changed. Therefore, when the flow rate of the TMA gas itself is changed to change the flow rate of the TMA gas, the supply time and the number of times of supply of the TMA gas per cycle may be adjusted. For example, when the flow rate of the TMA gas is increased by increasing the flow rate of the TMA gas itself, the supply time and the number of times of supply of the TMA gas may be reduced. Similarly, when the flow rate of the TMA gas is reduced by reducing the flow rate of the TMA gas itself, the supply time and the number of times of supply of the TMA gas may be increased.

<Fifth Embodiment of the Present Invention>
The flow rate of TMA gas can also be adjusted by the diameter of the gas injection port. For example, when the diameter of the gas injection port is wide, the flow rate of TMA gas supplied into the processing chamber 201 is slow, and when the diameter of the gas injection port is narrow, the flow rate of TMA gas supplied into the processing chamber 201 is high. Therefore, in the present embodiment, the diameter of the gas injection port is set at a predetermined position in the nozzle accommodating portion 201a below the planned accommodation region of the wafer 200 while aligning the height positions of the gas injection ports in the nozzle accommodating portion 201a. A plurality of different source gas nozzles are provided. The raw material gas nozzle having a large diameter of the gas injection port is configured to supply the TMA gas mainly to the lower wafer 200 in the processing chamber 201 at the first flow rate. On the other hand, the raw material gas nozzle having a small diameter of the gas injection port is configured to supply the TMA gas mainly to the upper wafer 200 in the processing chamber 201 at the second flow rate.

In this embodiment, the flow rate of TMA gas can be adjusted without changing the flow rate of N ₂ gas (flow rate adjusting gas) or TMA gas. Note that the upstream end of the source gas nozzle according to the present embodiment may be connected to the downstream end of the source gas supply pipe 240a branched into a plurality of branches, for example. In that case, an open / close valve may be provided at each branch portion of the source gas supply pipe 240a connected to the source gas nozzle. Further, the opening / closing operation of the opening / closing valve of the source gas nozzle may be controlled by the controller 280. With such a configuration, the flow rate of the TMA gas supplied from the source gas supply pipe 240a can be switched only by the opening / closing operation of the opening / closing valve of the source gas nozzle. This simplifies the control related to the flow rate of the TMA gas.

<Sixth Embodiment of the Present Invention>
The flow rate of TMA gas can also be adjusted by the length of the source gas nozzle (or the surface roughness of the nozzle inner wall). Since the TMA gas flows through the nozzle while causing friction with the inner wall of the source gas nozzle, for example, if the source gas nozzle is long (or if the surface roughness of the nozzle inner wall is large), the friction is large and is supplied into the processing chamber 201. The flow rate of the TMA gas is slow, and if the raw material gas nozzle is short (or if the surface roughness of the nozzle inner wall is small), the friction is small and the flow rate of the TMA gas supplied into the processing chamber 201 is fast. Therefore, in the present embodiment, the lengths of the gas injection ports in the nozzle accommodating portion 201a are aligned to a predetermined position in the nozzle accommodating portion 201a below the region where the wafer 200 is to be accommodated (or the length is different) (or A plurality of source gas nozzles (with different surface roughness on the inner wall of the nozzle) are provided. A long source gas nozzle (or a nozzle with a large inner wall surface roughness) is configured to supply TMA gas mainly to the lower wafer 200 in the processing chamber 201 at a first flow rate. In contrast, a short source gas nozzle (or a nozzle with a small inner wall surface roughness) is configured to supply TMA gas mainly to the upper wafer 200 in the processing chamber 201 at the second flow rate. .

Also in this embodiment, the flow rate of TMA gas can be adjusted without changing the flow rate of N ₂ gas (flow rate adjusting gas) or TMA gas. Note that the upstream ends of the plurality of source gas nozzles according to the present embodiment may be connected to the downstream ends of the plurality of source gas supply pipes 240a branched, for example. In that case, an open / close valve may be provided at each branch portion of the source gas supply pipe 240a connected to the source gas nozzle. Further, the opening / closing operation of the opening / closing valve of the source gas nozzle may be controlled by the controller 280. With such a configuration, the flow rate of the TMA gas supplied from the source gas supply pipe 240a can be switched only by the opening / closing operation of the opening / closing valve of the source gas nozzle. This simplifies the control related to the flow rate of the TMA gas.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to these, A various change is possible in the range which does not deviate from the meaning.

  In the above-described embodiment, the processing chamber 201 includes the nozzle accommodating portion 201a, and the downstream side of the vertical portions of the source gas nozzle 233a and the reaction gas nozzle 233b is accommodated in the nozzle accommodating portion 201a (see FIG. 4). ), The present invention is not limited to such an embodiment. FIG. 16 is a cross-sectional view of a process tube provided in a substrate processing apparatus according to another embodiment of the present invention, and shows a case where the nozzle accommodating portion 201 a is not provided in the processing chamber 201. As described above, the source gas nozzle 233a and the reactive gas nozzle 233b may be arranged in the immediate vicinity of the boat 217 (wafer 200).

  In the above-described embodiment, TMA containing, for example, aluminum atoms is used as the liquid raw material, but the present invention is not limited to such a form. That is, other organic compounds or chlorides containing any of Si atom, Hf atom, Zr atom, Al atom, Ta atom, Ti atom, Ru atom, Ir atom, Ge atom, Sb atom, Te atom as a liquid raw material It may be used. Further, the present invention is not limited to the case where TMA gas obtained by vaporizing TMA is used as the first source gas, and Si atom, Hf atom, Zr atom, Al atom, Ta atom, Ti atom, Ru atom, Ir atom, Ge atom, Other gases obtained by vaporizing or decomposing organic compounds or chlorides containing either Sb atoms or Te atoms may be used.

In the above embodiment, the oxide film is formed using ozone gas as the reaction gas. However, in addition to this, for example, the oxide film is formed using an oxidizing agent such as O ₂ gas or H ₂ O gas. Also good. In addition, a nitride film may be formed using a nitriding agent such as ammonia gas, N ₂ gas, N ₂ O, or NO ₂ as the reactive gas.

  In the above-described embodiment, the case where the aluminum oxide film is formed on the wafer 200 has been described. In addition, the Hf oxide film, the Si oxide film, the AI oxide film, the Ta oxide film, the Ti oxide film, the Ru oxide film, and the Ir oxide film are described. The present invention can also be suitably applied when forming any one of a film, a Si nitride film, an AI nitride film, a Ti nitride film, and a GeSbTe film.

  Examples of the present invention will be described below. In this example, an aluminum oxide film was formed on the wafer by the same method as in the second embodiment. FIG. 18 is a diagram showing the presence / absence of deposition of decomposition products in the nozzle and the film characteristics of the aluminum oxide film while comparing this example with the conventional example. Note that the gas supply conditions relating to the film formation of these aluminum oxides are shown in FIG.

In the first source gas supply process of the present embodiment, as shown in FIG. 13, the flow rate of Ar gas as a carrier gas was 0.5 slm, and the flow rate of N ₂ gas as a flow adjustment gas was 3 slm. In the second source gas supply step, as shown in FIG. 13, the flow rate of Ar gas as a carrier gas was set to 0.5 slm, and the flow rate of N ₂ gas as a flow rate adjusting gas was set to 20 slm.

On the other hand, in the conventional example, as shown in FIG. 13, the flow rate of Ar gas as a carrier gas is 0.5 slm, and the flow rate of N ₂ gas is 15 slm.

  In FIG. 18, the film thickness of the aluminum oxide film, the in-plane uniformity of the film thickness, the film-to-wafer uniformity, the film characteristics of the amount of impurities in the film, and the presence or absence of deposition of decomposition products in the source gas nozzle However, the embodiment and the conventional example are shown in comparison.

  When the film was formed by increasing the processing temperature from 380 ° C. to 550 ° C., in the example, the decomposition product of TMA gas was not deposited in the raw material gas nozzle. On the other hand, in the conventional example, a decomposition product of TMA gas was deposited in the raw material gas nozzle.

  In the example, even when the film was formed at 550 ° C., the film thickness uniformity between the wafers was ± 1.1%. On the other hand, in the conventional example, when film formation is performed by increasing the processing temperature from 380 ° C. to 550 ° C., the film thickness uniformity between the wafer surfaces is ± 1%, but is ± 4.1%. The film thickness variation between wafers increased. Therefore, in the example, although the processing temperature was increased to 550 ° C., the film thickness uniformity between the wafer surfaces was almost the same as the conventional example performed at 380 ° C.

  In the example, 59 foreign substances adhered to the wafer surface. On the other hand, in the conventional example, when the film was formed by raising the processing temperature from 380 ° C. to 550 ° C., the number of foreign matters adhering to the wafer surface was 30, but increased to 500 at the maximum. Therefore, despite an increase in the processing temperature, an increase in the number of foreign matters adhering to the wafer surface was suppressed.

<Preferred embodiment of the present invention>
Hereinafter, desirable aspects of the present invention will be additionally described.

[Appendix 1]
The first aspect of the present invention is:
A processing chamber for accommodating a plurality of substrates stacked in a horizontal position;
A heating unit that is provided outside the processing chamber and heats the processing chamber;
A source gas supply unit for supplying source gas;
A source gas nozzle connected to the source gas supply unit and supplying the source gas supplied from the source gas supply unit into the processing chamber;
An exhaust unit for exhausting the processing chamber in a substantially horizontal direction;
A control unit that controls at least the heating unit, the source gas supply unit, and the exhaust unit;
Have
The source gas nozzle is disposed at a predetermined position in the processing chamber so that the source gas is not decomposed therein even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the source gas. Device.

[Appendix 2]
The second aspect of the present invention is:
A processing chamber for accommodating a plurality of substrates stacked in a horizontal position;
A heating unit that is provided outside the processing chamber and heats the processing chamber;
A source gas supply unit for supplying source gas;
A source gas nozzle connected to the source gas supply unit and supplying the source gas supplied from the source gas supply unit into the processing chamber;
An exhaust unit for exhausting the processing chamber in a substantially horizontal direction;
A control unit that controls at least the heating unit, the source gas supply unit, and the exhaust unit;
Have
The raw material gas nozzle is disposed at a predetermined position in the processing chamber so that the raw material gas is not decomposed therein even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the raw material gas.
The control unit is a substrate processing apparatus configured to perform a predetermined number of cycles including a process of supplying the source gas into the processing chamber so as not to mix with each other at different flow rates.

[Appendix 3]
Preferably,
A reaction gas supply unit for supplying a reaction gas that reacts with the source gas;
A reaction gas nozzle connected to the reaction gas supply unit, disposed in the processing chamber along the stacking direction of the substrates, and supplying the reaction gas supplied from the reaction gas supply unit into the processing chamber;
Have
The control unit is configured to supply the raw material gas into the processing chamber at a first flow rate, and supply the raw material gas into the processing chamber at a second flow rate different from the first flow rate. The reaction gas supply process into the processing chamber is defined as one cycle, and this cycle is performed a predetermined number of times.

[Appendix 4]
The third aspect of the present invention is:
A processing chamber for accommodating a plurality of substrates stacked in a horizontal position;
A heating unit that is provided outside the processing chamber and heats the processing chamber;
A source gas supply unit for supplying source gas;
A source gas nozzle connected to the source gas supply unit and supplying the source gas supplied from the source gas supply unit into the processing chamber;
An exhaust unit for exhausting the processing chamber in a substantially horizontal direction;
A control unit that controls at least the heating unit, the source gas supply unit, and the exhaust unit;
Have
The raw material gas nozzle is disposed at a predetermined position below the processing chamber so that the raw material gas is not decomposed inside even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the raw material gas. , A source gas outlet is established to supply the source gas toward the upper part of the processing chamber,
The control unit is configured to supply the source gas to the substrate accommodated on the lower side of the processing chamber at a first flow rate, and to process the chamber at a second flow rate higher than the first flow rate. The substrate processing apparatus is configured to perform a predetermined number of cycles including the process of supplying the source gas to the other substrates accommodated on the upper side of the substrate.

[Appendix 5]
The fourth aspect of the present invention is:
An inner tube configured in the internal space of a processing chamber that accommodates a plurality of substrates stacked in a horizontal posture; and
An outer tube surrounding the inner tube;
A heating unit that is provided outside the outer tube and heats the processing chamber;
A source gas supply unit for supplying source gas;
A source gas nozzle connected to the source gas supply unit and supplying the source gas supplied from the source gas supply unit into the processing chamber via a source gas supply port;
A gas exhaust port established in the side wall of the inner tube;
An exhaust unit that exhausts the processing chamber while exhausting a space between the outer tube and the inner tube to generate a substantially horizontal gas flow from the source gas outlet to the gas outlet. When,
A control unit that controls at least the heating unit, the source gas supply unit, and the exhaust unit;
Have
The raw material gas nozzle is disposed at a predetermined position below the processing chamber so that the raw material gas is not decomposed inside even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the raw material gas. The raw material gas outlet is opened to supply the raw material gas toward the upper part of the processing chamber,
The control unit is configured to supply the source gas to the substrate accommodated on the lower side of the processing chamber at a first flow rate, and to process the chamber at a second flow rate higher than the first flow rate. The substrate processing apparatus is configured to perform a predetermined number of cycles including the process of supplying the source gas to the other substrates accommodated on the upper side of the substrate.

[Appendix 6]
Preferably,
A reaction gas supply unit for supplying a reaction gas that reacts with the source gas;
A reaction gas nozzle connected to the reaction gas supply unit, disposed in the processing chamber along the stacking direction of the substrates, and supplying the reaction gas supplied from the reaction gas supply unit into the processing chamber;
Have
The control unit is configured to perform one cycle of the source gas supply process at the first flow rate, the source gas supply process at the second flow rate, and the reaction gas supply process as one cycle. It is configured to be executed a predetermined number of times.

[Appendix 7]
Also preferably,
An inert gas supply pipe for supplying an inert gas to the source gas nozzle is connected;
The control unit is configured to vary the flow rate of the source gas between the first flow rate and the second flow rate by changing the flow rate of the inert gas.

[Appendix 8]
Also preferably,
The controller is
By changing the flow rate of the source gas, the flow rate of the source gas is made different between the first flow rate and the second flow rate,
The source gas supply process at the first flow rate is configured to be performed for a longer time than the source gas supply process at the second flow rate.

[Appendix 9]
Also preferably,
The controller is
While varying the flow rate of the source gas by changing the flow rate of the source gas,
A process of performing the supply process of the source gas at the first flow rate a predetermined number of times;
A cycle including at least a predetermined number of cycles of supplying the source gas at the second flow rate a predetermined number of times less than in the case of the first flow velocity.

[Appendix 10]
Also preferably,
A plurality of the source gas nozzles having different diameters of the gas injection ports are provided at the predetermined position in the processing chamber.

[Appendix 11]
Also preferably,
A plurality of the source gas nozzles having different lengths are provided at the predetermined position of the processing chamber.

[Appendix 12]
According to a fifth aspect of the present invention,
A substrate carrying-in step of accommodating a plurality of substrates stacked in a horizontal posture in a processing chamber;
Even if the temperature in the processing chamber is higher than the thermal decomposition temperature of the source gas, a source gas nozzle disposed at a predetermined position in the processing chamber that does not decompose the source gas at a first flow rate. A first source gas supply step for supplying the source gas into the processing chamber;
A second source gas supply step of supplying the source gas into the processing chamber from the source gas nozzle at a second flow rate different from the first flow rate;
A reactive gas supply step of supplying a reactive gas that reacts with the source gas into the processing chamber from a reactive gas nozzle disposed in the processing chamber along the stacking direction of the substrate;
An exhaust process for exhausting the processing chamber in a substantially horizontal direction;
A substrate unloading step of unloading the substrate that has been processed from the processing chamber;
The first source gas supply step, the second source gas supply step, and the reaction gas supply step are defined as one cycle, and this cycle is performed a predetermined number of times to form a predetermined film on the substrate. It is a manufacturing method of an apparatus.

[Appendix 13]
The sixth aspect of the present invention is:
A substrate carrying-in step of accommodating a plurality of substrates stacked in a horizontal posture in a processing chamber;
Even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the source gas, the processing chamber is disposed at a predetermined position below the processing chamber so that the source gas is not decomposed inside, and an upper portion of the processing chamber. A first source gas supply step of supplying the source gas to the substrate accommodated at the lower side of the processing chamber at a first flow rate from a source gas nozzle in which a source gas jet port is opened,
A second source gas supply step of supplying the source gas from the source gas nozzle to the other substrate accommodated on the upper side of the processing chamber at a second flow rate larger than the first flow rate;
A reactive gas supply step of supplying a reactive gas that reacts with the source gas into the processing chamber from a reactive gas nozzle disposed in the processing chamber along the stacking direction of the substrate;
An exhaust process for exhausting the processing chamber in a substantially horizontal direction;
A substrate unloading step of unloading the substrate that has been processed from the processing chamber;
The first source gas supply step, the second source gas supply step, and the reaction gas supply step are defined as one cycle, and this cycle is performed a predetermined number of times to form a predetermined film on the substrate. It is a manufacturing method of an apparatus.

[Appendix 14]
The seventh aspect of the present invention is
A substrate carrying-in step of accommodating a plurality of substrates stacked in a horizontal posture in a processing chamber configured inside the inner tube;
Even when the temperature in the processing chamber is higher than the thermal decomposition temperature of the source gas, the processing chamber is disposed at a predetermined position below the processing chamber so that the source gas is not decomposed inside, and an upper portion of the processing chamber. A first source gas supply step of supplying the source gas to the substrate accommodated at the lower side of the processing chamber at a first flow rate from a source gas nozzle in which a source gas jet port is opened,
A second source gas supply step of supplying the source gas from the source gas nozzle to the other substrate accommodated on the upper side of the processing chamber at a second flow rate larger than the first flow rate;
A reactive gas supply step of supplying a reactive gas that reacts with the source gas into the processing chamber from a reactive gas nozzle disposed in the processing chamber along the stacking direction of the substrate;
A gas exhaust port is formed in a side wall of the inner tube, and a space sandwiched between the outer tube and the inner tube that surrounds the inner tube is exhausted to be substantially horizontal from the source gas jet port to the gas exhaust port. An exhaust process for exhausting the processing chamber while generating a gas flow in a direction;
A substrate unloading step of unloading the substrate that has been processed from the processing chamber;
The first source gas supply step, the second source gas supply step, and the reaction gas supply step are defined as one cycle, and this cycle is performed a predetermined number of times to form a predetermined film on the substrate. It is a manufacturing method of an apparatus.

[Appendix 15]
Preferably,
In the first source gas supply step, the source gas is supplied into the processing chamber at the first flow rate together with an inert gas from an inert gas supply pipe connected to the source gas nozzle,
In the second source gas supply step, the source gas is supplied into the processing chamber at the second flow rate together with the inert gas whose flow rate is increased as compared with the first source gas supply step.

[Appendix 16]
Also preferably,
While changing the flow rate of the source gas, the flow rate of the source gas is different between the first source gas supply step and the second source gas supply step,
The first source gas supply step is performed for a longer time than the second source gas supply step.

[Appendix 17]
Also preferably,
While changing the flow rate of the source gas, the flow rate of the source gas is different between the first source gas supply step and the second source gas supply step,
Performing the first source gas supplying step a predetermined number of times;
A cycle in which the second source gas supply step is performed a predetermined number of times less than the first source gas supply step is performed a predetermined number of times.

[Appendix 18]
The eighth aspect of the present invention is
From a raw material gas nozzle disposed at a predetermined position in the processing chamber so that the raw material gas does not decompose inside even if the temperature in the processing chamber containing the stacked substrates is higher than the thermal decomposition temperature of the raw material gas A first raw material gas supply step of supplying the raw material gas into the processing chamber at a first flow rate; and the raw material gas is supplied from the raw material gas nozzle into the processing chamber at a second flow rate different from the first flow rate. A second source gas supply step for supplying, and a reaction gas supply step for supplying a reaction gas that reacts with the source gas into the processing chamber from a reaction gas nozzle disposed in the processing chamber along the stacking direction of the substrates. Is a semiconductor device having a predetermined film formed by performing this cycle a predetermined number of times.

200 wafer (substrate)
201 Processing chamber 207 Heater (heating unit)
233a Raw material gas nozzle 280 controller

Claims (7)

A processing chamber for stacking and accommodating a plurality of substrates;
A heating unit for heating the processing chamber;
A raw material gas supply unit for supplying a raw material gas into the processing chamber, wherein the raw material gas is not decomposed inside even when a temperature in the processing chamber is higher than a thermal decomposition temperature of the raw material gas. A raw material gas supply unit including a plurality of raw material gas nozzles having different lengths, which are disposed at predetermined positions and supply the raw material gas into the processing chamber;
A reaction gas supply unit for supplying a reaction gas into the processing chamber, the reaction gas supply unit being disposed in the processing chamber and having a reaction gas nozzle for supplying the reaction gas into the processing chamber;
Controlling the heating unit, the source gas supply unit, and the reaction gas supply unit to heat the processing chamber in which a plurality of substrates are stacked and accommodated, and the plurality of source gas nozzles having different lengths A process including supplying the source gas into the processing chamber and supplying the reaction gas from the reaction gas nozzle into the processing chamber is performed a predetermined number of times to form a film on the substrate. A control unit;
A substrate processing apparatus.   The substrate processing apparatus according to claim 1, wherein the reactive gas supply nozzle extends in a stacking direction of the substrates and has a plurality of gas supply ports.   The substrate processing apparatus according to claim 2, wherein the plurality of gas supply ports gradually increase in opening diameter from the upstream side to the downstream side of the reaction gas. An inert gas supply unit connected to the source gas nozzle and the reaction gas nozzle and supplying an inert gas into the processing chamber;
The controller further controls the inert gas supply unit to supply the inert gas to the source gas nozzle at a first flow rate and supply the source gas to the source gas nozzle at a second flow rate. A process of supplying a source gas to the upper part of the processing chamber; supplying the inert gas to the source gas nozzle at a third flow rate less than the first flow rate; and supplying the source gas at the second flow rate to the source material A film is formed on the substrate by performing a predetermined number of cycles including a process of supplying to the gas nozzle and supplying the source gas to the lower portion of the process chamber and a process of supplying the reaction gas to the process chamber. The substrate processing apparatus according to claim 1, configured as described above.   The control unit controls the source gas supply unit, the reaction gas supply unit, and the inert gas supply unit to supply the source gas to the upper portion of the process chamber, and supplies the source gas to the process chamber. 5. The apparatus according to claim 4, wherein the raw material gas or the reactive gas is pushed out by the inert gas when performing at least one of a process of supplying a lower part and a process of supplying the reactive gas into the processing chamber. The substrate processing apparatus as described.   The control unit is configured to control the source gas supply unit, the reaction gas supply unit, and the inert gas supply unit to supply the source gas and the reaction gas to the processing chamber so as not to mix with each other. The substrate processing apparatus in any one of Claims 1-5. Heating a processing chamber in which a plurality of substrates are stacked and accommodated;
Even if the temperature in the processing chamber is higher than the thermal decomposition temperature of the source gas, a plurality of source gas nozzles having different lengths disposed at predetermined positions in the processing chamber so that the source gas is not decomposed inside. Supplying the source gas into the processing chamber;
Supplying a reaction gas into the processing chamber;
A method for manufacturing a semiconductor device, wherein a film is formed on the substrate by performing a predetermined number of cycles including: