JP2010073978A - Method for processing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a substrate, raising a doping speed of nitrogen into a SiO<SB>2</SB>film. <P>SOLUTION: The method for processing a substrate includes: a process of carrying a substrate into a processing chamber provided in a reactor vessel; a process of processing the substrate by supplying and holding gas in a gas holding chamber provided in the reactor vessel, and supplying the held gas into the processing chamber; and a process of taking out the processed substrate from the processing chamber. In the process of processing the substrate, a plurality of baffles, each baffle being provided with a plurality of holes so as to be dispersed in a plane, are stacked in a gas passage of the gas holding chamber in a horizontal posture with a predetermined spacing, and the gas is held at a temperature of its decomposition by respectively arranging each baffle so that the holes of adjacent baffles do not overlap each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing method for processing a substrate.

  With the miniaturization and high performance of semiconductor devices, performance requirements for thin films formed on a substrate are becoming stricter year by year. For example, in a NAND flash memory device or the like, the dielectric constant of the tunnel oxide film formed on the substrate is further increased so as to further suppress the generation of leakage current in the tunnel oxide film and further improve the data retention performance of the device. There is a need to increase it.

In recent years, in order to increase the dielectric constant of the tunnel oxide film, a substrate processing process such as N ₂ O annealing has been performed. In such a substrate processing step, N ₂ O (nitrous oxide) gas or NO (nitrogen monoxide) gas is supplied from a gas supply system into a processing chamber into which a substrate is carried, and the SiO ₂ film formed on the substrate surface is supplied. Nitrogen (N) of several atoms% was doped (added) to form a SiON film in which nitrogen is segregated in the SiO ₂ film (for example, Patent Document 1).
JP-A-9-260363

However, it has been difficult to obtain a high doping rate (a nitrogen doping amount per unit time) in a conventional substrate processing process in which N ₂ O gas is supplied from a gas supply system into a processing chamber into which a substrate is carried. As a result, it took a long time to dope a desired amount of nitrogen into the SiO ₂ film, and it was difficult to increase the productivity of substrate processing. Further, in the conventional substrate processing process in which NO gas is supplied from the gas supply system into the processing chamber into which the substrate is carried in, even if a high processing speed can be obtained, N ₂ O gas is directly supplied onto the substrate. In some cases, the segregation depth of nitrogen differs. As a result, it is necessary to additionally perform an oxidation step for oxidizing the surface of the SiON film in which the SiO ₂ film is doped with nitrogen, which may increase the substrate processing cost.

An object of the present invention is to provide a substrate processing method capable of increasing the doping rate of nitrogen into a SiO ₂ film.

  According to one aspect of the present invention, a step of carrying a substrate into a processing chamber provided in a reaction vessel, and a gas is supplied and retained in a gas retention chamber provided in the reaction vessel. A step of supplying a gas into the processing chamber to process the substrate; and a step of unloading the processed substrate from the processing chamber. In the step of processing the substrate, a plurality of holes are formed in the surface. A plurality of baffle plates provided so as to be dispersed are stacked in a horizontal posture on the gas flow path in the gas retention chamber with a predetermined interval so that the holes of the adjacent baffle plates do not overlap each other. Further, there is provided a substrate processing method in which the respective baffle plates are respectively disposed and the gas is retained at a temperature at which the gas is decomposed.

According to the substrate processing method of the present invention, the doping rate of nitrogen into the SiO ₂ film can be increased.

The inventors conducted intensive research on a method for increasing the doping rate of nitrogen into the SiO ₂ film. Hereinafter, a part of the research results will be described with reference to FIG. 14, FIG. 5, and FIG.

FIG. 14 is a schematic diagram showing a decomposition reaction process of N ₂ O gas supplied into the processing chamber. According to FIG. 14, most of the N ₂ O gas supplied into the processing chamber and heated is decomposed into N ₂ (nitrogen) gas and O ₂ (oxygen) gas after a predetermined time has elapsed. . At that time, NO gas is generated as an intermediate product. The NO gas acts as an influencing factor (active species) that defines the concentration of nitrogen doped in the SiO ₂ film. Note that once the NO gas is generated, it is difficult to return to the N ₂ O gas again, and it is stable as NO gas for a long time.

FIG. 5 is a graph showing a simulation result in which the relationship between the gas residence time and the NO gas molar fraction is verified. The horizontal axis of FIG. 5 (time N 2 _O gas is placed in a heated state) N 2 _O gas residence time indicates (in seconds) and the vertical axis represents the NO gas N _{2 O} gas mole The fraction is shown. The data of N _{2 O} gas heated to ▲ mark 1000 ° C. in the figure, ■ mark data N _{2 O} gas heated to 900 ° C., the N _{2 O} gas mark which has been heated to 800 ° C. ◆ Each of the data is shown. According to FIG. 5, at any temperature between 800 ° C. and 1000 ° C., the longer the residence time, the higher the molar fraction of NO gas in the N ₂ O gas (that is, the amount of NO gas generated increases). I understand). The temperature of the _{N 2} O gas is 800 ° C., as 900 ° C., higher to 1000 ° C., the mole fraction of NO gas _{N 2} O gas is can be seen that high. That is, as the residence time of the N _{2 O} gas in the process chamber is increased or as the heating temperature of the N _{2 O} gas in the process chamber is high, the decomposition of N 2 _O gas is accelerated, the amount of NO gas increases I understand that. In particular, when N ₂ O gas is heated to 1000 ° C., the production time of NO gas is dramatically increased by securing a residence time of about 10 seconds as compared with the cases of 800 ° C. and 900 ° C. You can see that

FIG. 13 is a graph showing the measurement results on the relationship between the doping depth of nitrogen in the SiO ₂ film and the amount of segregation. The horizontal axis in FIG. 13 indicates the depth (nm) from the surface of the SiO ₂ film, and the vertical axis indicates the nitrogen concentration (atomic%) in the SiO ₂ film. Curve (a) in the figure shows data of N ₂ O gas heated to 1000 ° C., curve (b) shows data of N ₂ O gas heated to 950 ° C., and curve (c) heats up to 900 ° C. Each of the N ₂ O gas data is shown. In any of the curves (a) to (c), the supply flow rate of N ₂ O gas onto the SiO ₂ film was 10 slm, and the supply time was 35 minutes. According to FIG. 13, as the heating temperature of the N ₂ O gas increases to 900 ° C., 950 ° C., and 1000 ° C., the concentration of nitrogen in the SiO ₂ film increases (that is, the doping rate increases). I understand. At any temperature of 900 ° C. to 1000 ° C., nitrogen is segregated to a depth of about 10 to 18 nm from the surface of the SiO ₂ film, and the depth at which the amount of segregation is maximized hardly changes.

From the above verification results, it is effective for the inventors to promote the decomposition of N ₂ O gas and increase the generation amount of NO gas in order to increase the doping rate of nitrogen into the SiO ₂ film. the, N 2 _O gas residence time (N 2 _{times O} gas is placed in a heated state) is extended to obtain a knowledge that it is effective to promote the heating of the N 2 _O gas. Further, the inventors supply N ₂ O gas in a gas retention chamber provided in the reaction vessel and retain it, and supply the retained N ₂ O gas into the processing chamber to process the substrate. Knowledge that it is possible to extend the residence time of the N ₂ O gas and promote the heating of the N ₂ O gas by providing a baffle plate or the like that promotes the residence of the N ₂ O gas on the gas flow path in the residence chamber. Got. The present invention is based on such knowledge obtained by the inventors.

<One Embodiment of the Present Invention>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a reaction vessel provided in a substrate processing apparatus according to an embodiment of the present invention, and FIG. 2 is an enlarged longitudinal sectional view of a gas supply unit provided in the substrate processing apparatus according to an embodiment of the present invention. FIG. 3 is a horizontal sectional view of a reaction vessel provided in the substrate processing apparatus according to one embodiment of the present invention, and FIG. 4 is a gas supply unit provided in the substrate processing apparatus according to one embodiment of the present invention. FIG. 12 is a schematic configuration diagram of a substrate processing apparatus according to an embodiment of the present invention.

(1) Configuration of Substrate Processing Apparatus First, a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 12, the substrate processing apparatus 101 according to the present embodiment includes a housing 111. A cassette stage 114 is provided on the front side inside the casing 111. The cassette stage 114 is configured to exchange a cassette (pod) 110 as a substrate storage container for storing the wafer 25 as a substrate with an external transfer device (not shown). A cassette elevator 118 is provided on the rear side of the cassette stage 114 as an elevating means for moving the cassette 110 up and down. The cassette elevator 118 is provided with a cassette transfer machine 118b as a conveying means for moving the cassette 110 horizontally. Further, a cassette shelf 118 a as a means for placing the cassette 110 is provided on the rear side of the cassette elevator 118. A transfer shelf 123 is provided on the cassette shelf 118a. On the transfer shelf 123, a cassette 110 that accommodates a substrate to be processed and a substrate after processing is temporarily placed. Further, a spare cassette shelf 107 as a mounting means for the cassette 110 is provided above the cassette stage 114. A clean unit 134 a that circulates clean air inside the casing 111 is provided above the spare cassette shelf 107.

  Above the rear part of the casing 111, a cylindrical processing furnace 5 having a lower end opened is provided vertically. The detailed configuration of the processing furnace 5 will be described later.

  Below the processing furnace 5, a boat elevator 115 as an elevating means is provided. A lift board 252 is provided at the lower end of the boat elevator 115. On the elevating substrate 252, the boat 3 as a substrate holding means is vertically attached through a seal cap 26 as a lid. When the boat elevator 115 is raised, the boat 3 is carried into the processing furnace 5 and the lower end opening (furnace port) of the processing furnace 5 is hermetically sealed by the seal cap 26. . Further, a furnace port shutter 147 as a closing means is provided beside the lower end portion of the processing furnace 5. The furnace port shutter 147 is configured to hermetically close the lower end portion of the processing furnace 5 while the boat elevator 115 is descending.

  Between the processing furnace 5 and the cassette shelf 118a, a transfer elevator 125b is provided as a lifting means for moving the wafer 25 up and down. A wafer transfer machine 112 as a transfer means for horizontally moving the wafer 25 is attached to the transfer elevator 125b.

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

  First, the cassette 110 loaded with the wafers 25 is transferred by an external transfer device (not shown) and placed on the cassette stage 114. At this time, the wafer 25 is placed in a vertically oriented posture. Thereafter, when the cassette stage 114 is rotated by 90 °, the surface of the wafer 25 faces upward from the substrate processing apparatus 101, and the wafer 25 is in a horizontal posture.

Thereafter, the cassette 110 is moved from the cassette stage 114 to the cassette shelf 118a or the spare cassette shelf 107 by a coordinated operation of the raising / lowering operation and horizontal operation of the cassette elevator 118 and the advance / retreat operation and rotation operation of the cassette transfer machine 118b. It is conveyed. Thereafter, the cassette 110 to be transferred to the wafer 25 is transferred onto the transfer shelf 123 by the cooperative operation of the cassette elevator 118 and the cassette transfer machine 118b.

  Thereafter, the wafer 25 loaded in the cassette 110 on the transfer shelf 123 is moved down by the cooperative operation of the advance / retreat operation and rotation operation of the wafer transfer device 112 and the raising / lowering operation of the transfer elevator 125b. 3 is transferred (loaded).

  Thereafter, when the boat elevator 115 is raised, the boat 3 is carried into the processing furnace 5 and the inside of the processing furnace 5 is hermetically sealed by the seal cap 26. Then, the wafer 25 is heated in the processing furnace 5 that is hermetically closed and decompressed, and gas is supplied into the processing furnace 5, whereby a predetermined process is performed on the surface of the wafer 25. Details of such processing will be described later.

  When the processing on the wafer 25 is completed, the boat 3 is unloaded from the inside of the processing furnace 5 by a procedure reverse to the above-described procedure, and the processed wafer 25 is transferred from the boat 3 to the cassette 110 on the transfer shelf 123. It is transferred in. Then, the cassette 110 storing the processed wafer 25 is transferred from the transfer shelf 123 to the cassette stage 114 by the cassette transfer device 118b, and is moved outside the casing 111 by an external transfer device (not shown). Be transported. Note that after the boat elevator 115 is lowered, the furnace port shutter 147 airtightly closes the lower end portion of the processing furnace 5 to prevent outside air from entering the processing furnace 5.

(3) Configuration of Processing Furnace Next, the configuration of the processing furnace 5 according to the present embodiment will be described with reference to FIGS.

(Processing room)
As shown in FIG. 1, the processing furnace 5 includes a reaction vessel 6 mainly composed of a reaction tube 6a and a manifold 6b. The reaction tube 6a is made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with the upper end closed and the lower end open. The manifold 6b is made of, for example, a metal material such as SUS, and has a cylindrical shape with an upper end portion and a lower end portion opened. The reaction tube 6a is supported vertically from the lower end side by the manifold 6b. The reaction tube 6a and the manifold 6b are arranged concentrically. The lower end portion of the manifold 6b is configured to be hermetically sealed by the seal cap 26 when the boat elevator 115 described above rises. Sealing members such as O-rings are provided between the reaction tube 6a and the manifold 6b and between the manifold 6b and the seal cap 26, respectively.

  In the reaction vessel 6, a processing chamber 11 into which a wafer 25 as a substrate is carried is formed. A boat 3 as a substrate holder is inserted into the processing chamber 11 from below. The inner diameters of the reaction tube 6 a and the manifold 6 b are configured to be larger than the maximum outer shape of the boat 3 loaded with the wafers 25.

The boat 3 is configured to hold a plurality of (for example, 75 to 100) wafers 25 in multiple stages with a predetermined gap (substrate pitch interval) in a substantially horizontal state. The boat 3 is mounted on a heat insulating cap 3a that blocks heat conduction. The heat insulating cap 3 a is supported from below by the rotating shaft 16. The rotary shaft 16 is provided so as to penetrate the center portion of the seal cap 26. A rotation mechanism (not shown) that rotates the rotation shaft 16 is provided below the seal cap 26. By rotating the rotating shaft 16 by a rotating mechanism, the boat 3 on which a plurality of wafers 25 are mounted can be rotated while maintaining the airtightness in the processing chamber 11.

(heater)
A heater 15 as a heating means (heating mechanism) is provided on the outer periphery of the reaction vessel 6 concentrically with the reaction vessel 6. The heater 15 has a cylindrical shape and is vertically installed by being supported by a heater base (not shown) as a holding plate. At the upper end portion of the heater 15, a lid-like heat insulating material that increases the heating efficiency inside the heater 15 is provided.

(Gas supply system)
A gas introduction pipe 10 serving as a gas supply system for supplying gas into the reaction vessel 6 is connected to the ceiling of the reaction tube 6a. The gas introduction pipe 10 is arranged in the vertical direction between the heater 15 and the reaction vessel 6 so as to follow the side wall of the reaction vessel 6. On the upstream side of the gas introduction pipe 10, and N _{2 O} gas supply pipe 10a for supplying the N _{2 O} gas as at least a nitriding gas, oxygen as oxidizing (O ₂₎ gas containing gas oxidizing gas supply pipe 10b for supplying the Are connected to an inert gas supply pipe 10c for supplying nitrogen (N ₂ ) gas as an inert gas. The N ₂ O gas supply pipe 10a, in order from an upstream side, and supplies the _{N 2} O gas _{N 2} O gas supply source (not shown), the opening and closing valve 8a, the mass flow controller (MFC) 9a is provided. The oxidizing gas supply pipe 10b is provided with an oxidizing gas supply source (not shown) for supplying oxygen (O ₂ ) -containing gas, an open / close valve 8b, and a mass flow controller (MFC) 9b in order from the upstream side. The inert gas supply pipe 10c is provided with an inert gas supply source (not shown) for supplying an inert (N ₂ ) gas, an open / close valve 8c, and a mass flow controller (MFC) 9c in order from the upstream side. .

(Gas retention chamber)
A gas supply unit 7 configured as a shower head is provided in a ceiling portion (portion A in FIG. 1) in the reaction tube 6a to which the gas introduction pipe 10 is connected. The gas supply unit 7 is made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with an upper end and a lower end opened. The upper end of the gas supply unit 7 is airtightly connected to the ceiling wall in the reaction tube 6a. A shower plate 20 provided with a plurality of vent holes 20a dispersed in the plane is provided at the lower end of the gas supply unit 7 so as to hermetically close the lower end opening of the gas supply unit 7. . The hole diameter, the number of holes, the arrangement interval, and the like of the plurality of vent holes 20a are adjusted so that the flow rate of the gas supplied to the wafer 25 carried into the processing chamber 11 is uniform. In the space surrounded by the ceiling wall in the reaction tube 6 a, the inner wall of the gas supply unit 7, and the shower plate 20, the gas supplied from the gas introduction pipe 10 is retained, and the retained gas is supplied into the processing chamber 11. A gas retention chamber 21 is formed.

As shown in FIG. 2, the first baffle plate 17 and the second baffle plate 18 are stacked in a horizontal posture at a predetermined interval on the gas flow path in the gas retention chamber 21. The first baffle plate 17 and the second baffle plate 18 are made of a heat-resistant non-metallic material such as quartz (SiO ₂ ) or silicon carbide (SiC), and are configured in a disc shape. The outer peripheral portions of the first baffle plate 17 and the second baffle plate 18 are airtightly connected to the inner wall of the gas supply unit 7. Accordingly, the gas staying chamber 21 is divided into the first staying chamber R1 sandwiched between the ceiling wall in the reaction tube 6a and the first baffle plate 17, the first baffle plate 17 and the second baffle plate 18. The region is divided into three regions: a second staying chamber R2 sandwiched between, and a third staying chamber R3 sandwiched between the second baffle plate 18 and the shower plate 20.

The first baffle plate 17 is provided with a plurality of vent holes 17a so as to be dispersed in the plane, and the second baffle plate 18 is provided with a plurality of vent holes 18a so as to be dispersed in the plane. Is provided. The holes of adjacent baffle plates are arranged so as not to overlap each other. That is, the vent hole 17a of the first baffle plate 17 and the vent hole 18a of the second baffle plate 18 are arranged so as not to overlap each other when viewed from above (not arranged in a straight line). Further, the vent holes 18a of the second baffle plate 18 and the vent holes 20a of the shower plate 20 are also arranged so as not to overlap each other when viewed from above (not arranged in a straight line).

  For example, the vent holes 17a, the vent holes 18a, and the vent holes 20a can be arranged radially and staggered on the first baffle plate 17, the second baffle plate 18, and the shower plate 20, respectively. In such a case, the first baffle plate 17 and the second baffle plate 18 are arranged so as to be shifted in the circumferential direction while the second baffle plate 18 and the shower plate 20 are shifted in the circumferential direction. By rotating and arranging the air holes 17a and 18b, the air holes 17a and 18a do not overlap with each other when viewed from above, and the air holes 18a and 20a do not overlap. Such a situation is shown in FIGS. Note that the vents 17a, 18a, and 20a are arranged in a radial pattern as shown in FIG. 3 unless the vents 17a and 18a overlap and the vents 18a and 20a do not overlap. And it is not limited to the staggered arrangement.

  The gas supplied from the gas introduction pipe 10 into the gas residence chamber 21 flows into the first residence chamber R1 sandwiched between the ceiling wall in the reaction tube 6a and the first baffle plate 17 and stays for a certain period of time. Then, the air flows into the second staying chamber R2 sandwiched between the first baffle plate 17 and the second baffle plate 18 through the vent hole 17a and stays for a certain period of time, and then the second baffle through the vent hole 18a. It flows into the third retention chamber R3 sandwiched between the plate 18 and the shower plate 20, stays for a certain period of time, and flows into the processing chamber 11 through the vent hole 20a. At this time, when the gas supplied into the gas retention chamber 21 passes through the first retention chamber R1, the second retention chamber R2, and the third retention chamber R3, the radiant heat from the heater 15 and the inner wall of the gas supply section 7 The first baffle plate 17, the second baffle plate 18, and the shower plate 20 are configured to be heated by heat transfer.

  At this time, the flow of the first baffle plate 17, the second baffle plate 18, and the shower plate 20 provided on the gas flow path causes the inside of the first stay chamber R 1, the second stay chamber R 2, and the third stay chamber R 3. The pressure of the gas increases greatly, and the flow rate of the gas decreases as the pressure increases. Specifically, the relationship among the pressure P1 in the first residence chamber R1, the pressure P2 in the second residence chamber R2, the pressure P3 in the third residence chamber R3, and the pressure Pr in the processing chamber 11 is: P1> P2> P3> Pr. In addition, the flow velocity V1 of the gas in the first retention chamber R1, the flow velocity V2 of the gas in the second retention chamber R2, the flow velocity V3 of the gas in the third retention chamber R3, and the flow velocity Vr of the gas in the processing chamber 11. The relationship is such that V1 <V2 <V3 <Vr.

  In the above, if the relationship is other than P1> P2> P3> Pr (for example, P1> P3> P2> Pr), the gas supplied from the gas introduction pipe 10 into the gas retention chamber 21 is in the processing chamber 11. It becomes difficult to flow to. Therefore, it is preferable to satisfy P1> P2> P3> Pr as described above. Note that the pressure values of P1, P2, P3, and Pr can be adjusted as appropriate according to the hole diameter, the number of holes, the arrangement interval, the gas flow rate, and the like of the vent hole 17a, the vent hole 18a, and the vent hole 20a.

Further, the arrangement of the air holes 17a, the air holes 18a, and the air holes 20a is such that the air holes 17a and the air holes 18a do not overlap with each other, and the air holes 18a and the air holes 20a do not overlap with each other. , It becomes difficult for the N ₂ O gas to pass smoothly through the gas retention chamber 21 (in a straight line), the gas retention time in the gas retention chamber 21 becomes longer, and the second residence time in the first retention chamber R1 Generation of gas vortex (convection) 19 is promoted in the chamber R2 and the third residence chamber R3. Then, the contact between the spiral gas supplied into the gas retention chamber 21 and the inner wall of the gas retention chamber 21, which is also a heat source, the first baffle plate 17, the second baffle plate 18, the shower plate 20, and the like is promoted. It is comprised so that the heating of the gas by heat transfer may be accelerated | stimulated.

(Gas exhaust system)
An exhaust pipe 12 serving as an exhaust system for exhausting the atmosphere in the processing chamber 11 is connected to the side wall of the manifold 6b. The exhaust pipe 12 is provided with a conductance variable valve 13 as a pressure regulator and a vacuum pump 14 as a vacuum exhaust device in order from the upstream side. By adjusting the opening degree of the open / close valve of the conductance variable valve 13 while operating the vacuum pump 14, the inside of the processing chamber 11 can be set to a desired pressure.

(controller)
The substrate processing apparatus 101 includes a controller 280 as a control unit (control unit). The controller 280 is connected to the heater 15, the conductance variable valve 13, the vacuum pump 14, the rotation mechanism, the boat elevator 115, the open / close valves 8a to 8c, the mass flow controllers 9a to 9c, and the like. The controller 280 adjusts the temperature of the heater 15, opens / closes the conductance variable valve 13, and adjusts the pressure, starts / stops the vacuum pump 14, adjusts the rotation speed of the rotating mechanism, lifts / lowers the boat elevator 115, and opens / closes the valves 8 a to 8 c. Control such as opening / closing operation and flow rate adjustment of the mass flow controllers 9a to 9c is performed.

(4) Substrate Processing Step Subsequently, as one step of the semiconductor device manufacturing process according to the present embodiment, an oxide film forming step of forming an SiO ₂ film as an oxide film on the surface of the wafer 25, and nitrogen in the SiO ₂ film A substrate processing step having an N ₂ O annealing step of adding (doping) will be described. In the following description, the operation of each unit included in the substrate processing apparatus 101 is controlled by the controller 280.

(Substrate loading process)
First, a plurality of wafers 25 to be processed are loaded into the lowered boat 3 by the wafer transfer device 112. When the loading of the predetermined number of wafers 25 is completed, the boat 3 holding the predetermined number of wafers 25 is loaded into the processing chamber 11 by the boat elevator 115 (boat loading), and the furnace port which is the lower end opening of the processing furnace 5 Is closed by a seal cap 26.

Then, the vacuum pump 14 is operated to exhaust the processing chamber 11 from the exhaust pipe 12. At this time, the opening / closing valve 8c is opened, and N ₂ gas as an inert gas is supplied from the gas introduction pipe 10 into the reaction vessel 6 while controlling the flow rate by the mass flow controller 9c. Further, the opening degree of the open / close valve of the conductance variable valve 13 is adjusted so that the inside of the processing chamber 11 has a desired pressure. The N ₂ gas supplied from the gas introduction pipe 10 into the gas retention chamber 21 flows into the processing chamber 11 through the vent hole 20 a of the shower plate 20, and is discharged out of the processing chamber 11 through the exhaust pipe 12.

  Then, the amount of current supplied to the heater 15 is adjusted, and the temperature inside the reaction vessel 6 is increased until a predetermined process temperature is reached. For example, the energization amount to the heater 15 is adjusted so that the temperature of the surface of the wafer 25 is in the range of 900 ° C. to 1000 ° C., for example, 1000 ° C. At this time, the inner wall of the gas supply unit 7, the first baffle plate 17, the second baffle plate 18, and the shower plate 20 are also heated. Then, based on the temperature information detected by a temperature sensor (not shown), feedback control of the power supply to the heater 15 is performed so that the reaction container 6 has a desired temperature distribution.

  Subsequently, the rotating shaft 16 of the rotating mechanism is rotated, and the boat 3 and the wafer 25 are rotated.

(Oxide film formation process)
Next, the opening / closing valve 8b is opened, and the supply of oxygen (O ₂ ) -containing gas as the oxidizing gas from the gas introduction pipe 10 into the reaction vessel 6 is started while the flow rate is controlled by the mass flow controller 9b. At this time, the on-off valve 8c is closed, and the supply of the inert gas into the reaction vessel 6 is stopped. The oxygen-containing gas supplied from the gas introduction pipe 10 into the gas retention chamber 21 flows into the processing chamber 11 through the vent holes 20 a of the shower plate 20 and is supplied onto the surface of the wafer 25 held by the boat 3. After that, the gas is discharged from the exhaust pipe 12 to the outside of the processing chamber 11. After a predetermined time has elapsed, the open / close valve 8b is closed, and the supply of the oxygen-containing gas into the reaction vessel 6 is stopped. As a result, an oxide film (SiO ₂ film) having a predetermined thickness is formed on the surface of the wafer 25.

(N ₂ O annealing process)
Next, the opening / closing valve 8a is opened, and the supply of N ₂ O gas as the nitriding gas from the gas introduction pipe 10 into the reaction vessel 6 is started while the flow rate is controlled by the mass flow controller 9a.

The N ₂ O gas supplied from the gas introduction pipe 10 into the gas retention chamber 21 flows into the first retention chamber R1 sandwiched between the ceiling wall in the reaction tube 6a and the first baffle plate 17 and is constant. It stays for a period of time, flows into the second staying chamber R2 sandwiched between the first baffle plate 17 and the second baffle plate 18 through the vent hole 17a, stays for a certain period of time, and stays for a certain period of time through the vent hole 18a. Flows into the third retention chamber R3 sandwiched between the two baffle plates 18 and the shower plate 20, stays for a certain time, and flows into the processing chamber 11 through the vent hole 20a. At this time, when the N ₂ O gas supplied into the gas retention chamber 21 passes through the first retention chamber R1, the second retention chamber R2, and the third retention chamber R3, the radiation heat from the heater 15 and the gas supply It is heated and decomposed by heat transfer from the inner wall of the section 7, the first baffle plate 17, the second baffle plate 18, and the shower plate 20, and NO gas as an intermediate product is generated. N ₂ O gas containing NO gas is supplied onto the surface of the wafer 25 held by the boat 3 and then discharged out of the processing chamber 11 through the exhaust pipe 12. As a result, a predetermined amount of nitrogen is doped (added) into the SiO ₂ film formed on the surface of the wafer 25.

At this time, the flow of the first baffle plate 17, the second baffle plate 18, and the shower plate 20 provided on the gas flow path causes the inside of the first stay chamber R 1, the second stay chamber R 2, and the third stay chamber R 3. The pressure of the gas greatly increases, and the gas flow rate decreases as the pressure increases. Specifically, the relationship among the pressure P1 in the first residence chamber R1, the pressure P2 in the second residence chamber R2, the pressure P3 in the third residence chamber R3, and the pressure Pr in the processing chamber 11 is: P1>P2>P3> Pr. In addition, the flow velocity V1 of the gas in the first retention chamber R1, the flow velocity V2 of the gas in the second retention chamber R2, the flow velocity V3 of the gas in the third retention chamber R3, and the flow velocity Vr of the gas in the processing chamber 11. Is V1 <V2 <V3 <Vr. As a result, the residence time of the N ₂ O gas supplied into the gas residence chamber 21 is extended, and the decomposition time of the N ₂ O gas is sufficiently ensured. In addition, by extending the residence time, a sufficient heating time is ensured, and decomposition of the N ₂ O gas is promoted. Then, the amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) increases, and the doping rate of nitrogen into the SiO ₂ film is accelerated.

Further, the arrangement of the air holes 17a, the air holes 18a, and the air holes 20a is configured such that the air holes 17a and the air holes 18a do not overlap with each other, and the air holes 18a and the air holes 20a do not overlap with each other. For this reason, it becomes difficult for the N ₂ O gas to smoothly pass through the gas retention chamber 21 (in a straight line), and N ₂ O gas in the first retention chamber R1, the second retention chamber R2, and the third retention chamber R3. Generation of a vortex (convection) 19 of ₂ O gas is promoted. Then, the contact between the spiral N ₂ O gas supplied into the gas retention chamber 21 and the inner wall of the gas retention chamber 21, which is also a heat source, the first baffle plate 17, the second baffle plate 18, the shower plate 20, etc. The N ₂ O gas is heated by heat transfer. As a result, decomposition of the N ₂ O gas is promoted, the amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) increases, and the doping rate of nitrogen into the SiO ₂ film Is accelerated.

After a predetermined time has elapsed, the on-off valve 8a is closed, and the supply of N ₂ O gas into the reaction vessel 6 is stopped.

In order to increase the amount of NO gas supplied to the wafer 25, it is preferable to increase the pressure in the gas retention chamber 21 as a whole in the N ₂ O annealing step. That is, it is preferable to set the pressure value so that (P1 + P2 + P3) / 3 is maximized and the gas supply unit 7 is not damaged. The pressure in the gas retention chamber 21 can be appropriately adjusted according to the hole diameter, the number of holes, the arrangement interval, the flow rate of N ₂ O gas, and the like of the vent hole 17a, the vent hole 18a, and the vent hole 20a.

(Substrate unloading process)
Next, the open / close valve 8c is opened, and the open / close valve of the conductance variable valve 13 is opened while N ₂ gas is supplied from the gas introduction pipe 10 into the reaction vessel 6 to replace the atmosphere in the reaction vessel 6 with N ₂ gas. The pressure in the reaction vessel 6 is returned to atmospheric pressure by adjusting the degree. Then, the processed wafer 25 is unloaded from the reaction vessel 6 by a procedure reverse to the above-described substrate loading step, and the substrate processing step according to the present embodiment is completed.

(5) Effect According to the present embodiment, one or a plurality of effects are obtained from the following (a) to (h).

(A) According to this embodiment, the first baffle plate 17 and the second baffle plate 18 are provided on the gas flow path in the gas retention chamber 21. As a result, the pressure in the first residence chamber R1, the second residence chamber R2, and the third residence chamber R3 can be greatly increased, and the gas flow rate can be reduced. Then, to extend the residence time of the N _{2 O} gas supplied to the gas residence chamber 21, the degradation time of the N 2 _O gas can be sufficiently secured. In addition, by prolonging the residence time, heating time N 2 _O gas can be sufficiently ensured, the decomposition of N 2 _O gas can be promoted. The amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) can be increased, and the doping rate of nitrogen into the SiO ₂ film can be increased.

(B) According to the present embodiment, the arrangement of the air holes 17a, the air holes 18a, and the air holes 20a is such that the air holes 17a and 18a do not overlap, and the air holes 18a and 20a do not overlap. It is configured as follows. As a result, it is difficult for the N ₂ O gas to pass smoothly (linearly) through the gas retention chamber 21, and into the first retention chamber R1, the second retention chamber R2, and the third retention chamber R3. Thus, the generation of vortex (convection) 19 of N ₂ O gas can be promoted. Then, contact between the spiral N ₂ O gas supplied into the gas retention chamber 21 and the inner wall of the gas retention chamber 21, which is also a heat source, the first baffle plate 17, the second baffle plate 18, the shower plate 20, etc. The surface area of contact with the heat source can be increased and the heating of the gas by heat transfer can be promoted. As a result, encourage the decomposition of N 2 _O gas, NO gas amount supplied to the wafer 25 (mole fraction of NO gas N 2 _O gas) increases, without substantially raising the temperature of the heater The doping rate of nitrogen into the SiO ₂ film can be increased.

For reference, the structure of a conventional substrate processing apparatus is shown in FIGS. FIG. 9 is a longitudinal sectional view of a processing furnace provided in a conventional substrate processing apparatus. FIG. 10 is a horizontal sectional view of a processing furnace provided in a conventional substrate processing apparatus. FIG. 11 is an enlarged vertical cross-sectional view of a gas supply unit provided in a conventional substrate processing apparatus. According to FIGS. 9 to 10, the first baffle plate 17 and the second baffle plate 18 are not provided inside the gas supply unit 7 included in the conventional substrate processing apparatus. Therefore, there is a tendency that the pressure in the gas supply unit 7 does not increase and the gas flow rate does not decrease sufficiently. Then, the residence time of the N ₂ O gas in the gas supply unit 7 is insufficient and the decomposition of the N ₂ O gas becomes insufficient, or the heating of the N ₂ O gas is insufficient and the decomposition of the N ₂ O gas is not possible. Sometimes it was enough. Further, there have been cases where the gas retaining chamber 21 N _{2 O} gas is smoothly (linearly) easily passes through the heating of the N 2 _O gas is insufficient decomposition of N _{2 O} gas becomes insufficient. For this reason, it has been difficult to obtain a high processing speed (a doping speed of nitrogen into the SiO ₂ film).

(C) According to the present embodiment, the process temperature is the same in the oxide film forming step and the N ₂ O annealing step. That is, the surface of the wafer 25 is heated to the same temperature within the range of 900 ° C. to 1000 ° C. (for example, 1000 ° C.) in both the oxide film forming step and the N ₂ O annealing step. Accordingly, there is no waiting time for changing the temperature (process temperature) of the surface of the wafer 25 when shifting from the oxide film forming process to the N ₂ O annealing process, and the oxide film forming process and the N ₂ O annealing process are performed. Can be carried out continuously. As a result, the substrate processing time can be shortened and the productivity of the substrate processing can be improved as compared with the conventional substrate processing step.

(D) According to the present embodiment, the heating of the N ₂ O gas is promoted as described above, and the decomposition of the N ₂ O gas is promoted, so that the use efficiency of the N ₂ O gas is improved. As a result, the amount of N ₂ O required for performing the N ₂ O annealing step can be reduced, and the substrate processing cost can be reduced.

(E) According to the present embodiment, the gas retention chamber 21 that decomposes N ₂ O gas to generate NO gas is provided in the reaction vessel 6. As a result, compared with the case where an apparatus for generating NO gas is provided outside the reaction vessel 6, the distance between the NO gas generation location and the wafer 25 can be reduced, and the generated NO gas can be reduced in a very short time. Can be supplied on top. For this reason, it is possible to suppress the generated NO gas from being deactivated before it arrives on the wafer 25, and the substrate processing efficiency can be increased. For example, it is possible to obtain a SiON film in which a SiO ₂ film contains nitrogen of 2.5 atoms% or more which is also a target value.

(F) According to the present embodiment, the above-described effect is obtained by providing the first baffle plate 17 and the second baffle plate 18 in the gas retention chamber 21. For example, the gas heating means is newly installed. There is no need to add or greatly change the structure of the heater 15 or the reaction vessel 6. In addition, according to the present embodiment, any gas of oxygen-containing gas and N ₂ O gas can be introduced into the reaction vessel 6 using the gas introduction pipe 10 in common. That is, according to this embodiment, it is not necessary to greatly change the configuration of the conventional substrate processing apparatus, and most of the conventional substrate processing apparatus can be used, reducing the cost of the substrate processing apparatus, Costs can be reduced.

(G) According to the present embodiment, the number of baffle plates provided in the gas retention chamber 21, the thickness of the baffle plates, the diameter of the vent holes provided in the baffle plates and the shower plate 20, the number of holes, and the arrangement interval are appropriately adjusted. Thus, the residence time of the N ₂ O gas in the gas residence chamber 21 can be varied, the molar fraction of the NO gas in the N ₂ O gas can be freely controlled, and the nitrogen doping rate can be adjusted. In addition, since the substrate processing apparatus which supplies gas via the gas supply part 7 comprised as a shower head can install a baffle plate in the gas supply part 7 like this embodiment, a nozzle The present invention can be applied more suitably than a substrate processing apparatus that supplies a gas through the substrate.

(H) According to the present embodiment, not only the NO gas is supplied onto the wafer 25, but N ₂ O gas containing NO gas is supplied. According to the inventor's knowledge, when N ₂ O gas is decomposed, O ₂ (oxygen) gas, O ^* (active species) and the like are generated, and by these actions, nitrogen doped in the SiO ₂ film is formed. It becomes easy to segregate. As a result, it is not necessary to additionally perform an oxidation step for oxidizing again the surface of the SiON film in which the SiO ₂ film is doped with nitrogen, and the substrate processing cost can be reduced. As described above, in the conventional substrate processing process in which NO gas is directly supplied, the segregation depth of nitrogen is different from that in the case of supplying N ₂ O gas directly on the substrate (for example, it becomes shallower). There was a case. As a result, it is necessary to additionally perform an oxidation step for oxidizing the surface of the SiON film in which the SiO ₂ film is doped with nitrogen, which may increase the substrate processing cost.

<Other Embodiments of the Present Invention>
Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a longitudinal sectional view of a processing furnace provided in a substrate processing apparatus according to another embodiment of the present invention. FIG. 8 is an enlarged vertical cross-sectional view of a gas supply unit provided in a substrate processing apparatus according to another embodiment of the present invention.

  In the gas retention chamber 21 according to the above-described embodiment, the first baffle plate 17 and the second baffle plate 18 are stacked in a horizontal posture at a predetermined interval. On the other hand, in the present embodiment, the first baffle plate 17 and the second baffle plate 18 are not provided in the gas retention chamber 21, and the flow resistor 24 is filled. Is different. Other configurations are the same as those of the above-described embodiment.

  The flow resistor 24 is made of, for example, a ceramic material such as oxide, carbide, nitride, or boride, and is formed in a bead shape or a cullet shape. By filling the gas retention chamber 21 with the flow resistor 24, a porous (porous) vent hole (gas flow path) is formed in the gas retention chamber 21.

According to the present embodiment, when the N ₂ O gas supplied into the gas retention chamber 21 passes through the porous vent (gas flow path), the gas flow rate is reduced, and the residence time is extended, A sufficient decomposition time of the N ₂ O gas can be secured. Further, since the residence time is prolonged, the heating time of the N 2 _O gas can be sufficiently ensured, the decomposition of N 2 _O gas can be promoted. The amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) can be increased, and the doping rate of nitrogen into the SiO ₂ film can be increased.

Further, according to the present embodiment, the heating of the N ₂ O gas can be promoted by the heat transfer effect from the inner wall of the gas retention chamber 21 that is also a heat source and the flow resistor 24. As a result, the decomposition of the N ₂ O gas is promoted, the amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) is increased, and the doping rate of nitrogen into the SiO ₂ film is increased. Can be increased.

Further, in the present embodiment, by adjusting the particle size and filling amount of the flow resistor 24, the residence time of the N ₂ O gas can be adjusted freely, the residence time etc. can be varied, and the N ₂ O gas It is possible to adjust the nitrogen doping rate by freely controlling the molar fraction of NO gas. However, the particle size of the flow resistor 24 is preferably set to such a size that the flow resistor 24 does not fall from the vent hole 20a, for example, about 1 mm to 10 mm. The flow resistor 24 is shaped as shown in FIGS. 7 and 8 as long as a porous vent hole (gas flow path) is formed in the gas retention chamber 21 by filling the flow resistor 24. The shape is not limited to a spherical shape, and may be any shape.

  In the present embodiment, the first baffle plate 17 and the second baffle plate 18 may be provided. And it is good also as filling the flow resistance body 24 in all the 1st residence chamber R1, 2nd residence chamber R2, and 3rd residence chamber R3, 1st residence chamber R1, 2nd residence chamber R2, 3rd residence chamber. The flow resistor 24 may be filled only in a part of the chamber R3. Thereby, it becomes possible to synergistically exhibit the effect exhibited in each embodiment.

<Still another embodiment of the present invention>
Next, another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a longitudinal sectional view of a processing furnace provided in a substrate processing apparatus according to another embodiment of the present invention.

  The gas introduction pipe 10 according to the above-described embodiment is disposed vertically (in a straight line) between the heater 15 and the reaction vessel 6 so as to be along the side wall of the reaction vessel 6. On the other hand, the gas introduction pipe 10 according to the present embodiment is arranged so as to wrap around the side wall of the reaction vessel 6 between the heater 15 and the reaction vessel 6. Other configurations are the same as those of the above-described embodiment.

According to the present embodiment, the N ₂ O gas supplied into the reaction vessel 6 is sufficiently preheated by flowing through the gas introduction pipe 10 arranged to wrap around the side wall of the reaction vessel 6. . As a result, the decomposition of N ₂ O gas in the gas retention chamber 21 is further promoted, the amount of NO gas supplied to the wafer 25 (the molar fraction of NO gas in the N ₂ O gas) is further increased, and SiO ₂ The nitrogen doping rate into the film can be further increased.

<Still another embodiment of the present invention>
In the above-described embodiment, the configuration in which two baffle plates are provided in the gas retention chamber 21 has been described. However, the present invention is not limited to such a configuration, and a single baffle plate may be provided in the gas retention chamber 21. Alternatively, three or more may be provided.

In the embodiment described above, the addition of nitrogen to the SiO ₂ film (doped) to N _{2 O} anneal step, had an be performed after the oxide film formation step of forming a SiO ₂ film, the present invention is to such an order It is not limited. For example, the wafer 25 on which the oxide film has been formed in advance may be carried into the reaction vessel 6 and the N ₂ O annealing step may be performed without performing the oxide film formation step. Further, the present invention can be suitably applied even when an oxide film forming step different from the above-described method is performed.

In the above-described embodiment, the case where nitrogen is doped into the SiO ₂ film using N ₂ O gas has been described, but the present invention is not limited to the above case. For example, the present invention can also be suitably applied to the case where other films such as a silicon oxide film such as a SiO film, a silicon nitride film, a polysilicon film, and a metal film are doped with nitrogen. Further, the present invention is not limited to the case of doping with gaseous nitrogen, but can be suitably applied to the case of doping with other elements. That is, the present invention can be suitably applied to any substrate processing method using a gas whose characteristics such as the concentration of active species change by changing the residence time (heating time).

  Further, the present invention can be suitably applied to both a vertical substrate processing apparatus and a single substrate processing apparatus. Further, the present invention can be applied to all substrate processing apparatuses such as a CVD apparatus, an oxide film forming apparatus, a diffusion apparatus, an annealing apparatus, and a batch type plasma processing apparatus.

  In the above-described embodiment, the case where the processing is performed on the wafer 25 as a substrate has been described. However, the present invention is applied to other substrates such as a photomask, a printed wiring board, a liquid crystal panel, a compact disk, a magnetic disk, and a glass substrate. Even if it is a case where a process is performed with respect to, it can apply suitably.

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

According to a first aspect of the invention,
Carrying a substrate into a processing chamber provided in the reaction vessel;
Supplying and retaining gas in a gas retention chamber provided in the reaction vessel, supplying the retained gas into the processing chamber, and processing the substrate;
And a step of unloading the processed substrate from the processing chamber,
In the step of processing the substrate,
A plurality of baffle plates provided so that a plurality of holes are dispersed in a plane are stacked in a horizontal posture on the gas flow path in the gas retention chamber at a predetermined interval,
There is provided a substrate processing method in which the respective baffle plates are arranged so that the holes of the adjacent baffle plates do not overlap each other and the gas is retained at a temperature at which the gas is decomposed.

According to a second aspect of the invention,
An oxide film is formed on the surface of the substrate,
The step of processing the substrate comprises:
N ₂ O gas is supplied and retained in the gas retention chamber, the retained N ₂ O gas is decomposed in the gas retention chamber to generate NO gas, and the retained N ₂ O gas and the generation A substrate processing method according to a first aspect is provided, which includes an N ₂ O annealing step of supplying nitrogen gas (N) added into the processing chamber and adding nitrogen (N) into the oxide film.

According to a third aspect of the invention,
The step of processing the substrate comprises:
An oxide film forming step of supplying an oxygen-containing gas into the processing chamber to form an oxide film on the surface of the substrate;
N ₂ O gas is supplied and retained in the gas retention chamber, the retained N ₂ O gas is decomposed in the gas retention chamber to generate NO gas, and the retained N ₂ O gas and the generation An N ₂ O annealing step of supplying nitrogen gas into the processing chamber and adding nitrogen into the oxide film,
In both the oxide film forming step and the N ₂ O annealing step, the substrate processing method according to the first aspect is provided in which the surface of the substrate is heated to the same temperature within a range of 900 ° C. to 1000 ° C.

According to a fourth aspect of the invention,
A SiO ₂ film is formed on the surface of the substrate,
The step of processing the substrate comprises:
N ₂ O gas is supplied and retained in the gas retention chamber, the retained N ₂ O gas is decomposed in the gas retention chamber to generate NO gas, and the retained N ₂ O gas and the generation The substrate processing method according to the first aspect is provided, which includes an N ₂ O annealing step of supplying the processed NO gas into the processing chamber and adding nitrogen into the SiO ₂ film to form a SiON film.

According to a fifth aspect of the present invention,
A SiO ₂ film is formed on the surface of the substrate,
The step of processing the substrate comprises:
N ₂ O gas is supplied and retained in the gas retention chamber, and the retained N ₂ O gas is heated at a temperature of 1000 ° C. for 10 seconds or more to be decomposed in the gas retention chamber to generate NO gas. A first N ₂ O annealing step of supplying the retained N ₂ O gas and the generated NO gas into the processing chamber and adding nitrogen into the SiO ₂ film to form a SiON film. A substrate processing method according to an aspect is provided.

According to a sixth aspect of the present invention,
In the step of processing the substrate,
A substrate processing method according to a first aspect is provided in which a gas is supplied from a ceiling portion of the reaction vessel into the gas retention chamber.

According to a seventh aspect of the present invention,
A processing chamber provided in the reaction vessel for processing the substrate;
A gas supply system for supplying gas into the reaction vessel;
A gas retention chamber that is provided in the reaction vessel, retains the gas supplied from the gas supply system, and supplies the retained gas into the processing chamber;
A gas exhaust system for exhausting the atmosphere in the processing chamber,
A plurality of baffle plates provided so that a plurality of holes are dispersed in a plane on the gas flow path in the gas retention chamber are stacked in a horizontal posture at a predetermined interval,
A substrate processing apparatus is provided in which each of the baffle plates is arranged so that the holes of the adjacent baffle plates do not overlap each other.

According to an eighth aspect of the present invention,
The substrate processing apparatus according to a seventh aspect, in which the gas supply system is wound around the outer periphery of the reaction vessel so as to preheat the gas supplied into the gas retention chamber.

According to a ninth aspect of the present invention,
The substrate processing apparatus according to the seventh aspect is provided in which the gas retention chamber is filled with a flow resistor.

According to a tenth aspect of the present invention,
A substrate processing apparatus according to a ninth aspect is provided, wherein the flow resistor is made of a ceramic material such as an oxide, carbide, nitride, or boride and is configured as a porous body.

According to an eleventh aspect of the present invention,
Carrying a substrate into a processing chamber provided in the reaction vessel;
Supplying and retaining gas in a gas retention chamber provided in the reaction vessel, supplying the retained gas into the processing chamber, and processing the substrate;
And a step of unloading the processed substrate from the processing chamber,
In the step of processing the substrate,
A plurality of baffle plates provided so that a plurality of holes are dispersed in a plane are stacked in a horizontal posture at a predetermined interval on the gas flow path in the gas retention chamber,
There is provided a substrate processing method in which the respective baffle plates are arranged so that the holes of the adjacent baffle plates do not overlap each other.

It is a longitudinal cross-sectional view of the processing furnace with which the substrate processing apparatus concerning one Embodiment of this invention is provided. It is a longitudinal cross-sectional enlarged view of the gas supply part with which the substrate processing apparatus concerning one Embodiment of this invention is provided. It is a horizontal sectional view of a processing furnace with which a substrate processing apparatus concerning one embodiment of the present invention is provided. It is a perspective sectional view of a gas supply part with which a substrate processing apparatus concerning one embodiment of the present invention is provided. It is a graph which shows the simulation result which verified the relationship between the residence time of gas, and the molar fraction of NO gas. It is a longitudinal cross-sectional view of the processing furnace with which the substrate processing apparatus concerning other embodiment of this invention is provided. It is a longitudinal cross-sectional view of the processing furnace with which the substrate processing apparatus concerning other embodiment of this invention is provided. It is a longitudinal cross-sectional enlarged view of the gas supply part with which the substrate processing apparatus concerning other embodiment of this invention is provided. It is a longitudinal cross-sectional view of the processing furnace with which the conventional substrate processing apparatus is provided. It is a horizontal sectional view of the processing furnace with which the conventional substrate processing apparatus is provided. It is a longitudinal cross-sectional enlarged view of the gas supply part with which the conventional substrate processing apparatus is provided. It is a schematic block diagram of the substrate processing apparatus concerning one Embodiment of this invention. Is a graph showing the measurement results of the relationship between the doping depth and segregation of nitrogen in the SiO ₂ film. It is a schematic diagram illustrating a decomposition reaction step of the N 2 _O gas.

Explanation of symbols

5 Processing furnace 6 Reaction vessel 7 Gas supply unit 10 Gas introduction pipe (gas supply system)
10a N ₂ O gas supply pipe 11 treatment chamber 12 exhaust pipe (gas exhaust system)
14 Vacuum pump 17 First baffle plate 17a Vent hole 18 Second baffle plate 18a Vent hole 20 Shower plate 20a Vent hole 21 Gas retention chamber 25 Wafer (substrate)
101 substrate processing apparatus 280 controller

Claims (3)

Carrying a substrate into a processing chamber provided in the reaction vessel;
Supplying and retaining gas in a gas retention chamber provided in the reaction vessel, supplying the retained gas into the processing chamber, and processing the substrate;
And a step of unloading the processed substrate from the processing chamber,
In the step of processing the substrate,
A plurality of baffle plates provided so that a plurality of holes are dispersed in a plane are stacked in a horizontal posture on the gas flow path in the gas retention chamber at a predetermined interval,
A substrate processing method, wherein each of the baffle plates is disposed so that the holes of the adjacent baffle plates do not overlap each other, and the gas is retained at a temperature at which the gas is decomposed. An oxide film is formed on the surface of the substrate,
The step of processing the substrate comprises:
N ₂ O gas is supplied and retained in the gas retention chamber, the retained N ₂ O gas is decomposed in the gas retention chamber to generate NO gas, and the retained N ₂ O gas and the generation _2. The substrate processing method according to claim 1, further comprising: an N ₂ O annealing step of supplying the processed NO gas into the processing chamber and adding nitrogen (N) into the oxide film. The step of processing the substrate comprises:
An oxide film forming step of supplying an oxygen-containing gas into the processing chamber to form an oxide film on the surface of the substrate;
N ₂ O gas is supplied and retained in the gas retention chamber, the retained N ₂ O gas is decomposed in the gas retention chamber to generate NO gas, and the retained N ₂ O gas and the generation An N ₂ O annealing step of supplying nitrogen gas into the processing chamber and adding nitrogen into the oxide film,
_2. The substrate processing method according to claim 1, wherein in both the oxide film forming step and the N ₂ O annealing step, the surface of the substrate is heated to the same temperature within a range of 900 ° C. to 1000 ° C. 3.

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