WO2018088003A1 - Manufacturing method for semiconductor device, substrate processing device, and program - Google Patents

Abstract

The present invention includes a step for forming an oxide film on a substrate by executing, a prescribed number of times, a cycle in which a step for suppling raw material gas to the substrate via a first nozzle and a step for supplying a first oxygen-containing gas to the substrate via a second nozzle differing from the first nozzle are carried out non-simultaneously. The step for supplying raw material gas includes a period during which a second oxygen-containing gas is supplied to the substrate via a third nozzle differing from the first nozzle and the second nozzle.

Description

Semiconductor device manufacturing method, substrate processing apparatus, and program

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

As a process of manufacturing a semiconductor device (device), by performing a predetermined number of cycles in which a process of supplying a source gas to a substrate and a process of supplying an oxygen-containing gas to a substrate are performed simultaneously, A process of forming an oxide film on the substrate may be performed (see, for example, Patent Document 1).

JP 2010-153776 A

An object of the present invention is to provide a technique capable of improving the smoothness and film thickness uniformity of an oxide film formed on a substrate.

According to one aspect of the invention,
Supplying a source gas from the first nozzle to the substrate;
Supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate;
Having a process of forming an oxide film on the substrate by performing a non-simultaneous cycle a predetermined number of times,
The step of supplying the source gas includes a technique including a period in which a second oxygen-containing gas is supplied to the substrate from a third nozzle different from the first nozzle and the second nozzle.

According to the present invention, it is possible to improve the smoothness and film thickness uniformity of an oxide film formed on a substrate.

It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus used suitably by one Embodiment of this invention, and is a figure which shows a processing furnace part with a longitudinal cross-sectional view. FIG. 2 is a schematic configuration diagram of a vertical processing furnace of a substrate processing apparatus preferably used in an embodiment of the present invention, and is a diagram showing a processing furnace part in a cross-sectional view taken along line AA of FIG. It is a schematic block diagram of the controller of the substrate processing apparatus used suitably by one Embodiment of this invention, and is a figure which shows the control system of a controller with a block diagram. (A) is a figure which shows the film-forming sequence of one Embodiment of this invention, (b) is a figure which shows the modification. (A) is a figure which shows the mode of the wafer surface at the time of raw material gas supply at the time of performing film-forming processing at comparatively low temperature, (b) at the time of raw material gas supply at the time of performing film-forming processing at comparatively high temperature, It is a figure which shows a mode that Si adsorb | sucked to the wafer surface moves (migration), (c) supplies oxygen gas with source gas at the time of source gas supply at the time of performing the film-forming process at comparatively high temperature It is a figure which shows a mode that the migration of Si adsorbed on the wafer surface is suppressed. (A) is a figure which shows the evaluation result regarding the film thickness uniformity in the wafer surface of the SiO film in an Example, and between wafers, (b) is the film thickness uniformity in the wafer surface of the SiO film in a comparative example, and between wafers. It is a figure which shows the evaluation result regarding sex. It is a schematic block diagram of the processing furnace of the substrate processing apparatus used suitably by other embodiment of this invention, and is a figure which shows a processing furnace part with a cross-sectional view, and extracts a reaction tube, a nozzle, an exhaust pipe, a wafer, etc. FIG.

<One Embodiment of the Present Invention>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

(1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, the processing furnace 202 has a heater 207 as a heating mechanism (temperature adjustment unit). The heater 207 has a cylindrical shape and is vertically installed by being supported by a holding plate. The heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas with heat.

A reaction tube 203 is disposed inside the heater 207 concentrically with the heater 207. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end opened. A manifold 209 is disposed below the reaction tube 203 concentrically with the reaction tube 203. The manifold 209 is made of a metal material such as stainless steel (SUS), for example, and has a cylindrical shape with an upper end and a lower end opened. The upper end portion of the manifold 209 is engaged with the lower end portion of the reaction tube 203 and is configured to support the reaction tube 203. An O-ring 220a as a seal member is provided between the manifold 209 and the reaction tube 203. The reaction tube 203 is installed vertically like the heater 207. The reaction vessel 203 and the manifold 209 mainly constitute a processing vessel (reaction vessel). A processing chamber 201 is formed in the hollow cylindrical portion of the processing container. The processing chamber 201 is configured to accommodate a wafer 200 as a substrate.

In the processing chamber 201, a nozzle 249a as a first nozzle, a nozzle 249b as a second nozzle, and a nozzle 249c as a third nozzle are provided so as to penetrate the side wall of the manifold 209. Gas supply pipes 232a to 232c are connected to the nozzles 249a to 249c, respectively.

The gas supply pipes 232a to 232c are provided with mass flow controllers (MFC) 241a to 241c, which are flow rate controllers (flow rate control units), and valves 243a to 243c, which are on-off valves, in order from the upstream side of the gas flow. . Gas supply pipes 232d to 232f are connected to the gas supply pipes 232a to 232c on the downstream side of the valves 243a to 243c, respectively. The gas supply pipes 232d to 232f are respectively provided with MFCs 241d to 241f and valves 243d to 243f in order from the upstream side of the gas flow.

As shown in FIG. 2, the nozzles 249a to 249c are arranged in an annular space in a plan view between the inner wall of the reaction tube 203 and the wafer 200, along the upper part from the lower part of the inner wall of the reaction tube 203. Each is provided so as to rise upward in the arrangement direction. That is, the nozzles 249a to 249c are provided along the wafer arrangement area in the area horizontally surrounding the wafer arrangement area on the side of the wafer arrangement area where the wafers 200 are arranged. As shown in FIG. 2, the nozzles 249a to 249c are different nozzles.

As shown in FIG. 2, the nozzles 249a and 249b are arranged so as to face (face to) an exhaust port 231a to be described later with the wafer 200 carried into the processing chamber 201 interposed therebetween in a plan view. The nozzle 249b is disposed in the vicinity of the nozzle 249a. The nozzle 249c is disposed at a position farther from the nozzle 249a than the nozzle 249b. By arranging the nozzles 249a to 249c in this way, the distance A between the nozzles 249a and 249b and the distance B between the nozzles 249a and 249c have different sizes (distances). A ≠ distance B). Specifically, the distance B between the nozzle 249a and the nozzle 249c is larger than the distance A between the nozzle 249a and the nozzle 249b (distance B> distance A). Further, the fan-shaped center angle θ ₂ formed by the nozzle 249 a, the nozzle 249 c, and the center 200 a of the wafer 200 is larger than the fan-shaped center angle θ ₁ formed by the nozzle 249 a, the nozzle 249 b, and the center 200 a of the wafer 200. It is larger (center angle θ ₂ > center angle θ ₁ ).

The above-mentioned distance B is, for example, 30 cm or more and 80 cm or less, and the above-mentioned distance A is, for example, 1 cm or more and 5 cm or less. Further, the above-described central angle θ ₂ has a size within a range of, for example, 90 ° to less than 180 °, and the above-described central angle θ ₂ has a size within a range of, for example, 3 ° to less than 60 °.

Gas supply holes 250a to 250c for supplying gas are provided on the side surfaces of the nozzles 249a to 249c, respectively. The gas supply holes 250 a to 250 c are opened so as to face the central portion of the reaction tube 203, and gas can be supplied toward the central portion of the wafer 200. As shown in FIG. 2, the gas supply holes 250a and 250b are provided so as to face (face to) the exhaust port 231a with the wafer 200 interposed therebetween in plan view. A plurality of gas supply holes 250 a to 250 c are provided from the lower part to the upper part of the reaction tube 203. The distance A may be considered as a distance between the gas supply hole 250a and the gas supply hole 250b, and the distance B may be considered as a distance between the gas supply hole 250a and the gas supply hole 250c.

From the gas supply pipe 232a, as a raw material (raw material gas), for example, a halosilane raw material gas containing silicon (Si) as a predetermined element (main element) and a halogen element is passed through the MFC 241a, the valve 243a, and the nozzle 249a. Supplied into 201. The raw material gas is a gaseous raw material, for example, a gas obtained by vaporizing a raw material that is in a liquid state under normal temperature and normal pressure, or a raw material that is in a gaseous state under normal temperature and normal pressure. The halogen element includes chlorine (Cl), fluorine (F), bromine (Br), iodine (I) and the like. As the halosilane source gas, for example, a source gas containing Si and Cl, that is, a chlorosilane source gas can be used. The chlorosilane source gas acts as a Si source. As the chlorosilane source gas, for example, hexachlorodisilane (Si ₂ Cl ₆ , abbreviation: HCDS) gas can be used.

From the gas supply pipes 232b and 232c, for example, oxygen (O) -containing gas is supplied into the processing chamber 201 through the MFCs 241b and 241c, valves 243b and 243c, and nozzles 249b and 249c as reactants (reaction gas). Is done. In the present specification, the O-containing gas supplied from the nozzle 249b in Step 2 of the film formation process described later is also referred to as a first O-containing gas, and the O-containing gas supplied from the nozzle 249c in Step 1 of the film formation process. The gas is also referred to as a second O-containing gas. The first O-containing gas acts as an oxidizing source (oxidant, oxidizing gas), that is, an O source. The second O-containing gas acts as a migration suppression gas that suppresses migration of Si adsorbed on the wafer 200. For example, oxygen (O ₂ ) gas can be used as the first and second O-containing gases.

From the gas supply pipe 232a, for example, a hydrogen (H) -containing gas is supplied into the processing chamber 201 through the MFC 241a, the valve 243a, and the nozzle 249a as a reactant (reaction gas). Although the H-containing gas alone cannot be oxidized, it reacts with the O-containing gas under specific conditions in the film-forming process described below, thereby oxidizing oxidizing species such as atomic oxygen (O). It acts to improve the efficiency of the oxidation treatment. As the H-containing gas, for example, hydrogen (H ₂ ) gas can be used.

From the gas supply pipes 232d to 232f, for example, nitrogen (N ₂ ) gas as an inert gas passes through the MFCs 241d to 241f, valves 243d to 243f, gas supply pipes 232a to 232c, and nozzles 249a to 249c, respectively. Supplied into 201. N ₂ gas acts as a purge gas and a carrier gas.

Mainly, the gas supply pipe 232a, the MFC 241a, and the valve 243a constitute a first supply system that supplies the source gas. The gas supply pipe 232b, the MFC 241b, and the valve 243b mainly constitute a second supply system that supplies the first O-containing gas. When the H-containing gas is supplied from the gas supply pipe 232a simultaneously with the supply of the O-containing gas from the second supply system, the gas supply pipe 232a, the MFC 241a, and the valve 243a may be included in the second supply system. A third supply system that supplies the second O-containing gas is mainly configured by the gas supply pipe 232c, the MFC 241c, and the valve 243c. An inert gas supply system is mainly configured by the gas supply pipes 232d to 232f, the MFCs 241d to 241f, and the valves 243d to 243f.

Any or all of the various supply systems described above may be configured as an integrated supply system 248 in which valves 243a to 243f, MFCs 241a to 241f, and the like are integrated. The integrated supply system 248 is connected to each of the gas supply pipes 232a to 232f, and supplies various gases into the gas supply pipes 232a to 232f, that is, opens and closes the valves 243a to 243f and MFCs 241a to 241f. The flow rate adjusting operation and the like are configured to be controlled by a controller 121 described later. The integrated supply system 248 is configured as an integrated or divided type integrated unit, and can be attached to and detached from the gas supply pipes 232a to 232f in units of integrated units. Maintenance, replacement, expansion, etc. can be performed in units of integrated units.

The reaction tube 203 is provided with an exhaust port 231a for exhausting the atmosphere in the processing chamber 201. An exhaust pipe 231 is connected to the exhaust port 231a. The exhaust pipe 231 is connected to a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). A vacuum pump 246 as a vacuum exhaust device is connected. The APC valve 244 can perform vacuum evacuation and vacuum evacuation stop in the processing chamber 201 by opening and closing the valve with the vacuum pump 246 activated, and further, with the vacuum pump 246 activated, The pressure in the processing chamber 201 can be adjusted by adjusting the valve opening based on the pressure information detected by the pressure sensor 245. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

Below the manifold 209, a seal cap 219 is provided as a furnace opening lid capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of a metal material such as SUS and is formed in a disk shape. On the upper surface of the seal cap 219, an O-ring 220b is provided as a seal member that comes into contact with the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 for rotating a boat 217 described later is installed. A rotation shaft 255 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be raised and lowered in the vertical direction by a boat elevator 115 as an elevating mechanism installed outside the reaction tube 203. The boat elevator 115 is configured as a transfer device (transfer mechanism) that carries the wafer 200 in and out of the processing chamber 201 by moving the seal cap 219 up and down. Below the manifold 209, a shutter 219s is provided as a furnace opening lid capable of airtightly closing the lower end opening of the manifold 209 with the seal cap 219 lowered and the boat 217 carried out of the processing chamber 201. Yes. The shutter 219s is made of a metal material such as SUS, and is formed in a disk shape. On the upper surface of the shutter 219s, an O-ring 220c as a seal member that comes into contact with the lower end of the manifold 209 is provided. The opening / closing operation (elevating operation, rotating operation, etc.) of the shutter 219s is controlled by the shutter opening / closing mechanism 115s.

The boat 217 as a substrate support is configured to support a plurality of, for example, 25 to 200, wafers 200 in a multi-stage manner by aligning them vertically in a horizontal posture and with their centers aligned. It is configured to arrange at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. Under the boat 217, heat insulating plates 218 made of a heat resistant material such as quartz or SiC are supported in multiple stages.

In the reaction tube 203, a temperature sensor 263 is installed as a temperature detector. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature in the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer having a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. Has been. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to exchange data with the CPU 121a via the internal bus 121e. For example, an input / output device 122 configured as a touch panel or the like is connected to the controller 121.

The storage device 121c includes, for example, a flash memory, a HDD (Hard Disk Drive), and the like. In the storage device 121c, a control program that controls the operation of the substrate processing apparatus, a process recipe that describes the procedure and conditions of the substrate processing described later, and the like are stored in a readable manner. The process recipe is a combination of processes so that a predetermined result can be obtained by causing the controller 121 to execute each procedure in substrate processing to be described later, and functions as a program. Hereinafter, process recipes, control programs, and the like are collectively referred to simply as programs. The process recipe is also simply called a recipe. When the term “program” is used in this specification, it may include only a recipe, only a control program, or both. The RAM 121b is configured as a memory area (work area) in which programs, data, and the like read by the CPU 121a are temporarily stored.

The I / O port 121d includes the above-described MFCs 241a to 241f, valves 243a to 243f, pressure sensor 245, APC valve 244, vacuum pump 246, temperature sensor 263, heater 207, rotation mechanism 267, boat elevator 115, shutter opening / closing mechanism 115s, etc. It is connected to the.

The CPU 121a is configured to read out and execute a control program from the storage device 121c and to read a recipe from the storage device 121c in response to an operation command input from the input / output device 122 or the like. The CPU 121a adjusts the flow rate of various gases by the MFCs 241a to 241f, the opening / closing operation of the valves 243a to 243f, the opening / closing operation of the APC valve 244, and the pressure adjustment by the APC valve 244 based on the pressure sensor 245 so as to follow the contents of the read recipe. Operation, start and stop of the vacuum pump 246, temperature adjustment operation of the heater 207 based on the temperature sensor 263, rotation and rotation speed adjustment operation of the boat 217 by the rotation mechanism 267, raising / lowering operation of the boat 217 by the boat elevator 115, shutter opening / closing mechanism 115s Is configured to control the opening / closing operation and the like of the shutter 219s.

The controller 121 installs the above-mentioned program stored in an external storage device (for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, or a semiconductor memory such as a USB memory) 123 in a computer. Can be configured. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as a recording medium. When the term “recording medium” is used in this specification, it may include only the storage device 121c alone, may include only the external storage device 123 alone, or may include both of them. The program may be provided to the computer using a communication means such as the Internet or a dedicated line without using the external storage device 123.

(2) Film Forming Process Regarding a sequence example in which a silicon oxide film (SiO film) is formed on a wafer 200 as a substrate as one step of a semiconductor device manufacturing process using the substrate processing apparatus described above, FIG. Will be described. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

In the film forming sequence shown in FIG.
Supplying HCDS gas from the nozzle 249a to the wafer 200;
Step 2 of supplying O ₂ gas from the nozzle 249b to the wafer 200;
By performing a non-simultaneous cycle a predetermined number of times (one or more times), an SiO film is formed on the wafer 200 as a film containing Si and O.

Step 1 described above includes a period during which O ₂ gas is supplied from the nozzle 249 c to the wafer 200. That is, step 1 includes a period during which HCDS gas and O ₂ gas are supplied to the wafer 200 simultaneously. Further, step 2 described above includes a period during which O ₂ gas and H ₂ gas are simultaneously supplied to the wafer 200. The H ₂ gas is supplied from the nozzle 249a disposed in the vicinity of the nozzle 249b that supplies the O ₂ gas in Step 2.

In this specification, the film forming sequence shown in FIG. 4A may be shown as follows for convenience. The same notation is used in the following description of the modified examples.

(HCDS + O ₂ → O ₂ + H ₂ ) × n ⇒ SiO

When the term “wafer” is used in this specification, it may mean the wafer itself or a laminate of the wafer and a predetermined layer or film formed on the surface thereof. When the term “wafer surface” is used in this specification, it may mean the surface of the wafer itself, or may mean the surface of a predetermined layer or the like formed on the wafer. In this specification, the phrase “form a predetermined layer on the wafer” means that the predetermined layer is directly formed on the surface of the wafer itself, a layer formed on the wafer, etc. It may mean that a predetermined layer is formed on the substrate. In this specification, the term “substrate” is also synonymous with the term “wafer”.

(Wafer charge and boat load)
When a plurality of wafers 200 are loaded into the boat 217 (wafer charge), the shutter 219s is moved by the shutter opening / closing mechanism 115s, and the lower end opening of the manifold 209 is opened (shutter open). Thereafter, as shown in FIG. 1, the boat 217 that supports the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201 (boat loading). In this state, the seal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

(Pressure adjustment and temperature adjustment)
The inside of the processing chamber 201 is evacuated (reduced pressure) by the vacuum pump 246 so that the space in which the wafer 200 exists is at a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. Further, the wafer 200 in the processing chamber 201 is heated by the heater 207 so as to have a desired film formation temperature. At this time, the power supply to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Further, the rotation of the wafer 200 by the rotation mechanism 267 is started. The exhaust in the processing chamber 201 and the heating and rotation of the wafer 200 are all continuously performed at least until the processing on the wafer 200 is completed.

(Deposition step)
Thereafter, the following steps 1 and 2 are sequentially executed.

[Step 1]
In this step, HCDS gas and O ₂ gas are simultaneously supplied from different nozzles to the wafer 200 in the processing chamber 201.

Specifically, the valves 243a and 243c are opened, and HCDS gas and O ₂ gas are allowed to flow into the gas supply pipes 232a and 232c, respectively. The flow rates of the HCDS gas and the O ₂ gas are adjusted by the MFCs 241a and 241c, respectively, supplied into the processing chamber 201 through the nozzles 249a and 249c, mixed in the processing chamber 201, and exhausted from the exhaust port 231a. At this time, HCDS gas and O ₂ gas are supplied to the wafer 200 simultaneously (together). At the same time, the valves 243d and 243f are opened, and N ₂ gas flows into the gas supply pipes 232d and 232f, respectively. The flow rate of the N ₂ gas is adjusted by the MFCs 241d and 241f, and the N ₂ gas is supplied into the processing chamber 201 together with the HCDS gas and the O ₂ gas. Further, in order to prevent entry of HCDS gas or the like into the nozzle 249b, the valve 243e is opened, and N ₂ gas is caused to flow into the gas supply pipe 232e. The N ₂ gas is supplied into the processing chamber 201 through the gas supply pipe 232b and the nozzle 249b.

The supply flow rate F ₁ of the O ₂ gas supplied from the nozzle 249c is the same as the supply amount Q ₁ of the O ₂ gas (second O-containing gas) in step 1 per cycle. ₂ gas is set to (first O-containing gas) is smaller than the supply amount _{Q 2} of _(Q 1 _{<Q 2)} such trace amounts of flow. When the supply time of O ₂ gas in Step 1 is the same as the supply time of O ₂ gas in Step 2, F ₁ is more than the supply flow rate F ₂ of O ₂ gas supplied from the nozzle 249b in Step 2. By making it smaller, it is possible to satisfy Q ₁ <Q ₂ . In view of thickness uniformity and the like of the SiO film formed on the wafer 200, _{F 1} is smaller than _{F 2 (F} 1 _{<F 2)} of preferably, for example, _{F 2} 1/20 or 1 / The flow rate can be a very small flow rate of 2 or less, preferably 1/10 or more and 1/5 or less. Note that F ₂ is a flow rate that can sufficiently oxidize the first layer formed in Step 1 in Step 2.

If F ₁ is less than 1/20 of F _2, the effect of suppressing the migration of Si described later with O ₂ gas may not be obtained, and the surface roughness of the SiO film formed on the wafer 200 tends to deteriorate. By setting F ₁ to be 1/20 or more of F ₂ , a migration suppressing effect can be obtained, and the surface roughness of the SiO film can be improved. By setting F ₁ to be 1/10 or more of F ₂ , a migration suppression effect can be obtained with certainty, and the surface roughness of the SiO film can be reliably improved. Here, “surface roughness” means a difference in height of the film in the wafer plane and is synonymous with surface roughness. An improvement in surface roughness means that this height difference is reduced and the surface becomes smooth. The deterioration of the surface roughness means that the height difference becomes large and the surface becomes rough.

If F ₁ exceeds 1/2 of F ₂ , an excessive gas phase reaction may occur, and the film thickness uniformity of the SiO film formed on the wafer 200 may easily deteriorate. By setting F ₁ to be ½ or less of F ₂ , an appropriate gas phase reaction can be caused, and the film thickness uniformity of the SiO film can be improved. By setting F ₁ to be 1/5 or less of F ₂ , the gas phase reaction can be appropriately suppressed, and the film thickness uniformity of the SiO film can be reliably improved.

As processing conditions in this step,
Deposition pressure (pressure in the processing chamber 201): 0.1 to 20 Torr (13.3 to 2666 Pa), preferably 1 to 10 Torr (133 to 1333 Pa)
HCDS gas supply flow rate: 1 to 2000 sccm, preferably 10 to 1000 sccm
O ₂ gas supply flow rate F ₁ (nozzle 249c): 1 to 1000 sccm, preferably 1 to 500 sccm
N ₂ gas supply flow rate (each gas supply pipe): 100 to 10000 sccm
Deposition temperature (temperature of wafer 200): 450 to 1000 ° C., preferably 600 to 1000 ° C., more preferably 700 to 900 ° C.
Each gas supply time is 1 to 100 seconds, preferably 1 to 50 seconds.

When the film forming temperature is lower than 450 ° C., it is difficult to form the SiO film on the wafer 200, and a practical film forming speed may not be obtained. This can be eliminated by setting the film forming temperature to 450 ° C. or higher. By setting the film forming temperature to 600 ° C. or higher, it is possible to improve the etching resistance of the SiO film formed on the wafer 200 with respect to hydrogen fluoride (HF) and the like. By setting the film forming temperature to 700 ° C. or higher, the etching resistance of the SiO film can be further improved.

When the film formation temperature exceeds 1000 ° C., an excessive gas phase reaction may occur, which may deteriorate the film thickness uniformity of the SiO film formed on the wafer 200. In addition, a large amount of particles may be generated in the processing chamber 201, which may deteriorate the quality of the film forming process. By setting the film forming temperature to a temperature of 1000 ° C. or lower, an appropriate gas phase reaction can be generated, the film thickness uniformity of the SiO film can be improved, and the generation of particles in the processing chamber 201 can be suppressed. It becomes possible. By setting the film forming temperature to 900 ° C. or lower, the film thickness uniformity of the SiO film can be reliably improved, and the generation of particles in the processing chamber 201 can be reliably suppressed.

The above-described temperature zone includes a temperature zone in which HCDS is thermally decomposed (self-decomposed) when HCDS gas is present alone in the processing chamber 201. Further, this temperature zone includes a temperature zone in which migration of Si contained in the HCDS gas occurs remarkably on the surface of the wafer 200 when the HCDS gas is supplied alone to the wafer 200.

By simultaneously supplying HCDS gas and O ₂ gas to the wafer 200 under the above-described conditions, the first layer (initial layer) on the outermost surface of the wafer 200 is, for example, less than one atomic layer (one molecular layer). Thus, a Si-containing layer containing Cl having a thickness of about several atomic layers (several molecular layers) is formed. In the Si-containing layer containing Cl, HCDS is physically adsorbed on the outermost surface of the wafer 200, a substance in which HCDS is partially decomposed (hereinafter, Si _x Cl _y ) is chemisorbed, or HCDS is thermally decomposed. It is formed by doing. The Si-containing layer containing Cl may be an HCDS or Si _x Cl _y adsorption layer (physical adsorption layer or chemical adsorption layer), or may be a Si layer containing Cl. The formation of the Si layer containing Cl can increase the thickness of the layer formed per cycle, rather than the formation of the adsorption layer of HCDS or Si _x Cl _y . In this specification, a Si-containing layer containing Cl is also simply referred to as a Si-containing layer.

When the thickness of the first layer exceeds several atomic layers, the modification effect in Step 2 described later does not reach the entire first layer. The minimum thickness of the first layer is less than one atomic layer. Therefore, it is preferable that the thickness of the first layer be less than one atomic layer to several atomic layers. By setting the thickness of the first layer to 1 atomic layer or less, the action of the reforming reaction in Step 2 described later can be relatively enhanced, and the time required for the reforming reaction in Step 2 can be shortened. Can do. The time required for forming the first layer in step 1 can also be shortened. As a result, the processing time per cycle can be shortened, and the total processing time can be shortened. That is, the film forming rate can be increased. Moreover, the controllability of the film thickness uniformity can be improved by setting the thickness of the first layer to 1 atomic layer or less.

In the process of forming the first layer, the main element adsorbed on the wafer 200, that is, Si contained in the first layer may move (migrate) on the surface of the wafer 200. In particular, as the deposition temperature is set higher, Si migration becomes more active, and the surface roughness of the SiO film formed on the wafer 200 tends to deteriorate. FIG. 5A is a diagram showing a state of the surface of the wafer 200 when the HCDS gas is supplied when film formation is performed under a relatively low temperature of less than 700 ° C. In such a temperature range, the migration of Si adsorbed on the wafer 200 is relatively gentle and does not significantly affect the surface roughness of the SiO film. FIG. 5B is a diagram showing a state of the surface of the wafer 200 when the HCDS gas is supplied when film formation is performed under a relatively high temperature condition of 700 ° C. or higher. In such a temperature range, the migration of Si adsorbed on the wafer 200 becomes remarkable, and the uneven structure may be formed on the surface of the first layer due to the aggregation of Si or the like. As a result, the interface roughness between the base and the SiO film or the surface roughness of the SiO film may be deteriorated.

In order to solve this problem, in this embodiment, HCDS gas and O ₂ gas are simultaneously supplied to the wafer 200 in step 1. By supplying the O ₂ gas together with the HCDS gas, at least a part of the Si is oxidized and converted into an oxide (SiO _x ) simultaneously with or before the adsorption of the Si onto the wafer 200. It becomes possible. Si adsorbed on the wafer 200 becomes difficult to migrate due to oxidation. That is, migration of Si atoms adsorbed on the wafer 200 is hindered by O atoms bonded to Si atoms. As a result, even when the temperature of the wafer 200 is set to the above-described temperature range, it is possible to avoid deterioration of the interface roughness between the base and the SiO film and the surface roughness of the SiO film. FIG. 5C is a diagram showing a state in which Si migration is suppressed by supplying O ₂ gas together with HCDS gas. FIG. 5C shows, on an atomic level, a state in which migration of Si atoms is blocked by O atoms adjacent to Si atoms adsorbed on wafer 200 and aggregation of Si is prevented. O ₂ gas supplied together with the HCDS gas can also be referred to as a migration suppressing gas because of its action. The inventors have supplied the HCDS gas and the O ₂ gas simultaneously to the wafer 200 in step 1 even when the temperature of the wafer 200 is set to a temperature within the range of 700 to 1000 ° C., for example. It has been confirmed that deterioration of the surface roughness of the SiO film can be avoided. Note that the first layer formed on the wafer 200 is a Si-containing layer that further includes O as well as Cl. However, in this specification, the Si-containing layer containing Cl and O is also referred to as a Si-containing layer containing Cl or simply as a Si-containing layer for convenience.

However, when supplying the O ₂ gas together with the HCDS gas, depending on the arrangement of the nozzles used to supply the O ₂ gas, the film thickness uniformity of the SiO film formed on the wafer 200 may be reduced. The inventors have made it clear through intensive studies. For example, when the O ₂ gas is supplied from the nozzle 249b disposed in the vicinity of the nozzle 249a used for supplying the HCDS gas in Step 1, the in-wafer surface thickness distribution (hereinafter referred to as the SiO film) of the SiO film formed on the wafer 200 is determined. The film thickness uniformity in the wafer 200 plane (simply referred to as in-plane film thickness distribution) is the thinnest distribution at the center of the wafer 200 and gradually increases toward the peripheral edge (central concave distribution). WiW) may decrease. Further, if O ₂ gas is supplied from the nozzle 249b in Step 1, the film thickness uniformity (WtW) of the SiO film between the wafers 200 may be lowered.

In order to solve these problems, in the present embodiment, when the HCDS gas and the O ₂ gas are supplied simultaneously, the O ₂ gas is supplied from a nozzle 249c different from the nozzles 249a and 249b. This makes it possible to adjust the supply point of the O ₂ gas supplied simultaneously with the HCDS gas to be a point other than the nozzles 249a and 249b. That is, it is possible to freely adjust the supply point of the trace O ₂ gas. As a result, compared to the case where the O ₂ gas is supplied from the nozzle 249b in step 1, it is possible to improve the WiW and WtW of the SiO film formed on the wafer 200, respectively.

This is because the distance A between the nozzles 249a and 249b and the distance B between the nozzles 249a and 249c have different sizes, and specifically, the distance B> the distance A. Those that, when the _{O 2} gas is supplied from the nozzle 249c at step 1, as compared with the case where _{O 2} gas supplied from the nozzle 249b disposed in the vicinity of the nozzles 249a, near the nozzle 249a, i.e., the peripheral portion of the wafer 200 Mixing (reaction) of HCDS gas and O ₂ gas in the vicinity can be appropriately suppressed. Thereby, it is possible to appropriately suppress the consumption of the HCDS gas supplied from the nozzle 249a before reaching the center of the wafer 200. Then, the supply amount of the HCDS gas to the wafer 200 can be made more uniform between the peripheral portion and the center portion of the wafer 200. As a result, the above-described formation reaction of the first layer can be performed at a uniform rate over the entire region from the peripheral part to the central part of the wafer 200 and over the entire region of the wafer arrangement region. As a result, the WiW and WtW of the SiO film formed on the wafer 200 can be improved.

In step 1, when the O ₂ gas is supplied from the nozzle 249c, the effect of improving the surface roughness of the above-described SiO film is improved over the surface of the wafer 200 as compared with the case where the O ₂ gas is supplied from the nozzle 249b. In addition, the wafers 200 can be obtained more evenly. This is because, in Step 1, the O ₂ gas supplied from the nozzle 249c is supplied to the wafer 200 after being more diffused than the O ₂ gas supplied from the nozzle 249b. Conceivable. In step 1, towards the _{O 2} gas supplied from the nozzle 249c it is easy to become a state of being diffused compared to _{O 2} gas supplied from the nozzle 249b, as described above, the direction of the nozzle 249c, nozzle 249b This is considered to be because the probability that the diffusion of O ₂ gas is hindered due to collision with HCDS gas, mixing, and the like is reduced.

After forming the first layer, the valves 243a and 243c are closed, and the supply of HCDS gas and O ₂ gas into the processing chamber 201 is stopped. Then, the inside of the processing chamber 201 is evacuated, and the gas remaining in the processing chamber 201 is removed from the processing chamber 201. At this time, the valves 243d to 243f are kept open and the supply of N ₂ gas into the processing chamber 201 is maintained. N ₂ gas acts as a purge gas.

As source gas, in addition to HCDS gas, chlorosilane source gas such as monochlorosilane (SiH ₃ Cl) gas, dichlorosilane (SiH ₂ Cl ₂ ) gas, trichlorosilane (SiHCl ₃ ) gas, tetrachlorosilane (SiCl ₄ ) gas, etc. Can be used. Further, as the source gas, tetrafluorosilane (SiF ₄ ) gas, tetrabromosilane (SiBr ₄ ) gas, tetraiodosilane (SiI ₄ ) gas, or the like can be used. That is, as source gas, halosilane source gas (halosilane compound) such as chlorosilane source gas (chlorosilane compound), fluorosilane source gas (fluorosilane compound), bromosilane source gas (bromosilane compound), iodosilane source gas (iodosilane compound), etc. Can be used.

As source gases, tetrakisdimethylaminosilane (Si [N (CH ₃ ) ₂ ] ₄ , abbreviation: 4DMAS) gas, trisdimethylaminosilane (Si [N (CH ₃ ) ₂ ] ₃ H, abbreviation: 3DMAS) gas, Bisdiethylaminosilane (Si [N (C ₂ H ₅ ) ₂ ] ₂ H ₂ , abbreviation BDEAS) gas, Bisteria butylaminosilane (SiH ₂ [NH (C ₄ H ₉ )] ₂ , abbreviation: BTBAS) gas, diisopropylaminosilane An aminosilane source gas (aminosilane compound) such as (SiH ₃ N [CH (CH ₃ ) ₂ ] ₂ , abbreviation: DIPAS) gas can also be used. The aminosilane source gas acts not only as an Si source but also as an N source and a C source.

Further, as a source gas, a silicon hydride gas (silicon hydride compound) such as a monosilane (SiH ₄ ) gas, a disilane (Si ₂ H ₆ ) gas, or a trisilane (Si ₃ H ₈ ) gas can be used.

Further, as source gases, hexamethyldisiloxane ([(CH ₃ ) ₃ Si] ₂ O) gas, tetramethyldisiloxane ([H (CH ₃ ) ₂ Si] ₂ O) gas, hexachlorodisiloxane ((Cl A siloxane source gas (siloxane compound) such as ₃ Si) ₂ O) gas or tetrachlorodisiloxane ((HCl ₂ Si) ₂ O) gas can be used. A siloxane compound is a compound having a skeleton of Si and O, and is a general term for those having a Si—O—Si bond (siloxane bond). The siloxane source gas acts not only as a Si source but also as an O source, or an O source and a C source.

Examples of the source gas include hexamethyldisilazane ([(CH ₃ ) ₃ Si] ₂ NH) gas, tetramethyldisilazane ([H (CH ₃ ) ₂ Si] ₂ NH) gas, hexachlorodisilazane ( A silazane raw material gas (silazane compound) such as (Cl ₃ Si) ₂ NH) gas or tetrachlorodisilazane ((HCl ₂ Si) ₂ NH) gas can be used. The silazane compound is a compound having Si and N as a skeleton, and is a general term for a compound having a silazane bond such as a Si—N—Si bond or a Si—N bond. The silazane source gas acts not only as an Si source but also as an N source, or an N source and a C source.

Thus, as the source gas, at least one selected from the group consisting of a silane compound (halosilane compound, aminosilane compound, silicon hydride compound), siloxane compound, and silazane compound can be used. Note that siloxane compounds and silazane compounds tend to have higher thermal decomposition temperatures (difficult to self-decompose) than silane compounds. When the film forming temperature is set to the high temperature side, by using a siloxane compound or a silazane compound as a raw material gas, excessive thermal decomposition can be suppressed and the controllability of the film forming process can be improved.

As the second O-containing gas, in addition to O ₂ gas, nitrous oxide (N ₂ O) gas, nitrogen monoxide (NO) gas, nitrogen dioxide (NO ₂ ) gas, ozone (O ₃ ) gas, or the like is used. be able to.

As the inert gas, various rare gases such as Ar gas, He gas, Ne gas, and Xe gas can be used in addition to N ₂ gas. This also applies to step 2 described later.

[Step 2]
After step 1 is completed, O ₂ gas and H ₂ gas are simultaneously supplied from different nozzles to the wafer 200 in the processing chamber 201.

Specifically, the opening / closing control of the valves 243b, 243a, 243d to 243f is performed in the same procedure as the opening / closing control of the valves 243c, 243a, 243d to 243f in Step 1. The flow rates of the O ₂ gas and H ₂ gas flowing through the gas supply pipes 232b and 232a are adjusted by the MFCs 241b and 241a, respectively, and are supplied into the processing chamber 201 through the nozzles 249b and 249a. The O ₂ gas and the H ₂ gas are mixed and reacted in the processing chamber 201 and then exhausted from the exhaust port 231a. At this time, O ₂ gas and H ₂ gas are simultaneously supplied to the wafer 200.

The supply flow rate of the O ₂ gas supplied from the nozzle 249b is larger than the supply flow rate of the O ₂ gas supplied in step 1, and the first layer formed in step 1 can be sufficiently oxidized. The flow rate.

As processing conditions in this step,
Deposition pressure (pressure in the processing chamber 201): 0.1 to 10 Torr (13.3 to 1333 Pa), preferably 0.1 to 3 Torr (13.3 to 399 Pa)
O ₂ gas supply flow rate F ₂ (nozzle 249b): 2000 to 10000 sccm
H ₂ gas supply flow rate (nozzle 249a): 2000 to 10000 sccm
Each gas supply time is 1 to 100 seconds, preferably 1 to 50 seconds. Other processing conditions are the same as the processing conditions in step 1.

By simultaneously supplying O ₂ gas and H ₂ gas into the processing chamber 201 under the above-described conditions, these gases are thermally activated (excited) by non-plasma in a heated reduced pressure atmosphere and reacted. and, thereby, water (H 2 _O) free of oxidizing species containing oxygen, such as atomic oxygen (O) is generated. Then, an oxidation treatment is performed on the first layer formed on the wafer 200 in Step 1 mainly by this oxidation species. Since the energy of this oxidized species is higher than the bond energy such as Si—Cl bond contained in the Si-containing layer, the energy of this oxidized species is given to the first layer, so that the Si contained in the first layer is given. The —Cl bond and the like are cut off. Cl or the like from which the bond with Si is cut is removed from the layer, and is discharged from the processing chamber 201 as a gaseous substance containing Cl such as Cl ₂ or HCl. Further, the remaining Si bonds due to the disconnection with Cl or the like are combined with O contained in the oxidized species to form Si—O bonds. In this way, the first layer is changed (modified) into the second layer, that is, the SiO layer having a low content of impurities such as Cl. According to this oxidation treatment, the oxidizing power can be greatly improved as compared with the case of supplying O ₂ gas alone or the case of supplying water vapor (H ₂ O gas). That is, by adding H ₂ gas to O ₂ gas in a reduced-pressure atmosphere, a significant effect of improving oxidizing power can be obtained compared to the case of supplying O ₂ gas alone or supplying H ₂ O gas. .

After changing the first layer to the second layer, the valves 243b and 243a are closed, and the supply of O ₂ gas and H ₂ gas into the processing chamber 201 is stopped. Then, the gas and the like remaining in the processing chamber 201 are removed from the processing chamber 201 by the same processing procedure and processing conditions as in step 1.

Examples of the first O-containing gas include O ₂ gas, N ₂ O gas, NO gas, NO ₂ gas, O ₃ gas, atomic oxygen (O), oxygen radical (O ^* ), and hydroxyl radical (OH ^* ) ^. ) Etc. can be used. That is, the first O-containing gas and the second O-containing gas may be gases having the same molecular structure (chemical structure) or gases having different molecular structures. When the first O-containing gas and the second O-containing gas are gas having the same molecular structure, the structure of the gas supply system can be simplified, and the manufacturing cost and maintenance cost of the substrate processing apparatus can be reduced. It is preferable at the point which can be made to do. When the first O-containing gas and the second O-containing gas are gases having different molecular structures, for example, a substance having a lower oxidizing power than the first O-containing gas is used as the second O-containing gas. Thus, it is preferable in that the excessive gas phase reaction in Step 1 can be surely suppressed and the controllability of the film thickness uniformity can be improved. For example, when O ₃ gas or O ₂ gas is used as the first O-containing gas, N ₂ O gas, NO gas, NO ₂ gas, or the like may be used as the second O-containing gas.

As the H-containing gas, deuterium (D ₂ ) gas or the like can be used in addition to H ₂ gas. When an aminosilane source gas or the like is used as the source gas, if O ₃ gas is used as the first O-containing gas, the film forming process can be performed at a sufficient (similar) film forming rate without using the H-containing gas. Can be advanced. That is, the H-containing gas can be not used.

[Perform a specified number of times]
An SiO film having a predetermined thickness is formed on the wafer 200 by performing a predetermined number of cycles (n times (n is an integer of 1 or more)) in which steps 1 and 2 are performed non-simultaneously, that is, alternately without being synchronized. can do. The above cycle is preferably repeated multiple times. That is, until the thickness of the second layer formed per cycle is smaller than the desired thickness and the thickness of the SiO layer formed by laminating the second layer becomes the desired thickness, The above cycle is preferably repeated a plurality of times.

(Purge and return to atmospheric pressure)
After the formation of the SiO film, N ₂ gas is supplied into the processing chamber 201 from each of the gas supply pipes 232d to 232f and exhausted from the exhaust port 231a. N ₂ gas acts as a purge gas. As a result, the inside of the processing chamber 201 is purged, and the gas, reaction by-products and the like remaining in the processing chamber 201 are removed from the processing chamber 201 (after purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

(Boat unload and wafer discharge)
The seal cap 219 is lowered by the boat elevator 115, the lower end of the manifold 209 is opened, and the processed wafer 200 is carried out from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the boat 217 ( Boat unloaded). After the boat unloading, the shutter 219s is moved, and the lower end opening of the manifold 209 is sealed by the shutter 219s via the O-ring 220c (shutter close). The processed wafer 200 is taken out of the reaction tube 203 and then taken out from the boat 217 (wafer discharge).

(3) Effects according to this embodiment According to this embodiment, one or a plurality of effects described below can be obtained.

(A) In step 1, by simultaneously supplying HCDS gas and O ₂ gas to the wafer 200, migration of Si contained in the first layer is suppressed, and the surface of the SiO film formed on the wafer 200 It becomes possible to improve roughness and the like. The effect of improving the surface roughness and the like is not limited to the case where the film forming temperature is set to a temperature in the range of 450 to 1000 ° C., but to a lower temperature (for example, a temperature in the range of 250 to 400 ° C.). Is obtained in the same way. However, Si migration tends to become more active as the deposition temperature increases. The technical significance of supplying the HCDS gas and the O ₂ gas at the same time in Step 1 is that the migration of Si contained in the HCDS gas occurs remarkably when the film forming temperature is supplied to the wafer 200 alone. The temperature becomes particularly large when the temperature is set in a range of 700 to 1000 ° C., for example.

(B) In step 1, O ₂ gas is supplied from a nozzle 249c different from the nozzles 249a and 249b, that is, O ₂ gas is supplied from a nozzle 249c disposed at a position farther from the nozzle 249a than the nozzle 249b. By supplying, the WiW and WtW of the SiO film formed on the wafer 200 can be improved. In addition, the above-described effect of improving the surface roughness of the SiO film can be obtained more uniformly over the wafer 200 surface and between the wafers 200.

(C) Step 2 the supply of _{O 2} gas in, can be performed with the nozzle 249b disposed in the vicinity of the nozzles 249a used for the supply of _{H 2} gas, oxidation by reaction with _{O 2} gas and _{H 2} gas It is possible to stably generate seeds. This makes it possible to improve the uniformity of the oxidation process performed in step 2 within the wafer 200 and between the wafers 200. Note that when the O ₂ gas is supplied from the nozzle 249 c away from the nozzle 249 a in step 2, the amount of oxidized species generated becomes unstable, and the oxidation process performed in step 2 is performed within the wafer 200 and between the wafers 200. The inventors have confirmed that the uniformity in the case may decrease.

(D) By forming (depositing) the SiO film on the wafer 200 instead of oxidizing the surface of the wafer 200, it is possible to suppress the diffusion of O to the base of the film forming process. As a result, it is possible to form a SiO film having desired insulation characteristics while satisfying the required specifications for manufacturing a semiconductor device. For example, when manufacturing a memory device having a 3D structure, it is necessary to form a SiO film having a desired insulation performance while keeping the diffusion depth of O into the base within an allowable range. On the other hand, in the method (thermal oxidation method) of oxidizing the surface of the wafer 200, it may be difficult to satisfy both of these requirements.

(E) By forming the SiO film by the alternating supply method in which steps 1 and 2 are performed non-simultaneously, compared to the case of forming the SiO film by the simultaneous supply method in which steps 1 and 2 are performed simultaneously, It becomes possible to improve film thickness controllability, in-plane film thickness uniformity, and the like. Such a film forming method is particularly effective when the ground of the film forming process has a 3D structure such as a line and space shape, a hole shape, a fin shape, or the like.

(F) When the film forming process is performed, the temperature of the wafer 200 is set to the above-described temperature range, so that a SiO film having high quality film characteristics can be formed. For example, by setting the film formation temperature to a temperature within the range of 450 to 1000 ° C., the film formation temperature is lower than the temperature of 450 ° C., for example, the temperature within the range of 250 to 400 ° C. It is also possible to improve etching resistance and insulation performance, extend the service life, and reduce the interface electron trap density that affects the response speed of the transistor.

(G) The above-described effects are obtained when a source gas other than HCDS gas is used, when a first O-containing gas other than O ₂ gas is used, when a H-containing gas other than H ₂ gas is used, or O ₂ The same can be obtained when the second O-containing gas other than the gas is used.

(4) Modified Example The film forming sequence in the present embodiment can be changed as in the following modified example.

(Modification 1)
The supply of O ₂ gas from the nozzle 249c may be performed not only during the HCDS gas supply period in step 1 but also during other periods. For example, as shown in FIG. 4B, the supply of O ₂ gas from the nozzle 249c is interrupted only during the HCDS gas supply period in Step 1, that is, not intermittently, but throughout the cycle. Alternatively, it may be performed continuously. Also in this modification, the same effect as the film forming sequence shown in FIG. Further, by constantly supplying a small amount of O ₂ gas into the processing chamber 201 as in this modified example, deactivation of unreacted HCDS (residual HCDS) adhering to the inner wall or the like of the processing chamber 201 is promoted, and the residual HCDS It is possible to prevent adverse effects on the film forming process due to the above. The supply flow rate of O ₂ gas from the nozzle 249c can be the same as the supply flow rate of O ₂ gas in Step 1 described above.

(Modification 2)
As in the film forming sequence shown below, an SiO film may be formed under an intermediate temperature condition using an aminosilane source gas and O ₃ gas. Alternatively, the SiO film may be formed under low temperature conditions using an aminosilane source gas and plasma-excited O ₂ gas (hereinafter also referred to as O ₂ ^* ). Further, the above-described silicon hydride gas may be used instead of the aminosilane source gas.

(BDEAS + O ₂ → O ₃ ) × n ⇒ SiO
(BDEAS + O ₂ → O ₂ ^* ) × n ⇒ SiO
(3DMAS + O ₂ → O ₃ ) × n ⇒ SiO
(BTBAS + O ₂ → O ₂ ^* ) × n ⇒ SiO
(SiH ₄ + O ₂ → O ₃ ) × n ⇒ SiO
(Si ₂ H ₆ + O ₂ → O ₂ ^* ) × n ⇒ SiO

(Modification 3)
As shown in the film forming sequence shown below, N and C containing gases such as N-containing gas such as ammonia (NH ₃ ) gas and triethylamine ((C ₂ H ₅ ) ₃ N, abbreviated as TEA) are used as the reaction gas. Further, a C-containing gas such as propylene (C ₃ H ₆ ) gas or a B-containing gas such as trichloroborane (BCl ₃ ) gas is used to form a silicon oxynitride film (SiON film), silicon oxycarbide on the wafer 200. A film (SiOC film), silicon oxycarbonitride film (SiOCN film), silicon borate carbonitride film (SiBOCN film), silicon borate nitride film (SiBON film), or the like may be formed.

(HCDS + O ₂ → NH ₃ → O ₂ ) × n ⇒ SiON
(HCDS + O ₂ → TEA → O ₂ ) × n ⇒ SiOC
(HCDS + O ₂ → C ₃ H ₆ → NH ₃ ) × n ⇒ SiOCN
(HCDS + O ₂ → C ₃ H ₆ → NH ₃ → O ₂ ) × n ⇒ SiOCN
(HCDS + O ₂ → BCl ₃ → C ₃ H ₆ → NH ₃ ) × n ⇒ SiBOCN
(HCDS + O ₂ → BCl ₃ → NH ₃ ) × n ⇒ SiBON

<Other embodiments>
The embodiment of the present invention has been specifically described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

The present invention relates to titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), molybdenum (Mo), tungsten (W), yttrium (Y), strontium (Sr), lanthanum The present invention is also applicable to the case where an oxide film (metal oxide film) containing a metal element such as (La), ruthenium (Ru), or aluminum (Al) as a main element is formed.

For example, titanium tetrachloride (TiCl ₄ ) gas, hafnium tetrachloride (HfCl ₄ ) gas, tantalum pentachloride (TaCl ₅ ) gas, trimethylaluminum (Al (CH ₃ ) ₃ , abbreviation: TMA) gas or the like is used as a raw material. , H ₂ O gas is used as the first O-containing gas, O ₂ gas is used as the second O-containing gas, and a TiO film, an HfO film, a TaO film, The present invention can be suitably applied also when forming a metal oxide film such as an AlO film.

(TiCl ₄ + O ₂ → H ₂ O) × n ⇒ TiO
(HfCl ₄ + O ₂ → H ₂ O) × n => HfO
(TaCl ₅ + O ₂ → H ₂ O) × n ⇒ TaO
(TMA + O ₂ → H ₂ O) × n ⇒ AlO

The processing procedure and processing conditions of the film forming process at this time can be the same as the processing procedures and processing conditions of the above-described embodiments and modifications. In these cases, the same effects as those of the above-described embodiments and modifications can be obtained. That is, the present invention is suitably applied when forming a metalloid oxide film containing a metalloid element such as Si as a main element or when forming a metal oxide film containing the various metal elements described above as a main element. be able to.

The recipe used for the substrate processing is preferably prepared individually according to the processing content and stored in the storage device 121c via the telecommunication line or the external storage device 123. And when starting a process, it is preferable that CPU121a selects a suitable recipe suitably from the some recipe stored in the memory | storage device 121c according to the content of the board | substrate process. Accordingly, it is possible to form films having various film types, composition ratios, film qualities, and film thicknesses with a single substrate processing apparatus with good reproducibility. Further, the burden on the operator can be reduced, and the processing can be started quickly while avoiding an operation error.

The above-described recipe is not limited to a case of newly creating, but may be prepared by changing an existing recipe that has already been installed in the substrate processing apparatus, for example. When changing the recipe, the changed recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the recipe is recorded. Further, an existing recipe that has already been installed in the substrate processing apparatus may be directly changed by operating the input / output device 122 provided in the existing substrate processing apparatus.

In the above-described embodiment, an example using a reaction tube configured as a single tube has been described. However, the present invention is not limited to the above-described embodiment. For example, as shown in a sectional view of the vertical processing furnace in FIG. 7, the reaction tube may be constituted by a double tube including an inner tube and an outer tube. In the processing furnace shown in FIG. 7, two buffer chambers and an exhaust port are provided on the side wall of the inner tube, and a first buffer chamber located far from the exhaust port (a buffer chamber at a position facing the exhaust port and the center of the wafer). ) In which the first and second nozzles are provided in the same arrangement as in the above-described embodiment, and the third nozzle is provided in the second buffer chamber on the side closer to the exhaust port in the same arrangement as in the above-described embodiment. . Then, by exhausting the annular space between the inner tube and the outer tube from the exhaust pipe connected to the outer tube, the processing chamber formed inside the inner tube is exhausted. The configuration other than the reaction tube described here is the same as the configuration of each part of the processing furnace shown in FIG. Even when the processing furnace configured as described above is used, the same effects as those of the above-described embodiment can be obtained.

In the above-described embodiment, an example in which a film is formed using a batch-type substrate processing apparatus that processes a plurality of substrates at one time has been described. The present invention is not limited to the above-described embodiment, and can be suitably applied to a case where a film is formed using, for example, a single-wafer type substrate processing apparatus that processes one or several substrates at a time. In the above-described embodiment, an example in which a film is formed using a substrate processing apparatus having a hot wall type processing furnace has been described. The present invention is not limited to the above-described embodiment, and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold wall type processing furnace.

Even when these substrate processing apparatuses are used, film formation can be performed with the same sequence and processing conditions as those of the above-described embodiments and modifications, and the same effects as these can be obtained.

Also, the above-described embodiments and modifications can be used in appropriate combination. The processing procedure and processing conditions at this time can be the same as the processing procedure and processing conditions of the above-described embodiment, for example.

Hereinafter, experimental results that support the effects obtained in the above-described embodiments and modifications will be described.

As an example, a substrate processing apparatus provided with a vertical processing furnace shown in FIG. 7 was used, and a SiO film was formed on the wafer by the film forming sequence shown in FIG. In Step 1, HCDS gas was supplied from the first nozzle, and O ₂ gas (migration suppression gas) was supplied from the third nozzle. In Step 2, O ₂ gas (oxidant) was supplied from the second nozzle, and H ₂ gas was supplied from the first nozzle. The processing conditions in each step are the conditions within the processing condition range described in the above embodiment.

As a comparative example, an SiO film was formed on a wafer by a film forming sequence shown in FIG. 4A using a substrate processing apparatus equipped with a vertical processing furnace shown in FIG. In Step 1, O ₂ gas (migration suppression gas) was supplied from the second nozzle. The nozzles for supplying other gases, processing procedures, and processing conditions were the same as those in the examples.

Then, in-wafer surface thickness uniformity [WiW] (±%) and inter-wafer thickness uniformity [WtW] (±%) of the SiO films in Examples and Comparative Examples were measured. FIG. 6A shows the evaluation result of the example, and FIG. 6B shows the evaluation result of the comparative example. In each of these drawings, TOP, CEN, and BTM indicate the position of the wafer in the wafer arrangement area, that is, the position of the wafer is the upper part, the center part, and the lower part in the wafer arrangement area, respectively. WiW indicates the degree of variation in the film thickness distribution in the wafer surface, and the smaller the value, the better the film thickness uniformity in the wafer surface. WtW indicates the degree of variation in film thickness distribution between wafers, and the smaller the value, the better the film thickness uniformity between wafers.

According to these figures, the SiO film in the example greatly improved the WiW at any position of TOP, CEN, and BTM, as compared with the SiO film in the comparative example, and further improved WtW. You can see that. That is, in step 1, the HCDS gas is supplied from the first nozzle, and the O ₂ gas, which is a migration suppression gas, is supplied from the third nozzle located at a position away from the first nozzle, thereby forming SiO formed on the wafer. It can be seen that the WiW and WtW of the film can be greatly improved.

200 wafer (substrate)
249a Nozzle (first nozzle)
249b Nozzle (second nozzle)
249c Nozzle (third nozzle)

Claims (16)

1. Supplying a source gas from the first nozzle to the substrate;
   Supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate;
   Having a process of forming an oxide film on the substrate by performing a non-simultaneous cycle a predetermined number of times,
   The step of supplying the source gas includes a method of supplying a second oxygen-containing gas to the substrate from a third nozzle different from the first nozzle and the second nozzle.
2. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a distance B between the first nozzle and the third nozzle is made larger than a distance A between the first nozzle and the second nozzle.
3. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the third nozzle is disposed at a position farther from the first nozzle than the second nozzle.
4. A sector-shaped central angle θ ₂ formed at the center of the first nozzle, the third nozzle, and the substrate is defined as a sector-shaped central angle formed at the center of the first nozzle, the second nozzle, and the substrate. The method for manufacturing a semiconductor device according to claim 1, wherein the manufacturing method is larger than θ ₁ .
5. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a supply amount of the second oxygen-containing gas per cycle is made smaller than a supply amount of the first oxygen-containing gas per cycle.
6. 6. The method of manufacturing a semiconductor device according to claim 5, wherein a supply flow rate of the second oxygen-containing gas per cycle is made smaller than a supply flow rate of the first oxygen-containing gas per cycle.
7. 6. The semiconductor according to claim 5, wherein a supply flow rate of the second oxygen-containing gas per cycle is 1/20 or more and 1/2 or less of a supply flow rate of the first oxygen-containing gas per cycle. Device manufacturing method.
8. The method for manufacturing a semiconductor device according to claim 1, wherein in the step of forming the oxide film on the substrate, the second oxygen-containing gas is continuously supplied from the third nozzle.
9. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a supply time of the second oxygen-containing gas per cycle is shorter than a supply time of the first oxygen-containing gas per cycle.
10. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the step of supplying the first oxygen-containing gas includes a period in which the first oxygen-containing gas and the hydrogen-containing gas are simultaneously supplied to the substrate.
11. 2. The method of manufacturing a semiconductor device according to claim 1, wherein in the step of forming the oxide film on the substrate, the temperature of the substrate is set to a temperature at which the source gas is thermally decomposed.
12. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the source gas includes at least one selected from the group consisting of a silane compound, a siloxane compound, and a silazane compound.
13. The first oxygen-containing gas includes at least one selected from the group consisting of oxygen gas, nitrous oxide gas, nitric oxide gas, nitrogen dioxide gas, ozone gas, atomic oxygen, oxygen radicals, and hydroxyl radicals. ,
    2. The semiconductor device manufacture according to claim 1, wherein the second oxygen-containing gas includes at least one selected from the group consisting of oxygen gas, nitrous oxide gas, nitrogen monoxide gas, nitrogen dioxide gas, and ozone gas. Method.
14. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the main element contained in the source gas contains a metalloid element or a metal element, and the oxide film is an oxide film containing the main element.
15. A processing chamber for accommodating the substrate;
    A first supply system for supplying a source gas from a first nozzle to a substrate in the processing chamber;
    A second supply system for supplying a first oxygen-containing gas to a substrate in the processing chamber from a second nozzle different from the first nozzle;
    A third supply system that supplies a second oxygen-containing gas from a third nozzle different from the first nozzle and the second nozzle to the substrate in the processing chamber;
    In the process chamber, the process of supplying the source gas from the first nozzle to the substrate and the process of supplying the first oxygen-containing gas from the second nozzle to the substrate are performed simultaneously. The process of forming an oxide film on the substrate by performing a predetermined number of cycles and supplying the source gas supplies the second oxygen-containing gas from the third nozzle to the substrate. A controller configured to control the first supply system, the second supply system, and the third supply system so as to include a period;
    A substrate processing apparatus.
16. A procedure for supplying a source gas from a first nozzle to a substrate in a processing chamber of the substrate processing apparatus;
    A procedure of supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
    A procedure for forming an oxide film on the substrate by performing a non-simultaneous cycle a predetermined number of times,
    The procedure of supplying the source gas includes a period of supplying a second oxygen-containing gas from a third nozzle different from the first nozzle and the second nozzle to the substrate in the processing chamber. And the steps to
    For causing the substrate processing apparatus to execute the program.

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