JP6741780B2 - Semiconductor device manufacturing method, substrate processing apparatus, and program - Google Patents

Description

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

As one of the steps of manufacturing a semiconductor device (device), a step of supplying a source gas to a substrate and a step of supplying an oxygen-containing gas to the substrate are performed non-simultaneously, by performing a predetermined number of times, A process of forming an oxide film may be performed on the substrate (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 the 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 to the substrate from a second nozzle different from the first nozzle;
A step of forming an oxide film on the substrate by performing a predetermined number of cycles of
There is provided a technique in which the step of supplying the raw material gas includes a period of supplying a second oxygen-containing gas to the substrate from a third nozzle different from the first nozzle and the second nozzle.

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

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, showing a processing furnace portion in a vertical 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, showing a processing furnace portion in a sectional view taken along the line AA of FIG. 1. It is a schematic block diagram of the controller of the substrate processing apparatus suitably used in one embodiment of the present invention, and is a diagram showing a control system of the controller in 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 diagram showing a state of a wafer surface at the time of supplying a raw material gas when performing a film forming process at a relatively low temperature, and (b) is a view showing when supplying a source gas when performing a film forming process at a relatively high temperature FIG. 4 is a diagram showing how Si adsorbed on the wafer surface moves (migration), and FIG. 3C shows that an oxygen gas is supplied together with the source gas when the source gas is supplied at the time of performing a film forming process at a relatively high temperature. It is a figure which shows a mode that migration of Si adsorbed on the wafer surface is suppressed by. (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 a film thickness uniformity of the SiO film in a wafer surface and between wafers in a comparative example. It is a figure which shows the evaluation result regarding sex. FIG. 3 is a schematic configuration diagram of a processing furnace of a substrate processing apparatus preferably used in another embodiment of the present invention, which is a cross-sectional view of a processing furnace portion, in which a reaction tube, a nozzle, an exhaust pipe, a wafer, etc. are extracted. FIG.

<One Embodiment of the Present Invention>
An embodiment of the present invention will be described below 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 adjusting 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 by heat.

Inside the heater 207, a reaction tube 203 is arranged concentrically with the heater 207. The reaction tube 203 is made of, for example, a heat resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with an upper end closed and a lower end opened. Below the reaction tube 203, a manifold 209 is arranged concentrically with the reaction tube 203. The manifold 209 is made of, for example, a metal material such as stainless steel (SUS), and has a cylindrical shape with an open upper end and a lower end. The upper end of the manifold 209 is engaged with the lower end 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 vertically installed like the heater 207. A processing container (reaction container) is mainly configured by the reaction tube 203 and the manifold 209. A processing chamber 201 is formed in the hollow cylindrical portion of the processing container. The processing chamber 201 is configured to be able to accommodate the wafer 200 as a substrate.

A nozzle 249a serving as a first nozzle, a nozzle 249b serving as a second nozzle, and a nozzle 249c serving as a third nozzle are provided in the processing chamber 201 so as to penetrate a sidewall 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 (MFCs) 241a to 241c, which are flow rate controllers (flow rate control units), and valves 243a to 243c, which are opening/closing 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 provided with MFCs 241d to 241f and valves 243d to 243f in this order from the upstream side of the gas flow.

As shown in FIG. 2, the nozzles 249 a to 249 c 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 portion of the inner wall of the reaction tube 203 and above the wafer 200. They are provided so as to rise upward in the arrangement direction. That is, the nozzles 249a to 249c are provided along the wafer arrangement region in a region horizontally surrounding the wafer arrangement region on the side of the wafer arrangement region in which 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) an exhaust port 231a, which will be described later, with the wafer 200 loaded into the processing chamber 201 interposed therebetween in a plan view. The nozzle 249b is arranged near the nozzle 249a. The nozzle 249c is located 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 nozzles 249a and 249c is larger than the distance A between the nozzles 249a and 249b (distance B>distance A). Further, the fan-shaped central angle θ ₂ formed by the nozzles 249a, 249c, and the center 200a of the wafer 200 is smaller than the fan-shaped central angle θ ₁ formed by the nozzles 249a, 249b, and the center 200a of the wafer 200. It is larger (center angle θ ₂ >center angle θ ₁ ).

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

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 250a to 250c are opened so as to face the central portion of the reaction tube 203, and the 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) the exhaust port 231a with the wafer 200 sandwiched therebetween in a plan view. A plurality of gas supply holes 250a to 250c are provided from the lower part to the upper part of the reaction tube 203. The distance A may be considered as the distance between the gas supply holes 250a and 250b, and the distance B may be considered as the distance between the gas supply holes 250a and 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. It is supplied into 201. The raw material gas is a raw material in a gaseous state, for example, a gas obtained by vaporizing a raw material in a liquid state under normal temperature and normal pressure, a raw material in a gaseous state under normal temperature and normal pressure, and the like. 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 raw material gas, for example, hexachlorodisilane (Si ₂ Cl ₆ , abbreviation: HCDS) gas can be used.

As a reactant (reaction gas), for example, an oxygen (O)-containing gas is supplied from the gas supply pipes 232b and 232c into the processing chamber 201 through the MFCs 241b and 241c, the valves 243b and 243c, and the nozzles 249b and 249c, respectively. To be done. In this specification, the O-containing gas supplied from the nozzle 249b in step 2 of the film forming 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 forming process is also referred to. The gas is also referred to as the second O-containing gas. The first O-containing gas acts as an oxidation source (oxidizer, oxidizing gas), that is, an O source. The second O-containing gas acts as a migration suppressing gas that suppresses the migration of Si adsorbed on the wafer 200. As the first and second O-containing gas, for example, oxygen (O ₂ ) gas can be used.

From the gas supply pipe 232a, for example, a hydrogen (H)-containing gas as a reactant (reaction gas) is supplied into the processing chamber 201 via the MFC 241a, the valve 243a, and the nozzle 249a. Although the H-containing gas cannot obtain an oxidizing action by itself, it reacts with the O-containing gas under a specific condition in the film forming process described below to generate an oxidizing species such as atomic oxygen (O). It acts to generate and improve the efficiency of the oxidation process. 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 is supplied as an inert gas through the MFCs 241d to 241f, the valves 243d to 243f, the gas supply pipes 232a to 232c, and the nozzles 249a to 249c, respectively. It is supplied into 201. N ₂ gas acts as a purge gas and a carrier gas.

The gas supply pipe 232a, the MFC 241a, and the valve 243a mainly form a first supply system for supplying the raw material gas. The gas supply pipe 232b, the MFC 241b, and the valve 243b mainly form a second supply system for supplying the first O-containing gas. When the H-containing gas is supplied from the gas supply pipe 232a at the same time as the O-containing gas is supplied 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 uses the MFCs 241a to 241f. The flow rate adjusting operation and the like are configured to be controlled by the controller 121 described later. The integrated type supply system 248 is configured as an integrated type or a divided type integrated unit, and can be attached to and detached from the gas supply pipes 232a to 232f in units of integrated units. It is configured so that 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. Through the exhaust pipe 231, 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 regulator) are provided. A vacuum pump 246 as a vacuum exhaust device is connected. The APC valve 244 can perform vacuum exhaust and vacuum exhaust stop in the processing chamber 201 by opening and closing the valve in a state where the vacuum pump 246 is operated, and further, in a state where the vacuum pump 246 is operated, The pressure inside 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, there is provided a seal cap 219 as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209. The seal cap 219 is made of, for example, a metal material such as SUS and has a disc shape. On the upper surface of the seal cap 219, an O-ring 220b is provided as a seal member that contacts the lower end of the manifold 209. Below the seal cap 219, a rotation mechanism 267 for rotating the boat 217 described later is installed. The rotating shaft 255 of the rotating mechanism 267 penetrates 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 vertically moved 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 moves the wafer 200 in and out (transfers) the wafer 200 by moving the seal cap 219 up and down. Further, below the manifold 209, there is provided a shutter 219s as a furnace port cover capable of airtightly closing the lower end opening of the manifold 209 in a state where the seal cap 219 is lowered and the boat 217 is carried out from the processing chamber 201. There is. The shutter 219s is made of a metal material such as SUS and has a disk shape. On the upper surface of the shutter 219s, an O-ring 220c is provided as a seal member that contacts the lower end of the manifold 209. The opening/closing operation of the shutter 219s (elevating operation, rotating operation, etc.) is controlled by the shutter opening/closing mechanism 115s.

The boat 217 as a substrate support is configured to support a plurality of wafers 200, for example, 25 to 200 wafers 200 in a horizontal posture and in a vertically aligned manner with their centers aligned with each other, that is, in multiple stages. It is configured to be arranged at intervals. The boat 217 is made of, for example, a heat resistant material such as quartz or SiC. Below the boat 217, a plurality of heat insulating plates 218 made of a heat resistant material such as quartz or SiC are supported in multiple stages.

A temperature sensor 263 as a temperature detector is installed in the reaction tube 203. The temperature inside the process chamber 201 has a desired temperature distribution by adjusting the degree of energization to the heater 207 based on the temperature information detected by the temperature sensor 263. The temperature sensor 263 is provided along the inner wall of the reaction tube 203.

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

The storage device 121c is composed of, for example, a flash memory, an HDD (Hard Disk Drive), or the like. In the storage device 121c, a control program for controlling the operation of the substrate processing apparatus, a process recipe in which a procedure, conditions, etc. of the substrate processing to be described later are described are stored in a readable manner. The process recipe is a combination that causes the controller 121 to execute each procedure in the substrate processing described below and obtains a predetermined result, and functions as a program. Hereinafter, process recipes, control programs, and the like are collectively referred to simply as programs. Further, the process recipe is also simply referred to as a recipe. When the word program is used in this specification, it may include only the recipe alone, may include only the control program alone, or may include both of them. The RAM 121b is configured as a memory area (work area) in which programs and data read by the CPU 121a are temporarily stored.

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

The CPU 121a is configured to read and execute the control program from the storage device 121c, and read the recipe from the storage device 121c according to input of an operation command from the input/output device 122. The CPU 121a adjusts the flow rates of various gases by the MFCs 241a to 241f, opens and closes the valves 243a to 243f, opens and closes the APC valve 244, and adjusts the pressure 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 of the shutter 219s.

The controller 121 installs the above-described 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, a semiconductor memory such as a USB memory) 123 into a computer. Can be configured by. The storage device 121c and the external storage device 123 are configured as a computer-readable recording medium. 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 by using communication means such as the Internet or a dedicated line without using the external storage device 123.

(2) Film Forming Process FIG. 4A shows a sequence example of forming a silicon oxide film (SiO film) on a wafer 200 as a substrate by using the substrate processing apparatus described above as one step of a semiconductor device manufacturing process. Will be explained. In the following description, the operation of each part of the substrate processing apparatus is controlled by the controller 121.

In the film forming sequence shown in FIG.
Step 1 of 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,
A non-simultaneous cycle is performed a predetermined number of times (one or more times) to form a SiO film as a film containing Si and O on the wafer 200.

The above step 1 includes a period in which the O ₂ gas is supplied to the wafer 200 from the nozzle 249c. That is, step 1 includes a period in which the HCDS gas and the O ₂ gas are simultaneously supplied to the wafer 200. Further, the above step 2 includes a period in which the O ₂ gas and the H ₂ gas are simultaneously supplied to the wafer 200. The H ₂ gas is supplied from the nozzle 249a arranged near 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 referred to as follows for convenience. The same notation will be used in the description of the modifications and the like below.

(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 "surface of a wafer" is used in this specification, it may mean the surface of the wafer itself or the surface of a predetermined layer or the like formed on the wafer. In this specification, the description of “forming a predetermined layer on a wafer” means directly forming a predetermined layer on the surface of the wafer itself, a layer formed on the wafer, etc. It may mean that a predetermined layer is formed on. 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 opening/closing mechanism 115s moves the shutter 219s to open the lower end opening of the manifold 209 (shutter open). Thereafter, as shown in FIG. 1, the boat 217 supporting 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 (decompressed) by the vacuum pump 246 so that the inside of the processing chamber 201, that is, the space where the wafer 200 exists has a desired pressure (vacuum degree). 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 forming 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 mechanism 267 starts rotating the wafer 200. The exhaust of the processing chamber 201, the heating of the wafer 200, and the rotation are all continuously performed at least until the processing of the wafer 200 is completed.

(Film forming step)
After that, the following steps 1 and 2 are sequentially executed.

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

Specifically, the valves 243a and 243c are opened, and the HCDS gas and the 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, are supplied into the processing chamber 201 through the nozzles 249a and 249c, are mixed in the processing chamber 201, and are exhausted from the exhaust port 231a. At this time, the HCDS gas and the O ₂ gas are supplied (simultaneously) to the wafer 200 at the same time. At this time, the valves 243d and 243f are simultaneously opened, and N ₂ gas is caused to flow 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 HCDS gas and the like from entering the nozzle 249b, the valve 243e is opened and N ₂ gas is flown into the gas supply pipe 232e. The N ₂ gas is supplied into the processing chamber 201 via 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 such that the supply amount Q ₁ of the O ₂ gas (second O-containing gas) in step 1 per cycle is O in step 2 described later per cycle. _The flow rate is set to such a small amount that the supply amount Q _{2 of the two} gases (first O-containing gas) becomes smaller (Q ₁ <Q ₂ ). When the supply time of the O ₂ gas in step 1 is the same as the supply time of the O ₂ gas in step 2, F ₁ is more than the supply flow rate F ₂ of the O ₂ gas supplied from the nozzle 249b in step 2. By making it small, it becomes 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 set to 2 or less, preferably 1/10 or more and 1/5 or less. It should be noted that F ₂ is a flow rate capable of sufficiently oxidizing the first layer formed in Step 1 in Step 2.

When F ₁ is less than 1/20 of F _2, the effect of suppressing the migration of Si described below by O ₂ gas may not be obtained, and the surface roughness of the SiO film formed on the wafer 200 is likely to deteriorate. By setting F ₁ to 1/20 or more of F ₂ , it becomes possible to obtain the effect of suppressing migration and improve the surface roughness of the SiO film. By setting F ₁ to 1/10 or more of F ₂ , it becomes possible to reliably obtain the effect of suppressing migration, and it is possible to surely improve the surface roughness of the SiO film. Here, “surface roughness” means the height difference of the film within the wafer surface, and is synonymous with the surface roughness. The improvement of the surface roughness means that the height difference becomes small 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 , excessive gas phase reaction may occur, and thus the film thickness uniformity of the SiO film formed on the wafer 200 may be easily deteriorated. By setting F ₁ to 1/2 or less of F ₂ , it is possible to cause an appropriate gas phase reaction and improve the film thickness uniformity of the SiO film. By setting F ₁ to ⅕ 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.

The processing conditions in this step are:
Film forming 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): 1-1000 sccm, preferably 1-500 sccm
N ₂ gas supply flow rate (each gas supply pipe): 100 to 10,000 sccm
Film formation temperature (temperature of wafer 200): 450 to 1000°C, preferably 600 to 1000°C, more preferably 700 to 900°C.
Each gas supply time: 1 to 100 seconds, preferably 1 to 50 seconds is exemplified.

When the film forming temperature is lower than 450° C., it becomes 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 formation temperature to 600° C. or higher, it becomes possible to improve the etching resistance of the SiO film formed on the wafer 200 to hydrogen fluoride (HF) and the like. By setting the film forming temperature to 700° C. or higher, it becomes possible to further improve the etching resistance and the like of the SiO film.

When the film forming temperature exceeds 1000° C., 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 are generated in the processing chamber 201, which may deteriorate the quality of the film forming process. By setting the film forming temperature to 1000° C. or less, an appropriate gas phase reaction can be generated, the film thickness uniformity of the SiO film is improved, and the generation of particles in the processing chamber 201 is suppressed. It becomes possible. By setting the film formation temperature to 900° C. or less, it becomes possible to surely improve the film thickness uniformity of the SiO film and to surely suppress the generation of particles in the processing chamber 201.

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

By simultaneously supplying the HCDS gas and the O ₂ gas to the wafer 200 under the above-mentioned conditions, for example, less than one atomic layer (one molecular layer) is formed on the outermost surface of the wafer 200 as the first layer (initial 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 a part of HCDS is decomposed (hereinafter, Si _x Cl _y ) is chemically adsorbed, or HCDS is thermally decomposed. And the like. The Si-containing layer containing Cl may be an adsorption layer of HCDS or Si _x Cl _y (physical adsorption layer or chemical adsorption layer), or may be a Si layer containing Cl. The thickness of the layer formed per cycle can be increased by forming the Si layer containing Cl rather than forming the adsorption layer of HCDS or Si _x Cl _y . In addition, in this specification, the Si-containing layer containing Cl is also simply referred to as a Si-containing layer.

If the thickness of the first layer exceeds several atomic layers, the modification action in step 2 described later cannot reach the entire first layer. Moreover, the minimum value of the thickness of the first layer is less than one atomic layer. Therefore, the thickness of the first layer is preferably 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. You can It is also possible to shorten the time required to form the first layer in step 1. As a result, the processing time per cycle can be shortened, and the total processing time can also be shortened. That is, the film forming rate can be increased. Further, by controlling the thickness of the first layer to be one atomic layer or less, it becomes possible to enhance the controllability of the film thickness uniformity.

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 film formation temperature is set higher, the migration of Si becomes more active, and the surface roughness of the SiO film formed on the wafer 200 is likely to deteriorate. FIG. 5A is a diagram showing a state of the surface of the wafer 200 at the time of supplying the HCDS gas when the film forming process is performed under the condition of 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 and the like 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 the film forming process is performed under the condition of a relatively high temperature of 700° C. or higher. In such a temperature range, migration of Si adsorbed on the wafer 200 becomes significant, and Si agglomerates or the like, so that an uneven structure may be formed on the surface of the first layer. As a result, the interface roughness between the base and the SiO film and the surface roughness of the SiO film may be deteriorated.

In order to solve this problem, in this embodiment, in step 1, the HCDS gas and the O ₂ gas are simultaneously supplied to the wafer 200. By supplying O ₂ gas together with HCDS gas, it is possible to oxidize at least a part of Si at the same time as before or after the adsorption of Si on the wafer 200 and to change it to an oxide (SiO _x ). It will be possible. The Si adsorbed on the wafer 200 is oxidized and becomes difficult to migrate. That is, migration of the Si atoms adsorbed on the wafer 200 is hindered by the O atoms bonded to the Si atoms. As a result, even when the temperature of the wafer 200 is in the above 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 how Si migration is suppressed by supplying O ₂ gas together with HCDS gas. FIG. 5C shows, on an atomic level, a state in which the migration of Si atoms is blocked by the O atoms adjacent to the Si atoms adsorbed on the wafer 200 and the 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. Even when the temperature of the wafer 200 is set in the range of, for example, 700 to 1000° C., the inventors can simultaneously supply the HCDS gas and the O ₂ gas to the wafer 200 in step 1, It has been confirmed that deterioration of the surface roughness of the SiO film can be avoided. The first layer formed on the wafer 200 is a Si-containing layer further containing O in addition to Cl. However, in the present specification, the Si-containing layer containing Cl and O is also referred to as a Si-containing layer containing Cl or simply a Si-containing layer for convenience.

However, when supplying O ₂ gas with HCDS gas, depending on the arrangement of the nozzles used for the supply of O ₂ gas, the film thickness uniformity of the SiO film formed on the wafer 200 may be lowered The inventors have clarified through intensive research. For example, in step 1, when the O ₂ gas is supplied from the nozzle 249b arranged in the vicinity of the nozzle 249a used for supplying the HCDS gas, the in-wafer film thickness distribution of the SiO film formed on the wafer 200 (hereinafter, The in-plane film thickness distribution is the thinnest in the central portion of the wafer 200, and gradually becomes thicker toward the peripheral portion (central concave distribution). WiW) may decrease. Further, in step 1, if the O ₂ gas is supplied from the nozzle 249b, the film thickness uniformity (WtW) of the SiO film between the wafers 200 may decrease.

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

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, 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. This makes it possible to properly suppress the HCDS gas supplied from the nozzle 249a from being consumed before reaching the central portion of the wafer 200. Then, the supply amount of the HCDS gas to the wafer 200 can be made more uniform in the peripheral portion and the central portion of the wafer 200. As a result, the above-described reaction of forming the first layer can be progressed at a uniform rate over the entire area from the peripheral edge portion to the central portion of the wafer 200 and the entire wafer arrangement area. This makes it possible to improve WiW and WtW of the SiO film formed on the wafer 200, respectively.

In addition, in step 1, when the O ₂ gas is supplied from the nozzle 249c, the above-described effect of improving the surface roughness of the SiO film, etc. over the surface of the wafer 200 is compared to the case where the O ₂ gas is supplied from the nozzle 249b. It is also possible to obtain more evenly across the wafers 200. This is the order in step 1, the direction of O ₂ gas supplied from the nozzle 249 c, which compared with the O ₂ gas supplied from the nozzle 249 b, is supplied to the wafer 200 from a more diffuse state Conceivable. In step 1, the O ₂ gas supplied from the nozzle 249c is more likely to be in a diffused state than the O ₂ gas supplied from the nozzle 249b, as described above. This is considered to be because it is arranged at a position farther from the nozzle 249a, and this reduces the probability that the diffusion of O ₂ gas is hindered by collision with HCDS gas, mixing, and the like.

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

As the 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. In addition, as the raw material gas, tetrafluorosilane (SiF ₄ ) gas, tetrabromosilane (SiBr ₄ ) gas, tetraiodosilane (SiI ₄ ) gas, or the like can be used. That is, as a raw material gas, a halosilane raw material gas (chlorosilane compound), a fluorosilane raw material gas (fluorosilane compound), a bromosilane raw material gas (bromosilane compound), an iodosilane raw material gas (iodosilane compound), or another halosilane raw material gas (halosilane compound) is used. Can be used.

In addition, as a raw material gas, tetrakisdimethylaminosilane (Si[N(CH ₃ ) ₂ ] ₄ , abbreviation: 4DMAS) gas, trisdimethylaminosilane (Si[N(CH ₃ ) ₂ ] ₃ H, abbreviation: 3DMAS) gas, bis diethylamino silane _{(Si [N (C 2 H} 5) 2] 2 H 2, abbreviated BDEAS) gas, Bicester fischeri butylamino silane _{(SiH 2 [NH (C 4} H 9)] 2, abbreviated: 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 a Si source but also as an N source and a C source.

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

In addition, as a raw material gas, hexamethyldisiloxane ([(CH ₃ ) ₃ Si] ₂ O) gas, tetramethyldisiloxane ([H(CH ₃ ) ₂ Si] ₂ O) gas, hexachlorodisiloxane ((Cl A siloxane raw material 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 Si and O as a skeleton and is a generic term for compounds having a Si—O—Si bond (siloxane bond). The siloxane raw material gas acts not only as a Si source but also as an O source or an O source and a C source.

As the raw material gas, for example, hexamethyldisilazane _{([(CH 3) 3 Si} ] 2 NH) gas, tetramethyl disilazane _{([H (CH 3) 2} Si] 2 NH) gas, hexachloro disilazane ( A silazane source 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 compounds having a silazane bond such as Si—N—Si bond or Si—N bond. The silazane source gas acts not only as a 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 silane compounds (halosilane compounds, aminosilane compounds, silicon hydride compounds), siloxane compounds, and silazane compounds can be used. Note that siloxane compounds and silazane compounds tend to have higher thermal decomposition temperatures (harder 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, it is possible to suppress excessive thermal decomposition and improve the controllability of the film forming process.

As the second O-containing gas, in addition to O ₂ gas, nitrous oxide (N ₂ O) gas, nitric oxide (NO) gas, nitrogen dioxide (NO ₂ ) gas, ozone (O ₃ ) gas, etc. are 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 point is the same in step 2 described later.

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

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 the H ₂ gas flowing in 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, the O ₂ gas and the 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. Flow rate.

The processing conditions in this step are:
Film forming 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: 1 to 100 seconds, preferably 1 to 50 seconds. The other processing conditions are the same as the processing conditions in step 1.

By simultaneously supplying the O ₂ gas and the 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. As a result, moisture (H ₂ O)-free oxidizing species containing oxygen such as atomic oxygen (O) are generated. Then, the oxidizing process is performed on the first layer formed on the wafer 200 in Step 1 mainly by the oxidizing species. Since the energy of this oxidizing species is higher than the binding energy of the Si—Cl bond or the like contained in the Si-containing layer, the energy of this oxidizing species is applied to the first layer, so that the Si contained in the first layer is -Cl bond and the like are separated. Cl and the like from which the bond with Si has been separated is removed from the layer, and becomes a gaseous substance containing Cl such as Cl ₂ and HCl and is discharged from the processing chamber 201. In addition, a bond of Si, which is left after the bond with Cl or the like is broken, is combined with O contained in the oxidizing species to form a Si—O bond. In this way, the first layer is changed (modified) to the second layer, that is, the SiO layer containing a small amount of impurities such as Cl. According to this oxidation treatment, the oxidizing power can be significantly 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 under a reduced pressure atmosphere, a significant oxidizing power improving effect can be obtained as compared with 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 process 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 may be gases having different molecular structures. When the first O-containing gas and the second O-containing gas have 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 in that it is possible to do so. When the first O-containing gas and the second O-containing gas have different molecular structures, for example, as the second O-containing gas, a substance having an oxidizing power weaker than that of the first O-containing gas is used. This 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 enhanced. 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 is preferably 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 raw material gas or the like is used as the raw material gas, if the 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. You can proceed. That is, the H-containing gas may not be used.

[Performed a predetermined number of times]
An SiO film having a predetermined film thickness is formed on the wafer 200 by performing steps 1 and 2 non-simultaneously, that is, a cycle in which they are alternately performed without synchronization, for a predetermined number of times (n times (n is an integer of 1 or more)) can do. The above cycle is preferably repeated multiple times. That is, the thickness of the second layer formed per cycle is made smaller than the desired film thickness, and the thickness of the SiO film formed by stacking the second layers becomes the desired film thickness. It is preferred to repeat the above cycle multiple times.

(Purge and return to atmospheric pressure)
After the formation of the SiO film is completed, 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 gas, reaction by-products, etc. remaining in the processing chamber 201 are removed from the inside of the processing chamber 201 (after-purging). After that, the atmosphere in the processing chamber 201 is replaced with an inert gas (replacement with an inert gas), 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 from the lower end of the manifold 209 to the outside of the reaction tube 203 while being supported by the boat 217 ( Boat unloading). After the boat is unloaded, 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 carried out of the reaction tube 203 and then taken out of the boat 217 (wafer discharge).

(3) Effects of this Embodiment According to this embodiment, one or more of the following effects can be obtained.

(A) In step 1, the HCDS gas and the O ₂ gas are simultaneously supplied to the wafer 200 to suppress the migration of Si contained in the first layer, and the surface of the SiO film formed on the wafer 200. It is 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 in the range of 450 to 1000° C., but is the case of using a lower temperature (for example, the temperature in the range of 250 to 400° C.). Is obtained as well. However, the migration of Si tends to become more active as the film forming temperature becomes higher. The technical significance of supplying the HCDS gas and the O ₂ gas at the same time in step 1 is that when the film-forming temperature is solely supplied to the wafer 200, the migration of Si contained in the HCDS gas occurs remarkably. The temperature becomes particularly large when the temperature is, for example, in the range of 700 to 1000°C.

(B) In step 1, the O ₂ gas is supplied from the nozzle 249c different from the nozzles 249a and 249b, that is, the O ₂ gas is supplied from the nozzle 249c located farther from the nozzle 249a than the nozzle 249b. By supplying, it becomes possible to improve WiW and WtW of the SiO film formed on the wafer 200, respectively. Further, the above-described effect of improving the surface roughness of the SiO film or the like can be more uniformly obtained within the surface of the wafer 200 and between the wafers 200.

(C) O ₂ gas supply in step 2 is performed by using the nozzle 249b arranged in the vicinity of the nozzle 249a used for supplying H ₂ gas, so that oxidation by the reaction of O ₂ gas and H ₂ gas is performed. 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 surface of the wafers 200 and between the wafers 200. In addition, when the O ₂ gas is supplied from the nozzle 249c apart from the nozzle 249a in step 2, the generation amount of the oxidizing species becomes unstable, and the oxidation treatment performed in step 2 is performed on the surface of the wafer 200 and between the wafers 200. The inventors have already confirmed that there is a case where the uniformity in the above is deteriorated.

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

(E) By forming the SiO film by the alternate supply method in which steps 1 and 2 are not performed at the same time, the step coverage of the SiO film is higher than that in the case where the SiO film is formed by the simultaneous supply method in which steps 1 and 2 are performed simultaneously. The film thickness controllability, the in-plane film thickness uniformity, and the like can be improved. Such a film forming method is particularly effective when the lower surface of the film forming process has a 3D structure such as a line and space shape, a hole shape, or a fin shape.

(F) By setting the temperature of the wafer 200 in the above-mentioned temperature range during the film forming process, it becomes possible to form a SiO film having high quality film characteristics. For example, by setting the film formation temperature to a temperature in the range of 450 to 1000° C., the film formation temperature of the SiO film is lower than that in the case of a film formation temperature of less than 450° C., for example, a temperature in the range of 250 to 400° C. It is also possible to improve etching resistance and insulation performance, extend service life, and reduce the interface electron trap density that affects the response speed of the transistor.

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

(4) Modified Example The film forming sequence in this embodiment can be modified as in the modified examples described below.

(Modification 1)
The supply of the O ₂ gas from the nozzle 249c may be performed not only during the HCDS gas supply period in step 1 but also during another period. For example, as shown in FIG. 4B, the supply of O ₂ gas from the nozzle 249c is interrupted throughout the cycle only during the supply period of the HCDS gas in step 1, that is, not intermittently. Instead, it may be performed continuously. Also in this modification, the same effect as that of 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 the present modification, deactivation of unreacted HCDS (residual HCDS) attached to the inner wall of the processing chamber 201 is promoted, and residual HCDS is retained. It is possible to prevent the film formation process from being adversely affected. The supply flow rate of the O ₂ gas from the nozzle 249c can be the same as the supply flow rate of the O ₂ gas in step 1 described above.

(Modification 2)
As in the film forming sequence described below, the SiO film may be formed under the medium temperature condition by using the aminosilane raw material gas and the O ₃ gas. Alternatively, a SiO film may be formed under low temperature conditions using an aminosilane raw material gas and plasma-excited O ₂ gas (hereinafter, also referred to as O ₂ ^* ). Further, the above silicon hydride gas may be used instead of the aminosilane raw material 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 in the film formation sequence shown below, N-containing gas such as ammonia (NH ₃ ) gas or N- and C-containing gas such as triethylamine ((C ₂ H ₅ ) ₃ N, abbreviated as TEA) gas is used as a 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 further used, and a silicon oxynitride film (SiON film) or a silicon oxycarbide film is formed on the wafer 200. A film (SiOC film), a silicon oxycarbonitride film (SiOCN film), a silicon boric acid carbonitride film (SiBOCN film), a silicon boric acid oxynitride 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 embodiments of the present invention have 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 spirit of the invention.

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

For example, as a raw material, titanium tetrachloride (TiCl ₄ ) gas, hafnium tetrachloride (HfCl ₄ ) gas, tantalum pentachloride (TaCl ₅ ) gas, trimethylaluminum (Al(CH ₃ ) ₃ , abbreviation: TMA) gas, etc. are used. , H ₂ O gas is used as the first O-containing gas, O ₂ gas is used as the second O-containing gas, and the TiO film, the HfO film, and the TaO film are formed on the wafer 200 by the following film formation sequence. The present invention can be suitably applied to the case of 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 processing at this time can be the same as the processing procedures and processing conditions of the above-described embodiment and modified examples. Even in these cases, the same effects as those of the above-described embodiment and modifications can be obtained. That is, the present invention is preferably applied to the case of forming a metalloid oxide film containing a metalloid element such as Si as a main element, and the case of forming a metal oxide film containing various metal elements described above as a main element. be able to.

It is preferable that the recipe used for the substrate processing is individually prepared according to the processing content and stored in the storage device 121c via the telecommunication line or the external storage device 123. Then, when starting the processing, it is preferable that the CPU 121a appropriately selects an appropriate recipe from a plurality of recipes stored in the storage device 121c according to the content of the substrate processing. As a result, it becomes possible to form films of various film types, composition ratios, film qualities, and film thicknesses with good reproducibility with one substrate processing apparatus. Further, the burden on the operator can be reduced, and the processing can be started promptly while avoiding an operation error.

The above-described recipe is not limited to the case of newly creating the recipe, but may be prepared by changing an existing recipe already 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 in which the recipe is recorded. Further, the input/output device 122 included in the existing substrate processing apparatus may be operated to directly change the existing recipe already installed in the substrate processing apparatus.

In the above-mentioned embodiment, the example using the reaction tube configured as a single tube has been described. However, the invention is not limited to the embodiments described above. For example, as shown in the sectional view of the vertical processing furnace in FIG. 7, the reaction tube may be configured 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 the first buffer chamber on the side far from the exhaust port (the buffer chamber at a position facing the exhaust port with the center of the wafer in between). ), the first and second nozzles are provided in the same arrangement as in the above-described embodiment, and the third nozzles are provided in the second buffer chamber on the side closer to the exhaust port in the same arrangement as in the above-described embodiment. .. The exhaust pipe connected to the outer tube exhausts the annular space between the inner tube and the outer tube, thereby exhausting the processing chamber formed inside the inner tube. 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 effect as that 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 once has been described. The present invention is not limited to the above-described embodiments, and can be suitably applied to, for example, the case where a film is formed using a single-wafer processing apparatus that processes one or several substrates at a time. Further, in the above-described embodiment, an example of forming a film using the substrate processing apparatus having the 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 the 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 under the same sequence and processing conditions as those of the above-described embodiment and modification, and the same effects as these can be obtained.

Further, the above-described embodiments and modified examples can be appropriately combined and used. The processing procedure and the processing condition at this time can be the same as the processing procedure and the processing condition of the above-described embodiment, for example.

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

As an example, a substrate processing apparatus equipped with the vertical processing furnace shown in FIG. 7 was used to form a SiO film on a wafer according to the film forming sequence shown in FIG. In step 1, the HCDS gas was supplied from the first nozzle and the O ₂ gas (migration suppressing gas) was supplied from the third nozzle. In step 2, O ₂ gas (oxidizer) was supplied from the second nozzle and H ₂ gas was supplied from the first nozzle. The processing condition in each step was set within the processing condition range described in the above embodiment.

As a comparative example, a substrate processing apparatus equipped with the vertical processing furnace shown in FIG. 7 was used to form a SiO film on the wafer according to the film forming sequence shown in FIG. In step 1, O ₂ gas (migration suppressing gas) was supplied from the second nozzle. The nozzle for supplying another gas, the processing procedure, and the processing conditions were the same as those in the example.

Then, the in-wafer film thickness uniformity [WiW] (±%) and the wafer-to-wafer film thickness uniformity [WtW] (±%) of the SiO film 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 figures, TOP, CEN, and BTM indicate the position of the wafer in the wafer arrangement region, that is, the position of the wafer is the upper portion, the central portion, and the lower portion in the wafer arrangement region, respectively. WiW represents the degree of variation in the film thickness distribution within the wafer surface, and the smaller the value, the better the film thickness uniformity within the wafer surface. Further, WtW indicates the degree of variation in the film thickness distribution between the wafers, and the smaller the value, the better the film thickness uniformity between the wafers.

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

200 wafers (substrates)
249a nozzle (first nozzle)
249b nozzle (second nozzle)
249c nozzle (third nozzle)

Claims (19)

Supplying a source gas from the first nozzle to the substrate,
Supplying a first oxygen-containing gas to the substrate from a second nozzle different from the first nozzle;
A step of forming an oxide film on the substrate by performing a predetermined number of cycles of
Step of supplying the source gas to the substrate, seen including a period for supplying the second oxygen-containing gas from different third nozzles respectively from the first nozzle and the second nozzle,
A method of manufacturing a semiconductor device , wherein a distance B between the first nozzle and the third nozzle is set larger than a distance A between the first nozzle and the second nozzle . Supplying a source gas from the first nozzle to the substrate,
Supplying a first oxygen-containing gas to the substrate from a second nozzle different from the first nozzle;
A step of forming an oxide film on the substrate by performing a predetermined number of cycles of
The step of supplying the source gas includes a period of supplying a second oxygen-containing gas from the third nozzles different from the first nozzle and the second nozzle to the substrate,
Wherein the third nozzle, the manufacturing method of the second nozzle semiconductors devices you located at a distance from the first nozzle than. Supplying a source gas from the first nozzle to the substrate,
Supplying a first oxygen-containing gas to the substrate from a second nozzle different from the first nozzle;
A step of forming an oxide film on the substrate by performing a predetermined number of cycles of
The step of supplying the source gas includes a period of supplying a second oxygen-containing gas from the third nozzles different from the first nozzle and the second nozzle to the substrate,
The central angle θ _{2 of the} sector formed by the centers of the first nozzle, the third nozzle, and the substrate is defined as the central angle of the sector formed by the centers of the first nozzle, the second nozzle, and the substrate. method of manufacturing a semi-conductor device you greater than theta _1. The semiconductor device according to claim 1, wherein the supply amount of the second oxygen-containing gas per cycle is made smaller than the supply amount of the first oxygen-containing gas per cycle. Production method. The method of manufacturing a semiconductor device according to claim 4 , wherein the supply flow rate of the second oxygen-containing gas per cycle is made smaller than the supply flow rate of the first oxygen-containing gas per cycle. The semiconductor according to claim 4 , wherein the supply flow rate of the second oxygen-containing gas per cycle is set to 1/20 or more and 1/2 or less of the supply flow rate of the first oxygen-containing gas per cycle. Device manufacturing method. The manufacturing of the 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. Method. The semiconductor device according to claim 1, wherein a supply time of the second oxygen-containing gas per cycle is set shorter than a supply time of the first oxygen-containing gas per cycle. Production method. Step of supplying the first oxygen-containing gas, to the substrate, according to claim 1, comprising a period for supplying said first oxygen-containing gas and a hydrogen-containing gas at the same time Of manufacturing a semiconductor device of. 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. The method for manufacturing a semiconductor device according to claim 1 , wherein the source gas contains at least one selected from the group consisting of a silane compound, a siloxane compound, and a silazane compound. The first oxygen-containing gas contains 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. ,
The second oxygen-containing gas, oxygen gas, nitrous oxide gas, any one of the preceding claims, including nitric oxide gas, nitrogen dioxide gas, and at least one selected from the group consisting of ozone gas A method of manufacturing a semiconductor device according to item 1. 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. A processing chamber for accommodating the substrate,
A first supply system for supplying a source gas from a first nozzle to the substrate in the processing chamber;
A second supply system for supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A third supply system for 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;
In the processing chamber, a process of supplying the source gas from the first nozzle to the substrate and a process of supplying the first oxygen-containing gas from the second nozzle to the substrate are performed non-simultaneously. The process of forming an oxide film on the substrate is performed by performing the cycle a predetermined number of times, and the process of supplying the source gas supplies the second oxygen-containing gas from the third nozzle to the substrate. A control unit configured to control the first supply system, the second supply system, and the third supply system so as to include a period;
Have a,
A substrate processing apparatus in which 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 . A processing chamber for accommodating the substrate,
A first supply system for supplying a source gas from a first nozzle to the substrate in the processing chamber;
A second supply system for supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A third supply system for 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;
In the processing chamber, a process of supplying the source gas from the first nozzle to the substrate and a process of supplying the first oxygen-containing gas from the second nozzle to the substrate are performed non-simultaneously. The process of forming an oxide film on the substrate is performed by performing the cycle a predetermined number of times, and the process of supplying the source gas supplies the second oxygen-containing gas from the third nozzle to the substrate. A control unit configured to control the first supply system, the second supply system, and the third supply system so as to include a period;
Have
A substrate processing apparatus wherein the third nozzle is arranged at a position farther from the first nozzle than the second nozzle. A processing chamber for accommodating the substrate,
A first supply system for supplying a source gas from a first nozzle to the substrate in the processing chamber;
A second supply system for supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A third supply system for 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;
In the processing chamber, a process of supplying the source gas from the first nozzle to the substrate and a process of supplying the first oxygen-containing gas from the second nozzle to the substrate are performed non-simultaneously. The process of forming an oxide film on the substrate is performed by performing the cycle a predetermined number of times, and the process of supplying the source gas supplies the second oxygen-containing gas from the third nozzle to the substrate. A control unit configured to control the first supply system, the second supply system, and the third supply system so as to include a period;
Have
A fan-shaped central angle θ formed by the centers of the first nozzle, the third nozzle, and the substrate _Two Is a central angle θ of a sector formed by the centers of the first nozzle, the second nozzle, and the substrate. ₁ Substrate processing equipment to make larger than. A procedure for supplying a source gas from the first nozzle to the substrate in the processing chamber of the substrate processing apparatus;
A step of supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A step of forming an oxide film on the substrate by performing a predetermined number of non-simultaneous cycles,
The procedure of supplying the source gas may include a period of supplying a second oxygen-containing gas to the substrate in the processing chamber from a third nozzle different from the first nozzle and the second nozzle. The steps to
A program to be executed by a computer by the computer in a state where a distance B between the first nozzle and the third nozzle is set larger than a distance A between the first nozzle and the second nozzle . A procedure for supplying a source gas from the first nozzle to the substrate in the processing chamber of the substrate processing apparatus;
A step of supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A step of forming an oxide film on the substrate by performing a predetermined number of non-simultaneous cycles,
The procedure of supplying the source gas may include a period of supplying a second oxygen-containing gas to the substrate in the processing chamber from a third nozzle different from the first nozzle and the second nozzle. The steps to
A program that causes the substrate processing apparatus to execute the program by a computer in a state in which the third nozzle is located farther from the first nozzle than the second nozzle. A procedure for supplying a source gas from the first nozzle to the substrate in the processing chamber of the substrate processing apparatus;
A step of supplying a first oxygen-containing gas from a second nozzle different from the first nozzle to the substrate in the processing chamber;
A step of forming an oxide film on the substrate by performing a predetermined number of non-simultaneous cycles,
The procedure of supplying the source gas may include a period of supplying a second oxygen-containing gas to the substrate in the processing chamber from a third nozzle different from the first nozzle and the second nozzle. The steps to
A fan-shaped central angle θ formed by the centers of the first nozzle, the third nozzle, and the substrate _Two Is a central angle θ of a sector formed by the centers of the first nozzle, the second nozzle, and the substrate. ₁ A program to be executed by the computer by the computer in a state of being made larger than the above.