JP6062306B2 - Surface treatment equipment - Google Patents

Description

  The present invention relates to a technique of a surface treatment apparatus that performs surface treatment of a substrate.

  For example, in order to manufacture a semiconductor element or the like, a raw material fluid such as an appropriate reaction gas is supplied onto the substrate to form a semiconductor layer, an insulating film, a conductor layer, or the like on the substrate, or the surface of the substrate is Etching or forming a coating material is performed. Such treatment is widely performed in addition to the manufacture of semiconductor elements, and these treatments can be referred to as surface treatment in a broad sense, and an apparatus that performs this surface treatment can be referred to as a surface treatment device in a broad sense.

  For example, an epitaxial apparatus for epitaxially growing a semiconductor layer on a semiconductor wafer or an insulator wafer, a vapor deposition (CVD) apparatus for depositing an insulating film such as an appropriate oxide film on the semiconductor wafer, or formed on a semiconductor wafer A dry etching apparatus or the like that removes the formed thin film or the like is a surface treatment apparatus in a broad sense.

  If surface treatment is performed for a long time using such a surface treatment apparatus, for example, during mass production of the product, surface treatment is also performed on the inner wall of the surface treatment apparatus, and deposits may accumulate on the inner wall of the surface treatment apparatus. is there. Then, when the deposit is peeled off and adheres to the substrate, there is a possibility that the quality of the object to be processed is deteriorated.

  In order to remove such deposits chemically or physically, a cleaning process is conventionally performed after the surface treatment. The cleaning process includes a method of contacting a deposit deposited in the surface treatment apparatus with a cleaning process fluid and removing the deposit by a chemical reaction, a method of removing the surface treatment apparatus, and a method of cleaning. However, when such a cleaning process is performed, the operating rate of the apparatus is reduced and the surface treatment cost is increased.

  For example, in Patent Documents 1 and 2, a surface treatment that reduces the accumulation of deposits by supplying an inert gas to the inner wall of the surface treatment apparatus and suppressing contact of the reactive gas with the inner wall of the surface treatment apparatus. An apparatus is disclosed.

  Although the purpose is not to suppress the accumulation of deposits on the inner wall of the surface treatment apparatus, for example, in Patent Document 3, an inhibition gas that inhibits the reaction of the reaction gas is supplied to a sample holder that holds the substrate, and the substrate And a surface treatment apparatus that suppresses sticking of the sample holding table to the sample holder.

  For example, in Patent Document 4, in a cross-flow type surface treatment apparatus that cross-flows a reactive gas, a surface treatment that reduces deposition of deposits on the upper wall by flowing an inert gas in the vicinity of the upper wall facing the substrate. An apparatus is disclosed. Further, for example, Patent Document 5 discloses a cross-flow type surface treatment apparatus that reduces the deposition of deposits on the upper wall by flowing an etching gas in the vicinity of the upper wall facing the substrate.

JP 2002-16008 A Japanese Patent Laid-Open No. 10-50615 JP 2010-153483 A JP-A-6-338466 JP 2011-21278 A

  In the surface treatment apparatuses of Patent Documents 1, 2, and 4, since the concentration of the reaction gas that contacts the inner wall of the surface treatment apparatus is reduced by an inert gas, deposits accumulate on the inner wall of the surface treatment apparatus over time. It will be done.

  The surface treatment apparatus of Patent Document 3 is intended to suppress the substrate and the sample holder from sticking to each other with deposits. Therefore, the deposit on the inner wall of the surface treatment apparatus is left as it is. It is difficult to apply it to a means for suppressing the deposition of slag.

  In the surface treatment apparatus of Patent Document 5, deposition of deposits on the inner wall of the surface treatment apparatus is suppressed, but the influence of the etching gas on the substrate is not taken into consideration, and the film formation rate is reduced or the film formation is performed. The surface treatment performance such as the in-plane uniformity of the surface may be degraded.

  The objective of this invention is providing the surface treatment apparatus which can suppress the fall of the surface treatment performance of a board | substrate, and can suppress deposition of the deposit on the inner wall of a surface treatment apparatus.

  The surface treatment apparatus of the present invention includes a reaction vessel, a sample holding table that is provided inside the reaction vessel and holds and rotates a substrate that is an object to be surface-treated, and the sample holding table in the reaction vessel. A raw material fluid inflow portion that is provided above and supplies a raw material fluid to the substrate, and provided on a side of the sample holder in the reaction vessel, and after the raw material fluid performs a surface treatment on the substrate A raw material fluid discharge part for discharging the raw material waste fluid, an introduction part for introducing a sub-fluid containing an etching fluid into the raw material fluid discharge part in the reaction vessel, and the raw material fluid performs surface treatment on the substrate A supply means for supplying the sub-fluid to the introduction part, and the source fluid discharge part surrounds a lateral outer periphery of the sample holder from a lower end of the source fluid inflow part. Under the raw material fluid The raw material flowing through the raw material fluid inflow portion so that the sub-fluid flows along an inner wall of the raw material fluid discharge portion. It is arranged perpendicular or substantially perpendicular to the fluid flow direction.

  In the surface treatment apparatus, the flow rate of the etching fluid in the sub-fluid supplied by the supply unit is such that the etching fluid in a mixed state of the raw material fluid and the sub-fluid on the inner wall of the discharge portion. Is preferably set to be equal to or higher than the concentration of the etching fluid at which the film formation rate obtained in advance is zero.

  In the surface treatment apparatus, it is preferable that the pressure of the raw material fluid flowing through the raw material fluid inflow portion is 0.9 atm or more.

  In the surface treatment apparatus, the concentration of the raw material fluid flowing in the raw material fluid inflow portion is preferably 1% or more.

  ADVANTAGE OF THE INVENTION According to this invention, the surface treatment apparatus which can suppress the fall of the surface treatment performance of a board | substrate and can suppress the accumulation of the deposit on the inner wall of a surface treatment apparatus can be provided.

It is a schematic diagram for demonstrating an example of a structure of the surface treatment apparatus which concerns on this embodiment. (A) and (B) are an example of a mechanism that hinders the deposition of deposits on the inner wall by the etching fluid. It is a figure which shows an example of the result of the HCl density | concentration on a board | substrate in which the film-forming speed | rate of a board | substrate becomes zero with respect to each raw material density | concentration on a board | substrate on a certain temperature condition. (A) is a figure which shows HCl concentration distribution in the raw material fluid discharge part of Example 1-1, (B) is a figure which shows the mole fraction of the fluid in the raw material fluid discharge part in the distance from A point. is there. (A) is a figure which shows HCl concentration distribution in the raw material fluid discharge part of Comparative Example 1-1, (B) is a figure which shows HCl concentration distribution in the raw material fluid discharge part of Comparative Example 2-1. It is a figure which shows the simulation result of the Si film-forming speed | rate on the board | substrate of Example 1-1 and Comparative Examples 1-1 and 2-1.

The surface treatment apparatus described below supplies a surface treatment raw material fluid onto the substrate, forms a semiconductor layer, an insulating film, a conductor layer, etc. on the substrate, or forms a coating material. The process is performed. For example, for the purpose of epitaxial growth of a silicon single crystal, a mixed gas of SiHCl ₃ + H ₂ or the like is used as a raw material fluid for surface treatment.

  FIG. 1 is a schematic diagram for explaining an example of the configuration of the surface treatment apparatus according to the present embodiment. As shown in FIG. 1, the surface treatment apparatus 1 includes a reaction vessel 10 and a cylindrical sample holder 12 that is provided inside the reaction vessel 10 and holds a substrate 18 that is an object to be surface-treated. Prepare. In FIG. 1, the direction axis parallel to the direction in which the raw material fluid 32 flows toward the substrate 18 is indicated as the y axis, and the direction axis parallel to the surface of the substrate 18 is indicated as the x axis. In the following description, when referring to the upper side and the lower side, in the direction along the y-axis, the upstream direction in which the raw material fluid 32 flows is upward, and the downstream direction is downward. Generally, the direction from the top to the bottom is the vertical direction (gravity direction).

  A sample holding mechanism (not shown) is provided on the upper surface of the cylindrical sample holding table 12, and a substrate 18 such as a silicon wafer on which a silicon single crystal is grown is held by the sample holding mechanism. Examples of the sample holding mechanism include a recess that matches the outer shape of the substrate 18, a mechanism that mechanically fixes the outer periphery of the substrate 18, a mechanism that sucks and fixes the substrate 18 in a vacuum, and the like.

  It is desirable that a heater (not shown) such as a heater is installed in the cylindrical sample holder 12 and the sample holder 12 is heated to a predetermined temperature by the heater. For example, a concave portion is formed on the lower surface side of the cylindrical sample holding table 12, a heater or the like is accommodated in the concave portion, and the heater is energized to control the sample holding table 12 to a predetermined temperature.

  The cylindrical sample holder 12 is provided with a rotating unit 24. The rotating unit 24 is configured by a motor, a power transmission mechanism for connecting the sample holder 12 and the motor, and the like, and is a rotating mechanism having a function of rotating around a rotation axis perpendicular to the plane of the sample holder 12.

  A partition wall 14 is preferably provided around the side of the sample holder 12 of the present embodiment. The partition wall 14 can protect the sample holder 12 and suppress turbulent flow of the raw material fluid 32 and the like caused by the rotation of the sample holder 12.

  A cylindrical portion 28 provided above the sample holder 12 in the reaction vessel 10 serves as a raw material fluid inflow part for supplying the raw material fluid 32 to the substrate 18 on the sample holder 12 (hereinafter referred to as the raw material fluid inflow part). 28).

  In the reaction vessel 10, the flow path provided on the side of the sample holder 12 (in the present embodiment via the partition wall 14) is a raw material fluid discharge unit 30. The raw material fluid discharge unit 30 is a used fluid after the surface treatment is performed on the substrate 18 while the raw material fluid 32 supplied from the raw material fluid inflow portion 28 toward the substrate 18 flows along the surface of the substrate 18. The flow path has a function of flowing out from the side of the sample holder 12 as a raw material waste fluid.

  The shape of the raw material fluid discharge part 30 of the present embodiment is formed on the downstream side of the raw material fluid 32 from the lower end of the raw material fluid inflow part 28 so as to surround the lateral outer periphery of the sample holder 12 (via the partition wall 14). It is an annular flow path that expands toward you. That is, the raw material fluid discharge part 30 of the present embodiment is a streamlined flow path that spreads out in an umbrella shape or a skirt shape when viewed from the raw material fluid inflow part 28 of the reaction vessel 10. By making the raw material fluid discharge part 30 into a streamline type flow path, it is possible to further suppress the raw material fluid 32 from flowing backward in the raw material fluid discharge part 30 and mixing into the raw material fluid inflow part 28.

A reaction gas supply device 16 having a function of supplying a raw material fluid 32 for performing a surface treatment on the substrate 18 at a desired pressure and flow rate is installed in the raw material fluid inflow portion 28 of the reaction vessel 10. As the raw material fluid 32 for crystallizing the silicon single crystal, for example, a reactive gas (SiHCl ₃ ) alone or a mixed gas of reactive gas (SiHCl ₃ ) + carrier gas (H ₂ ) is used.

  It is desirable to install a discharge treatment device 20 having a function of performing a suitable discharge detoxification process and discharging the fluid passing through the raw material fluid discharge unit 30 to the outside at the discharge port of the raw material fluid discharge unit 30 of the reaction vessel 10. . Moreover, it is desirable that the discharge processing device 20 includes a discharge pump or the like for easily guiding the fluid to the outside. Examples of the discharge detoxification process include a dilution process and a removal process that removes harmful components contained in the fluid passing through the raw material fluid discharge unit 30 by a precipitation reaction or the like.

  In the raw material fluid discharge part 30 of the present embodiment, a secondary fluid introduction part 26 that introduces the secondary fluid 22 containing the etching fluid into the raw material fluid discharge part 30 is provided. The subfluid introduction portion 26 of the present embodiment is configured so that the flow direction of the raw material fluid 32 flowing through the raw material fluid inflow portion 28 (the y axis in FIG. 1) so that the subfluid 22 is discharged along the inner wall of the raw material fluid discharge portion 30. ) With respect to the vertical or substantially vertical direction. Here, “substantially perpendicular” means that the sub-fluid 22 is inclined with respect to the y-axis of FIG. As shown in FIG. 1, it is naturally understood that the sub-fluid introduction unit 26 is installed on the upstream side from a place where deposits are assumed to be easily deposited.

A sub-fluid supply device 34 having a function of supplying the sub-fluid 22 containing the etching fluid at a predetermined flow rate is connected to the sub-fluid introduction portion 26. As the auxiliary fluid 22, for example, an etching fluid alone, a mixed gas of etching fluid + carrier gas (H ₂ ), or the like is used. The etching fluid in this specification is a gas or liquid that reacts with the deposit to remove (etch) the deposit, and examples thereof include HCl gas and fluorine-based gas. As will be described later, HCl gas, fluorine-based gas, and the like mainly have a function as etching for removing deposits, but are also considered to have a function of adsorbing on the surface of the deposits.

  Next, the operation of the surface treatment apparatus 1 shown in FIG. 1 will be described.

  First, the sample holder 12 is rotated by the rotating unit 24, and the sample holder 12 is heated by a heater (not shown). Then, the raw material fluid 32 is supplied from the reaction gas supply device 16 and the auxiliary fluid 22 (etching fluid) is supplied from the auxiliary fluid supply device 34. The raw material fluid 32 is brought into contact with the substrate 18 through the raw material fluid inflow portion 28 and surface treatment is performed. The raw material fluid 32 after the surface treatment passes through the raw material fluid discharge unit 30 as a raw material exhaust fluid, and is discharged out of the system from the discharge port via the discharge processing device 20 and the like. Normally, when such surface treatment is continued, the surface treatment is also performed on the inner wall of the raw material fluid discharge section 30, and deposits are generated and deposited on the inner wall. However, in the present embodiment, the auxiliary fluid 22 discharged from the raw material fluid discharge portion 30 arranged perpendicularly or substantially perpendicular to the flow direction of the raw material fluid 32 flowing through the raw material fluid inflow portion 28 (y axis in FIG. 1). However, since it flows along the inner wall of the raw material fluid discharge part 30, accumulation of the deposit on the inner wall of the raw material fluid discharge part 30 can be suppressed. Moreover, since the subfluid 22 flows along the inner wall of the raw material fluid discharge part 30, it is suppressed that it flows to the board | substrate 18 side. As a result, a decrease in surface treatment performance on the substrate 18 can be suppressed. Below, an example of the mechanism which suppresses deposition of the deposit of an inner wall by the etching fluid is demonstrated.

FIGS. 2A and 2B show an example of a mechanism that hinders the deposition of deposits on the inner wall by the etching fluid. When the etching fluid is supplied to the raw material fluid discharge portion, as shown in FIG. 2A, the deposit deposited on the inner wall of the raw material fluid discharge portion is removed (etched) by the etching fluid supplied to the raw material fluid discharge portion. Therefore, the accumulation of the deposit on the inner wall is hindered. For example, when a mixed gas of SiHCl ₃ + H ₂ is used as the raw material fluid and HCl gas is used as the etching fluid, the Si film generated on the inner wall reacts with the HCl gas to generate SiCl ₂ and the Si film is removed. . The HCl gas as an etching fluid mainly has a function of etching deposits. For example, as shown in FIG. 2B, it also has a function of adsorbing Cl atoms on the surface of the Si film. It is thought that it is equipped.

  In this embodiment, the flow rate of the etching fluid in the subfluid 22 supplied into the raw material fluid discharge unit 30 is the etching fluid in the mixed state of the raw material fluid 32 and the subfluid 22 on the inner wall of the raw material fluid discharge unit 30. Is set to be equal to or higher than the concentration of the etching fluid at which the film formation rate obtained in advance is zero. This will be specifically described below.

  FIG. 3 shows an example of the result of the HCl concentration on the inner wall at which the film formation rate on the inner wall becomes zero for each raw material concentration (in the raw material fluid) on the inner wall for a certain temperature condition of the inner wall. FIG. FIG. 3 shows how much HCl concentration on the inner wall is necessary to make the film forming rate on the inner wall zero for each raw material concentration on the inner wall. That is, on the inner wall in question, when the HCl concentration in the mixed state of the raw material fluid and the sub-fluid of a certain raw material concentration is the HCl concentration on or above the curve shown in FIG. Become zero.

  FIG. 3 is an example in which the deposition rate of the substrate for each raw material concentration on the substrate with respect to a certain inner wall temperature condition is zero, and therefore, when the temperature condition of the inner wall in question changes, FIG. A similar graph may be created. The HCl concentration at which the substrate deposition rate becomes zero may be set to a value on the curve shown in FIG. 3 or the like, or may be set to a value above the curve. Then, for example, the concentration of the raw material at the inner wall of the raw material fluid discharge unit 30 at a flow rate of a certain raw material fluid is obtained by simulation and the like, and the HCl concentration at which the film formation rate becomes zero is obtained by inputting the raw material concentration into the aforementioned map. It is done.

  Then, on the inner wall of the raw material fluid discharge part, the concentration of the etching fluid in the mixed state of the raw material fluid and the sub-fluid is the concentration of the etching fluid (for example, HCl concentration) at which the film formation rate determined in advance as described above becomes zero. As described above, the flow rate of the etching fluid (HCl gas) in the sub-fluid supplied to the raw material fluid discharge unit is set. This flow rate is obtained by calculation such as simulation. Thereby, deposition of the deposit on the inner wall of the raw material fluid discharge part is further suppressed. The flow rate of the etching fluid set in this way is obtained by calculation such as simulation.

  The HCl concentration at which the film formation speed is zero as an example in FIG. 3 can be obtained by using the following equation assuming film formation at the substrate position. Formula 1 is a continuous formula, Formula 2 is a momentum equation, Formula 3 is an energy formula, Formula 4 is a transport equation for each chemical species, Formula 5 is a state equation (low Mach) Number approximation).

The second term on the right side of Equation 4 expresses the Soret effect, and is an approximate expression using the thermal diffusion ratio.

Here, τ _ij and M in the above expression are expressed by the following expressions 6 and 7.

In the above equation, ρ is density, u _j is velocity in j direction, P ₀ is average pressure, p is pressure (deviation from average pressure), g is gravity, T is temperature, C _p is specific heat, Y _i : The mass fraction of the i component, R ₀ is the universal gas constant, M _k is the molecular weight of the k component, M is the average molecular weight of the mixed fluid, (w _g ) _i is the production rate of the i component by the gas phase reaction, (w _s ) _i is the generation rate of the i component due to the surface reaction, μ is the viscosity coefficient, λ is the thermal conductivity, D _i is the diffusion coefficient of the i component, α _ik is the thermal diffusion ratio between the i component and the k component, and D _ik is the i component And k component, t is time, and _xj is spatial coordinates.

  The HCl concentration at which the film formation rate becomes zero can be derived by solving the above equations, but has been transformed into a one-dimensional calculation formula in a direction perpendicular to the substrate processing surface disclosed in Japanese Patent Application Laid-Open No. 2011-29592. Assuming the source concentration in the source fluid above, when the hydrogen, which is the carrier gas in the source fluid, is gradually replaced with HCl, the HCl concentration at which the film formation rate on the substrate becomes zero is set to It can be similarly derived by plotting for each temperature condition.

The total flow rate of the secondary fluid is preferably set to a flow rate sufficient to push back the mixed fluid that flows backward in order to prevent the mixed fluid (raw material fluid and secondary fluid) from flowing back to the substrate. Here, when the secondary fluid is, for example, a mixed gas of an etching fluid and a carrier gas such as H ₂ gas, the total flow rate of the secondary fluid is the sum of the flow rate of the etching fluid and the flow rate of the carrier gas. Become. Whether or not the mixed fluid reaches the substrate in a backward flow can be determined by, for example, checking whether or not the radial distribution of the film formation speed on the substrate is uniform in the simulation.

  As described above, the shape of the raw material fluid discharge part 30 is an annular flow channel that extends from the lower end of the raw material fluid inflow part 28 toward the downstream side of the raw material fluid 32 so as to surround the outer periphery of the sample holder 12. (I.e., the raw material fluid discharge part 30 is a streamlined flow path that spreads out in an umbrella shape or a skirt shape when viewed from the raw material fluid inflow part 28 of the reaction vessel 10) and flows through the raw material fluid inflow part 28. By arranging the sub-fluid 22 discharged from the raw material fluid discharge part 30 along the inner wall of the raw material fluid discharge part 30 by being arranged perpendicular or substantially perpendicular to the flow direction of the raw material fluid 32 (y axis in FIG. 1). Since deposition of deposits on the inner wall of the raw material fluid discharge unit 30 is suppressed, and the subfluid 22 is prevented from flowing to the substrate 18 side, the film formation speed is reduced or the film formation is in-plane uniformity. Deterioration of surface treatment performance such as It is suppressed. Further, from the viewpoint of suppressing deposits on the inner wall of the raw material fluid discharge unit 30 and suppressing the secondary fluid 22 from flowing to the substrate 18 side, etc., the etching fluid in the secondary fluid 22 supplied into the raw material fluid discharge unit 30 The flow rate of the etching fluid in the mixed state of the raw material fluid 32 and the subfluid 22 on the inner wall of the raw material fluid discharge unit 30 is equal to or higher than the concentration of the etching fluid at which the film formation speed obtained in advance is zero. It is preferable to set as follows.

  The surface treatment apparatus 1 of the present embodiment is suitable for a surface treatment apparatus for high-speed film formation in which the supply pressure of the raw material fluid is set to 0.9 atm or higher and the raw material fluid concentration is set to 1% or higher. In the surface treatment apparatus 1 of the present embodiment, deposition of deposits on the inner wall of the raw material fluid discharge unit 30 is suppressed even when the supply pressure of the raw material fluid is 0.9 atm or higher and the raw material fluid concentration is 1% or higher. And it is suppressed that the subfluid 22 flows into the board | substrate 18 side. The raw material fluid concentration in this specification is the concentration of the reaction gas in the reaction gas and the carrier gas.

  Moreover, since the surface treatment apparatus 1 of this embodiment can suppress the deposit of the deposit on the inner wall of the raw material fluid discharge part 30 and can suppress the deterioration of the surface treatment performance of the substrate, the maintenance time of the apparatus can be reduced. It is possible to significantly reduce the film forming operation rate of the apparatus and reduce the processing cost.

  Hereinafter, the flow rate of the raw material fluid 32 will be described.

  From the viewpoint of suppressing the raw material fluid 32 that has flowed to the raw material fluid discharge unit 30 from flowing back and mixing into the raw material fluid inflow portion 28, the raw material fluid is disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-29592. It is preferable to optimize the set flow rate of 32.

  In order to optimize the set flow rate of the raw material fluid 32, non-patent literature (Dr. Hermann Schlicting (Translated by Dr. JK Kestin); Boundary-Layer Theory; Seventh Edition; USA; 1979; p102-104), which is an extension of the Navier-Stokes equations (8) and equation (9), which is a boundary condition for equation (8).

  Here, the fluid velocity u in the radial direction of the rotating substrate 18, the fluid velocity v in the circumferential direction of the rotating substrate 18, the fluid velocity w and pressure in the axial direction perpendicular to the flat plate surface of the rotating substrate 18. p is dimensionless (F, G, H, P) by the dimensionless distance ζ of Equation (10), and the temperature T is dimensionless by Φ.

Also, λ is the thermal conductivity, c is the heat capacity, f is the ratio of the value at the specific local position of the raw material fluid 32 to the value at the time of inflow of the raw material fluid 32, and f _ρ is shows density ratio, f _lambda is the thermal conductivity ratio of input time and local, f _c is the heat capacity ratio of the input time and local, respectively. P _r is the Prandtl number, and is an amount represented by P _r = ν / {λ / (ρ × c _P )}, where the constant pressure specific heat is c _P. Further, the subscript ∞ indicates the inflow state of the raw material fluid 32, and the subscript w indicates the state on the surface of the substrate 18. T represents the temperature of the sample holder 12 and ω represents the angular velocity of the sample holder 12.

  And each speed distribution (F, G, H) by a pump effect is calculated | required using Formula (8)-(10). F is a velocity distribution with respect to ζ in the radial direction of the rotating substrate 18, G is a velocity distribution with respect to ζ in the circumferential direction of the rotating substrate 18, and H is a velocity with respect to ζ in the axial direction of the rotating substrate 18. Distribution.

  Next, in the calculated velocity distribution H, a value with dimensionless distance ζ = ∞, that is, z = ∞ is obtained, and this is calculated as an axial velocity w (∞). An appropriate flow rate is obtained by multiplying the axial velocity w (∞) by the area A of the surface perpendicular to the flow path.

  By supplying the raw material fluid 32 to the substrate 18 at the flow rate of the raw material fluid 32 determined as described above, the raw material exhaust fluid flowing to the raw material fluid discharge unit 30 is prevented from flowing back to the raw material fluid inflow portion 28. Thereby, it is further suppressed that the etching fluid flows into the raw material fluid inflow portion 28 together with the raw material exhaust fluid that flows backward, and adverse effects on the film forming speed and film forming distribution of the substrate 18 are suppressed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail more concretely, this invention is not limited to a following example.

(Example 1-1)
In the apparatus configuration of FIG. 1, the flow rate of the raw material fluid is set by the equations (8) to (10), the supply pressure of the raw material fluid (SiHCl ₃ + H ₂ ) is 0.9 atm, and the raw material fluid concentration (SiHCl ₃ concentration) is 3%, the total flow rate of the secondary fluid (HCl + H ₂ gas) is set to 25 SLM, the HCl concentration in the secondary fluid is set to 20%, the HCl gas flow rate in the secondary fluid is set to 5 SLM, and the HCl concentration distribution in the raw fluid discharge part 30 Was obtained by simulation calculation. FIG. 4A is a diagram showing the HCl concentration distribution in the raw material fluid discharge part of Example 1-1, and FIG. 4B is the mole fraction of the fluid in the raw material fluid discharge part at a distance from point A. FIG. The solid line is the mole fraction of SiHCl ₃ obtained by simulation, the alternate long and short dash line is the mole fraction of HCl at which the film formation rate is zero when the temperature condition is 1000 ° C., and the broken line is the mole fraction of HCl obtained by simulation. It is a fraction.

  The auxiliary fluid is arranged perpendicularly or substantially perpendicular to the flow direction of the raw material fluid flowing through the raw material fluid inflow portion 28, and the auxiliary fluid discharged from the auxiliary fluid introduction portion 22 flows along the inner wall of the raw material fluid discharge portion 30 under the aforementioned flow rate condition. By flowing, as shown in FIG. 4A, the subfluid was prevented from flowing back to the substrate 18 side. Further, as shown in FIG. 4B, the molar fraction of HCl obtained by the simulation shows a higher value than the molar fraction of HCl at which the film formation rate becomes zero. It can be said that the accumulation of the deposits inside was suppressed.

(Comparative Examples 1-1 and 2-1)
In Comparative Example 1-1, the subfluid introduction part is provided on the sample holder 12, and the subfluid discharged from the subfluid introduction part is caused to flow from the lower side to the upper side in the vertical direction (subfluid (HCl + H ₂ gas)). ) Is set to 10 SLM, the HCl concentration in the secondary fluid is set to 50%, and the HCl gas flow rate in the secondary fluid is set to 5 SLM. The HCl concentration distribution was determined by simulation calculation. In Comparative Example 2-1, the subfluid introduction section is provided in the raw material fluid discharge section 30, and the subfluid discharged from the subfluid introduction section is caused to flow from the upper side to the lower side in the vertical direction (HCl + H ₂ The material fluid discharge section 30 is the same as in Example 1-1 except that the total gas flow rate is 10 SLM, the HCl concentration in the secondary fluid is 10%, and the HCl gas flow rate in the secondary fluid is 1 SLM. The HCl concentration distribution in was obtained by simulation calculation. FIG. 5A is a diagram showing the HCl concentration distribution in the raw material fluid discharge part of Comparative Example 1-1, and FIG. 5B is the HCl concentration distribution in the raw material fluid discharge part of Comparative Example 2-1. FIG.

  In Comparative Example 1-1 in which the subfluid discharged from the subfluid introduction portion provided on the sample holder 12 is flowed upward from the lower side in the vertical direction, the total flow rate of the subfluid is set to be lower than that in Example 1-1. Even though (the flow rate of HCl gas in the secondary fluid is the same as in Example 1), the secondary fluid was transported downstream with the raw material fluid, but it collided with the outer wall of the reaction vessel and flowed back to the substrate 18. . Further, in Comparative Example 2-1, in which the subfluid discharged from the subfluid introduction section provided in the raw material fluid discharge section 30 is flowed downward from the upper side in the vertical direction, the total flow rate of the subfluid and the HCl gas in the subfluid It was found that even when the flow rate was lower than that of Example 1-1, the secondary fluid diffused and reached the substrate 18. Further, neither Comparative Example 1-1 nor Comparative Example 2-1 was able to suppress the accumulation of deposits in the raw material fluid discharge part 30 as compared with Example 1-1.

  FIG. 6 is a diagram showing simulation results of the Si film formation rate on the substrates of Example 1-1 and Comparative Examples 1-1 and 2-1. As shown in FIG. 6, in Example 1-1 in which the back flow of the secondary fluid to the substrate 18 side was suppressed, the Si film formation rate on the substrate 18 was almost uniform from the center of the substrate 18 to the outer edge. That is, in Example 1-1, it turned out that the fall of surface treatment performance, such as a fall of the film-forming speed | rate and the in-plane uniformity of film-forming, can be suppressed. On the other hand, in Comparative Examples 1-1 and 2-1, in which the subfluid diffused toward the substrate 18 side, the Si film formation rate on the substrate 18 decreased as it moved from the center of the substrate 18 toward the outer edge. That is, in Comparative Examples 1-1 and 2-1, it was found that a decrease in film formation rate and a decrease in surface treatment performance such as in-plane uniformity of film formation cannot be suppressed.

(Examples 1-2 to 1-4)
In Example 1-2, the total flow rate of the secondary fluid (HCl + H ₂ gas) is set to 10 SLM, the HCl concentration in the secondary fluid is set to 20%, and the HCl gas flow rate in the secondary fluid is set to 2 SLM. In Example 1-3, the total flow rate of the secondary fluid (HCl + H ₂ gas) is 50 SLM, the HCl concentration in the secondary fluid is 10%, and the HCl gas flow rate in the secondary fluid is Except for setting to 5 SLM, the conditions are the same as in Example 1-1. In Example 1-4, the total flow rate of the secondary fluid (HCl + H ₂ gas) is 100 SLM, the HCl concentration in the secondary fluid is 10%, Except for setting the HCl gas flow rate in the secondary fluid to 10 SLM, the conditions are the same as in Example 1-1, and the HCl concentration distribution in the raw material fluid discharge unit 30 in each example is the same as in Example 1-1. Calculated by simulation calculation, raw material fluid To evaluate the presence or absence of the deposition of sediments in the output section 30. Further, similarly to Example 1-1, a simulation of the Si film formation rate on the substrate in each example was performed, and the in-plane uniformity of the film formation was evaluated. The subfluid flow rate conditions of Examples 1-1 to 1-4 are summarized in Table 1.

  As a result of simulation calculation of the HCl concentration distribution in the raw material fluid discharge unit 30 in each example, deposition of deposits in the raw material fluid discharge unit 30 was suppressed in any of the examples. In addition, as a result of performing a simulation of the Si film formation rate on the substrate in each example, it was confirmed that a decrease in the in-plane uniformity of the film formation was suppressed in any of the examples.

(Comparative Examples 1-2 to 1-3)
Comparative Example 1-2 is Comparative Example 1 except that the total flow rate of the secondary fluid (HCl + H ₂ gas) is 10 SLM, the HCl concentration in the secondary fluid is 10%, and the HCl gas flow rate in the secondary fluid is 1 SLM. −1, and in Comparative Example 1-3, the total flow rate of the secondary fluid (HCl + H ₂ gas) is 25 SLM, the HCl concentration in the secondary fluid is 20%, and the HCl gas flow rate in the secondary fluid is Except for setting to 5 SLM, the conditions are the same as in Comparative Example 1-1, and the HCl concentration distribution in the raw material fluid discharge unit 30 of Comparative Examples 1-2 to 1-3 is obtained by simulation calculation. The presence or absence of sediment was evaluated. In addition, similarly to Comparative Example 1-1, a simulation of the Si film formation rate on the substrate in Comparative Examples 1-2 to 1-3 was performed to evaluate the in-plane uniformity of film formation. The flow rate conditions of the subfluids of Comparative Examples 1-1 to 1-3 are summarized in Table 2.

  As a result of simulation calculation of the HCl concentration distribution in the raw material fluid discharge part 30 of Comparative Examples 1-2 to 1-3, Comparative Example 1-2 is similar to the above-described Comparative Example 1-1 in the raw material fluid discharge part 30. However, Comparative Example 1-3 was able to suppress the deposition of the deposit. Further, as a result of the simulation of the Si film formation rate on the substrate in Comparative Examples 1-2 to 1-3, Comparative Example 1-2 was different from Comparative Example 1-1 described above in that the film formation was uniform in the plane. Although the fall of property was suppressed, Comparative Example 1-3 was not able to suppress the fall of the in-plane uniformity of film-forming.

(Comparative Examples 2-2 to 2-4)
In Comparative Example 2-2, except that the total flow rate of the secondary fluid (HCl + H ₂ gas) is set to 10 SLM, the HCl concentration in the secondary fluid is set to 3%, and the HCl gas flow rate in the secondary fluid is set to 0.3 SLM. The conditions were the same as in Example 2-1, and in Comparative Example 2-3, the total flow rate of the secondary fluid (HCl + H ₂ gas) was 10 SLM, the HCl concentration in the secondary fluid was 30%, and the HCl gas in the secondary fluid The conditions are the same as in Comparative Example 2-1, except that the flow rate is set to 3 SLM. In Comparative Example 2-4, the total flow rate of the secondary fluid (HCl + H ₂ gas) is 30 SLM, and the HCl concentration in the secondary fluid 10% and the HCl gas flow rate in the secondary fluid is set to 3 SLM, and the conditions are the same as in Comparative Example 2-1, and the HCl concentration distribution in the raw material fluid discharge section 30 of Comparative Examples 2-2 to 2-4 is , Obtained by simulation calculation, in the raw material fluid discharge unit 30 To evaluate the presence or absence of the deposition of sediments. Similarly to Comparative Example 2-1, a simulation of the Si film formation rate on the substrate in Comparative Examples 2-2 to 2-4 was performed to evaluate the in-plane uniformity of film formation. The flow rate conditions of the subfluids of Comparative Examples 2-1 to 2-4 are summarized in Table 3.

  As a result of obtaining the HCl concentration distribution in the raw material fluid discharge part 30 of Comparative Examples 2-2 to 2-4 by simulation calculation, Comparative Example 2-2 is similar to Comparative Example 2-1, in the raw material fluid discharge part 30. However, in Comparative Examples 2-3 and 2-4, the deposition of the deposit in the raw material fluid discharge unit 30 was suppressed. In addition, as a result of the simulation of the Si film formation rate on the substrate in Comparative Examples 2-2 to 2-4, in Comparative Examples 2-2 to 2-4, as in Comparative Example 2-1, film formation was performed. A decrease in in-plane uniformity could not be suppressed.

  DESCRIPTION OF SYMBOLS 1 Surface treatment apparatus, 10 Reaction container, 12 Sample holder, 14 Partition, 16 Reaction gas supply apparatus, 18 Substrate, 20 Discharge processing apparatus, 22 Subfluid, 24 Rotating part, 26 Subfluid introduction part, 28 Cylindrical part or Raw material fluid inflow section, 30 Raw material fluid discharge section, 32 Raw material fluid, 34 Sub-fluid supply device.

Claims (4)

A reaction vessel, a sample holder provided inside the reaction vessel and holding and rotating a substrate as an object to be surface-treated; and provided above the sample holder in the reaction vessel, A raw material fluid inflow portion for supplying a raw material fluid, and a raw material provided on a side of the sample holder in the reaction vessel and discharging a raw material exhaust fluid after the raw material fluid has surface-treated the substrate A fluid discharge section, an introduction section for introducing a sub-fluid containing an etching fluid into the source fluid discharge section in the reaction vessel, and the source fluid is subjected to surface treatment on the substrate, A supply means for supplying to the introduction section,
The raw material fluid discharge part is a flow path that extends from the lower end of the raw material fluid inflow part toward the downstream side of the raw material fluid so as to surround a lateral outer periphery of the sample holder.
The introduction part is provided in the raw material fluid discharge part, and is perpendicular or substantially perpendicular to the flow direction of the raw material fluid flowing through the raw material fluid inflow part so that the sub-fluid flows along the inner wall of the raw material fluid discharge part. A surface treatment apparatus arranged vertically.   The flow rate of the etching fluid in the subfluid supplied by the supply means is determined in advance as the concentration of the etching fluid in a mixed state of the raw material fluid and the subfluid on the inner wall of the discharge portion. The surface treatment apparatus according to claim 1, wherein the surface treatment apparatus is set so as to be equal to or higher than an etching fluid concentration at which a film formation rate becomes zero.   The surface treatment apparatus according to claim 1 or 2, wherein the pressure of the raw material fluid flowing through the raw material fluid inflow portion is 0.9 atm or more.   The surface treatment apparatus according to claim 1, wherein the concentration of the raw material fluid flowing through the raw material fluid inflow portion is 1% or more.