JP2013163846A - Film deposition apparatus and film deposition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition apparatus and a film deposition method by which a substrate atmosphere is controlled to be constant, and a homogeneous film can be suitably formed on a substrate.SOLUTION: A chamber 17 has a double structure including an inner chamber 67 and an outer chamber 71. The temperature in the inner chamber 67 is controlled by supplying a fluid for temperature control to a second internal space 73 between the inner chamber 67 and the outer chamber 71, a supercritical fluid including a film material is supplied into the inner chamber 67, and further a substrate 1 is heated by a heater 83 to form a film on the substrate 1 thereby. Namely, the substrate atmosphere in the inner chamber 67 can be easily maintained constant by making the fluid for temperature control flow into the second internal space 73. In this way, a homogeneous film can be formed on the substrate 1. Also, the heating of the outer chamber 71 by the heater 83 can be prevented by making the fluid for temperature control flow into the second internal space 73.

Description

  The present invention relates to a film forming apparatus and a film forming method for performing supercritical film formation on a surface of a substrate in a chamber.

  Conventionally, for example, in supercritical film formation in which a film is formed on a substrate using a material in a supercritical fluid, an external device is provided in a chamber having a heating device (heater) for heating the substrate and a mechanism for holding pressure. It was performed by supplying a supercritical fluid.

  In this supercritical film formation, film formation is generally performed at a substrate temperature higher than the fluid temperature. This is because the film material in the supercritical fluid is deposited on the substrate surface at a predetermined substrate temperature higher than the fluid temperature.

  However, not only the substrate but also the fluid in the chamber is heated by the above-described heater for heating the substrate, and the chamber wall surface is heated directly from the heater or through the fluid, so that the substrate atmosphere (that is, the temperature around the substrate). And the state of fluid flow) are difficult to keep constant.

In other words, when the substrate temperature is uneven or the fluid flow on the substrate surface is disturbed, it is difficult to form a good quality film (film that has grown uniformly in the plane direction or thickness direction) on the substrate. When a substrate is heated by a heater, the heat of the heater is transmitted not only to the substrate but also to the fluid and the chamber, and conversely, the heat transmitted to them affects the fluid itself and the substrate, and the substrate atmosphere is kept constant due to the influence. In addition, it is not easy to keep the chamber at high pressure. In general, the chamber that holds the pressure for high pressure has a large heat capacity, so the temperature controllability is poor, and this is also a factor that makes it difficult to keep the substrate atmosphere constant. It was.

  In other words, once the temperature of the chamber rises, the fluid and the substrate receive a lot of heat from the chamber. For example, the reaction of deposition of the film material in the fluid may start, and a homogeneous film may be formed on the substrate. There was a problem that became difficult.

  Furthermore, convection may occur inside the chamber due to the temperature difference between the substrate and the fluid, and turbulence may occur due to the fluid supply speed, convection speed, etc. This also makes the substrate atmosphere difficult to be constant. It was a factor.

  In order to solve this problem, the following Patent Document 1 discloses a technique for improving the thermal responsiveness and controlling the atmosphere in the chamber by providing a thermal shield layer in the chamber.

JP 2007-162081 A

  In the technique of Patent Document 1 described above, a thermal shield layer having a high thermal conductivity is provided on the wall surface of the chamber to increase the thermal response of the chamber wall surface, thereby controlling the atmosphere. Sex seems to improve.

  However, since the thermal shield layer is in contact with the chamber wall surface, the temperature of the chamber wall surface is transmitted to the fluid and the substrate through the thermal shield layer, so that there is little effect of atmosphere control to keep the substrate atmosphere constant. There was a problem.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a film forming apparatus and a film forming method capable of suitably forming a homogeneous film on a substrate by controlling the substrate atmosphere to be constant. There is to do.

  (1) The invention of claim 1 is a film forming apparatus for forming a film on the substrate by supplying a supercritical fluid containing a film material into a chamber in which the substrate is disposed. A dual structure having an inner chamber in which the substrate is disposed and an outer chamber for accommodating the inner chamber, and controlling the temperature of the inner chamber in a space between the inner chamber and the outer chamber. Temperature control fluid supply means for supplying a temperature control fluid, supercritical fluid supply means for supplying a supercritical fluid containing the film material in the inner chamber, and heating for heating the substrate in the inner chamber Means.

  In the film forming apparatus of the present invention, the chamber has a double structure having an inner chamber and an outer chamber. By supplying a temperature control fluid to the space between the inner chamber and the outer chamber, the inner chamber The internal temperature is controlled, a supercritical fluid containing a film material is supplied into the internal chamber, and the substrate is heated by heating means, thereby forming a film on the substrate.

  In other words, in the present invention, the temperature of the wall surface of the inner chamber can be easily controlled when a supercritical film is formed on the substrate by flowing a temperature control fluid in the space between the inner chamber and the outer chamber. it can. Therefore, the substrate atmosphere in the inner chamber (and hence the substrate surface temperature) can be easily kept constant, so that a homogeneous film can be formed on the substrate.

  In general, the outer chamber has a large heat capacity and it is difficult to control the temperature. However, in the present invention, by flowing a temperature control fluid in the space between the inner chamber and the outer chamber, the outer chamber having a large heat capacity ( It is possible to suppress heating (by the heating means), and the substrate atmosphere can be made constant from this point as well.

Here, the supercritical fluid is a state of a substance placed at a temperature and pressure above the critical point (the same applies hereinafter).
Further, the temperature control fluid may be a gas, a liquid, or a supercritical fluid.

(2) The invention of claim 2 is characterized in that the supercritical fluid containing the film material is a fluid in which one or a plurality of precursors which are raw materials of the film material are dissolved.
The present invention exemplifies a supercritical fluid containing a membrane material. Here, the precursor is a substance that becomes a film material by reaction, as exemplified in Table 1 below.

(3) The invention of claim 3 is characterized in that the condition of the Reynolds number (Ne) <2300 is satisfied in the flow path of the installation location of the substrate in the inner chamber.
In the present invention, the flow path at the location of the substrate in the inner chamber (that is, the flow path of the supercritical fluid flowing on the substrate) satisfies the condition of Reynolds number (Ne) <2300, and therefore passes around the substrate. The fluid is laminar. By using a laminar flow of a steady flow, the temperature distribution is also steady, and the substrate atmosphere in the inner chamber can be easily kept constant, so that a more uniform film can be formed on the substrate.

  (4) In the invention of claim 4, the cross-sectional shape perpendicular to the flow direction of the supercritical fluid in the inner chamber is constant in the flow path of the installation location of the substrate in the inner chamber.

  In the present invention, since the cross-sectional shape perpendicular to the flow direction of the supercritical fluid (the flow path) is constant, the fluid passing around the substrate is made to have a stable flow such as a plug flow (with less turbulence). Is possible. Therefore, since the substrate atmosphere in the inner chamber can be easily maintained constant, a more uniform film can be formed on the substrate.

  (5) In the invention of claim 5, the supercritical fluid supplied into the inner chamber is set so that the flow path of the supercritical fluid expands in the width direction of the substrate before reaching the substrate. Has a diffusion mechanism.

  In the present invention, the supercritical fluid is supplied by the diffusion mechanism so as to spread in the width direction of the substrate (the plane direction in which the plate spreads and the direction perpendicular to the flow direction), so the direction of the flow velocity vector on the substrate surface Can be aligned. Therefore, the substrate atmosphere (particularly the substrate atmosphere in the width direction) in the inner chamber can be easily kept constant, so that a more uniform film can be formed on the substrate.

  (6) The invention according to claim 6 is characterized in that the heating means is provided at a place where the substrate is installed, and a preheating means for heating the supercritical fluid is provided upstream of the substrate.

  In the present invention, since the preheating means is provided upstream from the substrate, the supercritical fluid can be heated in advance before the supercritical fluid reaches the substrate. As a result, when the supercritical fluid flows around the substrate, the supercritical fluid can be set to an appropriate temperature for film formation.

  That is, since the supercritical fluid can be heated to an appropriate temperature in advance by the preheating means, the temperature gradient of the fluid on the substrate surface can be reduced. Therefore, the temperature on the substrate surface can be easily made constant.

(7) The invention of claim 7 is characterized in that a plurality of the heating means are arranged along the flow direction of the supercritical fluid, and the temperature of each heating means can be independently controlled.
Since the supercritical fluid flows from the upstream side to the downstream side of the substrate, when the heating means is single, the supercritical fluid flowing on the substrate has a temperature gradient along the flow, and the temperature on the downstream side becomes higher. .

  In contrast, the present invention includes a plurality of heating means (independently temperature-controllable) along the flow direction of the supercritical fluid, so that the upstream temperature is increased and the downstream temperature is decreased. By controlling the heating, the temperature of the substrate surface can be set constant. Thereby, a more uniform film can be formed on the substrate.

(8) The invention according to claim 8 is characterized in that the inner chamber has a smaller heat capacity than the outer chamber.
In the present invention, since the heat capacity of the inner chamber is smaller than the heat capacity of the outer chamber, the temperature of the inner chamber can be easily adjusted by the temperature control fluid (as compared with the case of controlling the temperature of the outer chamber).

(9) The invention of claim 9 is characterized in that the temperature of the temperature control fluid is the same temperature as the temperature of the supercritical fluid or a temperature lower than the temperature of the supercritical fluid.
In the present invention, by making the temperature of the temperature control fluid the same as the temperature of the supercritical fluid, it is possible to stabilize the temperature by suppressing the fluctuation of the temperature of the supercritical fluid. Further, by setting the temperature of the temperature control fluid to a temperature lower than the temperature of the supercritical fluid, even when the temperature of the supercritical fluid rises excessively due to heating from the heating means, the temperature rise can be suppressed.

Thereby, since the substrate atmosphere (particularly temperature) can be kept constant, a homogeneous film can be formed on the substrate.
(10) The invention of claim 10 is characterized by having a pressure control mechanism for controlling the pressure in the inner chamber and the pressure in the space between the inner chamber and the outer chamber.

  In the present invention, since the pressure control mechanism for controlling the pressure in the inner chamber and the pressure in the space between the inner chamber and the outer chamber is provided, for example, by controlling both pressures to be the same pressure, For example, the inner chamber can be prevented from being damaged due to the difference between the two pressures.

  (11) In the invention of claim 11, in the film forming method for forming a film on the substrate by supplying a supercritical fluid containing a film material into the chamber in which the substrate is disposed, A dual structure having an inner chamber in which the substrate is disposed and an outer chamber for accommodating the inner chamber, and a temperature for controlling the temperature of the inner chamber in a space between the inner chamber and the outer chamber. A control fluid is supplied, a supercritical fluid containing the film material is supplied to the substrate in the inner chamber, and the substrate in the inner chamber is heated to form a film on the substrate. It is characterized by performing.

The present invention has the same effects as those of the first aspect of the invention.
(12) The invention of claim 12 is characterized in that the supercritical fluid containing the film material is a fluid in which one or a plurality of precursors which are raw materials of the film material are dissolved.

The present invention exemplifies a supercritical fluid containing a membrane material.
(13) The invention of claim 13 is characterized in that the condition of the Reynolds number (Ne) <2300 is satisfied in the flow path of the installation location of the substrate in the inner chamber.

The present invention has the same effect as that of the third aspect of the invention.
(14) The invention of claim 14 is characterized in that the inner chamber is cooled by the temperature control fluid.

  In the present invention, by cooling the inner chamber with the temperature control fluid, even when the temperature of the supercritical fluid in the inner chamber rises excessively due to heating from the heating means, the temperature rise can be suppressed.

Thereby, since the substrate atmosphere (particularly temperature) can be kept constant, a more uniform film can be formed on the substrate.
In addition, each structure in this invention is demonstrated below.

-As a material of the said outer chamber and an inner chamber, various metals, such as stainless steel, can be used, for example.
-As the substrate, a Si wafer, a glass wafer or the like can be adopted.

  -As a film | membrane (thin film) formed by the said film-forming, and the precursor, reducing agent, or oxidizing agent used for the film-forming, the thing of following Table 1 is mentioned.

Cu (tmhd) ₂ : C ₂₂ H ₄₀ O ₄ Cu
Ru (tmhd) ₃ : C ₃₃ H ₅₇ O ₆ Ru
Me ₂ PtCOD: C ₁₀ H ₁₈ Pt
TEOS: C ₈ H ₂₀ O ₄ Si
Ti (O-iPr) ₂ (tmhd) ₂ : C ₂₈ H ₅₂ O ₆ Ti
Mn (pmcp) ₂ : C ₂₀ H ₃₀ Mn

In Example 1, it is explanatory drawing which shows the thin film formed on the board | substrate. 1 is an explanatory view showing a film forming apparatus of Example 1. FIG. It is explanatory drawing which shows the state which looked at the internal structure of the chamber in Example 1 from the side surface side. (A) is explanatory drawing which shows the planar structure inside the inner chamber in Example 1, (b) is explanatory drawing which shows the planar structure inside the inner chamber of a modification, (c) is an inner chamber of another modification. It is explanatory drawing which shows the plane structure inside. It is explanatory drawing which shows the state which looked at the internal structure of the chamber in Example 2 from the side surface side. FIG. 6 is an explanatory view showing a film forming apparatus of Example 3. It is explanatory drawing which shows the state which looked at the internal structure of the chamber in Example 3 from the side surface side. 6 is an explanatory view showing a film forming apparatus of Example 4. FIG. It is explanatory drawing which shows the state which looked at the internal structure of the chamber in Example 4 from the side surface side. 10 is an explanatory view showing a film forming apparatus of Example 5. FIG. It is explanatory drawing which shows the state which looked at the internal structure of the chamber in Example 5 from the side surface side.

  Next, a film forming apparatus and a film forming method of the present invention will be described with reference to the drawings.

a) First, a film forming apparatus for carrying out the film forming method of this embodiment will be described.
As shown in FIG. 1, the film forming method of the present embodiment uses, for example, a supercritical film forming technique on a disc-like substrate 1 made of silicon (Si), for example, having a diameter of 200 mm, and made of, for example, SiO ₂ An oxide layer (thin film) 3 having a thickness of 800 nm is formed. In this film forming method, a film forming apparatus 11 shown in FIG. 2 is used.

  As shown in FIG. 2, the film forming apparatus 11 of this example has a first pipeline 13, a second pipeline 15, a chamber 17, a third pipeline 19, and a fourth pipeline 21 from the upstream side of the flow channel. And. The first pipeline 13 is connected to the fifth pipeline 23, the sixth pipeline 25, and the seventh pipeline 27, and the second pipeline 15 is connected to the eighth pipeline 29. . Further, a ninth pipeline 31 is disposed so as to connect the first pipeline 13 and the third pipeline 19.

  The first to ninth pipes 13, 15, 19 to 31 have first to ninth manual valves 33, 35, 37, 39, 41, 43, 45, 47 for manually opening and closing the pipes, respectively. 49 are arranged. Instead of the manual valves 33 to 49, a control valve that opens and closes by a control signal from the electronic control device may be used.

Hereinafter, each configuration will be described in detail.
The fifth pipe 23 is a pipe for supplying carbon dioxide gas (CO ₂ ), which becomes a supercritical fluid, to the first pipe 13, and the first container 51 that stores the carbon dioxide gas from the upstream side. A first pump 53 for supplying carbon dioxide gas to the first pipe line 13 and the fifth manual valve 41 are disposed.

The sixth pipeline 25 supplies an oxide raw material (precursor) for generating an oxide of the material constituting the thin film 3, that is, TEOS (Si (OC ₂ H ₅ ) ₄ ) to the first pipeline 13. A second container 55 for containing TEOS, a second pump 57 for supplying TEOS to the first pipe 13, and the sixth manual valve 43 from the upstream side. Yes.

The seventh conduit 27 is a conduit for supplying oxygen gas (O ₂ ), which is an oxidant, to the first conduit 13, and from the upstream side, a third container 59 that contains oxygen gas, and oxygen A third pump 61 for supplying gas to the first pipeline 13 and the seventh manual valve 45 are arranged.

The eighth conduit 29 is a conduit for supplying carbon dioxide gas (CO ₂ ), which is a temperature control fluid, to the second conduit 15, and is a fourth container that stores the carbon dioxide gas from the upstream side. 63, a fourth pump 65 for supplying carbon dioxide gas to the second pipeline 15, and the eighth manual valve 47 are arranged.

  The first pipe line 13 supplies carbon dioxide gas, TEOS, and oxygen gas (for supercritical fluid) supplied from the fifth to seventh pipe lines 23 to 27 via the first manual valve 33 later. It is a pipe line that supplies the inside of the inner chamber 67 (that is, the first inner space 69) that constitutes the chamber 17 described below.

  The second pipe line 15 passes carbon dioxide gas (for temperature control) supplied from the eighth pipe line 29 through the second manual valve 35 in the outer chamber 71 constituting the chamber 17 described in detail later. That is, it is a pipe line that supplies to the second internal space 73 surrounded by the inner chamber 67 and the outer chamber 71.

  The third pipe line 19 is a pipe line that discharges the gas discharged from the inner chamber 67 (first internal space 69) (exhaust gas after film formation) to the outside of the film forming apparatus 11, and from the upstream side, The third manual valve 37 and the first pressure regulating valve 75 are arranged. The first pressure adjustment valve 75 is an adjustment valve that controls the upstream pressure to be a predetermined value (that is, an adjustment valve that automatically opens when the predetermined pressure is reached).

  The fourth pipe line 21 is a pipe line that discharges the gas discharged from the outer chamber 71 (second inner space 73) (temperature control carbon dioxide gas) to the outside of the film forming apparatus 11, and is located upstream. Thus, the fourth manual valve 39 and the second pressure regulating valve 77 (similar to the first pressure regulating valve 75) are arranged.

  The ninth pipe 31 is a pipe that bypasses the inner chamber 67, and is between the branch point 27a of the seventh pipe 27 and the first manual valve 33, and the third manual valve 37 and the first pressure regulating valve. 75.

b) Next, the configuration of the chamber 17 which is a main part of the present embodiment will be described.
As shown in FIG. 3, the chamber 17 used in the present embodiment has a double structure including a rectangular parallelepiped inner chamber 67 and a rectangular parallelepiped outer chamber 71 configured to cover the outer periphery of the inner chamber 67. This is the chamber 17.

  Among these, the inner chamber 67 includes a box-shaped frame 79 constituting the outer periphery of the inner chamber 67 made of stainless steel, a plate-shaped heat insulating material 81 made of foamed plastic disposed at the bottom of the frame 79, and a heat insulating material. And a plate-shaped substrate heating mechanism (heater) 83 disposed on the upper surface of 81.

  The first internal space 69 is formed above the heater 83, and the substrate 1 is disposed on the heater 83 in the first internal space 69. In the inner chamber 67, the height of the first internal space 69 (the thickness in the vertical direction in FIG. 3) is constant.

  The outer chamber 71 is a box-shaped frame made of stainless steel, in which the inner chamber 67 is accommodated, and between the outer side of the inner chamber 67 and the inner side of the outer chamber 71. An internal space 73 is configured.

  It should be noted that the outer chamber 71, which has a pressure difference inside and outside the chamber and needs to maintain the internal pressure, has a thicker wall than the inner chamber 67 which has no pressure difference inside and outside the chamber and does not need to hold the pressure. Thus, the heat capacity of the inner chamber 67 is smaller than the heat capacity of the outer chamber 71.

  Further, in the chamber 17, the first pipe line 13 is connected so as to penetrate the outer chamber 71 and communicate with the first inner space 69 in the inner chamber 67, and the third pipe line 19 is connected to the outer chamber 71. And is connected to communicate with the first internal space 69 in the inner chamber 67. That is, the first pipeline 13 opens on the upstream side (left side in FIG. 3) of the first internal space 69, and the third pipeline 19 opens on the downstream side (right side in FIG. 3).

  In addition, the second pipeline 15 is connected to the upstream side of the second internal space 73 of the outer chamber 71, and the fourth pipeline 21 is connected to the downstream side of the second internal space 73. In FIG. 3, two second pipes 15 and four fourth pipes 21 are illustrated, but each is simplified to one in FIG. 2.

  Further, in this embodiment, as shown in FIG. 4A, the planar shape of the inner chamber 67 is provided with a rectangular heater 83 in the rectangular parallelepiped portion at the center and on the downstream side of the heater 83. A disc-shaped substrate 1 is arranged. Note that a portion of the heater 83 on the upstream side of the substrate 1 heats a supercritical fluid containing a precursor and an oxidant supplied from the first pipe 13 (hereinafter sometimes simply referred to as a supercritical fluid or the like). The preheating unit 85 is configured.

  Further, in order to diffuse and flow the supercritical fluid between the first pipe 13 and the heater 83 in the vertical direction (the width direction of the heater 83) in the figure, the right side of the figure has a large triangular shape. A diffusion mechanism 87 is provided. The thickness of the diffusion mechanism 87 (size in the paper surface direction) is constant.

Note that the downstream side of the heater 83 also has a substantially triangular structure (but left-right reversed) similar to the diffusion mechanism 87, and is connected to the third pipeline 21.
In particular, in this embodiment, the internal structure and the characteristics of the flowing fluid are set so that the supercritical fluid flowing in the first inner space 69 of the inner chamber 67 becomes a laminar flow (particularly plug flow).

  Specifically, as shown in FIG. 3, the upper surface and the lower surface of the first internal space 69 are parallel and the vertical dimension is constant. Further, as shown in FIG. Then, the dimension in the width direction (the vertical direction in the figure) of the first internal space 69 is constant.

Further, the fluid characteristics and the like are set so that the Reynolds number (Re = UL / γ) satisfies Re <2300. For example, U = 3.5 × 10 ⁻² [m / s], L = 2.0 × 10 ⁻² [m], and γ = 3.5 × 10 ⁻⁷ [m ² / s].

U: velocity of supercritical fluid in the inner chamber [m / s]
L: Height in the inner chamber [m]
γ: Kinematic viscosity of supercritical fluid [m ² / s]
c) Next, a film forming method performed using the film forming apparatus 11 will be described.

(1) As shown in FIG. 2, first, the substrate 1 is placed at a predetermined position on the heater 83 (see FIG. 4A) in the inner chamber 67.
(2) Next, the first, second, third, fourth, fifth, and eighth manual valves 33, 35, 37, 39, 41, and 47 are opened. The other manual valves are closed.

  (3) Next, the first and fourth pumps 53 and 65 are operated to supply carbon dioxide gas for the supercritical fluid into the inner chamber 67 (first inner space 69), and at the same time, carbon dioxide for temperature control. Gas is supplied into the outer chamber 71 (second inner space 73).

The flow rate of each fluid to be supplied is 100 cc / min in the liquid state. The temperature of each fluid when flowing into the chamber 17 is 50 ° C.
(4) At the same time, the entire film forming apparatus 11 is heated to 50 ° C. by a heater (not shown), and the heater 83 for heating the substrate is heated to 400 ° C. As a result, the pressure in the inner chamber 67 and the outer chamber 71 is increased to 12 MP. The pressure is adjusted by the first and second pressure regulating valves 75 and 77.

(5) Next, the sixth and seventh manual valves 43 and 45 are opened.
(6) Next, the second and third pumps 57 and 61 are operated to supply the film material precursor TEOS into the inner chamber 67. The flow rate of the fluid is 0.5 cc / min in the liquid state.

At the same time, oxygen gas as an oxidizing agent for the film material is supplied into the inner chamber 67. The flow rate of the fluid to be supplied is 3200 cc / min at room temperature and normal pressure.
At this time, the state of the carbon dioxide gas for the supercritical fluid supplied to the inner chamber 67 is a supercritical state exceeding the critical point (pressure 7.38 MPa, temperature 31.1 ° C.).

In this state, film formation is performed for 30 minutes.
(7) After the film formation is completed, the sixth and seventh manual valves 43 and 45 are closed, and the second and third pumps 57 and 61 are stopped to stop the supply of the precursor of the film material and the oxidizing agent, In this state, carbon dioxide gas for supercritical fluid is supplied into the inner chamber 67 and purged for 10 minutes.

(8) Then, the temperature and pressure are set to normal temperature and normal pressure, and the process is terminated.
By this film forming process, an SiO ₂ film having a thickness of 800 nm was formed on the substrate 1.
The reaction formula (1) for film formation is shown below.

Si (OC ₂ H ₅ ) ₄ → SiO ₂ + 4C ₂ H ₄ + 2H ₂ O (1)
d) As described above, in this embodiment, the chamber 17 has a double structure having the inner chamber 67 and the outer chamber 71. Then, by supplying a temperature control fluid to the second internal space 73 between the inner chamber 67 and the outer chamber 71, the temperature in the inner chamber 67 is controlled, and the inner chamber 67 contains a film material. A thin film 3 is formed on the substrate 1 by supplying a critical fluid and further heating the substrate 1 with a heater 83.

  That is, in this embodiment, when a supercritical film is formed on the substrate 1 by forming a double structure of the inner chamber 67 and the outer chamber 71 and flowing a temperature control fluid in the second internal space 73 between them. The substrate atmosphere in the inner chamber 67 can be easily kept constant. Thereby, a homogeneous thin film 3 can be formed on the substrate 1.

  In addition, by flowing a temperature control fluid through the second internal space 73, it is possible to prevent the outer chamber 71 having a large heat capacity and difficult to control the temperature from being heated by the heater 83, and also from this point, the substrate atmosphere is kept constant. can do.

  Furthermore, in this embodiment, the flow path at the location where the substrate 1 is installed in the inner chamber 67 satisfies the condition of Reynolds number (Ne) <2300, so the fluid passing around the substrate 1 is a laminar flow. Therefore, the substrate atmosphere in the inner chamber 67 can be easily maintained constant.

  In addition, in the present embodiment, since the cross-sectional shape perpendicular to the flow direction of the supercritical fluid in the inner chamber 67 is constant in the flow path at the place where the substrate 1 is installed in the inner chamber 67, The fluid passing through can be made into a steady flow like plug flow (with less turbulence). Therefore, the substrate atmosphere in the inner chamber 67 can be easily maintained constant.

  In this embodiment, since the supercritical fluid is supplied by the diffusion mechanism 87 so as to spread in the width direction of the substrate 1, the direction of the flow velocity vector on the substrate surface can be made uniform. Therefore, the substrate atmosphere in the inner chamber 67 can be easily maintained constant.

  Furthermore, in this embodiment, since the preheating unit 85 is provided on the upstream side of the substrate 1, the supercritical fluid can be heated in advance before the supercritical fluid reaches the substrate 1. Thereby, the temperature gradient of the substrate surface is reduced, and the temperature of the substrate surface can be easily made constant.

  In addition, in this embodiment, since the heat capacity of the inner chamber 67 is smaller than the heat capacity of the outer chamber 71, the temperature of the inner chamber 67 is adjusted by the temperature control fluid (as compared with the case of controlling the temperature of the outer chamber 71). Can be easily performed.

  In this embodiment, since the temperature of the temperature control fluid is the same as the temperature of the supercritical fluid, the temperature of the supercritical fluid (in the inner chamber 67) can be suppressed and stabilized. Thereby, since the substrate atmosphere (particularly temperature) can be kept constant, a more uniform thin film 3 can be formed on the substrate 1.

  By setting the temperature of the temperature control fluid to a temperature lower than that of the supercritical fluid, even if the temperature of the supercritical fluid rises excessively due to heating from the heater 83, the temperature rise can be suppressed.

  Further, in this embodiment, the first and second pressure adjustments for controlling the pressure of the first internal space 69 in the inner chamber 67 and the pressure of the second internal space 73 between the inner chamber 67 and the outer chamber 67. Since the valves 75 and 77 are provided, the pressure adjustment valves 75 and 77 are used to control the pressures of the internal spaces 69 and 73 to be the same pressure. Breakage can be prevented.

The preheating unit 85 can be omitted.
e) Moreover, the following structure is employable as a modification of a present Example.
For example, as shown in FIG. 4B, a first conduit 97 is disposed on the upstream side of the inner chamber 95 containing the heater 93 on which the substrate 91 is placed, and the first piping 97 A pipe 97a branched so as to spread in the width direction like the diffusion mechanism may be provided on the downstream side, and the supercritical fluid may be supplied in parallel to the heater 93 side from the pipe 97a.

This device also has the same effect as the diffusion mechanism.
Further, as shown in FIG. 4C, for example, a heater 109 on which a diffusion mechanism 103, a preheating unit 105, and a substrate 107 are placed is provided in the inner chamber 101, and the heater 109 is further connected to a supercritical fluid. A plurality of individual heaters may be formed along the flow direction, and the individual heaters may be independently temperature-controllable.

  In other words, since there are multiple individual heaters (independently temperature-controllable) along the flow direction of the supercritical fluid, heating control is performed so that the upstream temperature is increased and the downstream temperature is decreased. It can be performed. Therefore, since the substrate temperature can be easily set to be constant, a more uniform thin film can be formed on the substrate 107.

Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
The film forming apparatus of the present embodiment is different from the first embodiment because the internal configuration of the inner chamber is different.

  As shown in FIG. 5, the chamber 111 used in the film forming apparatus of this embodiment has a double structure of an inner chamber 113 and an outer chamber 115 as in the first embodiment. The flow path is the same as that in the first embodiment.

  In particular, in the present embodiment, a lower heat insulating material 119 and a lower heater 121 (having the same configuration as that of the first embodiment) are provided below the first inner space 117 in the center of FIG. A similar upper heat insulating material 123 and upper heater 125 are also provided above.

That is, the heaters 121 and 125 are provided above and below so as to sandwich the first internal space 117. Thereby, the temperature distribution in the vertical direction can be reduced.
For example, depending on the type of precursor, which is a film material, there is a type in which a uniform thin film can be easily formed on the substrate 127 (mounted on the lower heater 121) with a smaller temperature distribution in the vertical direction.

Therefore, in this embodiment, there is an advantage that a homogeneous thin film can be formed more suitably depending on the type of film material used.
In the present embodiment, the configuration of the modification (see FIGS. 4B and 4C) may be employed.

Next, the third embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
The film forming apparatus of the present example is different from Example 1 in the internal configuration of the inner chamber, and the flow path is slightly different accordingly.

a) First, the film forming apparatus of the present embodiment will be described with reference to FIG.
As shown in FIG. 6, the film forming apparatus 131 of this embodiment includes a first pipe 133, a second pipe 135, a chamber 137, and a third pipe 139 from the upstream side. In addition, a fourth pipeline 141, a fifth pipeline 143, and a sixth pipeline 145 are connected to the first pipeline 133, and a seventh pipeline 147 is connected to the second pipeline 135. . Further, an eighth pipe 149 is disposed so as to connect the first pipe 133 and the third pipe 139. In addition, first to eighth manual valves 151, 153, 155, 157, 159, 161, 163, and 165 are disposed in the first to eighth pipe lines 133, 135, and 139 to 149, respectively.

Among these, the fourth pipe 141 is provided with a first container 167 for storing carbon dioxide gas (for supercritical fluid), a first pump 169, and the fourth manual valve 157.
In the fifth pipe line 143, a second container 171 containing TEOS (which is a precursor), a second pump 173, and the fifth manual valve 159 are arranged.

The sixth pipe 145 is provided with a third container 175 for storing oxygen gas (which is an oxidant), a third pump 177, and the sixth manual valve 161.
A fourth container 179 that stores carbon dioxide gas (which is a temperature control fluid), a fourth pump 181, and the seventh manual valve 163 are disposed in the seventh conduit 147.

The first pipe 133 is a pipe that supplies the carbon dioxide gas (for supercritical fluid), TEOS, and oxygen gas into the inner chamber 183 of the chamber 137.
The second pipe 135 is a pipe that supplies the carbon dioxide gas (for temperature control) into the outer chamber 185 of the chamber 137.

The third manual valve 155 and the pressure regulating valve 187 are arranged in the third pipe line 139 from the upstream side.
b) Next, the structure of the chamber 137 will be described with reference to FIG.

As shown in FIG. 7, the chamber 137 has a double structure including an inner chamber 183 and an outer chamber 185.
Among these, the outer chamber 185 includes a box-shaped container 189 having an open top, and a lid 191 that covers the opening 189 a of the container 189. The container 189 and the lid 191 are integrally fixed in an airtight state by a fixing member (such as a bolt or a nut) and a sealing member (such as a packing) (not shown).

  The inner chamber 183 has a structure in which an inner space (first inner space) 193 is bent in the middle, and two layers of space (upper space 193a and lower space 193b) are overlapped.

  That is, the flat upper space 193a and the flat lower space 193b having a larger area in the plane direction are overlapped with each other, and the upper space 193a and the lower space 193b are connected to the left side in FIG. It is configured to communicate with each other by turning back at 193c. As in the first embodiment, a heat insulating material 195 and a heater 197 are arranged at the bottom of the lower space 193b.

  Further, a first pipe 133 is disposed through the lid 191 of the outer chamber 185 (supplied with a supercritical fluid or the like), and the first pipe 133 is the same as the upper space 193a of the inner chamber 183. Connected to the right end of the figure.

Further, a third pipe line 139 is disposed through the wall surface 189b on the downstream side of the container 189 of the outer chamber 185.
Further, a communication pipe 199 (having a smaller diameter than the third pipe line 139) is provided on the downstream side of the lower space 193b. The communication pipe 199 is coaxially arranged with a slight gap from the third pipe 139, and an opening 199a on the downstream side of the communication pipe 199 opens toward the opening 139a of the third pipe 139. ing.

The second pipe 135 (to which the temperature control fluid is supplied) is disposed so as to penetrate the upstream wall surface 189c of the container 189 of the outer chamber 185.
c) In this embodiment, the supercritical fluid or the like is supplied to the upper space 193a of the inner chamber 183, and the flow path is changed in the reverse direction via the communication portion 193c to flow through the lower space 193b. Thereby, since the flow velocity vectors in the lower space 193b can be made uniform, the substrate atmosphere can be made constant, and thus a homogeneous thin film can be easily formed on the substrate 201.

  In this embodiment, since the inner chamber 183 can be connected to the lid 191 side of the outer chamber 185, the chamber 137 can be easily opened and closed. Moreover, since the existing pressure vessel can be utilized, there exists an advantage that the freedom degree at the time of a design etc. is high.

  In the present embodiment, the supercritical fluid or the like serving as exhaust and the temperature control fluid merge on the downstream side in the inner chamber 183, but they merge and are discharged from the third conduit 139. There is no problem in film formation in the inner chamber 183.

Next, the fourth embodiment will be described, but the description of the same contents as the first embodiment will be omitted.
The film forming apparatus of this example is different from that of Example 1 in the flow path.
a) First, the film forming apparatus of the present embodiment will be described with reference to FIG.

  As shown in FIG. 8, the film forming apparatus 211 of this embodiment includes a first pipe 213, a chamber 215, and a second pipe 217 from the upstream side of the flow path. In addition, a third pipeline 219, a fourth pipeline 221 and a fifth pipeline 223 are connected to the first pipeline 213. Furthermore, a sixth pipeline 225 is disposed so as to connect the first pipeline 213 and the second pipeline 217. A seventh pipe 227 is connected to the first pipe as a branch pipe. In addition, first to eighth manual valves 229, 231, 233, 235, 237, and 239 are disposed in the first to sixth pipelines 213 to 225, respectively.

Among these, the third pipe 219 is provided with a first container 241 for storing carbon dioxide gas (for supercritical fluid), a first pump 243, and the third manual valve 233.
In the fourth conduit 221, a second container 245 for accommodating TEOS (which is a precursor), a second pump 247, and the fourth manual valve 235 are arranged.

A third container 249 that stores oxygen gas (which is an oxidant), a third pump 251, and the fifth manual valve 237 are disposed in the fifth pipe 223.
Note that the fourth pipe 221 and the fifth pipe 223 merge at the merge channel 224 before the first pipeline 213, and the merge channel 224 is connected to the first pipeline 213.

The first pipe 213 is a pipe that supplies the carbon dioxide gas, TEOS, and oxygen gas into the inner chamber 253 of the chamber 217.
The seventh conduit 227 is a conduit that supplies the carbon dioxide gas into the outer chamber 255 of the chamber 215.

The second manual valve 231 and the pressure regulating valve 257 are arranged in the second pipe line 139 from the upstream side.
b) Next, the structure of the chamber 215 will be described with reference to FIG.

As shown in FIG. 9, the chamber 215 has a double structure including an inner chamber 253 and an outer chamber 255.
Among these, in the inner chamber 253, the heat insulating material 261 and the heater 263 are disposed at the bottom of the first internal space 259, and the substrate 265 is disposed on the heater 263, as in the first embodiment.

The outer chamber 255 is connected to the seventh pipe 227 on the upstream side and to the second pipe 217 on the downstream side.
In particular, in the present embodiment, the first pipe 213 is coaxially arranged inside the seventh pipe 227 (that is, a double pipe), and the combined flow path 224 is connected to the first pipe 213. The first conduit 213 communicates with the first internal space 259 of the inner chamber 253, and the seventh conduit 227 communicates with the second internal space 267 of the outer chamber 255.

  In addition, a communication path 269 is connected to the downstream side of the first internal space 259, and the downstream side of the communication path 269 is coaxially disposed inside the second pipe 217 (that is, a double pipe and To do).

  c) In this embodiment, the supercritical fluid is supplied with the precursor and the oxidant and supplied to the first inner space 259 of the inner chamber 253, and the same supercritical fluid is used for temperature control as the outer chamber. 255 is supplied to the second internal space 267.

  Then, the supercritical fluid or the like discharged from the second internal space 267 of the inner chamber 253 is discharged from the communication pipe 269 into the second pipe 217 and from the second internal space 267 of the outer chamber 255 (temperature control). Supercritical fluid is discharged to the same second conduit 217. That is, both fluids merge and are discharged to the second pipe 217.

  That is, in this embodiment, the same supercritical fluid is branched and supplied to the first internal space 259 and the second internal space 267, and is discharged from the first internal space 159 and the second internal space 267. The fluid and the like merge at the second pipe 217 and are discharged.

Thereby, the pressure in the inner chamber 253 and the pressure in the outer chamber 255 can be easily maintained at the same pressure.
Also in this embodiment, the film material discharged from the first internal space 259 may flow backward and reach the second internal space 267, but there is no particular problem because the amount is small.

Next, although Example 5 is demonstrated, description of the content similar to the said Example 1 is abbreviate | omitted.
The film forming apparatus of the present embodiment is different from the first embodiment in the configuration of the flow path and pressure adjustment.
a) First, the film forming apparatus of the present embodiment will be described with reference to FIG.

  As shown in FIG. 10, the film forming apparatus 271 of this example includes a first conduit 273, a second conduit 275, a chamber 277, a third conduit 279, and a fourth conduit 281 from the upstream side. ing. In addition, a fifth pipe 283, a sixth pipe 285, a seventh pipe 287, and an eighth pipe 289 are connected to the first pipe 273. Furthermore, a ninth pipe 291 is arranged so as to connect the first pipe 273 and the third pipe 217. Note that first to ninth manual valves 293, 295, 297, 299, 301, 303, 305, 307, and 309 are disposed in the first to ninth pipelines 273, 275, and 279 to 291, respectively.

Among these, the fifth pipe 219 is provided with a first container 311 for storing carbon dioxide gas (for supercritical fluid), a first pump 313, and the fifth manual valve 301.
In the sixth pipe line 285, a second container 365 for accommodating TEOS (which is a precursor), a second pump 367, and the sixth manual valve 303 are arranged.

In the seventh pipe line 287, a third container 369 for storing oxygen gas (which is an oxidant), a third pump 371, and the seventh manual valve 305 are arranged.
A fourth container 373 that stores liquid water (for temperature control), a fourth pump 375, and the eighth manual valve 307 are disposed in the eighth pipe 219.

The first conduit 273 is a conduit that supplies the carbon dioxide gas (for supercritical fluid), TEOS, and oxygen gas into the inner chamber 377 of the chamber 277.
The second pipe 275 is a pipe that supplies the water (for temperature control) into the outer chamber 379 of the chamber 277.

The third conduit 279 is a conduit for discharging supercritical fluid or the like from the inside of the inner chamber 377, and the third manual valve 297 and the first pressure regulating valve 381 are arranged from the upstream side.
The fourth pipe line 281 is a pipe line for discharging the temperature control fluid from the inside of the outer chamber 379, and the fourth manual valve 299 and the second pressure regulating valve 383 are arranged from the upstream side.

The first and second pressure regulating valves 381 and 383 are control valves whose opening degree is controlled by a control signal, as will be described later.
Further, the first communication line 279 and the fourth pressure control valve 381 and 383 are connected between the third and fourth manual valves 297 and 299 and the first and second pressure control valves 381 and 383 so as to connect the first communication line. A passage 385 and a second communication passage 387 are provided, and each of the first communication passage 385 and the second communication passage 387 is allowed to flow in the direction indicated by the arrow in FIG. A first check valve 389 and a second check valve 391 are arranged.

b) Next, the structure of the chamber 277 will be described with reference to FIG.
As shown in FIG. 11, the chamber 277 has a double structure including an inner chamber 377 and an outer chamber 379.

  Among these, in the inner chamber 377, as in the first embodiment, the heat insulating material 395 and the heater 397 are disposed at the bottom of the first internal space 393, and the substrate 399 is disposed on the heater 397. In addition, a first pipe 273 is connected to the upstream side of the first internal space 393, and a third pipe 279 is connected to the downstream side.

On the other hand, the second internal space 399 of the outer chamber 379 is connected to the second pipe 275 on the upstream side and to the fourth pipe 281 on the downstream side.
In particular, the present embodiment includes a first pressure sensor 401 that detects the pressure in the first internal space 393 and a second pressure sensor 403 that detects the pressure in the second internal space 399.

  c) In this embodiment, when supercritical film formation is performed, the first pressure adjustment is performed by an electronic control unit (not shown) based on the pressure in the first internal space 393 detected by the first pressure sensor 401. The valve open state of the valve 381 is controlled, and the electronic controller controls the valve open state of the second pressure regulating valve 383 based on the pressure in the second internal space 399 detected by the second pressure sensor 403. Yes.

That is, the pressure in the first internal space 393 and the pressure in the second internal space 399 are controlled to be the same. Thereby, damage to the apparatus due to both pressure differences can be prevented.
In addition, since the first check valve 389 and the second check valve 391 are disposed so as to connect the third pipe line 279 and the fourth pipe line 281 (the direction in which the flow is permitted is reversed) Even when an abrupt pressure change occurs, the high pressure is released to other pipes, so that the apparatus can be prevented from being damaged.

Needless to say, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the scope of the present invention.
For example, in each of the above embodiments, the film forming apparatus operated manually is described. For example, an electromagnetic control valve (open / close valve) is used instead of the manual valve, and the opening / closing timing and the degree of opening / closing of the electromagnetic control valve are determined. The thin film may be formed automatically under the control of an electronic control unit. The operation of the pump can also be controlled by an electronic control unit.

1, 91, 107, 201, 265, 399 ... substrate 3 ... oxide layer (thin film)
11, 131, 211, 271 ... film forming apparatus 17, 111, 137, 215, 277 ... chamber 67, 113, 183, 253, 377 ... inner chamber 69, 117, 193, 259, 393 ... first internal space 71, 115, 185, 255, 379 ... outer chamber 73, 267, 399 ... second inner space 83, 93, 109, 121, 125, 197, 263, 397 ... substrate heating mechanism (heater)
85, 105 ... Preheating unit 87, 103 ... Diffusion mechanism 75, 77, 187, 257, 381, 383 ... Pressure regulating valve

Claims (14)

In a film forming apparatus for supplying a supercritical fluid containing a film material into a chamber in which a substrate is disposed, and forming a film on the substrate,
The chamber includes a double structure having an inner chamber in which the substrate is disposed, and an outer chamber that houses the inner chamber,
Temperature control fluid supply means for supplying a temperature control fluid for controlling the temperature of the inner chamber to a space between the inner chamber and the outer chamber;
Supercritical fluid supply means for supplying a supercritical fluid containing the film material into the inner chamber;
Heating means for heating the substrate in the inner chamber;
A film forming apparatus comprising:   The film forming apparatus according to claim 1, wherein the supercritical fluid containing the film material is a fluid in which one or a plurality of precursors that are raw materials of the film material are dissolved.   3. The film forming apparatus according to claim 1, wherein a condition of a Reynolds number (Ne) <2300 is satisfied in a flow path of the installation location of the substrate in the inner chamber.   The cross-sectional shape perpendicular to the flow direction of the supercritical fluid in the inner chamber is constant in the flow path of the installation location of the substrate in the inner chamber. The film forming apparatus according to item.   The supercritical fluid supplied into the inner chamber has a diffusion mechanism that sets the flow path of the supercritical fluid in the width direction of the substrate before reaching the substrate. The film-forming apparatus of any one of Claims 1-4.   The said heating means is provided in the installation location of the said board | substrate, The preliminary heating means which heats the said supercritical fluid is provided in the upstream from the said board | substrate, The any one of Claims 1-5 characterized by the above-mentioned. Film forming equipment.   The heating means is arranged in plural along the flow direction of the supercritical fluid, and each heating means can be independently temperature controlled. The film-forming apparatus of description.   The film forming apparatus according to claim 1, wherein the inner chamber has a smaller heat capacity than the outer chamber.   The film formation according to any one of claims 1 to 8, wherein a temperature of the temperature control fluid is the same temperature as the temperature of the supercritical fluid or a temperature lower than the temperature of the supercritical fluid. apparatus.   The composition according to any one of claims 1 to 9, further comprising a pressure control mechanism that controls a pressure in the inner chamber and a pressure in a space between the inner chamber and the outer chamber. Membrane device. In a film forming method for forming a film on the substrate by supplying a supercritical fluid containing a film material into a chamber in which the substrate is disposed.
The chamber includes a double structure having an inner chamber in which the substrate is disposed, and an outer chamber that houses the inner chamber.
Supplying a temperature control fluid for controlling the temperature of the inner chamber to a space between the inner chamber and the outer chamber, and supplying a supercritical fluid containing the film material to the substrate in the inner chamber; and A film forming method comprising forming a film on the substrate by heating the substrate in the inner chamber.   The film forming method according to claim 11, wherein the supercritical fluid containing the film material is a fluid in which one or a plurality of precursors that are raw materials of the film material are dissolved.   13. The film forming method according to claim 11, wherein a condition of a Reynolds number (Ne) <2300 is satisfied in a flow path of the installation location of the substrate in the inner chamber.   The film forming method according to claim 11, wherein the inner chamber is cooled by the temperature control fluid.