JP2008294217A - Vapor phase growth device and vapor phase growth method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor phase growth device and a vapor phase growth method which can control the temperature distribution in the whole surface of a wafer to be uniform and can deposit a good crystal film with uniform thickness by supporting the wafer while making it float. <P>SOLUTION: The vapor growth device is provided with: a holder 103 which supports a wafer 102 while making the wafer 102 float by a bernoulli chuck in a chamber 101; a process gas supplying part 104 which supplies a process gas for depositing the crystal film in a surface of the wafer 102; and a gas exhausting part 105 which exhausts a gas containing the process gas in the chamber 101 after deposition out of the chamber 101. Thereby, the temperature distribution in the whole surface of a wafer can be controlled to be uniform. As a result, the uniformity of the distribution of the film thickness in the crystal film which is deposited in the surface of the wafer 102 can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vapor phase growth apparatus and a vapor phase growth method, and more particularly to gas supply to a substrate on which an epitaxial growth film is formed and support of the substrate in the epitaxial growth apparatus.

In the manufacture of a high-performance semiconductor element, an epitaxial growth technique capable of controlling the thickness of the deposited crystal film and the impurity concentration is indispensable for improving the performance of the semiconductor element.
In general, an atmospheric pressure chemical vapor deposition method is used for epitaxial growth in which a single crystal thin film is formed on a substrate such as a silicon wafer, and a low pressure chemical vapor deposition (LPCVD) method is used in some cases. The substrate is accommodated in a vapor deposition reactor, and the substrate is heated and rotated in a state where the vapor deposition reactor is maintained at a normal pressure (0.1 Mpa (760 Torr)) or a vacuum atmosphere of a predetermined degree of vacuum. However, a source gas in which a silicon source and a dopant such as a boron compound, a phosphorus compound, or an arsenic compound are mixed is supplied. Then, a thermal decomposition reaction or hydrogen reduction reaction of the source gas is performed on the surface of the heated substrate, and a crystalline film doped with boron (B), phosphorus (P), or arsenic (As) is formed on the substrate.

  Here, since the film thickness of the epitaxial growth film depends on the temperature of the substrate surface at the time of reaction, in order to obtain a crystal film with a uniform film thickness, it is required to control the heating of the substrate so as to have a uniform temperature distribution. It is done. Therefore, various measures have been taken to control the temperature distribution on the heated substrate surface.

FIG. 19 is a conceptual view showing a cross-sectional view of a vapor phase growth apparatus 500 that supports a conventional substrate 502 in direct contact with a holder 503.
The substrate 502 accommodated in the chamber 501 is placed with the back surface in contact with the holder 503. The holder 503 is attached to an upper portion of a rotating body 520 that is connected to a rotating mechanism (not shown) and can rotate. Further, a heater 506 for heating the substrate 502 is provided immediately below the substrate 502, and heats the substrate 502 from the back surface. A process gas supply unit 504 for supplying a process gas for forming a film on the substrate 502 into the chamber 501 is disposed in the upper part of the chamber 501, and an exhaust for exhausting the process gas after the film formation is provided in the lower part of the chamber 501. Part 505 is arranged.
The substrate 502 can be rotated accompanying the holder 503 rotated by the rotating body 520. Then, a process gas is supplied from the process gas supply unit 504 into the chamber 501 while being heated to a predetermined temperature by the heater 506, thereby forming a crystal film on the surface of the substrate 502.

  However, in this aspect, even if the substrate 502 is evenly heated by the heater 506, the substrate 502 and the holder 503 are in contact with each other. End up. For this reason, it is difficult to make the temperature distribution in the entire surface of the substrate 502 uniform only by controlling the output of the heater 506.

Here, although not directly related to the epitaxial growth technique, a technique for supporting a substrate or the like in a heat treatment chamber by a Bernoulli chuck is disclosed (Patent Document 1).
JP 2003-257882 A

  In the conventional vapor phase growth apparatus, heat is radiated from the substrate to the holder, and the temperature at the peripheral edge of the substrate tends to decrease. For this reason, an error occurs in the temperature distribution at the peripheral portion and the central portion of the substrate, and it has been difficult to control this uniformly. Therefore, there is a problem that it is difficult to control the film thickness of the crystal film to be formed constant.

In the conventional vapor phase growth apparatus, not only the substrate but also the holder is heated to the same temperature as the substrate, and a crystal film is formed on the surface of the holder. In the conventional mode of supporting the substrate in direct contact with the holder, the crystal film generated on the surface of the holder during repeated film formation becomes an obstacle, and the substrate is placed at a predetermined position. Or it cannot be transported. In order to prevent this, the holder must be periodically washed with hydrochloric acid (HCl) or the like. As a matter of course, since film formation cannot normally be performed while the holder is cleaned, the productivity of the apparatus is greatly reduced.
Thus, the conventional vapor phase growth apparatus also has a problem with productivity.

  The present invention has been made to overcome such problems, and by controlling the entire surface of the substrate to have a uniform temperature distribution, a high-quality crystal film having a uniform thickness can be formed on the substrate surface. In addition, a vapor phase growth apparatus and a vapor phase growth method that do not require maintenance or the like that affect productivity are provided.

The vapor phase growth apparatus of the present invention is
A chamber;
A holder for supporting the substrate in a floating state in the chamber;
A process gas supply unit that supplies a process gas for forming a crystal film on the substrate surface by vapor deposition into the chamber;
An exhaust section for exhausting the gas in the chamber containing the process gas after film formation to the outside of the chamber;
It is characterized by providing.

  With this configuration, since a space exists between the substrate and the holder, it is possible to eliminate unnecessary heat loss that has conventionally occurred at the portion where the substrate and the holder are in contact with each other. Therefore, it is possible to form a high-quality crystal film with a uniform film thickness on the substrate surface by controlling the entire surface of the substrate to a uniform temperature distribution.

  The above-mentioned holder is preferably supported in a state where the substrate is floated by a Bernoulli chuck.

  It is preferable that a predetermined gas is supplied between the holder for supporting the substrate in a floating state and the substrate, and a plurality of openings for exhausting the gas flowing between the holder and the substrate are formed on the side surface of the holder. is there.

  With this configuration, it is possible to form a flow path that smoothly flows outside the chamber without causing the supplied gas to stay in the vicinity of the holder.

  A process gas is preferably used as the predetermined gas.

  With this configuration, the substrate can be further supported by the Bernoulli chuck while the film is formed on the substrate surface.

The vapor phase growth method of the present invention comprises:
A vapor phase growth method in which a substrate is housed in a chamber and deposited on the substrate by vapor phase growth,
A step of supporting the substrate in a state of floating the substrate;
Supplying a process gas to the substrate surface supported by the holder to form a crystal film;
It is characterized by providing.

The vapor phase growth method of the present invention comprises:
A vapor phase growth method in which a substrate is housed in a chamber and deposited on the substrate by vapor phase growth,
Heating the substrate;
Supporting the substrate in a floating state by supplying a process gas, and forming a crystal film on the heated substrate surface;
It is characterized by providing.

  With this method, since a space exists between the substrate and the holder, it is possible to suppress the temperature from decreasing at the peripheral edge of the substrate. Therefore, vapor phase growth can be performed in a state where the in-plane temperature distribution of the substrate is uniformly controlled.

According to the present invention, since a space exists between the substrate and the holder, useless heat loss of the substrate can be prevented. Therefore, it becomes possible to control the temperature distribution to be uniform throughout the substrate surface, and a high-quality crystal film with a uniform film thickness can be formed on the substrate surface.
In addition, maintenance for cleaning the crystal film formed on the holder is not necessary, and productivity can be improved.
Furthermore, since vapor phase growth is performed in a state where the substrate and the holder are not in contact with each other, the crystal film is not formed across the substrate surface and the holder surface, and sticking between the substrate and the holder can be prevented.

Embodiment 1. FIG.
First, Embodiment 1 is demonstrated based on figures.
FIG. 1 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 100 according to the first embodiment. FIG. 2 is a conceptual diagram showing a plane of the holder for explaining the process gas flow path 130 according to the first embodiment of the present invention.
A vapor phase growth apparatus 100 in FIG. 1 includes a chamber 101, a holder 103 (also referred to as a susceptor) that is housed in the chamber 101 and supports a wafer 102 that is a substrate, and a crystal film formed on the surface of the wafer 102. A process gas supply unit 104 that supplies a process gas containing raw material components necessary for film formation, an exhaust unit 105 that exhausts the gas in the chamber 101 containing the process gas after film formation, and a surface formed on the wafer 102. A heater 106 is provided for heating to a temperature necessary for film formation.

As shown in FIG. 1, a recess 107 having a predetermined depth is formed on the lower surface of the holder 103 with an inner diameter slightly larger than the diameter of the wafer 102 to be supported. At the center of the surface (ceiling surface) of the recess 107, a process gas supply unit 104 is disposed so as to form a process gas flow path 130 having a predetermined flow rate between the wafer 102 and the holder 103.
The piping of the process gas supply unit 104 is arranged with the tip portion penetrating the holder 103, and also penetrates the upper wall surface of the chamber 101 and is connected to the outside of the chamber 101.

A first discharge unit 108 is provided on the side surface of the distal end portion of the process gas supply unit 104 so as to form a process gas flow path 130 having a predetermined flow rate between the wafer 102 and the holder 103.
A plurality of through-opening portions 109 for smoothly exhausting the process gas discharged from the first discharge unit 108 are provided on the side surface of the recess 107. As a result, a process gas flow path 130 from the process gas supply unit 104 toward the outside of the holder 103 as shown in FIG. 2 can be formed.

Here, the process gas supplied into the chamber 101 is configured by adding a predetermined dopant gas to a mixture of silicon film forming gas trichlorosilane (SiHCl ₃ ) and hydrogen (H ₂ ) as a carrier gas. The
As the dopant gas, boron-based diborane (B ₂ H ₆ ), phosphorus-based phosphine (PH ₃ ), or the like is used. When diborane is added, a p-type conductivity film can be formed, and when phosphine is added, an n-type conductivity crystal film can be formed.

  Further, in order to discharge a flow rate sufficient to form the process gas flow path 130, it is preferable that the diameter of the discharge port of the first discharge portion 108 of the process gas is about 1 mm. However, this numerical value may be varied as necessary.

The exhaust part 105 having a vent hole is provided on the side wall surface of the chamber 101 having a height substantially equal to the height of the opening 109. The exhaust unit 105 is provided with a guide 110 that rectifies the gas flow from the opening 109 so as not to stay.
Further, the exhaust unit 105 is connected to a vacuum pump (not shown) and exhausts the gas in the chamber 101. Therefore, a smooth process gas flow path 130 flowing from the space surrounded by the wafer 102 and the holder 103 to the exhaust unit 105 through the opening 109 can be formed.

The holder 103 in which the above-described gas flow is formed accommodates and supports the recess 107 in a state where the wafer 102 is floated by a negative pressure utilizing the Bernoulli effect and the ejector effect.
In the present embodiment, this support mechanism is called a Bernoulli chuck (hereinafter, the same applies to each embodiment).

For example, assuming that an 8-inch silicon (Si) wafer is supported by a Bernoulli chuck, the wafer 102 is supported in a floating state by setting the flow rate of the supplied gas to 33.8 Pam ³ / s (20 SLM) or more. be able to.

  Since the upper surface of the wafer 102 supported by the Bernoulli chuck is not in contact with the surface of the holder 103 (the ceiling surface of the recess), a temperature decrease due to local heat radiation to the holder 103 can be suppressed. Therefore, the wafer 102 is heated so that the radiant heat from the heater 106 accommodated in the holder 103 is evenly absorbed, and a uniform temperature distribution can be obtained over the entire surface of the wafer 102.

  Then, a thermal decomposition reaction or a hydrogen reduction reaction is performed on the surface of the wafer 102 using a process gas supplied to operate the Bernoulli chuck, and a crystal film is formed on the surface of the wafer 102. Here, if the wafer 102 is in a state of uniform temperature distribution over the entire surface as described above, a high-quality crystal film controlled to have a uniform film thickness can be formed.

FIG. 3 is an enlarged schematic cross-sectional view of the main part in the vicinity of the process gas supply unit 104a in order to explain the film formation state of the crystal film 120 on the surface of the wafer 102 in the first embodiment of the present invention.
In order to operate the Bernoulli chuck, the process gas is discharged from the discharge unit 108 provided in the process gas supply unit 104 a substantially parallel to the surface of the wafer 102 and the holder 103. Then, the portion 120a of the wafer 102 located immediately below the process gas supply unit 104a is less likely to come into contact with the process gas than the other portions of the wafer 102 surface. As a result, the portion 120a located immediately below the process gas supply unit 104a is less likely to form a crystal film than the other portions, and the uniformity of the film thickness of the crystal film 120 over the entire wafer 102 is impaired.

FIG. 4 is a conceptual diagram showing an enlarged cross section of the main part in the vicinity of the process gas supply unit 104b according to another embodiment.
As shown in FIG. 4, the second discharge unit 111 having a relatively small discharge hole with respect to the diameter of the first discharge unit 108 is provided on the surface of the process gas supply unit 104 b facing the wafer 102. This makes it possible to form a process gas flow path 131 for supplying process gas to the portion 120b of the wafer 102 which is difficult to be in contact with the process gas. In the state shown in FIG. The film thickness of the portion 120b that is formed can be compensated.

The inner diameter of the second discharge unit 111 is set to about 1/10 of the size of the first discharge unit 108. For example, when the diameter of the first discharge unit 108 is 1 mm, the inner diameter of the second discharge unit 111 is preferably 0.1 mm.
Thus, the flow rate of the process gas discharged from the second discharge unit 111 is large enough to disturb the flow path 130 of the process gas discharged from the first discharge unit 108 that exhibits the effect of the Bernoulli chuck. It will not be. The flow rate of the process gas discharged from the second discharge unit 111 cancels out the negative pressure generated by the process gas flow 130 discharged from the first discharge unit 108, that is, the buoyancy applied to the wafer 102. The pressure is not generated.
Therefore, it is possible to bring the process gas into contact with the portion 120b of the wafer 102 while maintaining the state in which the wafer 102 is floated by the Bernoulli chuck, and still being difficult to contact the process gas from the first ejection unit 108.

  As a result, the crystal film 120 with a small film thickness error can be formed over the entire surface of the wafer 102.

FIG. 5 is a conceptual diagram showing an enlarged cross section of the main part in the vicinity of the process gas supply unit 104c according to still another embodiment.
As shown in FIG. 5, by setting the piping of the process gas supply unit 104c to a diameter of 2 mm or less, it is possible to reduce the range of the portion 120c where the process gas in the wafer 102 surface is difficult to contact.
If the area of the surface of the piping of the process gas supply unit 104c facing the wafer 102 is reduced, the area of the portion 120c of the wafer 102 that is difficult to contact the process gas is also reduced. Thus, by reducing the thickness of the piping of the process gas supply unit 104, the uniformity of the film thickness of the crystal film 120 formed on the surface of the wafer 102 can be improved.

  The wafer 102 of the present embodiment described above is supported by the holder 103 in a state of being floated in a hollow state. Therefore, heat conduction from the wafer 102 to the holder 103 or the like causes no local heating or heat dissipation. Therefore, if the wafer 102 is evenly heated using the heater 106 housed in the holder 103, a uniform in-plane temperature distribution can be obtained without performing complicated heating control.

The wafer 102 supported by the holder 103 by the Bernoulli chuck described above is in a state of floating in the air. For this reason, the vapor phase growth may be performed in a state where the holder 103 is in contact with the side surface of the outer edge portion of the wafer 102, close to any position of the inner edge portion of the holder 103.
However, the contact between the outer edge side surface of the wafer 102 and the inner edge side surface of the holder 103 is a state where the contact area is small, such as point contact or line contact, and the contact area is limited to only one position. For this reason, compared with a conventional vapor phase growth apparatus, the influence of heat exchange between the wafer 102 and the holder 103 on the temperature distribution in the surface of the wafer 102 is extremely small.

  In the present embodiment, it is not essential to rotate the wafer 102 in order to increase the speed at which the crystal film is formed. However, by rotating the wafer 102, the uniformity of the film thickness of the deposited crystal film can be further enhanced.

FIG. 6 is a conceptual diagram illustrating the state in which the wafer 102 and the holder 103 according to the first embodiment of the present invention are engaged with each other in an enlarged bottom view. FIG. 7 is an enlarged schematic cross-sectional view showing a state where the wafer 102 and the holder 103 in FIG. 6 are engaged.
In order to rotate the wafer 102 supported by the holder 103 while being floated in a hollow state by the Bernoulli chuck, a convex portion 112a is formed on the inner surface of the holder 103 as shown in FIG.
When the wafer 102 is rotated, the wafer 102 is arranged so that a notch 113 (also referred to as a notch) formed for use in alignment and a convex 112a mesh with each other. Since the notch 113 is usually formed only at one place on one silicon wafer, it is sufficient that the protrusion 112a formed on the holder 103 is also provided at one place. As shown in FIG. 7, by making the height of the convex portion 112a substantially the same as the depth of the concave portion 107 formed in the holder 103, the convex portion 112a and the notch 113 can be obtained even if the wafer 102 moves up and down slightly. You can prevent the meshing with.

In this state, the holder 103 connected to a rotation mechanism (not shown) provided outside the chamber 101 is rotated. Then, in association with the rotation of the holder 103, the wafer 102 in which the convex portion 112a and the notch 113 are engaged is rotated. The rotation speed at this time is preferably 10 to 50 min ⁻¹ (rpm).

FIG. 8 is a conceptual diagram corresponding to FIG. 6 according to another embodiment.
As shown in the drawing, the shape of the convex portion may be a tip formed in an R shape. Since the R-shaped convex portion 112b is in contact with the notch 113 at a part of the curved surface, the contact between the wafer 102 and the holder 103 can be engaged with a very small contact area such as point contact or line contact.

  FIG. 9 is a conceptual diagram corresponding to FIG. 6 according to another embodiment. The rectangular convex portion 112c is in contact with the notch 113 at a part of the rectangular side. Therefore, as in the case of the R-shaped convex portion 112, the contact area between the wafer 102 and the holder 103 can be engaged with each other in a very small state.

As described above, it is possible to suppress heat dissipation from the wafer 102 to the holder 103 by forming the convex portion on the holder 103 that reduces the contact area with the wafer 102.
This can reduce the temperature distribution error in the wafer 102 plane, and in addition, in order to perform vapor phase growth while rotating the wafer 102, the uniformity of the film thickness distribution of the crystal film to be formed is improved. This can be further improved.

FIG. 10 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 150 provided with a heating mechanism according to another example of Embodiment 1 of the present invention.
The vapor phase growth apparatus 150 shown in FIG. 10 includes a plurality of lamp heating heaters 160 that heat the wafer 102 outside the chamber 151. Then, a flow path 130 for a process gas having a predetermined flow rate is formed between the wafer 102 and the holder 103, and the wafer 102 is supported in a floating state by a Bernoulli chuck.
If the wafer 102 in such a state is evenly heated by the heater 160, the temperature distribution in the wafer 102 plane can be controlled uniformly.
As described above, in the present embodiment, the means for heating the wafer 102 is not limited to this type, and any means that can uniformly heat the wafer 102 may be used.

  In this embodiment, the two requirements of supplying a raw material component for performing vapor phase growth and forming a gas flow for operating a Bernoulli chuck are one configuration and operation of supplying one kind of process gas. Can be done at the same time. This brings about a great feature that it is not necessary to provide a new gas supply mechanism for operating the Bernoulli chuck in the vapor phase growth apparatus, and it is not necessary to control a plurality of gas supplies.

In the present embodiment, vapor phase growth is performed with the wafer 102 floating in a hollow state. Therefore, the problem that the crystal film formed on the surface of the holder 103, which has been a problem in the past, becomes an obstacle and the wafer cannot be placed or transported is eliminated.
For this reason, it is not necessary to perform maintenance for cleaning the holder surface with HCl or the like, which has conventionally been performed periodically.
Therefore, this embodiment can contribute to the improvement of the productivity of the vapor phase growth apparatus 100.

Further, since vapor phase growth can be performed in a state where the wafer 102 and the holder 103 are not in contact with each other, a crystal film is not formed across the wafer 102 surface and the holder 103 surface, and the wafer 102 and the holder 103 are not formed. Are not stuck by the crystal film. Therefore, it is possible to prevent various problems caused by sticking the wafer and the holder described below.
For example, if the wafer 102 and the holder 103 adhere to each other during vapor phase growth, a portion where the crystal film adheres may be removed when the wafer 102 is transferred, or cracks (cracks, small cracks) may occur. I'll be relaxed. This small scratch becomes a factor that breaks the wafer 102 when polishing and heat treatment are performed in a later semiconductor manufacturing process.
Further, the crystal film may be peeled off when the wafer 102 is transported, and slip (crystal displacement) may occur on the surface of the wafer 102. This becomes a factor that causes the quality of the wafer 102 to deteriorate.
Furthermore, the holder 103 may be removed from a predetermined position by forcibly peeling off the wafer 102 attached to the holder 103. Then, repair such as once disassembling the vapor phase growth apparatus and reassembling the removed member must be performed. This is a factor that decreases the productivity of the vapor phase growth apparatus.

  The above-described sticking between the wafer and the holder is likely to occur when vapor deposition is performed for a long time or when a crystal film having a large film thickness is formed. Here, using this embodiment, if vapor phase growth is performed in a state where the wafer 102 is floated and supported, regardless of conditions such as the length of time for vapor phase growth and the thickness of the crystal film to be deposited, No sticking occurs. Therefore, a desired crystal film can be formed after overcoming the above-described problems.

Embodiment 2. FIG.
FIG. 11 is a conceptual diagram showing a cross-sectional view of the vapor phase growth apparatus 200 according to Embodiment 2 of the present invention. FIG. 12 is a conceptual diagram showing a plane of the holder 203 in order to explain the process gas flow path 230 in the second embodiment of the present invention.
As shown in FIG. 11, a concave portion 207 having a predetermined depth is formed on the upper surface of the holder 203 with an inner diameter slightly larger than the diameter of the wafer 202 to be supported. A process gas supply unit 204 is disposed at the center of the bottom surface of the recess 207 so as to form a process gas flow path 230 having a predetermined flow rate between the wafer 202 and the holder 203.
The piping of the process gas supply unit 204 is arranged with the tip portion penetrating the holder 203, and also penetrates the lower wall surface of the chamber 201 and is connected to the outside of the chamber 201.

On the side surface of the front end portion of the process gas supply unit 204, a discharge unit 208 is provided so as to form a process gas flow path 230 having a predetermined flow rate between the wafer 202 and the holder 203.
A plurality of through openings 209 through which the process gas discharged from the discharge unit 208 is smoothly exhausted are provided on the side surface of the recess 207. Accordingly, a process gas flow path 230 from the process gas supply unit 204 toward the outside of the holder 203 as shown in FIG. 12 can be formed.

Then, the process gas exhausted from the opening 209 to the outside of the holder 203 passes through the exhaust part 205 having a vent provided in the side surface of the chamber 201 and is exhausted to the outside of the chamber 201.
The exhaust unit 205 is provided on the wall surface of the chamber 201 having a height substantially equal to the height of the opening 209. The exhaust unit 205 is provided with a guide 210 that rectifies the gas flow from the opening 209 so as not to stay.
Further, the exhaust unit 205 is connected to a vacuum pump (not shown) and exhausts the gas in the chamber 201. Therefore, it is possible to form a smooth process gas flow path 230 that flows from the space surrounded by the wafer 202 and the holder 203 to the exhaust unit 205 via the opening 209.

  The holder 203 in which the above-described gas flow is formed is accommodated and supported in the recess 207 in a state where the wafer 202 is floated by the Bernoulli chuck.

  The second embodiment uses a holder 203 having a shape that is inverted upside down with respect to the first embodiment, but the space between the wafer 202 and the process gas flow path 230 surrounded by the holder 203 and the outside By adjusting the pressure difference, it is possible to support the wafer 202 in a state of floating in the air.

In this embodiment, the process gas is supplied to the lower surface of the wafer 202, and vapor phase growth is performed with the crystal film growth surface facing downward. For this reason, when particles exist in the chamber 201, the floating particles are less likely to adhere to the growth surface of the wafer 202 due to falling particles.
Particles are fine and soar even with a slight airflow, etc. and fly to various places, but fall according to gravity. Therefore, if the growth surface of the wafer 202 faces upward, the falling particles may be received by the growth surface of the crystal film and contaminated.
However, in this embodiment, since the growth surface of the wafer 202 faces downward, falling particles can be prevented from adhering. Therefore, the wafer 202 manufactured by the vapor phase growth apparatus 200 of this embodiment can prevent contamination by particles.

  In this embodiment, the gas supply at the tip of the process gas supply unit 204, the film thickness distribution of the crystal film given by the size of the piping of the process gas supply unit 204, the heating of the wafer 202 by the heater 206, or each member The description overlapping with the contents of the first embodiment described with reference to FIGS.

Embodiment 3. FIG.
FIG. 13 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 300a according to Embodiment 3 of the present invention.
FIG. 14 is a conceptual diagram showing a plane of the holder 303 for explaining the process gas flow path 330a and the chuck gas flow path 340 in the third embodiment of the present invention.
As shown in FIG. 13, a concave portion 307 having a predetermined depth is formed on the upper surface of the holder 303 with an inner diameter slightly larger than the diameter of the wafer 302 to be supported. A chuck gas supply unit 314 is arranged at the center of the bottom surface of the recess 307 so as to form a chuck gas flow path 340 having a predetermined flow rate between the lower surface of the wafer 302 and the holder 303.
The piping of the chuck gas supply unit 314 is arranged with the tip portion penetrating the holder 303, and also penetrates the lower wall surface of the chamber 301 and is connected to the outside of the chamber 301.

On the side surface of the tip portion of the chuck gas supply unit 314, a discharge unit 308 is provided so as to form a chuck gas channel 340 having a predetermined flow rate in a space surrounded by the lower surface of the wafer 302 and the holder 303. A plurality of through openings 309 are provided on the side surface of the recess 307 to smoothly exhaust the chuck gas discharged from the discharge unit 308. Accordingly, a chuck gas flow path 340 from the chuck gas supply unit 314 to the outside of the holder 303 as shown in FIG. 14 can be formed.
Here, the chuck gas supplied to the holder 303 uses H ₂ or the like. Any chuck gas may be used as long as it does not disturb the environment for vapor phase growth in the chamber 301.

  The holder 303 in which the chuck gas flow 340 is formed is accommodated and supported in the recess 307 in a state where the wafer 302 is floated by the Bernoulli chuck.

  A process gas supply unit 304 a that supplies a process gas to the surface of the wafer 302 is provided above the wafer 302. The piping of the process gas supply unit 304 a passes through the upper wall surface of the chamber 301 and is connected to the outside of the chamber 301. Then, the process gas supplied substantially vertically from the process gas supply unit 304 a is supplied to the upper surface of the wafer 302 supported by the Bernoulli chuck, and changes the direction of flowing substantially horizontally on the surface of the wafer 302. Then, a process gas flow path 330 a that flows outward along the surface of the wafer 302 is formed.

  Here, since the wafer 302 is heated in a state where the Bernoulli chuck is applied, a uniform temperature distribution can be obtained in the entire surface of the wafer 302, as in the first and second embodiments. .

  As described above, the process gas is uniformly supplied from the process gas supply unit 304a to the surface of the wafer 302 heated to a predetermined temperature necessary for vapor phase growth, so that the film thickness is controlled to be uniform. A crystal film can be formed.

  The exhaust unit 305 having a vent hole is provided on the side wall surface of the chamber 301 that is substantially the same as the height of the opening 309 and the surface of the wafer 302. The exhaust unit 305 is provided with a guide 310 that rectifies the gas flow so as not to stay. Further, the exhaust unit 305 is connected to a vacuum pump (not shown) and exhausts the gas in the chamber 301. Therefore, the chuck gas exhausted from the opening 309 and the process gas after film formation can be smoothly exhausted out of the chamber 301.

  In this embodiment, a chuck gas supplied to support the wafer 302 by a Bernoulli chuck and a process gas supplied to form a crystal film on the surface of the wafer 302 are supplied independently. Thereby, the flow rate of the chuck gas can be controlled only to stably support the wafer 302.

  Further, in this embodiment, the process gas can be supplied after determining that the wafer 302 is sufficiently heated to a predetermined temperature necessary for performing vapor phase growth. For this reason, it is possible to perform vapor phase growth at a more constant temperature from the start to the end of vapor phase growth, and it is possible to form a crystal film with a further improved film thickness distribution uniformity. .

Further, another embodiment for supplying a process gas to the surface of the wafer 302 will be described here.
FIG. 15 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 300b including a process gas supply unit 304b according to another example of Embodiment 3 of the present invention.

  As shown in FIG. 15, in the present embodiment, the process gas is supplied so as to form a process gas flow path 330b substantially horizontal to the wafer 302 and along the upper surface of the wafer 302 (crystal film growth surface). May be. Thereby, the vapor phase growth apparatus 300b can design the dimension of a vertical direction compactly with respect to the above-mentioned vapor phase growth apparatus 300a. Therefore, the space of the apparatus can be saved while increasing the uniformity of the film thickness formed on the surface of the wafer 302 supported by the Bernoulli chuck.

Embodiment 4 FIG.
FIG. 16 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 400a according to Embodiment 4 of the present invention. FIG. 17 is a conceptual diagram showing a plane of the holder for explaining the process gas flow path 430a and the chuck gas flow path 440 in the fourth embodiment of the present invention.
As shown in FIG. 16, a concave portion 407 having a predetermined depth is formed on the lower surface of the holder 403 with an inner diameter slightly larger than the diameter of the wafer 402 to be supported. A chuck gas supply unit 414 is disposed at the center of the surface (ceiling surface) of the recess 407 so as to form a chuck gas channel 440 having a predetermined flow rate between the wafer 402 and the holder 403. .
The piping of the chuck gas supply unit 414 is arranged with the tip portion penetrating the holder 403, and also penetrates the upper wall surface of the chamber 401 and is connected to the outside of the chamber 401.

On the side surface of the tip portion of the chuck gas supply unit 414, a discharge unit 408 is provided so as to form a chuck gas channel 440 having a predetermined flow rate between the upper surface of the wafer 402 and the holder 403.
A plurality of through openings 409 are provided on the side surface of the recess 407 to smoothly exhaust the chuck gas discharged from the discharge portion 408. Accordingly, a chuck gas flow path 440 from the chuck gas supply unit 414 to the outside of the holder 403 as shown in FIG. 17 can be formed.
Further, since the type of gas used as the chuck gas is the same as that in the third embodiment, the description thereof is omitted here.

  The holder 403 in which the above-described chuck gas flow 440 is formed accommodates and supports the concave portion 407 in a state where the wafer 402 is floated by the action of a Bernoulli chuck.

Below the holder 403, a heater 406 for heating the wafer 402 is provided. A process gas supply unit 404 a that supplies a process gas to the surface of the wafer 402 is provided in a state of penetrating the center of the heater 406. The piping of the process gas supply unit 404 a passes through the lower wall surface of the chamber 401 and is connected to the outside of the chamber 401.
The process gas supplied from the process gas supply unit 404 a is supplied against the lower surface of the wafer 402 supported by the Bernoulli chuck, and changes the direction of flowing substantially horizontally on the lower surface of the wafer 402. Then, a process gas flow path 430 a that flows outward along the lower surface of the wafer 402 is formed.

  As described above, by supplying the process gas from the process gas supply unit 404a evenly to the lower surface of the wafer 402 onto the surface of the wafer 402 heated to a predetermined temperature necessary for performing vapor phase growth, A crystal film controlled to have a uniform film thickness can be formed.

The exhaust unit 405 having a ventilation hole is provided on the side wall surface of the chamber 401 substantially the same as the height position of the opening 409 and the surface of the wafer 402. The exhaust unit 405 is provided with a guide 410 that rectifies the gas flow so as not to stay.
Further, the exhaust unit 405 is connected to a vacuum pump (not shown) and exhausts the gas in the chamber 401. Therefore, the chuck gas exhausted from the opening 409 and the process gas after film formation can be smoothly exhausted out of the chamber 401.

Further, another embodiment for supplying the process gas to the surface of the wafer 402 will be described here.
FIG. 18 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus 400b including a process gas supply unit 404b according to another example of Embodiment 4 of the present invention.

As shown in FIG. 18, in this embodiment, the process gas is supplied so as to form a process gas flow path 430b that is substantially horizontal to the wafer 302 and along the lower surface of the wafer 302 (crystal film growth surface). May be. Thereby, the vapor phase growth apparatus 400b can design the dimension of a vertical direction compactly with respect to the above-mentioned vapor phase growth apparatus 400a. Further, since the growth surface of the crystal film of the wafer 402 can be set downward, the crystal film formed in this embodiment can reduce contamination by particles. Therefore, it is possible to save space of the apparatus and prevent particle contamination in the apparatus while improving the uniformity of the film thickness formed on the surface of the wafer 402 supported by the Bernoulli chuck.
The heater 406 shown in FIGS. 16 and 18 is housed in the lower portion of the chamber 401. However, as in the other embodiments, the heater 406 may be housed in the recess 407 of the holder 403 or the outside of the chamber 401. You may arrange in.

  Here, the first embodiment includes the improvement in the uniformity of the crystal film formed on the surface of the wafer 402 caused by using the Bernoulli chuck, or the feature brought about by supplying the chuck gas and the process gas independently. About the content which overlaps with description in thru | or Embodiment 3, description is abbreviate | omitted here.

  The embodiments have been described above with reference to specific examples. The present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the scope of the invention.

For example, trichlorosilane has been exemplified as the silicon film forming gas of the process gas, but monosilane (SiH ₄ ), dichlorosilane (SiH ₂ Cl ₂ ), or the like may be appropriately selected and used.

  The epitaxial growth apparatus has been described as an example of the vapor phase growth apparatus of the present invention. However, the present invention is not limited to this, and any apparatus may be used as long as it allows a predetermined crystal film to be vapor grown on the silicon wafer surface. For example, an apparatus for growing a polysilicon film may be used.

  In addition, although descriptions of parts that are not directly required for the present invention, such as apparatus configuration and control method, are omitted, the required apparatus configuration, control method, and the like can be appropriately selected and used.

  In addition, all the vapor phase growth apparatuses that include the elements of the present invention and can be appropriately modified by those skilled in the art, and the shapes of the respective members are included in the scope of the present invention.

1 is a conceptual diagram showing a cross-sectional view of a vapor phase growth apparatus according to Embodiment 1 of the present invention. It is a conceptual diagram which shows the plane of a holder in order to demonstrate the flow path of the process gas in Embodiment 1 of this invention. It is a conceptual diagram which expands and shows the principal part near a process gas supply part in order to demonstrate the film-forming state of the crystal film on the wafer surface in Embodiment 1 of this invention. It is a conceptual diagram which expands and shows the principal part of the vicinity of the process gas supply part concerning another Example. Furthermore, it is a conceptual diagram which expands and shows the principal part of the vicinity of the process gas supply part concerning another Example. It is a conceptual diagram which expands bottom view and shows the state which the wafer and holder of Embodiment 1 of this invention mesh. It is a conceptual diagram which expands and shows the state which the wafer and holder of FIG. 6 mesh. FIG. 7 is a conceptual diagram corresponding to FIG. 6 according to another embodiment. Furthermore, it is a conceptual diagram equivalent to FIG. 6 concerning another Example. It is a conceptual diagram which shows in cross section the vapor phase growth apparatus provided with the heating mechanism concerning the other Example in Embodiment 1 of this invention. It is a conceptual diagram which shows the vapor phase growth apparatus in Embodiment 2 of this invention in cross section. It is a conceptual diagram which shows the plane of a holder in order to demonstrate the flow path of the process gas in Embodiment 2 of this invention. It is a conceptual diagram which shows the vapor phase growth apparatus in Embodiment 3 of this invention in cross section. It is a conceptual diagram which shows the plane of a holder in order to demonstrate the flow path of the process gas and the flow path of chuck gas in Embodiment 3 of this invention. It is a conceptual diagram which shows in cross section the vapor phase growth apparatus provided with the process gas supply part concerning the other Example in Embodiment 3 of this invention. It is a conceptual diagram which shows the vapor phase growth apparatus in Embodiment 4 of this invention in cross section. It is a conceptual diagram which shows the plane of a holder in order to demonstrate the flow path of the process gas and the flow path of chuck gas in Embodiment 4 of this invention. It is a conceptual diagram which shows the vapor phase growth apparatus provided with the process gas supply part concerning the other Example in Embodiment 4 of this invention in cross section. It is a conceptual diagram which shows in cross section the vapor phase growth apparatus of the aspect which makes the conventional board | substrate contact a holder directly, and is supported.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Vapor growth apparatus 101 ... Chamber 102 ... Wafer 103 ... Holder 104a, 104b, 104c ... Process gas supply part 105 ... Exhaust part 106 ... Heater 107 ... Concave part 108 ... 1st discharge part 109 ... Opening part 110 ... Guide 111 ... second discharge parts 112a, 112b, 112c ... convex part 113 ... notch 120 ... crystal film 130 ... process gas flow path

Claims (6)

A chamber;
A holder for supporting the substrate in a floating state in the chamber;
A process gas supply unit for supplying a process gas for forming a crystal film on the substrate surface by vapor deposition into the chamber;
An exhaust section for exhausting the gas in the chamber containing the process gas after film formation to the outside of the chamber;
A vapor phase growth apparatus comprising:   2. The vapor phase growth apparatus according to claim 1, wherein the holder supports the substrate in a floating state by a Bernoulli chuck.   A predetermined gas is supplied between the holder supporting the substrate in a floating state and the substrate, and a plurality of openings for exhausting the gas flowing between the holder and the substrate are formed on a side surface of the holder. The vapor phase growth apparatus according to claim 2.   4. The vapor phase growth apparatus according to claim 3, wherein the process gas is used as the predetermined gas. A vapor phase growth method in which a substrate is housed in a chamber and deposited on the substrate by vapor phase growth,
Supporting the substrate in a floating state with the holder;
Supplying a process gas to the substrate surface supported by the holder to form a crystal film;
A vapor phase growth method comprising: A vapor phase growth method in which a substrate is housed in a chamber and deposited on the substrate by vapor phase growth,
Heating the substrate;
Supporting the substrate in a floating state by supplying a process gas, and forming a crystal film on the heated substrate surface;
A vapor phase growth method comprising: