JP2001140078A - Chemical vapor deposition system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical vapor deposition system with which the uniformity of a film deposition speed distribution and the uniformity of film thicknesses and film quality may be maintained. SOLUTION: This chemical vapor deposition system is constituted by arranging a gaseous raw material supply system for an organic metallic material which is liquid at and under ordinary temperature and atmosphere pressure within a vacuum vessel facing a substrate to be treated and providing the apparatus with a gas introducing port in which the center is located coaxially with the center of the substrate at its center and having a shape gradually narrowed in the distance to the substrate toward the periphery from the peripheral edge of the gas introducing port. The chemical vapor deposition apparatus described above is arranged with a gas flow regulating plate which is arranged in the position coaxial with the center of the substrate, has the shape gradually narrowed in the distance to the substrate toward the periphery from the peripheral edge of the gas introducing port and has a gap part allowing the transmission of part of the gas flowing-in from the gas introducing port toward the substrate in such a manner that this gas flow regulating plate faces the substrate between the substrate and the gas introducing guide while having a gap from the surface of the gas introducing guide facing the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical vapor deposition apparatus for forming a thin film by utilizing a chemical reaction of a reactive gas. In this case, the present invention relates to a chemical vapor deposition apparatus capable of maintaining good uniformity of a film forming rate distribution on a substrate surface even when the size of the substrate is increased.

[0002]

2. Description of the Related Art In the production of large-scale integrated circuits (LSI), liquid crystal displays (LCD), and the like, there is a step of forming a predetermined thin film on the surface of a substrate. In producing such a thin film, a chemical vapor deposition (CVD) apparatus for producing a thin film using a chemical reaction of a reactive gas is widely used because a thin film having a required composition can be relatively freely formed. ing.

[0003] In recent years, in film formation of metal materials, CVD using an organic metal compound which is liquid at normal temperature and normal pressure as a raw material is used.
Has been actively researched. For example, in the field of metal materials for wiring, copper (Cu) having high migration resistance and low specific resistance is considered to be a promising next-generation wiring material. In Cu CVD film formation, [trimethylvinylsilyl] is used. Hexafluoroacetylacetonate copper (hereinafter C
An organic metal compound that is liquid at normal temperature and pressure, such as u (hfac) (abbreviated as tmvs), may be used as a raw material.

FIG. 7 is a schematic front view showing the structure of a conventional chemical vapor deposition apparatus disclosed in Japanese Patent Application Laid-Open No. H10-60650. The vacuum vessel 1 shown in FIG.
1 and a substrate 12 to be processed at a predetermined position in a vacuum vessel 11
, A heating means 14 for heating the substrate 12 to a predetermined temperature, and a source gas supply system 15 for supplying a source gas to the surface of the heated substrate 12. This is a chemical vapor deposition apparatus configured to form a predetermined thin film on the surface of the substrate 12 using a chemical reaction on or near the surface of the substrate 12. The chemical vapor deposition apparatus shown in FIG. 7 includes a gas introduction guide 16 arranged in the vacuum vessel 11 so as to face the substrate 12 held by the substrate holder 13 and a source gas supply system 1.
5 is provided. The gas introduction guide 16 is a gas introduction port to which the gas introduction pipe 17 of the source gas supply system 15 is connected at the center thereof, and is disposed at a position where the center is coaxial with the center of the substrate 12. It has a gas inlet 16a and has a characteristic shape such that the distance from the substrate 12 to the substrate 12 gradually decreases from the periphery of the gas inlet 16a toward the periphery thereof.

[0005] In the conventional example shown in FIG.
As No. 5, an apparatus using a liquid raw material is exemplified.
That is, the raw material gas supply system 15 includes a raw material container 21 storing the liquid raw material, a vaporizer 22 for vaporizing the liquid raw material sent from the raw material container 21, and a gas for transmitting the raw material gas vaporized by the vaporizer 22 to the vacuum container 11. It comprises a valve 23 provided in the introduction pipe 17 and a flow controller (not shown), and the end of the gas introduction pipe 17 is connected to the gas introduction port 1 of the gas introduction guide 16.
6a.

[0006] The operation of the conventional chemical vapor deposition apparatus having the above-described configuration will be described by taking as an example a copper CVD film formation using Cu (hfac) (tmvs) as a raw material. First,
The substrate 12 is transferred to the vacuum vessel 1 using a substrate transfer means (not shown).
After being transported into the substrate 1, the substrate 12 is held by the substrate holder 13, and the pressure is reduced to a predetermined pressure. By adjusting the heating means 14, the temperature of the substrate 12 is reduced to about 100 to 300 ° C.
Heat. In this state, Cu (hfac) (tmv
s) is vaporized by a vaporizer 22 and mixed with a rare gas such as hydrogen, nitrogen or argon as a carrier gas, and the mixture is mixed with a gas introduction pipe 17, a gas introduction port 16 a, and a gas introduction guide 16.
And is introduced into the vacuum vessel 11 through Cu introduced
The gas of (hfac) (tmvs) is gaseous phase and substrate 12
A chemical reaction occurs near the surface, and copper is deposited on the surface of the substrate 12.

[0007] At this time, in the chemical vapor deposition apparatus shown in FIG.
As it goes around the substrate 12, that is, the gas inlet 1
6a has a shape that gradually narrows from the periphery of the gas introduction guide 16 toward the periphery of the gas introduction guide 16, so that the thickness of the boundary layer formed near the surface of the substrate 12, that is, formed near the surface of the substrate 12, It is possible to suppress an increase in the thickness of the region where the diffusion of gas molecules is dominant. As a result, in-plane uniformity of the film thickness and film quality could be improved.

[0008]

In the conventional chemical vapor deposition apparatus having the above structure, it is important to increase the size of the substrate and increase the film forming speed in order to improve the productivity. . Further, it is also required to improve the use efficiency of the organic metal compound raw material which is liquid at normal temperature and normal pressure.

It has been expected that an increase in the size of the substrate can be dealt with by increasing the flow rate of the source gas and increasing the size of the gas introduction guide. However, an increase in the size of the gas introduction guide or the increase in the flow rate of the source gas is expected. At the same time, the gas flow changes,
It can be seen that the film deposition rate distribution becomes non-uniform, and only by using the structure of the conventional chemical vapor deposition apparatus, the size of the substrate is increased while maintaining the uniformity of the film thickness and film quality within the substrate surface, and
It was found that it was difficult to cope with an increase in the film forming speed. The reason will be described with reference to the accompanying drawings.

FIGS. 8A and 8B schematically show the flow of gas near the substrate 12 in a conventional chemical vapor deposition apparatus corresponding to a 6-inch substrate. FIG. 8 (a)
Shows the case where the flow rate of the source gas to be introduced is small. On the other hand, FIG. 8B shows a case where the flow rate of the source gas to be introduced is large.

The specific conditions under which the flow of the gas changes depend not only on the flow rate of the raw material gas but also on the pressure and the size of the gas inlet 16a. However, as the flow rate of the raw material gas is increased, the inertial force of going straight toward the substrate 12 becomes superior to the viscous force generated along the gas introduction guide 16 as shown in FIG. A circulating flow will always occur.

The manner in which the gas flow changes also applies when the size of the substrate 12 to be processed is increased. As an example, it is assumed that the dimensions of each part are increased at the same ratio in order to increase the dimensions of the substrate. In order to maintain the film forming rate, the flow rate of the raw material gas needs to be increased in proportion to the area of the substrate, and therefore needs to be increased by the square of the dimensional ratio. As a result of the cross-sectional area of the gas inlet 16a also increasing as the square of the dimensional ratio, the average flow velocity at the gas inlet 16a is the same as when the substrate size is small. On the other hand, the influence of the viscosity generated between the gas introduction guide 16 and the wall rapidly decreases as the distance from the wall increases, and becomes substantially zero when the distance from the wall exceeds a certain value. As a result, the flow toward the substrate tends to be more dominant, and a circulating flow is easily formed.

From the above description, in the case where the dimensions of the apparatus are the same and the flow rate increases, or in the case where the deposition rate is to be kept constant even if the size of the substrate is increased, the gas introduction guide 16 is used in both cases. In the space formed between the substrate and the substrate 12, FIG.
(B) As shown in the figure, it can be seen that a circulating flow is easily generated. Therefore, in the following description of the gas flow, when describing the problems of the conventional chemical vapor deposition apparatus, only the case where the flow rates are different will be described. However, as described above, the same result is qualitatively obtained even when the substrate size is increased.

FIGS. 9A and 9B schematically show the concentration distribution of gas (intermediate product) near the substrate 12 in a conventional chemical vapor deposition apparatus corresponding to a 6-inch substrate.
FIG. 9A shows a case where the flow rate of the source gas to be introduced is small, and FIG. 9B shows a case where the flow rate of the source gas to be introduced is large.
Here, the intermediate product is considered to be Cu (hfac), and the concentration distributions shown in FIGS. 9A and 9B qualitatively show the results of computer simulation.

9 (a) and 9 (b), the concentration distribution of the intermediate product is different, and as a result, it is considered that the distribution of the copper deposition rate is different.

Here, in order to make it easy to understand the relationship between the concentration distribution of the intermediate product and the distribution of the copper deposition rate, a mechanism for depositing copper will be described.

"The role of gas phase reactions during chemical vapor deposition of copper from Cu (hfac) (tmvs)" (The R
ole of Gas-Phase Reaction
sduring Chemical Vapor De
position of Copper from (h
fac) Cu (tmvs) "(J. Ele
trochem. Soc. , Vol. 145,
No. 12, December 1998 No. 422
According to page 6 to page 4233), Cu (hfac) (tmvs) as a raw material gas is Cu (hfac) in the gas phase.
fac) and tmvs. Further, Cu (hfa
c) is adsorbed on the substrate, and copper is deposited by a surface reaction of Cu (hfac). The reaction formula is as follows.

Cu (hfac) (tmvs) → Cu (h
fac) + tmvs 2Cu (hfac) → Cu + Cu (hfac) ₂

Since the flux of Cu (hfac) depends on the diffusion speed of gas molecules near the very surface of the substrate 12 where the flow velocity is extremely slow, the boundary layer (diffusion is dominant) formed near the surface of the substrate 12 Area is larger, the smaller the thickness.

Therefore, in the conventional chemical vapor deposition apparatus shown in FIG. 7, the gas introduction guide 16 has a shape in which the distance from the substrate 12 gradually decreases from the periphery of the gas introduction port 16a to the periphery. In addition, the structure in which the thickness of the boundary layer is suppressed from increasing at the end of the substrate 12 and the uniformity of the film forming rate is maintained.

However, when a circulating flow as shown in FIG. 8B is formed in a region between the substrate 12 and the gas introduction guide 16, the difference in the concentration of Cu (hfac) is reduced. It became clear from the result of the computer simulation that it became large in the center part and the end part of the.

That is, in the schematic diagram shown in FIG. 9B in the case where the flow rate of the source gas to be introduced is large, it is shown that many lines showing the contours of the concentration cross the substrate 12, and the gradient of the concentration is shown in FIG. This shows that it is larger than that of FIG. Further, as a result of the formation of the circulating flow, the thickness of the boundary layer near the center of the substrate 12 is expected to be thinner than when the circulating flow is not formed, and Cu (hf
It is conceivable that the stay time of ac) is prolonged, and that Cu (hfac) is consumed much near the center of the substrate 12.

FIG. 10 shows a film-forming speed distribution when a film is formed on a 6-inch substrate using the conventional chemical vapor deposition apparatus shown in FIG. In the case of (a) in which the source gas is introduced at a flow rate generally adopted when forming a film on a conventional 6-inch substrate, the uniformity of the film forming rate distribution is maintained. On the other hand, when a film is formed on a conventional 6-inch substrate, the flow rate of the raw material gas is increased to a flow rate larger than the flow rate of the generally used raw material gas. It can be seen that the film deposition rate distribution was deteriorated.

As described above, the deterioration of the film deposition rate distribution is caused by the difference between the substrate 12 and the gas introduction guide 16 shown in FIG.
(B) It is considered that the main cause is that the circulating flow as shown is formed.

According to the present invention, in the conventional chemical vapor deposition apparatus whose example is shown in FIG. 7, a gas introduction guide is used to cope with an increase in substrate size and an increase in film forming speed in order to improve productivity. Even in the case where the size of the substrate 16 is increased and the flow rate of the source gas is increased, the circulation flow as shown in FIG. To provide a chemical vapor deposition apparatus that can prevent the formation of a gas, can maintain uniformity of the film forming rate distribution, uniformity of the film thickness and film quality in the substrate surface, and have excellent use efficiency of the source gas. It is an object.

[0026]

To solve the above-mentioned problems, a chemical vapor deposition apparatus proposed by the present invention comprises a vacuum vessel provided with an exhaust system and a substrate holding a substrate to be processed at a predetermined position in the vacuum vessel. A holder, heating means for heating the substrate to a predetermined temperature, and a source gas supply system for supplying a source gas to the surface of the heated substrate, wherein the substrate is subjected to a chemical reaction on or near the surface of the substrate using a chemical reaction. A chemical vapor deposition apparatus for producing a predetermined thin film on a surface of a substrate, wherein the source gas supply system is disposed in a vacuum vessel so as to face a substrate held by the substrate holder, and the source gas supply system is provided at the center thereof. A gas introduction port to which a gas introduction pipe of a supply system is connected, the gas introduction port having a center disposed at a position coaxial with the center of the substrate, and a peripheral edge of the gas introduction port. From In a chemical vapor deposition apparatus having a gas introduction guide having a shape in which the distance from the substrate gradually decreases as the head goes, the gas is introduced between the substrate held by the substrate holder and the gas introduction guide. A gas rectifying plate arranged so as to face the substrate is provided while having a gap between the introduction guide and the surface facing the substrate, and the gas rectifying plate has a center located at the center of the substrate. And a shape that the distance from the substrate is gradually narrowed from the center of the gas rectifying plate toward the periphery thereof, and furthermore, the gas flowing from the gas introduction port. Is a chemical vapor deposition apparatus characterized in that a part of the substrate is provided with a void portion that can be transmitted toward the substrate.

Here, the gap provided in the gas straightening plate is formed by a plurality of through holes or a plurality of through holes provided in the gas straightening plate.
It can be a through groove or both a through hole and a through groove. These through-holes and through-grooves allow a part of the gas flowing from the gas inlet to pass through these through-holes and through-grooves and flow in the direction of the substrate to be processed. In the region between the substrate 12 to be processed and the gas introduction guide 16, it is possible to contribute to preventing the formation of a circulating flow as shown in FIG. In addition to making it possible to maintain good uniformity of the film thickness and film quality in the substrate surface, the size, number, and gas rectification are not limited as long as the use efficiency of the source gas does not decrease. There are no restrictions on the size of the plate, the distance between the gas straightening plate and the gas introduction guide 16, and the like.

However, the flow of gas passing through these through-holes and through-grooves and heading toward the substrate 12 is directed to the center of the gas rectifying plate disposed at a position coaxial with the center of the substrate 12. On the other hand, since it is preferable that the flow becomes axially symmetric in order to prevent the formation of the above-mentioned circulating flow, the gas rectifying plate is disposed at a position where the through hole and the through groove are coaxial with the center of the substrate 12. Is preferably provided concentrically and diametrically symmetric with respect to the center.

[0029]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In each of the drawings used in the following description, each component is only schematically shown in shape, size, and positional relationship so that the present invention can be understood. In addition, in each of the attached drawings, the same components are denoted by the same reference numerals, and duplicate description thereof may be omitted. Furthermore, the numerical conditions given in the following description are only preferred examples within the scope of the present invention. That is, the invention according to this application is not limited only to these conditions.

The apparatus shown in FIG. 1 has a vacuum vessel 11 provided with an exhaust system 10, a substrate holder 13 for holding a substrate 12 to be processed at a predetermined position in the vacuum vessel 11, and heats the substrate 12 to a predetermined temperature. Heating means 14 and heated substrate 12
And a source gas supply system 15 for supplying a source gas to the surface of the substrate 12, and forming a predetermined thin film on the surface of the substrate 12 by utilizing a chemical reaction of the supplied source gas on or near the surface of the substrate 12. It is a configured chemical vapor deposition apparatus.

The source gas supply system 15 has a gas introduction guide 16 disposed in the vacuum vessel 11 so as to face the substrate 12 held by the substrate holder 13. And the source gas supply system 1
Gas introduction port 16a to which the gas introduction pipe 17 is connected
It has. The center of the gas introduction port 16a is disposed at a position coaxial with the center of the substrate 12, and the distance between the gas introduction guide 16 and the substrate 12 gradually decreases from the periphery of the gas introduction port 16a toward the periphery thereof. It is formed as follows.

In the chemical vapor deposition apparatus of the present invention, as shown in FIG. 1, between the substrate 12 held by the substrate holder 13 and the gas introduction guide 16, the surface of the gas introduction guide 16 facing the substrate 12 The substrate 12 has a gap between
There is provided a gas straightening plate 30 arranged so as to be opposed to. The gas flow plate 30 is shown in FIGS. 1, 2 (b) and 3
(B) As shown, it is supported by the support rod 35, and its center is disposed at a position coaxial with the center of the substrate 12, and the distance from the center of the gas rectifying plate 30 to the periphery of the gas rectifier plate 30 increases. Has a shape that gradually narrows. The gas flow plate 30 is connected to the gas inlet 16a.
2A is provided as a through-hole 31 or a through-groove 32 shown in FIG.

In the chemical vapor deposition apparatus of the present invention, as a result of the provision of the gas rectifying plate 30 as described above, a part of the source gas introduced through the gas inlet 16a is disposed on the gas rectifying plate 30. When the gas passes through the through hole 31 or the through groove 32 and the gas flow rate is large or the substrate size 12 increases, a circulating flow is formed in the space formed by the substrate 12 and the gas introduction guide 16. Can be prevented.

Incidentally, in the case of a rectifying plate generally called a shower head, the gas introducing guide 16 and the rectifying plate as in the apparatus shown in the present invention have a structure connected over the entire circumference. According to the apparatus of the present invention, all of the gas is supplied to the gas straightening plate 30 through the through hole 31 or the through groove 3.
It does not pass through 2. A part of the raw material gas introduced through the gas introduction port 16a passes through the through hole 31 and the through groove 32 toward the substrate 12, and the remaining gas includes the gas introduction guide 16 and the gas rectifying plate 30. Between the gas introduction guide 16 and the gas baffle plate 3
The flow passing between the zero peripheral edge and the outer peripheral portion of the substrate 12 is not directly obstructed. This is because one of the objects of the chemical vapor deposition apparatus of the present invention is to prevent the occurrence of a circulating flow that deteriorates the uniformity of the film forming rate distribution while taking advantage of the conventional apparatus. The gas rectifying plate 30 employed in the above device has a purpose and a structure different from those of a conventionally used shower head.

FIG. 2 shows a first example of the structure of the gas flow regulating plate 30. FIG. 2 shows a gas rectifying plate 30 in which a plurality of through holes 31 are arranged at five concentric positions, that is, five groups of through holes are provided at five concentric positions. Things. The diameter of the through hole 31 is
2 to 10 mm is preferred. In addition, the series of through-hole groups arranged concentrically is preferably 3 to 10 groups. It is desirable that the value of the diameter of the through hole 31 and the number of the through hole group increase as the size of the substrate 12 increases.

FIG. 3 shows another example of the structure of the gas flow regulating plate 30. FIG. 3 shows a gas straightening plate 30 in which four divided through grooves 32 are arranged at five concentric positions, that is, five groups of through grooves are provided at five concentric positions. Is represented. The width of the through groove 32 is preferably 2 to 8 mm. The series of through-grooves arranged concentrically is preferably 3 to 10 groups. The number of divisions of the through-grooves 32 arranged on the same radius is not particularly limited, but it is desirable that the flow of gas passing therethrough is close to axial symmetry. It is desirable that the groove width of the through groove 32 and the number of the through groove group increase as the size of the substrate 12 increases.

The lower limit value of the diameter of the through hole 31 described above,
The lower limit value of the width of the through groove 32 is determined so that the through hole 31 and the through groove 32 are not clogged by Cu deposited on the gas flow regulating plate 30. The distance between the adjacent through holes 31, 31 above,
The distance between the adjacent through grooves 32, 32, the distance between the through holes provided on the adjacent radii, the distance between the through grooves provided on the adjacent radii, and the concentric arrangement. Number of series of through-hole groups and through-groove groups to be performed (3 to 10)
For example, while taking into account the flow rate of the source gas, it is possible to prevent the formation of a circulating flow in the space formed by the substrate 12 and the gas introduction guide 16, and to prevent the use efficiency of the source gas from decreasing. It can be determined appropriately within the range.

It should be noted that the gas rectifying plate having the combination of the through hole 31 and the through groove 32 can have a structure capable of passing substantially the same gas flow rate, and is limited to only one of the conditions. Not something.

In the embodiment shown in FIGS. 2 and 3, the gas straightening plate 30 is supported by three support rods 35.
This is also merely an example, and the substrate held by the substrate holder 13 is not limited as long as the gas introduced through the gas inlet 16a is not hindered from flowing smoothly and the gas rectifying plate 30 can be stably supported. There is no particular limitation on the configuration and structure of disposing the gas rectifying plate 30 between the gas introduction guide 16 and the gas introduction guide 16 so as to face the substrate 12.

Next, the operation of the chemical vapor deposition apparatus of the present invention will be described by taking as an example a copper CVD film formation using Cu (hfac) (tmvs) as a raw material. First, the substrate 12 is transferred into the vacuum chamber 11 using a substrate transfer unit (not shown), and then the substrate 12 is held by the substrate holder 13.
The pressure is reduced to a predetermined pressure. By adjusting the heating means 14, the substrate 12 is heated to a temperature of about 100 to 300C. In this state, Cu (hfac) (tmvs) is vaporized by the vaporizer 22, mixed with a rare gas such as hydrogen, nitrogen or argon as a carrier gas, and vacuumed through the gas introduction pipe 17 and the gas introduction port 16a. It is introduced into the container 11. The introduced Cu (hfac) (tmvs) gas is guided by the gas introduction guide 16 and, while being rectified by the gas rectification plate 30, causes a chemical reaction in the gas phase and in the vicinity of the surface of the substrate 12, thereby causing a chemical reaction on the surface of the substrate 12. Copper deposits.

FIG. 4 shows a case where a film is formed on a 6-inch substrate using the chemical vapor deposition apparatus of the present invention employing the gas rectifying plate 30 shown in FIG. If the flow rate of the conventional chemical vapor deposition apparatus shown in FIG.
The flow of the gas near the substrate 12 (6 inches) when the source gas is introduced at a flow rate at which a circulating flow is formed in the space between the substrate 12 and the gas introduction guide 16 is schematically shown. I have.

As a result of arranging the gas flow regulating plate 30 in the space between the substrate 12 and the gas introduction guide 16, even in the conventional chemical vapor deposition apparatus, even under the process conditions in which a circulating flow is formed, a circulating flow is not generated. It became clear by computer simulation that it became a flow. As a result, as shown in FIG. 5, the concentration distribution of the intermediate product which directly affects the deposition rate of copper near the substrate 12 is improved.

A chemical vapor deposition apparatus of the present invention employing the gas rectifying plate 30 shown in FIG. 2 is the same as the chemical vapor deposition device of FIG. Considering a conventional chemical vapor deposition apparatus, when forming a film on a 6-inch substrate by introducing a source gas at the same flow rate adopted in the study of FIG. 4 when forming a film on a 6-inch substrate, respectively. Was analyzed for the film deposition rate distribution of copper by computer simulation, and the result of FIG. 6 was obtained.

That is, in the case of the conventional chemical vapor deposition apparatus shown by (b) in FIG. 6, the film forming speed in the substrate surface is not uniform. It can be seen that in the case of the chemical vapor deposition apparatus of the present invention, the uniformity of the film forming rate in the substrate surface is remarkably improved.

In this embodiment, the gas introduction guide 16 is formed such that the distance from the gas introduction port 16a to the substrate 12 gradually decreases from the periphery to the periphery thereof. A gas introduction guide 16 having a shape in which a surface facing the surface 12 forms part of a conical slope coaxial with the center of the substrate 12 is used,
The gas straightening plate 30 has a shape similar to the shape of the gas introduction guide 16, is disposed at a position where the center thereof is coaxial with the center of the substrate 12, and the distance from the substrate 12 gradually increases toward the periphery. Although the present invention has been described by adopting one having a narrower shape, the present invention is not limited to such an embodiment.

In other words, the gas introduction guide 16 is formed so that the distance from the substrate 12 to the periphery of the gas introduction port 16a gradually decreases from the periphery to the periphery of the gas introduction port 16a. , Substrate 12
Of the substrate 12 from the central axis.
Let r be the distance to an arbitrary point on the surface facing the surface and h be the distance between the point and the substrate 12 at that point, a hyperbola whose product of r and h is substantially constant regardless of the size of r is Part of a hyperboloid of revolution obtained by rotating around the central axis,
Alternatively, a gas introduction guide 16 formed so as to form a part of a rotating curved surface obtained by rotating a curve in which the product of r and h decreases as r increases around the central axis is used. The gas straightening plate 30 may have a shape similar to the shape of the gas introduction guide 16.

In any case, the thickness of the boundary layer formed near the surface of the substrate 12, that is, the thickness of the region formed near the surface of the substrate 12 where the diffusion of gas molecules is dominant is suppressed from increasing. The shape of the gas introduction guide 16 adopted from a hydrodynamic point of view, that is, the substrate 12 moves from the periphery of the gas introduction port 16a to the periphery thereof.
The shape of the gas introduction guide 16 is similar or approximate to the shape of the gas introduction guide 16 formed so that the gap with the surface is gradually narrowed. Substrate 12 toward the periphery
The gas rectifying plate 30 having a shape in which the distance from the gas rectifying plate 30 gradually narrows, and having a gap through which a part of the gas flowing from the gas introduction port can pass toward the substrate 12, The gas introduction guide 16 is disposed so as to face the substrate 12 while keeping a gap between the gas introduction guide 16 and the surface facing the substrate 12, and is disposed in a space formed by the substrate 12 and the gas introduction guide 16. The formation of a circulating flow of the source gas can be prevented, and the uniformity of the film forming speed, the uniformity of the film thickness and the film quality within the substrate surface can be maintained well without lowering the use efficiency of the source gas. All configurations are included in the technical scope of the present invention.

According to the chemical vapor deposition apparatus of the present invention, even when the flow rate of the raw material gas is increased as compared with the conventional chemical vapor deposition apparatus, the substrate to be processed and the gas introduction guide of the raw material gas supply system can be used. It is possible to prevent a gas circulating flow from occurring in the space formed between them, and it is possible to maintain good uniformity of the film forming speed distribution, uniformity of the film thickness and film quality within the substrate surface,
Moreover, these can be realized without lowering the use efficiency of the raw material gas. Further, even when the substrate size is increased, it is possible to cope with the conventionally obtained uniformity of the deposition rate, the uniformity of the film thickness and the film quality in the substrate surface, and the efficiency of using the source gas.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a first embodiment of the chemical vapor deposition apparatus of the present invention.

FIGS. 2A and 2B are views showing the structure of a gas flow plate employed in the chemical vapor deposition apparatus of the present invention, wherein FIG. 2A is a plan view and FIG.

FIGS. 3A and 3B are views showing the structure of another gas flow regulating plate employed in the chemical vapor deposition apparatus of the present invention, wherein FIG. 3A is a plan view and FIG.
Is a side view.

FIG. 4 is a view showing a flowing direction of a gas near a substrate in the chemical vapor deposition apparatus shown in FIG. 1;

FIG. 5 is a view showing a concentration distribution of a gas (intermediate product) near a substrate in the chemical vapor deposition apparatus shown in FIG. 1;

FIG. 6 is a diagram comparing film deposition rate distributions when a film is formed using the chemical vapor deposition apparatus of the present invention shown in FIG. 1 and a conventional chemical vapor deposition apparatus.

FIG. 7 is a schematic front view of a conventional chemical vapor deposition apparatus.

8A and 8B are diagrams illustrating a direction in which a gas flows in the vicinity of a substrate in a conventional chemical vapor deposition apparatus, and FIG. 8A illustrates a direction in which a gas flows when a flow rate of a source gas to be introduced is small;
(B) is a diagram showing the flow direction of the gas when the flow rate of the source gas to be introduced is large.

FIG. 9 is a diagram showing a concentration distribution of a gas (intermediate product) in the vicinity of a substrate in a conventional chemical vapor deposition apparatus, where (a) is a diagram showing a concentration distribution when a flow rate of a source gas to be introduced is small; FIG. 3B is a diagram showing a concentration distribution when the flow rate of the source gas introduced is large.

FIG. 10 is a diagram showing a film forming speed distribution in a conventional chemical vapor deposition apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Exhaust system 11 Vacuum container 12 Substrate 13 Substrate holder 14 Heating means 15 Source gas supply system 16 Gas introduction guide 16a Gas introduction port 17 Gas introduction pipe 21 Source container 22 Vaporizer 30 Gas straightening plate 31 Through hole 32 Through groove

Claims (1)

[Claims] 1. A vacuum container provided with an exhaust system, a substrate holder for holding a substrate to be processed at a predetermined position in the vacuum container, heating means for heating the substrate to a predetermined temperature, and a surface of the heated substrate A source gas supply system for supplying a source gas to the substrate, and a chemical vapor deposition apparatus that generates a predetermined thin film on the surface of the substrate by using a chemical reaction on or near the surface of the substrate, the source gas supply system comprising: The system is disposed in a vacuum vessel so as to face the substrate held by the substrate holder, and a gas introduction port to which a gas introduction pipe of the source gas supply system is connected at the center, and the center is the gas introduction port. A gas inlet is provided at a position that is coaxial with the center of the substrate, and has a shape in which the distance from the substrate gradually decreases from the periphery of the gas inlet toward the periphery. Gas introduction In a chemical vapor deposition apparatus comprising a guide, between the substrate held by the substrate holder and the gas introduction guide, the substrate having a gap between a surface of the gas introduction guide facing the substrate and The gas straightening plate is provided so as to face the gas straightening plate, and the gas straightening plate is arranged at a position where the center thereof is coaxial with the center of the substrate, and the gas straightening plate is positioned from the center of the gas straightening plate. It has a shape in which the distance from the substrate gradually decreases toward the periphery, and further includes a void portion through which a part of the gas flowing from the gas introduction port can be transmitted toward the substrate. Chemical vapor deposition equipment.