JPH11158632A - Thin film vapor phase growth apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a thin film vapor phase growth apparatus which consists of compact constitution and is capable of stably executing a deposition treatment with uniform and high quality on a substrate. SOLUTION: This thin film vapor phase growth apparatus is constituted by providing an airtight deposition chamber 10 with a substrate holding means 12 which holds a substrate W, a lifting mechanism 14 for lifting this substrate holding means between at least a deposition position and a transportation position, a gas injection head 16 for injecting gaseous raw materials for injecting toward the substrate, a substrate transporting port 20 opening to the height corresponding to the transportation position of the side wall 18 of the deposition chamber and a discharge port 22 opened to the height between the deposition position of the side wall of the deposition chamber and the transportation position. The deposition chamber is provided with a flow regulating plate 44 for adjusting the flow of the reacted gases. This flow regulating plate has a cylindrical plate 48 enclosing the lifting route of the substrate holding means and a first annular plate 50 for vertically partitioning the space in the deposition chamber at the height between the discharge port and the substrate transporting port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film vapor deposition apparatus for vapor-depositing a high dielectric or ferroelectric thin film such as barium / strontium titanate on a substrate.

[0002]

2. Description of the Related Art In recent years, the degree of integration of integrated circuits in the semiconductor industry has been remarkably improved, and research and development of DRAMs from the current megabit order to the future gigabit order have been conducted. To manufacture such a DRAM,
A capacitor element that can obtain a large capacity with a small area is required. A tantalum pentoxide (Ta ₂ O ₅ ) thin film having a dielectric constant of about 20, instead of a silicon oxide film or a silicon nitride film having a dielectric constant of 10 or less, as a dielectric thin film used for manufacturing such a large-capacity element. Or a metal oxide thin film material such as barium titanate (BaTiO ₃ ) having a dielectric constant of about 300, strontium titanate (SrTiO ₃ ), or barium strontium titanate ((Ba, Sr) TiO ₃ ) obtained by mixing these materials. Promising.

[0003] When such a metal oxide thin film is vapor-phase grown on a substrate, the substrate is placed on a susceptor (heating and holding unit) arranged in an airtight film forming chamber, and the inside of the susceptor is heated. A mixed gas of a source gas and a reactive gas (oxygen-containing gas) is directed toward the substrate W from a gas injection head installed inside the film forming chamber while heating the substrate to a predetermined temperature by a heating means such as a heater built in the substrate. A thin film vapor phase growth apparatus for spraying is used.

[0004]

In order to uniformly form a film in such a film forming method, it is necessary to control the flow while taking into account the path of contact between the gas injected from the gas injection head and the substrate. Yes, this must take into account not only the path from the gas injection head to the substrate, but also the entire flow, including the exhaust path from the deposition chamber.

For example, it is conceivable to form an axisymmetric gas flow surrounding the substrate by opening an exhaust port of the film forming chamber just below the substrate, but a support shaft of the holder and a lifting mechanism below the substrate holder. Not only is it difficult to provide an exhaust port at such a position, but also the gas path in the film formation chamber becomes longer, and deposition or reactant adheres to these parts to cause a contamination source. May be. On the other hand, a method is also conceivable in which a plurality of exhaust ports are opened outward from the holder to approximate an axially symmetric flow.However, the apparatus protrudes outward and enlarges, the floor occupied area becomes large, and the exhaust port and substrate transport Design difficulties such as interference at the exit are also great.

In view of the above, it is an object of the present invention to provide a thin film vapor phase growth apparatus which has a compact structure and can stably perform a uniform and high quality film forming process on a substrate. .

[0007]

According to the present invention, there is provided a substrate holding means for holding a substrate in an airtight film forming chamber, an elevating mechanism for moving the substrate holding means up and down at least between a film forming position and a transfer position, A gas injection head for injecting a source gas for film formation toward the substrate, a substrate transfer port opened at a height corresponding to the transfer position on the side wall of the film formation chamber, and a transfer between the film formation position on the side wall of the film formation chamber and the transfer In a thin film vapor phase growth apparatus provided with an exhaust port opening at a height between positions, a rectifying plate for adjusting a flow of a reacted gas is provided in the film forming chamber, and the rectifying plate is provided on the substrate. A thin-film vapor phase growth apparatus comprising: a cylindrical plate surrounding a lifting path of a holding unit; and a first annular plate partitioning a space inside a film formation chamber up and down at a height between the exhaust port and the substrate transfer port.

Thus, the upper space contributing to the film formation and the lower space for taking in and out of the substrate can be divided to control the gas flow and to form stable film formation conditions. Further, by forming a ring-shaped flow path that guides the reacted gas in the film forming chamber to the exhaust port by the rectifying plate,
Nonuniformity of gas flow on the substrate due to uneven distribution of exhaust ports can be minimized, and uniform film formation can be performed even with a compact apparatus.

Further, an outer rectifying plate may be provided between the rectifying plate and the inner wall of the film-forming chamber, the outer rectifying plate forming a pair with the rectifying plate to form a reaction gas exhaust passage.
The straightening plate and the outer straightening plate may both be easily detachable.

[0010] A second annular plate may be provided above the first annular plate and forming a slit-shaped opening extending over the entire circumference so as to cover an upper portion of the annular flow path. The first annular plate may be formed to extend from the current plate. The width of the slit-shaped opening may be narrow at a position corresponding to the exhaust port, and may be increased as the distance from the exhaust port increases. The exhaust port may be one place.

A ring-shaped adjusting plate may be provided on the second annular plate to adjust the width of the slit opening to make the exhaust flow uniform. Further, at least a portion of the outer rectifying plate facing the space between the gas ejection head and the substrate holding portion may have a shape that is obliquely upward and convex. Further, the material of each current plate may be formed of quartz or a metal such as stainless steel or aluminum.

[0012] The current plate may be provided on an outer periphery of a side surface of a cylindrical wall provided around a side surface of the substrate holding member. The cylindrical wall may be provided with temperature control means for controlling the cylindrical wall to a predetermined temperature. The temperature control means may include a medium flow path formed in the cylindrical wall, and a heat medium supply means for supplying a medium controlled to a predetermined temperature outside.

According to another aspect of the present invention, a holding means for holding a substrate in an airtight film forming chamber having a substantially cylindrical shape, and an elevating mechanism for moving the substrate holding means at least between a film forming position and a transfer position A mechanism, a gas injection head for injecting a source gas for film formation from the top of the film formation chamber toward the substrate, a substrate transfer port opened at a height corresponding to the transfer position on a side wall of the film formation chamber, and a film formation chamber. In a thin film vapor phase growth apparatus provided with an exhaust port opening at a height between the film forming position and the transport position of the side wall of the thin film, the exhaust port is formed substantially at one location, and This is a thin film vapor phase growth apparatus in which the center of the injection density of the film-forming source gas to be injected is eccentric in the direction horizontally opposite to the position of the exhaust port with respect to the center of the substrate.

[0014] The center of the nozzle region of the gas injection head may be eccentric with respect to the center of the substrate in a direction opposite to the position of the exhaust port. Further, a large number of nozzle holes of the gas ejection head may be distributed on a side opposite to a position of the exhaust port with respect to a center of the substrate.

The reactive gas injection nozzle may be provided with a temperature control means for controlling the temperature of the injection nozzle to a predetermined temperature by using a heat medium. The gas injection head may have a gas injection nozzle area larger than the diameter of the substrate.

[0016]

FIG. 1 shows a first embodiment of the present invention. In this thin-film vapor deposition apparatus, a substrate W is placed in a substantially cylindrical air-tight film-forming chamber 10. A substrate holder 12 to be held, and an elevating mechanism 14 for elevating the substrate holder 12 at least between a film forming position (upper limit) and a transfer position (lower limit).
A gas injection head 16 for injecting a film forming material gas from the top of the film forming chamber 10 toward the substrate W;
Substrate transfer port 20 opening at a height corresponding to the transfer position 8
And an exhaust port 22 which is opened at a height between the film forming position and the transfer position on the side wall 18 of the film forming chamber 10. The exhaust port 22 and the substrate transfer port 20 are respectively provided at predetermined positions in the circumferential direction.

The substrate holder 12 has a disk-shaped susceptor 24 having a heater (heating means, not shown) therein, and a column 26 for connecting the susceptor 24 to the lifting mechanism 14. At the outer edge of the substrate of the susceptor 24, an annular deposition-preventing plate 28 having an L-shaped cross section for preventing adhesion due to the reaction is attached. The gas injection head 16 has a disk-shaped nozzle plate 32 slightly larger than the substrate W. The nozzle plate 32 has a plurality of nozzle holes 30 in a nozzle region 33 excluding a peripheral portion.
Are evenly distributed. Also, in this example, a jacket (temperature control means) for maintaining a mixed space of the source gas and the reaction gas (for example, oxidizing gas) therein and maintaining the nozzle hole 30 and the mixed space at a predetermined temperature by a heating medium. 34 are provided.

The film forming chamber 10 includes a cylindrical side wall 18, a bottom plate 36 having an opening for mounting the substrate lifting mechanism 14 in the center, a gas injection head 16 also serving as a top plate, and the side wall 18. An O-ring 40 and a bellows 42, which are seal members, are arranged at necessary places in a gas-tight manner from a taper block 38 forming a taper portion between the ejection heads 16, and a gate (not shown) is provided at the transfer port 20. I have. In this example, no heat medium flow path as a temperature control means is formed in the side wall 18 or the bottom plate 36.

In the film forming chamber 10, two flow regulating plates 44 for forming a flow path for guiding the reacted gas to the exhaust port 22,
46 are attached. That is, the inner current plate 44
Is a cylindrical plate 48 surrounding the elevating path of the substrate holder 12.
And the film forming chamber 1 at a height between the exhaust port 22 and the substrate transfer port 20.
A slit-shaped opening 5 that extends over the entire circumference between the first annular plate 50 that partitions the inner space up and down and the outer rectifying plate 46.
2 to form an annular flow path P ₁ for guiding the reacted gas to the exhaust port 22. The outer rectifying plate 46 is connected to the inner rectifying plate 44 and the film forming chamber 1.
0 is formed along the inner wall with the inner wall of
Exhaust flow path P that leads reaction gas to exhaust port 22 in pairs with
_Make up _two .

The slit-shaped opening 52 has one exhaust port 22.
In order to prevent the gas from drifting in the circumferential direction due to the number of the holes, the gap is formed so as to be closer to the exhaust port 22. Therefore, the gap d on the exhaust port 22 side
₁ is the minimum, the opposite gap d ₂ is the biggest this.
The upper end of the inner straightening plate 44 extends inward, and
8, the gap between the susceptor 24 and the susceptor 24 is reduced. The inner rectifying plate 44 and the outer rectifying plate 46 are mounted on and mounted on an annular projection 56 formed on the inner surface of the side wall 18 of the film forming chamber 10. Therefore, by removing the gas jet head 16 and the tapered block 38 at the top, the gas jet head 16 can be lifted and easily removed from the film forming chamber 10 or replaced.

The operation of the thin-film vapor deposition apparatus configured as described above will be described. The susceptor 24 is placed at a transfer position indicated by a two-dot chain line in FIG. 1, a substrate W is placed on the susceptor 24 by a robot hand (not shown) through the substrate transfer port 20, and the substrate W is raised to a film forming position shown in FIG. .
The substrate W is heated to a film forming temperature by the susceptor 24, and a mixed gas of a source gas and a reactive gas is injected from the gas injection head 16 maintained at a predetermined temperature by a heat medium.

The injected source gas and the reactive gas react on the substrate W to form a film, and the reacted gas flows radially on the substrate W and is formed between the inner rectifying plate 44 and the outer rectifying plate 46. flows into the exhaust passage P _2, further slit opening 52
And flows into the annular flow path P ₁ through the exhaust port 22. Here, the gap between the slit-shaped opening portions 52 is
2, a uniform radial gas flow is generated at various positions in the circumferential direction even if only one exhaust port 22 is provided, and therefore, uniform film formation without unevenness in the circumferential direction. Is made.

In this thin film vapor phase growth apparatus, the flow path of the reaction gas is limited by the inner rectifying plate 44, and the susceptor 2
4 or the lowering mechanism 14 below the film forming chamber 10. Accordingly, adhesion at these locations and contamination resulting therefrom are prevented. When the raw material components or the reaction products adhere to the rectifying plates 44 and 46, the gas injection head 16 and the tapered block 38 at the top of the film forming chamber 10 are opened, and the rectifying plates 44 and 46 are lifted, and replacement is performed. Thus, the film forming process can be continued. FIG. 2 is an example having the same configuration as that of FIG. 1 and not using the outer rectifying plate 46.

FIG. 3 shows a thin film vapor phase growth apparatus according to a second embodiment of the present invention. In this embodiment,
The second annular plate 54 itself of the inner current plate 44 is the outer current plate 4
6 is formed so as to form a gap having a uniform width in the circumferential direction between the second annular plate 54 and the exhaust port 22.
An annular adjustment plate 58 is eccentrically mounted such that the gap on the side is d ₁ and the gap on the opposite side is d ₂ . By shifting the position of the adjustment plate 58 or changing the shape of the adjustment plate 58, adjustment can be performed so as to form a uniform gas flow according to the film forming conditions. Further, in this embodiment, a cylindrical heat insulating wall 60 is formed between the inner rectifying plate 44 and the susceptor 24 to prevent a rise in the temperature of the rectifying plates 44 and 46 due to heat radiation from the susceptor 24. I have.

FIG. 4 shows another embodiment of the present invention. In this embodiment, a flow path 62 for flowing a heat medium such as oil is formed inside a heat insulating wall 60. In this, a heat medium supply pipe 64 for supplying a heat medium of a predetermined temperature from an external supply means and a return pipe are provided in communication with the side wall 18 of the film forming chamber 10. In this embodiment, since the radiant heat received from the holding member is absorbed by the heat medium, the function of suppressing the temperature rise of the side walls 18 of the rectifying plates 44 and 46 is higher.

FIG. 5 shows another embodiment of the present invention, in which a substrate W held by a susceptor 24 is shown.
The center of the nozzle area 33 of the nozzle board 32 of the gas injection head 16 is eccentric to the side opposite to the exhaust port 22 by e ₁ with respect to the center of the gas injection head 16. This may be applied to any of the devices of FIGS. In the case of FIG. 5A, the nozzle region 33 has a diameter R larger than the diameter r of the substrate W, and in the case of FIG. 5B, the nozzle region 33 has an ellipse having a semicircle of a diameter R separated by e _2. Is formed. The amount of displacement e ₁ , e ₂ is
To compensate for the uneven gas flow due to uneven distribution of
Set according to the conditions. In each case, the substrate W is arranged so as to be within the projection plane of the nozzle region 33.

FIG. 6 (a) shows still another embodiment of the present invention.
The distribution of the nozzle holes 30 in the nozzle region 33 is changed between the exhaust port 22 side and the opposite side. That is, since the exhaust port 22 of the film forming chamber 10 is located at one location, a flow toward the exhaust port 22 is generated on the substrate W. Therefore, if the distribution is symmetric, the gas flow density in a region near the exhaust port 22 is reduced. 22 will be larger than the opposite side. Therefore, in order to make this uniform, the gas injection amount on the opposite side of the exhaust port 22 is set to be larger than that on the exhaust port 22 side. This may also be applied to any of the devices of FIGS.

FIG. 6B shows still another embodiment of the present invention.
Is changed on the side of the exhaust port 22 and on the opposite side. That is, the nozzle region 33 of this embodiment, the exhaust port 22 side has a radius R ₁ slightly larger than the radius r of the substrate W, larger radius R than the radius R ₁ at the exhaust port 22 side opposite It is formed with _two . This is for increasing the gas density on the side opposite to the exhaust port 22 as in the previous embodiment, and may be applied to any of the apparatuses shown in FIGS.

[0029]

As described above, according to the present invention, it is possible to minimize the non-uniformity of the gas flow due to the uneven distribution of the exhaust port, and to achieve a compact structure.
It is possible to provide a thin film vapor phase growth apparatus capable of stably performing a uniform and high-quality film formation process on a substrate.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a thin-film vapor deposition apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a modification of the first embodiment of the present invention.

FIG. 3 is a sectional view showing a thin-film vapor deposition apparatus according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a thin-film vapor deposition apparatus according to another embodiment of the present invention.

FIG. 5 is a diagram showing a positional relationship between a gas injection head and a substrate in a thin film vapor phase growth apparatus according to another embodiment of the present invention.

FIG. 6 is a view showing a gas injection head of a thin film vapor phase growth apparatus according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Film-forming chamber 12 Substrate holder 14 Substrate raising / lowering mechanism 16 Gas injection head 18 Side wall 20 Substrate carrying port 22 Exhaust port 24 Susceptor 26 Support 28 Deposition plate 30 Nozzle hole 32 Nozzle board 44 Inner rectifying plate 46 Outer rectifying plate 48 Cylindrical plate 50 first annular plate 52 slit opening 54 the second annular plate 56 an annular projection 58 adjustment plate 60 insulating wall 62 passage 64 heat medium supply pipe P ₁ annular passage P ₂ exhaust passage W substrate d _1, d ₂ a gap r, R _1, R ₂ diameter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Shinozaki 11-1, Haneda Asahimachi, Ota-ku, Tokyo Inside the Ebara Works Co., Ltd. (72) Inventor Kuniaki Horie 11-1, Haneda Asahi-cho, Ota-ku, Tokyo Inside Ebara Works (72) Inventor Hiroyuki Ueyama 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. (72) Takeshi Murakami 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside Ebara Works Co., Ltd.

Claims (5)

[Claims] 1. A substrate holding means for holding a substrate in an airtight film forming chamber, an elevating mechanism for elevating the substrate holding means between at least a film forming position and a transfer position, and a film forming material gas directed toward the substrate. A gas ejection head that injects a gas, a substrate transfer port that opens at a height corresponding to the transfer position on the side wall of the film formation chamber, and an opening at a height between the film formation position and the transfer position on the side wall of the film formation chamber. In the thin film vapor phase growth apparatus provided with an exhaust port to perform, a rectifying plate for adjusting the flow of the reacted gas is provided in the film forming chamber, and the rectifying plate is a cylinder surrounding an elevating path of the substrate holding unit. A thin-film vapor phase growth apparatus comprising: a plate-shaped plate; and a first annular plate that vertically divides a film formation chamber space at a height between the exhaust port and the substrate transfer port. 2. The method according to claim 1, wherein the exhaust port is provided at one place, and an annular flow path that guides the reacted gas in the film forming chamber to the exhaust port is formed by the rectifying plate. The thin film vapor deposition apparatus according to the above. 3. An external rectifying plate between the rectifying plate and the inner wall of the film formation chamber, the outer rectifying plate forming a pair with the rectifying plate to form a reaction gas exhaust passage. 2. The thin-film vapor deposition apparatus according to 1. 4. The thin-film vapor deposition apparatus according to claim 1, wherein the rectifying plate is provided on an outer periphery of a side surface of a cylindrical wall provided around a side surface of the substrate holding member. 5. A film holding chamber for holding a substrate in an airtight film forming chamber having a substantially cylindrical shape as a whole, an elevating mechanism for moving the substrate holding means up and down at least between a film forming position and a transfer position, and a film forming chamber. A gas injection head for injecting a source gas for film formation from the top of the substrate toward the substrate, a substrate transfer port opening at a height corresponding to the transfer position on the side wall of the film formation chamber, and the film formation on the side wall of the film formation chamber. In a thin film vapor phase growth apparatus provided with an exhaust port opened at a height between a position and a transfer position, the exhaust port is formed substantially at one position, and a film forming material injected from the gas injection head is formed. A thin-film vapor deposition apparatus wherein the center of the gas injection density is eccentric in a direction horizontally opposite to the position of the exhaust port with respect to the center of the substrate.