JPH1143773A - Thin coating vapor growth device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin film vapor growth device evading the decomposition of coating forming raw material at high temps. on the wall face in a film forming chamber and capable of stably executing treatment for forming uniform film high in quality. SOLUTION: This thin film vapor growth device is the one in which an airtight film forming chamber 10 the whole body of which is approximately cylindrical in shape is provided with a holding and heating means 12 holding and heating a substrate, an elevating mechanism 14 elevating and lowering the holding and heating means 12 at least between the film forming position and the transporting position, a gas injection head 16 injecting a film forming gaseous starting material toward the substrate from the tip of the film forming chamber 10, a substrate transporting port 20 opened at the height corresponding to the transporting position of the side wall 18 of the film forming chamber 10 and an exhaust port 22 opened at the height between the film forming position of the side wall 18 of the film forming chamber 10 and the transporting position. In this case, it has a heat insulating member 44 with an approximately cylindrical shape surrounding the circumference of the substrate holding and heating means 12 on the film forming position.

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. Also, metal oxide thin film materials such as barium titanate (BaTiO ₃ ), strontium titanate (SrTiO ₃ ) having a dielectric constant of about 300, or barium strontium titanate which is a mixture thereof are considered to be 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 shower 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 jetting thin film vapor deposition apparatus is used.

[0004]

The characteristics of the above-mentioned film forming raw materials are that the temperature range of the gaseous phase after vaporization is narrow, and condenses when the temperature falls below the vaporization temperature and decomposes when the temperature rises. Can be On the other hand, the present inventors have proposed a method of forming a film while maintaining and controlling the inner wall surface of the reaction chamber at a predetermined temperature (substantially the vaporization temperature) (Japanese Patent Laid-Open No. 9-2896). Although it was found that the generation of substances can be effectively suppressed, it cannot be reduced to zero at all, and it has been found that fine products are generated and adhered to a considerable extent.

[0005] Therefore, as a result of a thermal analysis of the above-mentioned raw materials, there is no clear and complete temperature range in which three types of liquid raw materials such as BST and SBT can simultaneously maintain a gaseous state. Was found to condense or decompose. It was also found that the decomposed raw material was difficult to clean, while the condensed raw material was relatively easy to clean.
Thus, a practical solution to the above problem was achieved by adopting a method of avoiding decomposition at a high temperature while allowing partial coagulation.

In view of the above, the present invention has been made in consideration of the above circumstances, and it is intended to prevent the decomposition of a film forming material at a high temperature on a wall surface in a film forming chamber and to stably perform a uniform and high quality film forming process on a substrate. It is intended to provide a growth device.

[0007]

According to a first aspect of the present invention, a holding and heating means for holding and heating a substrate in an airtight film forming chamber having a substantially cylindrical shape as a whole, and at least the holding and heating means for forming a film, A lifting mechanism for raising and lowering between a position and a transfer position, a gas injection head for injecting a film forming material gas from the top of the film formation chamber toward the substrate, and a height corresponding to the transfer position on the side wall of the film formation chamber. In a thin film vapor deposition apparatus provided with a substrate transfer port that opens and an exhaust port that opens at a height between the film formation position and the transfer position on the side wall of the film formation chamber, the substrate holding and heating at the film formation position is provided. A thin-film vapor deposition apparatus having a substantially cylindrical heat insulating member surrounding the means.

Accordingly, the heat insulating member suppresses the radiation of heat from the holding and heating means, and prevents the inner wall and the like of the film forming chamber from being heated to a temperature higher than the decomposition temperature of the raw material. Therefore, the raw material is prevented from decomposing and adhering at these locations. When the raw material is condensed in these places, it is washed and removed by a predetermined method, and the operation of the apparatus is continued. It is preferable that the heat insulating member is formed of a heat insulating material such as quartz, stainless steel, and ceramics.

The invention according to claim 2 is characterized in that the heat insulating member is provided with temperature control means for controlling itself to a predetermined temperature. Device. The temperature control means is configured to have, for example, a medium flow path formed in the heat insulating member, and a heat medium supply means for supplying a medium controlled to a predetermined temperature outside.

The invention according to claim 3 is the thin film vapor phase growth apparatus according to claim 1, wherein the heat insulating member is detachably provided in the film forming chamber. According to a fourth aspect of the present invention, there is provided the thin-film vapor deposition apparatus according to the first aspect, further comprising a cooling unit configured to cool an outer wall of the film forming chamber to a predetermined temperature or less. .
It is preferable that a support member for supporting the heat insulating member is provided below the exhaust port and above the transfer port in the film forming chamber.

[0011]

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 holding / heating means 12 for holding and heating; an elevating mechanism 14 for raising / lowering the substrate holding / heating means 12 at least between a film forming position (upper limit) and a transport position (lower limit); A gas injection head 16 for injecting a film forming source gas toward
A substrate transfer port 20 opening at a height corresponding to the transfer position of the side wall 18 of the film formation chamber 10; an exhaust port 22 opening at a height between the film formation position and the transfer position of the side wall 18 of the film formation chamber 10; Is provided. The exhaust port 22 and the substrate transfer port 20 are respectively provided at predetermined positions in the circumferential direction.

The substrate holding and heating means 12 has a disk-shaped susceptor 24 having a heater (heating means, not shown) therein.
And a column 26 for connecting this to the lifting mechanism 14. At the outer edge of the susceptor 24, an annular deposition prevention plate 28 for preventing adhesion due to the reaction is attached. The gas injection head 16 has a nozzle plate 32 having a disk shape slightly larger than the substrate W and in which a plurality of nozzle holes 30 are uniformly distributed. In this example, a source gas and a reaction gas (for example, oxidizing gas) are provided inside. ), And a jacket (temperature control means) 34 for maintaining the nozzle holes 30 and the mixing space at a predetermined temperature by a heat medium.

The film forming chamber 10 has 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 a space between the side wall 18 and the head. An O-ring 40 and a bellows 42, which are sealing members, are arranged at necessary places, and a gate (not shown) is provided at the transfer port 20. 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, a cylindrical heat insulating member 44 is provided so as to surround the elevating path of the substrate holding and heating means 12. This heat insulating member is integrally formed with a ring-shaped plate 46 that is attached to the lower part thereof by a heat insulating material such as quartz, stainless steel, or ceramics. And
It is mounted on an annular projection 48 formed on the inner surface of the side wall 18 of the film forming chamber 10 below the exhaust port and above the transfer port. Accordingly, by removing the top shower head 16 and the tapered block 38, they 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 through the substrate transfer port 20, and the susceptor 24 is raised by the elevating mechanism 14 to the film formation 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 shower head 16 maintained at a predetermined temperature by a heat medium.

The injected raw material 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 by the side wall 18 of the film forming chamber 10 and the heat insulating member 44. The gas flows into the exhaust passage P and is exhausted from the exhaust port 22.
Here, the flow path of the reaction gas is limited by the heat insulating member 44 and the annular plate 46, and it is difficult for the reaction gas to flow to the back side of the susceptor 24, the elevating mechanism 14 below the film forming chamber 10, and the like. And the contamination caused by it.

During the film forming reaction, the heat insulating member 44 suppresses the radiation of heat from the holding and heating means 12, and
And the like are prevented from being heated above the decomposition temperature of the raw material. Therefore, the raw material is prevented from decomposing and adhering at these locations. When the raw material condenses at these locations, the shower head 16 or the tapered block 3 at the top of the film forming chamber 10
8 is removed, these portions are removed by washing in a predetermined manner, and the operation of the apparatus is continued.

FIG. 2 shows a thin film vapor phase growth apparatus according to a second embodiment of the present invention. In this embodiment,
The heat insulating member 44 is formed in a simple cylindrical shape, and the side wall 18 of the film forming chamber 10 is formed.
It is detachably attached to an annular groove 52 of a support plate 50 provided on the inner surface. In this embodiment, since the shape is simple and compact, not only the manufacturing of the heat insulating member 44 is facilitated, but also the removal and replacement are further facilitated. In particular, this is convenient when the material of the heat insulating member 44 is changed according to the film forming conditions.

FIG. 3 shows another embodiment of the present invention. In this embodiment, a flow path 54 for flowing a heat medium such as oil is formed inside a heat insulating member 44. A heat medium supply pipe 56 for supplying a heat medium at 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 heat holding member is absorbed by the heat medium, the function of suppressing the temperature rise of the side wall 18 of the film forming chamber 10 is higher.

FIG. 4 shows still another embodiment of the present invention, in which a side wall 18 and a lifting flange 6 are shown.
A jacket 59 is also formed on the elevating flange 60 fixed to the jacket 58 of the side wall 18 and the bottom plate 36 constituting the cooling means, in order to minimize the heating of the heating means 12 by the holding and heating means 12. . Accordingly, in addition to the heat shielding function of the heat insulating member 44, a function of more reliably maintaining the temperature of the inner wall of the film forming chamber 10 at a temperature equal to or lower than the film forming reaction is secured. Furthermore, it also contributes to the improvement of the durability of the seal parts, the safety of workers, and the like.

[0021]

As described above, according to the present invention, the heat insulating member suppresses the radiation of heat from the holding and heating means,
It is possible to prevent the inner wall and the like of the deposition chamber from being heated to a temperature higher than the decomposition temperature of the raw material. Therefore, the raw material is prevented from decomposing and adhering at these locations, and a uniform and high quality film forming process can be stably performed on the 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 sectional view showing a thin-film vapor deposition apparatus according to a second embodiment of the present invention.

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

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 film forming chamber 12 susceptor (substrate holding and heating means) 14 elevating mechanism 16 gas injection head 18 side wall 20 substrate transfer port 22 exhaust port 30 injection nozzle 32 nozzle plate 44 heat insulating member 59 jacket 60 elevating flange P flow path M mixing space W substrate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Isamu Tsukamoto 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation (72) Inventor Mitsunao Shibasaki 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Stock (72) Inventor Hiroyuki Ueyama 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside the Ebara Corporation (72) Inventor Takeshi Murakami 11-1 Haneda Asahi-cho, Ota-ku, Tokyo Inside Ebara Corporation

Claims (4)

[Claims] 1. A holding and heating means for holding and heating a substrate in an airtight film forming chamber having a substantially cylindrical shape as a whole, an elevating mechanism for raising and lowering the holding and heating means at least between a film forming position and a transfer position, A gas injection head for injecting a film-forming source gas toward the substrate from the top of the film-forming chamber, a substrate transfer port opening at a height corresponding to the transfer position on the side wall of the film-forming chamber, and a side wall of the film-forming chamber. A thin-film vapor deposition apparatus provided with an exhaust port opening at a height between the film-forming position and the transfer position, comprising a substantially cylindrical heat-insulating member surrounding the periphery of the substrate holding and heating means at the film-forming position. A thin film vapor phase growth apparatus characterized by the above-mentioned. 2. The thin film vapor phase growth apparatus according to claim 1, wherein said heat insulating member is provided with a temperature control means for controlling itself to a predetermined temperature. 3. The thin film vapor deposition apparatus according to claim 1, wherein the heat insulating member is detachably provided in the film forming chamber. 4. The thin film vapor phase growth apparatus according to claim 1, further comprising cooling means for cooling an outer wall of said film forming chamber to a predetermined temperature or lower.