JPH10195661A - Vapor growth device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor growth device reduced in the sticking of a reaction product to a shower head (gaseous starting material injection nozzle) as possible and facilitated in the cleaning of the inside of a film forming section. SOLUTION: In this vapor growth device provided with a heating means 4 inside, a substrate holding means 3 for holding a substrate W and the gaseous starting material injection nozzle 5 for ejecting a film forming gaseous starting material toward the substrate on the substrate holding means, a flat plate-like radiant heat cut-off device 10 having air permeability and heat insulating property is installed to face a gas injection surface of the gaseous starting material injection nozzle between the substrate and the gaseous starting material injection nozzle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase growth apparatus, and more particularly, to a thin film vapor phase growth apparatus for growing a high dielectric or ferroelectric thin film such as barium / strontium titanate on a substrate. To the optimal internal structure of the deposition chamber.

[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. Metal oxide thin film materials such as barium titanate (BaTiO ₃ ) having a dielectric constant of about 300, strontium titanate (SrTiO ₃ ), or a mixture thereof, such as barium strontium titanate, are promising.

When such a metal oxide thin film is vapor-phase grown on a substrate, one or a plurality of organometallic compound gas raw materials and an oxygen-containing gas are mixed, and the mixture is heated on a substrate heated to a certain temperature. We aim to inject.

That is, a substrate conveyed into the film forming chamber and placed on the substrate holding means is heated to a predetermined temperature by a heating means built in the substrate holding means or provided at a lower portion thereof. In general, a gas mixture of a gas source and an oxygen-containing gas is injected toward a substrate from a shower head (source gas injection nozzle) installed inside a film forming chamber.

When a thin film is grown on a substrate using the above-mentioned gaseous materials, a compound with a metal, for example, S
Intermediate products such as rO ₂ , SrCO ₃ , BaO ₂ , BaCO _3, or an organic metal compound as a raw material are generated and adhere to a mixed gas injection surface or the like of a shower head. When such adhesion occurs, for example, in a heat cycle when the apparatus is operated / stopped, the adhesion is peeled off due to a difference in thermal expansion coefficient between the adhesion and the shower head,
This leads to generation of particles and contamination of the substrate.

For this reason, there has been proposed an apparatus in which a coolant is circulated in a shower head and a cooling mechanism is provided in the shower head itself, thereby preventing adhesion to the shower head.

[0007]

However, even if a cooling mechanism is provided in the shower head itself as in the conventional example, radiant heat from a substrate or the like by a built-in heating means on the surface of the shower head, especially on the surface facing the substrate, can be prevented. It is said that the shower head cannot directly prevent the metal compound from adhering to the shower head because the shower head receives the temperature directly and generally has a considerable temperature difference between the temperature for keeping the mixed gas and the film forming temperature for the substrate. There was a problem.

[0008] When the deposits on the shower head are generated as described above, it is necessary to remove the deposits. To this end, it is necessary to remove the shower head from the inside of the film forming chamber. A gas supply line such as a source gas or an oxygen-containing gas is attached, and if a cooling mechanism is further provided, a refrigerant line and the like are attached, and the shower head itself is quite heavy, so that there is a problem that this cleaning work is considerably difficult. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to minimize the adhesion of a reaction product to a shower head (raw material gas injection nozzle) and to easily clean the inside of a film forming chamber. It is an object of the present invention to provide a vapor phase growth apparatus as described above.

[0010]

According to a first aspect of the present invention, there is provided a substrate holding means having a heating means therein and holding a substrate, and spraying a film forming material gas toward the substrate on the substrate holding means. In the vapor phase growth apparatus provided with a raw material gas injection nozzle, a substantially flat radiant heat shut-off device having air permeability and heat retaining property is provided between the substrate holding means and the raw material gas injection nozzle. A vapor phase epitaxy apparatus characterized in that the apparatus is installed opposite to the above.

According to the present invention, the radiant heat from the substrate holding means by the built-in heating means is cut off by the radiant heat cut-off device, so that the deposits are prevented from adhering to the material injection nozzle as much as possible. it can. In addition, by providing the radiant heat cutoff device with air permeability and heat retention, it is possible to prevent the diffusion of the source gas ejected from the source gas injection nozzle to the substrate or to prevent the temperature from decreasing. . The radiant heat shut-off device directly receives radiant heat from the substrate holding means and a large amount of deposits adhere to the surface.However, since the radiant heat shut-off device is a separate structure from the shower head, this removal is relatively easy. It can be done easily.

According to a second aspect of the present invention, the radiant heat shut-off device is installed inside the film forming chamber so as to be freely inserted and removed from the side of the film forming chamber or from above and below. It is a growth device. This makes it possible to extremely easily take out the radiant heat interrupting device to which the deposits have adhered from the film forming chamber and perform this cleaning.

According to a third aspect of the present invention, the radiant heat blocking device is constituted by a plurality of pipes extending substantially in parallel at a predetermined pitch and circulating a heating liquid medium therein. Is a vapor phase growth apparatus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The vapor phase growth apparatus of this embodiment is, for example, a method in which Ba, Sr, Ti or a compound thereof is used as a DPM compound, and a plurality of liquid raw materials in which these are dissolved in an organic solvent are mixed in advance, and then the mixed liquid is vaporized. While mixing the gas raw material generated by vaporization in the vessel and the oxygen-containing gas, the mixture is sprayed onto a substrate heated to a certain temperature, and a barium strontium titanate metal oxide thin film is vapor-phased on the substrate. Best to use for growing.

As shown in FIG. 1, a substrate holding means 3 is disposed in a film forming chamber 2 surrounded by a substantially cylindrical outer wall 1 so as to be able to move up and down. A substrate heater 4 is incorporated as a heating unit for heating the substrate W mounted and held on the upper surface of the substrate holding unit 3 to a film forming temperature.

On the other hand, located above the substrate holding means 3,
A shower head (source gas injection nozzle) 5 for injecting a film forming source gas is disposed, and a gas source having Ba, Sr, Ti, etc., an oxygen-containing gas and a gas source are provided from a number of gas injection ports 5 a provided in the shower head 5. Is injected toward the substrate W.

Thus, while the substrate W held on the substrate holding means 3 is heated to a predetermined temperature by the substrate heater 4, the mixed gas is jetted from the shower head 5 toward the substrate W, so that the surface of the substrate W A metal oxide thin film of barium strontium titanate is vapor-phase-grown, and an exhaust port 6 for exhausting gas after the reaction is provided below the film forming chamber 2.

Between the substrate holding means 3 and the shower head 5, a substantially flat radiant heat cutoff device 10 is installed so as to be substantially parallel to the gas ejection surface 5b of the shower head 5. An opening 1a is provided in the outer wall 1, and a radiant heat blocking device 10 is attached to a closing plate 11 that covers the opening 1a. The radiant heat blocking device 10 is formed to have a cross section smaller than that of the opening 1a. The radiation heat blocking device 10 can be pulled out of the film formation chamber 1 from the opening 1a via the plate 11.

Further, guide plates 12 are provided vertically on both sides of the lower surface of the shower head 5 parallel to the drawing direction of the radiant heat shielding device 10 to prevent the gas ejected from the shower head 5 from leaking to the side. ing.

The radiant heat shut-off device 10 has air permeability and heat retention, thereby preventing the gas ejected from the shower head 5 from diffusing into the substrate and preventing the temperature from lowering. It has become.

That is, in this embodiment, the radiant heat shut-off device 10 includes a plurality of thin pipes 14 arranged at a predetermined pitch between a pair of main pipes 13a and 13b arranged in parallel with each other as shown in FIG. Place them in parallel,
One main pipe 13a is connected to the heat medium supply pipe 15, and the other main pipe 13b is connected to the heat medium discharge pipe 16.

Thus, for example, oil (heated liquid medium) at 250 ° C. is supplied from the heat medium supply pipe 15 to the main pipe 1.
3a, the oil is branched from the main pipe 13a into a plurality of narrow pipes 14 and flows there. After being joined by the main pipe 13b, the oil is discharged from the discharge pipe 16 to have a heat retaining property. The gas flows through the gaps between the thin pipes 14 and has gas permeability.

As described above, even if a plurality of small pipes 14 are arranged above the substrate W, the gas diffuses uniformly and reaches the upper surface of the substrate W, so that a stripe pattern is formed on the substrate W. It will not stick.

In this embodiment, the thin pipe 14
While the substrate W held on the substrate holding means 3 is heated to a predetermined temperature by the substrate heater 4 in a state in which the heating oil is flowed in the inside, the mixed gas is jetted from the shower head 5 toward the substrate W so that the substrate W In this case, the radiant heat from the substrate W is cut off by the radiant heat cutoff device 10 so that the amount of the metal compound such as SrCO ₃ attached to the shower head 5 is drastically reduced. be able to.

In addition, as described above, the radiation heat cutoff device 1
Since No. 0 has air permeability and heat retention, diffusion of the raw material gas ejected from the shower head 5 to the substrate W is not hindered and the temperature does not decrease.

The radiant heat interrupter 10 directly receives the radiant heat from the substrate W, and a large amount of deposits adhere to the surface of the radiant heat interrupter. The radiant heat interrupter 10 can be easily removed by removing the radiant heat interrupter 10 from the film forming chamber 2. Can be.

As shown in FIG. 4, the thin pipe 14 is
The effect of preventing adhesion to the shower head 5 can be increased by arranging the stairs in a stepwise manner and in a staggered manner. Radiant heat from an oblique direction may directly reach the shower head 5 (see T in the figure).

Therefore, as shown in FIG.
Is located in the upper and lower stages, and at the bottom, the thin pipe 14
Is disposed at a position where the radiant heat directly reaching the shower head 5 shown in FIG. 4 is blocked, it is possible to almost completely prevent the radiant heat from reaching the shower head 5.

Incidentally, as shown in FIG.
The motor 0 may be driven to rotate by a motor M so that it can be inserted and removed vertically from the film forming chamber.

[0030]

As described above, according to the present invention, it is possible to prevent the source gas ejected from the source gas injection nozzle from diffusing to the substrate and to prevent the temperature from decreasing. The radiant heat from the substrate holding means by the heating means can be blocked by the radiant heat blocking device, and the adhesion of the deposit to the raw material injection nozzle can be prevented as much as possible. Moreover, the radiant heat shut-off device directly receives the radiant heat from the substrate holding means, and a large amount of deposits adhere to this surface. be able to.

Further, by installing the radiant heat shut-off device inside the film forming chamber so as to be freely inserted and removed from the side of the film forming chamber or from above and below, the radiant heat shut-off device to which the adhered substance adheres can be very easily removed from the film forming chamber. It can be taken out and maintenance such as cleaning can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of the present invention.

FIG. 2 is a plan view of the radiation heat cutoff device.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a diagram corresponding to FIG. 3, showing another embodiment.

FIG. 5 is a view corresponding to FIG. 3, showing still another embodiment.

FIG. 6 is a schematic sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 2 Film forming chamber 3 Substrate holding means 4 Substrate heater 5 Shower head (raw material gas injection nozzle) 5b Shower injection surface 10 Radiation heat cutoff device 13a, 13b Main pipe 14 Thin pipe

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuji Araki 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (3)

[Claims] 1. A vapor phase growth apparatus comprising: a substrate holding means having a heating means therein and holding a substrate; and a source gas injection nozzle for injecting a source gas for film formation toward the substrate on the substrate holding means. In the gas phase, a substantially flat radiant heat shut-off device having air permeability and heat retaining property is provided between the substrate holding means and the source gas injection nozzle, facing the gas injection surface of the source injection nozzle. Growth equipment. 2. The vapor phase growth apparatus according to claim 1, wherein the radiant heat cut-off device is installed inside the film formation chamber so as to be freely inserted and removed from a side or a vertical direction of the film formation chamber. 3. The vapor phase growth apparatus according to claim 1, wherein the radiant heat interrupting device is constituted by a plurality of pipes extending substantially in parallel at a predetermined pitch and circulating a heating liquid medium therein.