JPH07100862B2 - Barrel type vapor phase growth equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a barrel-type vapor phase growth apparatus for forming a thin film on a substrate.

[Conventional technology]

Conventionally, a barrel type vapor phase growth apparatus has been used as an apparatus for processing a large number of substrates at once. FIG. 4 shows an example of a conventional device, in which a gas introduction pipe 1 is provided at the top and a gas discharge pipe is provided at the lower side.
A holding base 6 supported on the upper end of a vertically movable and rotatable shaft member 5 is provided inside the cap-shaped reaction tube 4 in which the RF coil 3 is wound around the outer circumference of which the RF coil 3 is wound. The flow channel 7 is mounted on the.

The holding table 6 is used for holding and heating the substrate, and has a substrate mounting groove 6a provided on the side surface of a polygonal pyramid-shaped body made of carbon. The flow channel 7 is used for rectifying and preheating the vapor growth gas introduced from above, and is a warhead-like cover having a smooth surface.

In the conventional device, after mounting the board in the board mounting groove 6a, RF
The coil 3 is induction-heated with the holding table 6 to hold the substrate at a predetermined temperature, and the vapor growth gas is introduced from the gas introduction pipe 1 to form a thin film on the substrate. That is, the vapor growth gas introduced into the reaction tube 4 is rectified by the flow channel 7 and smoothly flows downward, and the heating portion near the lower end of the flow channel 7 is heated to a high temperature by heat conduction from the holding table 6. Is preheated to start the thermal decomposition reaction, and the reaction product is deposited on the substrate to form a thin film.

[Problems to be solved by the invention]

However, in the conventional device described above, a steep interface cannot be obtained when forming multiple thin films on a substrate. This is, for example, A gas, B
This is because if two kinds of vapor phase growth gases of gas are alternately introduced into the reaction tube, these A gas and B gas will be partially mixed in the reaction tube. Therefore, conventionally, the purge gas is caused to flow between the A gas and the B gas to prevent the mixing of the gases, but this causes a problem that the processing time becomes long and the productivity is lowered.

Further, in the conventional apparatus, the thin film formation is improved by the preheating, but the preheating causes the deposit 8 to adhere to the vicinity of the lower end of the flow channel 7, and the amount of the deposit 8 gradually increases and the surface of the substrate is gradually increased. It peels off and falls on the surface, degrading the quality of the thin film. Therefore, it is necessary to remove and clean the flow channel 7 as appropriate, but as described above, since the flow channel 7 does not have a protrusion on the surface in order to perform the rectifying action, it is difficult to attach and detach, and maintenance is not easy. .

As a result of various studies made by the inventor in view of the above-mentioned inconvenience, in the conventional apparatus, when a gas is introduced into the reaction tube 4, a stagnation portion 9 is formed above the reaction tube 4 and is in contact with the stagnation portion 9. It has been found that the gas flows because the gas flows.

An object of the present invention is to provide a barrel type vapor phase growth apparatus capable of forming multiple thin films having steep interfaces based on the above findings.

[Means for solving problems]

Therefore, in order to achieve the above object, the present invention provides a barrel-type vapor phase in which a holding base and a flow channel mounted on the holding base are provided inside a cap-shaped reaction pipe having a gas introduction pipe and a gas discharge pipe. In the growth apparatus, the flow channel is formed in a cylindrical shape, and at least two places are provided on the side surface of the reaction tube at a position corresponding to the vicinity of the upper end of the cylindrical flow channel when the holding table is set at a predetermined position in the reaction tube. It is characterized in that the gas introduction pipe is provided toward the central axis of the flow channel.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, and the same components as those in FIG. 4 are designated by the same symbols.

FIG. 1 is a sectional view of the device of the present invention showing the holding base and the flow channel on the outer surface, and FIG. 2 is a sectional view taken along line II-II of FIG.

The device of the present invention is different from the conventional device of FIG. 4 in the shape of the flow channel and the arrangement of the gas introduction pipes. That is, the flow channel 10 of the device of the present invention has a cylindrical shape with an appropriate length,
The upper end has a collar portion 10a. Reference numeral 11 is an inverted U-shaped projection for attachment / detachment provided at an arbitrary position on the upper end of the flow channel 10.

Next, the gas introduction tube 12 is provided on the side surface of the reaction tube 4 at a position corresponding to the vicinity of the upper end of the cylindrical flow channel 10 when the holding table 6 is set at a predetermined position in the reaction tube 4 as shown in the figure. The mounting direction is the central direction of the cylindrical flow channel 10. At least two gas inlet tubes 12
It is necessary to provide it at more places, but it may be provided at more places, and it is desirable that the places be provided at equal intervals along the outer circumference of the reaction tube 4.

Next, an operation of forming a thin film on a substrate using the apparatus of the present invention configured as described above was performed in the same manner as above. As a result, it was possible to form a thin film that was as good as or better than the conventional device shown in FIG. This is rectified in the process in which the vapor growth gas ejected from the gas introduction pipe 12 circulates around the body of the cylindrical flow channel 10 and diffuses uniformly, and flows down the body of a sufficient length. Further, it is possible to obtain a suitable thin film formation state by preheating in a high temperature portion near the lower end of the cylindrical flow channel 10. In addition, a steep interface was obtained without using a purge gas in the formation of multiple thin films. This is because the free space above the cylindrical flow channel 10 is the bag, and the gas introduction pipe 12
Since it is divided into the upper and lower sides of the flow path of the vapor growth gas introduced from the above, the ratio of the vapor growth gas in contact with the free space is extremely small in the conventional device as compared with the device. The apparatus of the present invention is used in the reaction tube 4 at the same time when the vapor growth gas is introduced.
If a small amount of hydrogen or the like is introduced as a purge gas from the top of the, the free space is filled with the purge gas, so that the effect on the vapor phase growth gas introduced from the gas introduction pipe 12 is further reduced, and a steeper interface is obtained. It is possible to form various thin films having Further, the flow channel 10 may be simply cylindrical and not have the flange portion 10a, but it is preferable to have the flange portion 10a when forming various thin films. In the apparatus of the present invention, as in the case of the conventional apparatus, a deposit 8 is generated in the vicinity of the lower end of the cylindrical flow channel 10 due to the preheating. This deposit 8 can be removed and cleaned by utilizing the inverted U-shaped projection 11. good.

Next, another embodiment will be described with reference to FIG. FIG. 3 is a sectional view showing the cylindrical flow channel 10 and the holding table 5 on the outer surface.

In this embodiment, the reaction tube 4 is provided with a gas introduction tube so that an upper lid 41 is provided above the reaction tube 4.
It is divided into a main body 42 and a detachable body, and
A front chamber 43 connected to the upper side of the main body 42 and containing the upper lid 41 therein.
Is provided. Furthermore, 44 is a purge pipe, and one end is an upper lid.
It is connected to the top of 41, and the other end is connected to a vertical movement mechanism 45 such as a piston, slidably penetrating the ceiling of the front chamber 43. Reference numeral 46 is a coil tube that is formed into a coil shape so as to follow the vertical movement of the purge tube 44.

With this device configured as described above, after forming a thin film on the substrate,
The upper lid 41 is moved up and the shaft member 5 is moved up to move the holding table 6 into the front chamber 43 to exchange the processed substrate and the unprocessed substrate.
As a result, it is possible to prevent the adverse effects of the deposit 47 adhering to the lower side portion of the reaction tube 4. That is, when the thin film is formed, not only the deposit 9 adheres to the vicinity of the lower end of the cylindrical flow channel 10 but also the deposit 47 adheres to the lower side portion of the reaction tube 4, both of which are separated and dropped. For this reason, in a general vapor phase growth apparatus, since the antechamber is arranged below the reaction tube, the holder is lowered after the thin film is formed.
The quality of the board had deteriorated due to the drop of 47. The apparatus of this embodiment has a structure suitable for forming multiple thin films and solves the inconvenience caused by the fall of the deposit 47. Although the purge pipe 44 is used in the present embodiment, it may be a simple pipe or rod when the purge gas is not required, and the coil pipe 46 is not necessary at this time.

〔The invention's effect〕

In the apparatus of the present invention, as described above, the flow channel is formed into a cylindrical shape, and the gas introduction tube is provided on the side surface of the reaction tube so that the vapor growth gas is blown toward the center of the cylindrical flow channel. Can form a thin film equivalent to
Particularly in the formation of multiple thin films, the vapor growth gas introduced from the side surface of the reaction tube is not easily affected by the free space above the cylindrical flow channel, so that different types of vapor growth gas can be used without a purge gas in the middle. Even if they are successively introduced into the reaction tube, a multiple thin film having a steep interface can be obtained, so that the amount of purge gas used and the processing time can be reduced, and the productivity can be greatly improved as compared with the conventional case. Further, in the device of the present invention, since the top portion of the cylindrical flow channel has no special action, a protrusion for attachment / detachment can be provided here, and the maintenance of the flow channel can be facilitated.

Further, when the reaction tube is configured to be detachably attached to the upper lid and the main body above the gas introduction tube and the front chamber is provided above the reaction tube, deposits attached to the lower side portion of the reaction tube It is possible to prevent an adverse effect due to.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment of the device of the present invention, and FIG.
1 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional front view showing another embodiment of the device of the present invention, and FIG. 4 is a sectional front view showing an example of a conventional device. 2 ... Gas discharge pipe, 3 ... RF coil, 4 ... Reaction pipe, 5 ... Shaft member, 6 ... Holding base, 10 ... Flow channel, 12 ... Gas introduction pipe, 41 ... Reaction pipe 4 upper lid, 42 ... Reaction pipe 4 Body of the 43 ... front chamber

Claims (2)

[Claims] 1. A barrel type vapor phase growth apparatus in which a holding base and a flow channel mounted on the holding base are provided inside a cap-shaped reaction pipe having a gas introduction pipe and a gas discharge pipe. Is formed into a cylindrical shape,
At least two gas introduction pipes were provided on the side surface of the reaction tube at a position corresponding to the vicinity of the upper end of the cylindrical flow channel when the holding table was set at a predetermined position in the reaction tube toward the central axis of the flow channel. A barrel type vapor phase growth apparatus characterized in that 2. The reaction tube having a side gas introduction tube is configured to be attachable / detachable to / from the upper lid and the body above the gas introduction tube installation position, and the reaction tube is continuously provided above the body of the reaction tube. The barrel type vapor phase growth apparatus according to claim 1, further comprising a front chamber having a built-in upper lid.