JP3440371B2 - Cleaning equipment for vapor phase growth equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus for a vapor phase growth apparatus, and more particularly to cleaning the inside of a reaction tube of a vapor phase growth apparatus for forming a semiconductor thin film on a substrate by using a source gas containing a phosphorus compound. A cleaning device suitable for.

[0002]

2. Description of the Related Art When forming a compound semiconductor thin film containing phosphorus such as indium phosphide on a substrate by MOCVD using a vapor phase growth apparatus, it did not contribute to thin film formation. The phosphorus compound as a raw material decomposes and adheres to the inner surface of the reaction tube as yellow phosphorus or falls to the lower part. This yellow phosphorus is a substance that is toxic and ignitable, so if you disassemble the vapor phase growth device to clean the inside of the reaction tube and remove the reaction tube and expose it to the atmosphere, deposits (including falling objects, (Similarly), there is a problem that yellow phosphorus in is abruptly reacted with oxygen in the air and ignites to generate poisonous gas, which is very dangerous. Further, the combustion of the yellow phosphorus may heat and evaporate other harmful deposits.

Further, when the yellow phosphorus burns when the reaction tube is removed, the air in the clean room in which the vapor phase growth apparatus is installed is polluted, so that the clean room has a long cleanness. There was also a problem that the next work could not be done in time.

Therefore, before disassembling the vapor phase growth apparatus, a gas containing oxygen is introduced into the reaction tube to oxidize the yellow phosphorus to change it into stable phosphorus oxide, or heat the reaction tube to convert the yellow phosphorus into yellow phosphorus. It has been proposed to change red phosphorus to red phosphorus (Japanese Patent Laid-Open No. 6-283429, Japanese Utility Model Laid-Open No. 4-1276).
42).

According to these methods, the work can be performed relatively safely as compared with the conventional method, but it is difficult to change the yellow phosphorus at the center of the deposit to phosphorus oxide or red phosphorus. When the deposit is thick, for example, when the deposit is separated from the inner surface of the reaction tube when the reaction tube is removed and cleaned, or when the deposit cracks, yellow phosphorus may be exposed and burned.

[0006] On the other hand, there is also a method in which the deposits in the reaction tube are removed by vacuum suction, and the suctioned gas is passed through, for example, water to prevent the combustion of yellow phosphorus. The suction nozzle used in this method has a small nozzle diameter so that substances in complicated shapes can be sufficiently sucked, but the wall surface in the vicinity of the suction nozzle is rubbed with a metal piece or the like to remove the adhered substances. While doing so, the suction operation is performed.

However, if the wall surface is rubbed with a metal piece or the like, it may easily exceed the ignition point (60 ° C.) of yellow phosphorus due to frictional heat, and yellow phosphorus may be ignited. At this time, if the suction by the suction nozzle is continued, a flow of the atmosphere is generated near the ignition part to promote combustion, which may be a very dangerous state. Moreover, even if the suction is stopped, the combustion itself continues until there is no active yellow phosphorus, so that toxic reactants and the like spread in the clean room.

For this reason, conventionally, when yellow phosphorus ignites, the ignited portion is covered with a metal foil, a fireproof mat or the like, and the work is performed again after the concentration of toxic substances in the room is reduced by ventilation. However, with this method, the work had to be interrupted many times, and the work time was extremely long.

To ignite yellow phosphorus, it is effective to apply water to the ignition part, but when water is applied to carbon parts such as the susceptor, the carbon is porous.
Not only does it take an extremely long time to dry it, but if a small amount of water remains in the susceptor, the water content in the susceptor will be evaporated and taken into the film during the next thin film formation, and the film quality will deteriorate. It is not preferable to use water, because it may cause water vaporization.

Particularly, in order to homogenize the film quality when forming a thin film, a vapor phase growth apparatus in which a susceptor for mounting a substrate is rotated (see Japanese Utility Model Laid-Open No. 3-106358).
In the case of (2), since many components such as the susceptor and a member that rotatably supports the susceptor are fixed in the reaction tube, it was necessary to avoid using water as much as possible.

Therefore, according to the present invention, it is possible to easily clean the inside of the reaction tube after the thin film is formed by using the raw material containing the phosphorus compound, and prevent the ignition of yellow phosphorus and the release of poisonous gas due to the yellow phosphorus. It is an object of the present invention to provide a cleaning device for a vapor phase growth apparatus that can safely clean a reaction tube and the like.

[0012]

In order to achieve the above object, a cleaning apparatus for a vapor phase growth apparatus of the present invention comprises a suction nozzle and an inert gas supply means for supplying an inert gas around the suction nozzle. Further, it is characterized in that the supply amount of the inert gas can be adjusted and the temperature of the inert gas is room temperature or lower.

[0013]

[Operation] According to the above configuration, an appropriate amount of the inert gas supplied from the inert gas supply means allows not only the vicinity of the suction nozzle but also the inside of the reaction tube to be in an inert gas atmosphere or have a low oxygen partial pressure. As a result, yellow phosphorus can be prevented from contacting oxygen and igniting, and the inside of the reaction tube can be cleaned safely and quickly. Further, by lowering the temperature of the inert gas, the activity of yellow phosphorus can be lowered, and yellow phosphorus can be made more difficult to ignite.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the embodiments shown in the drawings. FIG. 1 is a front view showing a first embodiment of a suction nozzle in a cleaning apparatus for a vapor phase growth apparatus according to the present invention, and the suction nozzle 1 is connected to a suction apparatus via a harm removing device (not shown). The suction pipe 2 and the inert gas jetting part 3 formed in a double pipe structure on the outer circumference of the tip end portion of the suction pipe 2. Inert gas spouting part 3
Is connected to an inert gas supply source (not shown) via a pipe 5 provided with a flow rate adjusting means such as a needle valve 4,
It is formed so as to eject an inert gas around the suction nozzle 1 from the ejection holes 6 formed on the peripheral surface.

The vapor phase growth apparatus shown in FIGS. 2 and 3 is a so-called horizontal type vapor phase growth apparatus in which the source gas is brought into contact with the substrate in parallel, and the source gas introduction tube 12 is provided at one end of the reaction tube 11.
With the gas exhaust pipe 13 at the other end,
In the reaction tube 11, a horizontal rotary holder 15 for holding the substrate 14 rotatably in the horizontal direction is installed. This vapor phase growth apparatus heats the substrate 14 to a predetermined temperature, introduces a predetermined source gas from the source gas introduction pipe 12 while rotating the horizontal rotary holding table 15, and heats the source gas at the substrate 14 portion. It is decomposed to form a predetermined thin film on the surface of the substrate 14, and at this time, a part of the thermal decomposition product adheres to the inner surface of the reaction tube 11 or the like. In the case of the vapor phase growth apparatus equipped with such a horizontal rotary holding table 15, it is not preferable to use water during cleaning as described above.

When the cleaning apparatus for vapor phase growth apparatus equipped with the suction nozzle 1 is used to remove and clean the deposits A and the like in the reaction tube 11, first, the flange 16 is disassembled to react. After removing the tube 11 from the vapor phase growth apparatus, as shown in FIG. 2, the suction nozzle 1 is inserted into the reaction tube 11, and the base of the suction tube 2 or an operation rod or the like provided separately is operated by hand. It can be done by doing so. It should be noted that the drive shaft 15 a for rotating the horizontal rotary holding table 15 has the connecting portion 15 a.
It is formed so as to be separable at b, and is separated at the same time when the reaction tube 11 is detached.

The vapor phase growth apparatus shown in FIG. 4 is a so-called vertical type vapor phase growth apparatus in which a source gas is brought into vertical contact with a substrate, and a source gas introduction pipe 22 is provided at the upper end and a gas exhaust is provided at the lower end. A substrate exchange chamber 24 is connected to a lower portion of a glass reaction tube 21 having a tube 23, and a susceptor 26 for mounting a substrate 25 is provided so as to be movable up and down. The partition plate 27 that separates the substrate exchanging chamber 24 descends, and the susceptor 26 also descends into the substrate exchanging chamber 24.

In this vapor phase growth apparatus, a part of the thermal decomposition product not deposited on the surface of the substrate 25 adheres to the inner surface of the reaction tube 21 and also drops on the upper surface of the partition plate 27. In such a vertical vapor phase growth apparatus, the cleaning is performed with the partition plate 27 itself attached, unless the cleaning is performed by overhauling the entire surface. However, when water is used, the susceptor 26 gets wet with water. Although this can be avoided, it is not preferable to use water at the time of cleaning in the same manner as described above, because water will flow to the drive mechanism and the like continuously provided at the lower portion of the partition plate 27.

As described above, when cleaning the vapor phase growth apparatus in which water cannot be used as a measure against the ignition of yellow phosphorus, the suction nozzle 1 formed as described above is used, and the suction nozzle 1 formed around By sucking the deposit A while supplying an active gas, generally nitrogen gas, the deposit in the reaction tube 11 is blocked while the contact between the yellow phosphorus and oxygen is blocked by the inert gas to prevent the ignition of the yellow phosphorus. It is possible to suck and remove A and the falling object A on the partition plate 27.

The supply amount of the inert gas at this time is preferably as large as possible for the purpose of shutting off the atmosphere, but is preferably as small as possible for suppressing the rise of the deposits due to the gas flow. 5 is provided with a flow rate adjusting means such as a needle valve 4 so that the supply amount of the inert gas can be adjusted,
It is desirable to adjust it appropriately depending on the place to be cleaned.
Further, even with the same amount of gas, the gas temperature is lowered by direct supply from the liquefied gas reservoir, etc., and the temperature of the deposit A containing yellow phosphorus is lowered to lower the activity of yellow phosphorus and prevent ignition. The effect can be further improved.

FIG. 5 is a cross-sectional view showing a second embodiment of the suction nozzle in the cleaning apparatus for a vapor phase growth apparatus of the present invention. The suction nozzle 31 has a flexible outer peripheral end of the suction tube 32. The skirt 33 is covered with a bellows-like skirt 33, and a pipe 34 for supplying an inert gas is provided in the skirt 33. Even when the suction nozzle 31 shown in this embodiment sucks and cleans the adhering matter A in the reaction tube 11 or the like, the pipe 3
The flow rate control valve 35 provided at 4 may be used while appropriately controlling the amount of the inert gas supplied into the skirt 33.

By cleaning as described above,
When cleaning the reaction tube and the like, the yellow phosphorus contained in the deposit A does not burn, and the work can be carried out safely and promptly, and the clean air in the clean room is not contaminated.

As the suction device and the abatement device connected to the suction nozzle, the conventional devices can be used as they are, and the description thereof will be omitted. In addition, before disassembling the vapor phase growth apparatus and removing the reaction tube, the above-mentioned JP-A-6-
By performing the method described in Japanese Patent No. 283429 or Japanese Utility Model Laid-Open No. 4-127642, the surface of yellow phosphorus is changed to a stable substance, so that the ignition of yellow phosphorus when the reaction tube is removed can be prevented. Then, the cleaning device of the present invention is used to remove the deposits, so that the cleaning operation can be performed more safely.

[0024]

As described above, since the cleaning apparatus for a vapor phase growth apparatus of the present invention sucks and removes the deposit while supplying the inert gas around the suction nozzle, the yellow phosphorus is ignited. The cleaning work can be performed while preventing the above, and the cleaning work can be performed safely and quickly. Further, since it is not necessary to use water, the adverse effect of water does not occur.

Further, by making it possible to adjust the supply amount of the inert gas, the supply amount of the inert gas can be adjusted to an optimum amount according to the cleaning place, and the ignition of yellow phosphorus and the rising of the deposits. Can be effectively prevented. In addition, by lowering the temperature of the inert gas, it is possible to lower the activity of yellow phosphorus and make it difficult to ignite.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of a suction nozzle in a cleaning apparatus for a vapor phase growth apparatus of the present invention.

FIG. 2 is a sectional front view showing an example of a horizontal vapor phase growth apparatus using the cleaning apparatus for a vapor phase growth apparatus of the present invention.

FIG. 3 is a sectional side view of the same.

FIG. 4 is a sectional front view showing an example of a vertical vapor phase growth apparatus using the cleaning apparatus for a vapor phase growth apparatus of the present invention.

FIG. 5 is a front view showing a second embodiment of the suction nozzle in the cleaning apparatus for vapor phase growth apparatus of the present invention.

[Explanation of symbols]

1 ... Suction nozzle, 2 ... Suction tube, 3 ... Inert gas ejection part,
4 ... Needle valve, 5 ... Piping, 6 ... Spout hole 11, 21, ...
Reaction tubes, 14, 25 ... Substrate, 15 ... Horizontal rotary holding stand,
16 ... Flange, 26 ... Susceptor, 27 ... Partition plate, A ...
Deposit

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-58-197725 (JP, A) JP-A-2-303023 (JP, A) JP-A-6-124891 (JP, A) JP-A-6- 283429 (JP, A) Actual flat 4-134838 (JP, U) Actual flat 4-127642 (JP, U) Actual flat 3-106358 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/205 C23C 16/44

Claims (3)

(57) [Claims] 1. A cleaning apparatus for a vapor phase growth apparatus, comprising: a suction nozzle; and an inert gas supply means for supplying an inert gas around the suction nozzle. 2. The cleaning apparatus for a vapor phase growth apparatus according to claim 1, wherein the supply amount of the inert gas is adjustable. 3. The cleaning apparatus for a vapor phase growth apparatus according to claim 1, wherein the temperature of the inert gas is room temperature or lower.