JP2576602B2 - Reaction tube cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] When depositing a polycrystalline silicon film, a silicon oxide film, a silicon nitride film, etc. on a semiconductor wafer surface, cleaning deposits such as polycrystalline silicon adhered to an inner wall of a reaction tube. When forming a polycrystalline silicon film on the surface of a semiconductor wafer, the semiconductor wafer is set vertically and placed inside the reaction tube, and the polycrystalline silicon film, silicon oxide film, etc. A rotating tube that rotates the reaction tube while holding the reaction tube vertically, with the object of supplying a reaction tube cleaning device that also enables the cleaning of attached objects to be cleaned, for example, heat treatment jigs; And move up and down inside the reaction tube through
In a reaction tube cleaning apparatus having an injection nozzle for injecting a liquid and a gas in a lateral direction, a support rod capable of suspending an object to be washed is planted on an inner wall of a rotary cylinder, and the object is injected from the injection nozzle to the object to be washed. A funnel-shaped liquid receiver for receiving the liquid falling from the object to be washed and dropping the liquid through the inside of the reaction tube is provided around.

[Industrial applications]

The present invention relates to a reaction tube cleaning apparatus for cleaning a deposit such as polycrystalline silicon adhered to an inner wall of a reaction tube when a polycrystalline silicon film or the like is formed on a semiconductor wafer surface.

The semiconductor element manufacturing process includes a film forming process for forming a polycrystalline silicon film or the like on the surface of a semiconductor wafer.

The polycrystalline silicon film and the like are simultaneously attached to the inner wall of the reaction tube and the surface of the heat treatment jig used for the film forming operation of the polycrystalline silicon film and the like.

A thick polycrystalline silicon film or the like is deposited on the inner wall of the reaction tube or the surface of the heat treatment jig repeatedly used in this film forming operation.

Therefore, outgassing from the polycrystalline silicon film or the like deposited on the surface during the film forming operation increases.

As a result, the physical properties of the polycrystalline silicon film formed on the surface of the semiconductor wafer are adversely affected.

Therefore, it is necessary to wash the reaction tube and the heat treatment jig used in the film forming operation repeatedly about 5 to 15 times to remove deposits such as a polycrystalline silicon film adhered to the inner wall and the surface.

[Conventional technology]

Conventionally, a widely used method of cleaning a reaction tube is to vertically rotate the reaction tube and rotate it in the circumferential direction of the reaction tube. A solution such as hydrofluoric acid or hydrofluoric acid is sprayed from the nozzle onto the inner wall of the reaction tube to chemically dissolve the deposits such as the polycrystalline silicon film, and then a cleaning liquid, for example, pure water is sprayed onto the inner wall of the reaction tube. After washing away the adhering solution of hydrofluoric acid, hydrofluoric acid or the like, finally, a gas, for example, nitrogen gas is injected to dry the pure water adhering to the inner wall of the reaction tube.

The above-mentioned conventional method for cleaning a reaction tube will be described with reference to a partial side sectional view of a cleaning apparatus used for cleaning the inner wall of the conventional reaction tube shown in FIG.

1 is a reaction tube, 2 is a rotation tube, 4 is a fixed band, 4a is a support rod, 5 is an injection nozzle, 6 is a supply tube, A is a rotation direction of the reaction tube 1 and the rotation tube 2, and the reaction tube 1 is shown in the figure. The drive unit (not shown) is fixed to substantially the center of the rotary cylinder 2 by a fixed band 4 at the tip of a support rod 4a implanted inside the rotary cylinder 3 that rotates in the direction A, and is rotated by the rotation of the rotary cylinder 2 to rotate. It is washed by the washing method described above.

On the other hand, FIG. 3 is a sectional view in the order of steps showing a conventional cleaning method for cleaning the heat treatment jig 2.

(1) is a state in which the heat treatment jig 2 is immersed in an immersion tank 7 containing a solution of hydrofluoric nitric acid, hydrofluoric acid, or the like that chemically dissolves deposits on the surface of the heat treatment jig 2; The state where the heat treatment jig 2 is immersed in the immersion tank 7 containing pure water for cleaning the solution adhering to the surface of the heat treatment jig 2 after the processing of 1) is completed. After the treatment of (2) is completed, the pure water adhering to the surface of the heat treatment jig 2 is dried by injecting nitrogen gas into the heat treatment jig 2 by the air gun 8 as shown in FIG. The cleaning of the heat treatment jig 2 was performed according to the operation sequence.

[Problems to be solved by the invention]

As described above, since the cleaning devices for the reaction tube 1 and the heat treatment jig 2 are completely different, investment in the cleaning device is duplicated, the space required for a clean room with high equipment costs is increased, and the heat treatment jig is increased. Since the cleaning of No. 2 is performed by a manual operation, the number of cleaning steps is increased, and this is also a factor that increases the manufacturing cost of the semiconductor element.

An object of the present invention is to improve a reaction tube cleaning apparatus capable of cleaning the heat treatment jig 2 by a cleaning apparatus used for the reaction tube 1 in order to solve the above problems.

[Means for solving the problem]

The structure of the present invention for achieving the above object will be described with reference to FIG. 1 showing a partial cross section of an embodiment of the present invention and FIG. 2 showing a partial cross section of a conventional cleaning apparatus.

According to the present invention, a supporting rod 12 capable of suspending an object to be cleaned 2 is implanted on the inner wall of a rotary cylinder 3 as shown in FIG. A funnel-shaped liquid receiver 11 that receives the liquid that is ejected from the nozzle 5 onto the object 2 and falls from the object 2 and drops the liquid through the inside of the reaction tube 1 is provided.

(Operation)

Next, the operation will be described with reference to the partial side sectional view of one embodiment of the present invention shown in FIG.

The reaction tube 1 is held substantially at the center of the rotary cylinder 13 via the fixed band 4 and the support rod 4a, and the support rod 12 implanted on the inner wall of the rotary cylinder 13 suspends the heat treatment jig 2. It is.

In this state, when the rotary cylinder 13 rotates in the B direction by a driving device (not shown), the reaction tube 1 and the heat treatment jig 2 also rotate in the B direction.

Next, the injection nozzle 5 is controlled by a control device (not shown).
Heat treatment in which a solution of hydrofluoric nitric acid, hydrofluoric acid, etc., pure water and nitrogen gas are sequentially suspended from the support rod 12 while vertically moving through the opening of the rotary cylinder 2 and substantially at the center of the rotary cylinder 2. The heat treatment jig 2 can be cleaned by the reaction tube cleaning device by spraying the liquid onto the surface of the tool 2 and the inner wall of the reaction tube 1.

〔Example〕

 Next, an embodiment of the present invention shown in FIG. 1 will be described.

FIG. 1 is a partial side sectional view of a semiconductor jig cleaning apparatus according to the present invention. In the conventional reaction tube cleaning apparatus shown in FIG. 2, a rotating cylinder 13 is provided on the upper inner wall of a rotating cylinder 3 of the conventional reaction tube cleaning apparatus. A support rod 12 for suspending the heat treatment jig 2 is implanted, and a funnel-shaped liquid receiver 11 for receiving the liquid jetted from the injection nozzle to the heat treatment jig 2 and dropping the liquid through the inside of the reaction tube 1. It has been set around.

[Effects of the Invention] As is apparent from the above description, the reaction tube cleaning apparatus according to the present invention can clean the heat treatment jig and simultaneously clean the reaction tube. It is possible to avoid investment, reduce the required space of a clean room with high equipment costs, and automate the cleaning of the heat treatment jig 2, thereby reducing the number of cleaning steps, thereby contributing to a reduction in the manufacturing cost of semiconductor devices. Become.

[Brief description of the drawings]

FIG. 1 is a partial side sectional view of one embodiment of the present invention, FIG. 2 is a partial side sectional view of a conventional reaction tube cleaning apparatus, and FIG. 3 is a process side sectional view showing a conventional heat treatment jig cleaning method. Is shown. In the figure, 1 is a reaction tube, 2 is a heat treatment jig, 3 and 13 are turntables, 4 is a fixed band, 4a is a support rod, 6 is a supply tube, 11 is a liquid receiver, 12 is a support rod, and A is a reaction tube and a heat treatment jig. B indicates the direction of rotation of the tool and the rotary cylinder, and B indicates the direction of movement of the nozzle.

Claims (1)

(57) [Claims] The present invention is characterized in that a cylindrical reaction tube made of a heat-resistant material used in a heat treatment process for a semiconductor wafer is vertically held, and a rotating tube for rotating the reaction tube and an opening of the reaction tube are inserted to vertically move the inside of the reaction tube. A reaction tube cleaning apparatus having an injection nozzle for injecting a liquid and a gas in a lateral direction by moving, wherein a support rod (12) capable of suspending an object to be cleaned (2) on an inner wall of the rotary cylinder (3). And spray nozzle (5)
A funnel-shaped liquid receiver (11) for receiving the liquid sprayed onto the object to be cleaned (2) and falling from the object to be cleaned (2) and dropping the liquid through the inside of the reaction tube (1) is provided. A reaction tube cleaning apparatus characterized in that the reaction tube (1) and the object to be cleaned (2) can be washed.