JP3047344B2 - Atmospheric pressure CVD 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 normal pressure CVD apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional atmospheric pressure CVD apparatus used in a manufacturing process of a semiconductor device includes a heater 1, a belt 2 for transporting a wafer 3, and an injector 4 for discharging a reactive gas. And an exhaust pipe 9 for exhausting the unreacted gas 10. The injector 4A includes an in-line type raw material gas line 5 for introducing a hydride gas such as silane, an oxygen line 7, a nitrogen line 6 for filling each gas line, and a cooling water line 8 for preventing heating of the injector 4A. These are fixed to an injector fixing portion 17 made of stainless steel or the like by bolts or the like. Then, the wafer 3 is placed on the heated belt 2 and the desired CVD film is formed by passing the wafer 3 immediately below the injector 4A, and the unreacted gas 10 not participating in the reaction on the wafer 3 is exhausted. It has a structure to be drawn to the pipe 9.

[0003] In the above-mentioned atmospheric pressure CVD apparatus, CVD is used.
When the film is formed, each unreacted gas blown from below the injector 4A comes into contact with the surface of the wafer 3 on the belt 2 and reacts.
Is discharged to The discharged unreacted gas 10 reacts with the outside air, and the reaction product 11 adheres to the inner wall. Therefore, the exhaust pipe 9 needs to be cleaned frequently. However, since the exhaust pipe 9 is fixed to the injector 4A, cleaning requires a long time since the injector 4A must be removed.

As a countermeasure, as shown in FIG. 5, a suction port for a duct 24 is provided between the bottom surface of a dispersion head (injector) 25 and a tray 22 on which a wafer 23 is placed, and the upper part of the suction port is dispersed. Japanese Patent Application Laid-Open No. 61-272377 discloses a structure in which the entirety of the reaction gas discharge port on the bottom surface of the John head 25 is connected so as to surround it.
No. 1993.

[0005]

However, in the atmospheric pressure CVD apparatus having the structure shown in FIG. 5, the reaction product 27 is placed on the side of the dispersion head (injector).
Does not adhere, but the amount adhered in the duct suction port does not change. Therefore, when cleaning the inside of the suction port, it is necessary to remove the injector, so that there is a problem that the replacement frequency (the number of times of cleaning) does not change much.

An object of the present invention is to solve the above-mentioned problems and to provide an atmospheric pressure CVD apparatus capable of greatly reducing the number of times of cleaning.

[0007]

An atmospheric pressure CVD apparatus according to the present invention is provided with a belt for carrying a semiconductor wafer thereon, an injector for blowing a reaction gas onto the wafer, and a side face of the injector. In an atmospheric pressure CVD apparatus having an exhaust pipe, means for cleaning the inside of the exhaust pipe at the same time as CVD film formation is provided , and a means for cleaning the inside of the exhaust pipe is provided .
The step comprises means for introducing an etching gas and etching.
Equipped with an etching gas flow control tube to control the gas flow direction
The tip of the above-mentioned etching gas flow control pipe is
It is characterized in that it is inserted into the suction port .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a first embodiment of the present invention.

Referring to FIG. 1, a normal pressure CVD apparatus includes a main belt 2 provided on a heater 1 for conveying a wafer 3, an injector 4 for blowing out a reaction gas, and an exhaust provided around the injector 4. Particularly, the injector 4 includes an in-line type raw material gas line 5 and an oxygen line 7 for introducing a hydride gas, a nitrogen line 6 for closing each gas line, and cooling for preventing heating of the injector 4. In addition to the water line 8, an etching gas introduction hole 12 and an etching gas flow control pipe 13 are provided between the tip of the introduction hole 12 and the suction port 9 </ b> A of the exhaust pipe 9.

According to the first embodiment thus constructed, the wafer 3 is placed on the belt heated by the heater 1, and when the reaction gas is discharged by the injector 4, the wafer 3 is placed immediately below the injector 4. 3, a film is formed on the wafer 3. The unreacted gas 10 that does not participate in the reaction on the wafer 3 is drawn to the exhaust pipe 9, and the reaction product 11 adheres to the inner wall of the exhaust pipe 9 with the passage of time, but the etching gas introduction hole 12 and the etching gas flow control pipe 13 By supplying the etching gas 15 such as HF vapor from the suction port 9A into the exhaust pipe 9 by the above, the reaction products 11 attached to the inner wall of the exhaust pipe 9 are removed. Therefore, the number of times of replacement and cleaning of the injector 4 fixed to the injector fixing portion 17 is drastically reduced. In other words, the conventional method requires cleaning once every 20 hours. However, in the present embodiment, the number of times of cleaning can be reduced to 1/5 or less since about 100 hours is sufficient.

When replacing the injector 4, a three-way valve 14 is provided so that the injector 4 can be purged with an inert gas 16.

The control pipe 13 for controlling the flow of the etching gas 15 has, for example, an etching gas inlet 18 and an etching gas outlet 19 as shown in FIG. 9 inlets 9
A is formed of ceramic or the like so as to lead to A. Therefore, the etching gas 15 can be supplied into the exhaust pipe 9 without affecting the CVD film formation.

FIG. 3 is a sectional view of a second embodiment of the present invention. The difference from the first embodiment shown in FIG.
A plurality of thin tubes 12A made of Teflon are used as a pipe for introducing an etching gas to be introduced into the inside, and a gas outlet 19A at an end thereof is inserted into a gas inlet 9A of an exhaust pipe 9, and other parts are provided. Is the same as in the first embodiment.

In the second embodiment constructed as described above, since the reaction products 11 in the exhaust pipe 9 are removed by the etching gas, the same effects as in the first embodiment can be obtained. The second embodiment has the advantage that the etching gas flow control pipe is not required unlike the first embodiment, and that the degree of freedom in designing the piping of the etching gas introduction thin tube 12A is increased.

[0015]

As described above, according to the present invention, by providing a means for introducing an etching gas into an exhaust pipe provided at the periphery of an injector for supplying a reaction gas, there is provided no influence on the CVD reaction. Since the reaction products attached to the inner wall of the exhaust pipe can be removed, the number of times of cleaning the injector can be significantly reduced.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of an example of an etching gas flow control tube used in the embodiment.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a conventional example.

FIG. 5 is a sectional view of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater 2 Main belt 3 Wafer 4 Injector 5 Raw material gas line 6 Nitrogen line 7 Oxygen line 8 Cooling water line 9 Exhaust pipe 9A Gas inlet 10 Unreacted gas 11 Reaction product 12 Etching gas introduction hole 13 Etching gas flow control pipe 14 Three-way valve 15 Etching gas 16 Inert gas for purging 17 Injector fixing part 18 Etching gas inlet 19 Etching gas outlet

Claims (3)

(57) [Claims] An atmospheric pressure CVD apparatus having a belt for carrying a semiconductor wafer thereon, an injector for blowing a reaction gas onto the wafer, and an exhaust pipe provided on a side surface of the injector. A means for cleaning the inside of the exhaust pipe at the same time as the film is provided ,
Means for introducing an etching gas and means for cleaning
Gas that controls the flow direction of the etching gas
A flow control pipe, a tip of said etching gas flow control pipe
Is a normal pressure CVD apparatus inserted into a gas inlet of an exhaust pipe . 2. A means for cleaning the exhaust pipe, the atmospheric pressure CVD apparatus according to claim 1, further comprising a plurality of etching gas inlet capillary. Wherein the etching gas introducing hole for introducing an etching gas, an atmospheric pressure CVD apparatus according to claim 1, characterized in that provided parallel to the injector and the exhaust pipe.