JP2500421Y2 - Low pressure chemical vapor generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] In a semiconductor device manufacturing process, there is a process of forming various thin films of silicon polycrystal, silicon nitride, silicon oxide, etc. by a low pressure chemical vapor deposition apparatus.

The present invention relates to a low-pressure chemical vapor deposition apparatus for reducing the amount of a product other than the production membrane attached to the production membrane as foreign matter in the low-pressure chemical vapor deposition apparatus.

[Conventional technology]

FIG. 2 is a vertical sectional view showing the configuration of an example of a conventional device. In Fig. 2, 1 and 2 are internal and external quartz reaction tubes, 3 respectively.
Is a quartz boat inserted in the inner quartz reaction tube 1, and a large number of wafers 4 are mounted side by side. Quartz boat 3
Is installed on the cap 8, and a gas injection port 5 for injecting a reaction gas into the inner quartz reaction tube 1 is provided in the lower part. Reference numeral 9 is a heater for heating the internal boat 3 and the wafer 4 mounted thereon, 10 is an exhaust pipe provided below the inner and outer quartz reaction tubes 1 and 2, and 11 is inserted into the exhaust pipe 10. It is a pressure control valve.

In such a conventional apparatus, when a reaction gas is injected into the inner quartz reaction tube 1 through the gas injection port 5, the reaction gas flows along the inner surface of the inner quartz reaction tube 1, and the inside of the inner quartz reaction tube 1 is opened. Exhaust gas is exhausted by an exhaust device connected to the exhaust pipe 10 while passing through the outer quartz reaction tubes 1 and 2 and being controlled to a constant pressure by a pressure control valve 11 inserted in the exhaust pipe 10. In this state, the wafer 4 is heated to a predetermined temperature by the heater 9 and reacts with the reaction gas to form a formed film on the wafer 4.

[Problems to be solved by the device]

However, in the above-mentioned conventional example, the gas flows as shown by the arrow, and a gas retention region is formed in the upper inner portion of the outer quartz reaction tube 2. Since the amount of the product in this retention region is larger than that in the wafer region and the amount of the product attached to the inner upper part of the outer quartz reaction tube 2 is also large, the quartz boat 3 on which a large number of wafers 4 are mounted is set in the internal quartz. When it is inserted into the reaction tube 1, after the thin film formation on the wafer 4 is completed, when the reaction tubes 1 and 2 are evacuated to atmospheric pressure with an inert gas such as N ₂ or Ar,
There is a problem that the amount of the product attached to the upper inside of the outer quartz reaction tube 2 is peeled off and attached to the wafer 4 as a foreign matter, and the outer quartz reaction tube 2 needs to be frequently cleaned.

[Means for solving the problem]

In order to solve the above-mentioned problems, the device of the present invention has a double pipe 1, 2 structure as shown in the first illustration, and a boat 3 on which a large number of wafers 4 are mounted side by side is inserted into the inner reaction pipe 1. In the vertical low-pressure chemical vapor phase generator in which the reaction gas is injected from the lower gas injection port 5 and exhausted from between the inner reaction tube 1 and the outer reaction tube 2, an exhaust hole 7 is provided at the top of the inner reaction tube 1. The upper shape 1a of the inner reaction tube 1 is fitted to the upper curved shape 2a of the outer reaction tube 2, and the upper curved shape 1a of the inner reaction tube 1 is attached to the upper portion of the boat 3.
The gas flow smoother 6 adapted to the above is installed.

[Action]

A gas flow smoother 6 in which an upper shape 1a having an exhaust hole 7 at the top of the inner reaction tube 1 is fitted to the upper curved shape 2a of the outer reaction tube 2 and an upper curved shape 1a of the inner reaction tube 1 is fitted to the upper portion of the boat 3. By installing the reaction gas, the reaction gas smoothly flows between the upper curved portion of the inner reaction tube 1 and the upper curved portion of the gas flow smoother 6, passes through the exhaust hole 7 at the top of the inner reaction tube 1, and the inner and outer reaction tubes Since it will flow smoothly along the curved surfaces of 1 and 2, there will be no reaction gas retention area at the upper inside of the outer reaction tube 2, and the amount of reaction products deposited will be reduced and foreign substances will be peeled off during thin film formation. It is extremely rare that the wafer drops and adheres to the wafer 4.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view showing the configuration of an embodiment of the device of the present invention. Reference numerals 1 and 2 are internal and external quartz reaction tubes, and 3 is a quartz boat inserted in the internal quartz reaction tube 1, and a large number of them are provided. Wafers 4 are mounted side by side. The quartz boat 3 is installed on a cap 8, and a gas injection port 5 for injecting a reaction gas into the internal quartz reaction tube 1 is provided in the lower part. 9
Is a heater for heating the inner boat 3 and the wafer 4 placed on it, 10 is an exhaust pipe provided under the inner and outer quartz reaction tubes 1 and 2, and 11 is inserted into the exhaust pipe 10. It is a pressure control valve.

In this embodiment, in the low pressure chemical vapor phase generator having such a structure, the upper shape 1a having the exhaust hole 7 at the top of the inner quartz reaction tube 1 is matched with the upper curved shape 2a of the outer quartz reaction tube 2, and the quartz boat 3 is used. A quartz gas flow smoother 6 matching the upper curved shape 1a of the inner quartz reaction tube 1 is installed on the upper part of the.

When the reaction gas is injected into the internal quartz reaction tube 1 through the gas injection port 5 in this embodiment having such a configuration, the reaction gas flows along the inner surface of the internal quartz reaction tube 1 and the internal quartz reaction tube 1 and the gas flow. The curved shape 1 between the smoothers 6
Curved shapes 1 of the inner and outer quartz reaction tubes 1 and 2 flow along the a and 6a planes and through an exhaust hole 7 provided at the top of the inner quartz reaction tube 1.
Flowed along the surfaces a, 2a, passed between the inner and outer quartz reaction tubes 1 and 2, and was connected to the exhaust pipe 10 while being controlled to a constant pressure by a pressure control valve 11 inserted in the exhaust pipe 10. Exhausted by the exhaust device. In this state, the wafer 4 is heated to a predetermined temperature by the heater 9 and reacts with the reaction gas to form a formed film on the wafer 4.

In this embodiment, the upper shape 1a having the exhaust hole 7 at the top of the inner quartz reaction tube 1 is matched with the upper curved shape 2a of the outer quartz reaction tube 2, and the upper curved shape of the inner reaction tube 1 is placed on the upper portion of the boat 3.
Since the gas flow smoother 6 adapted to 1a is installed, the reaction gas smoothly flows between the upper curved portion of the internal quartz reaction tube 1 and the upper curved portion of the gas flow smoother 6, and Through the exhaust hole 7, through the inner and outer quartz reaction tubes 1,
Because it will flow smoothly along the curved surface of 2,
There is no reaction gas retention area in the upper inside of the outer quartz reaction tube 2 and the amount of the reaction products attached is small, so that foreign matters are less likely to be peeled off and attached to the wafer 4 during thin film formation.

Conventionally, when a silicon oxide film is formed on the wafer 4 by using SiH ₄ —N ₂ O as a reaction gas, the amount of adhered particles is 50
Although the reaction tubes 1 and 2 were cleaned every 30 batches to keep the number of wafers / wafer, in the case of this embodiment, 50 batches or more, 50 pieces /
It can be kept below the wafer, and it is not necessary to wash the reaction tubes 1 and 2 for a long period of time.

[Effect of device]

As described above, according to the present invention, the upper shape 1a having the exhaust hole 7 on the top of the inner reaction tube 1 is matched with the upper curved shape 2a of the outer reaction tube 2, and the upper part of the inner reaction tube 1 is attached to the upper part of the boat 3. Since the gas flow smoother 6 adapted to the curved shape 1a is installed, the reaction gas smoothly flows between the upper curved portion of the inner reaction tube 1 and the upper curved portion of the gas flow smoother 6, and Since it flows smoothly through the exhaust holes 7 and along the curved surfaces of the inner and outer reaction tubes 1 and 2, there is no retention area of the reaction gas in the inner upper part of the outer reaction tube 2.
It is extremely unlikely that foreign matter will be peeled off and adhered to the wafer 4 during the thin film formation due to the small amount of the reaction products attached, and it is necessary to clean the inner and outer reaction tubes 1 and 2 for a long period of time. There is no effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing the construction of an embodiment of the device of the present invention,
FIG. 2 is a vertical sectional view showing the configuration of an example of a conventional device. 1 ... internal (quartz) reaction tube, 1a ... upper curved shape, 2 ...
… External (quartz) reaction tube, 2a …… Upper curved shape, 3 ……
(Quartz) boat, 4 ... Wafer, 5 ... Gas inlet,
6 ... (made of quartz) gas flow smoother, 6a ... upper curved shape, 7 ... exhaust hole.

Claims (1)

(57) [Scope of utility model registration request] 1. A boat (3) having a double tube (1, 2) structure and having a large number of wafers (4) mounted side by side is inserted into an internal reaction tube (1), and a gas injection section at the bottom is inserted. In a vertical low pressure chemical vapor phase generator in which a reaction gas is injected from an inlet (5) and exhausted from between an inner reaction tube (1) and an outer reaction tube (2),
The upper shape (1a) having the exhaust hole (7) on the top of the inner reaction tube (1) is matched with the upper curved shape (2a) of the outer reaction tube (2), and the inner reaction is performed on the upper part of the boat (3). Gas flow smoother (6) matching the upper curved shape (1a) of the pipe (1)
A low-pressure chemical vapor generator that is installed.