JPS60235794A - Gas introduction device for gaseous phase growth - Google Patents

Abstract

PURPOSE:A device capable of carrying out rapidly stopping and beginning of introduction of a reaction gas, wherein two gas feed pipes are joined, its outlet is made to face a reaction pipe for gaseous phase growth, and a carrier gas of one pipe is made to flow partially into a reaction gas introduction pipe of the other. CONSTITUTION:In doping the substrate 9 with an impurity, the three-way cock 13 is handled as shown in the figure 1. As the raw material gas (C) having a flow rate controlled by the flowmeter 10, the doping gas (a) having a flow rate controlled by the flowmeter 1 and the carrier gas (b) having a flow rate controlled by the flowmeter 2 are introduced from the gas inlet pipes 16 and 19. The doping gas a is mixed and diluted with the carrier gas (b) at the tip 16a of the inlet pipe 16, provided with a flow velocity and flows towards the outlet 19a. In stopping the doping, the three-way cock 13 is then handled as shown in the figure 2, the carrier gas (b) in the gas inlet pipe 19 is made to flow dividedly at the tip 16a of the gas inlet pipe 16, flows partially backward in the gas inlet pipe 16, and the remaining doping gas a is exhausted to the exhaust pipe 20. consequently, the doping gas a flowing into the reaction pipe 8 is only the doping gas (a) at the part of the outlet 19a.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention utilizes gas phase chemical reactions to form a kidney by vapor phase growth, which releases a substance by 1 nm. Regarding a gas introduction device.

(Prior art) Among this type of gas introduction apparatus, for example, a vapor phase growth)-ping apparatus has a configuration as shown in FIG. 10 or 11, and the flow rate is controlled by a flow meter 1. Doping gas (dopant) a for reaction or carrier gas b whose flow rate is controlled by flow meter 2 (does not contribute to reaction) is switched by four-way valve 3 and introduced via piping 4 and joint 5. It is supplied to the pipes. The four-way valve 3 exhausts the other of the doping gas a and the carrier gas b, which is connected to the pipe 4 side, from the exhaust pipe 7. The opening 6a of the gas introduction tube 6 is located upstream of the substrate 9 placed in a reaction tube 8 whose internal pressure is higher than atmospheric pressure, and the exhaust from the reaction tube 8 is on the right side (in the figure). (not shown). Raw material gas C for reaction is introduced into reaction tube 8 from piping 10 via joint 11 and gas introduction tube 12 .

By the way, when stopping the supply of doping gas a in this device, the four carburetes 3 are moved from FIG. 10 to FIG. 11.
Switching to the state shown in the figure, carrier gas b is introduced into the gas introduction pipe 6, and the inside of the pipe at the gas introduction pipe [; The doping gas (a) is carried by the doping gas (a) and diffused by the gas (l), or remains in the gas pool in the joint 5.

Due to the influence of the doping gas a, etc., the supply of the doping gas is not rapidly stopped, and therefore the amount of topping to the substrate 8 is gradually reduced.

Therefore, in this device, for example, Ga used in a high frequency band
As the epicaxial crotch grows extremely thin.

In some cases, the steepness of the toping group in the growth direction was inhibited, making it difficult to improve the properties.

(Objective of the Invention) The present invention has been made in view of the above points, and the first object is to rapidly stop or stop and start the introduction of gas that contributes to the reaction in the reaction tube. A. Provides a gas introduction device for vapor phase growth.

That's true.

(Structure of the Invention) For this purpose, in the present invention, two gas introduction tubes are connected, and the outlet thereof faces into a reaction tube for vapor phase growth. , the introduction of the reaction gas is stopped by introducing the reaction gas into the other gas introduction pipe and diverting the carrier gas to the other gas introduction pipe. Connect the tubes so that the output 1 faces into the reaction tube for vapor phase growth.A carrier gas is introduced into one of the two gas introduction tubes, and a reaction waste is introduced into the other, and the The reaction gas is introduced (♀stopped) by connecting a discharge pipe to the gas introduction pipe and branching the carrier gas to the discharge fI].
By ceasing the separation of the carrier gas described in (1) to the discharge pipe (1), the introduction of the reaction gas described in (7) is started.

(Actual hb example) Below, 1. Examples of the present invention will be described. FIG. 1 shows an embodiment of the present invention, which relates to a vapor phase growth doping apparatus. In this example, the flow rate of the doping gas d was 1.3.
5 and the gas introduction pipe 16 into the reaction tube 8 (1
2, and the carrier gas b has a flow rate ril 2
, so that it can be introduced into the reaction tube 8 via the pipe 17, the joint 18 and the gas introduction tube 19, and the tip 1 fi a of the former gas introduction tube 16 is connected to the side surface of the tip portion of the rear gas introduction tube 19 4i. and the output 1 of the gas inlet pipe 19 of the l&.
+19a is on the upstream side of the substrate 9.

20 is an exhaust pipe (exhaust pipe) connected to the 3rd grade 13.

(When doping the substrate 9 with impurities, first cut the three carburetes 13 into small pieces, and introduce the raw material gas C whose flow rate is controlled by a flow meter IO. Therefore, 1Th controlled by flow rate i'111
A doping gas a of ffl and a carrier gas b whose flow rate is controlled at a flow rate of 1it2 are each introduced from a gas introduction pipe 1619. At this time, the l-ping gas a is supplied to the gas introduction pipe 16.
It is mixed and diluted with the carrier scum b at the tip 1a of the carrier sludge, and the flow rate is increased and the carrier sludge is collected and directed to the exit LJ I 9a (
Figure 3(a)).

Next, in order to stop the supply of doping gas a to stop doping in this state, switch 3 to the open state as shown in FIG. b is the tip 15 of the gas introduction pipe 16
The remaining doping gas a inside the doping gas is discharged from the three-way valve 13 to the exhaust pipe 20.

Therefore, "(, the doping gas a entering the reaction tube 8 is Ill
LI I 9 Only the doping gas a that was in the a part is replaced, that is, the gas is replaced at the tip 16a of the gas introduction pipe 16.
It is only necessary to replace the gas between the and the outlet 1119a of the gas introduction pipe 19, and the doping gas supply can be stopped much more rapidly than in the past.

The gas flow shown in Figure 3 can be easily controlled by using an electrically controllable mass flow needle for the flowmeter and a solenoid valve for the 3-way valve, and program control is also possible. It is.

In addition, in order to improve the effect of the device of this example,
At the same time as reducing the doping gas a in the gas introduction tube 16, spacers 21 and 22 are placed before and after the joint of the tip 16a of the gas introduction tube 16 in the gas introduction tube 19, as shown in FIG. If placed, the flow velocity in this part can be increased, and it is possible to prevent backflow and speed up replacement.

Further, as shown in FIG. 5, the gas introduction pipes 16 and 19 are double-layered, with a gas introduction pipe 16' for introducing the doping gas a inside a waste introduction pipe 19' for introducing the carrier gas b. structure, and the outlet n19a of the gas introduction pipe 19'
' Hand 11: Arrange so that the outlet 162' of the gas inlet pipe 16' is located at J - (Both gas inlet pipes +6' and 19
′ can also be combined. In this case, the outlet 16a' widens its outer diameter to form a constriction within the gas introduction pipe 19'.

FIG. 6 shows a doping apparatus according to another embodiment. The same reference numerals are used for parts that perform the same functions as those in the above embodiment. In this embodiment, no valve is used, and in addition to the gas introduction pipe 16 for the doping gas a and the waste introduction pipe 19 for the carrier gas b, a discharge pipe 23 is also arranged in the reaction tube 8. Then, the tip 19 of the gas introduction pipe 19 is attached to the side surface in front of the outlet D 23a of the discharge pipe 23.
b is connected, and the tip 16b of the gas introduction pipe 6 is connected to the side surface of the connected portion. 24 is a joint, 2
5 is a pipe, and 26 is a flow needle.

In this embodiment, only by controlling the gas flow using a flowmeter, it is possible to not only stop the introduction of the doping gas a but also start the introduction very quickly.

Figure 7+81 shows the gas flow when the doping gas a is stopped (l) introduced into the reaction tube 8. In this case, for example, the discharge flow rate a126 is controlled to increase the discharge rate. Alternatively, the amount of carrier gas b is increased by controlling the flow rate ηI2, or the amount of doping gas a is decreased by controlling the flow rate IiL1. ! 91) and a part of it flows to the discharge pipe 23 side, so the doping gas a
also flows in that direction.

Therefore, the doping gas a is exhausted from the exhaust pipe 20 together with a portion of the carrier gas b.

- force, Figure 7 +81 is the doping gas a into the reaction tube 8
In this case, the flow rate ri is 11.2 or 2
Control 6. Thereby, the doping gas a introduced from the gas introduction pipe 16 is transferred to the tip 16 of the waste introduction pipe 16.
The -g(4) is diluted by the carrier gas b introduced from the gas introduction tube 19, is given an i* stream, and is introduced into the reaction tube 8 from the output (12; ua). Note that another part of the doping gas a separated at the tip 16a is passed from the gas introduction pipe 23 to the exhaust pipe 20 (1).

Therefore, in this embodiment, when starting or stopping the introduction of the doping gas a, it is sufficient to replace the gas in an extremely short period from the tip 16b indicated by G, 1, and F to the above-mentioned Ll 23a. There is no gas accumulation as seen in other systems, and switching is possible extremely quickly.

Therefore, it is possible to quickly start and stop the introduction of the doping gas a, and it is possible to achieve an extremely steep change in the impurity concentration in the vapor phase IQI (f4).

In Fig. 8, spacers 27 to 29 are arranged on the inner wall of the gas introduction pipe 19 at the tip 191), which reduces the flow velocity in that part and prevents backflow. , the replacement of dregs can be made faster. The spacers 27 to 29 also have the effect of increasing the pressure inside the pipe and facilitating control of the flow balance.

FIG. 9 shows a modification in which a gas introduction pipe 16'' and a gas introduction pipe 19'' are provided inside the gas introduction pipe 23' which functions as an exhaust pipe. 16b'' and +9b'' are the tips of the gas introduction pipes 16'' and 19'', respectively, and 233' is the outlet 1''. Gas inlet pipes 16" and 19" are combined, and their outlets come out! ', j 23 a', and the gas introduction pipe 16
" is the inlet side of the discharge pipe 23', and the discharge pipe 23'
is combined with

In the embodiment described in "-", an example was explained in which the doping gas a was introduced, but in the embodiment shown in FIG. It is also possible to introduce raw material gas (1) and form vapor phase growth (1-1) on l!N- using the raw material.

In addition, the inlet pipe 16, 19 and the discharge pipe 23 are set as one set,
A plurality of sets are provided in pairs (7) in one reaction tube 8, and each set receives 7J of different raw material gas.

If you try to start and stop people, you will be able to do it.
It can also be used to introduce raw material gas for OM-VPE (organic metal vapor phase epitaxy), which introduces materials in a gaseous state.

In this case, it is possible to rapidly start and stop the introduction of the summer wood gas, thereby making it possible to make a sharp change in the composition within the adult Gtl'A. Therefore, it becomes possible to grow a mixed crystal compound conductor having a Peter junction with an extremely steep change in composition, and it is also possible to realize a precise superlattice structure.

(Effects of the Invention) As explained below, according to the present invention, gas introduction can be stopped or stopped and started rapidly.
A) The concentration change of the vapor-phase IQ layer formed by the gas can be made steep.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a vapor phase formation 14 doping device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the same device in a state where the three-way valve gold is switched, Fig. 3 fa + (bl is the Or the second
An explanatory diagram of the gas flow in the figure, Fig. 4 is a diagram showing an improved example of the same device in which a spacer is provided inside the pipe, Fig. 5 is a diagram showing a modified example in which the pipe has a two-wheel structure, and Fig. 6 is a diagram showing the main part. Another fruit of invention, fi
T! Explanatory diagram of the vapor phase growth doping apparatus of example i, FIG. 7f
a+, (bl is an explanatory diagram of gas flow in the apparatus of FIG. 6,
Figure 8 shows an improved example of the same device in which a spacer is provided inside the tube, and Figure 9 shows a modified example of the same device in which a tapeworm is used as the tube.
, 10-1 and 11 are explanatory diagrams of conventional doping devices. 1.2...Flow rate n1.3...4-way valve, 4...
Piping, 5... Fitting, 6... Gas introduction pipe, 7... 1
]1 Trachea, 8...Reaction tube, 9...Substrate, IO...
Flowmeter, 11...Joint, 12...Gas introduction pipe, 13
... 3-way valve, 14... Piping, 15... Navy blue; 1
', 16...Gas introduction pipe, 17...Piping,! 8...
[Connection]-1" 9...Gas introduction pipe, 20...υ[Trachea,
21.22... Spacer, 23... Discharge pipe, 24
...Joint, 25...Distribution, 26...Flow rate if, 2
7-29...Spacer. Patent applicant New Japan Radio Co., Ltd. Agent Patent attorney Long JV Tomei Figure 7 Figure 8 Figure 9 Figure 10 Temple #1lTff”艮 IjI Month 1M

Claims (1)

[Claims] (11. Two gas introduction tubes are connected and the output I-1 is brought into the reaction tube for vapor phase growth. A gas phase characterized in that the introduction of the reaction gas is stopped by separately introducing the reaction gas and diverting the carrier gas to the other gas introduction pipe. Gas introduction device for growth. +21. Gas introduction device for vapor phase growth according to claim 1, characterized in that the reaction gas described in J1 is a doping gas. (: (), two gases Connect the inlet tubes so that their output faces into the reaction tube for vapor phase growth, and introduce the carrier gas into one of the two gas inlet tubes and the reaction gas into the other. The introduction of the reaction gas is stopped by connecting a discharge pipe to the other gas introduction pipe and branching the carrier gas to the discharge pipe.
(4) Gas-phase acid 1:c river waste introduction device characterized in that the introduction of the reaction gas is started by stopping the IJ11 to the Degawa pipe. The gas introduction device for vapor phase growth according to claim 3, characterized in that the reaction gas is a topi gas, an oxidation gas, or a raw material gas. Discharge pipe I
The gas introduction device for vapor phase growth according to claim 3, wherein a plurality of sets are installed in the reaction tube.