JPH06349760A - Fluid stable supply apparatus - Google Patents

Abstract

PURPOSE:To prevent the air from penetrating into a sample treating chamber through a gas exhaust tube which is the gas exhaust path of the sample treating chamber. CONSTITUTION:A gas exhaust tube 23 which is the gas exhaust path of a sample treating chamber 18 is composed of a first exhaust tube 23 through which drain fluid discharged from the sample treating chamber 18 flows and a second exhaust tube 24 through which fluid specially supplied from a fluid supply source flows and, further, the first exhaust tube 23 is so connected to the second exhaust tube 24 as to cross the second exhaust tube 24. With this constitution, when the fluid flows through the second exhaust tube 24, a negative pressure is created in the first exhaust tube 23 near the connection part of the first exhaust tube 23 and the second exhaust tube 24, so that it can be avoided that the drain fluid discharged from the sample treating chamber 18 through the first exhaust tube 23 is sucked into the second exhaust tube 24 and the air penetrates into the sample treating chamber 18 through the first exhaust tube 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, an oxidation device which is one manufacturing device of a semiconductor pressure sensor, a device for diffusing dopants such as boron and phosphorus into silicon, and forming an oxide film on the surface of a silicon wafer. Or a stable gas supply device capable of stably supplying a processing gas for controlling the diffusion rate of a dopant at a constant flow rate.

[0002]

2. Description of the Related Art For example, in the process of manufacturing a semiconductor pressure sensor, when oxidizing a silicon wafer, hydrogen gas, oxygen gas, nitrogen gas, etc. are sequentially placed in a quartz tube which is a closed space in which the silicon wafer is placed. It is necessary to supply the gas, and the supply amounts of these gases are controlled by a mass flow controller provided in the middle of the gas supply pipe. The gas supplied into the quartz tube is exhausted to the outside through the gas exhaust tube.

[0003]

By the way, in the above-mentioned oxidizing apparatus, when supplying gases such as hydrogen gas, oxygen gas and nitrogen gas to the quartz tube, the supply amount of these gases is very small. , The outside air may enter the reaction chamber, which is a quartz tube, through the gas exhaust tube, which causes the oxide film formed on the silicon wafer to have a non-uniform film thickness, or the dopant diffusion rate to not be constant. However, there is a problem that a good sensor cannot be obtained.

The present invention has been made in view of the above circumstances, and can prevent outside air from entering the reaction chamber through the gas discharge pipe and prevent the composition of the reaction gas from changing with time. This makes it possible to provide a stable gas supply device capable of manufacturing a high-quality sensor, for example, by making the film thickness of an oxide film formed on a silicon wafer uniform or by maintaining a constant diffusion rate of a dopant. To aim.

[0005]

In order to achieve the above object, the present invention provides a fluid supply pipe for supplying a fluid such as oxygen or nitrogen to a sample processing container in which a sample such as a silicon wafer is placed, A fluid discharge pipe for discharging the fluid in the sample processing container as a drain fluid; a first discharge pipe through which the drain fluid discharged from the sample processing container flows; and a fluid supply source And a second discharge pipe through which a fluid separately supplied from is circulated. Further, the first discharge pipe is connected to intersect with the second discharge pipe.

[0006]

According to the present invention, a fluid discharge pipe for discharging the fluid in the sample processing container as a drain fluid is provided, and this fluid discharge pipe serves as a first discharge pipe through which the drain fluid discharged from the sample processing container flows. , A second discharge pipe through which a fluid separately supplied from a fluid supply source flows, and the first discharge pipe is connected to intersect with the second discharge pipe. When the fluid flows along the discharge pipe, a negative pressure is generated in the vicinity of the connecting portion of the first discharge pipe connected to the second discharge pipe, whereby the sample is discharged from the sample processing container through the first discharge pipe. The drained fluid is drawn into the second discharge pipe. That is, according to the present invention, outside air is prevented from entering the sample processing container through the first discharge pipe of the fluid discharge pipe.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In this figure, reference numeral 1 indicates a hydrogen gas cylinder which is a supply source of hydrogen gas, reference numeral 2 indicates an oxygen gas cylinder which is a supply source of oxygen gas, and reference numeral 3 indicates nitrogen which is a supply source of nitrogen gas. A gas cylinder,
The gas stored in each of the cylinders 1 to 3 is transported through the pipes 4 to 6. Further, in the middle of each of the pipes 4 to 6, an on-off valve 7 to 12 for opening and closing the flow path, and a mass flow controller 13 to adjust the gas supply amount.
15 are provided respectively, and further, these pipes 4 to 6 are merged at the merge portion and then become one pipe 16.

Further, the pipe 16 is branched into two parts at a branch part 16A, one of the branched pipes 17 is connected to one end of a reaction chamber 18, and the other pipe 19 is connected to a T-shaped pipe 20. Has been done. The reaction chamber 18 is composed of, for example, a quartz tube having an inner diameter of 100 to 200 mm, and the reaction chamber 18 has a pipe 1
Gases such as hydrogen, oxygen, and nitrogen are supplied through 7, and the gas supplied into the reaction chamber 18 is connected to the other end of the reaction chamber 18 through a T-shaped tube 20. It is designed to be discharged as drain gas through. In addition, the reaction chamber 1
For example, a silicon wafer, which is the base of the semiconductor pressure sensor, is placed as a sample A on the base 21 in the sample 8, and is subjected to a treatment such as oxidation by a gas such as oxygen supplied through the pipe 17. It has become so. Also,
Around the reaction chamber 18, an electric furnace 22 for setting the reaction temperature in the reaction chamber 18 to an optimum value.
Is provided.

Next, the T-shaped pipe 20 arranged between the reaction chamber 18 and the pipe 19 will be described. The T-shaped pipe 20 includes a first discharge pipe 23 through which the drain gas discharged from the reaction chamber 18 flows, and a second discharge pipe 23 through which gas separately supplied from the gas cylinders 1 to 3 through the pipe 19 flows. A discharge pipe 24, and a first discharge pipe 23
Is connected so as to be orthogonal to the second discharge pipe 24,
And, these first discharge pipe 23 and second discharge pipe 24,
They are arranged in a T shape as a whole. In the T-shaped pipe 20 having the above-described configuration, when the gas goes straight through the second exhaust pipe 24, the vicinity of the connection portion of the first exhaust pipe 23 connected to the second exhaust pipe 24 is negative. As a result, the drain gas discharged from the reaction chamber 18 is drawn into the second discharge pipe 24 through the first discharge pipe 23, and as a result, outside air is discharged through the first discharge pipe 23 into the reaction chamber 18. Is prevented from getting inside. The inner diameter of the T-shaped tube 20 is 5 so that the T-shaped tube 20 does not come off from the reaction chamber 18 when gas is supplied and pressurized in the reaction chamber 18.
It is set to about 10 mm.

A mass flow controller 25 for adjusting the flow rate of gas is provided in the middle of the pipe 17 leading to the reaction chamber 18, and the T-shaped pipe 2 is provided.
An on-off valve 26 is provided in the middle of the pipe 19 leading to 0.

Next, the usage of the fluid stable supply device constructed as described above will be explained. The following (1)
In (2), cylinders 1 to 3 are attached to the reaction chamber 18.
An example of the case where the gas inside is supplied at a minute flow rate will be described. (1) One of the gas cylinders 1 to 3, for example, when oxygen gas is to be supplied from the oxygen gas cylinder 2 to the reaction chamber 18, with the open / close valves 8 and 11 open,
The mass flow controllers 14 and 25 are adjusted so that 5 to 10 liters /
Supply a large amount of oxygen gas at the rate of minutes. As a result, the gas existing in the reaction chamber 18 is removed from the T-shaped tube 20.
Is expelled through the first exhaust pipe 23 and the second exhaust pipe 24, and the inside of the reaction chamber 18 is replaced with oxygen gas. In this state, the on-off valve 26 is closed as well as the on-off valves 7, 9, 10, 12 to which the gas of other systems is supplied.

(2) Next, the on-off valve 2 in the middle of the pipe 19
6 is opened, oxygen gas is supplied to the second exhaust pipe 24 of the T-shaped pipe 20, and then the mass flow controller 25 on the side of the pipe 17 that supplies oxygen gas to the reaction chamber 18.
Is adjusted to set the flow rate of the oxygen gas supplied to the reaction chamber 18 to a minute amount. At this time, the flow rate (v1) of oxygen gas in the pipe 17 is set to be smaller than the flow rate of oxygen gas in the pipe 19 (v2). That is, the second of the T-tube 20
When the flow rate of the pipe 19 leading to the discharge pipe 24 of V.sub.2 is v2 and the flow rate of the pipe 17 leading to the first discharge pipe 23 of the T-shaped pipe 20 is v1, these flow rates v1 and v2 are as follows. Set. v1 <v2 Then, due to such a relationship, the pressure p1 in the first exhaust pipe 23 and the pressure p2 in the second exhaust pipe 24 are as follows. p1 <p2

By setting the mass flow controller 25 and the on-off valve 26, the oxygen gas supplied to the T-shaped pipe 20 through the pipe 19 flows through the second discharge pipe 24 of the T-shaped pipe 20 at a high flow rate. The first exhaust pipe 23, which goes straight and is connected to the second exhaust pipe 24 at that time
A negative pressure is generated in the vicinity of the connection part of the above, whereby the drain gas discharged from the reaction chamber 18 is drawn toward the second discharge pipe 24 through the first discharge pipe 23. As a result, outside air is prevented from entering the reaction chamber 18 through the first exhaust pipe 23, and the gas concentration in the reaction chamber 18 is kept constant without being affected by the external environment. That is, in the fluid stable supply device, outside air is prevented from entering the reaction chamber 18 through the first discharge pipe 23 of the T-shaped tube 20 connected to the reaction chamber 18, and the inside of the reaction chamber 18 is prevented. The gas concentration is kept constant so that the film thickness of the oxide film formed can be made uniform, or the diffusion rate of the dopant can be increased, for example, when performing an oxidation process for forming an oxide film on the silicon wafer in the reaction chamber 18. Can be maintained constant, and a good sensor can be manufactured.

In the above embodiment, the reaction chamber 1
An example of supplying nitrogen gas, hydrogen gas, or oxygen gas to the inside of the chamber 8 has been described, but the gas is not particularly limited, and the process performed in the reaction chamber 18 is not limited to the silicon wafer. However, the oxidation treatment is not limited to the above. Further, in the above embodiment, a gas such as oxygen or nitrogen was used as the fluid, but the fluid is not limited to this and may be a liquid.

Further, in the above embodiment, the first discharge pipe 23
Used the T-shaped pipe 20 connected so as to be orthogonal to the second discharge pipe 24, but the present invention is not limited to this, and as shown in FIG. 2, the first discharge pipe 23a is the second discharge pipe. The pipe 24a is obliquely connected to the first discharge pipe 23a and the second pipe.
Fluid discharge pipe 30 connected so as to be line-symmetric with the discharge pipe 24 of the first discharge pipe 24, or the first discharge pipe 2 as shown in FIG.
It is also possible to use the fluid discharge pipe 30 in which 3b is obliquely connected to the second discharge pipe 24b. Further, the present invention is not limited to this, and the tip portion of the second discharge pipe 24c may be connected to the first discharge pipe 2
Fluid discharge pipe 50 having a double pipe structure with 3c disposed inside
May be used.

[0016]

As is apparent from the above description, in the present invention, a fluid discharge pipe for discharging the fluid in the sample processing container as a drain fluid is provided, and the fluid discharge pipe is used for the drain discharged from the sample processing container. A first discharge pipe through which the fluid flows,
A second discharge pipe through which a fluid separately supplied from a fluid supply source flows, and the first discharge pipe is connected so as to intersect the second discharge pipe. When the fluid flows through the discharge pipe, a negative pressure is generated in the vicinity of the connection portion of the first discharge pipe connected to the second discharge pipe, whereby the sample is discharged from the sample processing container through the first discharge pipe. Drain fluid is drawn into the second drain. That is, according to the present invention, it is possible to prevent outside air from entering the sample processing container through the fluid discharge pipe and prevent the composition of the reaction gas from changing with time, and thus, for example, a film of an oxide film formed on a silicon wafer. The thickness can be made uniform, or the diffusion rate of the dopant can be maintained constant, and an effect that a good sensor can be manufactured can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing another example of the embodiment of the present invention.

FIG. 3 is a diagram showing another example of the embodiment of the present invention.

FIG. 4 is a diagram showing another example of the embodiment of the present invention.

[Explanation of symbols]

 1 Hydrogen Gas Cylinder (Fluid Supply Source) 2 Oxygen Gas Cylinder (Fluid Supply Source) 3 Nitrogen Gas Cylinder (Fluid Supply Source) 17 Piping (Fluid Supply Pipe) 18 Reaction Chamber (Sample Processing Container) 20 T-Shaped Tube (Fluid Discharge Pipe) 23 1 discharge pipe 24 2nd discharge pipe 30 fluid discharge pipe 40 fluid discharge pipe 50 fluid discharge pipe

Claims (1)

[Claims] 1. A fluid supply pipe for supplying a fluid such as oxygen gas or nitrogen gas to a sample processing container in which a sample such as a silicon wafer is placed, and a fluid in the sample processing container is discharged as a drain fluid. A fluid discharge pipe, wherein the fluid discharge pipe has a first discharge pipe through which the drain fluid discharged from the sample processing container flows, and a second discharge pipe through which a fluid separately supplied from a fluid supply source flows. And a pipe, and the first discharge pipe is connected to the second discharge pipe so as to cross the stable fluid supply device.