JPS60247933A - Semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To prevent the soft evaporation of a hydrogen flowing-in part consisting of quartz by a method wherein, in a device with which steam is obtained by burning hydrogen gas, a combustion chamber and a mixing chamber in which noninflammable gas is mixed in the steam generated in the combustion chamber are separately provided. CONSTITUTION:A combustion chamber 11, wherein hydrogen gas and oxygen gas are mixed and burned, is provided and at the same time, a mixing chamber 15 separated by an isolating plate 16 is provided. A hole 17 is formed on the isolating plate 16, and the steam generated in the combustion chamber 11 is introduced to the mixing chamber 15 through the intermediary of the hole 17. The diluting oxygen supplied from a flow-in hole 18 is mixed to the steam supplied from the hole 17 in the mixing chamber 15, and mixed substance is introduced into a processing tube 19. As the combustion chamber is provided separately from the mixing chamber as above-mentioned, a hydrogen flame 22 is maintained at a suitable temperature, thereby enabling to prevent the generation of soft evaporation of the quartz material constituting the nozzle part of a hydrogen flowing-in hole 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a semiconductor manufacturing apparatus, and more particularly to an apparatus for forming a silicon oxide film on the surface of a silicon wafer, in which hydrogen gas is burned to obtain water vapor.

(Prior Art) A conventional apparatus for obtaining water vapor using a hydrogen/oxygen gas combustion method is shown in FIG. In this device, first, the oxygen inlet l
Oxygen is flowed in advance from the combustion chamber IK, and the ignition heater 3 is turned on so that the temperature of the heater 3 becomes higher than the ignition temperature of hydrogen.

Next, hydrogen is caused to flow into the combustion chamber 2 from the hydrogen inlet 4, ignited and combusted by the ignition heater 3 to generate water vapor, and the water vapor is transferred to the process tube 6 in the electric furnace 5.
supply to. A silicon wafer 7 is housed in the process tube 6. This silicon wafer 7 is thermally oxidized while being supplied with the water vapor.

By the way, in the above combustion method, when the flow rate ratio of hydrogen to oxygen is 2:1, combustion occurs slowly;
Hydrogen flame (number 8 in Figure 2 indicates the hydrogen flame)
is relatively low temperature (approximately 1900°C). however,
The hydrogen-oxygen mixture ratio in the combustion chamber 2 varies depending on the oxidation conditions of the silicon wafer, and combustion conditions in an oxygen-rich atmosphere are often required. In that case, the hydrogen flame 8 becomes an oxygen-rich flame. The temperature of Q1 flame will reach 2800℃. When the flame temperature i reaches the cylinder temperature, the quartz in the nozzle part of the hydrogen inlet 4 softens and evaporates, as shown in Figure 3 (
The normal nozzle part shown in a) is deformed as shown in FIG. (Objective of the Invention) This invention is based on the above-mentioned points, and its object is to prevent soft 5L'# generation of quartz at the nozzle part of the hydrogen inlet, and An object of the present invention is to provide a semiconductor manufacturing equipment that can create any atmosphere suitable for oxidation conditions.

(Girder of the Invention) The key point of this invention is that the hydrogen combustion chamber and the mixing chamber for excess oxygen and other non-flammable gases are heated separately.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. It is 0DKJ. In this figure, reference numeral 1 denotes a combustion chamber, an ignition heater 12 is provided on the outer wall, and an oxygen inlet 13 and a hydrogen inlet 14 are opened inside.

Reference numeral 15 denotes a mixing chamber, which is separated from the combustion chamber 11 by a separation plate 16. However, a false hole 17 of about 5 smφ is formed in the separation plate 16 so that the water vapor generated in the combustion chamber 11 is supplied to the mixing chamber 15 through this hole 17. A dilution oxygen inlet 18 opens into the mixing chamber 15 . That is, when the hydrogen flow rate of the hydrogen inlet 14 and the oxygen flow axis ratio of the oxygen inlet 13 are set to 2:], the excess oxygen necessary for oxidizing the silicon wafer, that is, the oxygen that dilutes the water vapor, is Dilution enzyme inlet I
8, only the mixture m<ys flows into Ic h7. The side of the mixing chamber 15 opposite to the separating plate 16 is connected to a process chamber 21'7'9. An electric furnace 20 is provided around the outer periphery of the process tube]9.

Also, a silicon wafer 2 is placed inside this process tube 19.
1 is accommodated.

In the apparatus thus constructed, first, oxygen was introduced through the oxygen inlet 13 and the dilution enzyme inlet 18 to fill the combustion chamber 1 and the mixing chamber 15 with oxygen.
Turn on the ignition heater 12 to reach 600°C, the ignition point of hydrogen.
Do more than that. Next, hydrogen is introduced through the hydrogen inlet 14. The hydrogen that has flowed into the combustion chamber 11 is ignited by the heat of the ignition heater 12 and starts combustion. When combustion of hydrogen is confirmed, the ignition heater 12 is turned off. At this time, the ratio of the hydrogen flow rate from the hydrogen inlet 14 to the oxygen flow rate from the oxygen inlet 13 is set to 2:1, which is the composition ratio of water vapor molecules. Hydrogen combustion at such a flow rate ratio is slow, and the hydrogen flame 22 becomes a relatively low temperature flame of 6D at about 1900°C. The water vapor generated in the combustion chamber 11 by this combustion flows into the mixing chamber 15 through the hole 17 of the separation plate 16, flows into the dilution oxygen inlet 8 and 7' (after being mixed with oxygen, the water vapor flows through the process tube 19 A silicon wafer 21 is housed in the process tube 19.
This silicon wafer 21 is oxidized in the mixed atmosphere of oxygen and water vapor.

As described above, in one embodiment of the present invention, since the combustion chamber 11 and the mixing GLS are separated, an atmosphere suitable for oxidation is supplied, and the amount of hydrogen and oxygen in the combustion chamber 11 is made the same as the composition ratio of water vapor molecules. be able to. In the past, the hydrogen flame 22 could reach a high temperature of 2,800°C, which is the temperature of an oxygen-excess flame, but it can be suppressed to about 1,900°C due to slow combustion. Therefore, soft evaporation of the quartz in the nozzle portion of the hydrogen inlet 14 is prevented, and if the nozzle portion is deformed, impurities in the evaporated quartz may affect the silicon wafer 21, reducing the reliability of the silicon wafer 21. It is possible to eliminate the problem of deterioration.

In the above embodiment, diluted oxygen was mixed with water vapor in the mixing chamber 15, but depending on the oxidation conditions, the mixing chamber 1
The gas mixture in step 5 can be electrolyte or other non-flammable scum.

(Effects of the Invention) As detailed above, according to the apparatus of the present invention, the hydrogen combustion chamber is completely separated from the mixing chamber in which the water vapor and non-flammable scum generated in the chamber are completely mixed. While supplying any atmosphere suitable for IC, deformation of the nozzle and adverse effects on the wafer can be prevented, and stable oxidation can be performed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the half body manufacturing apparatus of the present invention, Fig. 2 is a cross-sectional view of a conventional apparatus, and Fig. 3 shows a nozzle portion of the hydrogen inlet in the conventional apparatus. FIG. 11... Combustion chamber, 12... Ignition heater, 13...
- Oxygen inlet, 14... Hydrogen inlet, 15... Mixing chamber, 16... Separation plate, 17... Hole, 18... Oxygen inlet for dilution. Patent applicant: Okishimoki Kogyo Co., Ltd. Figure 1 2 Figure 2 Figure 3 (0)p

Claims (1)

[Claims] Semiconductor manufacturing characterized by separately providing a combustion chamber that mixes and burns hydrogen gas and oxygen gas to continuously obtain water vapor, and a mixing chamber that mixes the water vapor generated in the nuclear chamber with nonflammable gas. Device.