JPH0237103Y2 - - Google Patents

Description

[Detailed description of the invention] This invention detects the leakage of silane gas or the occurrence of a fire during the manufacturing process at a VLSI factory, etc., and appropriately controls disaster prevention devices such as fire extinguishers and the manufacturing process. This relates to alarm and control devices in semiconductor factories and the like.

Semiconductor factories, such as those for ultra-LSIs, which have made great strides in recent years, use silane gas when forming insulating films on silicon wafers, but such processing gases are toxic and can be dangerous if the concentration exceeds 2-5%. It is dangerous because it reacts with oxygen in the air and ignites and burns, and a fire thought to have been caused by these gases broke out at a super LSI factory, resulting in minor damage.

In consideration of the above points, this device immediately detects the state in which leaked silane gas reacts with oxygen in the air, combusts, and generates combustion products, and performs appropriate control in advance or at the initial stage of a fire. It provides alarm and control equipment for semiconductor factories and other facilities that can perform

Hereinafter, a case where an embodiment of this invention is applied to a CVD apparatus (Chemical Vapor Deposition) used for forming an insulating film on a semiconductor wafer and its peripheral equipment will be described with reference to the drawings.

In FIG. 1, 1 is a silane gas cylinder, 2 is an ammonia gas cylinder, 3 is a storage box for storing these cylinders, and 6 is a nitride film forming unit that supplies silane gas and ammonia gas through pipes 4 and 5 to form an insulating film on a semiconductor wafer. A device (CVD), 8 is a detoxification device that supplies oxygen to the unreacted silane gas flowing out from the device 6 through the pipe 7 to force an oxidation reaction, that is, a combustion process; 10 is a detoxification device 8;
A detection box 12 is installed between the pipes 9 to monitor the state of the gas discharged into the exhaust duct 11.
13 is a vacuum pump that evacuates the inside of the forming apparatus 6; 13 is an exhaust port that exhausts indoor air; and 14 is a damper provided in a pipe 15 connecting the storage box 3 and the exhaust duct 11. Furthermore, the storage box 3 and the detection box 10 are provided with fire detectors D ₁ and D ₂ that detect combustion products produced when silane gas leaks, reacts with oxygen in the air, and burns. In this case, photoelectric smoke detectors and ionization smoke detectors can be used as fire detectors to detect combustion products; the vertical axis shows the output of each sensor, and the horizontal axis shows the concentration of silane gas combustion products. According to the characteristic curve diagram shown in FIG. 3, the ionization type smoke detector b is more sensitive to the combustion products of silane gas than the photoelectric type smoke detector a, and can detect the occurrence of the combustion products earlier. Further, as shown in FIG. 2, the above-mentioned detectors D ₁ and D ₂ are connected directly to the fire detector D ₁ installed in the storage box 3, and directly connected to the fire detector D ₂ installed in the detection box 10, as shown in FIG. It is connected to the OR circuit OR through the OR circuit, and its output is connected to a disaster prevention device such as a fire alarm or fire extinguisher, or a relay device (not shown) that appropriately controls the semiconductor manufacturing process.

Next, the operation of the above device will be explained. In the nitride film forming apparatus 6, a semiconductor wafer is placed therein, the vacuum pump 12 is used to create a vacuum, and then the silane gas cylinder 1 and the ammonia gas cylinder 2 are opened to supply silane gas and ammonia gas to the apparatus 6 to form the nitride film necessary for the semiconductor wafer. A nitride film, that is, an insulating film is generated. Further, the treated gas containing unreacted gas is forcibly subjected to an oxidation reaction in the abatement device 8 and is discharged from the exhaust duct 11 through the piping 9 as a safe gas.

On the other hand, in such a situation, when the silane gas from the silane gas cylinder 1 reacts with oxygen in the air and burns, the combustion product activates the fire detector D ₁ , and an unplanned fire alarm or fire extinguishing system is activated via the OR circuit OR. A disaster prevention device such as the above or a relay device that controls this manufacturing process is operated, such as by fully opening the damper 14 and releasing the leaked gas into the duct 11. In addition, in the detection box 10, the abatement device 8
is in normal operation, the combustion products incinerated through pipe 9 are discharged through pipe 9 to exhaust duct 1.
1, the fire detector _D2 detects the combustion products and operates, but its output is output from the inverter I.
Since it is inverted by , nothing is input to the OR circuit OR, and the OR circuit OR does not operate. However, when the abatement device 8 malfunctions and untreated silane gas is released and no combustion products are generated, the fire detector D ₂ becomes inoperable, but its output is reversed by the inverter I and an output is generated. Therefore, through the OR circuit OR, disaster prevention devices such as fire alarms and fire extinguishing devices (not shown) or relay devices that control the manufacturing process are operated.

As mentioned above, this idea can be applied to semiconductor manufacturing processes, etc.
Fire detectors are installed at locations where toxic and flammable silane gas is used as a processing gas to detect combustion products from the combustion of this gas.
This has the effect of providing an alarm and control device for semiconductor factories and the like that can perform appropriate control in advance or at the initial stage of a fire.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of this invention, FIG. 2 is a circuit diagram thereof, and FIG. 3 is a characteristic curve diagram of a photoelectric smoke detector and an ionization smoke detector. 1...silane gas cylinder, 3...storage box, 6...
...Nitride film forming device, 8...Abatement device, 10...Detection box, 11...Exhaust duct, _D1 , _D2 ...Fire detector for detecting combustion products.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. When toxic and flammable silane gas is used as a processing gas such as in the semiconductor manufacturing process and is removed by incineration, the silane gas leaks and reacts with oxygen in the air and burns. Alarm and control in semiconductor factories, etc., characterized in that a fire detector is installed to detect combustion products generated, and a change in the output of this detector is used to issue an alarm and control disaster prevention equipment such as a fire extinguisher and semiconductor manufacturing processes. Device. 2. Alarm and control in semiconductor factories, etc. as set forth in Claim 1 of the Utility Model Registration Claim, in which a fire detector equipped with an inverter on the output side is installed on the secondary side of a pollution abatement device that burns used silane gas. Device. 3 Claim No. 1 for Utility Model Registration in which a fire detector is installed in a storage box containing silane gas cylinders
Alarm and control devices in semiconductor factories, etc., as described in Section 2. 4. An alarm and control device for a semiconductor factory or the like as set forth in any one of claims 1 to 3 of the utility model registration claim, wherein the fire detector is an ionization smoke detector.