JP4595152B2 - Vacuum exhaust apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an evacuation apparatus and method used in the manufacture of semiconductor wafers, liquid crystal substrates and the like.
[0002]
[Prior art]
Conventionally, as an example of an evacuation apparatus, a dry etching apparatus for manufacturing a semiconductor wafer, a liquid crystal substrate, or the like is known. FIG. 4 is a diagram showing an exhaust system of a conventional dry etching apparatus. In FIG. 4, reference numeral 1 denotes a reaction chamber where a reaction gas is introduced from a gas stop valve 2 to process a substrate or the like. The following explanation will be given in order. First, the dry pump 3 and the turbo pump 4 are started up. Then, the bypass valve 5 is opened and evacuation is performed by the dry pump 3. Next, when a predetermined switching vacuum degree is detected by the Pirani gauge 6, the main valve 7 and the foreline valve 8 are opened and the vacuum pumping is switched to the turbo pump 4. Then, the manometer isolation valve 9 is opened, and measurement of the degree of vacuum is started with an analog value through the AD converter with the manometer gauge 10. Next, the gas stop valve 2 is opened to introduce the reaction gas into the reaction chamber 1 and the etching process is started.
[0003]
Moreover, what was described in Unexamined-Japanese-Patent No. 10-7008 is disclosed as a semiconductor manufacturing apparatus which prevents Pirani gauge corrosion and destruction (FIG. 5).
[0004]
In FIG. 5, a wafer is carried into the reaction chamber 1 through the gate valve 11, and the reaction gas is introduced into the reaction chamber 1 from the gas introduction pipes 13 and 14 while the wafer is heated by the heater 12, and from the exhaust pipes 15 and 16. Evacuate to produce a film on the wafer. If a corrosive gas is used as the reaction gas at this time, when the corrosive gas is exhausted, the Pirani gauge 6 is exposed to the corrosive gas. Therefore, the branch pipe 17 is connected to the exhaust pipe 16, and the protection valve 18 and the Pirani gauge 6 are connected thereto. Are connected in this order. The protective valve 18 is closed to prevent the corrosive gas from flowing toward the Pirani gauge 6.
[0005]
[Problems to be solved by the invention]
However, in the apparatus shown in FIG. 4, depending on the gas used, the Pirani gauge breaks down in about one week, and the apparatus becomes unusable or the Pirani gauge must be replaced every week. There was a problem that it took time and effort.
[0006]
Further, in the apparatus shown in FIG. 5, in a vacuum exhaust apparatus that performs processing while exhausting corrosive gas by adjusting the pressure of the reaction chamber with a pressure control valve at the rear stage of the reaction chamber, for example, an etching apparatus, a Pirani gauge is used during the processing. It will not be possible. On the other hand, in a device having a normal turbo pump, when the pressure in the upstream stage of the turbo pump always increases, it is necessary to close the main valve from the viewpoint of protecting the turbo pump so that the pressure is not applied to the turbo pump. The Pirani gauge had to be used for the detection, and the protective valve was not used.
[0007]
In view of the above-described conventional problems, an object of the present invention is to provide an evacuation apparatus and method for preventing a Pirani gauge from being damaged while having a turbo pump protection function.
[0008]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a gas stop valve for introducing an introduction gas into a reaction chamber, a Pirani gauge in which a Pirani isolation valve is provided between the reaction chamber, and a manometer isolator between the reaction chamber. possess a manometer gauge provided with a configuration valve, and a turbo pump in which a main valve between the reaction chamber, the two gauges obtained by a configuration disposed with branches in the middle and said reaction chamber is there.
[0009]
With this configuration, when introducing the introduction gas into the reaction chamber, the Pirani isolation valve can be closed so that the Pirani gauge is not exposed to the introduction gas. In addition, if it is determined that it is necessary to detect the pressure with a manometer gauge and then with a Pirani gauge, open the Pirani isolation valve and measure the pressure with the Pirani gauge to determine the need for turbo pump protection. Can do.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0011]
FIG. 1 shows a first embodiment of a vacuum evacuation apparatus according to the present invention. Specifically, FIG. 1 shows an evacuation system of a dry etching apparatus. In FIG. 1, a reaction chamber 1 is a place where a reaction gas is introduced from a gas stop valve 2 to process a substrate or the like (not shown). The turbo pump 4 is connected to the reaction chamber 1 via a main valve 7, and the dry pump 3 is connected to the turbo pump 4 via a foreline valve 8 and is connected to the reaction chamber 1 via a bypass valve 5. It is connected to the. The Pirani gauge 6 is connected to the reaction chamber 1 via a Pirani isolation valve 19, and the manometer gauge 10 is connected to the reaction chamber 1 via a manometer isolation valve 9.
[0012]
FIG. 2 shows a block diagram of the etching method according to the first embodiment of the present invention. In FIG. 2, the control unit 20 detects the gas stop valve from the pressure detected by the Pirani gauge 6 and the manometer gauge 10. 2, the bypass valve 5, the main valve 7, the foreline valve 8, the manometer isolation valve 9, and the Pirani isolation valve 19 are switched.
[0013]
FIG. 3 shows a flow of the etching method according to the first embodiment of the present invention. First, in step S1, the power is turned on. In step S2, the dry pump 3 and the turbo pump 4 are started. In step S3, the bypass valve 5 is opened and the dry pump 3 is evacuated. The pressure in the reaction chamber is detected by the Pirani gauge 6 with the Pirani isolation valve 19 opened. Then, in step S4, it is determined whether or not a predetermined switching pressure has been reached. If so, the main valve 7 and the foreline valve 8 are opened in step S5, and the vacuum pumping is performed by the turbo pump 4. In addition, the manometer isolation valve 9 is opened and the manometer gauge 10 starts the measurement of the degree of vacuum with an analog value through the AD converter. Next, in step S6, the reaction gas is introduced into the reaction chamber 1 by opening the gas stop valve 2, and the Pirani isolation valve 19 is closed to protect the Pirani gauge 6 from the reaction gas. In step S7, the manometer gauge 10 determines whether the pressure in the reaction chamber 1 is equal to or lower than a predetermined value. If it is equal to or lower than the predetermined value, in step S8, it is determined whether etching is finished. If not completed, the process returns to the step S7, and if completed, the Pirani isolation valve 19 is opened in the step S9 to end the series of flows. If it is greater than the predetermined value in the step S7, the Pirani isolation valve 19 is opened in the step S10 and the pressure in the reaction chamber 1 is changed to a predetermined switching pressure in the Pirani gauge 6 in the next step S11. If it is less than the predetermined value, in step S12, the Pirani isolation valve 19 is closed and the process returns to step S7. If it is smaller than the predetermined value, in step S13, The main valve 7 and the foreline valve 8 are closed and the process is terminated.
[0014]
Therefore, with the above configuration, when introducing the reaction gas into the reaction chamber, the Pirani isolation valve can be closed so that the Pirani gauge is not exposed to the reaction gas, the pressure is detected by the manometer gauge, If it is determined that there is a need to detect with the Pirani gauge, the Pirani isolation valve is opened, the pressure is measured with the Pirani gauge, and the need for turbo pump protection can be determined.
[0015]
In the above embodiment, the reaction gas is introduced into the reaction chamber. However, instead of the reaction gas, an introduction gas may be used.
[0016]
【The invention's effect】
As described above, according to the present invention, the gas stop valve for introducing the introduced gas into the reaction chamber, the Pirani gauge provided with the Pirani isolation valve between the reaction chamber, and the manometer isolation between the reaction chamber When the introduction gas is introduced into the reaction chamber, the Pirani isolation valve is closed by providing a manometer gauge provided with a valve and a turbo pump provided with a main valve between the reaction chamber. If the Pirani gauge can be prevented from being exposed to the introduced gas, and if the pressure is detected by the manometer gauge and further detected by the Pirani gauge, it is necessary to open the Pirani isolation valve, Measure the pressure with a Pirani gauge and have the beneficial effect of determining the need for turbo pump protection. It is.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an exhaust system of an etching apparatus according to a first embodiment of the invention. FIG. 2 is a block diagram of an etching method according to the first embodiment of the invention. FIG. 4 is a diagram showing a flow of an etching method according to the first embodiment of the present invention. FIG. 4 is a diagram showing a configuration of an exhaust system of a conventional etching apparatus. FIG. 5 is to prevent corrosion and destruction of a conventional Pirani gauge. Diagram showing configuration of semiconductor manufacturing equipment 【Explanation of symbols】
1 Reaction chamber 2 Gas stop valve 4 Turbo pump 6 Pirani gauge 7 Main valve 9 Manometer isolation valve 10 Manometer gauge 19 Pirani isolation valve

Claims (2)

A gas stop valve for introducing an introduction gas into the reaction chamber, a Pirani gauge having a Pirani isolation valve between the reaction chamber, a manometer gauge having a manometer isolation valve between the reaction chamber, and the reaction evacuation device have a turbo pump provided with a main valve, the two gauges characterized in that it is arranged to branch midway and said reaction chamber between the chamber. 2. A method using an evacuation apparatus according to claim 1, wherein the pressure of the reaction chamber is detected with a Pirani gauge by opening a Pirani isolation valve; and the reaction chamber is opened with a Manometer gauge by opening a Manometer isolation valve. Detecting the pressure of the gas, opening the gas stop valve to introduce the introduced gas into the reaction chamber and closing the Pirani isolation valve, and the pressure detected by the manometer gauge becomes a predetermined value or more. A vacuum evacuation method comprising: opening the Pirani isolation valve and detecting the pressure with the Pirani gauge.

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