JPH0429402Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an exhaust system for an X-ray photoelectron spectrometer to create a vacuum between an analysis chamber and an X-ray source chamber in the X-ray photoelectron spectrometer. It is something.

(b) Prior Art In this type of conventional device, when a voltage is applied to an anode and a filament disposed in an X-ray source chamber to generate X-rays, vaporized substances are released from the anode and filament. In order to prevent this evaporated material from adhering to the sample surface in the analysis chamber and making it impossible to detect the true analysis information on the sample surface, X-rays are applied to the analysis chamber where the sample is placed and the sample. The X-ray source chamber that generates X-rays for irradiation is connected to an exhaust system in which a main pump for forming an ultra-high vacuum and an auxiliary pump for rough evacuation to form a certain degree of vacuum are connected in series. The configuration is such that they are connected individually.

In general, in an X-ray photoelectron spectrometer,
Of the X-rays, thermionic electrons, secondary electrons, etc. emitted from the anode and filament in the X-ray source chamber, only the X-rays are transmitted to the analysis chamber and irradiated onto the sample, while other thermionic electrons are not transmitted. A very thin aluminum foil is placed on the side of the X-ray source room facing the analysis room. When creating a vacuum between the X-ray source chamber and the analysis chamber covered with aluminum foil, the analysis chamber and the X-ray source chamber are pressure-isolated by the aluminum foil. When the vacuum pump exhaust system installed separately in the radiation source room is operated, due to the performance difference of the vacuum pump exhaust system and the difference in volume between the analysis room and the X-ray source room, There will be a pressure difference between the chamber side and the aluminum foil, which may break the aluminum foil.

Therefore, conventionally, when operating the vacuum pump exhaust system that is separately connected to the analysis room and the X-ray source room, initial evacuation is performed by communicating the bypass connected to the analysis room and the X-ray source room. When a certain degree of vacuum was created, the bypass was shut off by a valve or the like, and then the main pump was started to create an ultra-high vacuum.

When operating such a vacuum pump exhaust system, there is a drawback that it is troublesome to connect the bypass during initial pumping and to shut off the bypass before starting the main pump. Since the pumps were connected one by one, there was a disadvantage that the manufacturing cost was high.

(c) Purpose The present invention solves the drawbacks of the prior art described above, and is a first method for forming an ultra-high vacuum that is connected separately to the analysis chamber and the X-ray source chamber in an X-ray photoelectron spectrometer. The back pressure sides of the main pump and the second main pump are combined and connected to the third pump, which is an auxiliary pump, so as to communicate with the third pump, and a valve for introducing atmospheric air is connected to the communication part to create a vacuum. It is an object of the present invention to provide an exhaust device for an X-ray photoelectron spectrometer that prevents aluminum foil from being torn during formation or return to atmospheric pressure and that simplifies operability during vacuum formation.

(d) Configuration The present invention performs analysis by connecting a third pump to the back pressure side of the first main pump and second main pump, which are individually connected to the analysis room and the X-ray source room. Since the chamber side and the X-ray source chamber side are in pressure communication, the aluminum foil interposed between the analysis chamber and the X-ray source chamber is not broken when creating a vacuum or returning to atmospheric pressure. Moreover, the operation during vacuum formation can be simplified.

(E) Embodiment An embodiment of the exhaust system for an X-ray photoelectron spectrometer according to the present invention will be described with reference to FIG.

In the figure, 1 is an analysis room, and 2 is an X-ray source room. In the X-ray source chamber 2, a filament 6 and an anode 5 are provided, and an excitation voltage source 7 is connected between the filament 6 and the anode 5 with the polarity shown. heated filament 6
Thermionic electrons emitted from the anode collide with the anode 5, and secondary electrons, X-rays, etc. are generated at this time.
It is covered with 2μ aluminum foil 8. This aluminum foil 8 has the function of allowing only X-rays to pass through to the analysis chamber 1 side, but not allowing thermoelectrons and evaporated substances generated from the filament 6 and anode 5 to pass through. The X-ray source chamber 2 is connected via a pipe 3 to a turbo molecular pump 4 for forming an ultra-high vacuum, which is a first main pump.

In the analysis room 1, a sample 9 to be irradiated with X-rays transmitted through an aluminum foil 8 is placed on a sample support stand 10.
It is placed on.

Although this sample support stand 10 is shown schematically, it is actually a turntable (not shown) placed in the analysis chamber 1 or a sample support stand (not shown) installed in the analysis room 1. It is arranged through a hole.

A turbo molecular pump 12 is a second main pump, and is connected to the analysis chamber 1 via a pipe 11. The evacuation capacity of the turbo-molecular pump 12, which is the second main pump, is greater than that of the turbo-molecular pump 4, which is the first main pump. The back pressure sides of the turbomolecular pumps 4 and 12 are connected to pipes 13 and 14, respectively, and are jointly connected to a third auxiliary pump 17, which is a rotary pump for vacuum roughing, through a pipe 15. It is connected. Note that a valve 16 for introducing atmospheric pressure is provided on the side of the pipe 15. This valve 16 is closed when a vacuum is created, but is opened when the analysis chamber 1 and the X-ray source chamber 2 are returned to atmospheric pressure.
The atmosphere introduced by 6 is introduced into the X-ray source chamber 2 via pipe 14, turbomolecular pump 4, and pipe 3, and is also introduced into X-ray source chamber 2 through pipe 13, turbomolecular pump 12,
It is introduced into the analysis chamber 1 via a pipe 11.

To explain the operation of the device configured in this way, first, during the initial evacuation, the rotary pump 17
is activated, and the air present in the analysis chamber 1 and the Exhaust via molecular pump 4 and pipes 14 and 15. During this initial evacuation, the evacuation system is formed by only one rotary pump 17, and the analysis chamber 1 and the X-ray source chamber 2 are communicated with the rotary pump 17 via the pipes 13 and 14. No pressure difference is created in the pressure applied to the aluminum foil 8 interposed between the analysis chamber 1 and the X-ray source chamber 2. Initial evacuation is performed in this way, and when the pressure in the analysis chamber 1 and the X-ray source chamber 2 reaches approximately 10 ^-2 Torr, the rotary pump 17 remains driven and the turbomolecular pumps 4 and 12 are activated. Activate it and create an ultra-high vacuum inside them.

In this case, turbomolecular pumps 4 and 12
Even if a slight pressure difference occurs due to the difference in the capacity of the analysis chamber 1 and the conductance of the exhaust system between the analysis chamber 1 and the pump 12, pipe 13,
Pipe 15, rotary pump 17, pipe 3, turbo molecular pump 4, pipe 14, pipe 1
Since the aluminum foil 8 is in communication with the rotary pump 17, the difference in pressure applied to the aluminum foil 8 is small.
will never be torn.

Next, when returning the analysis chamber 1 and the X-ray source chamber 2 to atmospheric pressure, the valve 16 is opened to introduce air, but even in this case, the analysis chamber 1 and the X-ray source chamber 2 are Since the exhaust system of the aluminum foil 8 is in communication with the aluminum foil 8, there is no pressure difference that would cause the aluminum foil 8 to break.

In addition, in the description of the embodiment of the present invention, the back pressure side of the turbomolecular pump, which is individually connected to the analysis chamber 1 and the X-ray source chamber 2, is connected in pressure communication with a rotary pump that is an auxiliary pump. In the exhaust system of this configuration, for example, a diffusion pump or the like can be used instead of the turbo molecular pump for forming an ultra-high vacuum.

(F) Effect As explained above, according to the present invention, the back pressure side of the first main pump and second main pump for ultra-high vacuum formation, which are individually connected to the analysis room and the X-ray source room, is They are combined together and connected to a third pump that is an auxiliary pump to provide pressure communication between the analysis chamber side and the X-ray source chamber side,
Furthermore, since the structure is equipped with a valve for introducing atmospheric pressure, the aluminum foil will not be broken when creating a vacuum or returning to atmospheric pressure. There is no need to operate the opening/closing control of the bypass connected to the radiation source room side, and the third pump is connected to the first main pump and the second main pump. It has the advantages of easy operation and low manufacturing cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an exhaust system for an X-ray photoelectron spectrometer according to the present invention. In the figure, 1 is the analysis room, 2 is the X-ray source room, 3, 11,
13, 14, 15 are pipes, 4 and 12 are turbo molecular pumps, 5 is an anode, 6 is a filament, 7
1 is an excitation voltage source, 8 is an aluminum foil, 9 is a sample, 10 is a sample support stand, 16 is an atmospheric pressure introduction valve, 1
7 indicates a rotary pump.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a device comprising an analysis chamber and an X-ray source chamber provided with aluminum foil on the side facing the analysis chamber, ultra-high vacuum forming connected to the X-ray source chamber a first main pump for ultra-high vacuum formation connected to the analysis chamber, and a communication section on the back pressure side between the first main pump and the second main pump described above. An exhaust device for an X-ray photoelectron spectrometer, comprising: a third pump for forming a vacuum; and a valve for introducing atmospheric pressure connected to the communication portion. (2) The exhaust system for an X-ray photoelectron spectrometer according to claim 1, wherein the first main pump and the second main pump are turbomolecular pumps or diffusion pumps.