JP2000258309A - Programmed-temperature desorption gas analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To analyze a sample with high sensitivity and efficiently in a high vaccum by a method wherein a sample takeout chamber is isolated from a heating chamber and the air by using a valve in the lower part of the heating chamber. SOLUTION: In a load lock chamber 21, a turbo-molecular pump 11 and a rotary pump 12 are connected so as to be evacuated, and a sample introduction plate 4 moves a sample 34 to a sample stage 2 in a heating chamber 22, In the heating chamber 22, the sample 34 is irradiated with infrared rays via a transparent quartz rod 1, the temperature of the sample 34 is raised, and a discharged gas is measured by a mass spectrometer 9. The sample 24 after its measurement is dropped into a sample takeout chamber 30 by a sample movement mechanism 5 by opening a gate valve 31. Then, the gate valve 31 is closed, a sample discharge valve 32 is opened, and the sample 34 is taken out. At this time, since the sample takeout chamber 30 can be isolated from the heating chamber 22 and the air by using both valves 31, 32, a sample which is to be measured next can be evacuated preliminarily in the load lock chamber 21, and the sample 34 can be measured in a high vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermal desorption gas analyzer. In particular, it relates to a sample introduction stage structure and a sample exchange method.

[0002]

2. Description of the Related Art A thermal desorption gas analyzer is a device for analyzing a gas released when a sample is heated in a vacuum by a mass spectrometer. Conventionally, as this type of device,
"Vacuum, Vol. 34, No. 11, pp. 813-819 (1
991)). Since the load lock system is adopted, the outside air is not directly introduced into the heating section, the influence of degassing from the sample stage can be suppressed, and the heating chamber can be set to 10 ^-9 T in a shorter time.
orr can be reached.

FIG. 7 is a configuration diagram of a conventional thermal desorption gas analyzer. The load lock chamber 21 connects the nitrogen purge valve 19 and the sample exchange port 18, and
It has a sample introduction plate 4 and has a turbo molecular pump (TM
P) 11 and a rotary pump (RTP) 12 are connected to exhaust air. A vacuum gauge (VG) 20 is provided in the load lock chamber 21. The sample introduction plate 4 is configured to transfer a sample from the load lock chamber 21 to the sample stage 2 by a sample introduction device (not shown).
Can be moved to The heating chamber 22
Are separated by a gate valve 17 and include a transparent quartz rod 1, a sample stage 2, and a sample moving mechanism 5. The transparent quartz rod 1 is connected to an infrared heating unit 13 for heating a sample, a temperature controller 14, and a computer 16. In addition, a turbo molecular pump (TMP) 7 and a rotary pump (RTP) 8 are connected to perform exhaust. Further, a mass spectrometer 9 for measuring desorbed gas is connected.

As shown in FIG. 7, a sample 3 for measurement is set on a sample stage 2. The degree of vacuum outside the sample 3 is typically 1 × 10 ⁻⁸ Torr or less, and the gas released into the vacuum during heating can be measured by the mass spectrometer 9.

The movement of the sample 3 to the sample stage 2 is performed as follows. FIG. 8 is a perspective view of a sample introduction plate for moving a sample to a sample stage. FIG. 9 is an explanatory diagram of a method of moving the sample from the sample introduction plate to the sample stage.

After purging the load lock chamber 21 with N ₂ , the sample 3 is placed on the sample introduction plate 4 and evacuated. After the ultimate vacuum reaches 1 × 10 ⁻⁵ Torr or less, the sample introduction plate 4 is moved to the heating chamber 22. Then, after moving the sample moving mechanism 5 to a predetermined position, the claw 6 of the sample moving mechanism 5 is lowered in the Fa direction to a height corresponding to the sample 3. Further, the sample 3 is set on the sample stage 2 by moving the sample moving mechanism 5 in the direction of the sample stage 2 (Fb direction). Then, the sample 3 is heated by irradiating infrared rays through the transparent quartz rod 1 for introducing infrared rays, and the gas released at that time is measured by the mass spectrometer 9.

FIG. 10 is an explanatory view of a method of moving a sample from the sample stage 2 to the sample introduction plate 4. First, the sample introduction plate 4 is inserted into the heating chamber 22 (see FIG. 7). Next, after moving the sample moving mechanism 5 to a predetermined position, the claw 6 of the sample moving mechanism 5 is lowered in the Fa direction to a height corresponding to the sample 3. Further, the measured sample 3 is set on the sample introduction plate 4 by moving the sample moving mechanism 5 in the direction of the sample introduction plate 4 (Fc direction). The sample introduction plate 4 is returned into the load lock chamber, the gate valve 17 is closed, the load lock chamber 21 is purged with N _2, and then the measured sample 3 is taken out from the sample exchange port 18. Next, the sample before measurement is placed on the sample introduction plate 4 and the sample analysis is repeated.

By using the above-described sample introduction method, the degree of vacuum in the heating chamber 22 can always be kept at 1 × 10 ⁻⁷ Torr or less.

[0009]

However, in the above-mentioned conventional thermal desorption gas analyzer, when performing a continuous measurement, after the measured sample is returned to the load lock chamber, the load lock chamber is once set to N. _{(2) It} is necessary to purge and remove the measured sample, then set the sample before measurement on the sample introduction plate, evacuate the load lock chamber, and insert the sample before measurement into the heating chamber. Therefore, the next measurement sample cannot be evacuated in the load lock chamber simultaneously with the measurement.

In view of the circumstances described above, an object of the present invention is to provide a thermal desorption gas analyzer capable of efficiently performing high-sensitivity analysis under a high vacuum.

[0011]

The thermal desorption gas analyzer according to claim 1 of the present invention is a thermal desorption gas analyzer having a load lock chamber and a heating chamber, wherein the thermal desorption gas analyzer includes a load lock chamber and a heating chamber. A heating chamber and a sample removal chamber capable of being isolated from the atmosphere are provided by two valves provided at a lower part of the chamber.

Further, in the thermal desorption gas analyzer according to claim 2 of the present invention, the slope for preventing the measured sample put into the sample removal chamber from falling out of the sample removal chamber is provided with the slope. It is provided in a heating chamber.

A thermal desorption gas analyzer according to a third aspect of the present invention is to temporarily store a measured sample between a lower portion of a sample stage in the heating chamber and an upper portion of the sample removal chamber. Characterized in that it comprises a receiving member that rotates in the vertical direction.

A thermal desorption gas analyzer according to a fourth aspect of the present invention is a thermal desorption gas analyzer having a load lock chamber and a heating chamber.
A sample introduction device that moves the sample from the load lock chamber onto the sample stage includes a sample introduction plate capable of loading both a pre-measurement sample and a measured sample,
It is characterized in that a sample removal and a sample insertion are performed simultaneously by the sample introduction plate.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thermal desorption gas analyzer according to the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a configuration diagram showing a first embodiment of a thermal desorption gas analyzer according to the present invention. As shown in FIG. 1, the thermal desorption gas analyzer to which the present invention is applied is of a load lock type, is composed of a load lock chamber 21 and a heating chamber 22, and is separated by a gate valve 17. The load lock chamber 21 connects the nitrogen purge valve 19 and the sample exchange port 18, has the sample introduction plate 4, and has a turbo molecular pump (TMP).
11 and a rotary pump (RTP) 12 are connected to exhaust air. A vacuum gauge (VG) 20 is provided in the load lock chamber 21. The sample introduction plate 4 can move a sample from the load lock chamber 21 to the sample stage 2 by a sample introduction device (not shown).

The heating chamber 22 has a transparent quartz rod 1, a sample stage 2, and a sample moving mechanism 5, and has a sample removal chamber 30 at the lower part. A gate valve 31 is provided between the heating chamber 22 and the sample removal chamber 30, and a sample disposal valve 32 is provided between the sample removal chamber 30 and the outside of the apparatus so as to be shielded from each other. It has become. The sample removal chamber 30 has a structure capable of evacuating by a turbo pump (TMP) 11 and a rotary pump (RTP) 12 and purging N ₂ from a nitrogen leak valve 33. Further, an infrared heating unit 13 for heating a sample, a temperature controller 14 and a computer 16 are connected to the transparent quartz rod 1.

The thermal desorption gas analyzer of this embodiment is
The sample 34 is heated by irradiating infrared rays through the transparent quartz rod 1 for introducing infrared rays, and the gas released at that time is measured by the mass spectrometer 9.

As shown in FIG. 2A, after the measurement is completed, the sample 34 is first opened with the gate valve 31 opened.
The claw 6 of the sample moving mechanism 5 is pressed against the measured sample 34 to move the measured sample 34 in the direction of the sample removal chamber 30. Next, the measured sample 34 is dropped from the sample stage 2, and the measured sample 34 is loaded into the sample removal chamber 30. Thus, the measured sample 34 can be discarded without passing through the load lock chamber 21.

Next, as shown in FIG. 2B, in order to remove the measured sample 34 from the sample removal chamber 30, the gate valve 31 is first closed and then the sample removal chamber 30 is purged with N ₂ . Next, the sample disposal valve 32 is opened, and the measured sample 34 in the sample removal chamber 30 is taken out. The sample removal chamber 30
Can store a plurality of measured samples 34, so that the measured samples 34 need not be taken out of the apparatus for each measurement.

In this embodiment, since the two valves, ie, the gate valve 31, the sample disposal valve 32, and the sample removal chamber 30 are provided, the measured sample 34 can be removed without passing through the load lock chamber 21. In addition to this, the next measurement sample can be pre-evacuated in the load lock chamber 21 simultaneously with the measurement.

In the thermal desorption spectrometer configured as described above, by performing preliminary evacuation of the next measurement sample in the load lock chamber at the same time as the measurement, the preliminary evacuation time can be lengthened, whereby the load lock chamber can be extended. Can be achieved without time loss.

Therefore, when the next measurement sample is inserted into the heating chamber, a decrease in the degree of vacuum in the heating chamber is suppressed, and high-sensitivity measurement under a high vacuum can be performed as compared with the conventional thermal desorption gas analyzer. You can do it without wasting time. As a result, high-sensitivity analysis in a high vacuum can be realized more efficiently.

Second Embodiment In the structure shown in the first embodiment, the measured sample 34
It is necessary to set the sample removal chamber 30 at the falling position of the sample. Therefore, the installation position of the sample extraction chamber 30 and the inner diameter of the gate valve 31 can be restricted.

Therefore, in the present embodiment, as shown in FIG. 3, a slope 35 is provided above the sample removal chamber 30. By providing such a slope 35, the measured sample 34 is
It can be prevented from falling out of zero. In addition, since the slope 35 is provided, the dropped measured sample 34 is reliably guided to the sample removal chamber 30 along the slope 35, so that the sample removal chamber 30 is installed at an arbitrary place. be able to.

Embodiment 3 FIG. 4 is a block diagram showing another embodiment of the thermal desorption gas analyzer of the present invention. In the present embodiment, the receiver 36 is attached to the upper part of the sample removal chamber 30, and the measured sample 34 is dropped on the receiver 36 using the sample moving mechanism 5 and temporarily stored. The measured sample 34 collected on the receiving member 36 can be dropped into the sample removal chamber 30 by rotating the receiving member 36 in the Sa direction.

Therefore, in the present embodiment, measurement is performed with the gate valve 31 closed, and when taking out a sample,
The gate valve 31 is opened. Next, the receiver 36 is rotated to move the plurality of measured samples 34 to the sample removal chamber 30. Next, after the gate valve 31 is closed, the inside of the sample removal chamber 30 is leaked with N ₂ . Next, the sample disposal valve 32 is opened, and the measured sample 34 can be taken out.

The receiving device 36 is not particularly limited in the present invention as long as it can easily store the measured sample 34 and can move smoothly into the sample extracting chamber 30. As shown in FIG. 5A, a V-shaped receiver having an opening in the rotation direction Sa can be provided. Alternatively, as shown in FIG. 5B, a conical receiver having an opening in the rotation direction Sa can be used. FIG. 5A or FIG.
By using the receiving device of (b), the measured sample 34 dropped by the sample moving mechanism 5 can be guided onto the receiving device 36 and can be prevented from falling out of the receiving device 36.

In the present embodiment, by using the receiver 36, the measurement can be performed with the gate valve 31 between the sample removal chamber 30 and the heating chamber 22 closed. Can be prevented from lowering the degree of vacuum in the heating chamber 22 due to opening.

Embodiment 4 Another thermal desorption gas analyzer according to the present invention will be described. In the present embodiment, as shown in FIG. 6, the sample introduction plate 4 includes a sample insertion plate 37, a sample removal plate 38, a frame 40 connecting the two plates 37 and 38, and a frame 40. And an operating mechanism (not shown) for operating. First, as shown in FIG. 6A, the next measurement sample (sample before measurement) 39 is placed on the sample insertion plate 37, and the sample removal plate 38 is inserted into the heating chamber in an empty state. Next, the sample removal plate 38 is placed in a state of being in contact with the sample stage 2, and the measured sample 34 is placed on the sample removal plate 38 by the sample moving mechanism. Then, as shown in FIG. 6 (b), the frame 40 is rotated downward by the operating mechanism to lower the sample removing plate 38 below the sample inserting plate 37, and then the sample introducing device introduces the sample. The plate 4 is advanced. Then, the sample insertion plate 37 is brought into contact with the sample stage 2, and
The next measurement sample 39 is moved onto the sample stage 2 by the sample moving mechanism 5.

In the present embodiment, the use of the sample introduction plate 4 shown in FIG. 6 allows simultaneous insertion and removal of a sample from the heating chamber.

[0032]

As described above, in the thermal desorption gas analyzer according to the first aspect of the present invention, the heating chamber and the atmosphere can be isolated from each other by the two valves provided below the heating chamber. Since the sample extraction chamber is provided, the next measurement sample 39 can be preliminarily evacuated in the load lock chamber simultaneously with the measurement, and the measurement in a high vacuum can be realized without time loss. As a result, high-sensitivity analysis under high vacuum can be performed efficiently.

In the thermal desorption gas analyzer according to a second aspect of the present invention, the slope for preventing the measured sample placed in the sample removal chamber from falling out of the sample removal chamber is heated. Since it is provided in the chamber, it is possible to prevent the measured sample from falling out of the sample removal chamber.

In the thermal desorption gas analyzer according to a third aspect of the present invention, the measured sample is temporarily stored between a lower portion of the sample stage in the heating chamber and an upper portion of the sample removal chamber. The receiver is rotated vertically so that the measurement can be performed with the gate valve closed between the sample removal chamber and the heating chamber. A decrease in the degree of vacuum can be prevented.

Further, in the thermal desorption gas analyzer according to a fourth aspect of the present invention, the sample introduction device for moving the sample from the load lock chamber onto the sample stage is capable of loading both the pre-measurement sample and the measured sample. Since the sample introduction plate is provided, sample removal and sample insertion can be performed simultaneously by the sample introduction plate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a thermal desorption analyzer according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a sample removal method in the thermal desorption gas analyzer according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram showing a heating chamber in a thermal desorption gas analyzer according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram showing a heating chamber in a thermal desorption gas analyzer according to a third embodiment of the present invention.

FIG. 5 is a perspective view showing an example of a receiver in FIG. 4;

FIG. 6 is a diagram illustrating a configuration of a sample introduction plate and a sample replacement method according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram illustrating an example of a conventional thermal desorption gas analyzer.

8 is a configuration diagram showing a sample introduction plate of the thermal desorption gas analyzer in FIG.

9 is a diagram illustrating a method of moving a sample from a sample introduction plate to a sample stage in the thermal desorption gas analyzer in FIG.

10 is a diagram illustrating a method of moving a sample from a sample stage to a sample introduction plate of the thermal desorption gas analyzer in FIG.

[Explanation of symbols]

Reference Signs List 1 transparent quartz rod, 2 sample stage, 4 sample introduction plate, 5 sample moving mechanism, 6 claws, 9 mass spectrometer, 11 turbo molecular pump, 12 rotary pump, 13 infrared heating unit, 14 temperature control device,
16 computer, 17 gate valve, 18 sample exchange port, 19 nitrogen purge valve, 20 vacuum gauge, 21 load lock chamber, 22 heating chamber, 30 sample removal chamber, 31 gate valve, 32 sample disposal valve, 33 nitrogen leak valve,
34 measured sample, 35 slope, 36 holder,
37 sample insertion plate, 38 sample removal plate, 39th measurement sample (sample before measurement).

Claims (4)

[Claims] 1. A thermal desorption gas analyzer comprising a load lock chamber and a heating chamber, wherein the heating chamber and the atmosphere are isolated from each other by two valves provided below the heating chamber. Temperature desorption gas analyzer equipped with a sample removal chamber capable of performing pressure reduction. 2. The thermal desorption according to claim 1, wherein a slope for preventing a measured sample put into the sample removal chamber from falling out of the sample removal chamber is provided in the heating chamber. Gas analyzer. 3. A method according to claim 1, wherein a portion between a lower portion of the sample stage in the heating chamber and an upper portion of the sample removing chamber is provided.
3. The thermal desorption spectrometer according to claim 1, further comprising a vertically rotating receiver for temporarily storing the measured sample. 4. A thermal desorption gas analyzer comprising a load lock chamber and a heating chamber, wherein the sample introduction device for moving a sample from the load lock chamber onto a sample stage comprises: A thermal desorption gas analyzer equipped with a sample introduction plate capable of loading both of a finished sample and simultaneously taking out and inserting a sample with the sample introduction plate.