JPH0545310A - X-ray monochrometer - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent a decrease in detection sensitivity and shorten the adjustment time. [Structure] A shutter that can be opened and closed so that it can be driven from the atmosphere side to cover the dispersive crystal is provided, and at the time of bakeout or ion etching, the dissociative crystal is covered by the shutter to shield the radiant heat from the heater and scatter from the sample by etching. To prevent the attachment of the element. Further, by providing a fluorescent plate on one surface of the shutter and adjusting the X-ray source and the slit position by visually observing the light of the fluorescent plate through the observation window during the adjustment work, it is possible to greatly reduce the adjustment work time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray monochromator for irradiating a sample with a monochromatic X-ray to excite it and detecting and analyzing photoelectrons emitted from the sample.

[0002]

2. Description of the Related Art When an X-ray monochromator is used in a photoelectron spectrometer, as shown in FIG. 3, X-rays 15 from an X-ray generator 1 are attached to a pedestal 3 through a slit 20 to form a dispersive crystal (SiO 2). ₂ ) and extract the X-ray with a predetermined diffraction angle from the surface of the dispersive crystal to make it monochromatic,
This monochromatic X-ray is applied to the sample 6 supported on the sample table 5, and the photoelectrons emitted from the sample are detected by the detector 7. The detector 7 is usually configured to lead to a mass spectrometer through an entrance lens.

[0003]

The dispersive crystal used for monochromatic excitation X-ray in such an X-ray monochromator is made of SiO ₂ having a thickness of about 0.1 mm.
As shown in FIG. 3, it is attached to the pedestal 3. On the other hand, the device is baked out because it is necessary to make an ultra-high vacuum of about 1 × 10 ^-10 Torr, but the radiant heat at this time causes the bonded surface of the dispersive crystal to peel off or the surface of the dispersive crystal to wavy. As a result, the accuracy of the crystal plane made to have the same size as the Roland circle was lowered, resulting in a decrease in detection sensitivity. Further, in the photoelectron spectrometer, the sample surface is etched by an ion beam as a pretreatment of the sample. At this time, scattered elements adhere to the surface of the dispersive crystal and cause a decrease in detection sensitivity. There is.

Further, the X-ray generator 1, the dispersive crystal 4, the sample 6
Must be arranged on a Rowland circle having a constant center diameter, and in order to effectively irradiate the X-ray generated by the X-ray generator 1 onto the dispersive crystal plane, the X-ray generator 1 and the slit 2
The position is adjusted by moving 0, and if the positional relationship between them is deviated, the detection sensitivity is lowered. However, these adjustments have to be performed in an ultra-high vacuum container, and since X-rays are invisible, the adjustment work requires a high level of skill and a long time. The present invention is intended to solve the above problems, and an object of the present invention is to provide an X-ray monochromator capable of preventing a decrease in detection sensitivity and shortening the adjustment time.

[0005]

SUMMARY OF THE INVENTION The present invention uses X from an X-ray source.
In a photoelectron spectrometer that guides a beam to a dispersive crystal and detects a photoelectron by exciting a sample with X-rays monochromated by the dispersive crystal, a shutter that covers the surface of the dispersive crystal is provided, and the shutter is opened and closed from the atmosphere side. Further, the present invention is characterized in that the shutter is provided with a fluorescent plate, and when the dispersive crystal is covered with the shutter, the fluorescent plate is irradiated with X-rays from the X-ray source.

[0006]

According to the present invention, a shutter which can be opened and closed by driving from the atmosphere side to cover the dispersive crystal is provided, and the dissociated crystal is covered with the shutter at the time of bakeout or ion etching, thereby shielding the radiant heat from the heater. In addition, the element that scatters from the sample due to etching is prevented from adhering. Further, a fluorescent plate is provided on one side of the shutter so that the X-ray from the X-ray source hits the fluorescent plate when the dispersive crystal is covered, and the X-ray source is arranged on the Rowland circle or the slit is moved. By performing the work while visually observing the light of the fluorescent screen through the observation window, it is possible to significantly reduce the adjustment work time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment of the X-ray monochromator of the present invention. In the figure, 1 is an X-ray generator, 2 is a support member, 3 is a pedestal, 4 is a dispersive crystal, 5 is a sample stage, 6 is a sample,
7 is a detector, 9 is a bakeout sheath heater, 10 is an etching ion gun, 11 is a shutter, 12 is a rotating shaft,
13 is a baked flange, 14 is a frame, and 15 is X
The line, 16 is a monochromatic X-ray.

In FIG. 1, a supporting member 2 is supported by a bakeable flange 13 that is airtightly attached to a frame 14, a pedestal 2 is attached to this, and a dispersive crystal 4 is adhered to the surface thereof. The dispersive crystal 4, the X-ray generator 1, and the sample 6 set on the sample stage 5 are arranged on a Rowland circle. Further, an etching ion gun 10 is attached to the frame 14 of the apparatus so that the sample surface can be etched, and the apparatus needs to have an ultrahigh vacuum of about 1 × 10 ^-10 Torr. The seed heater 9 is heated to about 200 ° C. to bake out. Photoelectrons emitted when the sample 6 is irradiated with the monochromatic X-ray 16 are detected by the detector 7. In this embodiment, a shutter 11 rotatable around the rotary shaft 12 is further provided, and the rotary shaft 12 is rotationally driven from the atmosphere side by a magnetic coupling, and the shutter 11 is used at the time of bakeout and ion etching. Cover the surface of the dispersive crystal.

In such a configuration, when the sample surface is etched by the etching ion gun 10 and the bake-out by the sheath heater 9 is performed as a pretreatment, the rotary shaft 12 is rotationally driven from the atmosphere side and the shutter 11 causes the spectroscopic crystal 4 to rotate. Cover the surface of. By doing so, it is possible to shield the radiant heat of the sheath heater 9 and prevent the element from adhering to the surface of the dispersive crystal by ion etching. After such pretreatment, X-rays 15 are guided from the X-ray generator 1 to the surface of the dispersive crystal 4, and the monochromatic X-rays 16 reflected by the dispersive crystal in a predetermined angle direction are applied to the sample 6, and the sample 6 is irradiated. The emitted photoelectrons are detected by the detector 7.

FIG. 2 is a diagram showing another embodiment of the present invention. 20 is a slit, 21 is an observation window, and 22 is a fluorescent screen. This embodiment is the rotary shaft 1 in the embodiment of FIG.
In addition to the shutter 11 that rotates around 2, the fluorescent plate 22
The X-rays 15 from the X-ray generator 1 irradiate the fluorescent plate 22 to emit fluorescence when the dispersive crystal is covered with this shutter, and this light can be observed through the observation window 21. ..

In such a structure, when the X-ray generator 1 and the slit 20 are aligned and adjusted, the rotary shaft 12 is driven from the atmospheric side by magnetic coupling or the like to cover the spectroscopic crystal with the shutter 11 to generate X-rays. X-ray 15 from vessel 1
It is possible to perform the adjustment work while irradiating the fluorescent plate 22 with the X-ray and observing the light on the fluorescent plate through the observation window 21 to see whether or not the X-ray is effectively applied to the dispersive crystal. As described above, since the adjustment can be performed on the atmospheric side while visually observing, the adjustment time can be significantly shortened.

[0012]

As described above, according to the present invention, the radiant heat of the bake-out sheath heater is shielded by providing the shutter for covering the dispersive crystal, and the element is prevented from adhering to the dispersive crystal surface by ion etching. Therefore, it is possible to prevent a decrease in detection sensitivity.
Further, by providing the shutter with a fluorescent plate, the X-ray generator can be arranged on the Rowland circle and the adjustment work for moving the slit position can be performed on the atmosphere side while observing the fluorescence, resulting in a large adjustment time. It can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing a photoelectron spectrometer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... X-ray generator, 2 ... Support member, 3 ... Pedestal, 4 ... Spectroscopic crystal, 5 ... Sample stand, 6 ... Sample, 7 ... Detector, 9 ... Bakeout sheath heater, 10 ... Etching ion gun, 11
... Shutter, 12 ... Rotation axis, 13 ... Baking flange, 14 ... Frame, 15 ... X-ray, 16 ... Monochromatic X-ray, 2
0 ... Slit, 21 ... Observation window, 22 ... Fluorescent plate.

Claims (2)

[Claims] 1. A shutter for covering the surface of a dispersive crystal in a photoelectron spectroscopic device in which X-rays from an X-ray source are guided to a dispersive crystal and a sample is excited by X-rays monochromated by the dispersive crystal to detect photoelectrons. The X-ray monochromator is characterized in that the shutter is opened and closed from the atmosphere side. 2. The X-ray according to claim 1, further comprising a fluorescent plate provided on the shutter such that the X-ray from the X-ray source is applied to the fluorescent plate when the dispersive crystal is covered with the shutter. Monochromator.