JPH057823B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention irradiates a sample surface with both an ion beam and an electron beam, and scrapes the sample surface with the ion beam while irradiating the sample with the electron beam. Energy analysis of Auger electrons emitted from an excited sample, spectroscopic analysis of X-rays emitted from the sample, and mass spectrometry of secondary ions emitted from the sample surface by ion beam irradiation. This invention relates to a composite analysis device that can perform various analysis methods such as the following.

(b) Prior art Conventionally, in analyzers that perform Auger electron spectroscopy while performing ion etching, the ion gun Gi and electron gun Ge are separate, as shown in Figure 1, and the ion gun is focused on the sample surface. The ion optical system and the electron optical system that converges the electron beam onto the sample surface were configured such that their respective optical axes Ai and Ae intersected on the sample S surface. Needless to say, in this type of analyzer, the ion beam and electron beam must be designed to irradiate the same spot on the sample surface, but the conventional equipment described above requires an ion optical system and an electron optical system. Since the beams are separated from each other, it is extremely difficult to adjust the equipment so that both beams illuminate the same spot on the sample surface, and a great deal of effort is expended on the adjustment. Additionally, AM is an energy analyzer for Augier electron spectroscopy, but since the ion source device occupies space, it is difficult to find space for other analysis devices.

(C) Purpose The purpose of the present invention is to provide an analyzer using two types of charged particle beams, with a configuration in which the two types of charged particle beams inevitably irradiate the same part of a sample. This eliminates the difficulty of adjusting the two types of beams mentioned above to irradiate the same spot on the sample surface, increases the space utilization rate, and makes it possible to create a complex analysis device like the one mentioned at the beginning. did.

(d) Configuration When negative ions are extracted from the ion gun, electrons are also extracted at the same time. The present invention focuses on this point,
An ion gun and an electron gun are shared, and an electrostatic lens and a magnetic lens are arranged on one optical axis that includes the shared gun, and the ion beam and electron beam are coaxially formed to irradiate the sample. The purpose of the present invention is to provide a composite analysis device designed to do the following.

For example, when extracting negative ions using a Duoplasmatron as an ion source, the ion current is about 10 μA when operated at 10 KV, whereas the electron current is about 1 mA. For the same accelerating voltage,
Electrostatic lenses exhibit the same optical properties for both ions and electrons, but magnetic lenses have different optical properties depending on the mass of the charged particles. Therefore, by arranging an electrostatic lens and a magnetic lens on one axis, the ratio of negative ions and electrons extracted from the same gun can be controlled arbitrarily, and the same part of the sample can be targeted with an ion beam and an electron beam. It becomes possible to irradiate.

(e) Embodiment FIG. 2 shows an embodiment of the present invention. 1 is an ion source dual plasmatron that serves as both an ion gun and an electron gun. 21, 22 are magnetic lenses, 31,
32 is an electrostatic lens, and these are arranged on the optical axis A that includes the ion source 1. S is a sample. 4
5 is a charged particle energy analyzer, and 5 is an electron detector. The energy analyzer 4 is installed so as to face the intersection O between the surface of the sample S and the optical axis A.
Of the electrons emitted from point O, those with a specific energy that corresponds to the DC voltage applied to the energy analyzer 4 converge on the slit 6, and the DC voltage applied to the energy analyzer 4 converges on the slit 6. An Auger electronic detection signal can be obtained by superimposing a minute amplitude AC voltage on the voltage and extracting an AC component of the same frequency from the output of the electronic detector 5. In the figure, the electron detector 5 is a quadrupole mass spectrometer,
If the configuration is such that an ion detector is arranged after that, when the sample S is irradiated with an ion beam, it is possible to perform mass analysis of secondary ions emitted from the sample. As a practical matter, it is structurally difficult to replace the electron detector 5 with a quadrupole mass spectrometer.
Although not shown in this embodiment for reasons of illustration, an energy analyzer for secondary ion mass spectrometry is installed so as to face point O, and a mass spectrometer and an ion detector are placed behind it. 7 is a spectroscopic crystal for dispersing the X-rays emitted from point O on the sample S; 8
is an X-ray detector, and these constitute an X-ray spectrometer that looks at the O point.

FIG. 3 is a diagram illustrating the operation of the ion and electron optical systems in the above embodiment. In the figure, I shown by a solid line is an ion beam, and E shown by a dotted line is an electron beam. Ions and electrons emitted from the ion source 1 have the same energy because they are accelerated by the same acceleration voltage. In such a case, the magnetic lens has little effect on ions whose mass is significantly larger than that of electrons, and only the electron beam E is focused on point F1 by the magnetic lens 21. An aperture 9 is arranged within the magnetic lens 22, and by adjusting the strength of the lens 21 and changing the distance between the F1 point and the aperture 9, the current of the electron beam passing through the aperture 9 can be adjusted. can do. The magnetic lens 22 has an aperture of 9
The spread angle α of the electron beam that has passed through the ion beam I is made to substantially match the spread angle β of the ion beam I, and a virtual image of the electron beam at point F1 is formed in the ion-electron common line source Q. The ion beam and electron beam, whose spread angles match in this way, are influenced by the electrostatic lenses 31 and 32 in exactly the same way, and are converged to point O on the sample S.

(f) Effects As described above, the present invention uses a common ion source and an electron source in an analyzer that irradiates a sample with an ion beam and an electron beam, and the electron beams are focused on the sample by the same optical system. It is possible to accurately irradiate the same point on the sample with the ion beam and electron beam without the difficult assembly and adjustment work as in the example above, and since the ion optical system and electron optical system are common, the entire periphery of the sample can be irradiated with the ion beam and electron beam. can be used as a space for various analytical devices, and can be used not only for Auger electron spectroscopy while removing the sample surface by ion etching, but also for X-ray electron spectroscopy.
Various analysis methods such as line spectroscopy and secondary ion mass spectrometry can be performed simultaneously.

[Brief explanation of the drawing]

FIG. 1 is a side view of a conventional device, FIG. 2 is a side view of an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the operation of the charged particle beam optical system of the same embodiment. 1...Ion source that serves as both an ion source and an electron source, 2
1, 22... Magnetic lens, 31, 32... Electrostatic lens, 4... Energy analyzer, 5... Electron detector, 7... X-ray spectroscopy crystal, 8... X-ray detector, 9
...Aperture, S...Sample, E...Electron beam, I...
...Ion beam.

Claims (1)

[Claims] 1. An ion source device that serves as both an ion gun and an electron gun, a magnetic lens and an electrostatic lens that are placed on one optical axis including this ion source device, and an ion source on the sample surface that is placed on the optical axis. It consists of multiple types of analyzers placed around the same sample so as to face the beam and electron beam irradiation points, and two axial lenses and an aperture are placed on the optical axis near the ion source device. Then, an electrostatic lens is placed below these magnetic lenses and the aperture, and the upper magnetic lens converges the electron beam between the upper and lower magnetic lenses on the optical axis, and the position of the convergence point is adjusted. A composite analyzer characterized in that a virtual image of the convergent point is formed at the position of the ion point source of the ion source device by a lower magnetic lens.