SU957317A1 - Energomass analyzer - Google Patents

Description

(54) ENERGY MASSANALIZER

one

The invention relates to physical instrumentation, in particular, to devices for analyzing ions by mass and energy, and can be used to analyze the surface layers of materials using various methods of ion spectroscopy. five

To analyze the methods of ionic spectroscopy of the elemental composition, crystallographic and electronic structure of the surface, as well as radiation orientation Q and the nature of the interaction of the adsorbed layers and film condensates with the substrate, it is necessary to know the angular distributions of the intensities of the primary ions scattered by the surface and - 15 surface irradiation by the flow of primary ions. In this case, for the analysis of materials with anisotropy of physical and physicochemical properties, the measurement of the angular distributions must be made 2o simultaneously with the analysis of the distribution of ions by energy and mass.

The lack of data on any of the distributions (by mass, energy, or angles) does not allow obtaining a complete picture of the surface of the object under study.

A spectrometer is known that permits analysis of ions scattered by a surface at angles and energies. The spectrometer contains a source of primary ions, means for focusing the primary ion beam on the sample surface, the sector spherical energy analyzer and the ion detector are located along the beam of the analyzed ions. At the input of the energy analyzer, there is a collimating and retarding beam of the analyzed ions, a system that allows the selection of ions with a certain angle of emission from the surface. This system, the energy analyzer and the ion detector are mounted on a turntable and can rotate around the analyzed surface, which makes it possible to change the direction of selection of the primary ions scattered by the surface 1 or emitted by it.

Claims (2)

A disadvantage of the known device is the lack of ion resolution by weight, which limits its analytical capabilities, reduces the accuracy and efficiency of the sample surface analysis, especially when working with multicomponent materials. The energy mass analyzer closest to the proposed one contains an ion source placed in a vacuum chamber, an ion beam focusing system on the target surface, a sector energy analyzer and a mass analyzer along the beam path of the analyzed particles, as well as an ion detector. The sample under investigation can be rotated relative to the source of the bombarding ions with a precision manipulator, which provides surface analysis at different angles of incidence of bombarding ions 2. The disadvantage of this device is the limited analytical possibilities of studying the surface, since the analysis of particles is carried out only in energy and mass. In devices of this type, the possibility of analyzing ions emitted or scattered by the surface layer of a material by their angular distribution is not realized. This is due to the fact that in order to realize the possibility of analyzing ions in the corners, it is necessary to rotate the energy and mass analyzers around the sample either directly into the vacuum chamber or outside it, connecting the analyzers with it by some flexible vacuum-tight joint. Both are technically difficult to do. The purpose of the invention is to expand the analytical capabilities of the device by analyzing the ions by angle. The goal is achieved by the fact that an ion-deflecting device located between the energy analyzer and the mass analyzer and the energy analyzer are rotatable around an axis, the continuation of which is an ion-deflecting device, placed in series in the energy-mass analyzer containing the ion source with the focusing system. The ion-optical axis of the mass analyzer. Such an energy mass analyzer makes it possible, in addition to analyzing ions by energies and masses, to analyze cones by their angular distribution, which greatly improves the analytical capabilities of the device, increases the versatility, the efficiency of the device, its sensitivity to the surface condition and the accuracy of surface analysis at any angles irradiation and selection of the analyzed ions. The drawing shows the device sche. The energy-mass analyzer contains an ion source 2 placed in a vacuum chamber 1, an ion beam focusing system 3 on sample 4, a collimating and slowing system 5 located at the entrance of a hemispherical energy analyzer 6 located along the beam of analyzed particles, a deflecting device 7 made for example, in the form of a flat capacitor, and installed at the output of the energy analyzer 6. A mass analyzer 8 and an ion detector 9 are located behind the deflecting device 7 in the direction of movement of the analyzed particles. The externally controlled manipulator 10 rotates the sample 4 at any angle relative to the direction of incidence of the beam of bombarding ions. The collimating and retarding system 5, the energy analyzer 6 and the diverting device 7 are mechanically rigidly interconnected and placed on a turntable 11 mounted on a support bearing 12. The rotation of the platform 11 is carried out using an externally controlled mechanism 13 for transmitting the rotation and counting the angles rotation, which ensures the rotation of the energy analyzer 6 at any angle relative to the normal to the sample surface 4. The rotation of the rotary platform 11 is carried out around the optical axis A-A, the direction of which This coincides with the axis of rotation of the sample surface 4, passing through the point of incidence of the beam of bombarding ions, as well as with the direction of exit of the analyzed ions from the deflecting device 7 and with the ion-optical axis of the mass analyzer 8. The device works as follows. The ion beam is generated by a source of 2 ions, for example, an electron impact ionized source, and is focused with the help of the system 3 focusing on the surface of the test sample 4. The required angle between the normal to the sample surface and the direction of ion bombardment is established by means of a manipulator 10. Dispersed or emitted the secondary ions pass through the collimating and slowing system 5, which limits the angle of selection of the Aai ions, thereby determining the criminal resolution of the analysis, and enter the hemisphere esky energy analyzer 6, which are subjected to analysis by energy meters by variations in the electric field of appropriate configuration. Particles emerging from the hemispherical energy analyzer 6 enter the deflecting device 7, which deflects the particles along the direction of the axis А-А passing through the point of incidence of the bombarding ion beam and coinciding with the axis of rotation of the energy analyzer 6 and the ion-optical axis of the mass analyzer 8. Required The angle of selection of the analyzed particles ОС is determined by the mechanism 12 of the transmission of rotation, located outside the vacuum chamber 1, by rotating the platform 11 on the support bearing 12 around the axis AA. In so doing, the analyzed particles leaving the deflecting device 7, enter the mass analyzer 8 and are then recorded with the aid of the ion detector 9. The proposed device has improved analytical capabilities as compared with the known one, since it enables the simultaneous analysis of ions by energy and mass, as well as the analysis of the angular distributions of ions in the range of any surface irradiation angles and any selection angles of the analyzed ions. This, in turn, allows one to comprehensively investigate the surface of a solid, to increase the efficiency and sensitivity of the analysis. Thus, the accuracy of analysis of the crystallographic structure of single crystals by the proposed device is increased by 10, times, the accuracy of analysis of the bonding forces of surface atoms by 6 times, compared to the prototype. In addition, the resolution (while maintaining the luminosity) of the energy analyzer of the proposed device is higher than that of the prototype, due to the additional energy analysis of the ions in the rotator, made in the form of a flat capacitor. The factors listed above make the proposed device universal and suitable for analyzing a multithread surface by progressive methods: mass spectrometry of secondary ions, ion scattering spectroscopy, ion channeling methods, etc. The invention is particularly promising when analyzing materials used in semiconductor, emission and cryogenic electronics, nuclear engineering, space materials science, and other areas of technology where massive and film solid objects are used, possessing no anisotropy of physical and physico-technical properties. An energy analyzer comprising an ion source with a focusing system and sequentially arranged energy analyzer, mass analyzer and detector, characterized in that, in order to expand the analytical capabilities, an ion-deflecting device located between the energy analyzer and the mass analyzer is introduced into it, and the energy analyzer is made with the possibility of rotation around the axis, the continuation of which is the ion-optical axis of the mass analyzer. Sources of information taken into account in the examination 1. Combined spectrometer ADES-400 of the company VG Scientific. Prospectus and technical description. 2. Published in the Federal Republic of Germany No. 2313852, cl. G 01 N 23/22, 1968