The interaction of high-energy ion beams with matter is a unique physical process. Using a beam of accelerated particles, it is possible not only to selectively modify various materials, but also to perform characterization of the composition of materials, including microstructures. The accelerated ions range in a material depends on their energy, so it is possible to control the parameters of the modified structure and, if necessary, implant individual isotopes of elements.
1) Ion implantation
High energy ion injection might imply formation of new material not in thermodynamic equilibrium bypassing normal chemical solubility rules. That provides a possibility to achieve defects just in desired place of the sample and at levels, which are inaccessible by conventional treatment.
Therefore, implantation process might be performed to tune properties of complex materials (e.g., nanostructures) or devices locally and at desired depth after their synthesis is finished. The control of created defect introduction and their evolution during implantation performed by in situ measurements.
a) Implantation of various positive ions with energy from 0.7 to 5 MeV using ion accelerator, e.g.:
• H+, C+, S+ N+, Si+, O+, Mg+, Zn+, Cu+, Ge+, Ga+, As+, etc. up to 70 mikrometer depth depending on the type of target material and ion energy;
• Implantation of different charge state ion species, e.g.: C+ C2+ C3+ C4+.
b) Implantation of negative ions with energy up to 30 MeV using ion source Hiconex, e.g.:
• Various negative ion species - H-, C-, S- N-, Si-, O-, Mg-, Zn-, Cu-, Ge-, Ga-, As- , etc.
• Molecular (polyatomic) beams: Al-, Al2-.
c) Ion implantation optimization according to the following post-impantation processes peculiarities for the creation and following implementation of new technologies for materials and their complex structures modification, e.g.:
• Theoretical simulation of implantation process before experiment;
• decreasing ion implantation current up to pA increasing implantation time and vice versa – shortened implantation time with relatively higher ion fluence;
• using implantation of several ions at various depth to the same target;
• using different energy for the same ion species (contact formation process), etc.
d) Possible correction of carriers lifetime in the particular depth of the completely formed semiconductor structures.
2) Material analysis
a) Particular matters quantitative (relative units %, ‰) and qualitative (abs units using NIST and other standards) concentration measurements using Particle induced x-ray emission (PIXE) method for elements heavier that Mg.
Canberra 7905-BWR bellows-sealed windowless retractable cryostat is used for PIXE experiments. It has lithium-drifted silicon 30 mm2 active area, detector resolution (FWHM) is 165eV at 5.894keV for 55Fe X-ray peak.
b) Chemical elements concentration profiling up to 30um depth using Rutherford backscatering spectroscopy (RBS) method.
ORTEC CR-015-050-100 is used for backscattering experiments. It has 15 keV alpha resolution (FWHM) at 5.486 MeV energy and 50 mm2 active area.
c) Stechiometric and impurities measurements in oxide and other layers using combined RBS and PIXE method.
d) Quantitative analysis of heavy metals in aerosol filters using PIXE method.
e) Ion induced luminescence measurements during ion irradiation.
3) Various types of test for research and cosmos technologies
a) Irradiation of electronics, optics, avionics systems or their parts using protons up to 2MeV and heavier ions up to 5MeV.
b) Materials or parts degassing process in vacuum dynamics and characterization.
c) Various types of experiments in vaccum chamber with sample cooling/heating and power/signal cable inlet capabilities for test of various prototypes .
d) Materials irradiation in athmospheric conditions using proton beam.
4) Design, service and repair of low (100kPa-3.3kPa), middle (3.3kPa-130mPa), high (130mPa-130µPa) iand super-high (130µPa-130nPa) vacuum systems
5) Design and service of various gas supply and pneumatic control systems
Contact person:
Dr. Vitalij Kovalevskij
vitalij.kovalevskij@ftmc.lt