The objective of the study is to provide PhD education to MSc graduates in all partial fields and to create a cross-disciplinary overview of the present development, to develop theoretical foundations in the selected research area, to master the methods of scientific, to develop their creative abilities and to use them for the solution of research problems. This all should lead to a dissertation thesis, which will provide an original a significant contribution to the research status in the field of interest.

Graduates of this program will acquire cross-disciplinary knowledge of and experience in technical and physical subjects on a high-quality theoretical level. Graduates are for their later independent research and development work equipped with the knowledge and experience from, in particular, physics of semiconductors, quantum electronics and mathematical modeling and will be able to independently solve problems associated with nanotechnologies. Potential job careers: research worker in basic or applied research and in the introduction, implementation and application of new prospective and economically beneficial procedures and processes in the field of electronics, electrical engineering, non-destructive testing and reliability and material analysis.

Graduates of this program will acquire cross-disciplinary knowledge of and experience in technical and physical subjects on a high-quality theoretical level. Graduates are for their later independent research and development work equipped with the knowledge and experience from, in particular, physics of semiconductors, quantum electronics and mathematical modeling and will be able to independently solve problems associated with nanotechnologies. Potential job careers: research worker in basic or applied research and in the introduction, implementation and application of new prospective and economically beneficial procedures and processes in the field of electronics, electrical engineering, non-destructive testing and reliability and material analysis

prof. RNDr. Pavel Tománek, CSc.

1. Llight polarization and scattering methods for diagnostics of biological tissues

   Study of structural and optical models of tissues with single and multiple scattering with ordered and randomly distributed scatterers. Study of polarization states of forward and backward scattered light. Data processing by macroscopic and microscopic methods - as Monte Carlo.

   Tutor: Tománek Pavel, prof. RNDr., CSc.

2. RTS noise in MOSFETs

   The aim of this project is to determine parameters of traps in insulation layer of submicron MOSFETs by analysis of its noise characteristics, mainly RTS (random telegraph signal) noise. Experimental work is based on measurement of temperature dependence of noise using helium cryostat and study of amplitude and mean time of capture and emission as a function of electric field intensity and charge carrier concentration in channel. These results will be used to improve generation-recombination model of noise origin and localization of traps.

   Tutor: Pavelka Jan, doc. Mgr., CSc. Ph.D.

3. Study of dielectric and insulating materials with low permittivity

   Decreasing the dimensions in integrated circuits (currently 32 nm) brings about an increase of interconnect capacitance and thus the reduction of the signal propagation speed. The limiting factor for a further improvement of electronic device performance thus become not the properties of semiconductor devices themselves but rather interconnect delays and, hence, too high magnitudes of parasitic capacitances. One of the options for the reduction of interconnect capacitances is the reduction of the permittivity (dielectric constant, k) of thin-layer insulating layers (capacitance is directly proportional to permitivity). Two major routes are available: replacement of polar Si-O bonds with less polar Si-F or Si-C bonds or raising the porosity (intentional introduction of air voids). The newly developed low-k materials must, however, not limit the currently used silicon technologies and must be able to pass all manufacturing steps (temperatures up to about 1100°C). The work on this topic will require experimental work in sample preparation and design, studies of the theory of low-k dielectrics and the measurement of electrical properties of developed material systems. What is available: measurement equipment for the frequency range 10-3 – 109 Hz and the helium cryostat for the temperature range 10 – 500 K.

   Tutor: Liedermann Karel, doc. Ing., CSc.

4. Study of high-k dielectric materials based on copper titanates

   The topic of the dissertation is the investigation of electrical properties of CCTO ceramics (i.e., based on CaCu3Ti4O12), doped with transition metals and lanthanides. Attention will be focused toward the identification of mechanisms leading to high dielectric constant (permittivity) of the order 10^4 – 10@5 and, subsequently, on the modification of CCTO ceramics formulation in order to reduce dielectric loss and to extend the frequency interval, in which the dielectric constant retains its high value, up to the GHz range Materials exhibiting high permittivity are needed for new applications, particularly in integrated circuits and in capacitors. In capacitors, high-k dielectrics are used in order to attain higher energy densities and thus to reduce the size of capacitors themselves. The work on this topic will require experimental work in sample preparation and design, studies of the theory of high -k dielectrics and the measurement of electrical properties of developed material systems. What is available: measurement equipment for the frequency range 10^2 – 10^9 Hz and Janis helium cryostat CCS-400/204 for the temperature range 10 – 500 K. Purchased, yet not operated are Novocontrol ALPHA-AT high-resolution high-frequency analyzer with frequency range 3 microHz – 40 MHz and Nicolet 8700 FTIR-spectrometer with wave number range 20 000 – 350 cm-1.

   Tutor: Liedermann Karel, doc. Ing., CSc.

5. Study of nanocomposites for electrical insulation

   The subject of the research will be dielectric properties of nanocomposites for electrical insulation. These materials are based on thermosetting resins, mostly epoxides, containing finely dispersed SiO_2, TiO_2, Al_2O_3 or WO_3 microfillers and nanofillers, eventually more complex chemical formulations. The presence of nanoparticles with dimensions of some 10 – 20 nm favorably affects the withstand capability of nanocomposites to partial discharges and electrical treeing and, hence, the breakdown strength as well as the degradation resistance. This in turn brings the possibility to manufacture electrical equipment (e.g. switchgear, vacuum interrupters) with smaller dimensions and weight and improved reliability. An important issue concerning all nanocomposites is the presence of a large number of interfaces. They are to due to the presence of nanoparticles with complex shapes (neither planar nor spherical). These interfaces exhibit a low stability, which may later cause substantial changes of electrical properties in the course of ageing. One of the objectives of the proposed research would therefore be to study the behavior of nanocomposites in the course of accelerated ageing. The work on this topic will require experimental work in sample preparation and design, studies of the relation between microphysical structure and electrical properties and the measurement of electrical properties of developed material systems. Equipment currently available in the Department of Physics: measurement equipment for the frequency range 10^2 – 10^9 Hz and Janis helium cryostat CCS-400/204 for the temperature range 10 – 500 K, as well as established software for measurement control. Purchased, yet not operated are Novocontrol ALPHA-AT high-resolution high-frequency analyzer with frequency range 3 microHz – 40 MHz and Nicolet 8700 FTIR-spectrometer with wave number range 20 000 – 350 cm-1.

   Tutor: Liedermann Karel, doc. Ing., CSc.