Jan Szmidt

Dr. Jan Szmidt

Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Warsaw, Poland

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 December 2024 in Materials
Verified
Journal Article
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MKMaciej Kaminski
Maciej Kaminski
KKKrystian Król
Krystian Król
NKNorbert Kwietniewski
Norbert Kwietniewski
MMMarcin Myśliwiec
Marcin Myśliwiec
MSMariusz Sochacki
Mariusz Sochacki
ASAndrzej Strojwas
Andrzej Strojwas
Arguably, SiC technology is the most rapidly expanding IC manufacturing technology driven mostly by the aggressive roadmap for battery electric vehicle penetration and also industrial high-voltage/high-power applications. This paper provides a comprehensive overview of the state of the art of SiC technology focusing on the challenges starting from the difficult and lengthy SiC substrate growth all the way to the complex MOSFET assembly processes. We focus on the differentiation from the established Si manufacturing processes and provide a comprehensive list of references as well as a brief description of our own research into the key manufacturing processes in this technology. We also present a SiC technology and product roadmap.

11 February 2020 in Journal of Applied Physics
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ŁGŁ. Gelczuk
Ł. Gelczuk
MDM. Dąbrowska-Szata
M. Dąbrowska-Szata
VKVl. Kolkovsky
Vl. Kolkovsky
MSMariusz Sochacki
Mariusz Sochacki
JSJan Szmidt
Jan Szmidt
TGTeodor Gotszalk
Teodor Gotszalk
Several deep level defects were observed by conventional deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS (LDLTS) in n-type 4H-SiC junction barrier Schottky diodes. We have shown that the broad DLTS peak labeled Z1/2 has, in fact, two components, Z1 and Z2, with activation enthalpies for electron emission of 0.63 eV and 0.68 eV, respectively. The reorientation process between these two components was observed. A combination of double-correlated DLTS and LDLTS demonstrated an anomalous reduction of the emission rate and an increase of the activation enthalpy of Z2 with an increase of the reverse bias applied to the diode. The possible explanation of this phenomenon could be correlated with a tensile stress in epitaxial SiC layers. The results observed are discussed in the frame of the model that correlates Z1 and Z2 with carbon vacancies (VC), located at hexagonal (h) and cubic (k) lattice sites, respectively. We also discussed the origin of other traps E0–E5 with particular emphasis on a N-related shallow donor level located at 0.04 eV below the conduction band, which has never been previously reported by DLTS studies.

21 September 2022 in Materials
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Michal MazurMichal Mazur
Michal Mazur
AOAgata Obstarczyk
Agata Obstarczyk
WPWitold Posadowski
Witold Posadowski
JDJaroslaw Domaradzki
Jaroslaw Domaradzki
SKSzymon Kielczawa
Szymon Kielczawa
JSJan Szmidt
Jan Szmidt
The paper presents the results of an investigation of the influence of technological parameters on the microstructure, optical, electrical and nanomechanical properties of zinc oxide coatings prepared using the pulsed reactive magnetron sputtering method. Three sets of ZnOx thin films were deposited in metallic, shallow dielectric and deep dielectric sputtering modes. Structural investigations showed that thin films deposited in the metallic mode were nanocrystalline with mixed hexagonal phases of metallic zinc and zinc oxide with crystallite size of 9.1 and 6.0 nm, respectively. On the contrary, the coatings deposited in both dielectric modes had a nanocrystalline ZnO structure with an average crystallite size smaller than 10 nm. Moreover, coatings deposited in the dielectric modes had an average transmission of 84% in the visible wavelength range, while thin films deposited in the metallic mode were opaque. Measurements of electrical properties revealed that the resistivity of as-deposited thin films was in the range of 10−4 Ωcm to 108 Ωcm. Coatings deposited in the metallic mode had the lowest hardness of 2.2 GPa and the worst scratch resistance among all sputtered coatings, whereas the best mechanical properties were obtained for the film sputtered in the deep dielectric mode. The obtained hardness of 11.5 GPa is one of the highest reported to date in the literature for undoped ZnO.

28 October 2014 in International Journal of Electronics and Telecommunications
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ATAndrzej Taube
Andrzej Taube
MSMariusz Sochacki
Mariusz Sochacki
JSJan Szmidt
Jan Szmidt
EKEliana Kaminska
Eliana Kaminska
APAnna Piotrowska
Anna Piotrowska
The article presents the results of modelling and simulation of normally-off AlGaN/GaN MOS-HEMT transistors. The effect of the resistivity of the GaN:C layer, the channel mobility and the use of high-κ dielectrics on the electrical characteristics of the transistor has been examined. It has been shown that a low leakage current of less than 10-6 A/mm can be achieved for the acceptor dopant concentration at the level of 5 × 10 15 cm-3. The limitation of the maximum on-state current due to the low carrier channel mobility has been shown. It has also been demonstrated that the use of HfO2, instead of SiO2, as a gate dielectric increases on-state current above 0.7A/mm and reduces the negative influence of the charge accumulated in the dielectric layer.

25 October 2013
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Michal BoreckiMichal Borecki
Michal Borecki
AKAndrzej Kociubinski
Andrzej Kociubinski
MDM Duk
M Duk
NKNorbert Kwietniewski
Norbert Kwietniewski
MKM Korwinpawlowski
M Korwinpawlowski
JSJan Szmidt
Jan Szmidt
This paper describes the construction, fabrication and properties of large-area ultra violet detector that is transparent in the visible range. The device was made on n-type 4H SiC substrate with a double epitaxial layer in which aluminum was implanted to form a p-n junction close to the surface, and a SiO2 layer was formed for passivation, without a guard ring. The design of the top and bottom electrodes of 4mm diameter UV sensitive area allows not less than 20% visible range transmission. This transmission was measured across sensitive area of examined devices and was only 5% lower than that of the substrate before implantation and electrodes deposition.

24 August 2022 in Materials
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STSylwia Terpilowska
Sylwia Terpilowska
SGStanislaw Gluszek
Stanislaw Gluszek
ECElzbieta Maria Czerwosz
Elzbieta Maria Czerwosz
HWHalina Wronka
Halina Wronka
PFPiotr Firek
Piotr Firek
RDRyszard Diduszko
Ryszard Diduszko
The application of nano-Ag grains as antiviral and antibacterial materials is widely known since ancient times. The problem is the toxicity of the bulk or big-size grain materials. It is known that nano-sized silver grains affect human and animal cells in some medical treatments. The aim of this study is to investigate the influence of nano-Ag grains embedded in a carbonaceous matrix on cytotoxicity, genotoxicity in fibroblasts, and mutagenicity. The nanocomposite film is composed of silver nanograins embedded in a carbonaceous matrix and it was obtained via the PVD method by deposition from two separated sources of fullerenes and silver acetate powders. This method allows for the preparation of material in the form of a film or powder, in which Ag nanograins are stabilized by a carbon network. The structure and morphology of this material were studied using SEM/EDX, XRD, and Raman spectroscopy. The toxicology studies were performed for various types of the material differing in the size of Ag nanograins. Furthermore, it was found that these properties, such as cell viability, genotoxicity, and mutagenicity, depend on Ag grain size.