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The electrical and physical properties of the SiC/SiO2 interfaces are critical for the reliability and performance of SiC-based MOSFETs. Optimizing the oxidation and post-oxidation processes is the most promising method of improving oxide quality, channel mobility, and thus the series resistance of the MOSFET. In this work, we analyze the effects of the POCl3 annealing and NO annealing processes on the electrical properties of metal–oxide–semiconductor (MOS) devices formed on 4H-SiC (0001). It is shown that combined annealing processes can result in both low interface trap density (Dit), which is crucial for oxide application in SiC power electronics, and high dielectric breakdown voltage comparable with those obtained via thermal oxidation in pure O2. Comparative results of non-annealed, NO-annealed, and POCl3-annealed oxide–semiconductor structures are shown. POCl3 annealing reduces the interface state density more effectively than the well-established NO annealing processes. The result of 2 × 1011 cm−2 for the interface trap density was attained for a sequence of the two-step annealing process in POCl3 and next in NO atmospheres. The obtained values Dit are comparable to the best results for the SiO2/4H-SiC structures recognized in the literature, while the dielectric critical field was measured at a level ≥9 MVcm−1 with low leakage currents at high fields. Dielectrics, which were developed in this study, have been used to fabricate the 4H-SiC MOSFET transistors successfully. [ABSTRACT FROM AUTHOR]

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Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The origin of unintentional hydrogen incorporation in ZnO films grown by thermal atomic layer deposition is investigated by comparing layers deposited using H2O and D2O as oxygen precursors. Secondary ion mass spectroscopy measurements of as‐grown and 800 °C annealed layers provide evidence that the hydrogen contribution originating from the oxygen precursor is weakly chemically bound and is mostly removed by rapid thermal annealing conducted at 800 °C for 3 min in oxygen atmosphere. On the other hand, the remaining hydrogen introduced by ethyl groups originating from the metalorganic zinc precursor withstands such treatment. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Films of transparent semiconductors are widely studied and developed because of high potential applications in electronics in last decade. Our work concerns the properties of NiO films fabricated by RF magnetron sputtering. Electrical and optical parameters of the films were characterized using Hall and transmittance measurements, respectively. P-type conductivity of as-deposited films and after annealing in oxygen or argon at the temperature range from 300°C to 900°C was verified. Transmittance of NiO films strongly depends on deposition temperature and oxygen amount during sputtering. Films deposited at room temperature without oxygen have transmittance near 50% in the visible range and resistivity about 65Ωcm. An increase in oxygen amount in deposition gas mixture results in higher conductivity, but transmittance decreases below 6%. Resistivity of 0.125 Ωcm was attained at sputtering in oxygen. Films deposited at temperature elevated up to 500°C are characterized by transmittance above 60% and lower conductivity. Annealing of NiO films in Ar causes resistivity to rise dramatically. [ABSTRACT FROM AUTHOR]

Low‐resistivity Ohmic contacts to Gallium‐face (G‐aface) and/or Nitrogen‐face (‐Nface) n‐GaN are undoubtedly needed for high‐quality vertical power devices. Contrary to Ga‐face n‐GaN, for which the Ohmic contact formation is a well‐established process, the formation of low‐resistivity Ohmic contacts to N‐face n‐GaN is much more difficult due to the different surface properties. Despite many efforts, obtaining low‐resistivity ohmic contacts, with ρc < 1 × 10−5 Ω cm2 to N face n‐GaN, still remains difficult to achieve. Herein, results of fabrication and characterization of Ti/Al/TiN/Au ohmic contacts to Ga‐ and N‐face n‐GaN for vertical power devices are presented. The optimum annealing temperature is examined and it is noticed that Ohmic contacts to Ga‐face n‐GaN (n ≈ 5 × 1018 cm−3 , 200 nm on bulk GaN substrate) are formed after 550 °C annealing and continuously lower their ρc up to temperature of 750 °C for which ρc is ≈1.86 × 10−6 Ω cm2. Ohmic contact to N‐face n‐GaN (bulk ammonothermally grown substrate, ρ ≈ 10−3–10−2 Ω cm2) becomes quasilinear after annealing at 650 °C and becomes linear after annealing at 700 °C, reaching a minimum value of ρc 6 × 10−6 Ω cm2. Further annealing at higher temperaturesincreases the contact resistivity to the value of ≈5.8 × 10−5 cm2 for annealing at 800 °C. The electrical measurements results were accompanied with the results of structural characterization for determination of Ohmic contact formation mechanism. [ABSTRACT FROM AUTHOR]