Phone: þ48 22 5487942 1 Â 10 8 V/&, respectively for C and Al implantation. Characterization by XRD, Raman and photoluminescence spectroscopy provides evidence that implantation damages the crystal lattice, yielding insulating properties. It is demonstrated that the isolation is stable up to 600 8C. We also demonstrate AlGaN/GaN HEMTs on semi-insulating Ammono-GaN substrates working both in DC (I DS ¼ 800 mA/mm) and RF (up to 6.5 GHz) mode with isolation prepared by means of the described approach.

Investigation of the cut location in hydrogen implantation induced silicon surface layer exfoliation

With the development of novel device applications, e.g. in the field of robust and recyclable paper electronics, came an increased demand for the understanding and control of IGZO Schottky contact properties. In this work, a fabrication and characterization of flexible Ru-Si-O/ IGZO Schottky barriers on paper is presented. It is found that an oxygen-rich atomic composition and microstructure of Ru-Si-O containing randomly oriented Ru inclusions with diameter of 3-5 nm embedded in an amorphous SiO 2 matrix are effective in preventing interfacial reactions in the contact region, allowing to avoid pre-treatment of the semiconductor surface and fabricate reliable diodes at room temperature characterized by Schottky barrier height and ideality factor equal 0.79 eV and 2.13, respectively.

Although Ta2O5 is thermodynamically the most stable form of TaxOy, the chemical composition/stoichiometry of TaxOy films may generally be complex. On the other hand, to be robust in harsh chemical environments, the film material is required to be amorphous rather than crystalline. The amorphousness of atomic layer deposited (ALD) films is promoted by low process temperature generally. This paper presents the study on TaxOy films deposited by ALD at low temperature (100 °C) using TaCl5 and H2O as chemical precursors, bringing the compositional, structural, and optical properties of the films together. The films with the thickness in the range of 32–202.5 nm were deposited mostly on Si (100) wafers. For their characterization, secondary ion mass spectroscopy, Rutherford backscattering spectroscopy, x-ray photoelectron spectroscopy, x-ray diffractometry, and spectroscopic ellipsometry were performed. The films were overstoichiometric in relation to Ta2O5, with the O/Ta ratio in the range of 2.7–2.8. Additionally, some amount of surface O was bound within adsorbed -OH and -CO groups. The main contaminant of the films was Cl (5–5.5 at. %). The main contaminant of their surfaces and at the film/substrate interfaces was carbon (>50 at. %). All the films proved to be fully amorphous. Their real part of refractive index was very similar (n approximately 2) in the whole range of thicknesses, with differences of a few percent only. Optical attenuation was negligibly low.

The substrate of choice for high power microwave GaN-based devices is silicon carbide. However recently novel semi-insulating truly bulk GaN substrates with excellent crystalline and electrical parameters have been developed by Ammono S..A. These allow to elaborate AlGaN/GaN heterostructures with high electron mobility values and density of two-dimensional electron gas. Developed processing steps, especially planar isolation by ion implantation and formation of low resistivity regrown ohmic contacts enabled fabrication of high quality devices. An 1000 mA/mm on-state current density along with low 4.4 Ω/mm on-state resistance were achieved. For the devices with rectangular, 0.8 μm gate length the fMAG and fs were 31 GHz and 22 GHz. The maximum output power density was more than 4.15 W/mm in S-band.